Horticulturae doi: 10.3390/horticulturae12050549

Authors: Yang Li Mengwei Huang Yuxin Chen Ruohan Jin Dandan Cui Juanqi Li Shengli Li

The toxicity of copper (Cu) severely affects the growth and physiological metabolism of plants. 2-(3,4-Dichlorophenoxy) triethylamine (DCPTA) is a plant growth regulator known to enhance plant tolerance to various abiotic stresses; however, its specific role in mitigating Cu toxicity via cell wall modulation and nitrogen metabolism remains unclear. “Zhongnong 26” (Cucumis sativus L.) seedlings were subjected to a randomized block design with four treatments: control (CK), 0.25 mg/L DCPTA, 50 μM Cu, and 50 μM Cu + 0.25 mg/L DCPTA, with three biological replicates per treatment. The results indicated that DCPTA application significantly alleviated Cu-induced growth inhibition. Specifically, DCPTA improved root system architecture by markedly increasing total root length (68.8%), surface area (68.7%), and the number and length of secondary lateral roots (69.6%, 173.2%). Furthermore, DCPTA enhanced the biosynthesis of cell wall polysaccharides—including pectin (24.3%), hemicellulose 1 (22.4%), hemicellulose 2 (23.7%) and cellulose (33.1%) in roots. Fourier Transform Infrared (FTIR) spectroscopy analysis revealed that DCPTA modified functional groups (e.g., –OH, –COOH) within the cell wall, enhancing their metal-chelating capacity. Consequently, DCPTA promoted the immobilization of Cu in the root cell wall fractions (particularly pectin and HC2) and shifted Cu into less toxic, pectate- and protein-bound forms, thereby reducing its translocation to leaves. Additionally, DCPTA restored the activities of key nitrogen metabolism enzymes in leaves and roots. Compared with Cu treatment alone, nitrate reductase (NR) activity increased by 77.7% and 90.6%, while glutamine synthetase (GS) activity remained stable, and glutamate synthase (GOGAT) activity increased by 10.3% and 71.3% in leaves and roots, respectively. In conclusion, DCPTA enhances copper sequestration in roots by coordinating the regulation of root structure and cell wall strengthening (with an increase in pectin and hemicellulose content). This is crucial for protecting the nitrogen metabolism within the cells (including the enzymes that drive the nitrate–ammonium reduction pathway) to maintain metabolic balance under Cu stress.

Horticulturae doi: 10.3390/horticulturae12050548

Authors: Xuezhen Yang Ming Chen Xiu Chen Qiaoli Ma Miaolian Xiang Tongqi Huang Ming Chen Zhuohua Li Xinxiang Meng Xichu Yu Jinyin Chen

Citrus bud mutants provide valuable genetic resources for breeding early-ripening cultivars with improved fruit quality. However, the physiological mechanisms underlying early ripening traits remain poorly understood. To elucidate the physiological basis for the early-ripening phenotype of the bud mutant ‘Longhuihong’ navel orange, fruit development was systematically monitored from 60 to 240 days after full bloom over two consecutive growing seasons, with the maternal cultivar ‘Newhall’ serving as a control. The results demonstrate that the precocity of ‘Longhuihong’ arises from the coordinated optimization of multiple fruit quality traits in this cultivar. The mutant exhibited enhanced fruit growth potential, with an average increase of 12.07–15.92% in single fruit weight. Peel coloration was significantly accelerated, as reflected by the faster coloring rate. Internal quality development followed a distinct pattern, characterized by high sugar accumulation, rapid acid degradation, and elevated vitamin C content. Notably, citric acid metabolism in ‘Longhuihong’ displayed a unique biphasic profile: substantial accumulation in the early stage, followed by rapid degradation in the later stage, which advanced the peak of the TSS/TA ratio by approximately 15 days. Principal component analysis further confirmed that the early ripening trait represents a systemic and integrated advancement in fruit size, sugar–acid balance, and peel pigmentation. Collectively, these findings provide a comprehensive understanding of the physiological mechanisms underlying precocity in ‘Longhuihong’ and offer key indices for breeding high-quality, early-ripening citrus cultivars.

Horticulturae doi: 10.3390/horticulturae12050547

Authors: Seolah Kim Yoon Jeong Jang Koeun Han Eun Su Lee Hong-Il Ahn Youngjae Oh Do-Sun Kim

Cultivated strawberry (Fragaria × ananassa) is an allo-octoploid for which the genetic basis of fruit appearance traits has not been comprehensively elucidated. This study investigated the genetic architecture of fruit color and morphological traits using integrated digital phenotyping and genome-wide association analysis of a core collection of diverse strawberry germplasm maintained for Korean breeding programs. A 108-accession core collection was assembled, genotyped, and phenotyped for 12 fruit quality traits. Population structure analysis identified K = 10 genetic clusters, and a Mantel test confirmed significant genotype–phenotype correspondence (r = 0.38, p < 0.001). Genome-wide association studies (GWAS) using BLINK and MLMM identified 15 significant marker–trait associations across six traits. Pleiotropic loci on chromosomes 15 (4C) and 22 (6B) were consistently associated with fruit lightness (L*) and red channel intensity (R) in both models, and the 6B locus explained approximately 18% of the phenotypic variance for each trait. Gene Ontology enrichment implicated transcriptional regulation, SUMOylation, and plastid-to-chromoplast transition, suggesting that the identified loci influenced fruit coloration through cellular regulatory mechanisms rather than direct pigment biosynthesis. These findings provide a genomic foundation for dual-trait marker-assisted selection targeting light and vividly red fruits for strawberry breeding.

Horticulturae doi: 10.3390/horticulturae12050545

Authors: Shujun Wang Guo Wang Fang Li Huanling Li Xiaoxu Li Yeyuan Chen Jiabao Wang

2,4-Dichlorophenoxyacetic acid (2,4-D) is a vital exogenous auxin for the induction and proliferation of litchi embryogenic callus. At present, its molecular regulation mechanism remains unclear. In this study, transcriptome sequencing samples were selected based on different cell growth phenotypes observed in ‘Feizixiao’ litchi embryogenic callus cultured in liquid medium with or without 2,4-D. By integrating transcriptome profiling with weighted gene co-expression network analysis (WGCNA), we identified key genes and signaling pathways dynamically responsive to 2,4-D concentration changes. We identified 558 commonly differentially expressed genes (DEGs), of which 117 were up-regulated and 387 were down-regulated; functional enrichment analysis revealed significant enrichment in the “plant hormone signal transduction” and “phenylpropanoid biosynthesis” pathways. In the former pathway, genes such as AUX28, GH3.17, GH3.6, and ARR5 were up-regulated; in the latter, by comparison, β-glucosidase 47 and Peroxidase 61 exhibited increased expression levels induced by 2,4-D. Furthermore, among these DEGs, 57 transcription factors belonged to 24 families. Notably, VRN1, FEZ, and DOF5.4 were significantly and rapidly induced by 2,4-D. WGCNA results demonstrated a significant positive correlation between the yellow module and 2,4-D treatment. Small heat shock protein (sHSP) genes constituted the core hub genes in the yellow module. Through Venn analysis of DEGs and key modules, 38 cross-genes were identified, of which non-specific lipid-transfer protein-like genes (nsLTP) were found to be specifically up-regulated without 2,4-D. The transcription factors and genes identified work in synergy to ensure the formation and sustained proliferation of embryogenic callus by precisely regulating the dynamic balance of auxin and cytokinin within cells and maintaining the stability of cell structure. Our findings provide a crucial theoretical foundation for understanding the molecular mechanism of 2,4-D in regulating litchi embryogenic callus proliferation.

Horticulturae doi: 10.3390/horticulturae12050546

Authors: Guanglian Liao Chunhui Huang Min Zhong Dongfeng Jia Limei Wang Xiaobiao Xu

Actinidia eriantha is an endemic kiwifruit species in China with high nutritional value and breeding potential. As a typical dioecious fruit tree, most currently bred cultivars are female, while the development of male pollinizer cultivars remains insufficiently studied and reported. Through long-term collection and evaluation of wild germplasm resources, our research team bred a male cultivar ‘Ganxiong 1’ with both ornamental and pollination value. In this study, the phenological traits, floral characteristics, major biological traits, ploidy levels, and genetic diversity of ‘Ganxiong 1’ were systematically analyzed and compared with those of the commonly used pollinizer ‘Moshan 4’. The results showed that ‘Ganxiong 1’ exhibited stable genetic traits, with branch bleeding occurring in late February and flowering in early May, highly overlapping with the flowering period of most female A. eriantha cultivars. It produced bright red flowers arranged in false dichasial cymes, showing high ornamental value. The average number of anthers per flower was 140.24, and the number of pollen grains per anther reached 8.57 × 104, with a pollen viability of 97.64% and a pollen tube length of 127.25 μm, indicating strong pollination potential. Ploidy and SSR analyses revealed that ‘Ganxiong 1’ is a diploid cultivar and is genetically distinct from previously reported A. eriantha cultivars at the DNA level. Regarding pollination effects, the fruit set rate, single fruit weight, seed number, SSC, and AsA content of ‘Ganlv 1’ fruits pollinated with ‘Ganxiong 1’ were significantly higher than those pollinated with ‘Moshan 4’, while the TA content was significantly lower than that of ‘Moshan 4’ pollination. In conclusion, ‘Ganxiong 1’ exhibits high stability and distinctiveness in phenological, morphological, cytological, and genetic characteristics. It can be considered a new ornamental and pollination dual-purpose cultivar of A. eriantha and provides an important parental resource for kiwifruit breeding programs.

Horticulturae doi: 10.3390/horticulturae12050544

Authors: Carmen Vega-Valdés Lucía Delgado-Salán Lucía Ruiz-Martos Pedro A. Casquero Antonio Ortiz Álvaro Rodríguez-González

Trypophloeus binodulus is a bark beetle present in mature poplar plantations that damages the bark of healthy trees and is currently expanding, posing a risk to these crops and impacting their economic profitability, since there is currently no early detection method or control strategy for this pest. This study was carried out in the province of León in three experimental plots affected by this pest, located in Villasabariego, Villoria de Órbigo, and Turcia to evaluate the effectiveness of different combinations of primary and secondary kairomonal compounds in different trap types. Moreover, the capture results obtained during 20 and 22 weeks in 2023 and 2024 years, respectively, of the field trial made it possible to determine that the most effective lure for monitoring and controlling T. binodulus is Ethanol + Salicylaldehyde, since its synergistic effect enhances its attractiveness. Also, the results confirmed that ESCOLITRAP® traps are the most effective under field conditions. These results identify an effective method for monitoring the pest, which could be a promising candidate for adoption by poplar growers, enabling progress toward sustainable management through semiochemical compounds.

Horticulturae doi: 10.3390/horticulturae12050543

Authors: Rouhan Qian Xiaohua Shi Xiaohui Wen Jianghua Zhou Keke Li Kaiyuan Zhu Huichun Liu

Paeonia lactiflora Pall. (herbaceous peony) is a high-value ornamental and medicinal plant in China with considerable market potential. However, conventional propagation methods are limited by low multiplication rates and long production cycles, making it difficult to meet the demand for large-scale planting materials. As a key approach for rapid propagation, tissue culture techniques for P. lactiflora have achieved significant progress in recent years. This review summarizes advances in the tissue culture system for P. lactiflora over the past decade, focusing on major in vitro regeneration pathways (organogenesis and somatic embryogenesis) and crucial technical stages, including explant selection and culture environment optimization. Distinct from previous reviews that only introduce partial technical aspects of P. lactiflora tissue culture, this review comprehensively outlines the overall tissue culture system, analyses the current species-specific bottlenecks (browning, vitrification, rooting and acclimatization) with their underlying causes and proposes targeted strategies. Furthermore, future development trends are prospected by integrating emerging research directions, including molecular regulatory mechanisms and eco-adaptive breeding. This review aims to provide a theoretical foundation and technical support for obtaining propagule for commercial plantations and achieving multi-functional utilization of P. lactiflora.

Horticulturae doi: 10.3390/horticulturae12050542

Authors: Deived Uilian de Carvalho Maria Aparecida da Cruz-Bejatto Ronan Carlos Colombo Inês Fumiko Ubukata Yada Rui Pereira Leite Junior Zuleide Hissano Tazima

Rootstock strongly influences citrus tree performance, but information remains limited for some regionally important cultivars. ‘IAPAR 73’, an early-season sweet orange commonly grown in Paraná, Brazil, has not been previously evaluated for rootstock responses. This study assessed the long-term effects of nine rootstocks, including ‘Rangpur’ lime, ‘Swingle’ citrumelo, ‘Volkamer’ lemon, ‘Caipira DAC’ and ‘Trifoliate’ oranges, ‘Cleopatra’ and ‘Sunki’ mandarins, ‘Carrizo’ and ‘Fepagro C-13’ citranges, on vegetative growth, yield, production stability, and fruit quality under Brazilian subtropical conditions. Tree growth was monitored annually for 10 years (2003–2013) and analyzed at establishment (5 years) and full production (10 years) phases of the orchard. Yield and fruit quality were evaluated across multiple harvests, and total soluble solids (TSS) stability was quantified using the coefficient of variation. Rootstock effects were analyzed using linear mixed-effects models in a randomized complete block design, considering rootstock and year as fixed effects and blocks as random effects. Rootstock significantly influenced all evaluated traits. ‘Carrizo’, ‘Cleopatra’, ‘Sunki’, and ‘Caipira DAC’ induced vigorous canopy growth and higher cumulative yields to the scion, while ‘Volkamer’ showed high yield efficiency and production stability. ‘Swingle’ and ‘Trifoliate’ enhanced TSS, TSS/TA ratios, and juice quality stability but induced lower vigor and yield, similar to ‘Rangpur’. This study provides the first evidence-based guidance for ‘IAPAR 73’ production, demonstrating that rootstock diversification can maximize productivity, stability, and sustainability in citrus orchards.

Horticulturae doi: 10.3390/horticulturae12050541

Authors: Salvador Emmanuel Sánchez-Cuapio Josefat Gregorio-Jorge Laura Jeannette García-Barrera Lilia Tapia-López José Luis Martínez y Pérez Erik Ocaranza-Sánchez

Despite the wide and accepted implementation of contemporary pharmaceutical medicine, the use of medicinal plants still prevails in several regions around the world, including Mexico. According to the World Health Organization (WHO), the use of incorrect species in natural and complementary medicine is a threat to consumer safety. Therefore, there is a need to characterize properly those plant species used in traditional medicine. In this study, a medicinal plant called Calanca, which is traded in the local market of a small community within the State of Puebla (Mexico), was characterized by different approaches. Conventional and molecular taxonomy analyses showed that Calanca belonged to the Asteraceae family, genus Chrysactinia. On one hand, molecular markers (rbcL, matK and ITS) helped to identify Calanca at the species level, being identified as C. mexicana. On the other hand, although not used for molecular taxonomy, additional gene markers were amplified and submitted to the GenBank database to expand the toolkit for C. mexicana identification. In addition, soil taxonomy and quantitative chemical analyses provided insights into the relationship between growing conditions and the chemical compounds produced by C. mexicana. Chemical compounds associated with medicinal properties such as phenolic acids, flavonoids, terpenes, and anthocyanins were identified in C. mexicana extracts. Finally, greenhouse conditions for the cultivation of this species were also investigated. Overall, this comprehensive characterization provides the essential botanical and chemical foundation required for future toxicological and clinical safety assessments, while establishing a robust framework for the long-term conservation of this endangered medicinal resource.

Horticulturae doi: 10.3390/horticulturae12050540

Authors: Haoran Wang Ping Li Ying Han Xinxin Yin Huanhuan Yang Jingbin Jiang

To clarify the regulatory mechanism of NLA on tomato plant architecture and fruit quality, wild-type (WT), nla mutant (narrow leaf angle), and NLA overexpression lines (OE1, OE2) were used as materials, and the study was carried out through genetic analysis, phenotypic and quality determination, and gene expression analysis. The results showed that the tomato leaf angle is controlled by a single gene with semi-dominant inheritance. The nla mutant forms a compact plant architecture due to reduced cell volume at the leaf angle. During vegetative growth, it exhibited significantly increased plant height and decreased stem diameter and crown width. During reproductive growth, it showed significantly higher height of the first inflorescence node and a significantly higher number of the first flowering node. The nla mutant maintained a higher SPAD value during the whole growth period. Mutation of NLA had no significant effect on soluble solids content, but significantly increased flavonoid and titratable acid contents. Meanwhile, the compact architecture optimizes plant spatial distribution, and higher flavonoid content improves antioxidant capacity. Molecular mechanism analysis combined with GA quantification showed that the nla mutant exhibited significantly higher contents of bioactive GA1 and GA4, which were closely associated with up-regulated expression of GA biosynthetic genes SlGA20ox1 and SlGA20ox2, as well as down-regulated expression of GA catabolic genes SlGA2ox4 and SlGID1.This study provides a theoretical basis for high-photosynthetic-efficiency breeding and high-quality cultivation of tomato.

Horticulturae doi: 10.3390/horticulturae12050539

Authors: Peisen Tang Huanhuan Niu Shixiang Duan Yaomiao Guo Qishuai Kang Xiaojiu Liu Yachen Liu Shibo Peng Weige Yuan Mengyuan Yan Huayu Zhu Dongming Liu Wenkai Yan Jianbin Hu Luming Yang Junling Dou Junyi Tan

Plant architecture is a critical agronomic trait in watermelon (Citrullus lanatus), with vine length directly influencing planting density, light interception, and field management efficiency. Short-vine forms have become important agronomic targets in breeding due to their advantages of high-density planting, efficient light utilization, and simplified field management. In this study, a dwarf mutant, designated PKH207, was identified from an ethyl methanesulfonate (EMS)-mutagenized population of the watermelon inbred line G42. The mutant exhibited significantly reduced plant height and shortened internodes due to decreased cell expansion in stem tissues. Genetic analysis indicated that the dwarf phenotype in PKH207 is controlled by a single recessive gene, which was named Cldw2 (Citrullus lanatus dwarf mutant 2). Using a population of 558 F2 plants, bulked segregant analysis sequencing (BSA-seq) and linkage mapping delimited the causal locus to a 540.6 kb region on chromosome 10. Within this interval, a single-nucleotide polymorphism (SNP) mutation was identified in the gene ClG42_10g0100600, encoding an α-tubulin, and this gene was determined to be the candidate gene for the dwarf phenotype. Transcriptome analysis revealed that this mutation significantly disrupts key biological processes, including cell wall biosynthesis, microtubule cytoskeleton organization, and auxin signaling pathways, contributing to the dwarfism phenotype. This study identifies a novel dwarfing allele in cucurbits and provides a direct molecular target for breeding compact watermelon cultivars suited to high-density production.

Horticulturae doi: 10.3390/horticulturae12050538

Authors: Amine Guesmi Michele Antonio Savoia Faten Zaouay Sameh Rahmani Mnasri Francesco Luigi Aurelio Aziz Akkak Cinzia Montemurro Messaoud Mars Monica Marilena Miazzi Olfa Saddoud Debbabi

The use of fresh and dried figs has increased markedly in Tunisia in recent years, leading to a rise in public subsidies to support the further development of fig cultivation, especially in well-adapted production areas and with the adoption of innovative agronomic practices. This study aimed to carry out a comprehensive morphological and genetic characterization of fig germplasm from the Kesra region in north-western Tunisia, which is widely recognized for its long-standing tradition of fig production, in particular of the ‘Zidi’ cultivar. Field surveys and prospections enabled the identification of 26 distinct local fig cultivars, which were morphologically characterized and genotyped using 12 microsatellite (SSR) markers. All cultivars showed a specific allelic profile, including ‘Zidi’. The results provided valuable information for the conservation and management of Tunisian fig genetic resources. Moreover, the data will support the valorization of local fig production in the area through the establishment of the Protected Designation of Origin (PDO) ‘Fig of Kesra’, thereby contributing to the sustainable development of traditional orchards and the preservation of local agrobiodiversity.

