Horticulturae doi: 10.3390/horticulturae12091164

Authors: Mahdi Bikdeloo Hamid Reza Roosta Mohammad Javad Kalbali Nazim S. Gruda

The spectral composition and duration of light exposure can influence plant growth, secondary metabolism, and essential oil composition in medicinal and aromatic plants. Here, we evaluated the effects of lighting regime and exposure duration on the biochemical traits and essential oil composition of rosemary (Salvia rosmarinus Spenn.) under controlled conditions. Plants were exposed to white, blue, red, red/blue LED, or natural sunlight for 2, 3, or 4 weeks. The artificial light treatments were maintained at 200 ± 10 μmol m−2 s−1 PPFD, whereas the sunlight treatment was not PPFD-matched and therefore served as a greenhouse reference rather than a spectrum-matched control. Four biological replicates were used for each treatment. Chlorophyll, carotenoids, soluble sugars, total phenolics and flavonoids, DPPH radical scavenging activity, and essential oil composition were assessed. Essential oils were analyzed by gas chromatography–mass spectrometry (GC-MS). Lighting regime and exposure duration significantly affected several biochemical traits, whereas total phenolic content was not significantly affected by lighting regime. Red/blue LED treatment was associated with the highest mean values of total chlorophyll, carotenoids, total flavonoids, soluble sugars, and DPPH radical scavenging activity, although statistical significance varied among traits. Approximately 37 volatile compounds were identified across the treatments. The major constituents included α-pinene, 1,8-cineole, camphor, verbenone, borneol, bornyl acetate, and camphene and their relative abundances varied among lighting regimes and exposure durations. Principal component analysis (PCA) described differences in multivariate essential oil profiles among treatment combinations, while correlation analysis revealed associations among the relative abundances of volatile constituents. The highest essential oil yield was obtained under blue light at week 2 (1.53 ± 0.02% dry weight), whereas red/blue lighting at week 3 was associated with favorable responses in several biochemical traits. Thus, no single lighting regime and exposure duration was optimal for all measured traits. These findings indicate that lighting regime and exposure duration may be useful factors for modulating specific biochemical and essential oil characteristics of rosemary under controlled environment conditions.

Horticulturae doi: 10.3390/horticulturae12091163

Authors: Ying Tong Xiang Li Mingze Xu Sijun Qin Deguo Lyu Jiali He

To investigate the mitigating role and underlying mechanisms of exogenous boron (B) in cadmium (Cd)-stressed woody fruit trees, a hydroponic study was conducted using Malus hupehensis Rehd. seedlings treated with different B concentrations (0, 12.5, 50, and 150 μM H3BO3). Cd stress significantly inhibited plant growth and reduced photosynthetic parameters, pigment content, biomass, and root activity, but induced reactive oxygen species (ROS) accumulation. In contrast, the 50 μM B treatment (B2) effectively alleviated Cd toxicity. This treatment significantly decreased Cd accumulation, bioconcentration factor, and translocation factor across tissues. The B2 treatment enhanced Cd immobilization in root cell walls by increasing pectin content and pectin methylesterase activity. Additionally, it shifted Cd chemical forms toward lower-toxicity forms—increasing pectin- and protein-bound, phosphate-bound, and oxalate-bound Cd—while reducing inorganic and water-soluble Cd fractions. The B2 treatment elevated the activities of superoxide dismutase and peroxidase, and increased free proline and ascorbic acid, thereby reducing ROS and malondialdehyde accumulation. The B2 treatment also downregulated key genes including ZIP6 and IRT1 involved in Cd uptake. In conclusion, the most effective concentration among those tested (50 μM) alleviated Cd stress in Malus hupehensis Rehd., accompanied by modified Cd uptake and translocation, enhanced cell wall fixation, altered Cd chemical forms, improved antioxidant responses, and changes in stress-related gene expression.

Horticulturae doi: 10.3390/horticulturae12091160

Authors: Jianxiu Hao Xinmeng Jiang Zhiqiang Wei Chuandong Wu Xuezheng Wang Shi Liu Xufeng Fang Feishi Luan

Melon (Cucumis melo L.), a widely cultivated species of the Cucurbitaceae family, is one of the most economically important fruit crops globally. TRM proteins have been implicated in the regulation of plant development, including processes related to cell division, cell expansion, and organ morphology. Although the functions of TRM family members have been extensively characterized in Arabidopsis, tomato, and cucumber, their roles in melon fruit development remain poorly understood. In this study, a total of 22 CmTRM (Cucumis melo) genes containing the conserved DUF3741 and DUF4378 domains were identified from the melon genome data via bioinformatics approaches. Subsequently, we systematically analyzed the physicochemical properties of CmTRM-encoded proteins as well as the chromosomal distribution, gene organization, conserved motif patterns, and promoter regulatory elements of all 22 CmTRM members. Notably, the high-accuracy three-dimensional structure prediction of the CmTRM proteins were predicted using the AlphaFold3, intraspecific collinearity analyses of the CmTRMs were performed, seven pairs of collinear genes were identified. Additionally, phylogenetic analysis revealed that the CmTRM proteins could be classified into eight distinct clades, with CmTRM05 and CmTRM21 assigned to Group I. We performed quantitative real-time PCR (qRT-PCR) analysis on all 22 CmTRMs. The results showed that CmTRM05, CmTRM19 and CmTRM21 exhibited significantly distinct stage-specific expression patterns across fruit developmental gradients between the two melon accessions with contrasting fruit phenotypes. These three genes were therefore prioritized as candidate genes for subsequent genetic functional validation. Furthermore, subcellular localization assays revealed that CmTRM05 primarily resides in the cytoplasm. In conclusion, this study advances our understanding of the TRM gene family in melon and offers a theoretical and practical basis for investigating the influence of TRM on melon fruit shape, which is of great significance for developing new melon varieties with desirable fruit shapes.

Horticulturae doi: 10.3390/horticulturae12091161

Authors: Xinyuan Zhou Xinyi Tang Yingjie Suo Yueran Ma Rongrong Guo Jianjun He Xiongjun Cao Guo Cheng Miaomiao Cheng Longyan Zhang Haifeng Jia Sihong Zhou Jiayu Han Ying Zhang Ling Lin Yang Bai Shuyu Xie Yaqin Song Xiaoyun Huang Li Lu Xianjin Bai Bo Wang

Tropical viticulture has reached a considerable scale worldwide. Driven by innovative production systems such as two-harvests-a-year cultivation and ripening regulation, tropical grape-growing regions have become dynamic and economically significant viticultural areas. Most grape varieties currently cultivated in the tropics were originally bred in traditional temperate zones. When introduced to tropical regions, they often suffer from poor dormancy release, high disease and pest pressure, and compromised fruit quality. Therefore, it is imperative to conduct localized breeding directly under tropical stress conditions (e.g., high temperature, high humidity) to develop varieties with key target traits, including low chilling requirement, heat tolerance, disease resistance, suitability for two-harvest cultivation, good flavor, and good storage and transport tolerance. This paper systematically reviews the current status and breeding progress of the grape industry in major tropical viticultural regions, such as India, Brazil, and China. It summarizes the advances made by breeding teams in these countries in germplasm collection, crossbreeding, bud mutation selection, and the breeding and release of new varieties. The review concludes that developing adapted varieties through targeted breeding in tropics is essential for the sustainable and high-quality development of the grape industry in tropical regions.

Horticulturae doi: 10.3390/horticulturae12091162

Authors: Denisse Peña-Tapia Diana Curillo-Santos Santiago Guanuche Patricio Castro-Quezada Fabián León-Tamariz Jéssica Calle-López Oswaldo Jadán Paulina G. Villena-Ochoa Carlos A. Jiménez Álvaro Monteros-Altamirano Santiago Pereira-Lorenzo

Macleania rupestris is an underutilized wild fruit-bearing shrub native to the Ecuadorian Andes, with considerable ecological importance and potential for sustainable local development. However, information regarding its genetic, morphological, and phytochemical diversity remains scarce. This study aimed to characterize the genetic and morphological diversity and total phenolic content (TPC) of M. rupestris populations. A multilocus analysis was performed using three previously amplified concatenated sequences. Fruit characterization was conducted using quantitative morphological and physicochemical traits, while TPC was expressed as gallic acid equivalents and determined in fruits collected from the same individuals. Relationships among genetic, fruit, phytochemical, and environmental variables were also explored. The multilocus phylogenetic structure showed no clear geographic pattern, while most fruit traits exhibited limited differentiation among provinces. However, soluble solids content (°Brix), seed number, and pedicel length differed significantly among provinces. Fruit moisture content was moderately negatively correlated with soluble solids content (r = −0.45) and moderately positively correlated with seed number (r = 0.46). These correlations represent observational associations and do not demonstrate causal relationships. No significant correlation was detected between fruit traits and TPC. These findings provide important scientific basis for the conservation, selection of promising genotypes, and future domestication of this underutilized Andean fruit species.

Horticulturae doi: 10.3390/horticulturae12091159

Authors: Xing He Qi Guo Ziyi Li Xiaogai Hou

Ornamental plants encompass herbaceous to woody trees with rich interspecific diversity and morphological divergence; they are also horticultural crops of great ornamental, economic, and ecological importance. Floral morphotype constitutes a pivotal ornamental trait and a critical breeding indicator for novel cultivar improvement. Herein, we review floral morphotype formation from a multilevel regulatory perspective, focusing on the genetic and developmental networks, environmental signals, and biotic interactions that collectively shape floral diversity in ornamentals. We further summarize major technical approaches used in floral development research and highlight current knowledge gaps, particularly the limited understanding of interactions among regulatory layers. This review provides new insights into the mechanisms underlying floral diversification and offers a conceptual framework for targeted breeding of ornamental cultivars with novel floral morphology.

Horticulturae doi: 10.3390/horticulturae12091158

Authors: Kazuya Maeda Airi Okuyama Dong-Hyuk Ahn

In eggplant production, parthenocarpic cultivars are increasingly adopted to reduce labor associated with exogenous hormone applications for fruit set. Although optimizing training systems is essential to maximize the potential of these cultivars, associated quantitative evaluations of key physiological determinants, such as dry matter production and source–sink balance, remain limited. In this study, we investigated the effects of stem numbers on the yield and physiology of parthenocarpic eggplants grown in a soilless culture. Three treatments were established with varying stem numbers per plant (one, two, and four stems) and uniform stem density per area (3.75 stems m−2). The total yield and fruit number per unit area were highest in the one-stem treatment (1S) (8.5 kg m−2 and 60.0 fruits m−2, respectively), followed by the two-stem (2S) (7.1 kg m−2 and 50.9 fruits m−2) and four-stem (4S) (6.4 kg m−2 and 46.6 fruits m−2) treatments. Total dry matter production (TDM) varied similarly and was significantly higher in the 1S treatment than in the other systems. The 1S treatment exhibited rapid canopy development, reaching a higher leaf area index in the early stages, which contributed to greater cumulative light interception. Light use efficiency did not differ significantly among the treatments (5.2, 4.6, and 4.3 g MJ−1 for the 1S, 2S, and 4S treatments, respectively). Correlation analysis revealed a strong positive relationship between TDM and yield, whereas dry matter partitioning to fruit remained stable across treatments. These results indicated that the yield under these conditions was strongly driven by source capacity. We conclude that this single-stem training system represents an effective strategy for enhancing the canopy development and yield of parthenocarpic eggplants.

Horticulturae doi: 10.3390/horticulturae12091157

Authors: Janieli Maganha Silva Vivas Marcelo Vivas Derivaldo Pureza da Cruz Silvaldo Felipe da Silveira

Papaya black spot, caused by Asperisporium caricae, is commonly accompanied by fungi with potential mycoparasitic activity, but their temporal occurrence across host genotypes is poorly understood. We monitored black spot and fungal colonization monthly for 12 months in ‘Golden’, ‘Maradol’, and ‘Sekati’ papaya plants established in a randomized complete block design with 10 replicates. Papaya black spot incidence, the incidence of leaves containing mycoparasitized lesions, total and mycoparasitism-associated disease severity, the proportion of non-colonized lesions, and the occurrence of fungal morphotypes were evaluated on intermediate and last fully expanded leaves. Repeated observations were analyzed using linear mixed models with genotype, evaluation time, and their interaction as fixed effects and block and plant as random effects. Evaluation time and the genotype × evaluation-time interaction were significant for all response variables, indicating that genotype differences varied among months. Disease severity discriminated genotypes more clearly than incidence, with ‘Golden’ generally showing greater severity, particularly on the last fully expanded leaf. Structures morphologically consistent with Hansfordia pulvinata and Acremonium-like fungi predominated and showed distinct temporal patterns. These results demonstrate pronounced temporal variation in disease, lesion colonization status, and fungal occurrence, but do not establish biocontrol efficacy. Culture-based and molecular identification, followed by controlled antagonism assays, is required before management recommendations can be made.

Horticulturae doi: 10.3390/horticulturae12091156

Authors: Baojian Ma Yinghui Xia Bangbang Chen

Accurate picking-point localization and pose estimation are essential for selective robotic harvesting of marigolds, yet side-view imaging suffers from slender pedicel morphology, frequent occlusions, and weak visual contrast at the corolla–pedicel junction. This study aims to deliver a reliable perception framework that outputs both the 3D picking-point coordinates and the corresponding grasping pose angle for each harvestable flower. To achieve this, we propose an RGB-D based pipeline that integrates depth-assisted foreground extraction, a lightweight instance segmentation model, a dual-strategy corolla–pedicel association module, and geometric pose estimation. To improve pedicel segmentation under weak-boundary and occlusion conditions, an enhanced lightweight model, HSN-YOLOv8n-seg, was developed by incorporating Haar wavelet downsampling to preserve fine-grained texture features, Spatial Group-wise Enhancement to strengthen responses in ambiguous regions, and a lightweight segmentation head to improve mask boundary delineation. The model achieved a Precision of 78.53% and an mAP50 (mean Average Precision at IoU threshold 0.5) of 75.43%, with only 3.17 M parameters and an inference time of 9.42 ms, outperforming representative lightweight segmentation models such as YOLOv9t and YOLOv11n. The framework computes the pedicel centroid as the candidate picking point and pairs it with the corresponding corolla centroid via distance priority matching and cross-line verification; the axis connecting the paired centroids defines the picking pose. Outdoor experiments showed that the largest group-wise mean localization error was 0.0095 m (individual sample maximum: 0.0107 m), and the largest group-wise mean pose angle error was 5.11° (individual sample maximum: 14.14°). Overall, the framework consistently maintains reliable perception under occlusion and indistinct corolla–pedicel boundaries, demonstrating its potential for automated marigold harvesting. Nevertheless, further validation under diverse and complex field backgrounds is necessary before practical deployment.

Horticulturae doi: 10.3390/horticulturae12091155

Authors: Chun-Lan Piao Sui-Min Zhu Min-Long Cui

Highly efficient tissue culture and transformation systems are indispensable for micropropagation, the molecular studies of secondary metabolism, the biotechnological enhancement of bioactive compounds, and genome editing in plants. Solanum americanum is a diploid species with both vegetable and medicinal value, yet remains largely underutilized. It produces a various pharmacologically active secondary metabolites, including glycoalkaloids, tropane alkaloids, and resveratrol. However, stable genetic transformation and reliable genome editing protocols for this species remain underdeveloped. In this study, we established an efficient genetic transformation and genome editing method for S. americanum. Our results showed that nearly all leaf explants responded positively to MS medium supplemented with 2 mg L−1 6-benzylamino purine (6-BA) and 0.1 mg L−1 α-naphthaleneacetic acid (NAA), generating an average of 25.85 adventitious shoots per explants within four weeks. Furthermore, among kanamycin-resistant shoots, approximately 89.7% exhibited normal growth and over 75% showed strong GFP expression as well as inheritance, which was confirmed through molecular analysis and fluorescence assays in flowers, fruits, and T1 progeny. Moreover, we successfully utilized this transformation method to achieve stable genome editing of the phytoene desaturase gene (SaPDS). Our results demonstrate that the tissue culture, transformation, and genome editing methods established for S. americanum provide a valuable toolkit for large-scale propagation, the study of secondary metabolism, and the biotechnological improvement of this species.