Horticulturae doi: 10.3390/horticulturae12050537

Authors: Dong Li Qizan Hu Xuena Yu Longda Wang Jiaxin Li Bo Sun Yanting Zhao Meilan Li

Brassica juncea exhibits diverse foliar pigmentation patterns caused by anthocyanin accumulation, but the molecular basis of margin-specific pigmentation remains unclear. Here, we combined anthocyanin measurement, comparative transcriptomics, and functional analysis of BjMYB113 to investigate anthocyanin spatial distribution in mustard. The data showed that anthocyanin content was significantly higher in the leaf margin (LM) than in the leaf interior (LI) of the bicolored accession ZD30. Transcriptome analysis identified 618 DEGs between LM and LI in ZD30, compared with only 134 DEGs in the uniformly purple accession JCS53. Enrichment analyses indicated that ZD30-specific DEGs were mainly involved in flavonoid metabolism, anthocyanin biosynthesis, and secondary metabolism. Expression profiles of genes involved in anthocyanin biosynthesis indicated that BjMYB113 and BjTT8 were more highly expressed in the pigmented margin of ZD30, together with key late biosynthetic genes (DFR, ANS, and UFGT) and GSTF. In addition, transient overexpression of BjMYB113 promoted anthocyanin accumulation in leaves, suggesting that BjMYB113 acts as a positive regulator of anthocyanin accumulation and supporting a putative model in which localized activation of anthocyanin-related genes contributes to margin-specific pigmentation in B. juncea. This study provides insight into the transcriptional regulation of anthocyanin spatial distribution in mustard.

Horticulturae doi: 10.3390/horticulturae12050536

Authors: Tingting Zhou Yueping Zeng Lihui Jiang Yanbi Wu Deqi Liu Lang Jiang Yiqing Liu Xuemei Zhang

Soil salinity limits ginger productivity, but the underlying molecular mechanisms remain largely unclear. The 14-3-3 proteins are conserved regulators in stress signaling. Here, we genome-wide characterized the 14-3-3 family in Zingiber officinale and examined the possible involvement of Zo14-3-3-03 in salt response. A total of 21 Zo14-3-3 genes were identified and classified into four groups with uneven chromosomal distribution. Among them, Zo14-3-3-03 was strongly salt-responsive: transcript levels increased 9.91- to 33.82-fold during 1–7 days of treatment and reached 62.47-fold in leaves at day 14. NaCl treatment elevated GUS expression driven by the Zo14-3-3-03 promoter. Virus-induced gene silencing (VIGS) of Zo14-3-3-03 resulted in silenced plants exhibiting higher malondialdehyde (up to 73.6%), lower antioxidant enzyme activities (SOD, POD, CAT, and APX: 18.9–31.9% reduction), reduced osmolytes (proline, soluble protein, sugars, and ascorbic acid: 23.2–36.2% reduction), excessive reactive oxygen species, and decreased relative water content. Several antioxidant-related genes were significantly downregulated. Protein interaction assays suggested a possible interaction with ZoSOS2, and the expression of SOS2 pathway genes was altered in silenced plants, indicating a potential link to calcium signaling and ion homeostasis. Taken together, these results suggest that Zo14-3-3-03 participates in ginger salt stress response possibly through redox balance, osmotic adjustment, and calcium-mediated pathways which would provide a basis for understanding 14-3-3-mediated stress responses and nominates Zo14-3-3-03 as a candidate requiring deeper validation for salt tolerance improvement in ginger. Nevertheless, due to limited functional validation, its role as a positive regulator and breeding target remains preliminary. Further genetic and mechanistic studies are needed to confirm causality and assess field-level applicability.

Horticulturae doi: 10.3390/horticulturae12050535

Authors: Xiyuan Li Jinmei Ge Peiyuan Sun Hongji Zhang Jing Wang Ruimei Wang Yuezhen Li Yi Zhao Rong Wang Chongde Wang Huijie Wang Liguang Huo Yun Zheng Decai Yu

Potato early blight (EB), caused by Alternaria, is an economically devastating fungal disease affecting global potato production. Using a hybrid population derived from distantly related varieties, we combined resistance evaluation, histological analysis, Bulked Segregant Analysis sequencing, RNA sequencing and molecular dynamics simulation, which successfully identified key candidate resistance genes. Genetic mapping localized three major resistance-associated regions on chromosome 8 spanning positions 25.07–29.20 Mb, 38.05–38.80 Mb, and 39.40–40.78 Mb. Through candidate gene analysis, we identified CND41, encoding an aspartic protease, as the prime candidate. This gene exhibited significantly higher basal expression levels and stronger pathogen-induced upregulation in resistant genotypes. Molecular dynamics simulations further identified six crucial non-synonymous mutations in the TAXI-N domain that likely contribute to enhanced resistance by destabilizing the susceptibility-associated protein conformation. Transient overexpression of CND41 provided functional evidence supporting its likely involvement in early blight resistance (EBR). These findings contribute valuable genetic resources and a strong candidate gene for molecular breeding toward EBR potato varieties.

Horticulturae doi: 10.3390/horticulturae12050534

Authors: Sihem Amri Rima Hind Boudchicha Sakina Bechkri Fethia Zadri Seloua Bellara Ali Boumegoura Douadi Khelifi

This study presents a genetic characterization and population structure analysis of an ancient Algerian collection of Citrus fruits, dating back to the colonial period of the early 1900s. Genetic diversity was assessed using eight Simple Sequence Repeat (SSR) markers, with the objective of accurately identifying their varieties and elucidating their genetic relationships, particularly in the absence of passport data and documented origins. A total of 96 accessions were analyzed. Instances of homonymy, synonymy, and labeling errors were detected. Observed heterozygosity ranged from 0.451 to 0.715, with a mean value of 0.54, while polymorphic information content (PIC) values varied between 0.225 (CCSM18) and 0.635 (TAA41). The genetic relationship patterns among the different Citrus groups were consistent with their botanical classification. Structureanalysis suggested differentiation between the pomelo–orange cluster and the lemon group, as well as between the mandarin and clementine groups. These results suggest thatAlgerian Citrus germplasm may represent a valuable and relatively underexplored resource for breeding programs, highlighting the importance of its proper characterization and conservation to prevent genetic erosion.

Horticulturae doi: 10.3390/horticulturae12050533

Authors: Akvilė Viršilė Gediminas Kudirka Kristina Laužikė Audrius Pukalskas Giedrė Samuolienė

Artificial lighting is a central and resource-intensive component of controlled environment agriculture, directly regulating plant physiological processes while influencing energy efficiency and production outcomes. Chlorophyll fluorescence analysis, particularly pulse-amplitude-modulated fluorometry, provides a rapid and non-destructive method for assessing plants’ photosynthetic efficiency. However, the extent to which chlorophyll fluorescence reflects plant responses to different light spectra across species remains insufficiently understood. In this study, species-specific photoresponses of leafy vegetables (Amaranthus tricolor, Barbarea verna, Chrysanthemum coronarium, Perilla frutescens) to different light spectra were investigated by integrating chlorophyll fluorescence with growth, antioxidant, and pigment traits. Plants were cultivated under monochromatic red, blue, and combined red–blue light, with additional far-red supplementation. Correlation analysis was performed among growth, antioxidant parameters, pigment contents, and chlorophyll fluorescence parameters. The obtained results show that chlorophyll fluorescence parameters respond selectively, but species-specifically, to applied lighting-spectrum conditions. Relationships between fluorescence indices and physiological traits varied between species, and no single parameter consistently reflected plant performance across all crops. Therefore, to employ chlorophyll fluorescence as a useful proxy for assessing plant responses to lighting spectrum, a species-specific and context-dependent approach is required.

Horticulturae doi: 10.3390/horticulturae12050532

Authors: Linsen Yan Mingyang Wang Chenglong Yu Pengxue Jia Xintong Gao Enduo Liu Zhongping Chai

The impact of potassium fertilization on disease resistance in Korla fragrant pear trees was evaluated under drip irrigation to determine the optimal application rate. Seven- to eight-year-old trees were subjected to four K treatments: the control (K0, 0 kg/hm) and applications of 75 (K75), 150 (K150), and 225 kg/hm2 (K225). Disease resistance indices in current-year shoots and old branches were assessed throughout growth stages, and correlations with branch mineral contents were analyzed. The K75 treatment significantly increased branch Ca and Mg contents and enhanced flavonoid and lignin contents and PAL activity relative to K0. The K150 treatment markedly raised N, P, K, Fe, Mn, and Cu contents, as well as flavonoid, lignin, soluble sugar, PPO, and PAL levels, with optimal effects on flavonoids and old branch PAL activity. The K225 treatment mildly reduced Ca and Mg but strongly elevated total phenols, flavonoids, lignin, soluble sugars, PPO, and PAL, exerting the greatest influence on total phenols, soluble sugars, PPO, and current-year shoot PAL. K rates were significantly correlated with disease resistance indices. Branch mineral contents showed highly significant correlations with resistance indices and yield, but resistance indices were not significantly associated with yield. Potassium directly modulated resistance indices, with mineral elements exerting more pronounced effects in current-year shoots. Application of 150 kg/hm K is proposed as the optimal rate to improve disease resistance, mineral nutrition, tree vigor, survival, and yield in 7–8-year-old Korla fragrant pear orchards.

Horticulturae doi: 10.3390/horticulturae12050531

Authors: Wei Hong Kaiyue Wu Jun Tian Yan Bai Changhong Guo Yongjun Shu

Gene family expansion and contraction are key processes underlying functional innovation and genome evolution in plants, yet their roles in the horticultural plant white clover (Trifolium repens) remain poorly understood. In this study, we systematically investigated the association between lineage-specific whole-genome duplication (WGD) and short interspersed nuclear elements (SINEs) with gene family dynamics and stress-responsive transcription. Our results indicate that white clover underwent a lineage-specific WGD, which is associated with increased gene family expansion. SINE copy number was strongly correlated with the proportion of significantly expanded genes (r = 0.637, p = 0.0259, n = 12), but not with the proportion of significantly contracted genes. This result suggests a potential association between SINE insertions and gene family expansion. GO enrichment analyses indicated that expanded gene families are predominantly involved in metabolic processes, environmental stress responses, defense mechanisms, and floral organ development, whereas contracted gene families were mainly enriched in core housekeeping functions, such as ubiquitin-dependent protein catabolism and mitochondrial organization. Transcriptome analyses further showed that genes within expanded families were broadly upregulated under drought, cadmium, and cold stress, while generally upregulated in floral tissues compared with other organs. Collectively, these findings reveal the relationships among WGD, SINE elements, and gene family dynamics in environmental adaptation and flower development, providing a molecular framework for understanding adaptive regulation associated with gene family expansion.

Horticulturae doi: 10.3390/horticulturae12050530

Authors: Akshay Radha Mohan Sharma Narendra Singh Nimisha Sharma Om Prakash Awasthi Shruti Sethi Virendra Singh Rana Shailendra Kumar Jha Vinod Kumar Sharma Mukesh Shivran Hatkari Vittal Abeer Ali Anil Kumar Dubey

The influence of rootstocks on mineral nutrient composition in the edible tissue of citrus fruits has not been explored so far. This study assessed leaf and juice mineral nutrients of sweet orange (Citrus sinensis (L.) Osbeck) cultivars (‘Pusa Sharad’ and ‘Pusa Round’) grafted onto different rootstocks (‘RLC-6’, ‘C-35’, ‘X-639’, ‘Yamma Mikan’, ‘Soh Sarkar’, ‘RLC-7’, and ‘Jatti Khatti’). Deviation from optimum percentage (DOP) index was employed as an integrative measure to assess leaf mineral nutrient balance for specific scion–rootstock combinations. The relative abundance of leaf mineral nutrients was ranked as follows: Ca > K > P > S > Mg > Na > Fe > Mn > Zn > Cu. Overall, rootstock ‘X-639’ demonstrated superior mineral nutrient uptake efficiency across grafted plants of both scion cultivars, as indicated by higher leaf mineral nutrient concentrations. Juice mineral nutrient concentrations followed the order K (930.87–1362.17 mg L−1), Ca (346.40–651.33 mg L−1), P (116.23–236.97 mg L−1), Mg (64.60–102.50 mg L−1), S (49.35–74.34 mg L−1), Na (25.61–47.88 mg L−1), Fe (4.76–7.92 mg L−1), Zn (1.79–4.34 mg L−1), Mn (0.73–1.62 mg L−1), and Cu (0.41–0.71 mg L−1), indicating distinct differences in the accumulation pattern of macro- and micro-mineral nutrients in the edible tissues across the studied scion–rootstock combinations. Multivariate analysis revealed that the rootstocks significantly influenced juice mineral nutrient levels, indicating rootstock-mediated agronomic biofortification. Rootstock ‘RLC-6’ enhanced juice K levels, and ‘Soh Sarkar’ improved juice Mg contents, while ‘X-639’ improved juice micronutrient (Zn, Mn, Cu) accumulation in both cultivars. This study constitutes the first comprehensive investigation that explicitly evaluates the influence of rootstocks on the enhancement of mineral nutrient content in the edible tissues of citrus fruits. It further elucidates how rootstock selection can indirectly affect dietary mineral intake, thereby highlighting its potential role for improved nutrition.

Horticulturae doi: 10.3390/horticulturae12050529

Authors: Giuseppa Rosaria Leonardi Alexandros Mosca Daniele Nicotra Maria Elena Massimino Giulio Dimaria Grete Francesca Privitera Alessandro Vitale Giancarlo Polizzi Dalia Aiello Vittoria Catara

Microbial communities associated with the rhizosphere and phyllosphere are recognized as fundamental components influencing essential plant processes, including nutrient acquisition, growth promotion, and tolerance to stress. Biological control agents (BCAs), such as Trichoderma spp. and Bacillus spp., are widely applied in citrus crops. However, while BCAs effectiveness against plant pathogens is widely established, their resulting impact on indigenous, non-target bacterial and fungal communities remains poorly understood. The aim of this study was to evaluate the non-target effects of two commercial microbial formulations—one containing Trichoderma asperellum ICC 012 and T. gamsii ICC 080, and the other Bacillus amyloliquefaciens QST 713—on the resident microbiomes of Citrus volkameriana seedlings by using the amplicon-based metagenomic analysis, targeting the 16S rRNA and ITS1 regions. The application of the Trichoderma formulation as a soil drench in the rhizosphere resulted in minimal changes to the overall composition and diversity (α- and β-diversity) of the bacterial communities. This stability is considered a desirable trait for overall soil health. However, specific taxonomic changes were observed, such as a notable decrease in the genus Rhodococcus (0.4% vs. 1.5% in controls) among bacteria. In the fungal communities, the treatment led to a significant shift in phylum relative abundance, characterized by an increase in Basidiomycota (38% vs. 28% in controls) and a corresponding decrease in Ascomycota (51% vs. 56% in controls). Successful colonization was confirmed by a substantially higher relative abundance of the inoculated Trichoderma genus compared to control plants (1.4% vs. 0.1% in controls). Conversely, the foliar application of the Bacillus product induced a substantial restructuring of the phyllosphere bacterial community. This treatment caused a statistically significant reduction in bacterial α-diversity and a clear differentiation in community composition (β-diversity) relative to untreated controls. The successful colonization by the BCA resulted in the dominance of the Bacillus genus in the treated samples (27% vs. 2% in controls). Importantly, this ecological shift was accompanied by the enrichment of other beneficial bacterial taxa, including Sphingomonas (15% vs. 4% in controls) and the Burkholderia-Caballeronia-Paraburkholderia group (4% vs. 2% in controls). While fungal phyla abundances remained generally stable in the phyllosphere, specific genera such as Cladosporium (15% vs. 23% in controls) and Symmetrospora (21% vs. 13% in controls) prevailed post-treatment. In conclusion, these findings highlight the importance of considering non-target microbiome shift when implementing microbial biocontrol strategies in citrus production systems, since in this study was demonstrated that commercial BCAs exert a markedly differential influence based on the compartment of application: Trichoderma promoted ecological stability in the rhizosphere, whereas Bacillus induced a directional community shift in the phyllosphere.

Horticulturae doi: 10.3390/horticulturae12050528

Authors: Juan Daniel Moreno-Olivares Mar Vilanova María José Giménez-Bañón José Cayetano Gómez-Martínez Rocío Gil-Muñoz

This study aimed to evaluate the aromatic potential of four new Monastrell-derived white grapevine genotypes (MC180, MC69, MT103, MV67) compared with Verdejo over four consecutive seasons (2020–2023), with particular emphasis on both free and glycosidically bound volatile compounds. This approach provided novel insight into the aromatic composition of emerging cultivars under warm climate conditions and their potential suitability for future viticultural use. Free and glycosidically bound volatile compounds were extracted and analyzed using Gas Chromatography–Mass Spectrometry (GC-MS). Differences in aroma profiles were observed among genotypes and seasons. MV67 and MC69 showed higher levels of monoterpenes and volatile phenols, suggesting enhanced floral and complex aromatic potential. Seasonal effects strongly influenced C6 compounds and norisoprenoids, highlighting the importance of climatic conditions in shaping grape aroma. Multifactorial analysis revealed that season had the greatest impact on most compound families, although genotype and its interaction with season were also significant. These results demonstrate that genotype–environment interactions play a key role in determining aromatic composition. The elevated levels of aroma precursors, particularly glycosidically bound compounds, indicate promising enological potential for producing fresh, aromatic white wines. Therefore, these new cultivars represent suitable alternatives for white wine production in warm climates.

Horticulturae doi: 10.3390/horticulturae12050526

Authors: Giuliano Bonanomi Mohamed Idbella Alessia Cozzolino Giandomenico Amoroso Maurizio Zotti Riccardo Motti Giuseppina Iacomino

Weed infestations are a major agricultural problem, driving the need for sustainable control methods beyond conventional synthetic herbicides. This study explored wood vinegar (WV), a pyrolysis by-product, as a dual-purpose tool for weed management and crop growth. Chemically characterized WV exhibited an acidic pH, high acetic acid content, and diverse organic compounds. Pot experiments demonstrated WV’s strong, concentration-dependent inhibition of weed seedling emergence. Field trials across three seasons confirmed WV’s efficacy in reducing weed density and biomass, particularly at 50% and 100% concentrations, while also influencing weed community composition. Critically, subsequent evaluation of residual phytotoxicity on tomato and courgette crops revealed that WV 50% significantly optimized both plant biomass and fruit yield. In contrast, WV 100% negatively impacted courgette yield, and WV 10% showed variable effects. These findings highlight WV, especially at optimal dilutions like 50%, as a promising sustainable solution for integrated weed management with potential biostimulant properties for crops.

Horticulturae doi: 10.3390/horticulturae12050527

Authors: Orsolya Papp Nuri Nurlaila Setiawan Katalin Allacherné Szépkuthy Flóra Pászti-Milibák Attila Ombódi Ilona Kaponyás Ferenc Tóth Dóra Drexler

Optimizing nutrient management in organic polytunnel production remains challenging due to the limited availability of field-based knowledge on the mineralization dynamics of organic fertilizers. At the same time, microalgae-based products such as Chlorella vulgaris have gained increasing attention in recent research, yet their interactions with nutrient supply intensity are not well understood. This study aimed to evaluate the effects of increasing nutrient supply intensities (34, 116, and 189 kg ha−1 N from different organic sources), in combination with C. vulgaris foliar application, on the crop performance of kapia pepper and a subsequent leafy green crop under on-farm organic polytunnel conditions on soil with moderate organic matter content. Increasing production intensity did not result in significant improvements in pepper yield or vegetative biomass (p > 0.05), and no significant residual effects of nutrient supply were detected in the yield of the subsequent leafy green crop (p: 0.08–0.94). C. vulgaris treatment showed predominantly non-significant but positive trends in several parameters, but only in combination with high-intensity technology, while reducing the total pest damage of the thrips and stinkbug index up to 15.7% in most technology variations. These results indicate that the effects of C. vulgaris may be strongly context-dependent and confirm that increasing the intensity of nutrient supply may carry the risks of conventionalization of organic farming practices.

Horticulturae doi: 10.3390/horticulturae12050525

Authors: Angela María Castaño-Marín Gerardo Antonio Góez-Vinasco Paola Andrea Hormaza-Martínez Lucas Esteban Cano-Gallego Luis Felipe López-Hernández Jaime Darío Posada-Rua Carolina Zuluaga-Mejía Cristian Domínguez-Pulgarín Valentina García-Valencia Juan Camilo Henao Rojas

Understanding of carrot growth dynamics and ecophysiological functioning in tropical highland environments remains limited, despite the crop’s productive importance in the Colombian Andean region. This study aimed to characterize biomass accumulation and partitioning, as well as the photosynthetic response to radiation, in two carrot (Daucus carota L.) cultivars (Berlicum- and Flakkee-type) grown under high-altitude Andean tropical conditions in Rionegro, Antioquia. To account for field spatial heterogeneity, four beds were used as blocks, and both cultivars were evaluated in parallel under comparable field conditions. Weekly destructive samplings were performed to quantify total dry biomass, shoot biomass, root biomass, leaf number, and leaf area. In addition, the response of net CO2 assimilation to photosynthetically active radiation was evaluated using a portable gas-exchange system. Total and root biomass were described using logistic models, shoot biomass using a Gaussian model, and the photosynthetic response using an exponential model. Berlicum showed higher biomass accumulation, whereas Flakkee exhibited an earlier response of growth and photosynthetic activity. In both cultivars, the highest functional capacity was concentrated in stage III, coinciding with the strengthening of the storage-root sink. Overall, the results indicate contrasting temporal patterns in biomass partitioning and photosynthetic performance between the two carrot cultivars and provide a useful ecophysiological framework for interpreting crop management and harvest timing under high-altitude Andean tropical conditions.

Horticulturae doi: 10.3390/horticulturae12050523

Authors: Lucia Giordano Luca Pallotti Vania Lanari Oriana Silvestroni Julian Garcia Berrios Alberto Palliotti

The protection of leaves from photoinhibition and berries from dehydration and sunburn has become an increasingly important objective in response to the rising frequency and intensity of heat waves worldwide. This research investigated the effect of a white nonwoven geotextile sheet (TNT) installed in the fruiting zone in the white cultivar ‘Verdicchio’ (Vitis vinifera L.) during critical summer periods with the aim of protecting leaves and berries from extreme heat. The study was conducted over two seasons (2020–2021) in a rainfed vineyard in central Italy using a randomized block design. Physiological and yield parameters were recorded. Vines protected with TNT did not show any changes in net photosynthesis, stomatal conductance, and water use efficiency, compared to unshielded vines. However, TNT reduced leaf temperature and increased berry total acidity and malic acid concentration while reducing sugar content, leading to wines with higher freshness and reduced alcohol levels. The use of TNTs shows significant potential as a practical tool for viticulturists to mitigate the effects of excessive heat, allowing for better management of berry ripening and ultimately improving final wine characteristics. Additionally, TNT is economically feasible, especially if applied only to the afternoon-exposed side of the canopy, and its cost can be amortized, especially in vineyards affected by frequent heat waves and/or dedicated to the production of premium wines.

Horticulturae doi: 10.3390/horticulturae12050524

Authors: Jinhui Lin Xin Feng Ting Chen Xinming Liu Yaohui Jiang Haichao Gong Jinghao Huang Yan Lei

Grapes are among the most widely cultivated fruit crops globally, yet their growth and yield are severely compromised by Colletotrichum viniferum, which causes a devastating disease that affects grape berries. The wall-associated kinase (WAK) gene family, a unique subfamily of receptor-like-kinases (RLKs), plays important roles in mediating plant responses to both abiotic and biotic stresses. However, the expression patterns and biological functions of grape WAKs in response to C. viniferum infection remain largely uncharacterized. In this study, a total of 57 VdWAK genes were identified and phylogenetically classified into twelve subgroups. Chromosomal localization and collinearity analyses further revealed that tandem duplication and segmental duplication events contributed to the expansion of the VdWAK gene family. Transcriptomic profiling identified VdWAK19 as a key responsive gene. It was predominantly expressed in mature berries but transcriptionally repressed upon C. viniferum infection. Virus-induced gene silencing assays in grape berries demonstrated that knockdown of VdWAK19 significantly reduced fruit resistance to C. viniferum infection. Overall, these findings advance our understanding of the functional roles of VdWAK genes during C. viniferum infection and provide a theoretical basis for the potential application of VdWAK19 in breeding grape varieties with enhanced resistance to ripe rot.

Horticulturae doi: 10.3390/horticulturae12050522

Authors: Suzy Y. Rogiers Jean T. Page Manisha Thapa Kwanho Jeong Terry J. Rose

This study quantified nutrient accumulation and partitioning among the kernel, shell, husk, rachis, and leaves during fruit development in three macadamia cultivars. Racemes and leaves were sampled at biweekly intervals until kernel maturity. The shell and rachis ceased to accumulate biomass earlier in the season than the husk or kernel. Nitrogen (N) and potassium (K) were the dominant nutrients accumulated in the fruit. Despite declining concentrations between 80 and 140 DAF, total kernel nutrient content continued to increase, indicating sustained nutrient import during this critical period. The kernel was the primary sink for N, phosphorus (P), sulfur (S), and magnesium (Mg), with peak accumulation occurring during rapid kernel growth at 80–175 days after flowering (DAF). In contrast, the accumulation of calcium (Ca) and manganese (Mn) into the kernel ceased earlier, suggesting limited late-stage mobility. The husk accumulated more K than the kernel and remained an active sink for K, S, Mg, Ca, and Mn until maturity, while N, P, and boron (B) accumulation slowed after ~107 DAF. The shell contributed minimally to nutrient demand, with N, zinc (Zn), and B accumulation ceasing after shell hardening (90–110 DAF). The cultivars exhibited consistent temporal patterns, differing mainly in magnitude. Nutrient partitioning efficiency among- the fruit components was highest for cv. A38. The rachis acted as a transient sink early in development before declining in mobile nutrients, while leaf nutrient dynamics did not reflect fruit demand.

Horticulturae doi: 10.3390/horticulturae12050521

Authors: Die Hu Lu Yang Yi Zhu Xiaohu Chen Yongjun Fei

Oil and gas drilling waste drilling fluid is a complex alkaline mixture that poses risks to plants and soil ecosystems during transportation and disposal due to potential leakage. This study investigates the effects of waste drilling fluid on the growth of Trifolium pratense (L.) and Astragalus sinicus (L.) and on the soil ecosystem, aiming to provide a theoretical reference for ecological restoration of oil and gas field sites. Four gradients of waste drilling fluid stress were established by mixing 0, 50, 100, and 150 mL of waste drilling fluid into the substrate, with 0 mL serving as the control. Seed germination, morphological development, physiological, and biochemical indices of the two leguminous plants, as well as soil nutrients and enzyme activities, were analyzed, followed by a comprehensive evaluation. Waste drilling fluid stress inhibited the growth of both leguminous plants. Their physiological and biochemical parameters, such as antioxidant enzyme activities and osmotic regulatory substances, exhibited a gradually increasing trend with increasing waste drilling fluid concentration. Concurrently, waste drilling fluid stress reduced soil nutrient availability and decreased soil enzyme activities. Notably, soil nutrient content increased after planting compared to the original soil without plants. Planting these two leguminous plants can effectively alleviate the negative impacts of waste drilling fluid stress, thereby indirectly contributing to soil remediation.

Horticulturae doi: 10.3390/horticulturae12050520

Authors: Xiaoxi Liu Ming He Yangyi Zheng Jianning Luo Junxing Li Hao Gong Haibin Wu Gangjun Zhao Liting Deng Xueting Wang Chengcheng Feng Xiaoming Zheng

The first female flower node (FFFN) is a crucial trait affecting earliness and yield in bitter gourd (Momordica charantia L.). To identify the genetic locus and candidate gene controlling FFFN, we performed phenotypic and genetic analyses using two parental lines, ‘M144’ (average FFFN: 6.3 ± 2.0) and ‘K55’ (average FFFN: 22.0 ± 4.5), along with their F1 hybrid and an F2 population consisting of 317 individuals. The results show that the low FFFN trait was incompletely dominant over the high FFFN trait. Using BSA-seq, we mapped a FFFN locus to an interval of 18.8–22.5 Mb on chromosome 4. Fine mapping with KASP markers narrowed the McFFFN4.1 to a 73.05 kb interval between markers 25QP334 and 26QP20, which contained seven predicted genes. Transcriptome analysis revealed that only Moc04g29650, which is annotated as cytochrome b-c1 complex subunit Rieske, was differentially expressed between the parents within this mapping interval. Sequence comparison identified a single SNP (C > A) in the promoter region of Moc04g29650, which was located within a putative YAB1/FIL-binding motif. Given the known role of FILAMENTOUS FLOWER (FIL) in regulating floral transition in Arabidopsis thaliana, Moc04g29650 is proposed as the most likely candidate gene for McFFFN4.1. The KASP marker 26QP20, located near Moc04g29650, showed the strongest association with FFFN in the F2 population, with a maximum LOD score of 5.45, and thus represents a valuable tool for marker-assisted selection (MAS) breeding in bitter gourd. This study lays a foundation for cloning McFFFN4.1 and genetically improving early maturity in bitter gourd.

Horticulturae doi: 10.3390/horticulturae12050519

Authors: Javed Iqbal Abdul Basit Chengyue Li Runru Liu Youhuan Li Suchan Lao Dongliang Qiu

Fruit anthocyanins are primary determinants of color, sensory quality, and nutritional value in grapes; however, their endogenous biosynthesis is governed by complex interactions among genetic, environmental, agronomic, and postharvest factors. This review elaborates recent advances in physiology and molecular biology to clarify the biosynthetic mechanisms in grapes, including the coordinated action of structural enzymes, MYB–bHLH–WD40 regulatory complexes, hormone-mediated signaling pathways, and vacuolar transport processes. Key environmental factors, such as temperature fluctuations, light exposure, water availability, and soil properties, regulate these networks, contributing to significant variation in pigmentation profiles across cultivars and growing regions. Strategic agronomic practices, including canopy management, regulated deficit irrigation, balanced nutrient management, and temperature-mitigation techniques, further influence pigmentation by modifying the microclimate of the fruit zone during development. Based on these mechanistic insights, this review evaluates targeted strategies for enhancing anthocyanin accumulation, highlighting recent progress in genetic improvement through CRISPR/Cas genome editing, transgenic approaches, and marker-assisted selection (MAS), which enable precise modulation of biosynthetic and regulatory genes. Complementary postharvest interventions, such as optimized cold storage, modified-atmosphere packaging, hormonal elicitors, and controlled oxidative technologies, provide additional opportunities to maintain or enhance pigment stability after harvest. Collectively, these advances establish a comprehensive framework linking molecular regulation with practical vineyard, breeding, and postharvest strategies, offering an integrated pathway to improve anthocyanin consistency, berry quality, and the phenolic characteristics of grape-derived products.

Horticulturae doi: 10.3390/horticulturae12050518

Authors: Boyin Qiu Qianrong Zhang Hui Lin Jianting Liu Zuliang Li Changhui Bai Qingfang Wen Dazhong Li Haisheng Zhu

Fruit flesh thickness is one of the key factors affecting the yield and quality of bitter melon, and its regulatory mechanisms remain unclear. One thick-flesh germplasm (KF) and one thin-flesh germplasm (NF) with significantly different flesh thicknesses were screened from 70 bitter melon germplasms. Through phenotypic surveys, combined metabolomic and transcriptomic analyses, and exogenous sugar treatments, the regulatory mechanisms on flesh thickness were preliminary investigated. The results showed that flesh thickness of the two germplasms remained stable during different years and seasons. Metabolomic and transcriptomic analyses revealed that fructose and mannose metabolism pathway significantly enriched in both omics datasets. The expression of key enzyme encoding genes from this pathway exhibited various expression patterns. In KF, most genes showed significantly higher expression levels than NF, with synergistic expression predominating among genes. Soluble sugar content was positively correlated with gene expression, while HXK, SDH, and TPI activities were negatively correlated with most genes, and FBP activity was positively correlated with most genes. Genes affect carbon source metabolic flux distribution by promoting sugar synthesis and inhibiting sugar respiration consumption. Exogenous sugar treatment exhibited germplasm-specific and concentration-dependent influence of gene expression, with KF primarily showing negative feedback and NF predominantly activating expression. Fruit flesh thickness was significantly positively correlated with the synergistic high expression of sugar metabolism genes and soluble sugar accumulation. This study provides a theoretical basis for molecular improvement of bitter melon fruit flesh thickness.

Horticulturae doi: 10.3390/horticulturae12050517

Authors: Caroline P. Cardoso Gabriel M. Napoleão Fernanda N. Vargens Larissa S. Rodrigues Priscila Pegorin Luisa S. Gonçalves Lucas Felipe dos Ouros Sarita Leonel Carmen S. F. Boaro

Physalis peruviana L., a South American species, has been increasingly cultivated because of its bioactive compounds and high commercial value. This study evaluated the biochemical responses and fruit quality of physalis plants subjected to different water availability regimes (40%, 70%, and 100% of field capacity), followed by recovery periods. The experiment was conducted at São Paulo State University in a randomized block design with split plots. Plants were exposed to different irrigation regimes and subsequently rewatered over a 120-day period. Leaf and fruit analyses showed that water stress at 40% field capacity significantly increased both enzymatic and non-enzymatic antioxidant levels, thereby mitigating oxidative damage, as indicated by lower lipid peroxidation and reduced reactive oxygen species accumulation. However, this defense response was accompanied by marked reductions in fruit yield, fruit number, fresh mass, and fruit quality. Notably, although rewatering reversed several biochemical stress markers at the leaf level, fruit yield and commercial quality did not recover, suggesting irreversible damage to reproductive development during the stress period. These findings indicate that controlled water deficit may enhance antioxidant accumulation, highlighting the potential of stressed plants for pharmaceutical or nutraceutical applications. However, prolonged water stress, even when followed by a recovery period, impairs commercial fruit production. Therefore, irrigation management should be aligned with the intended production objective.

Horticulturae doi: 10.3390/horticulturae12050516

Authors: Mohammed Mustafa Zita Szalai Márta Ladányi Mónika Máté Gergely Simon Gitta Ficzek György Végvári László Csambalik

The field production of tomato faces challenges regarding abiotic stress factors, which unfavorably impact fruit quality traits. Hedgerows, a form of agroforestry, offer a climate-resilient strategy to buffer temperatures and reduce the impact of direct wind stress on crop production. This study assessed the impact of hedgerow microclimate modulation effects on open-field tomato fruit quality, employing three genotypes (Roma, Ace55, and Szentlőrinckáta). Key quality traits (Total Soluble Solids (TSS), Titratable Acidity (TA), Sugar–Acid Ratio (SAR), Ferric-Reducing Antioxidant Power (FRAP), Total Phenolic Content (TPC), Chroma (C*), and Hue (ho)) were measured over two harvests per season, in two consecutive years (2023–2024). Plots were positioned at five distances (3, 6, 9, 12, and 15 m from the hedge) on both windy and protected sides (W1–W5 and P1–P5, respectively, with 1 showing the closest position). We observed that the microclimate of the protected side was consistently warmer, with an average deviation from the reference temperature of +3.54 °C at mid-distances and +0.38 °C higher overall across both growing seasons. Results show that mid-distance zones (P3–P4, W3–W4) consistently exhibited the highest C* (up to 39.44) at W4 and TSS values at W1 (7.00 °Bx). Protected sides favored higher TA at P3 (0.70%) and Hue (ho) values at P3 with (53.06 ± 0.30) with Ace55 and SAR at P3 (16.35) with Szentlőrinckáta. Windy sides significantly enhanced FRAP and TPC, with the Szentlőrinckáta genotype exhibiting the highest antioxidant capacity at W1 (23.67 mg AAE 100 g−1, FRAP) and TPC (244.17 mg GAE 100 g−1). At W4, Roma showed a 9.4% increase in TPC in the second harvest, while Ace55 showed the highest FRAP values during late-season sampling, highlighting genotype-specific antioxidant resilience under contrasting microclimates. These findings suggest that mid-distance zones and microclimatic variation between windy and protected sides remarkably influence fruit quality traits and antioxidant profiles.

Horticulturae doi: 10.3390/horticulturae12050515

Authors: Zhaoyan Ren Ahua Wang Huihuang Cheng Yawen Liao Ziyue Qin Shengjuan Shi Bingxi Chen Qiyou Shen Hui Yin Fengxian Yao Chen Cheng

Protected cultivation of pepper in southern China’s red soil region often leads to soil degradation and continuous cropping obstacles. To investigate whether biochar can alleviate these problems by regulating the soil microenvironment, pot and incubation experiments were conducted from 2021 to 2023 with biochar application rates of 0~10% (w/w). The results showed that appropriate biochar application significantly improved pepper yield and soil quality. Under the 6% biochar treatment, pepper yield and dry matter accumulation increased by 89.05% and 36.79%, respectively, compared to the control. Soil bacterial and fungal abundances increased by 346.61% and 107.37%, and their OTU numbers rose by 64.13% and 35.15%, respectively. Biochar application also elevated soil pH, organic matter, available potassium, and total nitrogen contents, improved aggregate stability, and enhanced the activities of urease, catalase, sucrase, and acid phosphatase. Furthermore, biochar altered the rhizosphere microbial community structure and increased bacterial diversity. These findings demonstrate that biochar can promote pepper growth by improving soil physicochemical properties, enzyme activities, and microbial community structure, providing a viable strategy for mitigating continuous cropping obstacles in protected cultivation.

Horticulturae doi: 10.3390/horticulturae12050512

Authors: Mengqun Peng Chao Song Fan Li Liang Sun Mei Zhou Chunlian Jin Youguo Wang

ERF/AP2 is a family of transcription factors that plays a broad role in plant growth and development and in responses to various environmental stresses. In our previous studies, we found that the transcription factor LoERF4 indirectly induces the breaking of dormancy in lily bulbs by regulating its downstream gene, LoXTH23. To further investigate the function of LoERF4, we overexpressed it in Arabidopsis thaliana. Paraffin section analysis revealed that root cells in OE-LoERF4 transgenic Arabidopsis thaliana lines exhibited significantly longer average cell lengths compared to the wild type. In the overexpression lines, the expression of multiple modified genes, including AtXTHs and AtEXPAs was significantly upregulated, and these lines exhibited earlier lateral root emergence and a significant increase in primary root length. Under 100 mM sodium chloride treatment, the overexpression lines exhibited significantly higher numbers of lateral roots, true leaves, and primary root length compared with the wild type (WT). In the OE-LoERF4 line, antioxidant enzyme (SOD, POD, CAT) activity was enhanced, oxidative damage was reduced (decreased MDA content), and root survival rate was improved (as reflected by TTC reduction). This confirms that LoERF4 may promote root development in the overexpression line by positively regulating downstream AtXTHs and AtEXPAs, while simultaneously enhancing the salt tolerance of the overexpression line.

Horticulturae doi: 10.3390/horticulturae12050514

Authors: Se Hun Ju Young Je Kim Eun Ji Kim Daegi Kim Youngseok Kwon Jun Gu Lee Jongseok Park Beom Seon Lee Haeyoung Na

Strawberry cultivation generates substantial amounts of agricultural by-products, including spent substrates and plant residues, particularly in hydroponic production systems. However, information on the occurrence and management of these by-products remains limited. This study investigated the generation, disposal practices, and chemical characteristics of by-products from hydroponic strawberry cultivation in two major strawberry-producing regions of Republic of Korea, Nonsan and Jinju. Based on national statistics and field surveys, annual by-product generation was estimated at 605,400 m3 of spent substrates and approximately 25,729 t fresh weight and 6003 t dry weight of plant residues. Disposal practices varied regionally: in Jinju, over 80% of by-products were recycled as compost or feed, whereas in Nonsan, recycling rates were lower and a considerable portion remained untreated or were improperly disposed of. Analyses of 463 pesticides and seven heavy metals (Zn, Cu, Ni, Pb, As, Cd, and Hg) confirmed concentrations below the permissible limits, supporting their chemical suitability for potential recycling use. Inorganic analyses revealed high levels of N, Ca, P, and K, suggesting their potential as alternative nutrient sources and as raw materials for recycled fertilizer or soil amendment. Because strawberry by-products are generated continuously throughout the cultivation cycle, their management requires decentralized and long-term strategies. These results provide the first comprehensive assessment of the generation scale, disposal practices, and chemical characteristics of strawberry by-products in Republic of Korea, suggesting their potential as alternative nutrient resources or raw materials for recycled fertilizer or soil amendment under appropriate pretreatment and management.