Horticulturae doi: 10.3390/horticulturae12091154

Authors: Tamiris Dias Santana Iasmin Freitas Souza Thaise Dantas Fernanda Pacheco de Almeida Prado Bortolheiro Flávio Ferreira da Silva Binotti Eduardo Pradi Vendruscolo Eliana Duarte Cardoso Binotti Luís Humberto da Cunha Andrade Sandro Marcio Lima Edilson Costa

Sweet Basil (Ocimum basilicum L.) is a widely valued plant species with multiple applications, including use as a culinary herb and condiment, essential oil extraction, and traditional medicine. The present study aimed to evaluate the growth, photosynthetic pigments, and gas exchange of sweet basil plants under blue light supplementation and microalgae-based bioinput application. The experiment was conducted in a completely randomized design in a 4 × 2 factorial arrangement, comprising three blue light treatments (blue light was provided by LED lighting, dark blue glossy reflective laminate, and light blue glossy reflective laminate) plus a control, and bioinput application (presence and absence). The bioinput was prepared from Chlorella vulgaris microalgae biomass. Indirect blue light delivered by the dark blue reflective laminate, combined with C. vulgaris bioinput application, promoted the greatest increases in plant height, stem diameter, number of leaves, shoot dry matter, root dry matter, and total dry matter. Both direct blue light (LED) and indirect blue light (dark blue and light blue reflective laminates), in combination with microalgae bioinput application, significantly enhanced photosynthetic pigment contents—including chlorophyll a, total chlorophyll, and carotenoids—as well as transpiration, instantaneous carboxylation efficiency, stomatal conductance, and net photosynthetic assimilation rate. The multivariate analyses confirmed that blue light supplementation and C. vulgaris bioinput application act synergistically, promoting a distinct and superior physiological profile in sweet basil plants. These findings establish the combined use of blue light—direct or indirect—with Chlorella vulgaris microalgae bioinput as a promising and sustainable strategy for enhancing growth and photosynthetic performance of O. basilicum L. in protected cultivation systems.

Horticulturae doi: 10.3390/horticulturae12091153

Authors: Lorenza Vaccaro Roberta Spanò Fabio D’Alessandro Carmine Del Grosso Daniela Alioto Tiziana Mascia

Tomato (Solanum lycopersicum L.) is one of the most important solanaceous crops due to its economic and nutritional relevance. It hosts a wide range of plant pathogens, including a recombinant strain of potato virus Y (PVYC-to), which is considered one of the major threats in tomato cultivation. PVYC-to, a single-stranded RNA plant virus (family Potyviridae), mainly causes symptoms of mosaic, chlorosis, and vein necrosis in the leaves of horticultural crops, resulting in significant production losses. The ongoing evolution of viral strains, combined with the absence of natural resistance genes in commercial germplasm, requires the exploration of alternative management strategies, such as grafting, and the identification of resistant genetic resources within local biodiversity. This study aims to evaluate the response of five local tomato ecotypes (LTEs) from the Campania region—Corbarino, Giallo determinato da serbo, Pizzutello, San Marzano, and Vesuviano—to PVYC-to infection. The goal is to identify a naturally tolerant ecotype for use as a rootstock for commercial tomato varieties and expand the pool of resilient genetic resources against viral diseases. Visual symptom evaluation at 14 and 28 days post-inoculation (dpi), quantification of virus accumulation by qDot-blot, and thermal imaging analysis showed that all tested tomato ecotypes were susceptible to PVYC-to infection, although at different levels among the tested ecotypes. More specifically, Corbarino showed no significant changes in canopy temperature values, fewer symptoms, and reduced virus accumulation upon PVYC-to infection, compared to the other LTEs, and was therefore selected as a rootstock in subsequent experiments. The reduction in both symptom severity and viral RNA accumulation observed in grafted plants, combined with the mitigation of thermal stress in grafted scions, confirmed the efficacy of grafting as a viable management strategy and eco-friendly cornerstone for safeguarding regional agro-biodiversity against escalating viral pressures.

Horticulturae doi: 10.3390/horticulturae12091152

Authors: Grecia Hurtado Karla Pérez-Revelo

Soft fruits are highly perishable due to their delicate surface barriers, rapid cell-wall disassembly, turgor loss, oxidative imbalance, and tightly coordinated ripening and senescence processes that collectively accelerate water loss, softening, and decay after harvest. This review examines how melatonin (MLT) interacts with these deterioration processes in blueberries, raspberries, strawberries, grapes, and sweet cherries. Current evidence identifies redox regulation as the most consistent mechanism of MLT action, including modulation of reactive oxygen species, enhancement of antioxidant enzymes and the ascorbate–glutathione cycle, and maintenance of phenolic and other non-enzymatic antioxidants. These responses are linked with lower lipid peroxidation, reduced membrane leakage, delayed cell-wall degradation, and improved firmness, water retention, and decay resistance. More limited and species-specific evidence suggests that MLT may influence cuticular wax metabolism, endogenous MLT biosynthesis, H2S signaling, GABA and polyamine metabolism, phenylpropanoid pathways, and host-defense responses. However, direct evidence for effects on cuticular permeability, cellular compartmentation, and hormonal signaling remains limited. Overall, MLT should be regarded as a context-dependent regulator of redox homeostasis, tissue integrity, ripening, and defense rather than as a universal anti-senescence treatment, because its effects vary with species, cultivar, concentration, maturity stage, and storage conditions and still require validation under commercial conditions.

Horticulturae doi: 10.3390/horticulturae12091151

Authors: Yiqin Du Dongliang Zuo Beibei Gong Shilong Wang Mohan Li Ruxuan Guo Junkai Wu Xiao Xiao Libin Zhang Chenguang Zhang Xiaoshuang Zhang

Peach (Prunus persica) production and the northward expansion of its cultivation boundaries are severely constrained by recurrent extreme climatic events. Based on time-series transcriptomic analysis of two independent parallel treatments (cold stress and ABA application) and qRT-PCR validation, multiple candidate transcription factor genes co-responsive to both cold stress and ABA were identified (PpERF48, PpERF017, PpMYB6, PpWRKY46, PpWRKY40, and PpbHLH35). Among these, PpMYB6 was further characterized through bioinformatic analysis, and transgenic peach callus and Arabidopsis thaliana lines overexpressing PpMYB6 were generated, revealing its dual role in modulating plant growth and conferring low-temperature stress tolerance. Yeast one-hybrid and dual-luciferase reporter assays confirmed that PpMYB6 directly binds to and activates the PpCBF2 promoter. Yeast two-hybrid library screening identified DWARF8 as a candidate interacting protein, pointing to a working hypothesis by which PpMYB6 may negatively regulate vegetative growth via the gibberellin pathway. Together, this study characterizes a novel molecular module associated with cold tolerance and growth balance in peach, providing a promising candidate gene for molecular breeding of cold-resistant cultivars and rootstocks.

Horticulturae doi: 10.3390/horticulturae12091150

Authors: Paula A. Figueroa-Varela Carmenza E. Góngora Claudia P. Martínez Aristófeles Ortiz Lucio Navarro-Escalante Ricardo Acuña Diego Villanueva-Mejía

The coffee berry borer (CBB), Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), is one of the most destructive pests of coffee, causing significant losses in yield, bean quality, and overall crop profitability. Current integrated pest management strategies reduce damage but cannot prevent insects from locating and infesting coffee fruit. Because host selection by CBB relies on olfactory cues, modifying the emission of key volatile compounds represents a potential strategy to reduce pest attraction. This study aimed to decrease CBB attraction by editing genes involved in the biosynthesis of the monoterpenes limonene and pinene, which participate in host recognition. Agrobacterium-mediated transformation was performed in Coffea arabica seedlings, and gene editing used a binary vector carrying sgRNAs targeting terpene synthase genes, the cas9 gene, and the bar selection marker. Nine cas9-positive plants were obtained, including six of them also positive for bar, with seven plants exhibiting non-synonymous mutations at the target site for limonene synthase. Quantitative PCR (qPCR) analysis revealed a significant reduction in transcript levels in edited fruit, ranging from 95.5% to 99.2% compared to wild-type controls. Furthermore, GC-MS analysis confirmed a reduction of approximately 55% in limonene emission in variants exhibiting low-frequency mutations. Olfactometry bioassays revealed significantly reduced attraction, with only 17–36% of H. hampei females orienting toward edited fruit compared with 64–83% for wild-type controls (p < 0.05). These results suggest that targeted editing of limonene synthase can modulate volatile emissions and alter host-seeking behavior in H. hampei, providing a proof-of-concept for engineering crop plants with reduced pest attraction and offering a complementary, sustainable strategy for pest management in coffee production systems.

Horticulturae doi: 10.3390/horticulturae12091149

Authors: Felipe Marques de Lima Matheus Kainan de Paula Manjavachi Andressa Jociane Franzotti Menas Tiago José Leme de Lima de Nadai Simone da Costa Mello Fernando César Sala Fabia Barbosa da Silva Thais Queiroz Zorzeto-Cesar Luis Felipe Villani Purquerio

The optimal photosynthetic photon flux density (PPFD) and seeding density (SD) combinations for microgreens production on vertical farming systems remain unclear for many species. This study aimed to determine the effects of PPFD (50, 100, 150, and 200 µmol m−2 s−1) and SD for sunflower (1275, 1700, and 2125 g m−2), radish (272, 340, and 408 g m−2), and green and red cabbage (126, 180, and 235 g m−2) microgreens. PPFD had no effect on the yield of sunflower, radish, or red cabbage, indicating that 50 µmol m−2 s−1 was sufficient to meet plant demands. Green cabbage yield increased ~10% at 150 µmol m−2 s−1. Increasing SD enhanced yields, with gains of up to ~22%, 49%, 52%, and 30% for sunflower, radish, green, and red cabbage, respectively (1700, 408, 235, and 180 g m−2). PPFD did not affect the nutrient content of sunflower, likely due to its high seed reserves. A higher SD increased anthocyanin in red cabbage but diminished its content in all other species. Our findings highlight that SD is more impactful than PPFD on determining yield, at least under low irradiance, in sunflower, radish, and red cabbage microgreens grown on indoor vertical farming systems.

Horticulturae doi: 10.3390/horticulturae12091148

Authors: Changlin Li Qiaofeng Yang Xian Pei Yanfeng Xie Xuan Wu Chuanwu Yao Shukai Zhang Dejian Zhang Fuyuan Su Yan Wang

High-temperature stress can negatively influence citrus growth and fruit quality. Arbuscular mycorrhizal fungi (AMF) can enhance the absorption of water and nutrients, as well as improve heat resistance. In this experiment, we investigated the influence of heat stress (42 °C) on trifoliate orange (Poncirus trifoliata L. Raf.) with Funneliformis mosseae, (F.m, an symbiotic AMF associated with citrus). The results show that AMF markedly promoted seedling growth and enhanced photosynthesis. Compared with the 42 °C, 0 h conditions, the 42 °C, 6 h conditions markedly improved the REC and concentration of MDA, H2O2, soluble protein, soluble sugar, and Pro and significantly increased the enzyme activities of SOD (superoxide dismutase), CAT (catalase), and POD (Peroxidase), but they dramatically reduced the relative water content and photosynthetic parameters. Under high temperature (42 °C, 6 h), in contrast to the non-AMF groups, AMF treatment also observably improved the chlorophyll fluorescence and photosynthetic parameters, significantly decreased the REC by 26.52%, and markedly reduced MDA and H2O2 content by 25.61% and 35.66%. Moreover, AMF improved the concentrations of soluble protein, soluble sugar, and Pro markedly at 42 °C, 0 h (by 36.12%, 39.93%, and 20.81%), but these increased only by 13.31%, 3.11%, and 19.73% at 42 °C, 6 h. Furthermore, AMF increased the activities of SOD, CAT, and POD by 2.05%, 23.49%, and 2.02% at 42 °C, 0 h and by 4.74%, 20.85%, and 34.09% at 42 °C, 6 h compared with the non-AMF treatment. In addition, we found that the PtHSP7, PtHSP9, PtGOLS1, and PtHSFA1 genes all responded to high-temperature stress. Compared with the non-AMF treatment, after administering it at a high temperature (42 °C) for 6 h, AMF inoculation significantly up-regulated PtHSP7 but significantly down-regulated PtHSP9. In conclusion, AMF promotes the growth of trifoliate orange and enhances heat resistance via photosynthesis, osmoregulatory substances, the antioxidant system, and related genes.

Horticulturae doi: 10.3390/horticulturae12091147

Authors: Ivan Fedosiy Adolfs Rucins Dainis Viesturs Iryna Bobos Oleksandr Komar Oksana Tonkha Svitlana Kalenska Mykhailo Retman Maksym Babych

Lobo radish yield and quality depend heavily on summer sowing dates. A three-year field trial (2022–2024) in the Central Forest-Steppe of Ukraine evaluated four sowing dates–D1 (first decade of July), D2 (second decade of July), D3 (third decade of July), and D4 (first decade of August)–for cultivars Troiandova and Lebidka. Sowing in late July (D3) was optimal, securing maximum marketable yield (42.2 t·ha−1 for Troiandova, 38.9 t·ha−1 for Lebidka), peak marketability (70.5–72.0%), and minimal bolting (2.1–2.8%). Early sowing dates (D1–D2) increased bolting (up to 20.0%) and pest damage by cabbage root fly (Delia radicum L., 25.1–27.3%), reducing marketability to 45.4–52.0%. August sowing (D4) reduced root weight (204.6–224.3 g) but increased dry matter (8.6–9.8%) and soluble sugars (4.8–5.5%). AMMI and GGE biplots revealed higher yield stability for cultivar Lebidka (notably at D4), whereas Troiandova was highly responsive to optimal conditions (Troy-D3). Overall, sowing in the third decade of July (D3) is recommended for commercial production.

Horticulturae doi: 10.3390/horticulturae12091145

Authors: Yikai Wang Jiaying Sheng Chonghao Zhong Chaofan Zheng Jiaquan Huang Dongdong Li Fuwang Yang Zhifu Cui Guozhu Zhang Meng Wang Hua Tang

Durian (Durio zibethinus) germplasm may be incorrectly named, mislabeled, or genetically misidentified during introduction, exchange, and nursery stock distribution. Morphological identification is also affected by environmental conditions and plant developmental stages. A core simple sequence repeat (SSR) marker set was developed for the identification of durian germplasm. Genome-wide mining identified 106,776 SSR loci in the durian reference genome, and 18 stable and polymorphic markers were selected from 160 candidate primer pairs through agarose gel screening and M13-tailed fluorescent capillary electrophoresis. A total of 142 alleles were detected at the 18 SSR loci across the 58 durian accessions, with 3–15 alleles per locus and PIC values ranging from 0.422 to 0.849. Exhaustive evaluation of all marker combinations identified a minimum six-locus core SSR marker set comprising Y6, Y12, Y15, Y75, Y91, and Y108, which generated unique multilocus genotypes for all 58 accessions in the current validation panel, with a cumulative probability of identity (PID) of 7.99 × 10−8. STRUCTURE analysis, with K representing the number of inferred genetic clusters, supported K = 8 and revealed admixture in several accessions. The core SSR marker set developed in this study can distinguish the 58 durian accessions and be used to construct their DNA fingerprints. Validation in larger and more genetically diverse germplasm collections is required before routine commercial deployment.