Horticulturae doi: 10.3390/horticulturae12050513

Authors: Xiang Li Liqin Liu Xiaowen Hu Shengyou Shi Tianzi Li Jiannan Zhou

The rapid accumulation of genome-scale data has transformed plant biology from descriptive genetics to predictive and increasingly mechanistic genomics. Longan (Dimocarpus longan Lour.) is an economically important subtropical fruit tree in China and Southeast Asia, but compared with model plants and major temperate fruit crops, its genomic resources and functional studies have developed relatively late. Here, we review recent progress in longan genomics with emphasis on three interrelated areas: genome assembly and annotation, transcriptomic resources, and representative gene family studies associated with flowering, somatic embryogenesis, and transporter-mediated stress tolerance. The progression from the first draft genome of ‘Honghezi’ to the chromosome-scale assemblies of ‘Jidanben’ and ‘Shixia’ has substantially improved contiguity and gene annotation, thereby enabling population-genomic analysis, genome-wide gene family identification, and candidate-gene discovery. Available transcriptomic datasets further support studies of reproductive development, stress responses, and embryogenic competence, although cross-study integration remains limited. We also summarize how gene family analyses have advanced the current understanding of floral induction, continuous flowering, somatic embryogenesis, mineral transport, and sugar transport in longan. Importantly, the field is still dominated by cataloguing and expression-based inference, whereas causal validation, pan-genomic analysis, and multi-omics integration remain insufficient. We therefore argue that future progress in longan molecular breeding will depend on integrating high-quality genomic resources with functional validation, standardized comparative annotation, and improved transformation or regeneration systems.

Horticulturae doi: 10.3390/horticulturae12050511

Authors: Marco Castellacci Andrea Cavallini Margarita López-Corrales Ghada Baraket Arzu Ayar María Guadalupe Domínguez Songul Comlekcioglu Antonio Jesús Galán Ana María Fernández-León Manuel J. Serradilla Fateh Aljane Sahar Haffar Amel Salhi Hannachi Aymen Aounallah Ayzin Kuden José Inaki Hormaza Tommaso Giordani

The fig tree (Ficus carica L.) is one of the oldest cultivated fruit trees in the Mediterranean region and represents an important genetic resource for both traditional and emerging production systems. Despite its agronomic and economic relevance, modern fig breeding remains limited, and large-scale phenotypic evaluations across Mediterranean germplasms are still scarce. The objective of this study was to assess phenotypic diversity and identify key agronomic traits relevant for fig breeding. A total of 257 female fig genotypes conserved in germplasm banks located in Spain, Turkey, and Tunisia were used. Over two consecutive seasons (2021 and 2022), a total of 27 morphological, phenological, and pomological traits were assessed according to the International Union for the Protection of New Varieties of Plants (UPOV) descriptors for fig (TG265/1), with 23 phenotypic traits retained for statistical analyses. Linear mixed models were used to estimate marginal means and to partition genetic and environmental variance, while multivariate analyses and trait correlations were employed to explore the structure of phenotypic diversity. The germplasm exhibits remarkable variation in productive type, reproductive behaviour, harvesting date, and fruit quality traits. Harvesting date spans nearly three months. Fruit weight ranges from 11.7 to 134.5 g, total soluble solids from 9 to 39 °Brix, and maturation index values reached high levels, indicating pronounced sweetness during fruit ripening. Most genotypes showed high skin scratch resistance, absence of cracking at maturity, and medium or small ostiole size, highlighting the presence of ideotypes specifically suited for fresh market production. Heritability estimates indicate strong genetic control of key traits, such as fruit weight, fruit size, and total soluble solids, highlighting their suitability for selection in breeding programs. Stakeholder prioritisation further confirmed the relevance of fruit size, sweetness, firmness, and ostiole characteristics, helping to identify best genotypes for breeding and agronomic purposes. Overall, this study demonstrates the value of Mediterranean fig germplasm as a reservoir of valuable agronomic and commercial traits and provides a robust phenotypic framework to support future breeding, conservation, and cultivar selection strategies.

Horticulturae doi: 10.3390/horticulturae12050510

Authors: Junru Chen Manyao Guo Susu Tie Xiaobei Wang Haipeng Zhang Xiaodong Lian Nan Hou Jiancan Feng Lei Wang Bin Tan

Walnut is an important nut with a rich nutritional profile and associated health benefits for the human body. B-box (BBX) proteins containing one or two BBX motifs play pivotal roles in plant growth and developmental processes; nevertheless, the functions of JrBBXs in walnut anthocyanin biosynthesis remain inadequately understood. In this study, 39 JrBBXs in red walnut ‘RW-1’ were identified, with phylogenetic analysis suggesting that they were divided into six classes based on the distribution of conserved domains and unevenly distributed on 14 chromosomes. Promoter analysis demonstrated that JrBBX promoters possessed an abundance of light responsiveness elements, ABA responsiveness elements, MYB binding sites and MYC binding sites. The transcriptome analysis results demonstrated that eight JrBBXs were differently expressed in normal green walnut ‘Zhonglin 1’ and red walnut ‘RW-1’ seed coats. Furthermore, qRT-PCR (quantitative real-time polymerase chain reaction) analysis showed that JrBBX3 exhibited lower expression during seed coat development in ‘RW-1’. Y1H (Yeast One-Hybrid) and LUC (dual-luciferase reporter) assays revealed that JrBBX3 directly inhibited the expression of JrUFGT5, considered a key anthocyanin biosynthesis structural gene in research. Subcellular localization analysis indicated both cytoplasmic and nuclear localization of JrBBX3. Transient overexpression of JrBBX3 in walnut leaves resulted in reduced JrUFGT5 expression and anthocyanin accumulation. Collectively, these findings revealed the negative regulation of JrBBX3 in red walnut anthocyanin biosynthesis, and provided a basis to further study the anthocyanin biosynthesis mechanism of red walnut.

Horticulturae doi: 10.3390/horticulturae12050509

Authors: Gabriel Silva Aparecido Valdomiro Junior Neres Santos Felipe Rezende de Moura Ribeiro Renata dos Santos Torelli Bruno Henrique Leite Gonçalvez Aloísio Costa Sampaio Magali Leonel Marco Antonio Tecchio Sarita Leonel Marcelo de Souza Silva

Brazil, as one of the world’s leading fruit producers, faces increasing challenges arising from climate change, particularly in avocado cultivation, where excessive solar radiation and high temperatures impair plant metabolism, yield, and fruit quality. This study evaluated the use of a calcium and magnesium hydroxide-based sunscreen in mitigating heat stress in eight-year-old ‘Hass’ avocado trees. The experimental design was a randomized complete block design in a 4 × 8 factorial arrangement, with five replicates. Sunscreen applications were performed at full bloom and at the initial fruit development stage (18 mm). Leaf temperature, fruit drop rate, yield-related traits, fruit classification, and the percentage of fruit lesions were evaluated. Applications of the calcium and magnesium hydroxide-based sunscreen at concentrations of 3.0% and 4.5% (w/v) reduced leaf temperature and improved fruit biometric attributes compared to the control, although the maximum fruit diameter was achieved at the 2.6% concentration. The 4.5% sunscreen concentration reduced leaf temperature and fruit drop in ‘Hass’ avocado trees by 1.5 °C and 24.5%, respectively, compared with the control and decreased the percentage of small and damaged fruits. The application of sunscreen improved fruit weight and the percentage of fruits with higher market value, while the fruit diameter presented higher values at intermediate concentrations.

Horticulturae doi: 10.3390/horticulturae12050508

Authors: Nkosikhona Goodman Magwaza Sandiswa Figlan Rebogile Ramaesele Mphahlele Mdungazi Knox Maluleke

Background: Indigenous African fruits, like the African horned cucumber (Cucumis metuliferus), are abundant in nutrients and serve as a source of food and raw materials for manufacturing value-added products in both rural and urban areas. This review presents a comparative analysis of selected fruits in the Cucurbitaceae family, specifically in terms of the phytochemical, biochemical and mineral constituents, as well as nutritional contribution, and aims to explore how the African horned cucumber measures up to its counterparts by comparing their nutritional content against the recommended daily intake (RDI). Material and Methods: A literature search—using the keywords ‘African horned cucumber’, ‘Cucurbitaceae fruits’, ‘biochemical constituents’, ‘indigenous fruits’ and ‘recommended daily intake’—was used to gather credible data suitable for this review paper. Findings and Conclusions: The published peer-reviewed literature reveals that the African horned cucumber—with its nutrient-rich profile boasting high levels of calcium (19%), potassium (28%), magnesium (78.1%), sodium (10.7%), zinc (12.7%), beta carotene (15.5%), vitamin C (4.1%), vitamin E (15.2%), total flavonoids (0.28%), and total phenols (0.7%)—holds the promise of contributing significantly to the human diet while aligning with the RDI and dietary guidelines, as documented in studies, further underscoring its potential to meet nutritional needs and enhance health, thus supporting its consideration for commercialisation.

Horticulturae doi: 10.3390/horticulturae12040506

Authors: Yonghui Zhao Ruonan Li Zixian Song Ruitong Zhang Yuxuan Bai Wei Fu Hui Feng

Chinese cabbage is one of the major vegetable crops in northern Asia. Its leaves are the major organ for photosynthesis and production, and leaf color directly influences its yield and quality. Here, we obtained a pale green mutant pgm3. This mutant line was derived from EMS mutagenesis of Chinese cabbage DH line FT. pgm3 exhibited chlorosis and etiolation, delayed growth, reduced photosynthetic pigment content and net photosynthetic rates, and impaired development of the chloroplast inner membrane system. Genetic analysis revealed that the pale green phenotype was controlled by a single recessive nuclear gene, Brpgm3. Mutmap analysis indicated that Brpgm3 is located on a 13.9 Mb region in A03. Within this region, a single SNP (A03: 7194530) with an SNP-index of 1, located in BraA03g015750.3C (BrClpC1), was identified from 40 differential SNPs. KASP genotyping demonstrated that the SNP co-segregated with the pale green phenotype in the F2 population. Sanger sequencing confirmed a G-to-A SNP in exon 4 of BrClpC1, which resulted in an amino acid substitution from S to G. Furthermore, multiple sequence alignment of homologs from 28 species demonstrated that this mutated residue is highly conserved. BrClpC1 was predominantly expressed in leaves and exhibited the highest transcript abundance among the nine members of the Class I Clp gene family in Brassica rapa. This is the first report identifying ClpC1 in Brassica crops. Our results not only confirmed BrClpC1 as a strong candidate gene for the pale green mutant of Chinese cabbage, but also highlighted BrClpC1 as a target for chloroplast biology research in Brassica crops.

Horticulturae doi: 10.3390/horticulturae12040507

Authors: Fengfeng Du Jixiang Liu Xuhui Kan Xixi Li Dongrui Yao Xiaojing Liu

Salt stress poses a major environmental challenge that leads to ecological imbalance and reduced agricultural productivity globally. Sapium sebiferum, a highly valued ornamental and perennial woody oil species, shows promise for saline land utilization due to its natural salt stress adaptability. However, the underlying mechanisms remain largely unexplored. This study investigated the responses of S. sebiferum to salt stress by integrating RNA sequencing and Non-invasive Micro-test Technology (NMT). Comparative transcriptome analysis identified 693, 1061, and 1851 differentially expressed genes at 1 h, 3 h and 6 h after salt treatment, respectively. Functional analysis of DEGs revealed that genes related to ion binding, transmembrane transport, and signal transduction were significantly enriched. Notably, genes involved in calcium (Ca2+) and phytohormone signaling were altered, activating stress-response pathways. Furthermore, the dynamic effects of salt stress on nitrate (NO3−) and ammonium (NH4+) uptake were assessed. After salinity stress (150 mM NaCl), an increase in the net influx of NO3− was observed under the conditions of the assay, while the net flux of NH4+ did not show a significant change. The differential expression of NRT genes suggests that NO3− may play a multifaceted role in salinity tolerance, potentially contributing to nutrition, ion homeostasis, and signaling pathways. The coordinated signaling network likely allows S. sebiferum to effectively cope with salinity stress and sustain physiological functions under challenging conditions. These findings provide valuable insights into the molecular basis of salt tolerance in S. sebiferum, thereby supporting sustainable practices in saline environments.

Horticulturae doi: 10.3390/horticulturae12040505

Authors: Xing Yang Liping Bai Tai Zhang Rongzhen Wu

Automated fruit harvesting is crucial for alleviating labor shortages and enhancing agricultural productivity. In this context, it is crucial to obtain information on fruit poses before picking in order to avoid damaging the fruit and/or the plant. However, the complex and unstructured orchard environment poses significant challenges regarding the pose estimation task. In this study, a dragon fruit pose estimation (DFPE) framework using a single RGB image is proposed for dragon fruit automated harvesting, which includes three key components: dataset annotation processing, keypoint detection, and geometric pose estimation. First, a multi-source dataset consisting of 8467 images is constructed to enhance the estimation model’s generalizability. A pseudo four-keypoint annotation strategy is designed to fit the annotation rules of mainstream single-class keypoint detection models and mitigate the inherent limitations of multi-target keypoint detection in agricultural scenarios. This strategy implicitly encodes the fruit’s orientation using bounding box group IDs, while preserving geometric information for pose inference. Then, the fruit body and its two core keypoints (navel and stem) are detected via a real-time keypoint detection model. Notably, the proposed DFPE framework is detector-agnostic: other mainstream keypoint detection models can also be plugged into the subsequent geometric pose inference stage, which guarantees the generality and scalability of the framework. Finally, a dragon fruit pose estimation algorithm based on customized geometric constraints is designed, which takes the detected pose information as the input and outputs the posture of dragon fruit. The results of experiments conducted in natural orchard and laboratory environments demonstrate that the ellipses fitted using the proposed DFPE framework closely aligned with fruit contours, even under foliage occlusion conditions. In the laboratory environment, roll errors reached a maximum of 14.8°, whereas yaw errors peaked at 13.4°. Crucially, all roll and yaw errors remained consistently below 15°, which is well within the tolerance threshold required for non-destructive picking operations using a harvesting robot. In summary, this work presents a low-cost solution for dragon fruit pose estimation from a single RGB image, which can potentially be extended to other ellipsoid crops and is suitable for implementation in harvesting robots operating in orchards.

Horticulturae doi: 10.3390/horticulturae12040504

Authors: Minghua Lou Yang Chen Dengfeng Shen Bin Wei Jianhong Zhang

Camellia japonica is a widely cultivated woody ornamental plant. However, current studies mostly focus on the onset of flowering, neglecting the overall flowering time distribution patterns of the blooming process. In this study, we used uniform 5-year-old potted cuttings of C. japonica ‘Jinjiang Mudan’ to evaluate six candidate distribution models, including normal, log-normal, skew-normal, gamma, Weibull, and exponential, to model flowering time distribution. These candidates were compared to obtain an optimal distribution model using three-fold cross-validation, six evaluation indicators, and three goodness-of-fit tests in the control. The optimal distribution model was used to compare and analyze the different effects of the control, shading, and exogenous hormone treatments. The results showed that the skew-normal distribution model emerged as the most suitable distribution model among the six candidates and captured the flowering time distribution characteristics effectively in all treatments. Shading treatments were found to delay and extend the flowering period, with moderate treatments (50% and 70% shading) demonstrating better performance, extending the flowering period by approximately 40%. In terms of exogenous hormone treatments, BG (a mixture of the 6-BA and GA3) concentrations could prolong and delay the flowering period. Lower concentrations (100 and 250 mg L−1) of 6-BA and GA3 were effective in extending the flowering period, with BA250 exhibiting the most pronounced effect, delaying flowering onset by approximately 12% and extending the flowering period by approximately 17%. Considering that this study is based on single-location and single-season trials, these findings provide a valuable methodological resource for quantifying and predicting flowering time distribution in C. japonica, other ornamentals, and crops.

Horticulturae doi: 10.3390/horticulturae12040502

Authors: Feilong Hu Zhe Zhang Shunjiao Lu Zhiheng Chen Haotian Zhong Liang Xi Guangsui Yang

Cymbidium eburneum Lindl. is a valuable ornamental orchid and breeding parent, but its genetic background remains unclear due to habitat destruction and germplasm mixing. This study developed specific SSR markers to evaluate the genetic diversity and structure of 96 C. eburneum Lindl. accessions from China and Vietnam. Transcriptome analysis identified 47,248 SSR loci. Sixteen polymorphic core primer pairs detected 150 alleles (mean Na = 9.375) with an average Polymorphism Information Content (PIC) of 0.444. Observed heterozygosity (Ho = 0.290) was noticeably lower than expected (He = 0.478), indicating heterozygote deficiency. UPGMA clustering identified eight groups strongly correlated with geography. Principal Coordinate Analysis (PCoA) revealed a clear geographical differentiation pattern, featuring the most genetically cohesive group from Guangxi and more differentiated geographically marginal populations from Hainan and Vietnam. STRUCTURE analysis (K = 2) indicated two main gene pools with signals of genetic admixture. Geographical isolation was suggested as a potential driver of genetic differentiation. The Guangxi population represents a genetically consistent major reservoir, while marginal populations harbor unique variations. These findings provide a scientific basis for germplasm identification, conservation, and parental selection in C. eburneum Lindl. breeding.

Horticulturae doi: 10.3390/horticulturae12040503

Authors: Xiaoxiao Li Xin Zhao Xianqing Zheng Xiaoshuang Han Fanlei Meng Weiguang Lv Yue Zhang Ke Song

Continuous greenhouse watermelon cultivation is widely constrained by declining soil function, impaired nutrient cycling, and increasing soil-borne disease pressure. Developing biologically driven strategies to restore soil–crop coupling is therefore critical for sustainable protected horticulture. Here, we conducted a two-year field experiment (2024–2025) using a randomized block design with three treatments (CK, ST, and STE), three replicates per treatment, and a plot area of 22.5 m2 to evaluate how straw application alone and in combination with earthworms regulate soil processes and crop performance in a continuous greenhouse watermelon system. Compared with CK and ST, earthworm–straw co-application (STE) exerted stronger effects, particularly during the mid-to-late growth stages. In 2024, STE increased soil organic matter by 25.34% and 30.28% relative to CK at the fruiting and harvest stages, respectively; in 2025, the corresponding increases were 25.22% and 27.62%. STE also significantly increased total nitrogen at nearly all growth stages, with the maximum increase reaching 67.23% relative to CK at harvest. In 2025, total phosphorus under STE was significantly higher than under CK and ST across all growth stages, with increases of 75.82% and 79.63%, respectively, at the fruiting stage. Neutral phosphatase activity was markedly enhanced, increasing by 292.24% at the fruiting stage in 2025. These improvements were accompanied by higher plot yield and lower wilt disease incidence, with yield increasing by 34.00% in 2024 and 21.29% in 2025 relative to CK, while disease incidence decreased by 41.46% and 56.06%, respectively. Integrative Mantel tests showed that total nitrogen was the factor most strongly associated with watermelon yield, with the correlation coefficient increasing from r = 0.490 (p = 0.001) in 2024 to r = 0.662 (p = 0.001) in 2025. Co-occurrence network analysis further revealed a strong positive correlation between yield and total nitrogen (r = 0.848 in 2024; r = 0.673 in 2025) and a negative correlation between disease incidence and total nitrogen (r = −0.661 in 2024; r = −0.822 in 2025), indicating progressively strengthened soil–plant functional coupling over time. Our findings demonstrate that earthworm–straw co-application strengthened soil nutrient transformation capacity and enhanced soil suppressiveness against wilt disease, thereby providing an effective ecology-based strategy for alleviating continuous-cropping constraints in greenhouse watermelon systems.

Horticulturae doi: 10.3390/horticulturae12040501

Authors: Jolan Schabauer Erich Streit Azra Korjenic Jitka Peterková Jiří Zach Abdulah Sulejmanovski

Mineral substrates for indoor horticulture systems critically determine plant water availability and irrigation demand. However, integrative assessments linking pore structure, water retention, and evaporation dynamics of commonly used mineral growing media remain scarce. A total of nine distinct mineral substrates were investigated: expanded clay, expanded slate, pumice, perlite, zeolite, vermiculite, lava granules, brick chips, and clay granules. To assess the impact of granulometry, pumice was tested in three different grain sizes (1–3 mm, 4–7 mm, 7–14 mm), resulting in a total of 11 experimental samples. Samples were characterized using scanning electron microscopy (SEM), suction experiments, and evaporation tests at 30%, 50%, and 70% relative humidity (RH) at 23 °C. Bulk density ranged from <0.12 g·cm−3 (perlite, vermiculite) to >0.99 g·cm−3 (zeolite, brick chips), while volumetric water content varied from 11.0 vol.% (expanded clay) to 46.6 vol.% (vermiculite). Plant-available water content (AWC) ranged from 2.7 vol.% (expanded clay) to 30.9 vol.% (clay granules). These results demonstrate that pore interconnectivity, rather than total porosity, is the decisive driver of hydraulic performance. Finer pumice fractions increased water retention by ~16% compared to coarser fractions. All substrates exhibited a two-phase evaporation profile, with initial rates ranging from 1.9 to 5.6 g·h−1 at 30% RH. Clay granules showed the most temporally stable evaporation, with only a 37% rate reduction over 48 h, compared to 66% for perlite. While conducted under controlled laboratory conditions, these findings provide a quantitative basis for targeted substrate selection and blending to optimize root-zone hydration, irrigation efficiency, and hygrothermal performance in permanent indoor horticulture systems.

Horticulturae doi: 10.3390/horticulturae12040500

Authors: Yu Huang Chunyan Ma Meng Zou Jinglin Shen Feifei Yang Yuping Zhao Lili Hao Qianqian Sheng Zunling Zhu

Efficient cultivation is essential for the rose industry. Both substrate formulation and plant growth-promoting rhizobacteria (PGPR) application both critical, yet their synergistic effects remain limited. This study investigated the synergistic effects of Bacillus subtilis (Bs) and Priestia megaterium (Pm) combined with five substrate formulations on the growth physiology, photosynthetic characteristics, and soil properties of Rosa × hybrida ‘Ruby’. Two-way ANOVA revealed significant interactions between substrate and PGPR treatments for most growth and physiological indicators. Orthogonal experiments demonstrated that specific PGPR–substrate combinations significantly enhanced plant growth and photosynthetic performance of the studied cultivar, as well as soil quality. Principal component analysis and membership function analysis identified four substrate–PGPR combinations as optimal, with the T4 substrate (humus/perlite/vermiculite/coconut coir/peat/biochar = 5:1.5:1:1:1:0.5) showing the most pronounced effects. In this T4 substrate, PGPR inoculation significantly altered the rhizobacterial community structure. LEfSe analysis revealed 67 enriched microbial biomarkers—substantially more than single-strain treatments. The relative abundance of beneficial genera such as Acidibacter and Chryseotalea increased, and the combined bacterial treatment enhanced functional pathways associated with signal transduction, cell motility, and RNA processing. Compared to single-strain treatments, the combined bacterial application demonstrated superior regulatory effects on plant growth. The optimal combined treatments increased plant height by up to 42.7%, root activity by 103.0%, soluble protein content by 302.8%, and soil ammonium nitrogen by 168.8%. These findings demonstrated that tailored combinations of PGPR and cultivation substrates highlight the potential for optimizing rose cultivation and improving the rhizosphere microecological environment.

Horticulturae doi: 10.3390/horticulturae12040499

Authors: Nikolaos Polyzos Antonios Chrysargyris Maria del Mar Alguacil Nikolaos Tzortzakis Spyridon A. Petropoulos

The application of biostimulants is a promising tool for enhancing plant growth and crop quality in the context of sustainable and resilient agricultural production. This study evaluated four microbial biostimulants (IMB1–4) on Sonchus oleraceus L. under field and pot cultivation. Our results indicate that the growing system was a more dominant factor than biostimulants in influencing plant performance. For morphological and growth traits, biostimulants generally had a neutral or negative impact compared with untreated plants, with IMB3 consistently showing the lowest performance. Field-grown plants, especially the untreated ones, excelled in plant weight and leaf count, while pot-grown plants treated with IMB2 and IMB4 achieved higher leaf weight per plant, leaf area, and chlorophyll index (SPAD). Specifically, untreated field plants recorded the highest biomass, whereas IMB2 and IMB4 optimized leaf traits in pots. Biostimulant applications enhanced fat content and energetic value, with IMB1 and IMB2 yielding the highest protein levels. Pot cultivation favored the accumulation of nitrogen, phosphorus, and sodium, while IMB2-treated pot plants proved most effective for maximizing overall nutrient content. The phytochemical profile also varied by system: pot-grown plants yielded higher total phenols, particularly with IMB3, while field-grown plants recorded higher flavonoids, especially with IMB4. Furthermore, untreated or IMB3-treated pot plants exhibited the highest antioxidant activity, significantly outperforming field-grown counterparts. In conclusion, while biostimulants did not improve morphological and growth traits, they significantly enhanced the nutritional and phytochemical quality of S. oleraceus L., particularly in the pot cultivation system, where specific biostimulants (IMB2 and IMB3) resulted in nutrient-dense crops with high antioxidant value.

Horticulturae doi: 10.3390/horticulturae12040498

Authors: Jae Hwan Lee Yeong Sunwoo Eun Ji Shin Sang Yong Nam

This study evaluated the effects of different light-emitting diode (LED) spectral qualities on the early growth of kale at the baby-leaf harvest stage in a plant factory with artificial lighting (PFAL) by integrating morphological traits, biomass accumulation, plant quality indices, vegetation indices, and chlorophyll a fluorescence. Two kale (Brassica oleracea L.) cultivars, ‘Jellujon’ and ‘Manchoo Collard’, were grown for four weeks under monochromatic red, green, and blue LEDs, a purple composite LED with far-red wavelengths, and three white LEDs with different correlated color temperatures (3000, 4100, and 6500 K). Blue LED increased shoot height by approximately 14–28%, depending on cultivar and comparison among the white LED treatments, but this elongation did not translate into superior biomass production. In contrast, white LEDs, particularly at 3000–4100 K, increased leaf area to 24.2–24.9 cm2 and SPAD units to 47.3–50.2, whereas blue or green LEDs generally resulted in smaller leaves and lower SPAD units. Shoot dry weight under 3000–4100 K white LEDs reached 0.25–0.26 g in ‘Jellujon’ and 0.26–0.29 g in ‘Manchoo Collard’, approximately twofold higher than under blue or green LEDs. Compactness, Dickson quality index, root investment ratio, and leaf efficiency index were also more favorable under white LEDs, indicating improved plant sturdiness and structural stability. Green LED light was associated with lower maximum photochemical efficiency (ΦPo) and greater energy dissipation (ΦDo and DIo/RC), whereas photochemical reflectance index and PIABS tended to be more favorable under selected white LED treatments, although these responses were partly cultivar- and treatment-dependent. Taken together, among the LED spectral quality treatments tested, 3000–4100 K white LEDs provided the most consistently favorable conditions for producing structurally robust, high-quality kale at the early growth stage in PFAL systems. The purple LED showed partial advantages in leaf development and selected physiological responses, but these effects were less consistent across cultivars and indices.

Horticulturae doi: 10.3390/horticulturae12040497

Authors: Mohammad Gul Arabzai Ting Wu Nazir Khan Mohammadi Niaz Mohammad Inqilabi Omotola Adebayo Olunuga Yuan Qin Lulu Wang

The genus Passiflora includes species important for fruit production, ornamental value, and breeding programs. Conventional methods, such as seed propagation and vegetative cuttings, face challenges like genetic heterogeneity, pathogen transmission, and long juvenile phases, limiting large-scale cultivation and breeding efficiency. In vitro culture technologies are essential for clonal propagation, germplasm conservation, and improving Passiflora species using biotechnology. This review critically evaluates current progress in micropropagation and regeneration systems in Passiflora spp. and examines the prospects of haploid and doubled haploid technologies as future breeding tools. Unlike previous reviews, which primarily focus on summarizing tissue culture protocols, this study integrates regeneration biology, developmental constraints, and emerging biotechnological approaches to provide a broader framework for research. Additionally, this review offers a comparative analysis of various regeneration systems across Passiflora species and highlights the challenges of genotype-dependent methods. By synthesizing recent advancements in haploid technology, it provides new insights into the potential for accelerating breeding programs in Passiflora, a field where robust protocols are still lacking.

Horticulturae doi: 10.3390/horticulturae12040496

Authors: Shiyu Dai Yanling Peng Hede Gong

Frequent co-occurrences of high temperature and drought in tropical regions make heat and drought tolerance of landscape plants core physiological traits that determine their landscape adaptability and community stability. However, systematic elucidation of the differentiation patterns of stress resistance between specialist and generalist tropical landscape plant species, the intrinsic correlations between heat and drought tolerance traits, and the regulatory mechanisms of leaf functional traits remains lacking. In this study, eight typical tropical landscape plant species in Xishuangbanna Tropical Botanical Garden were selected as research objects. By determining leaf chlorophyll fluorescence parameters, water relation parameters and leaf functional traits, we systematically analyzed the differences in heat and drought tolerance and interspecific differentiation characteristics between specialist and generalist species, and simultaneously elucidated the correlation patterns of drought-heat tolerance traits as well as the regulatory effects of leaf functional traits on these traits. The results showed that the turgor loss point water potential (ΨTLP) of generalist tropical landscape plant species was significantly higher than that of specialist species, with superior drought tolerance; in contrast, the half-lethal temperature of photosystem II (T50) of specialist species was significantly higher than that of generalist species, with stronger heat tolerance. Among the eight tested species, Bombax ceiba exhibited the strongest drought tolerance, while Baccaurea ramiflora had the optimal heat tolerance. The study also found that the drought and heat tolerance traits of tropical landscape plants exhibited stress-specific trade-offs; leaf functional traits had limited overall explanatory power for the stress resistance of tropical landscape plants and only exerted a certain regulatory effect on drought tolerance. This study clearly reveals the differences in heat and drought tolerance between specialist and generalist species. This finding not only enhances our mechanistic understanding of stress resistance in tropical plants but also provides data support for ecological restoration and conservation practices in tropical gardens.

Horticulturae doi: 10.3390/horticulturae12040495

Authors: Xianfang Zou Tianxing Yuan Yuxin Zhang Xiaohan Zhang Guoqing Niu Yulong Guo

Datura species are valued ornamentals but contain toxic tropane alkaloids (TAs) like hyoscyamine and scopolamine, which restrict their safe horticultural use. To address this, we developed a genome editing platform in Datura inoxia for creating non-toxic varieties. We first established an efficient, auxin-independent shoot regeneration system using a novel cytokinin combination (thidiazuron and 6-benzylaminopurine) achieving over 7 shoots per explant. This system facilitated an Agrobacterium tumefaciens-mediated transformation protocol with a stable efficiency exceeding 50% (49 independent lines from 100 explants for LS; 36 lines from 70 explants for CYP80F1). Using this platform, we performed CRISPR/Cas9-mediated knockout of two key TA biosynthetic genes, LS (littorine synthase) and CYP80F1 (littorine mutase). Among the transgenic lines analyzed, 8 out of 15 (53%) carried mutations in LS, while all 12 (100%) lines carried mutations in CYP80F1. HPLC and high-resolution mass spectrometry confirmed the complete absence of hyoscyamine and scopolamine in the mutant leaves, with no detectable peaks at the corresponding retention times. Crucially, the edited plants grew normally and were morphologically indistinguishable from the wild type. This work establishes the first CRISPR/Cas9 platform for Datura and generates the first non-toxic germplasm, providing both a functional genomics tool and a foundation for breeding safe ornamental cultivars.

Horticulturae doi: 10.3390/horticulturae12040494

Authors: Bin Yan Qianru Wu

Achieving precise fruit localization and fine branch segmentation simultaneously in unstructured orchard environments remains challenging due to variable lighting, occlusion, and complex backgrounds. This study proposed a joint detection–segmentation architecture based on an improved YOLOv11 network for collaborative perception of apples and tree branches. First, a dual-task dataset of spindle-type apple orchards was constructed with bounding-box annotations for fruits and pixel-level polygon masks for branches, encompassing diverse illumination and occlusion conditions. Second, Convolutional Block Attention Modules (CBAMs) are strategically embedded into the YOLOv11 backbone to enhance feature discrimination for slender branch structures while preserving high fruit detection accuracy. The enhanced model achieves precision of 0.981, recall of 0.986, and F1-score of 0.983 for apple detection, and precision of 0.803, recall of 0.715, mAP of 0.698, and IoU of 0.6066 for branch segmentation on the validation set. Comparative experiments against YOLOv8 and baseline YOLOv11 confirm improved segmentation continuity and finer branch delineation. The proposed integrated perception framework provides reliable visual guidance for collision-avoidance robotic harvesting and offers a practical reference for multi-task agricultural vision systems.

Horticulturae doi: 10.3390/horticulturae12040493

Authors: Gaetano Distefano Ossama Kodad Ilaria Inzirillo Khaoula Allach Chiara Catalano Leonardo Paul Luca Virginia Ruiz Artiga María Teresa Espiau Ramírez Jerome Grimplet Beatriz Bielsa Meryem Erami Aydin Uzun Adnane El Yaacoubi Maria J. Rubio-Cabetas

Almond (Prunus dulcis (Mill.) D.A. Webb) is one of the most economically important nut crops worldwide, valued for its nutritional properties and adaptability to diverse agroecological environments. This review summarizes current knowledge on almond domestication, genetic diversity, production trends, and improvement strategies, with a focus on drought tolerance under climate change. Archaeobotanical and molecular evidence indicate central Asia and the eastern Mediterranean as key centers of origin, where recurrent introgression from wild Prunus species contributed to the high genetic variability of cultivated almond. Global production trends reveal increasing challenges due to prolonged drought, climate variability, and rising water and energy costs, particularly affecting major producers such as the United States. Mediterranean regions are transitioning from traditional low-density orchards to intensive systems, where cultivar and rootstock choice are crucial for sustainability. Self-fertile and late-blooming cultivars improve yield stability, while interspecific hybrid rootstocks enhance water use efficiency and tolerance to drought and poor soils. Drought stress impacts almond physiology and yield, although moderate deficit irrigation can maintain productivity and improve kernel quality. Future improvement relies on germplasm conservation, marker-assisted selection, and genomic tools to develop climate-resilient cultivars integrated with sustainable water management strategies.

Horticulturae doi: 10.3390/horticulturae12040492

Authors: Prasanth Tej Kumar Jagannadham Anbazhagan Thirugnanavel Tejaswini S. Parteki Dedoas T. Meshram Anoop Kumar Srivastava Vasileios Ziogas

Citrus genomes as storehouses of genetic information of immense commercial utility remain untapped for the improvement of fruit quality traits and other production-related stresses. With the rapid expansion of transcriptomic datasets, integrative meta-analysis has further aided in uncovering interspecies molecular mechanisms associated with fruit quality development. In this study, we performed a cross-project RNA-Seq meta-analysis, integrating multiple publicly available BioProjects encompassing diverse citrus species, viz., Citrus sinensis, C. reticulata, C. maxima, C. clementina, C. japonica, and C. papeda, known to dominate the morphogenetic evolution of the citrus industry. High-throughput RNA-Seq data were processed using various bioinformatics tools. A total of 15 interspecies comparisons identified 676 unique DEGs, enriched in pathways related to secondary juice yield and processing quality traits. We also established that domestication aided in metabolism, oxidative stress responses, phenylpropanoid and flavonoid biosynthesis, and hormone-mediated signaling. Multivariate analyses (PCA and heatmap visualization) highlighted distinct yet overlapping expression patterns across these citrus species. By combining differential expression, co-expression network analysis and QTL-GWAS integration, we identified 19 high-confidence candidate genes responsible for transcriptomic variation associated with measurable fruit quality traits. Genes such as LOC102612823 and LOC102607495, which co-localized with seed number QTLs on chromosome 1, represented strong candidates regulating reproductive development and seed formation, the traits that directly influence fruit texture and market acceptability. Genes linked to juice content QTLs, including LOC102611137 and LOC102612553 on chromosome 5, suggested their roles in metabolic regulations behind juice accumulation. These loci provided definitive breeding clues for enhancing the reshaping of citrus fruit transcriptomes while retaining key ancestral regulatory components.

Horticulturae doi: 10.3390/horticulturae12040491

Authors: Mahdi Faraji Saham Mirzaei Rasoul Rahnemaie Shahriar Mahdavi Alessandro Pistillo Giuseppina Pennisi Afsaneh Nematpour Andrea Strano Michele Consolini Francesco Spinelli Francesco Orsini

The starch and moisture content of saffron corms are critical indicators of their flowering potential and yield. This study investigated the use of rapid, minimally invasive VNIR reflectance spectroscopy measurement to assess these parameters. The measurements were used to develop predictive models through four machine learning algorithms (PLSR, RF, SVR, and GPR). Spectral data were obtained from 130 fresh corm samples. Wavelength analysis identified key starch-sensitive intervals (~930–1000 nm and ~1150–1220 nm) and a broad moisture-sensitive region (~900–1350 nm). Among the evaluated models, the combination of the multiplicative scatter correction pre-processing method and Gaussian process regression (MSC-GPR) demonstrated the optimal predictive performance for water content (R2 = 0.92, RMSE = 0.71%, RPD = 4.56, RPIQ = 5.37), and the combination of the MSC method and partial least squares regression (PLSR-MSC) demonstrated moderate performance for starch content (R2 = 0.73, RMSE = 28.7 mg g−1, RPD = 2.14, RPIQ = 2.81, dry weight). These results demonstrate the viability of VNIR spectroscopy as a minimally invasive tool for the pre-planting assessment of saffron corm quality under laboratory conditions. The method provides a laboratory-based framework for corm screening and selection, with potential for future adaptation to field settings using portable spectrometers following expanded calibrations and advanced modeling techniques.

Horticulturae doi: 10.3390/horticulturae12040490

Authors: Loretta Bacchetta Sergio Musmeci Oliviero Maccioni Maurizio Mulas

Opuntia ficus-indica (L.) Mill., also named Cactus pear, is a crop widespread in many countries with Mediterranean and subtropical climates, where it represents a valuable source of food. However, in southern Europe, this fruit market is limited to a few months, from summer to autumn. The possibility to extend the ripening period of fruit is represented by the special pruning of the first bloom flush and consequent new development of late flowers and fruits. Extending the cultivation period would allow farmers to maximize the crop’s potential, thereby extending the Cactus pear market season throughout much of the year. In this study, conducted in southern Sardinia (Italy), progressive pruning was applied with the aim of evaluating the fruit characteristics in relation to this type of cultivation, also considering the weather conditions during the experimental period. Morphological traits and physicochemical compositions of fruit picked in four harvests during two sampling seasons from August 2022 to March 2023, and from August 2023 to March 2024 were compared. According to principal component analysis (PCA), most of the observed characters showed significant differences among harvest periods but also between the two seasons of cultivation (year of cultivation: r = 0.722 on PC1), suggesting that the meteorological trend strongly modulated fruit traits. Some fruit qualities were partially lost during the winter months, such as juice acidity and total soluble solids (TSS). October was the month with the highest TSS levels (13.5 ± 0.25), followed by August, January and March. On the other hand, juiciness and fresh weight remained unchanged or even improved in fruit harvested out-of-season. As observed in the redundancy analysis (RDA) a contribution of 54% due to weather variability emerged. In Particular, TSS levels, pH and juice dry matter were associated with high temperatures, solar radiation, and wind intensity. Wind speed was also moderately linked with betalain content. Moreover, high relative humidity was associated with lower pH values, higher water content, and higher fruit fresh weight. A significant difference was found between the two years in betalains content (80.0 ± 3.7 µg·mL−1 in 2022–2023 and 28.2 ± 2.5 µg·mL−1 in 2023–2024). The breakdown in the 2023–2024 season was likely due to the strong heat wave of July 2023 (up to 47 °C), which caused their partial degradation. In light of seasonal variability, this work provides some useful insights for future management of Cactus pear, also considering the possibility of usefully extending the period of cultivation and harvesting.

Horticulturae doi: 10.3390/horticulturae12040489

Authors: Anastasia Zolotukhina Svetlana Batashova Anastasia Guryleva Natalia Platonova Victoria Kunina Alexander Machikhin

Feijoa fruits are known for their pronounced post-harvest ripening. Phytopathogen-infected specimens pose a significant risk to storage stability and overall fruit quality. Early detection and removal of defective fruits during the initial storage stages are critical for maintaining market value and preventing the spread of disease. In this study, we analyze how the multispectral reflectance properties of the feijoa surface change in response to various defects. ‘Superba’ cultivar fruits were selected, including healthy controls and samples exhibiting bruises, anthracnose, stink bug damage, tissue suberization, and gray mold. Biochemical analyses were conducted to measure the levels of organic acids, sugars, ascorbic acid, and total polyphenols. Multispectral imaging was performed with a 12-channel camera operating in the 400–1000 nm wavelength range. Results showed that the fruits affected by gray mold had the lowest concentrations of malic and citric acids but the highest levels of succinic acid. Fruits with anthracnose or insect damage exhibited the highest sugar content. Distinct differences in spectral reflectance were observed between healthy and affected areas of fruit. Based on these findings, an image processing algorithm for defective fruit detection was developed.