Horticulturae doi: 10.3390/horticulturae12091146

Authors: Alexios Vasileios Tompros Eugenia Papadaki

‘Nagami’ kumquat (Fortunella margarita Swingle), a citrus fruit cultivated in Corfu, Greece, contains bioactive constituents whose levels may vary during fruit maturation. This study investigated changes in the physicochemical composition and bioactive potential of Corfu ‘Nagami’ kumquat during the commercial harvesting period (December–March) and optimized ultrasound-assisted extraction conditions for standardized comparisons among harvest stages. Fruits collected during the study period were analyzed for moisture, soluble sugars, proteins, lipids, total phenolic content, and free-radical scavenging capacity. Response surface methodology was used to optimize methanol concentration, extraction temperature, and extraction time, while principal component analysis (PCA) was applied to evaluate patterns associated with fruit maturation. During maturation, moisture and protein contents decreased, whereas lipid content increased. The optimized extraction conditions were 14% methanol, 45 min, and 54 °C. PCA showed clear separation of early- and late-harvest-stage samples, with the first two principal components explaining 97.9% of the total variability. The observed differentiation was primarily associated with DPPH scavenging, moisture, proteins, lipids, soluble sugars, and phenolic content. Late-harvest-stage fruits exhibited the highest free-radical scavenging capacity and phenolic content, with harvest stage related to variations in the bioactive potential of Corfu ‘Nagami’ kumquat.

Horticulturae doi: 10.3390/horticulturae12091144

Authors: Hyeong-Bin Park Jung Eun-Hwang Dae Young-Jeon Chang Woo-Lee Hwan-Joon Park Seongjun Kim Young-Joong Kim Young Jun Yoon

The authors would like to make the following corrections to the published paper [...]

Horticulturae doi: 10.3390/horticulturae12091143

Authors: Hongling Li Changchun He Yefang Li Wenling Guan

Rhododendron decorum Franch. has high ornamental value and emerging edible potential, but conventional propagation cannot meet the demand for high-quality, genetically uniform planting stock. This study optimized explant disinfection, adventitious bud induction, shoot proliferation, and rooting culture using stem segments and leaves from a winter-flowering naturally mutated individual of Rhododendron decorum, aiming to minimize contamination and browning. Results demonstrated that combined disinfection with 1% KMnO4 (10 min) and 10% H2O2 (4 min) outperformed single-treatment with 0.1% HgCl2. For primary culture, the optimal medium for adventitious bud induction was WPM + 30 g·L−1 sucrose + 7.5 g·L−1 agar + 0.56 g·L−1 Ca(NO3)2 + 100 mg·L−1 VC + 3 mg·L−1 TDZ + 0.1 mg·L−1 NAA, achieving an induction rate of 66.67%. During subculture, when the concentrations of TDZ and NAA were adjusted to 0.6 mg·L−1 and 0.05 mg·L−1, respectively, and 2 mg·L−1 GA3 was supplemented, stem nodes exhibited slight thickening but no significant shoot elongation. For rooting, the basal medium WPM + 20 g·L−1 sucrose + 7.5 g·L−1 agar + 0.56 g·L−1 Ca(NO3)2 + 100 mg·L−1 VC + 1 g·L−1 activated charcoal supplemented with 0.8 mg·L−1 NAA yielded superior rooting performance. Adding 2 mg·L−1 2iP tended to enhance rooting rate relative to the NAA-only treatment from an independent rooting experiment. For callus-mediated bud induction from leaves, 0.1 mg·L−1 TDZ + 0.01 mg·L−1 NAA was optimal. Notched fully expanded apical leaves from tissue-cultured plantlets showed highest adventitious bud induction under 0.3 mg·L−1 TDZ + 0.01 mg·L−1 NAA. The established micropropagation system supports bud sport variety selection, mass seedling production, and genetic transformation research.

Horticulturae doi: 10.3390/horticulturae12091142

Authors: Dinara S. Muraseva Olga A. Chernysheva Denis A. Krivenko Elizaveta N. Oborina Sergey N. Adamovich

The current challenges associated with the conservation and restoration of plant biodiversity make it necessary to test new biotechnological approaches. Optimizing the stages of clonal micropropagation using synthetic growth biostimulants—protatranes (1,2,3)—enables the targeted modification of physiological processes in plants. This increases their stress resistance, stimulates development, and reduces the cost of the final product. In this paper, the stimulating effect of the protatran (1), which we have named “crezacin”, on the processes of in vitro rooting and acclimatization to ex vitro conditions in microplants of the rare wild species Lilium pensylvanicum Ker Gawl was studied. No effect of crezacin and α-naphthylacetic acid on the development and growth of the microbulb during the rooting stage was detected. Crezacin at a concentration of 1.0 mg/L inhibited root elongation, but did not affect root number. Using α-naphthylacetic acid at a concentration of 0.93 mg/L was ineffective in inducing in vitro rhizogenesis. The survival rate of regenerated plants cultivated on media supplemented with crezacin was found to be 100%. The positive effect of crezacin on the content of photosynthetic pigments in the leaves of regenerated plants was also demonstrated. The addition of ultra-low concentrations (0.001–0.1 mg/L) of crezacin increased pigment content by up to 1.5 times (p < 0.05) compared to the control group. The increase in chlorophyll and carotenoid levels upon the addition of crezacin to the culture medium significantly facilitated the transition from a heterotrophic to an autotrophic mode of nutrition when microplants were transplanted into a soil substrate. Further research on clonal micropropagation of rare plant species and horticultural crops will be conducted using protatranes 2 and 3.

Horticulturae doi: 10.3390/horticulturae12091141

Authors: Chao Gao Peng Liu Shuai Li Jian Jiao Yumei Dong Chongqi Wang Jianlei Sun

To identify microRNAs (miRNAs) responsive to powdery mildew (PM) infection and elucidate their regulatory roles in melon PM resistance, thereby laying a foundation for deciphering the underlying molecular mechanisms, we combined high-throughput sequencing with bioinformatics analysis to screen PM-responsive miRNAs and their target genes using PM-resistant and PM-susceptible melon genotypes. In total, 113 non-redundant miRNAs were identified in both genotypes, including 70 known and 43 novel miRNAs. Subsequent differential expression analysis revealed distinct miRNA responses to PM infection between resistant and susceptible genotypes. Upon PM inoculation, 13 miRNAs showed significant differential expression in both susceptible and resistant genotypes. In addition, four miRNAs, including miR164c, miR396a, miR398a and miRn39, displayed differential expression specifically in the susceptible genotype. Conversely, five miRNAs (miR167c, miR398b, miR399g, miR530a and miRn8) showed differential expression exclusively in the resistant genotype upon PM infection. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses demonstrated that these miRNAs mediate melon’s susceptibility or resistance to PM by modulating plant immune homeostasis, antioxidant metabolism, and pathogen-triggered cell death. Quantitative real-time PCR (qRT-PCR) validation confirmed a negative regulatory relationship between the expression of PM-responsive miRNAs and their predicted target genes. Collectively, our findings provide novel insights and candidate targets for further investigations into miRNA functions and regulatory mechanisms underlying melon PM resistance.

Horticulturae doi: 10.3390/horticulturae12091140

Authors: Kare Mahmud Paul Cronje Dave Monks

Balancing the vegetative and reproductive developmental cycles in a citrus orchard is essential to maintain sustainability. Plant growth regulators (PGRs) offer an effective tool for managing shoot growth rate and fruit production of citrus trees. By moderating shoot elongation and reducing canopy expansion, PGRs help minimise the frequency and intensity of pruning, substantially reducing labour costs and improving orchard management. Evidence from multi-year experiments showed PGR-treated citrus trees can maintain or increase yield efficiency, producing equal or greater fruit/canopy (m3) than untreated controls. Strategic application of PGRs can moderate alternate bearing by promoting more consistent and fruitful shoots, stabilising annual yields. Economic assessments showed significant reductions in labour costs, especially when trees treated with PGRs required less hand pruning. This review synthesises historic and contemporary research and the mechanisms by which PGRs exert their effects in citrus. It identifies knowledge gaps, such as the need for long-term studies, optimal timing for different cultivars, and integrated strategies suited to different environmental conditions. Plant growth regulators could be an effective tool for stable citrus production, offering the potential for more efficient tree canopy management when used responsibly in accordance with regulatory requirements and integrated with other orchard management practices.

Horticulturae doi: 10.3390/horticulturae12091139

Authors: Cenap Yılmaz

This study compared four sweet cherry cultivars—Regina, Sweetheart, Kordia and 0900 Ziraat—at two sites of contrasting altitude in Eskişehir province, Türkiye: Eskişehir (792 m) and Sarıcakaya (220 m). Across two growing seasons (2016–2017; n = 64), phenological stages were recorded and fruit were assessed for eighteen pomological traits and three phytochemical measures—total phenolic content (TPC), total flavonoid content (TFC) and DPPH radical scavenging activity. Location affected almost every pomological trait measured: fruit from the cooler Eskişehir site were heavier and more intensely red, whereas fruit from the warmer Sarıcakaya site had higher soluble solids content and acidity, and reached bud break and bloom roughly 13 days earlier. TPC, TFC and DPPH activity were all higher at Eskişehir than at Sarıcakaya (TPC: 1071.0 vs. 823.3 mg GAE kg−1 FW; TFC: 344.3 vs. 234.6 mg CE kg−1 FW; DPPH: 45.5% vs. 22.5% inhibition; p < 0.001). Kordia stood out with the highest antioxidant activity and was also among the cultivars richest in phenolics and flavonoids. TPC and TFC were strongly correlated (r = 0.93), and both tracked with skin redness and lower titratable acidity. Overall, growing location, rather than cultivar, was the strongest factor behind the pomological, phenological and phytochemical differences observed over the two study years.

Horticulturae doi: 10.3390/horticulturae12091138

Authors: Jun Dong Jinbo Li Jinlong Li Zimo Zhang Nan Xu Haixiu Zhong Lijun Zhou

Salt stress restricts cucumber seedling establishment by impairing root development, photosynthesis, ion homeostasis, and redox balance. This study examined whether potassium silicate (K2SiO3) could partially alleviate these responses under hydroponic sodium chloride (NaCl) stress. Cucumber seedlings were exposed to six treatments: a nutrient-solution control, K2SiO3 alone supplying 1.0 mmol L−1 silicon (Si), 75 mmol L−1 NaCl, and NaCl combined with K2SiO3 supplying 0.5, 1.0, or 2.0 mmol L−1 Si. Growth, root morphology, photosynthetic pigments, gas exchange, chlorophyll fluorescence, photosystem II (PSII) energy partitioning, oxidative injury, antioxidant enzyme activities, osmotic adjustment, and ion status were evaluated at 7 and 14 d. NaCl markedly reduced seedling growth, root development, net photosynthetic rate, PSII photochemical performance, and electron transport, while increasing leaf sodium (Na+), malondialdehyde accumulation, non-photochemical quenching, non-regulated energy loss, proline, and soluble sugar. K2SiO3 partially alleviated these changes. The treatment supplying 1.0 mmol L−1 Si produced the strongest integrated recovery of growth, root activity, photosynthetic performance, PSII function, and oxidative status. The treatment supplying 2.0 mmol L−1 Si resulted in the lowest leaf Na+ concentration and the highest leaf potassium (K+)/Na+ ratio among salt-stressed seedlings but did not produce the greatest growth recovery. These findings suggest coordinated changes in photosynthesis, photochemical energy use, redox status, and ion balance. Because K2SiO3 supplied both Si and K+, the results represent responses to K2SiO3 supplementation rather than Si-specific effects.

Horticulturae doi: 10.3390/horticulturae12091137

Authors: Xinting Ding Yumian Cui Hao Li Zhanhua Song

Honeysuckle (Lonicera japonica Thunb.) is a medicinal and edible plant whose flower buds are widely used in functional foods, herbal beverages, and natural antioxidant products. Accurate identification of harvestable buds is important because flower developmental stage affects the accumulation of bioactive constituents and the commercial value of raw materials. In this study, an improved YOLOv8n-based detection model, termed MHF-YOLO, was developed to identify immature, harvestable, and over-mature honeysuckle buds under field conditions. A custom dataset containing 400 original images was constructed and annotated into three categories. Large Separable Kernel Attention (LSKA) was introduced into the backbone to enhance feature representation under complex backgrounds, and the original CIoU loss was replaced with WIoU for bounding-box regression. Ablation experiments showed that the combined modifications improved mAP50 from 76.4% to 85.6% and mAP50:95 from 46.5% to 50.8%, while increasing the parameter count by only 3.4%. Compared with representative detection models, MHF-YOLO achieved a precision of 84.3%, a recall of 74.8%, an mAP50 of 85.6%, and an inference time of 7.09 ms. Compared with the recent lightweight YOLO11n baseline, MHF-YOLO achieved a slightly lower overall mAP50 (85.6% vs. 86.1%) and lower inference efficiency, but obtained a higher precision (84.3% vs. 83.7%) and a slightly higher mAP50:95 (50.8% vs. 50.1%) under the present experimental setting. Category-wise evaluation showed that MHF-YOLO achieved the best class-wise performance for harvestable buds, with a precision of 88.2%, a recall of 76.1%, an mAP50 of 93.7%, and an mAP50:95 of 63.2%. A PyQt5-based recognition system was further developed to support single-image, batch, and camera-based continuous recognition. These results indicate that the proposed MHF-YOLO-based platform is a feasible visual-recognition and decision-support prototype for commercial-grade honeysuckle assessment under the present field conditions.

Horticulturae doi: 10.3390/horticulturae12091136

Authors: Sheraz Ahmad Rahat Sharif Xiaotong Feng Peng Zeng Kang Li Jiping Liu Ling Tian

Glyphodes pyloalis Walker is a devastating phytophagous pest of mulberry (Morus spp.) that severely compromises leaf yield and quality, thereby threatening sericultural productivity. Although jasmonic acid (JA) and salicylic acid (SA) are well-established regulators of plant antiherbivore defenses, their specific roles in modulating mulberry responses to G. pyloalis herbivory remain poorly understood. Here, we employed an integrative approach combining herbivory bioassays, exogenous hormone treatment, physiological analysis, and RNA-sequencing (RNA-seq) to dissect JA- and SA-mediated defense networks in mulberry. Exogenous application of both hormones enhanced chlorophyll content, with JA exerting the strongest effect. However, they differentially modulated antioxidant enzyme activities, with SA primarily elevating superoxide dismutase (SOD) and JA enhancing peroxidase (POD) and catalase (CAT). Transcriptomic and functional-enrichment analyses showed that JA-responsive DEGs were predominantly associated with photoprotection, carbohydrate metabolism, phenylpropanoid and flavonoid biosynthesis, MAPK signaling, ABC transporters, and defense-related enzyme functions. By comparison, SA-responsive DEGs were strongly associated with photosynthesis-related gene expression, chloroplast organization, carbon metabolism, glutathione metabolism, and systemic immune-related processes. Notably, several key transcription factors, including MaHDZIP1, MaLBD28, MaGATA5, MaTALE2, MaARF4, MaSBP1 and MaSBP12, were upregulated under both hormone treatments. Collectively, these findings indicate that exogenous JA and SA treatments elicited overlapping yet distinct defense-related responses in mulberry. This work provides an integrated physiological and transcriptomic framework for the future development of hormone-mediated strategies against G. pyloalis in sericulture.

Horticulturae doi: 10.3390/horticulturae12091135

Authors: Jiayang Chen Peixun Chen Jianjun Tan Yiwei Zhou Lishan Huang Tangchun Zheng Yuanjun Ye

Globba spp. is a perennial herbaceous plant of the Zingiberaceae family, characterized by its unique floral architecture and diverse coloration with high ornamental and medicinal value. However, research on the genetic basis of Globba is still insufficient, and only a limited number of molecular markers have been developed so far, which has greatly hampered the progress of its molecular breeding. Herein, we performed the first deep identification of genome-wide SSR markers based on the whole-genome data of G. sherwoodiana. A total of 276,809 SSR loci were identified with an average density of 189.24–297.49 SSRs/Mb within each chromosome. Mononucleotide repeat loci were most abundant, accounting for 58.95% of all SSRs, with dinucleotide and trinucleotide repeats accounting for 19.83% and 19.27%, respectively. Using G. sherwoodiana ‘MJ16’ and G. winitii C.H. Wright as parental lines, we constructed a hybrid F1 population containing 173 individual plants. The coefficient of variation (CV) of the 10 phenotypic traits ranged from 13.09% to 27.43%, exhibiting a normal distribution. Phenotypic traits including terminal leaf width, inflorescence length, inflorescence width, secondary-inflorescence pedicel length, number of ornamental bracts, and basal inflorescence-bract length showed abundant variation, with all CV values exceeding 20%. Moreover, 27 polymorphic genomic SSRs (gSSR) were screened from the synthesized 192 primer pairs, amplifying a total of 203 alleles. On average, each marker detected 7.52 polymorphic loci, with a mean effective allele number of 3.63 and a mean polymorphism information content of 0.64, reflecting a relatively rich genetic diversity within the population. Through phenotype–marker association analysis, six gSSR loci were found to be significantly associated with six phenotypic traits. The highest interpretation ratio (16.86%) was observed for basal inflorescence-bract width. Three loci (gSSR48, gSSR105 and gSSR184) were simultaneously associated with more than two phenotypic traits, indicating a pattern consistent with pleiotropy or linkage. The informative gSSR markers and the association analysis results in this study provide an effective theoretical basis for germplasm identification, genetic diversity evaluation, and marker-assisted breeding of Globba.

Horticulturae doi: 10.3390/horticulturae12091134

Authors: El Hadi Erbiai Fidel Carlos Jaime Fernanda Leal Guilhermina Marques

Potato (Solanum tuberosum L.), the third most important food crop worldwide, is constrained by phytopathogens, environmental stress, and heavy agrochemical use. Potato micropropagation is a biotechnological strategy for producing genetically uniform, pathogen-free plantlets. However, the acclimatization phase remains a major bottleneck in micropropagation, often resulting in poor survival and stunted growth. In this context, plant growth-promoting bacteria (PGPB) represent a sustainable strategy to improve plantlet establishment and reduce reliance on synthetic inputs. This study evaluated the biofertilization and biocontrol potential of three Douro vineyard-associated bacterial strains, Bacillus velezensis Nb1, Burkholderia pyrrocinia Gs3, and Streptomyces sp. 42s5, identified using 16S rRNA and gyrB sequence analysis. In dual-culture assays, the isolates showed antagonistic activity against Fusarium oxysporum, F. solani, Botrytis cinerea, and Alternaria alternata. All strains also exhibited key plant growth-promoting traits, including indole-3-acetic acid and siderophore production, and phosphate solubilization. The isolates were tested individually and in consortia on micropropagated potato plantlets during acclimatization under greenhouse conditions. Eight treatments (six replicates each), including a non-inoculated control, were evaluated. The results indicated that inoculations significantly improved vegetative growth and yield-related parameters. Notably, the Gs3 + 42s5 combination produced the highest shoot biomass, while the three-strain consortium achieved the greatest total tuber weight (36.91 g/plant) compared to the control (7.75 g/plant). These findings highlight the potential of these native PGPB, particularly when applied in multi-strain combinations, to enhance acclimatization efficiency and support sustainable potato production by reducing dependence on chemical inputs and promoting eco-friendly agricultural practices.

Horticulturae doi: 10.3390/horticulturae12091133

Authors: Onakho Manciya Beverly M. Mampholo Semkaleng Mpai Dharini Sivakumar

Despite the increasing adoption of soilless cultivation systems, little is known about how the gravel flow technique (GFT) influences postharvest quality, phytonutritional composition, and shelf life of cauliflower compared with conventional soil cultivation, and how these effects interact with cultivar genotype. Therefore, this study evaluated the influence of production system (soil cultivation vs. GFT), cultivar, and storage duration on the postharvest physiology, quality, and phytonutritional attributes of three cauliflower cultivars (‘Macerata’, ‘Sicilian Violet’, and ‘Snowball’) stored at 4 °C for 8 days. Significant production system × cultivar × storage interactions affected physiological, biochemical, and sensory characteristics. Soil-grown curds maintained higher O2 and lower CO2 concentrations, indicating lower respiration rates and slower deterioration than GFT-grown curds. ‘Snowball’ exhibited the highest weight loss and respiratory activity, whereas ‘Sicilian Violet’ showed the lowest weight loss. Soil cultivation enhanced the retention of phenolics, glucosinolates, pigments, and antioxidant activity. After 8 days, soil-grown ‘Sicilian Violet’ exhibited the highest total phenolic content (55.25 mg GAE g−1 DW) and antioxidant capacity, while the highest glucosinolate concentration was recorded in soil-grown ‘Macerata’ (48.23 µmol g−1 DW on day 6). ‘Macerata’ maintained the highest chlorophyll and β-carotene contents throughout storage, whereas ‘Sicilian Violet’ showed superior anthocyanin retention and antioxidant capacity. Although sensory quality declined during storage, soil-grown curds retained better quality and lower browning than GFT-grown curds. Overall, soil cultivation improved postharvest quality and nutraceutical value, highlighting the importance of integrating cultivar selection with production practices to optimise shelf life and nutritional quality.

Horticulturae doi: 10.3390/horticulturae12091132

Authors: Suliya Ma Yuanyuan Zhao Xiao Zhang Wenxuan Dong Yuexue Liu

Hawthorn (Crataegus spp.), a horticultural crop with significant edible, medicinal, and ornamental values, has garnered increasing attention from breeders to markets, leading to continuous emergence of new varieties. Accurate phenotypic characterization and robust Distinctness, Uniformity, and Stability (DUS) testing are fundamental for plant variety protection and breeding innovation. Employing the Chinese DUS Test Guidelines for Hawthorn (LY/T 3208-2020) as an analytical framework, this study systematically evaluated 197 germplasm accessions from the Chinese National Field Genebank. Results demonstrated: (1) Coefficients of Coincidence (COC) for example varieties and test traits ranged between 0.980 and 1.000, fully meeting the testing requirements; (2) the 22 qualitative (QL) and pseudo-qualitative traits (PQ) were categorized into 2–5 classes with Shannon-Wiener indices of 0.032–1.174, indicating high polymorphism; (3) correlation analysis of 11 quantitative traits (QN) revealed coefficients from 0.006 to 0.922, with 23 trait pairs showing statistical significance, while principal component analysis identified fruit and leaf traits as primary drivers of phenotypic variation; (4) grading schemes were established by using Least Significant Difference (LSD) for eight normally or near-normally distributed traits (5–7 classes) and range-based grading approach for three non-normal traits (5 classes). Based on the above results, this study evaluated China’s current DUS testing guidelines for hawthorn. Subsequently, 197 hawthorn accessions were used to evaluate the QL, PQ, and QN traits, based on which corresponding optimization recommendations were proposed. Ultimately, an optimized testing framework for hawthorn DUS testing was established. The resulting analytical insights and phenotypic grading system will enrich the current descriptor framework and provide a foundational dataset for trait-DNA association and marker-assisted breeding. Notably, this optimization strategy serves as a methodological template for updating DUS guidelines in other taxa. Overall, these insights strengthen the protection, development, and breeding of new hawthorn varieties while advancing the standardization of DUS testing.

Horticulturae doi: 10.3390/horticulturae12091131

Authors: Ezio Portis Anna Maria Milani Elsa Martini Giuseppe Caputo Matteo Martina Cinzia Comino

Italian sweet pepper landraces represent an important reservoir of genetic diversity, although their practical exploitation in breeding programmes remains limited. Historical germplasm collections preserve variation accumulated through centuries of farmer selection, but their organization into resources suitable for pre-breeding and parental selection has rarely been investigated. In this study, 35 historical Piedmont sweet pepper accessions conserved in the DISAFA Genebank and five historical breeding reference lines were characterized through quantitative fruit phenotyping and genome-wide SNP genotyping. A total of 190 individuals were genotyped by ddRADseq, yielding a final dataset of 1925 filtered SNP markers. Phenotypic characterization confirmed the major historical fruit morphotypes, while genome-wide analyses revealed genetic relationships broadly consistent with traditional morphotype classification and the history of conservative selection. Comparison between historical accessions and the corresponding sampled reference lines identified complementary private variation in all comparable genomic groups, although private variation was also detected in the reference materials. On this basis, we propose Historical Breeding Pools as a breeding-oriented interpretive framework integrating genomic relationships, traditional morphotypes and historical breeding reference lines to organize conserved diversity for future pre-breeding and parental selection. These results show how historical genebank collections can be characterized beyond conservation alone and used to prioritize genetic resources for further breeding-oriented evaluation.

Horticulturae doi: 10.3390/horticulturae12091130

Authors: Yakun Zhang Xiangkai Liu Yimeng Wang Jinying Zhang Yalin Zhang Ronglin He Jie Gao Zhongwei Zou Lifeng Duan Yun Jiang Changqing Chen

Ginseng (Panax ginseng), a traditional and valuable medicinal plant, is severely affected by rusty root rot caused by Ilyonectria robusta. Xylanase is hypothesized to play a key role in the pathogenicity of I. robusta. Through transcriptomic analysis during ginseng infection, the highly expressed xylanase gene IrXyn01 was identified. A PEG-mediated genetic transformation system for I. robusta was established in this study, with optimized protoplast preparation yielding 1.4 × 107 protoplasts/mL and 36% transformation efficiency. IrXyn01 was successfully knocked out by using the CRISPR/Cas9 method. No significant differences in colony morphology, growth rate, sporulation, and spore germination were observed between mutants and the wild-type stain, indicating IrXyn01 is unrelated to vegetative growth. Under salt stress (KCl and NaCl), mutant inhibition reached 37.2% and 48.2% compared with the wild-type, respectively. The gene also regulated nitrogen source utilization, particularly for ammonium sulfate (29.3% inhibition of the knockout). When xylan was the sole carbon source, ΔIrXyn01 showed 12.8% growth inhibition. Neutral xylanase activity in mutants remained low (35–46 nmol/min/mL), compared to 138–142 nmol/min/mL in the wild-type strain and complemented strains. Pathogenicity assays confirmed that the IrXyn01 knockout significantly reduced disease severity, with lower rusty root rot severity in ginseng inoculated with mutants. This study identified IrXyn01 as a virulence gene in I. robusta and improves our understanding of its molecular pathogenesis.

Horticulturae doi: 10.3390/horticulturae12091129

Authors: Dongdong Yang Weikang Kong Zihao Chen Wenge Liu Nan He Xiaowen Luo Jiayin Zhang Danmei Zhu Xuqiang Lu Hongju Zhu

Free amino acids serve as a crucial hub connecting plant life activities with human nutrition. The fruits of Cucurbitaceae crops are natural nitrogen reservoirs, rich in free amino acids such as citrulline, arginine, and γ-aminobutyric acid (GABA). To investigate the spatial accumulation characteristics and differential distribution of free amino acids in cucurbit fruits, this study measured the contents of 19 free amino acids in the fruit stem, epicarp, endocarp, pulp, and seeds of 10 cucurbit species (12 varieties) at the mature stage. The results revealed that free amino acid accumulation exhibits significant tissue specificity and species specificity, forming diverse nitrogen metabolism hubs. Glutamine, aspartate, asparagine, arginine, and citrulline constitute a highly coordinated core module of nitrogen metabolism in Cucurbitaceae. Methionine, valine, and some other amino acids were consistently present at extremely low levels across tissues, indicating a competitive diversion of conserved metabolic pathways coexisting among species. Species classification based on free amino acids differed markedly from traditional taxonomy based on gene domestication, implying environmental selection pressures and non-linear gene-metabolite network relationships. Glutamine, GABA, citrulline, and arginine were identified as core hub metabolites supporting tissue type classification. This study revealed the allocation characteristics of free amino acids in fruits of various cucurbit crops and established a functional model integrating nitrogen assimilation, flavor/energy metabolism, stress tolerance/defense signaling, and storage across different tissue types of multiple cucurbit crops, providing new perspectives for precision breeding and domestication mechanism research in Cucurbitaceae.

Horticulturae doi: 10.3390/horticulturae12091128

Authors: Jinling Feng Xinyu Wen Piao Yang Qingshan Chen Yu Huang Yanjin Lin Zhijian Yang

Hovenia acerba is a high-value multipurpose tree with edible, medicinal, and timber applications. However, systematic investigations of phenotypic variation, phenotypic diversity, and phenotype–environment associations for H. acerba germplasm in Fujian Province remain limited, which impedes targeted breeding and efficient resource exploitation. In this study, 25 quantitative morphological traits were assessed across 31 H. acerba accessions originating from 11 Fujian provenances. Multiple analytical pipelines were implemented, including analysis of variance, temporal repeatability estimation, correlation analysis, principal component analysis (PCA), cluster analysis, and climate–trait correlation analysis. Abundant phenotypic variation and considerable phenotypic diversity were detected. Infructescence-related traits exhibited the largest variation (mean coefficient of variation = 0.42), while fruit-associated traits had the highest mean repeatability (temporal repeatability = 0.52), demonstrating strong multi-year phenotypic temporal consistency. Observed phenotypic correlations suggest a putative trade-off between vegetative and reproductive growth. Primary peduncle length was strongly associated with yield performance, and tree height emerged as a promising candidate trait for potential early-stage seedling-based selection. PCA condensed the 25 traits into five principal components that collectively explained 73.94% of the total phenotypic variation. Six candidate evaluation indices were identified within this germplasm panel, and accessions were grouped into five phenotype-based clusters that were not congruent with their geographic provenances. Exploratory correlation analyses revealed that annual precipitation was positively associated with yield-related traits, while elevated spring high temperature (March to April) was negatively associated with infructescence-related phenotypes. Eight phenotypically superior candidate accessions were preliminarily selected for edible peduncle or dual-purpose cultivation for both fruit and timber outputs. This study fills regional research gaps and provides a reliable phenotypic dataset and preliminary candidate germplasm to support the conservation, characterization, and directional breeding of H. acerba germplasm.

Horticulturae doi: 10.3390/horticulturae12091127

Authors: Hengmin Lv Yue Wu Mengting Xiao Jian Luo Xilin Hou Xiong You

Light is a key environmental factor regulating plant photosynthesis, yet the coordinated effects of photoperiod and light intensity on photosynthetic dynamics in non-heading Chinese cabbage remain unclear. Using experimental data, we developed a circadian clock-controlled photosynthesis model integrating photoperiod and light-intensity inputs. The model was calibrated and evaluated against experimental observations and was then used to analyze circadian gene expression, diurnal net photosynthetic rate (Pn), light-period net CO2 assimilation, and the marginal carbon benefit of increasing daily light integral (DLI). Under a constant DLI of 9.216 mol·m−2·d−1, extending the photoperiod from 8 to 20 h while reducing light intensity from 320 to 128 µmol·m−2·s−1 lowered and delayed the instantaneous Pn peak but progressively increased light-period net CO2 assimilation. Among the treatments examined, 20L:4D produced the highest net CO2 assimilation. Moreover, across the simulated DLI range of 5–19 mol·m−2·d−1, the 20-h photoperiod consistently produced the highest net assimilation, whereas the marginal carbon benefit of additional light declined by approximately 62%. The results suggest that distributing a fixed daily light input over a longer photoperiod at lower instantaneous light intensity can enhance daily carbon gain within the tested range, whereas increasing DLI produces progressively diminishing photosynthetic returns. This study provides a modeling framework for evaluating photoperiod–light intensity coordination and provides a quantitative basis for optimizing light–environment management in controlled-environment agriculture.