Horticulturae doi: 10.3390/horticulturae12040488

Authors: Qinghai He Hongkai Shen Zhiyuan Liu Benxue Ma Yong He Zhi Lin Weihong Liu Pei Wang Xiaoli Li Peng Qi

As one of the six major traditional tea types in China, white tea’s quality formation is primarily influenced by the withering process. However, traditional methods for monitoring withering fail to achieve precise and stable control of moisture content. To address this issue, a total of 650 samples were collected at 13 withering time points (0–36 h), and the dataset was split into training and test sets at a 7:3 ratio. This study proposes a PRXBoost ensemble model for quantitative detection of withered white tea, which integrates data augmentation and intelligent algorithms. The ensemble model uses a Bagging-based weighted integration technique to combine Partial Least Squares Regression (PLSR), Ridge, and Extreme Gradient Boosting (XGBoost) models, and it conducts an in-depth analysis of the decision-making process within the PRXBoost model. First, the effectiveness of the data augmentation strategy and the superiority of the gradient descent algorithm are verified through pre-modeling based on the PLSR model and hyperparameter pre-search using the XGBoost model, respectively. Additionally, the Bayes algorithm is employed to optimize the weights of the sub-models, further enhancing the overall predictive performance. The results show that the PRXBoost model achieved the best performance among the compared models on the test set, with R2 = 0.854 and RMSE = 0.080, exceeding the highest R2 of a single model by 6%. These results indicate that PRXBoost provided improved predictive performance for moisture estimation within the current dataset. Finally, the SHapley Additive exPlanations (SHAP) algorithm is used to analyze the influence of each input feature on the prediction results, successfully identifying the 1916 nm and 1453 nm spectral bands as significant influencers of the prediction outcomes. These results suggest that the proposed model can support rapid, non-destructive monitoring of moisture evolution and provide actionable information for withering endpoint decision control.

Horticulturae doi: 10.3390/horticulturae12040487

Authors: Weiwei Zheng Mujun Huang Rongwen Wang Yanzun Cheng Di Pang Yunxiang Zang Bin Yu

Castanea henryi is one of the important fruit tree species cultivated in the mountainous regions of China. Castanea henryi is a starch-accumulating type. As an intracellular substance, starch plays an important role in maintaining cell turgor and sustaining fruit firmness. Although starch metabolism has been extensively studied in model and fruit crops, its regulatory mechanisms in Castanea henryi remain poorly understood. This review synthesizes recent advances in starch physicochemical properties, metabolic pathways, and regulatory mechanisms during fruit development, seed germination, and postharvest storage. Current knowledge gaps, including limited molecular characterization and gene functional analysis in Castanea henryi, are highlighted. This review provides a framework for future research and breeding strategies aimed at improving fruit quality and storage performance.

Horticulturae doi: 10.3390/horticulturae12040486

Authors: Jiapeng Sun Yucheng Peng Zhimeng Zhang Wenrui Xu Boyuan Xi Yuanying Zhang Yihong Song

Aimed at the practical challenge that pest occurrence in fruit and vegetable horticultural production exhibits strong environmental dependency, pronounced stage characteristics, and high sensitivity to control decision-making, a multimodal pest recognition and occurrence risk joint modeling method is proposed to address the limitation that conventional intelligent plant protection systems focus primarily on pest identification while lacking risk discrimination capability. Within a unified network framework, pest visual information and environmental temporal data are integrated through the construction of an environment-guided representation learning mechanism, a recognition–risk joint optimization strategy, and a risk-aware decision representation modeling structure. In this manner, pest category recognition and occurrence risk evaluation are conducted simultaneously, thereby providing direct decision support for precision prevention and control in fruit and vegetable production. Systematic experimental evaluation is conducted based on multi-crop and multi-year field data collected from Wuyuan County, Bayannur City, Inner Mongolia. Overall comparative results demonstrate that an identification accuracy of 0.947, a precision of 0.936, and a recall of 0.924 are achieved on the test set, all of which significantly outperform mainstream visual detection models such as YOLOv8, DETR, and Mask R-CNN. In terms of detection performance, mAP@50 and mAP@75 reach 0.962 and 0.821, respectively, indicating stable localization and discrimination capability under complex backgrounds and dense small-target conditions. For the occurrence risk discrimination task, a risk accuracy of 0.887 is obtained, representing an improvement of approximately 4.5 percentage points compared with the simple multimodal feature concatenation method. Cross-crop, cross-site, and cross-year generalization experiments further show that risk accuracy remains above 0.84 with stable recognition performance under significant distribution shifts. Ablation studies verify the synergistic contributions of the proposed core modules to overall performance improvement. The results indicate that the proposed framework enables the transition from single recognition to risk-driven plant protection decision-making, providing a technically viable pathway for pest diagnosis and control strategy optimization in fruit and vegetable horticulture.

Horticulturae doi: 10.3390/horticulturae12040485

Authors: Miyun Jiao Yueren Xiao Kexin Liu Huixin Gang Junwei Huo Dong Qin

The ripe fruits of blackcurrant (Ribes nigrum L.) are rich in vitamin C, anthocyanins, and flavonoids. Besides being consumed fresh, the fruits can be processed into fruit juices, jams, wines, and other products, exhibiting considerable economic and nutritional value. Flavonoids are a class of important plant secondary metabolites with antioxidant, anti-inflammatory, and anti-cancer properties. Although previous studies have confirmed the involvement of multiple structural genes and transcription factors in flavonoid biosynthesis, the specific role of the dihydroflavonol 4-reductase (DFR) gene in regulating flavonoid accumulation during fruit development of blackcurrant remains to be clearly elucidated. In this study, we identified an RnDFR gene located in the nucleus and cytoplasm, which has the same expression trend as flavonoid content in fruit development stages. Overexpression of RnDFR improved the flavonoid accumulation and upregulated the expression levels of related structural genes (4CL, CHS, LDOX, ANR, and UFGT) in tomato. Transiently overexpressing RnDFR in blackcurrant fruit also increased the content of flavonoids and DFR enzyme activity, whereas silencing RnDFR resulted in the opposite effect. In addition, overexpression of RnDFR in tomato seedlings improved cold and drought tolerance by increasing flavonoid accumulation, reducing membrane lipid peroxidation damage and enhancing the activities of antioxidant enzymes. This study systematically reveals the key role of RnDFR in flavonoid biosynthesis and the enhancement of cold and drought tolerance, and offers an important theoretical basis for future efforts to optimize flavonoid content in blackcurrant and improve fruit nutritional quality.

Horticulturae doi: 10.3390/horticulturae12040484

Authors: Daniil N. Olennikov Nina I. Kashchenko Nadezhda K. Chirikova

Rhododendron adamsii Rehder, also known as sagan dali, is one of the most valued northern rhododendron species of Siberia and Mongolia as both a medicinal and food plant. Its flowers are traditionally used by indigenous communities in daily life to prepare teas that are attributed with medicinal properties in local traditional medicine. However, the lack of reliable data on the chemical composition and bioactivity of R. adamsii flowers has limited their broader application and underscores the need for comprehensive studies to verify their beneficial properties. The application of liquid chromatography–mass spectrometry enabled the identification of fifty-four compounds in sixteen samples of different origins, with flavonoids representing the dominant group and belonging to various aglycone types. Among the identified metabolites were dihydroflavonols of the taxifolin series; flavonols of the myricetin, quercetin, and kaempferol series; as well as several minor flavonoid and non-flavonoid compounds. Thirty-seven of these compounds are reported for the first time in this species. The total phenolic content in R. adamsii flowers can reach 155.82 mg/g, of which up to 147.54 mg/g are flavonoids. The analysis revealed variation in both the qualitative profile and quantitative levels of individual compounds among different populations, suggesting the presence of distinct R. adamsii chemotypes. The preparation of flower tea was associated with high rates of flavonoid transfer into the decoction, particularly when pulverized raw material was used compared with unground or hand-ground samples. This was reflected in the enhanced antioxidant activity of the decoctions, which was maximal for pulverized flowers in in vitro assays against artificial and natural free radicals, as well as in nitric oxide scavenging and Fe2+-chelating tests. These results suggest that R. adamsii flowers and their tea represent a new possible source of flavonoids and after additional clinical evidence may serve as valuable antioxidant ingredients for the development of functional foods.

Horticulturae doi: 10.3390/horticulturae12040483

Authors: Hathairut Jindamol Akira Thongtip Cattarin Theerawitaya Suriyan Cha-um Praderm Wanichananan Kriengkrai Mosaleeyanon Panita Chutimanukul

Holy basil (Ocimum tenuiflorum L.) is an extensively utilized herb, encompassing numerous bioactive compounds that hold significant interest in the food and pharmaceutical industries. High-throughput phenotyping is a rapid and non-invasive technique, providing diverse phenotypic trait observation and measurement. However, basic knowledge regarding the diversity among varieties beneficial for large-scale production in terms of yield and secondary metabolites under a controlled greenhouse environment is limited. Hence, we assessed and classified 12 Thai accessions and two commercial cultivars by evaluating growth, yield, and secondary metabolites at each harvesting time using an advanced NSTDA-Plant Phenomics platform. Notably, accessions OC130, OC141, OC072, and OC059 demonstrated stable metabolite production and antioxidant activity, highlighting their potential as superior accessions for further cultivation and utilization. These findings underscore the potential for tailored cultivation practices to manipulate secondary metabolite synthesis, thereby enhancing the medicinal properties and market value of Thai holy basil. The implications of this study extend to farmers, providing valuable insights into the phenotypic variation and practical avenues under consistent environmental conditions. Breeders can observe genetic diversity to improve basil varieties with desirable traits for specific environmental niches. Moreover, modern agricultural practices can benefit from understanding the impact of controlled environments on secondary metabolite synthesis.

Horticulturae doi: 10.3390/horticulturae12040482

Authors: Hend Askri Sywar Haffani Hager Snoussi Rim Zitouna-Chebbi Tarek Fezzani Asma Najar Ronny Berndtsson

Citrus production is increasingly constrained worldwide by rising soil salinity, particularly in arid and semi-arid regions. In Tunisia, the expansion of saline soils represents a major abiotic stress limiting orchard productivity. The identification of salt-tolerant rootstocks has therefore become a priority, especially as alternatives to sour orange (SO, Citrus aurantium L.), which is highly susceptible to Citrus tristeza virus. In recent years, several outbreaks of the disease have been reported in the Cap Bon citrus-growing region, posing an imminent threat to the sustainability of citrus production in Tunisia. This study evaluated the salt tolerance of commercial cultivars (HER, MAR, WN, NH) grafted onto Citrus volkameriana Ten. & Pasq. (CV, Citrus aurantium × Citrus limon (L.) Burm.f.) and three Poncirus trifoliata hybrids (CC, C35, CTR) under irrigation water salinity ranging from 1.1 to 4.1 mS/cm and soil salinity between 1.8 and 3.8 mS/cm. Data were collected between 2020 and 2021 in five young citrus orchards (KHB, OSN, BKN, BSJ, CHK) located in the main citrus-producing region of Tunisia, with key physiological measurements conducted during the high-evaporation period. Salinity increased across most sites during summer 2021, affecting ion homeostasis, Na+/K+ selectivity, stomatal traits, photosynthetic performance, and growth. The highest leaf Cl− concentration (0.4 meq g−1 dry weight) was recorded in the sensitive HER/CC combination at the OSN site. Increased salinity at OSN was associated with a 0.86% reduction in canopy growth compared to BSJ. Rootstock tolerance was strongly linked to the ability to restrict Cl− accumulation in leaf tissues. Under higher salinity conditions, CV showed superior performance and represents a suitable alternative to SO.

Horticulturae doi: 10.3390/horticulturae12040481

Authors: Alfonso Morillo-De los Santos Rosalba Rodríguez-Peña Maria Cristina Suarez Marte Maria Serrano Daniel Valero Juan Miguel Valverde Domingo Martínez-Romero

Monitoring avocado (Persea americana Mill., cv. Semil-34) in tropical mountain landscapes of Cambita, San Cristóbal, Dominican Republic is inherently complex due to the pronounced topographical and climatic heterogeneity that modulates the crop’s ecophysiological responses, specifically vegetative vigor, carbon allocation, and the synchronization of reproductive flushes. This study integrates 5-year (2020–2025) Sentinel-2 time series, ERA5-Land climatic variables (air temperature, total precipitation, and radiation), and geomorphometric covariates to explain variability in yield and fruit quality. Multispectral indices, including the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Normalized Difference Red Edge (NDRE), and Normalized Difference Moisture Index (NDMI), were analyzed using Partial Least Squares Regression (PLSR) to characterize phenological dynamics and rank dominant predictors. The results revealed coherent spectral phenological trajectories; however, a significant inverse relationship was detected between canopy vigor and yield during reproductive phases. High vegetation index values were significantly and negatively associated with lower production (r = −0.58, p < 0.0021), reflecting a potential source–sink imbalance. Topography functioned as a structural filter, regulating root drainage and productive stability across the landscape. While yield variability was partially explainable (R2 = 0.38), internal fruit quality, measured as dry matter content, exhibited comparatively high environmental stability. A central contribution of this research lies in identifying the “vigor paradox” in cv. Semil-34 and the suggestion that topography may exert a stronger influence than direct spectral signals under tropical hillside conditions. These findings provide an exploratory framework for anticipating yield and fruit quality through satellite remote sensing or UAVs, supporting site-specific management decisions in mountain agricultural systems.

Horticulturae doi: 10.3390/horticulturae12040480

Authors: Ting Sang Dongyan Yang Dan Wang Huiwan Wang

To enhance the benefits and ecological safety of tomato residue retention, this study evaluated the regulatory effects of conventional ambient temperature retention (CR) and solar high-temperature retention (TR) on the initial soil environment and rhizosphere microecology of subsequent crops (continuous tomato and rotational cucumber). The results showed that CR promoted the accumulation of humic acid and increased the contents of phenolic acids and small-molecule organic acids in the soil. TR also increased small-molecule organic acids but primarily enriched fulvic acid, accompanied by higher concentrations of phenolic acids. Regarding microecological responses, CR enriched potential plant-growth-promoting bacteria (Pseudomonas, Sphingomonas, Lysobacter) in the rhizosphere, but it also increased the relative abundance of the potential pathogen Fusarium. In contrast, TR promoted the colonization of heat-tolerant beneficial biocontrol microbes (Bacillus, Chaetomium, Mycothermus), with no Fusarium enrichment observed. Redundancy analysis and Mantel tests revealed that the changes in soil nutrients and organic acid fractions induced by residue retention were correlated with the succession of the rhizosphere microbial community and the reconstruction of the metabolic profile. This study demonstrates that TR can effectively mitigate the risk of pathogen enrichment associated with ambient temperature retention, constructing a potentially disease-suppressive initial microecological environment for subsequent crops.

Horticulturae doi: 10.3390/horticulturae12040479

Authors: Fangzheng Dai Tengfei Zhou Xiaobin Wang Bin Zhou Jiaxuan Li Huibin Han Yudi Gan Jianping Liu Youxin Yang

Cowpea (Vigna unguiculata L. Walp.) is an important legume crop contributing to food and nutritional security. However, its systematic evaluation for yield and adaptability, particularly in the Middle-Lower Yangtze River region of China, remains insufficient. In this study, conducted in Jiangxi Province across two seasons (April and August 2024), a comprehensive analytic hierarchy process (AHP) model evaluated 139 Chinese cowpea accessions based on 18 agronomic traits. The evaluation showed coefficients of variation for 11 quantitative traits ranged from 5.18% to 49.42%, with single pod weight and pod length exhibiting the highest variation. Shannon–Wiener index analysis indicated pod width and SPAD (Soil Plant Analysis Development) were the most diverse traits (H′ = 1.04 and 1.01). Based on the AHP model, 139 accessions were classified into four grades. Notably, Grade I accessions demonstrated high comprehensive scores, comprising three cultivars: ‘Changde Baipi Doujiao’, ‘Guilin Changjiangdou’, and ‘Guangrao Wuyuemang’. These exhibit promising performance under field conditions and high yield potential, making them worthy of further regional testing. Cluster and principal component analyses revealed natural groupings and variation patterns within the germplasm resources. This study provides a practical, preliminary decision-support tool for yield and field adaptation evaluation.

Horticulturae doi: 10.3390/horticulturae12040478

Authors: Yaling Li Dandan Huang Shuhua Zhu

Strontium (Sr) is an essential trace element that plays a critical role in bone health, calcium absorption, cardiovascular function, and nerve function. In this experiment, fresh-cut peaches were treated with different concentrations of strontium chloride (SrCl2) to study the effects of SrCl2 on the antioxidant system, endogenous nitric oxide (NO) metabolism, and endogenous hydrogen sulfide (H2S) metabolism, aiming to investigate the regulatory mechanism of Sr on postharvest quality of horticultural products. The results showed that, compared with the control, 320 μM SrCl2 significantly suppressed the respiration rate by 15.10% and delayed the respiratory peak by 2 days. Meanwhile, SrCl2 treatment effectively inhibited the rise in electrolyte leakage (EL), color difference, and weight loss, and delayed the decline in fruit firmness. In addition, SrCl2 treatment significantly up-regulated the gene expression levels and enzyme activities of the antioxidant system, the AsA-GSH cycle, NO, and H2S metabolism, which reduced the loss of antioxidants, enhanced the ability of fruits to scavenge hydrogen peroxide (H2O2), hydroxyl radical (˙OH), and superoxide anion (O2−˙), and lowered the malondialdehyde (MDA) content. It suggests that SrCl2 treatment has a positive effect on maintaining the postharvest quality of fresh-cut peaches, which appears to be associated with increased endogenous production of NO and H2S, thereby enhancing antioxidant system activity.

Horticulturae doi: 10.3390/horticulturae12040477

Authors: Shun-Hua Zhu Xiu-Lai Zhong Jun Yan Ai-Sheng Xiong Qian Qiu Qing Luo Cong-Yin Cheng Guo-Fei Tan

Oenanthe javanica (LY) and Oenanthe linearis (SQ), collectively known as water dropwort, are popular aquatic vegetables in China. Their blanching cultivation produces tender, etiolated tissues with reduced lignin content and improved sensory qualities. To clarify the effects of shading cultivation on lignin synthesis and accumulation in these two cultivars, this study investigated their shading responses in terms of morphological traits, physiological indices, enzyme activities, cellular structure, and lignin synthesis-related gene expression levels. The results showed significant differences between the two cultivars during the 24-day shading treatment. Compared with ‘SQ’, ‘LY’ exhibited upright growth and marked elongation of new petioles, while old petioles were significantly decreased. The entire plant turned light yellow or white, conferring commercial value typical of blanched water dropwort. During the initial 0–16 d of shading, lignin content was higher in ‘SQ’; however, by day 24, it was 92.26 mg·g−1 lower in ‘SQ’ than in ‘LY’. In terms of enzyme activity, shading generally decreased the activities of PAL, CAD, and C4H, while increasing 4CL activity. Notably, shading reduced POD activity in ‘SQ’ but increased it in ‘LY’. Histological observation revealed that shading led to a gradual loosening of xylem cell arrangement in water dropwort; furthermore, the number and size of xylem cells in ‘LY’ were significantly larger than those in ‘SQ’. At the molecular level, shading significantly downregulated the expression of OlPAL, Ol4CL, OlCCR, OlCCoAOMT, and OlCAD1 in ‘SQ’, a trend that correlated with the observed decrease in lignin content and thus appears to be a primary cause of altered lignin accumulation. In ‘LY’, the expression level of OjPAL2 decreased, showing a positive correlation with both PAL enzyme activity and lignin content, suggesting it acts as a key regulator of lignin synthesis under these conditions. In conclusion, compared with ‘SQ’, ‘LY’ exhibits a higher degree of lignification but possesses stronger resistance to shading stress, making it more suitable for producing high-quality etiolated water dropwort.

Horticulturae doi: 10.3390/horticulturae12040476

Authors: Josinaldo Lopes Araújo Rocha Márcia Michelle de Queiroz Ambrósio Railene Hérica Carlos Rocha Araújo

Horticulture is an activity with a colossal economic and social impact worldwide due to its potential to generate employment and income—particularly due to the significant labor demand throughout its production chain—and its contribution to food security and the fight against hunger, challenges intensified by population growth and climate change [...]

Horticulturae doi: 10.3390/horticulturae12040475

Authors: Ricardo Salomón-Torres Mohammed Aziz Elhoumaizi Glenn C. Wright Abdelouahhab Alboukhari Zaid Yohandri Ruisanchez-Ortega Fidel Núñez-Ramírez Laura Samaniego-Sandoval

Date palm (Phoenix dactylifera L.) production relies on the availability of viable and physiologically active pollen during female flowering, making pollen storage an important strategy to overcome flowering asynchrony and ensure effective artificial pollination. In this study, we systematically reviewed and quantitatively synthesized the effects of pollen storage conditions on pollen physiological quality and reproductive performance in date palm. Following PRISMA guidelines, 22 experimental studies were identified in the qualitative synthesis, and comparable quantitative datasets were used for meta-analysis. Acetocarmine staining, the most commonly used method for assessing pollen stainability across studies, was selected as the standardized indicator of pollen stainability. Multilevel random-effects meta-regression models were applied to evaluate temporal deterioration patterns over storage periods of up to 24 months, while standardized forest plot meta-analyses were used to estimate pooled effects after 12 months of storage. The results revealed a strong temperature-dependent decline in pollen physiological quality. Acetocarmine stainability declined by −6.41, −3.10, −2.62, and −2.24% month−1 under ambient, refrigerated, mild freezing, and moderate freezing conditions, respectively, whereas germination declined by −6.77, −1.86, −3.14, −1.09, and −1.05% month−1 under ambient (23–25 °C), refrigerated (4–5 °C), mild freezing (−5 °C), moderate freezing (−20 °C), and deep freezing (−80 °C) conditions, respectively. After 12 months of storage, stainability, germination, and fruit set were significantly reduced relative to fresh pollen. In contrast, pollen storage had no significant effect on final fruit weight, suggesting that pollen deterioration primarily affects fertilization success rather than subsequent fruit development. The available evidence suggests that low-temperature storage represents the most effective strategy for preserving date palm pollen functionality. Refrigerated storage around 4 °C appears to provide a reliable and accessible option for short- to medium-term pollen preservation, whereas freezing conditions may be advantageous for longer storage periods when moisture control and thawing procedures are properly managed.

Horticulturae doi: 10.3390/horticulturae12040474

Authors: Anderson Rodrigo Luciano da Silva Jéssica Crhistie de Castro Granjeiro Oliveira Fred Augusto Lourêdo de Brito Fabiana Barbosa do Nascimento Raíres Irlenízia da Silva Freire Alex Lázaro de Sousa Nogueira Wedson Aleff Oliveira da Silva Sarah Alencar de Sá David Geidson Moreira Ramos Naama Jéssica de Assis Melo Patrícia Ligia Dantas de Morais Vander Mendonça Ivanice da Silva Santos Valécia Nogueira Santos e Silva João Everthon da Silva Ribeiro Adriano do Nascimento Simões

Pitaya is a high-value tropical fruit with a postharvest life constrained by rapid physiological deterioration. This study aimed to evaluate the efficacy of chitosan-based (CH) biopolymeric coatings, enriched with ascorbic acid (AA), on the postharvest quality and preservation of pitaya fruits stored under refrigeration (12 °C). The fruits were subjected to different treatments and evaluated for biometric and physicochemical parameters, including weight loss, total soluble solids, pH, titratable acidity, and the SS/TA ratio throughout storage. The results demonstrated that the coatings significantly reduced weight loss (e.g., 4.15% for the CH4AA treatment) and contributed to the maintenance of quality attributes, delaying senescence-associated processes. Among the treatments, the combination of chitosan with ascorbic acid was the most effective in preserving fruit quality, extending the marketable shelf life from 10 to 20 days. These findings indicate that the use of biopolymeric coatings is a promising strategy to prolong the shelf life and maintain the postharvest quality of pitaya, with potential applications in commercial supply chains.

Horticulturae doi: 10.3390/horticulturae12040473

Authors: Xiaomei Song Ningqi Wang Yuyi Zhang Xudong He Nan Guo Jun Tao

Cadmium (Cd) is a major environmental pollutant due to its high mobility and persistence in soils, facilitating entry into the food chain and threatening ecosystems and human health. However, the mechanisms that enable Salix species, well adapted for Cd remediation, to both tolerate and accumulate Cd remain elusive. Here, two Salix genotypes with contrasting Cd tolerance were examined under control and Cd stress using integrated physiological, transcriptomic, and metabolomic analyses of roots and leaves. The Cd-tolerant genotype (Salix suchowensis P294) maintained biomass under Cd stress, whereas the Cd-sensitive genotype (Salix sinopurpurea × Salix integra P646) showed a ~17% reduction. P294 accumulated more Cd in its stems (132.76 mg kg−1) and leaves (122.25 mg kg−1) than P646 (93.54 and 56.24 mg kg−1). Transcriptomics responses were stronger in roots, with 896 DEGs in P294 and 462 in P646, enriched in nitrogen metabolism, phenylpropanoid biosynthesis, and metal transport, whereas only 167 and 176 DEGs were detected in leaves for P294 and P646, respectively. Metabolomics revealed more altered metabolites in roots (125 in P294, 89 in P646), mainly organic acids, amino acids, and flavonoids, compared with leaves (46 and 66). RT-qPCR validated the root-specific upregulation of key detoxification and transport genes (ABCA7, PRX72, GSTU1, GSTU4, ZIP1). These results reveal a root-centered regulatory network underlying Cd accumulation and tolerance, integrating detoxification, redox homeostasis, and structural reinforcement, as well as providing valuable targets for genetic improvement of phytoremediation efficiency.

Horticulturae doi: 10.3390/horticulturae12040472

Authors: Yusuf Güvenaltın Melek Demirel Halil Samet Mehmet Ufuk Kasım Rezzan Kasım

Salinity is a major constraint for lettuce production, affecting plant growth, physiological status, and market quality. This study evaluated the combined effects of increasing salinity levels (S0: non-saline control; S30, S60, and S120 mM NaCl) and Trichoderma harzianum inoculation on morphological, physiological, and quality-related traits of lettuce. Increasing salinity levels resulted in significant reductions in growth-related parameters, particularly leaf area, shoot biomass, root volume, and cutting resistance (CR), with the most pronounced decreases observed at S120. In contrast, several physiological and quality-related parameters showed different response patterns. Membrane stability index (MSI) and chlorophyll index remained relatively stable across salinity treatments, while total soluble solids (C) increased with increasing salinity, indicating osmotic adjustment under stress conditions. Leaf color parameters showed reductions in lightness and chroma at higher salinity levels, suggesting structural and optical changes in leaves rather than severe pigment degradation. The effects of Trichoderma on plant growth were limited and did not consistently mitigate growth reductions under salinity. However, inoculation influenced several physiological and quality-related traits, including MSI and TSS, indicating a role in physiological regulation and stress adaptation rather than direct growth promotion. Multivariate analyses indicated that salinity was the main factor contributing to treatment separation, whereas Trichoderma application influenced the overall trait profile without consistently increasing growth parameters. Overall, the results suggest that under saline conditions, Trichoderma may contribute to stress tolerance and physiological stability rather than directly increasing plant growth, and its effectiveness depends on stress severity.

Horticulturae doi: 10.3390/horticulturae12040471

Authors: Cecilia Beatriz Peña-Valdivia Victor Baruch Arroyo-Peña Rodolfo García-Nava José Luis Salinas Morales

Plants of the genus Opuntia are cacti that grow under natural conditions, with scarce humidity, drastic changes in daytime and nighttime temperatures, and poor soils. Their fruits are a food source in certain regions of the world, and their modified stems (cladodes) have diverse uses, including human consumption—especially when young, tender, and succulent (“nopalitos”) —livestock feed, and raw material for various products. There are approximately 300 species and dozens of variants of this genus, identified as wild, semi-domesticated, or domesticated. The physiological and biochemical responses to abiotic stress in these species are diverse but are related to their Crassulacean acid metabolism and the level of domestication. The morphological modifications in fruits, seeds, and cladodes of the genus Opuntia during domestication appear to be the sum of numerous significant biochemical-physiological changes, but generally of small magnitude. Thus, evaluating wild, semi-domesticated, and domesticated Opuntia species allows us to understand the physiological and biochemical processes along a natural gradient (original and modified by natural and artificial selection and by the cultivation environment) and their alteration by abiotic stress of any kind. This review summarizes our main advances in considering the genus Opuntia as a model for evaluating abiotic stress in the physiology and biochemistry of succulent plants. Furthermore, it shows high relevance, especially in the context of climate change, because Opuntia species are key to food security in arid zones.

Horticulturae doi: 10.3390/horticulturae12040470

Authors: Csilla Tóth Enikő Bodó Szabolcs Vigh Brigitta Tóth

The effects of progressive drought stress were examined in four economically important plant species belonging to the Lamiaceae family: catnip (Nepeta cataria L.), lavender (Lavandula angustifolia Mill.), holy basil (Ocimum tenuiflorum L.), and perilla mint (Perilla frutescens (L.) Britton). Plants were grown in a controlled pot experiment under three soil water capacity levels: 70% (control), 50% (moderate stress), and 30% (severe stress), and the drought stress lasted for 30 days. The study evaluated a comprehensive set of leaf micromorphological parameters, including the density and diameter of glandular trichomes, stomatal density and size, and the thickness of the lamina, mesophyll, epidermis, cuticle, and parenchymal layers. In addition, essential oil (EO) content, total flavonoid content (TFC), and elemental composition were analyzed. Drought responses were strongly species-specific. O. tenuiflorum, P. frutescens, and N. cataria showed high sensitivity characterized by reduced biomass and thinning of leaf tissues. These changes were accompanied by typical xeromorphic adaptations, such as increased stomatal and glandular trichome density, and reduced stomatal size. L. angustifolia exhibited pronounced cuticle thickening, suggesting an effective structural mechanism to minimize water loss. Secondary metabolism also responded differently among species. In some cases, drought shifted metabolic allocation toward flavonoid accumulation at the expense of essential oils, whereas in others, moderate stress promoted the co-accumulation of both compounds. These patterns indicate distinct adaptive strategies linking anatomical plasticity with metabolic regulation. Overall, moderate drought supported adaptive responses, while severe water limitation impaired growth and metabolic production. From a practical perspective, maintaining moderate soil water availability appears critical to optimize both plant performance and the accumulation of valuable secondary metabolites in Lamiaceae species.

Horticulturae doi: 10.3390/horticulturae12040469

Authors: Xiuping Tu Shuya Zhang Yun Dai Ze Li Shujiang Zhang Shifan Zhang Hui Zhang Rifei Sun Guoliang Li Fei Li

Leaf-color variation in plants should be associated with chlorophyll metabolism and chloroplast development. Here, we characterized a low-temperature-sensitive pakchoi DH line, 1197, which exhibited green leaves at 25 °C, but showed yellowing at 4 °C. Low temperature significantly reduced chlorophyll accumulation and disrupted chloroplast ultrastructure. After transfer from 4 °C to 25 °C for 7 days, yellow leaves partially regreened, and chlorophyll a content increased by 366.67%. RNA-seq analysis identified 3058 core DEGs associated with the yellowing–regreening transition, which were significantly enriched in photosynthesis–antenna proteins, photosynthesis, and porphyrin metabolism pathways. Leaf yellowing was characterized by repression of chlorophyll biosynthesis genes (e.g., CHLD, CHLM, PORC) and induction of degradation genes (SGR1, SGR2, NYC1, PAO), together with widespread downregulation of chloroplast function-related genes. In addition, GLK2, HBI1, NAC047, and NAC029 were identified as candidate regulators of temperature-dependent leaf-color conversion. This study provides candidate molecular insights into low-temperature-induced yellowing and regreening in pakchoi and offers candidate genes for future functional validation and Brassica breeding.

Horticulturae doi: 10.3390/horticulturae12040468

Authors: Juan Luo Yao Li Fengxia Shao Sen Wang Kuo Yang Tian Xiang Xuanyu Zhang Yutong Li Xinxin Lian Minhuan Zhang Yafeng Wen Saiyang Zhang

Nai plum (Prunus salicina Lindl. var. cordata) is a high-value fruit crop in southern China, yet its post-harvest quality is often compromised by fruit browning, a major constraint to storage and marketability. Addressing this challenge requires a deeper understanding of the species’ reproductive biology, which underpins both fruit set and cultivar improvement. In this study, we characterized the flowering biological characteristics of Nai plum accessions introduced from Yanling and Liuyang (Hunan Province) and Shaoguan and Lechang (Guangdong Province). Using field observations combined with microscopic and submicroscopic techniques, we documented flowering phenology, flowering dynamics, floral organ traits, pollen viability and stigma receptivity. The flowering period was in March, lasting 26–28 d, and the group blooming period was divided into three stages: Initial opening stage, Full blooming stage, and Final flowering stage. The single-flower opening process was divided into eight stages. Pollen viability followed a unimodal curve, peaking at the petal flattening stage (PF) across all accessions, though peak values varied by provenances. Stigmas were of the wet type, with receptivity following a weak–strong–weak pattern; peak receptivity occurred at early flowering (EF) and PF in most accessions. The EF of Nai plum from Yangling (S1) lasted for 7 h, and PF lasts for 28 h. The EF of Nai plum from Yangling (S2) lasted for 3 h, and the PF lasted for 11 h. Both the EF and the PF of Nai plum from Shaoguan (S3) lasted for 14 h. The bud white stage (BW) of Nai plum from Lechang (S4) lasted for 6 h and the EF lasted for 7 h. The EF of Nai plum from Liuyang (S5) lasts for 7 h, and the PF lasted for 28 h. These findings clarify the reproductive phenology and floral biology of Nai plum, providing foundational knowledge that can inform breeding strategies and cultivation practices aimed at improving fruit set and, ultimately, post-harvest quality.

Horticulturae doi: 10.3390/horticulturae12040467

Authors: Neil Uy Sang-Yun Lee Reyna Sanchez Chung-Ho Choi Sanghyun Lee

Allium longistylum is a relatively understudied species whose phytochemical composition and biological activities remain largely unexplored. In this study, the first true leaf (FTL) and the second true leaf (STL) of A. longistylum were compared with respect to phenolic composition, antioxidant capacity, antimicrobial activity, and quorum-sensing (QS) inhibition. Total phenolic content (TPC) and total flavonoid content (TFC) were determined spectrophotometrically, while antioxidant activity was evaluated using ABTS and DPPH radical scavenging assays. Antimicrobial and anti-QS activities were assessed against Staphylococcus aureus, Acinetobacter baumannii, and Chromobacterium violaceum. STL exhibited significantly higher TPC and TFC than FTL, consistent with its stronger radical scavenging activity. Both extracts showed moderate antimicrobial activity and reduced violacein production in C. violaceum, indicating interference with QS. UPLC-Q-Orbitrap-ESI-MS/MS profiling tentatively identified several phenolic acids and flavonoid derivatives. HPLC analysis confirmed the presence of selected phenolic compounds, although several prominent peaks in the chromatograms remained unidentified. Many of the compounds detected by UPLC-Q-Orbitrap-ESI-MS/MS and HPLC have previously been reported to exhibit antioxidant, antimicrobial, and anti-QS activities; their presence may therefore contribute to the bioactivities observed in both extracts. However, their contribution to the observed effects remains speculative and requires further validation through targeted isolation and bioactivity testing. The results suggest that A. longistylum is a promising source of phenolic compounds with antioxidant and antimicrobial properties.

Horticulturae doi: 10.3390/horticulturae12040466

Authors: Yaxin Liu Zemei Li Fuyuan Lu Liangrui Yang Lishan Liu Zhen Tian Jinmin Zhou Siyi Ge Xuewei Wu

Background: Konjac (Amorphophallus spp.) is an economically important crop valued for the glucomannan content in its corms. Currently, the konjac industry faces germplasm degeneration due to long-term asexual propagation. Developing tissue culture and genetic transformation techniques is essential for its genetic improvement. The WUSCHEL-related homeobox (WOX) transcription factors are critical regulators of somatic embryogenesis and stem cell maintenance in plants. Methods: In this study, we performed genome-wide identification and characterization of WOX genes in the A. konjac reference genome. Furthermore, comparative transcriptomic analyses and functional verification were conducted in A. bulbifer. Results: A total of 12 AkWOX genes were identified in A. konjac, and their structural features were documented. Comparative transcriptomic analysis of A. bulbifer revealed that AbWOX genes were differentially expressed between embryogenic calli (EC) and non-embryogenic calli (nEC). Notably, AbWOX2 was significantly upregulated in EC. Overexpression of AbWOX2 significantly promoted callus proliferation and shoot regeneration in A. bulbifer. Furthermore, AbWOX2-overexpressing lines exhibited a 5.3-fold increase in genetic transformation efficiency (from 5.12% to 27.31%) compared to the control. Conclusions: We characterized the diverse expression patterns of the WOX gene family in Amorphophallus. Crucially, we identified specific individual members—most notably the markedly upregulated AbWOX2—that function as pivotal drivers of somatic embryogenesis and serve as promising candidates for enhancing regeneration and genetic engineering efficiency in Amorphophallus species.

Horticulturae doi: 10.3390/horticulturae12040465

Authors: Yuying Cui Rui Ma Yin Wu Mengwen Lyu Yali Zhang Yani Wu

This study aimed to provide a comprehensive characterization of floral volatile organic compounds (VOCs), perform systematic comparative analysis among multiple fragrant camellias, and establish a classification framework based on aroma components for cultivars derived from Camellia Sect. Theopsis. Volatile compounds were analyzed from 21 fragrant camellias using headspace solid-phase microextraction coupled with gas chromatography–time-of-flight mass spectrometry (HS-SPME-GC-TOFMS), followed by cluster and correlation analyses. A total of 51 volatile compounds were identified, including 20 alcohols, 15 aldehydes, and five esters, among which 27 were designated as major aroma components. Alcohols were the dominant class, and phenylethyl alcohol was detected in all cultivars, with a relative abundance ranging from 1.30% to 45.86%. Certain compounds, such as eugenol and 2-pentylfuran, exhibited cultivar-specific enrichment. Cluster analysis revealed a high degree of similarity in volatile profiles, with the strongest correlation observed between Camellia ‘Himenoka’ and Camellia ‘Minato-no-haru’ (r = 0.97). This similarity may be associated with a shared parental background, particularly the frequent use of Camellia lutchuensis in breeding. These findings provide a systematic understanding of floral VOC composition and offer a chemical basis for the utilization of Camellia Sect. Theopsis germplasm in fragrance-oriented breeding.

Horticulturae doi: 10.3390/horticulturae12040464

Authors: Tianyu Liu Zelong Liu Jianmin Wang Dongxin Guo Yuxuan Tan Ping Jiang

To address the challenges of unstable target localization and poor multi-module coordination in automated green pepper harvesting—caused by occlusions from branches and leaves, as well as varying lighting conditions—this paper presents the design and implementation of a modular robotic picking system. At the perception level, the system integrates a YOLOv8 detector with a RealSense D435i camera to identify and locate the calyx–ectocarp junctions of green peppers. An integrated multi-target tracking and filtering framework is proposed, which fuses multi-feature association, trajectory smoothing and coordinate denoising strategies to suppress depth noise and trajectory jitter, thereby enhancing the stability and accuracy of 3D localization. At the control and execution level, a depth-first picking sequence strategy with ID freeze-state management is implemented within a multithreaded software–hardware co-design architecture. This approach avoids task conflicts and duplicate operations while supporting continuous multi-fruit harvesting. Field experiments under natural outdoor lighting and varying occlusion levels demonstrate that the proposed system achieves recognition rates of 91.57% and 80.29% and harvesting success rates of 82.85% and 77.68% for non-occluded and lightly occluded fruits, respectively. The average picking cycle per pepper fruit is 9.8 s. This system provides an effective technical solution for addressing stability control challenges in the automated harvesting process of green peppers.

Horticulturae doi: 10.3390/horticulturae12040463

Authors: Huai-Na Gao Yu-Feng Zhang Shu Chen Si-Ji Fang Rui-Han Qi Cheng-Lin Liang Shun-Feng Ge Yan-Hui Lv Shang Wu Ya-Li Zhang Han Jiang Yuan-Yuan Li

Apple (Malus domestica Borkh.) is the most widely cultivated deciduous fruit tree with the largest industrial scale and the highest economic value in China. Fruit surface glossiness and plant stress tolerance are two core traits that determine the economic benefits and sustainable development of the apple industry. The plant epidermal cuticle is not only the core material basis for determining fruit glossiness but also the first barrier for plants to resist abiotic and biotic stresses. Glycosylphosphatidylinositol-anchored lipid transfer proteins (LTPGs) are the core functional factors mediating trans-cell wall lipid transport in plants. At present, the functions and action mechanisms of LTPG family members that simultaneously regulate fruit appearance quality and stress tolerance in apple remain largely unclear. In this study, we took the MdLTPG17 gene as the research object, clarified its biological function of stress resistance under drought stress, and dissected the molecular mechanism by which it mediates fruit glossiness formation via regulating fruit cuticle thickening. The results of this study provide important genetic resources and a theoretical basis for molecular breeding of stress resistance and targeted improvement of fruit appearance quality in apple.