Horticulturae doi: 10.3390/horticulturae12091125

Authors: Zhu Lian Mengze Li Xiaoyu Wang Meng Li Lan Li Xuxu Niu Xiang Li Juan Hou Qiong Li Wenwen Mao Lili Li Chen Luo Jianbin Hu Panqiao Wang

SHN (SHINE) transcription factors belong to the AP2/ERF superfamily. They regulate cuticular wax biosynthesis and abiotic stress responses in plants, and play crucial roles in fruit netting development of cucurbit crops. However, a systematic genome-wide analysis of the SHN gene family in melon has not yet been reported. In this study, the thick-skinned melon cultivar ‘L5283’ was used as experimental material, and nine CmSHN family members were identified at the whole-genome level. We systematically analyzed their physicochemical properties, chromosomal distribution, evolutionary conservation, promoter cis-acting elements, and expression patterns under four types of stresses. The results showed that the nine CmSHN genes were unevenly distributed across six chromosomes. Extensive synteny was observed among SHN genes of cucurbit species including melon, watermelon and cucumber, with higher genomic structural conservation detected between cucumber and melon. Six categories of cis-elements were enriched in CmSHN gene promoters, namely light-responsive, hormone-responsive, stress-related, and development-associated elements, along with circadian rhythm and flavonoid biosynthesis elements. Light-responsive elements were the most abundant, suggesting that light signals may contribute to the regulation of CmSHN transcription. RT-qPCR analysis under ABA, cold, drought and salt stresses revealed that all CmSHN genes were induced to varying degrees, with obvious differences in response patterns and duration. Notably, CmSHN7 exhibited markedly higher fold induction than other family members under all four stress treatments. This study systematically characterizes the fundamental features and stress response patterns of the CmSHN family in melon, provides baseline data for elucidating the molecular mechanisms underlying wax biosynthesis and fruit netting formation, and supplies candidate genes for molecular breeding of stress resistance in cucurbit crops.

Horticulturae doi: 10.3390/horticulturae12091126

Authors: Tiantian Yang Liyuan Yang Jiejun Xu Xiya Sun Yi Tang Chaonan Wang

Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step in lignin monomer biosynthesis and is crucial for plant cell-wall lignification. However, the CAD gene family and its role in watermelon rind lignification are poorly understood. In this study, we performed genome-wide bioinformatics analysis to identify the CAD gene family in watermelon. We identified predicted gene expression in two contrasting cultivars [WRH (hard rind, high lignin) and WRS (soft rind, low lignin)]. A total of seven CAD-like genes (ClCAD1–ClCAD7) were identified on three chromosomes (1, 2, and 5), all encoding full- or near-full-length proteins with CAD-related domains. Genomic collinearity revealed one segmental duplication (ClCAD3–ClCAD4) in watermelon; however, the comparative genomes of Arabidopsis and melon identified five and eight homologous gene pairs, respectively. Phylogenetic analysis indicated that ClCAD-like genes are more closely related to melon than to Arabidopsis. ClCAD3 and ClCAD4 proteins were grouped with AtCAD4 and AtCAD5 from Arabidopsis, which are important for lignin biosynthesis. Promoter analysis predicted elements responsive to jasmonic acid, abscisic acid, cytokinin, light, and stress. Subcellular localization analysis in the epidermal cells of Nicotiana benthamiana leaves was consistent with a cytosolic distribution for ClCAD3. STRING analysis predicted functional associations of ClCAD3 with proteins involved in aldehyde metabolism, branched-chain amino acid biosynthesis, and basal carbon metabolism, including ClALDH1/2, ClALS, Cl2HACL, and ClKBA1. qRT-PCR analysis of roots, stems, leaves, and fruit rind (21 days after pollination, DAP), as well as rind at 1, 14, and 28 DAP, indicated that ClCAD3, ClALS, and ClALDH2 are expressed at higher levels in WRH than in WRS. ClCAD3 transcript abundance in roots, leaves, and fruit rind was consistently higher in WRH. Together, these findings clarify the evolutionary features and organ-level expression of the CAD-like gene family in watermelon and identify ClCAD3 as a candidate gene associated with lignin biosynthesis. The results provide genetic insights into candidate genes potentially involved in lignification-associated rind hardness and a theoretical foundation for improving rind texture in watermelon fruit through modern molecular breeding approaches.

Horticulturae doi: 10.3390/horticulturae12091124

Authors: Xiaodong Zhang Shifang Song Chuandong Guo Xiangyu Han Zonghua Leng Yixue Zhang

Protected horticultural crops are commonly produced at high planting densities and have short production cycles; imbalances in water and fertilizer supply can rapidly affect plant vigor, yield, and quality. Non-destructive diagnostic methods are therefore needed to characterize plant nutritional status under greenhouse conditions. Spectral imaging can simultaneously capture spatial and spectral information associated with pigments, water status, tissue structure, and canopy phenotype. It does not directly detect nutrient ions; rather, it captures physiological and structural responses that may be associated with nutrient status and may also be influenced by water deficit, disease, temperature, salinity, phenology, and genotype. This review focuses on crops grown in soil, substrate, and hydroponic systems under greenhouse conditions. Studies conducted in vertical farms, growth chambers, and open fields are included only as supplementary references for sensor selection, model calibration, and inspection methods. This article synthesizes diagnostic indicators for nitrogen, phosphorus, and potassium, together with their associated physiological responses and spectral characteristics; compares the performance of hyperspectral, multispectral, and machine learning methods at the leaf, plant, and canopy scales; and examines fixed measurement, stop-and-go mobile inspection, continuous motion imaging, and autonomous plant revisitation. Existing studies have established a solid foundation for nutrient content retrieval, deficiency identification, and mobile monitoring. However, several challenges remain inadequately addressed under continuous inspection conditions, including radiometric–geometric joint calibration, plant identity preservation, acquisition of multi-element chemical truth values, model generalization across growth stages and greenhouse types, and long-term performance evaluation. Future work should refine standardized protocols for dynamic data collection and water–fertilizer environmental control, integrate mechanistic constraints with data driven approaches, and incorporate plant re-identification, spatiotemporal registration, uncertainty quantification, and online calibration. These efforts will contribute to constructing a long-term stable and comparable nutritional diagnostic system, thereby advancing the transition of facility vegetable nutritional monitoring from single-time static measurements toward continuous, traceable, and autonomously patrolled systems that may ultimately support precision irrigation and fertilization management after appropriate independent validation.

Horticulturae doi: 10.3390/horticulturae12091123

Authors: Scott A. Heckathorn Emina Kostic Jennifer K. Boldt

Nutrient-uptake proteins (NUPs) have the potential to serve as biomarkers for crop improvement, with most studies to date focusing on NUP gene sequence or mRNA levels. In this paper, we examined if protein levels of the main iron (Fe)-uptake proteins in roots scaled with sensitivity to Fe deficiency among five tomato (Solanum lycopersicum) cultivars grown at low or medium Fe (0.5 or 50 μM). Across cultivars, biomass, shoot Fe concentration, and leaf chlorophyll concentration ([chl]) were lower at low vs. medium Fe, but the concentrations of the main Fe-uptake proteins in roots [iron-regulated transporter (IRT), plasma-membrane H+-ATPase (H+-ATPase), and ferric reduction oxidase (FRO)] were generally higher at low vs. medium Fe (both per unit total root protein and per g). Among cultivars, the % change between controls and low Fe in [chl], a common biomarker for Fe deficiency, and fresh biomass were positively correlated (r = 0.78, p = 0.12). In contrast, the % decrease in plant mass at low (compared to medium) Fe was inversely correlated with the % increase per unit total protein in levels of IRT (r = −0.93, p = 0.02) and, to a lesser extent, FRO (r = −0.82, p = 0.09), but was not correlated with % change in levels of H+-ATPase (p = 0.34). However, sensitive cultivars exhibited decreases in root protein concentration per g root at low vs. medium Fe, while tolerant cultivars had higher root protein levels at low Fe, which resulted in similar levels of IRT per g root among cultivars. Thus, among tomato cultivars, while low Fe generally induced increases in the main Fe-uptake proteins in roots, these increases were not higher in cultivars tolerant of low Fe; instead, tolerance to low Fe among cultivars was related to the ability to increase the concentration of total protein in roots.

Horticulturae doi: 10.3390/horticulturae12091122

Authors: Qunhao Zheng Liuyang Yue Liyang Su Saike Jiang Yinyin Tan Xiongkui He

Fruit-tree pruning has to keep tree structure under control while continually renewing fruiting wood, and many decisions still depend on practical experience. This narrative review synthesizes 92 English-language publications from 1983 to 2026, identified through Google Scholar and backward citation tracking. As orchard systems become more regular and mechanization expands, mechanical pruning has been used to control canopy edges. Vision and 3D sensing are now being used to identify branches and locate pruning points, while robotic systems are beginning to attempt selective pruning. This review looks at the literature at canopy and branch scales. Mechanical canopy pruning is effective for quickly treating regular canopy profiles, but field trials show that regrowth, follow-up manual pruning, and crop-load management can change later yield and economic outcomes. Branch-level automation has moved from 2D recognition to 3D reconstruction, pruning-point generation, and small-scale robotic trials. The harder questions are increasingly about branch function and continuous whole-tree operation. For pruning automation, machine speed or a successful cut is only part of the result; post-pruning tree responses and longer-term production also have to be considered. Multi-temporal tree records, branch-function information, continuous operation, and long-term field testing deserve more attention.

Horticulturae doi: 10.3390/horticulturae12091121

Authors: Zhiyi Zhang Yufang Hu Qi Liang Siqing Fan Ling Zhang Tingting Jing Ying Xiong Lang Yang Mingkun Huang Hua Yang

Chromatin accessibility is an important feature of cis-regulatory elements that shapes gene regulation in plants; however, it has been studied less frequently in traditional medicinal plants such as Gardenia jasminoides J.Ellis (G. jasminoides). This study applied Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) technology to characterize the genome-wide distribution and functional features of accessible chromatin regions (ACRs) in G. jasminoides leaves. A total of 26,461 ACRs and 13,625 associated genes were identified in this study, and our results revealed a positive correlation between the open chromatin state of ACRs and the expression levels of their associated genes. These ACRs were also found to be enriched with numerous conserved transcription factor binding motifs (TF motifs). Integration of two histone modification datasets further demonstrated that ACRs are closely associated with activating histone modifications, including H3K4me3 and H3K27ac, which work together to regulate the transcription of target genes. Additionally, luciferase (LUC) reporter assays validated the transcriptional activation activity of two candidate ACRs. Taken together, these findings elucidate the genomic features of ACRs in G. jasminoides and provide critical genomic resources for subsequent gene regulation analyses for this species.

Horticulturae doi: 10.3390/horticulturae12091120

Authors: Daniela Nicuță Luminița Grosu Roxana-Elena Voicu Irina-Claudia Alexa

Plant tissue and cell culture techniques have proven to be a suitable tool for increasing fresh biomass and stimulating the plant secondary metabolite biosynthesis, offering important advantages compared to conventional plant propagation. Medicinal and aromatic plants represent species of interest due to their rich content in bioactive compounds, with various applications in different fields, including the food industry. The micropropagation technique, through the production of a large number of in vitro plants, can ensure, in a short time and with high efficiency, the adequate amount of fresh biomass to cover the need for the extraction of significant active principles for their use in the food industry as natural preservatives and antioxidants, as well as coloring and flavoring agents. This narrative review aims to provide a comprehensive analysis of the strategic micropropagation methods applied to medicinal and aromatic plants, including sustainable approaches (e.g., organic nutrient supplementation of the culture medium), as well as their advantages and limitations. Moreover, this bibliographical study highlights the role of the in vitro multiplication technique in enhancing the accumulation of secondary metabolites such as phenolics, flavonoids, alkaloids, terpenoids, saponins, etc., supporting their use for a more sustainable future in food systems. Finally, the present analysis points towards emerging future directions for exploiting the micropropagation technique on a large scale as a valuable and promising tool to reach its full potential as a source of novel biomolecules. This comprehensive integration serves as a valuable reference for researchers and industry experts in both plant biotechnology and food science and technology.

Horticulturae doi: 10.3390/horticulturae12091119

Authors: Fenghou Shi Xing Chen Yuhui Zhang Yue Ni Yingang Li Yue Zeng Yongbao Shen

Grafting is the primary vegetative propagation technique for ornamental crabapple, and rootstock–scion compatibility critically determines graft healing efficiency and seedling quality. Selecting suitable rootstocks is essential for the popularization of new crabapple cultivars, yet the healing performance of the newly bred cultivar Malus ‘Huabiao’ grafted onto different local Malus rootstocks remains unclear. This study evaluated graft compatibility for M. ‘Huabiao’ grafted onto three rootstocks (M. hupehensis, M. robusta, and M. baccata) through histological observation and dynamic detection of soluble sugar, soluble protein, and tannin during graft healing. The results indicated that M. ‘Huabiao’/M. hupehensis and M. ‘Huabiao’/M. robusta achieved higher survival rates (80.0% and 83.3%, respectively) and complete vascular reconstruction within 28 days, whereas the M. ‘Huabiao’/M. baccata combination exhibited a lower survival rate (63.0%) and obvious healing lag. All combinations showed consistent physiological variation trends, while the M. baccata group maintained higher soluble sugar content, greater protein fluctuations, and significantly elevated tannin levels (p < 0.05). Physiological substance accumulation was closely correlated with healing performance, with higher soluble sugar and protein levels associated with better wound recovery, and excessive tannin accumulation correlated with retarded tissue regeneration capacity. Distinct healing asynchrony was observed among combinations, with incomplete vascular connection detected in the M. baccata group at day 28. This study confirms that M. hupehensis and M. robusta are superior compatible rootstocks for M. ‘Huabiao’, and the dynamic levels of the three physiological indices can serve as potential indicators for evaluating crabapple graft compatibility.

Horticulturae doi: 10.3390/horticulturae12091117

Authors: Wenshu Sun Yujie Gao Weiyi Zhou Diya A Tao Zhou Zhaoyue Zheng Bohai Wu Wenbo Tan Zedong Wu Yongli Hao

Sugar beet (Beta vulgaris L.) is a major sugar-producing crop worldwide, yet rhizomania, root-knot nematode, and root rot diseases severely constrain its yield and quality. Screening resistant germplasm is critical for disease-resistant breeding and sustainable sugar beet production. In this study, we evaluated the disease resistance of 96 introduced sugar beet cultivars via molecular marker assays and field disease nursery trials. The results showed that 76 cultivars (79.2%) carried the strong resistance genotype for rhizomania, and 20 cultivars (20.8%) carried the weak resistance genotype. For root-knot nematode, 87 cultivars (90.6%) were heterozygous resistant, while 9 cultivars (9.4%) were homozygous susceptible; no homozygous resistant genotype was detected in this study. Field evaluation of root rot showed that disease incidence ranged from 15.45% to 100%. Only one cultivar (KWS7772) was rated as resistant (R), accounting for 1.0%, and two cultivars were moderately resistant (MR), accounting for 2.1%. Among all tested cultivars, KWS7748 showed combined resistance to rhizomania, root-knot nematode, and root rot. These findings provide candidate resistant germplasm resources and baseline resistance data under the tested conditions for sugar beet disease resistance breeding; further multi-environment and multi-year validation is needed, particularly for root rot resistance, before these varieties can be recommended for commercial deployment.

Horticulturae doi: 10.3390/horticulturae12091118

Authors: Georgeta Mihaela Bucur Elena Delian Roxana Mihaela Filimon George Adrian Cojocaru

Climate change strongly impacts the physiological processes in the grapevine. Two Romanian autochthonous cultivars, Șarba and Fetească neagră (Vitis vinifera L.), grown under semi-arid conditions in 2024 (De Martonne Index: 23.6; Hydrothermal Coefficient: 0.75), showed different physiological behaviours. Leaf gas exchange parameters (A, gs, E, Ci) and water use efficiency (WUE) were assessed at three phenophases (flowering, berry growth, and véraison), while photosynthetic pigment indices (Chl a/b, Chl/C+X) and leaf dry matter content (dm) were additionally determined at harvest maturity. Multivariate analysis consistently separated the two cultivars into distinct physiological groups: responses consistent with near-isohydric behaviour in Șarba and anisohydric behaviour in Fetească neagră, based on gas-exchange parameters interpreted within the established isohydric/anisohydric framework, as direct water potential measurements were not performed. Șarba exhibited a water-conserving strategy at véraison—characterised by early stomatal closure, high WUE, and maintained chlorophyll—protecting vine water status at the cost of reduced leaf carbon assimilation. Fetească neagră, by contrast, kept its stomata progressively open, sustaining high gas exchange rates in a pattern consistent with progressively declining shoot water potential. Berry sugars are expected to concentrate passively late in ripening, while severe deficit risks berry shrivelling and, under prolonged drought, premature senescence of basal leaves, to our knowledge, a phenomenon not previously reported for this cultivar. These findings support cultivar-specific management, with implications for irrigation scheduling and varietal selection under climate change.

Horticulturae doi: 10.3390/horticulturae12091116

Authors: Tingting Xu Zengwei Yang Jiajia Zhao Yingying Hu Yuqing Cheng Xuehao Chen Xiaohua Qi Qingmin Xie

Waterlogging stress is a major abiotic stressor that severely constrains crop growth and productivity. Aerenchyma provides intercellular air spaces to transport oxygen to the root, which is essential for survival under waterlogged conditions. However, the mechanism underlying the response to waterlogging and aerenchyma formation in luffa remains poorly understood. In this study, we identified distinct phenotypic responses between two cultivars: ‘Zhonglü’ exhibited aerenchyma formation in the hypocotyl under waterlogging, whereas ‘Yalü’ did not. Transcriptome profiling of ‘Zhonglü’ revealed differentially expressed genes linked to plant hormone signal transduction, including fifteen auxin-related and two jasmonate-related genes, which may be involved in waterlogging-induced aerenchyma formation and are proposed as candidate regulators. Furthermore, exogenous application of 5 μmol/L N-1-naphthylphthalamic acid (NPA) and 20 μmol/L methyl jasmonate (MeJA) significantly enhanced aerenchyma formation. Notably, these treatments uncovered a regulatory node wherein NPA-disrupted auxin transport and jasmonate signaling converge to coordinately fine-tune the expression of ARF18, IAA32, GH3.17 and TIFY9 genes in the hypocotyl. Taken together, this study definitely advances our knowledge of the morphological and transcriptomic responses of Luffa under waterlogging stress and sheds new lights on its adaptive mechanisms.

Horticulturae doi: 10.3390/horticulturae12091115

Authors: Hernando Araujo-Vasquez Amparo Rosero Carina Cordero Adriana Tofiño Rommel León Martha Montes Alfonso Orozco Nilson Osorio Jorge García Laura Restrepo Hernán Ceballos Jhon Larry Moreno Christian Salazar Luis Londoño

Cassava is a crop of major socioeconomic and cultural importance in Colombia. One of the main challenges is production seasonality, driven by climatic conditions that constrain planting and harvesting periods. Currently, cultivated varieties exhibit a substantial reduction in root dry matter content (DMC) following the onset of the rains. This study evaluated the agronomic performance of genotype SM2828-28 under semi-commercial field conditions in the departments of Cesar, Bolívar, and Magdalena in the Colombian Caribbean region. This genotype exhibited greater stability and productivity, outperforming commercial checks. The genotype also showed high and stable DMC. Root quality and starch functional properties were also assessed. Starch from SM2828-28 exhibited numerically lower setback values and a relatively consistent rheological profile across harvest ages, indicating greater gel stability during cooling—an attribute desirable for industrial applications requiring consistent textural properties. The genetic progress achieved for key industrial traits highlights the potential of SM2828-28 for extended-harvest systems aimed at reducing seasonality in raw material supply for the cassava starch industry. These results suggest that genetic factors contribute to the stability of DMC under extended-harvest conditions and support the inclusion of this trait as a target in cassava breeding programs.

Horticulturae doi: 10.3390/horticulturae12091114

Authors: Xinmin Lv Qian Li Junbin Wei Jing Wang Dongmei Han Jianguang Li Shilian Huang Dongliang Guo

The HB (homeobox) transcription factor family plays important roles in plant growth, development, morphogenesis, and stress responses; however, its involvement in longan (Dimocarpus longan Lour.) fruit energy metabolism remains unclear. In this study, 32 DlHB family members were identified in the longan genome, and their physicochemical properties, phylogenetic relationships, gene structures, conserved motifs, conserved domains, tissue-specific expression patterns, promoter cis-acting elements, and collinearity relationships were systematically analyzed. The DlHB family was classified into four subfamilies, HD-ZIP I–IV, with substantial divergence in structural composition, expression patterns, and putative regulatory features. Our previous work showed that 1.5% chitosan (CTS) treatment improved postharvest longan fruit quality through modulation of energy metabolism, and the corresponding CTS-treatment transcriptome was therefore used here to screen energy-metabolism-associated DlHB candidates. DlHB22 was selected as a representative candidate, and its CTS-responsive expression was independently confirmed by qRT-PCR. Exogenous ATP treatment was then used as an independent physiological validation of the relationship between energy metabolism and postharvest storability; ATP-treated fruit showed reduced deterioration together with higher ATP, ADP, and AMP contents and higher activities of H+-ATPase, Ca2+-ATPase, cytochrome c oxidase (CCO), and succinate dehydrogenase (SDH) at 15 d, although adenylate energy charge (AEC) was lower than in the control. DlHB22 localized predominantly to the nucleus. Heterologous overexpression of DlHB22 in tomato accelerated fruit color transition and ripening progression and altered ATP, ADP, and AMP contents, AEC, and the activities of H+-ATPase, Ca2+-ATPase, CCO, and SDH. Transcriptome analysis of DlHB22-overexpressing tomato fruit revealed broad transcriptional changes in pathways associated with central carbon metabolism, energy metabolism, glutathione metabolism, hormone signaling, and MAPK signaling, and qRT-PCR validation of six representative DEGs was consistent with the RNA-seq trends. Because tomato is climacteric whereas longan is non-climacteric, the heterologous tomato results demonstrate the regulatory potential of DlHB22 but do not establish an identical native ripening pathway in longan. Overall, DlHB22 is best regarded as a candidate transcription factor associated with longan fruit energy metabolism, whose native regulatory mechanism requires direct validation in longan.

Horticulturae doi: 10.3390/horticulturae12091113

Authors: Kimberly Heagy Kyle Austin Freedman Mark Hoffmann

The containerized production of grapevines has increased recently in the United States. Using container systems is a paramount consideration for nursery profitability and plant growth. Nurseries aim for a system that optimize greenhouse space and shipping costs, while maintaining transplant quality. Limited research has been conducted on the effects of container systems on grapevine growth and physiology traits. The goal of this study was to evaluate the effects of commercially used container systems in US nurseries on plant biomass, root morphology, and leaf function during nursery production. One-year old own-rooted ‘Concord’ and ‘Traminette’ grapevines were grown for 104 days in three commercial nursery container systems: ‘small’ (7.6 × 20 cm, 1.2 L tapered, internal vertical walls), ‘medium’ (10 × 23 cm, 1.5 L, tapered, internal vertical walls), and ‘large’ (15 × 40 cm, 4.4 L, rectangular, smooth-walled). Neither shoot nor root dry weights were affected by the container system in any of the cultivars; similarly, the root morphology of none of the cultivars was affected by the container system. The container system did not impact leaf function (photosynthetic rate, transpiration rate, stomatal conductance) observed; however, small container systems led to lower chlorophyll content in both cultivars. Our study suggests that all tested container systems are applicable for grapevine nurseries.

Horticulturae doi: 10.3390/horticulturae12091112

Authors: Jieqi Zhang Yadong Li Chenyu Wang Feng Miao Lijuan Qie Changbao Li Ming Zhou Ainong Shi Qingzhen Yin Shanshan Wang

Soil salinization is a major abiotic constraint on tomato production worldwide. To evaluate adult-stage tomato performance under contrasting saline and non-saline conditions, 23 tomato accessions (13 large-fruited and 10 cherry types) were evaluated at two solar-greenhouse locations in Hebei Province, China: a non-saline site in Shijiazhuang and a saline–alkali site in Huanghua, Cangzhou. Eleven growth, biomass, yield, and quality traits were assessed, and salt tolerance coefficients (STCs) were calculated to characterize relative trait performance between the two sites. Accessions were also genotyped using a PARMS marker linked to SlHAK20. Biomass accumulation was generally lower at the saline site, with above-ground and root dry weights showing the largest relative differences between the two sites, whereas plant height differed comparatively little. Total soluble solids (TSS) were higher at the saline site in most accessions, with the largest relative difference (91.7%) observed in large-fruited accession 305. Correlation analysis revealed strong positive associations between fresh and dry weights of both shoot and root tissues (p < 0.0001). Large-fruited accession 305 and cherry accession 436 showed comparatively favorable biomass retention and relatively small morphological differences between the two sites and therefore represent candidate accessions for further evaluation. The observed SlHAK20-linked marker genotypes were not consistently aligned with phenotypic performance among accessions, indicating that the predictive value of this marker requires further validation. These findings should be interpreted cautiously because salinity was confounded with location, the experiment was conducted during a single growing season, and the marker analysis was not validated in an independent population. This study provides a preliminary comparative evaluation approach and candidate accessions for further investigation and breeding of tomatoes adapted to saline environments.

Horticulturae doi: 10.3390/horticulturae12091111

Authors: Fengyun Xiang Tianya Liu Mengdie Li Mingjuan Wan Zheng Zhang Jifu Li

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Horticulturae doi: 10.3390/horticulturae12091110

Authors: Gilson Gustavo Lucinda Machado Adriana Guerreiro Custódia Gago Mariana Guita Maria Dulce Carlos Antunes Elisângela Elena Nunes Carvalho Eduardo Valério de Barros Vilas Boas

Bioactive polysaccharide-based edible coatings are promising strategies for maintaining postharvest fruit quality. This study aimed to extract and characterize crude polysaccharides from Brazilian Hovenia dulcis (HDPs-BR) and evaluate their potential as edible coatings, alone or combined with sodium alginate (SA) and eugenol (Eug), for strawberry preservation. HDPs-BR showed an extraction yield of 5.31 ± 0.19%, with 62.68 ± 1.90% total sugars, 24.95 ± 0.39% uronic acids, and 5.33 ± 0.23% proteins. They also contained phenolic compounds and exhibited antioxidant activity. Coating performance depended on formulation and storage period. After 15 days, HDPs-BR 0.5% provided the highest firmness, whereas HDPs-BR 1% favored phenolic and anthocyanin retention and red color. SA-containing formulations showed attribute-dependent benefits: HDPs-BR 0.5% + SA 0.5% promoted high phenolic content, while its combination with Eug 0.1% improved luminosity and antioxidant activity at specific storage periods. HDPs-BR 1% + Eug 0.1% maintained a red color and showed high anthocyanin content and antioxidant activity. Overall, HDPs-BR demonstrated potential as a bioactive edible coating matrix, with formulations containing SA and Eug providing additional benefits depending on the quality attribute evaluated.

Horticulturae doi: 10.3390/horticulturae12091109

Authors: Valerio-Landa Sergio David Evangelina Esmeralda Quiñones-Aguilar Angela Michelle González-López Luis Guillermo Hernández-Montiel Gabriel Rincón-Enríquez

In plants, pathogen-associated molecular patterns (PAMPs) activate pattern-triggered immunity and can contribute to resistance against phytopathogenic infections. Identifying novel microbial elicitors is important for developing resistance-inducing strategies that reduce reliance on pesticides. This study evaluated BV801-derived protein preparations obtained from Xanthomonas euvesicatoria strain BV801 grown in host-associated media containing lyophilized Solanum lycopersicum or Capsicum annuum tissue. Six treatments were evaluated in C. annuum against bacterial spot caused by X. euvesicatoria (BSX) under in vitro conditions: SP-AWSL and SP-AWCA (obtained from BV801 grown in the host-associated AWSL and AWCA media), SP-NYGA and SP-M9 (obtained from BV801 grown in rich and minimal control media), and two commercial reference inducers, Actigard® 50 GS (acibenzolar-S-methyl) and Messenger Gold® (commercial harpin formulation). Plants were treated 48 h before pathogen inoculation. SDS-PAGE revealed protein bands in the 12–26 kDa range that were enriched in SP-AWSL and SP-AWCA relative to the control-media preparations. Several BV801-derived preparations produced localized necrosis in N. tabacum leaves consistent with a hypersensitive-response-like reaction. SP-AWSL and SP-AWCA reduced BSX severity in chili pepper by up to 67% compared with the diseased control (Kruskal–Wallis, p ≤ 0.05) and significantly reduced bacterial proliferation (Tukey, p ≤ 0.05). At the final sampling point, plants pretreated with BV801-derived protein preparations and subsequently challenged with X. euvesicatoria showed higher CaBPR1 expression than corresponding pretreated but unchallenged plants, a pattern consistent with a priming-like defense response. These findings support the potential of BV801-derived protein preparations obtained under putative Hrp-inducing conditions as candidates for sustainable resistance-inducing strategies against bacterial spot in chili pepper.

Horticulturae doi: 10.3390/horticulturae12091108

Authors: Manjulatha Mekapogu So-Hyeon Lim O-Hyeon Kwon Youn-Jung Choi Yae-Jin Kim Jae-A Jung

High temperature (HT) is a crucial environmental factor influencing floral pigmentation and ornamental quality in chrysanthemum (Chrysanthemum morifolium) by modulating anthocyanin biosynthesis. In this study, comparative transcriptome profiling was performed in two F1 chrysanthemum lines (RO72 and RO99) under high-temperature stress to elucidate the molecular mechanisms behind heat-induced floral color fading. Analysis revealed extensive transcriptional reprogramming of genes associated with anthocyanin metabolism, hormonal signaling, and oxidative stress responses. While structural genes in the anthocyanin biosynthetic pathway (CHS, DFR, ANS, 3MAT and LDOX) were significantly downregulated, key glycosylation-related genes such as UFGT were upregulated, suggesting a compensatory mechanism that enhances pigment stabilization rather than de novo synthesis. This study identified a shift in the MYB–bHLH–WD40 regulatory complex, specifically the upregulation of transcriptional repressors (MYB62, MYB15) and downregulation of activators (MYB106, bHLH49), suggesting a suppressed anthocyanin accumulation. Simultaneously, genes associated with several signaling cascades such as ROS, ABA, and auxin–jasmonate signaling pathways were differentially expressed, suggesting that these alterations may contribute to the repression of pigment biosynthesis and color fading. Collectively, these results hypothesize that high temperature suppresses anthocyanin accumulation through a dual mechanism of transcriptional inhibition and hormonal modulation, while simultaneously promoting pigment stabilization via glycosylation. This study therefore provides fundamental insights into thermal regulation of floral pigmentation and identifies candidate genes and pathways potentially involved in heat-induced floral color fading in chrysanthemum.