Horticulturae doi: 10.3390/horticulturae12040462

Authors: Muhammad Zeeshan Ali Pimjai Seehanam Darunee Naksavi Phonkrit Maniwara

Mold infection by Aspergillus and Penicillium spp. in Sithong sweet tamarind (Tamarindus indica L.) during commercial postharvest storage poses quality and food safety risks. However, the current visual detection method, which involves randomly cracking open the pods, is both destructive and laborious. The integration of near-infrared spectroscopy (NIRS) with artificial neural networks (ANN) enables rapid and non-destructive detection while capturing non-linear biochemical–spectral relationships, offering advantages over conventional destructive and linear analytical methods. It was tested as a mold classifier in sweet tamarind pods preserved in commercial ambient conditions (25 °C, 60% relative humidity) for five weeks. Six hundred pods were examined weekly using interactance spectroscopy (800–2500 nm) with six measurement points per pod and four spectral preprocessing methods. The ANN outperformed partial least squares discriminant analysis (PLS-DA) across all storage weeks, peaking at Week 2 with standard normal variate (SNV) preprocessing (prediction accuracy: 85.00%; sensitivity: 0.84; specificity: 0.86; F1-score: 0.85). Advanced tissue degeneration caused spectral heterogeneity, which decreased performance at Week 4 (prediction accuracy: 71.82–76.36%). Principal component loadings identified mold-induced water redistribution and carbohydrate depletion wavelengths at 938, 975–980, and 1035 nm. Week-adaptive calibration is essential for implementation because of the large difference between week-specific model accuracy (up to 85%) and overall storage model accuracy (63.53%). These findings provide a mechanistic underpinning for smaller wavelength-selective sensors and temporally adaptive mold screening systems in commercial tamarind storage.

Horticulturae doi: 10.3390/horticulturae12040461

Authors: Yan Bai Ceteng Fu Shen Liu Xichen Wang Jibo Fan Yuecheng Li Yihong Song

In the context of the rapid development of smart horticulture, a deep remote sensing-based dual detection method for horticultural crop growth anomalies and safety risks was proposed to address the limitations of existing remote sensing monitoring approaches. These conventional methods, which predominantly focused on growth vigor assessment or single-task anomaly detection, had difficulty distinguishing anomalies from actual production risks and exhibited insufficient sensitivity to weak anomalies and complex temporal disturbances. Within a unified framework, a growth state modeling branch and an anomaly perception branch were constructed, enabling the joint modeling of normal growth trajectories and anomalous deviation features. By further introducing a risk joint discrimination mechanism, an integrated analysis pipeline from anomaly identification to risk assessment was achieved. Multi-temporal remote sensing features were used as inputs, through which normal crop growth patterns were characterized via trend perception, texture modeling, and temporal aggregation, while sensitivity to local disturbances and weak anomaly signals was enhanced by anomaly embeddings and energy representations. Systematic experiments conducted on multi-regional and multi-crop horticultural remote sensing datasets demonstrated that the proposed method significantly outperformed comparative approaches, including traditional threshold-based methods, support vector machines, random forests, autoencoders, ConvLSTM, and temporal transformer models. In the dual task of horticultural crop growth anomaly detection and safety risk identification, an accuracy of approximately 0.91 and an F1 score of 0.88 were achieved, indicating higher anomaly recognition accuracy and more stable risk discrimination capability. Further anomaly-type awareness experiments showed that consistent performance was maintained across diverse real-world production scenarios, including climate stress, disease-induced anomalies, and management errors.

Horticulturae doi: 10.3390/horticulturae12040460

Authors: Mingzhu Wang Jing Xu Xueqing Zhao Zhaohe Yuan

The plant-specific TCP transcription factor family plays crucial roles in morphogenesis and stress adaptation. While characterized in many species, this family remains unstudied in Punica granatum. We performed the first genome-wide analysis of the TCP family in pomegranate, identifying 24 PgTCP genes classified into the PCF, CIN, and CYC/TB1 subclades, supported by conserved gene structures and motifs. Evolutionary analysis indicated segmental duplication and purifying selection shaped this family. Expression profiling revealed distinct spatiotemporal patterns: PgTCP2/9/14/21 were highly expressed in flowers, with PgTCP21 also notably abundant in fruit tissues (seed coats and pericarp), suggesting roles in reproductive development. PgTCP19, an ortholog of the branching suppressor BRC1, showed dominant expression in dormant buds, implicating it in shoot architecture regulation. Furthermore, PgTCP5 and the miR319-targeted PgTCP22 were leaf-predominant, indicating a function in leaf development. Under abiotic stress, PgTCPs displayed dynamic, treatment-specific responses. A subset of genes was rapidly induced by cold, while PgTCP14 and PgTCP23 showed sustained upregulation during drought. Several light-responsive PgTCPs were suppressed under shading. This study provides a foundational resource, functionally classifies the PgTCP family, and identifies key candidates regulating organ development and stress resilience for future functional validation and molecular breeding in pomegranate. This work provides the first comprehensive overview of the TCP gene family in pomegranate and offers candidate genes for future functional studies related to development and stress responses.

Horticulturae doi: 10.3390/horticulturae12040459

Authors: Qizong Lu Lina Yang Haoyan Yang Yujian Yuan Qinghua Lai Jisen Zhang

Citrus trees exhibit severe alternate bearing, resulting in significant annual yield fluctuations and posing substantial challenges to orchard management planning. Accurate citrus bud counting provides an effective solution by supplying essential data for tree-level and orchard-level yield prediction. However, citrus buds are extremely small (5–10 mm in diameter) and are frequently occluded by leaves during the flowering stage, which makes precise detection highly challenging in complex orchard environments. To address these challenges, this paper proposes a Contextual and Frequency-Aware Detector (CFADet) for robust citrus bud detection. Specifically, an Enhanced Feature Fusion (EFF) module is introduced in the neck to refine multi-scale feature aggregation and strengthen information flow for small targets. A Contextual Boundary Enhancement Module (CBEM) is designed to capture surrounding contextual cues and enhance boundary representation through dimensional interaction and max-pooling operations. To suppress background interference, a Frequency-Aware Module (FAM) is developed to adaptively recalibrate frequency components in the amplitude spectrum, thereby enhancing target features while reducing background noise. In addition, Spatial-to-Depth Convolution (SPDConv) is employed to reconstruct the backbone to preserve fine-grained bud features while reducing model parameters. Experimental results show that CFADet achieves 81.1% precision, 80.9% recall, 81.0% F1-score, and 87.8% mAP, with stable real-time performance on mobile devices in practical orchard scenarios. This study presents a preliminary investigation into robust citrus bud detection in real-world orchard environments and provides a promising technical foundation for intelligent orchard monitoring and early yield estimation, while further validation on larger and more diverse datasets is still required.

Horticulturae doi: 10.3390/horticulturae12040458

Authors: Xianjue Ruan Rongjin Ma Chunyu Shang Qingyuan Li Yu Pan Xin Hu

Tomato (Solanum lycopersicum) is a widely consumed vegetable crop and an established model system for plant functional genomics and genetic research in dicotyledons. Salt stress is a major abiotic factor limiting tomato productivity worldwide. The WRKY transcription factor family, one of the largest and most conserved plant-specific transcription factor families, plays pivotal roles in stress responses. This review summarizes recent advances in understanding the functions of tomato WRKY genes under salt stress, focusing on the genomic basis and evolutionary characteristics of the WRKY family, the roles of core WRKY members under salt stress, and the multi-layered regulatory networks mediating WRKY-dependent salt and alkali tolerance. To date, approximately 10 core SlWRKY genes have been functionally validated to regulate tomato salt tolerance, mainly by maintaining ion homeostasis, regulating reactive oxygen species (ROS) balance, facilitating osmotic adjustment, and integrating hormone signaling pathways. Despite this progress, systemic regulatory hierarchies and epigenetic modulation remain poorly resolved. Furthermore, we discuss how specific WRKY members directly regulate downstream effector genes, such as SlSOS1 and SlNHX4. However, direct experimental evidence for the coordination between tomato WRKYs and mitogen-activated protein kinase (MAPK) cascades, as well as epigenetic modifiers under salt stress, is still scarce in current studies. This review provides a theoretical framework and outlines potential technical pathways for translating fundamental insights into tomato salt tolerance into practical applications for sustainable agriculture.

Horticulturae doi: 10.3390/horticulturae12040457

Authors: Awais Ali Viviana Cavallaro Piero Santoro Jacopo Mori Giacomo Cocetta

The transition from High-Pressure Sodium (HPS) to energy-efficient Light-Emitting Diode (LED) supplemental lighting alters the plant thermal environment in controlled environment agriculture (CEA). This study evaluated how three practical supplemental lighting regimes, HPS, LED, and LED supplemented with infrared radiation (LED + IR), influence the physiology, growth, and phytochemical profile of Swiss chard (Beta vulgaris L.). We assessed biomass production, photosynthetic performance, oxidative stress markers (TBARS), and the concentration of primary and secondary metabolites. The LED treatment was superior for biomass production, yielding significant fresh mass while maintaining the lowest leaf nitrate content. Conversely, the addition of IR significantly increased leaf temperature, which suppressed growth but acted as a potent “bio-stress” agent, significantly increasing the total phenolic index. This biofortification, however, significantly decreased photosynthetic pigments (chlorophylls and carotenoids), increased lipid peroxidation (TBARS), and led to the highest accumulation of undesirable nitrates. Our findings reveal a clear growth-defense trade-off, demonstrating that while LED lighting is optimal for maximizing yield and food safety, the targeted application of IR radiation is an effective strategy for enhancing the nutraceutical value of leafy greens, requiring careful management to mitigate negative impacts on growth and quality.

Horticulturae doi: 10.3390/horticulturae12040456

Authors: Fabio Perotti Giuseppina Pennisi Matteo Landolfo Carlo Gravina Walter Menozzi Giorgio Gianquinto Francesco Orsini

Light quality plays a decisive role in controlled-environment agriculture, shaping plant morphology, physiology, and productivity. This study investigated the impact of far-red (FR) light on Cannabis sativa L. by comparing two different application strategies: continuous FR supplementation throughout 12 h of the photoperiod and end-of-day (EOD) FR exposure applied only at the end of the light period. In both treatments, FR was added to a background spectrum of red and blue (RB) light, while a control group grown under RB light alone was included to assess the specific effects of FR on plant growth, physiological responses, and flowering. Continuous FR exposure induced pronounced shade-avoidance traits, increasing plant height by 9% and petiole length by 17% relative to the control, and raised leaf dry weight to 12.9 g, 9% higher than under EOD (11.7 g) and 16.3% higher than under RB alone (10.8 g). Besides plant height and petiole length, both FR and EOD treatment induced limited morphological adjustments but increased chlorophyll content by 9%, resulting in greater canopy expansion and photosynthetic potential. However, flowering time was unaffected by spectral treatment, confirming that Cannabis floral induction is tightly regulated by photoperiod rather than light quality. Energy-use analysis revealed that EOD supplementation achieved many of the benefits of continuous FR while reducing overall consumption, but energy-use efficiency analysis proved FR as the more efficient treatment. These findings highlight the potential of FR light, particularly when applied continuously, to optimize vegetative growth and canopy physiology in controlled-environment Cannabis cultivation, while EOD strategies offer a practical compromise between cost savings and physiological benefits.

Horticulturae doi: 10.3390/horticulturae12040455

Authors: Tianci Hu Junping Yang Yu Lan Ying Huang Shanxin Zhong Xiangshu Dong

The SHAGGY-like kinase (SK) gene family regulates diverse developmental and abiotic stress response processes in plants. Although genome-wide analyses of SKs have been conducted in model plants such as Arabidopsis thaliana and rice, their characterization in the economically important crop Brassica rapa remains limited. In this study, we conducted a systematic genome-wide analysis of SK genes in three Brassica species. A total of 18, 16, and 18 SK members were identified in B. rapa, B. nigra, and B. oleracea, respectively, and phylogenetic analysis classified them into four distinct clades. Expression profiling revealed that BrSKβ-1 and BrSKβ-2 were specifically expressed in fertile floral buds, suggesting their critical roles in pollen development. Furthermore, co-expression analysis indicated that both genes were co-expressed with key regulators involved in pollen development, pollen sperm cell differentiation and pollen tube growth. Loss of BrSKβ-2 via CRISPR/Cas9 resulted in 25–65% pollen abnormality and reduced the germination rate of normal-appearing pollen to only 10%, confirming its essential role in male fertility. Together, these findings provide a comprehensive characterization of the SK gene family in Brassica and position BrSKβ-2 as a promising candidate for gene editing-based male sterility systems in B. rapa and related crops.

Horticulturae doi: 10.3390/horticulturae12040454

Authors: Hak Hyun Lee Yoo Kyong Han Jong Hoon Ahn Se Jeong Kim Qing Liu Bang Yeon Hwang Ki Yong Lee Mi Kyeong Lee

Actinidia arguta is a valuable plant resource known for its diverse bioactive constituents. However, organ-dependent metabolic variation remains insufficiently explored. In this study, an integrated approach combining LC–QTOF–MS-based metabolomic profiling, multivariate analysis, and phytochemical isolation was employed to investigate metabolic differences among fruits, leaves, and roots of A. arguta. Comparative LC–QTOF–MS profiling and principal component analysis (PCA) revealed clear organ-specific metabolic differentiation. The root extract formed a distinct cluster, primarily characterized by flavan-3-ol oligomers, including procyanidin dimers and a trimer. Targeted isolation and spectroscopic analysis identified these compounds as major constituents of the root. Quantitative analysis showed that the root exhibited the highest antioxidant activity (60.8 ± 6.2%) and total phenolic content (10.8 ± 0.7 mg GAE/g dried weight), followed by leaves and fruits, indicating significant organ-dependent variation. The enhanced antioxidant activity observed in the root extract was consistent with the enrichment of oligomeric procyanidins, which are known for their strong radical-scavenging capacity. These findings demonstrate pronounced organ-specific metabolic specialization in A. arguta, with the root characterized by a condensed tannin–dominant chemical profile. This study highlights the potential of root-derived procyanidins as bioactive natural products and provides a basis for their utilization in functional and phytochemical applications, as well as insights into plant defense-related metabolism.

Horticulturae doi: 10.3390/horticulturae12040453

Authors: Lucia Morrone Andrea Calderoni Giacomo Ferretti Giulio Galamini Annalisa Rotondi

Improving nitrogen (N) use efficiency in olive cultivation is essential to address the environmental burden of N fertilizers, whose recovery efficiency rarely exceeds 55%. This study evaluates the agronomic and environmental performance of chabazite-rich zeolite as a soil amendment to enable 50% N-fertilizer reduction in olive growing. A seven-year field experiment (2017–2023) was conducted at two sites in Emilia-Romagna (Italy)—one irrigated (Brisighella) and one rainfed (Bertinoro)—comparing four autochthonous varieties under zeolite amendment (ZEO, 50% N) versus conventional fertilization (CNT, 100% N). Vegetative growth, productive parameters, oil quality and environmental impacts (Life Cycle Assessment, ISO 14040/44) were monitored. Under irrigation, ZEO maintained vegetative and productive equivalence with CNT, sustaining commercially viable yields (0.5–2.3 t ha−1). Under rainfed conditions, variety-specific responses emerged: Colombina exhibited 126.2% greater trunk diameter and near-universal fruiting competence (88.9% vs. 29–35% productive plants) under ZEO, while Capolga showed treatment convergence. LCA revealed higher per-unit environmental impacts for ZEO during early orchard phases due to front-loaded extraction burdens, progressively offset by annual N-input reductions. These findings demonstrate that zeolite amendment enables agronomically viable 50% N-fertilizer reduction, with efficacy modulated by water regime and genotype.

Horticulturae doi: 10.3390/horticulturae12040452

Authors: Judit Bajzát József Rácz András Misz Csaba Balla Máté Vágvölgyi Sándor Kocsubé László Kredics Csaba Vágvölgyi Csaba Csutorás

Compost supplementation is widely used to improve yield and crop consistency in the cultivation of white button mushroom (Agaricus bisporus), yet practical alternatives to conventional protein-rich supplements and rapid candidate-screening approaches are still needed. In this study, plant- and byproduct-based supplements were first compared by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) to obtain qualitative fingerprints of extractable protein fractions, and were then evaluated in Phase III cultivation under both bag-based screening conditions and in a large-scale pull-mat system. Supplements differed notably in protein banding patterns and cultivation performance. In the bag trials, lupin grist and corn pellet produced the largest yield increases relative to the non-supplemented control, whereas in the commercial pull-mat trials lupin grist was the best-performing supplement, reaching 240.77 kg t−1 compost. Under the present conditions, SDS-PAGE was useful as a qualitative screening aid for prioritizing candidates for cultivation trials, but not as a stand-alone predictor of yield. These results identify lupin grist as a practically relevant supplement candidate for commercial A. bisporus production.

Horticulturae doi: 10.3390/horticulturae12040451

Authors: Eda Yaşa Özeltürkay Stefano Predieri Chiara Medoro Edoardo Gatti Marta Cianciabella Giulia Maria Daniele Luca Mazzoni Saila Karhu Terhi Latvala Ebru Kafkas Duygu Ayvaz Sönmez Klaus Olbricht Bruno Mezzetti

This study investigated consumer expectations and perceived quality of strawberries across different geographical contexts to identify the main drivers of purchasing behavior within a cross-country framework. An online survey was conducted among consumers in Italy, Germany, and Turkey to explore consumption habits, purchasing channels, sensory expectations, product perceptions, and willingness to pay (WTP) for specific product attributes. Results confirmed a high level of consumer appreciation for strawberries across all countries, primarily driven by their sensory characteristics. However, purchasing behavior and consumption patterns were strongly influenced by cultural and market-related factors. Visual attributes were confirmed to be key cues guiding product choice; however, label indications related to sensory traits and functional properties exerted a greater influence. Flavor, firmness, and overall taste balance represented critical determinants of consumer satisfaction. Differences across demographic groups were also observed, with younger and male consumers reporting lower levels of satisfaction with key sensory attributes, including juiciness, aroma, and freshness. Cross-country comparisons revealed heterogeneous WTP patterns, with Turkish consumers showing a greater propensity to pay premium prices for quality-related, local, organic, and environmentally friendly attributes compared with German and Italian consumers. Overall, the findings highlight the combined influence of sensory quality, cultural context, and sociodemographic characteristics in shaping strawberry perception and purchasing behavior. These insights may support breeders, producers, and retailers in developing targeted product strategies and market positioning across different geographical areas and consumer segments.

Horticulturae doi: 10.3390/horticulturae12040450

Authors: Xinran Zhang Junyu Zhang Xiaoqing Zhang Fangli Xia Qingyu Zhang

Fatty acids play critical roles in plant growth and stress adaptation, primarily through modulating membrane fluidity. This study combined bioinformatics (genome-wide identification and chromosomal localization) with experimental techniques (RT-qPCR, VIGS, and GC) to investigate the ARF family in Paeonia rockii. Seventeen PrARF genes were identified, showing evolutionary collinearity with Arabidopsis thaliana and Vitis vinifera and uneven chromosomal distribution. Among these, PrARF9 was specifically and highly expressed during late seed development, exhibiting a pattern highly consistent with the fatty acid synthesis key gene PrFAD3 and the accumulation trend of α-linolenic acid (ALA). In Nicotiana benthamiana, transient overexpression of PrARF9 upregulated its homologous gene NbFAD3, resulting in increased total fatty acid content and elevated lipid droplet accumulation. In contrast, in Paeonia rockii, silencing of PrARF9 downregulated PrFAD3 expression and reduced fatty acid levels, whereas overexpression of PrARF9 produced the opposite effect. We present a comprehensive analysis of the ARF gene family in P. rockii, combined with functional verification of a candidate gene regulating lipid synthesis. In summary, PrARF9 positively regulates PrFAD3, thereby participating in oil accumulation and ALA synthesis in P. rockii.