Horticulturae doi: 10.3390/horticulturae12091107

Authors: Gábor Sándor Vértes István Fazekas Márta Ladányi György Lukácsy Marianna Mile Diána Ágnes Nyitrainé Sárdy

To mitigate the potential drawbacks of late pruning, this study evaluated an alternative approach utilising the anatomical features of the umbrella trellis system, cane pruning, and apical dominance. Vine canes were tied at four distinct phenological stages: before budburst, at the 3-leaf, 5-leaf, and 7-leaf stages (BBCH 00, 13, 15, and 17, respectively). We hypothesised that exploiting apical dominance would allow distal buds to burst first; subsequent arching and tying of the cane would then trigger the burst of the remaining basal buds with a temporal delay. The effects of these treatments were evaluated based on leaf area index (LAI), canopy porosity and structure, fertility coefficients, and yield components, supplemented by must composition analysis at harvest and compared alongside a traditional late-pruned cordon-system evaluated under identical phenological timings. Our findings indicated that delayed tying treatments on umbrella-trained vines did not affect canopy structure, resulted in higher yields, greater average bunch weights, without inducing the negative side effects reported for late pruning cordon-trained vines. Regarding final must composition, the treatments produced minor and inconsistent variations, with no significant differences across most measured parameters at harvest.

Horticulturae doi: 10.3390/horticulturae12091106

Authors: Yilin Yuan Su Yan Tong Li Pufan Zheng Yuanzhi Shao Wen Li Na Zhang Jinze Yu Yinghe Sun Ning Liu Jixin Bai Cunkun Chen Xiaoxue Li

Melon (Cucumis melo L.) is a globally significant horticultural crop whose fruit quality and postharvest shelf life are profoundly influenced by oxidative stress. Abscisic acid (ABA)-responsive element binding factors (ABFs), which represent the Group A subfamily of the basic leucine zipper (bZIP) transcription factor family, serve as pivotal components in the ABA signaling pathway. These factors play essential roles in regulating plant responses to abiotic stress as well as fruit development and maturation processes. In this study, a total of nine CmABF gene family members (CmABF1–CmABF9) were successfully identified within the melon genome using genome-wide identification techniques. Bioinformatic analysis indicated that all CmABF proteins contain a conserved bZIP domain. Physicochemical property analysis revealed that most of these proteins are unstable hydrophilic proteins and all are localized to the cell nucleus. Phylogenetic analysis categorized the CmABF family into three distinct evolutionary branches (Groups A, B, and C), exhibiting high conservation with homologous genes in Arabidopsis thaliana, Solanum tuberosum, and other species. Promoter analysis demonstrated that CmABF genes are rich in hormone-responsive elements (such as abscisic acid-responsive element (ABRE) and gibberellin-responsive element (GARE)) and stress-responsive elements (such as MYB binding sites (MBS) and anaerobic-response element (ARE)). To investigate their responses to oxidative stress and ABA signaling, we analyzed the expression patterns of these genes in melon fruit at 0, 7, 14, 21, 28, and 35 days of postharvest storage under ozone (O3, an oxidative stressor), exogenous abscisic acid (ABA), and the ABA synthesis inhibitor nordihydroguaiaretic acid (NDGA) using RNA-seq and qRT-PCR. The results showed that ozone treatment significantly induced the up-regulation of CmABF9 while inhibiting the early expression of CmABF2 and CmABF4. ABA treatment generally promoted the transcription of family members during the late stages of storage (35 d). NDGA treatment suppressed the expression of CmABF2 and CmABF4 during the early storage stage (7 d), while markedly increasing their expression levels at later storage stages (28 d and 35 d), suggesting a compensatory feedback response under endogenous ABA deficiency. Furthermore, protein–protein interaction predictions indicated potential close interactions between CmABF proteins and SnRK2 protein kinases. This study provides a theoretical basis for elucidating the molecular mechanisms of the CmABF family in regulating postharvest oxidative stress in melon and provides candidate gene resources for molecular breeding aimed at enhancing resistance and extending the shelf life of melon fruit.

Horticulturae doi: 10.3390/horticulturae12091105

Authors: Jipeng Qu Chunbang Ding Zhenyong Chen Zhou Xu Zhihan Feng Zhaoguo Tong Zhengsong Peng Shiling Feng Tao Chen Zeshen Yang

Investigating genetic diversity is a prerequisite for the management and utilization of germplasm resources. This study assessed the genetic diversity and population structure of 103 olive (Olea europaea) varieties in the Liangshan region, Sichuan Province, China, based on fruit phenotypic traits and 48 simple sequence repeat (SSR) markers. There were high positive correlations between various fruit phenotypic indicators, while a few indicators showed negative correlations (e.g., stone longitudinal diameter was significantly negatively correlated with the fruit shape index and kernel shape index). Fresh fruit oil content was significantly negatively correlated with fruit longitudinal diameter, stone transverse diameter, stone longitudinal diameter, and fruit volume. The number of allelic variations at SSR loci in the population ranged from 2 to 22, with an average of 10.7. The mean Shannon’s information index (I), observed heterozygosity (Ho), and expected heterozygosity (He) of the 103 varieties were 1.529, 0.54, and 0.685, respectively, indicating relatively high genetic diversity between these olive varieties. Structure analysis, PCA, and PCoA consistently classified the varieties into two ancestral populations, with mean fixation index (FST) = 0.052 and gene flow (Nm) = 4.544, suggesting moderate genetic differentiation and extensive gene flow between the populations. Based on phenotypic clustering and phylogenetic analysis, eight varieties exhibiting synonymy or homonymy were successfully identified. Furthermore, molecular fingerprint profiles were established using seven pairs of SSR primers, which could effectively identify all varieties. This study provides a valuable reference for the management and breeding of olive germplasm resources in the Liangshan region.

Horticulturae doi: 10.3390/horticulturae12091104

Authors: Eryang Pan Changwei Zhang Hongfang Zhu Pan Chen Tong Pang Chenyu Chen Yaolong Wang Dong Xiao

Leaf senescence negatively impacts yield and postharvest quality in non-heading Chinese cabbage (Brassica rapa ssp. chinensis), and the STAY-GREEN (SGR) homologs BcSGR1 and BcSGR2 function as core regulators of chlorophyll degradation. In this study, we constructed CRISPR/Cas9 single- and dual-gene editing vectors using four high-efficiency, high-specificity single-guide RNAs (sgRNAs). By optimizing the transformation system using petiolate cotyledon explants supplemented with 6 mg·L−1 AgNO3, we obtained a PCR-positive transformation efficiency of 26% (this value reflects transformation efficiency; the actual gene editing efficiency for each mutant line is presented in the target sequencing results) and generated BcSGR1 (YB1) and BcSGR2 (YB2) single mutants and a BcSGR1/BcSGR2 double mutant (DKO). All mutant lines exhibited a pronounced stay-green phenotype and delayed leaf senescence. The DKO line produced 3.15-fold higher chlorophyll and only one-quarter of the wild-type MDA level, indicating an additive enhancement effect of the double knockout. Compared with the wild type (3-day shelf life), YB1, YB2 and DKO extended postharvest longevity to 7, 8 and 11 days, with senescence delayed by 15, 18 and 22 days, respectively. Notably, whereas the YB1 and YB2 displayed mild leaf shriveling at later developmental stages, the DKO maintained normal leaf morphology. Collectively, our findings demonstrate that dual editing of BcSGR1 and BcSGR2 exerts an additive effect on delaying leaf senescence and enhances postharvest shelf life without incurring significant yield penalties under the experimental conditions. This study provides a feasible and effective strategy for breeding stay-green cultivars of non-heading Chinese cabbage.

Horticulturae doi: 10.3390/horticulturae12091103

Authors: Eliana Nutricati Alessandro Frontini Erika Sabella Luigi De Bellis Andrea Luvisi Rita Annunziata Accogli Carmine Negro

With the intention of investigating in further depth the horticultural biodiversity resulting from the selection and conservation effort carried out by farmers (custodians) who are dedicated to growing traditional products, we focused on six local landraces of Brassica rapa L. subsp. sylvestris (L.) Janch.; we conducted analyses addressing the presence of glucosinolates (GLSs), phenolic compounds and the antioxidant capacity of extracts of B. rapa landraces belonging to three groups with different growth phase behavior from planting to inflorescence appearance in the Salento area (Puglia or Apulia region, Italy). The studies focused on three local landraces known by Salento farmers as cima di rapa cinquantina (two separate accessions, 50SC and 50SD), cima di rapa sessantina (accessions 60SC and 60SD) and rapacaula (accessions rcSD and rcGA). We revealed the presence of eleven different glucosinolates and three main flavonoids, such as kaempferol, quercetin and isorhamnetin derivatives. The distribution and content of glucosinolates and flavonoids varied widely among the different landraces. Glucobrassicanapin was the predominant compound in all landraces, followed by gluconapin, except for 60SC, where the main GLS was the indolic glucobrassicin. Moreover, 50SC, 50SD and 60SC are characterized by the highest flavonoid content and the highest antioxidant capacity. The findings provide the basis for the characterization of B. rapa subsp. sylvestris L. local landraces as a useful source of valuable metabolites for human health, as well as for identifying one landrace with higher nutritional value as a starting point for accession conservation and economic development.

Horticulturae doi: 10.3390/horticulturae12091102

Authors: Liu Yang Manqi Wu Yali Feng Qian Cheng Jie He Jia Peng Yiwei Tang Yuqi Huang Shuhan Dong Chunyan Liu

Arbuscular mycorrhizal fungi (AMF) have been widely recognized for their ability to enhance plant drought tolerance. However, the contribution of improved phosphorus (P) nutrition to AMF-mediated drought tolerance in citrus and its relationship with other physiological processes remain unclear. Here, we investigated the physiological mechanisms underlying AMF-mediated drought tolerance in trifoliate orange (Poncirus trifoliata) by combining AMF inoculation with exogenous phosphorus supplementation under drought stress. AMF inoculation markedly alleviated drought-induced growth inhibition, increased plant biomass, enhanced root and rhizosphere phosphatase activities, promoted phosphorus accumulation, and strongly induced the expression of the mycorrhiza-specific phosphate transporter genes PtaPT4 and PtaPT5. Exogenous phosphorus supplementation largely mimicked the beneficial effects of AMF on plant growth and drought tolerance, indicating that enhanced phosphorus acquisition contributes substantially to AMF-mediated drought tolerance in trifoliate orange. However, the combined application of AMF and exogenous phosphorus conferred greater drought tolerance than phosphorus supplementation alone, suggesting that, in addition to improved phosphorus nutrition, AMF further enhances drought adaptation through the regulation of multiple physiological processes. Furthermore, AMF promoted the accumulation of growth-related phytohormones, enhanced antioxidant capacity, and reduced reactive oxygen species (ROS) accumulation, thereby further improving plant drought tolerance. These findings demonstrate that enhanced phosphorus acquisition is an important component of AMF-mediated drought tolerance in trifoliate orange, whereas coordinated regulation of phytohormone homeostasis and antioxidant defense provides additional protection against drought stress.

Horticulturae doi: 10.3390/horticulturae12091100

Authors: Rui-Heng Yang Cai-Hong Li Yun-Yi Wang Chen-Zhao Zhu Ting Guo Yan Li Guang-Yan Ji Yang Cao Da-Peng Bao Jun-Jun Shang

The diversity of ACC deaminase-producing bacteria in the casing soil of Phlebopus portentosus and their roles in fruiting body development were investigated in this study. The dynamic succession of the functional microbial community in casing soil at different developmental stages, including the original casing soil (FT), mycelial stage (JS), pinhead stage (EJ), primordium stage (YJ), and harvest stage (CS), was analyzed by acdS gene high-throughput sequencing, enrichment isolation, and co-culture assays. The results showed that the richness and diversity of the acdS gene community were highest in the JS samples, and then decreased significantly at the EJ and CS stages. Proteobacteria became the dominant phylum after fruiting body formation, and its relative abundance reached 99%. In contrast, the relative abundance of Actinobacteria decreased significantly. At the genus level, Burkholderia and Paraburkholderia were dominant across all developmental stages. A total of 177 ACC deaminase-producing bacterial strains were isolated through enrichment cultivation, all of which belonged to the genus Burkholderia. Co-culture assays showed that 10 representatives of these strains significantly promoted mycelial growth, primordium formation, and fruiting body yield. The maximum yield increase reached 54%. This study is the first to systematically reveal the succession pattern of ACC deaminase-producing bacteria in the casing soil of P. portentosus. It provides an important basis for elucidating the molecular mechanism by which casing soil microbiota promotes fruiting body development.

Horticulturae doi: 10.3390/horticulturae12091101

Authors: Mladen Kalajdžić Sara Todorić Dragoslav Ivanišević

After harvest, table grape berries undergo physical and chemical changes even with optimal storage conditions, and postharvest fruit quality retention varies among varieties. This study evaluated four varieties over a two-year period: Lasta, Lyana, recently released seedless variety Nada, and the widely cultivated Muscat Hamburg. At harvest, variety x year interaction affected yield, berry weight, and berry size, while differences among varieties were observed for rachis weight (p < 0.001) and the number of berries per cluster. During storage and shelf life, analyzed separately by experimental year, no berries with mechanical disorders or decay incidence were observed. Weight loss increased during storage in all the varieties, and this was particularly pronounced during the shelf-life period. Berry firmness ranged from 5.7 to 27.8 N/mm2 depending on variety and storage duration. After 28 days of cold storage, increased berry firmness compared with harvest was recorded only in variety Nada. In 2024, Nada exhibited the highest total soluble solids content at harvest and, after 28 days of cold storage, reached 28.2%, significantly exceeding its harvest value and the SSC of the other varieties at the same evaluation time. Varieties showed different potential for cold storage. After 28 days in cold storage, sensory acceptance scores for Lasta and Nada decreased significantly compared to harvest, mainly due to increased rachis browning and berry skin shriveling. Muscat Hamburg showed the lowest rachis browning during storage. This study demonstrates the importance of selecting table grape varieties adapted to diverse environmental conditions and capable of maintaining postharvest quality during cold storage and shelf life.

Horticulturae doi: 10.3390/horticulturae12091099

Authors: Yu Zhuang Jiayuan Zhu Zhanpeng Luo Yahui Tian Meng Yin Haoyi Wang Yijia Wang

During cherry-tomato-bunch harvesting, clustered fruits, thin stems, and ambiguous fruit–stem junctions cause missed detections and errors in picking-point localization. To address these challenges, we propose TSP-Net, a structure-aware and geometry-constrained detection network built on YOLOv11n, together with an ROI heat-map regression module for picking-point localization. TSP-Net integrates the Truss-aware Multi-scale Ghost Cross Stage Partial (TMG-CSP) module into the backbone to strengthen structural features of fruit edges, small stems, and clusters. It introduces the Truss-oriented Axial-Local Attention (TALA) module during feature fusion to capture fruit-arrangement direction and local occlusion boundaries. We also design Physics-informed Truss Consistency (PTC) Loss to regularize detections by enforcing consistency with fruit-cluster morphology through constraints on center distribution, inter-fruit spacing, and scale continuity. For picking-point localization, local ROIs are extracted from detection outputs, Gaussian heat maps are predicted, and continuous coordinates are decoded using soft-argmax. In the controlled evaluation, TSP-Net attains precision 81.81%, recall 73.21%, mAP@50 79.53%, and mAP@50:95 64.83%, which exceed the corresponding YOLOv11n results by 0.83, 0.32, 1.29, and 1.03 percentage points, respectively. The model size is reduced from 5.23 MB to 5.08 MB, the parameter count falls from 2.59 M to 2.49 M, and computational cost declines from 6.4 to 6.0 GFLOPs. On the common valid-ROI test set, the proposed heat-map localization yields a mean localization error of 47.2 px, a median error of 24.2 px, and PCK@20, PCK@50, and PCK@100 of 45.1%, 68.4%, and 85.5%, respectively. Under identical ROI conditions, this heat-map method reduces the mean localization error by 11.3 px and raises PCK@20 by 14.9 percentage points compared with direct coordinate regression. In summary, the proposed approach enhances cherry-tomato-bunch detection and 2D picking-point candidate localization while meeting lightweight constraints, offering a structure-aware visual perception solution for greenhouse cherry-tomato harvesting.

Horticulturae doi: 10.3390/horticulturae12091098

Authors: Hailun Liu Yonghua Jiang Fachao Shi Yingjie Wen Hua Huang Zhenrui Huang Qian Yan

Lychee (Litchi chinensis Sonn.) is a major subtropical fruit crop, yet the regulatory hierarchy underlying edible ratio (flesh weight/whole fruit weight, %) and juice yield (juice weight/whole fruit weight, %), the core processing-quality traits, remains unresolved. We phenotyped 301 accessions from ten origins under uniform conditions and used hierarchical regression to predict and evaluate edible ratio and juice yield based on structural and physiological fruit traits, thereby separating the contributions of structural constraints and physiological modulation. Both traits exhibited broad population variation and were significantly modulated by maturity stage, with late-maturing accessions outperforming early types. A strong positive correlation (r = 0.679, p < 0.001) supported the identification of “double-high” germplasm combining superior edible ratio and juice yield. Kernel ratio emerged as the dominant structural constraint on edible ratio (R2 = 0.6699, p < 0.001), while the combined inedible fraction served as the basal limiting factor for juice yield (R2 = 0.4262, p < 0.001). Critically, after controlling for structural variation, physiological traits contributed an independent 9.2% of explained variance (ΔR2 = 0.092, p < 0.001). pH was identified as the primary positive physiological predictor (β = 0.322, p < 0.001), whereas soluble solids content (SSC) exhibited a weak negative effect (β = −0.064, p = 0.008), indicating that high sugar content is not a priority target for processing-oriented breeding. An Integrated Ideotype Score (IIS) was constructed to objectively rank germplasm; elite accessions including ‘10_269’, ‘Yujinqiu’ and ‘Nuomici’ combined edible ratio > 75% with juice yield > 40%. These findings establish a “structural constraint-physiological modulation” two-tier regulatory hierarchy for lychee processing quality and provide a multivariate framework for germplasm evaluation and breeding selection.

Horticulturae doi: 10.3390/horticulturae12091097

Authors: Yanxiu Miao Junxuan Lin Jun Zhang Zhihao Zeng Qiong Shen Yongsan Cheng Bin Li

Accurate prediction of the net photosynthetic rate (Pn) is important for understanding crop responses to environmental conditions in protected cultivation. The Pn responds nonlinearly to the temperature, photosynthetic photon flux density (PPFD), and CO2 concentration, making accurate prediction under combined environmental conditions challenging. However, these effects make it difficult for mechanistic models to precisely predict the Pn. In this study, 1800 repeated Pn records of zucchini leaves were obtained during flowering and fruiting stages and used to construct and evaluate a GA-optimized adaptive neuro-fuzzy inference system (GA-ANFIS), ANFIS, random forest (RF), and radial basis function (RBF), as well as backpropagation (BP) models. The maximum Pn values were 43.22 and 45.21 μmol·m−2·s−1 during flowering and fruiting, respectively, at 32 and 28 °C, a PPFD of 1800 μmol·m−2·s−1, and a CO2 concentration of 1200 μmol·mol−1. On the test set, the GA-ANFIS achieved R2 values of 0.9811 and 0.9901 and RMSE values of 1.4808 and 1.1889 μmol·m−2·s−1, respectively. It also achieved the highest R2 and lowest RMSE on the additional temperature interpolation set. The test set regression slopes were 0.9876 and 1.0001, with intercepts of 0.1060 and −0.0465. Overall, the GA-ANFIS showed the best predictive performance among the five models under the evaluated conditions.

Horticulturae doi: 10.3390/horticulturae12091096

Authors: Francisco José Aznar-Garrido Alejandro López-Martínez

Almería’s high-yield Mediterranean agricultural model is based fundamentally on eight main greenhouse vegetables, with tomato, peppers, and cucumber identified as the principal crops. To facilitate regional diversification, the biological adaptation and techno-economic viability of Vanilla planifolia are examined. The physiological requirements of this orchid, an obligate CAM plant, regarding light intensity and water-use efficiency highlight the need to implement active heating systems, a double internal roof, high-density shading, and misting to emulate the tropical conditions required for this crop in Mediterranean-climate greenhouses. Globally, the market value fell from 898 million USD in 2020 to nearly 328 million USD in 2025, revealing extreme price volatility. Around 75% of global production is absorbed by European and North American markets. While primary production is concentrated in Madagascar, Indonesia, Uganda, and Papua New Guinea, strategic commercial roles are maintained by traders in non-producing nations such as France, the Netherlands, and Germany. Between 2022 and 2024, a systemic collapse was recorded in export revenues. During this period, mean prices fell from 130.83 USD/kg to 44.57 USD/kg. In 2025, wholesale prices rose slightly to 48.59 USD/kg, and global vanilla demand stands at around 6760 t, a volume similar to that of previous years. Viable cultivation of Vanilla planifolia in southeastern Spain and processing it into cured pods are favored by its geographical proximity to European markets. This strategic positioning can ensure optimal harvest maturity and achieve superior biochemical quality through the incorporation of agro-industrial procedures. This information will provide the knowledge necessary to design a field trial aimed at validating Vanilla planifolia as a crop of interest for Mediterranean greenhouses.

Horticulturae doi: 10.3390/horticulturae12091093

Authors: Chloe Seeborg Melanie Stock Claudia Nischwitz Xin Dai Cambry Adams Burdette Barker

Irrigation guidelines are needed for the field production of emerging specialty crops to support the sustainability and economic viability of small farms. The goal of this study was to establish crop coefficients (Kc) of dahlia (Dahlia × hybrida), a popular, profitable cut flower crop, while documenting virus infection. A two-year field study was conducted with two industry-important cultivars that vary in production timing and bloom: ‘Boom Boom White’, an earlier and mid-sized formal decorative, and ‘Café au Lait’, a later and large informal decorative bloom type. A field water balance was used to evaluate five irrigation rates (I), as a percentage of the estimated crop evapotranspiration, ETc: 100% of ETc (I100), two deficit irrigation (DI) rates of 80 and 60% (I80 and I60), and two regulated deficit irrigation (RDI) rates during the vegetative stage (I80/100 and I60/100). The Kc of both cultivars were 1.0 during the vegetative stage and 1.1 during the reproductive stage and estimated to be 0.7 during establishment. Both DI and RDI delayed and reduced yields, while virus infection led to cultivar-specific responses. ‘Café au Lait’ had greater sensitivity to viral infection and water stress, particularly when under co-infection with two or more viruses; this occurred for ‘Boom Boom White’ with three viruses.

Horticulturae doi: 10.3390/horticulturae12091095

Authors: Chang Zhang Xu Wang Yuanfeng Zhan Chengdong Jiang Can Kong Sheng Shu

Continuous cropping in tropical protected cultivation can impair soil health and increase the risk of soil-borne disease. We conducted a single-season field comparison in Hainan (October 2025–February 2026) to characterize the performance and rhizosphere microbial profiles of the mini-watermelon cultivar ‘Meiyue’ grown either on its own roots or grafted onto Cucurbita ficifolia. Plant growth, leaf gas exchange, fruit quality, and the field incidence of Fusarium wilt-like symptoms were recorded, and bacterial 16S V3-V4 and fungal ITS2 amplicons from the rhizosphere were sequenced. Grafted plants were taller and had thicker stems and longer internodes. Leaf chlorophyll content, stomatal conductance, and intercellular CO2 concentration were higher in grafted plants, whereas net photosynthetic rate did not differ between treatments. Wilt-like symptoms occurred in 55.41% of own-rooted plants, while no grafted plants developed symptoms during the trial. Mean single-fruit weight was 2.8-fold higher in the grafted treatment; grafted fruits were also larger and had a higher central soluble solids content. Bacterial and fungal beta diversity did not differ significantly between treatments (PERMANOVA, p = 0.100), although several taxa differed in relative abundance and LEfSe identified treatment-associated biomarkers. An exploratory functional-profile sensitivity analysis, performed after excluding one high-leverage own-rooted replicate, indicated modest differences in predicted nitrogen-transformation functions and fungal trophic modes; these predictions were not subjected to inferential testing. Correlations between microbial relative abundance and fruit traits were interpreted as associations rather than evidence of function. Within the constraints of a single-season, two-treatment study, watermelon grafted onto C. ficifolia showed better field performance and treatment-associated shifts in selected rhizosphere taxa under continuous-cropping conditions.

Horticulturae doi: 10.3390/horticulturae12091094

Authors: Chuanbao Wu Junman Zhou Chen Feng Naiyu Wang Xiaoming Zhang Jing Wang Wei Wang Kaichun Zhang Hui Yuan Xuwei Duan

Sweet cherries are an important temperate fruit crop, and protected cultivation has expanded rapidly in recent years. However, unstable fruit set under protected cultivation remains a major challenge, and the application of fruit set enhancement treatments has become common practice in commercial production to stabilize and improve fruit set performance. Various fruit set enhancement treatments, including biotic pollination and hormonal regulation, have been shown to influence source–sink relationships through different physiological pathways, thereby affecting fruit set rate and fruit quality. In this study, three fruit set enhancement treatments, namely hand pollination (HP), plant growth regulator treatment (PGRT), and bee pollination (BP), were applied, with an untreated control (CK) included for comparison, to evaluate their effects on fruit set rate and fruit quality in the self-compatible sweet cherry cultivar ‘Sunburst’ under protected cultivation. Both HP and PGRT significantly increased fruit set rate by 33.47 and 27.84 percentage points, respectively, compared with CK (71.68% and 66.05% vs. 38.21% in CK), and enhanced fruit firmness (86.50 g and 97.00 g vs. 70.10 g in CK) and raffinose content (0.53 mg g−1 FW and 0.32 mg g−1 FW vs. 0.15 mg g−1 FW in CK). However, PGRT significantly increased pedicel length (3.43 cm vs. 2.81 cm in CK) and gluconic acid content (3.44 mg g−1 FW vs. 2.02 mg g−1 FW in CK), while decreasing ascorbic acid content (0.23 mg g−1 FW vs. 0.34 mg g−1 FW in CK). Although BP resulted in the highest soluble solids content (16.68%) and total phenolic content (1.93 mg g−1), its fruit set rate remained low (42.06%) and was not significantly different from that of CK. Comprehensive evaluation indicated that, whilst ensuring adequate fruit set, hand pollination demonstrated superior overall performance among the evaluated treatments by maintaining desirable fruit appearance and balanced sugar–acid metabolism, serving as a practical, non-chemical, and environmentally safe supplementary fruit set enhancement strategy under the specific greenhouse conditions evaluated.

Horticulturae doi: 10.3390/horticulturae12091092

Authors: Huimin Li Yuhang Shi Baoxia Liu Jiashun Miao Yan Chun Haimei Yue Na Liu

Pea root rot is a major soil-borne disease that threatens global pea production. In this study, diseased pea root samples were collected from Zhejiang Province for pathogen isolation and identification. The mycelial growth rate method was used to evaluate the sensitivity of the pathogens to different fungicides, and transcriptome analysis was performed to investigate the response mechanisms underlying pea root responses to pathogen infection. A total of eight fungal pathogens were identified, including Fusarium solani, F. commune, F. oxysporum, F. proliferatum, F. tricinctum, F. andiyazi, Alternaria alternata, and Didymella pinodella. Among them, F. solani and F. commune were the dominant pathogens. Both pathogens showed high sensitivity to prochloraz, with EC50 values of 0.051 and 0.030 mg·L−1, respectively. Transcriptome sequencing revealed that peas respond to pathogen infection through pathways related to secondary metabolism and plant hormone signal transduction. Furthermore, 14 candidate genes potentially involved in resistance to pea root rot were screened.

Horticulturae doi: 10.3390/horticulturae12091091

Authors: Luca Regni Nicola Cinosi

Fruit tree cultivation plays a central role in the economies, diets, and cultural traditions of many regions worldwide, but it is increasingly challenged by climate change, rising production costs, and the growing demand for sustainable and high-quality products [...]

Horticulturae doi: 10.3390/horticulturae12091090

Authors: Lixia Gu Liping Zhao Yan Bai Wanxing Hu Huimin Peng Jingjing Wang Hangkong Liu Ning Li Haijun Gong

Drought stress can promote early flowering in plants. However, the mechanism remains not well understood. Here, we investigated the role of the ascorbate redox ratio in regulating tomato flowering under polyethylene glycol-6000 (PEG)-induced osmotic stress, which mimics drought. The results showed that compared with the control, a drought stress at 45% substrate water content promoted tomato flowering, while 25% water content did not affect flowering. Under simulated drought induced by PEG, early flowering was only observed under 10% PEG, while lower or higher PEG concentrations did not affect flowering. Under 10% PEG, the expressions of flowering integrator genes (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 and SINGLE FLOWER TRUSS) and meristem identity genes (APETALA1 and LEAFY) were up-regulated, while they were largely unchanged or down-regulated under 20% PEG. The dehydroascorbic acid (DHA)/reduced ascorbic acid (AsA) ratio was increased under 10% PEG but remained unchanged under 20% PEG. Foliar DHA treatment increased the DHA/AsA ratio in leaves, promoted tomato flowering, and up-regulated the expressions of flowering integrator and meristem identify genes in the control conditions, while foliar AsA treatment demonstrated the opposite phenotype under 10% PEG. In addition, foliar treatment with N,N′-dimethylthiourea, a reactive oxygen species scavenger, decreased the DHA/AsA ratio in leaves and delayed tomato flowering under 10% PEG. The expression patterns of genes in the photoperiod, vernalization, autonomous, ambient temperature, and age pathways did not provide evidence for their involvement in osmotic stress-induced early flowering in the present sampling conditions. Our results suggest that osmotic stress-induced H2O2 accumulation increased the DHA/AsA ratio in plants, which promoted tomato flowering. The study may help clarify the mechanism for drought-induced flowering in plants.

Horticulturae doi: 10.3390/horticulturae12091089

Authors: Zhi Qiu Zhaomin Shi Yuechao Sun Deyun Mo Xingzao Ma Guangbin Wang Caimao Su

At present, the diagnosis of pitaya diseases is chiefly dependent on human expertise, a process that is plagued by issues such as low identification efficiency and high subjectivity. In order to achieve rapid and accurate identification of diseases that are prevalent in pitaya, this paper focuses on such diseases and proposes a machine-vision detection method based on an improved YOLO11n algorithm. The enhanced architecture incorporates MSCAM for edge-feature enhancement, ACmix to balance local and global perception, and PMHSA to optimize deep semantic flow, collectively addressing the challenges of small-target loss and false positives in pitaya disease detection. The experimental findings demonstrate that the improved model attains a detection accuracy of 95.8%, a recall rate of 92.3%, and an mAP50 of 95.9%. A comparison of the baseline model with the improved model reveals a reduction in the number of parameters representing a decrease of approximately 14.2%. Furthermore, the computational complexity indicates a decline of approximately 3.07%, and a reduction in model size by approximately 4.73%. This approach led to enhanced disease-recognition performance while preserving high levels of accuracy. This study proposes a technically sound solution for the intelligent development of disease-detection models for pitaya.

Horticulturae doi: 10.3390/horticulturae12091088

Authors: Muhammad Tahir Naseem Wajid Zaman

Soilless systems are increasingly important in protected horticulture because they improve water and nutrient-use efficiency, support year-round production, and reduce dependence on field conditions. However, the root zone is still commonly managed as a passive nutrient reservoir using mainly electrical conductivity and pH set points. This review presents the root zone as an actively engineered biological environment in which dissolved oxygen, root-zone temperature, nutrient-solution chemistry and hydraulics, microbiomes and biofilms, and sensor-guided control interact to determine crop performance. These domains converge on root respiration and ATP production, membrane transport, aquaporin activity, hydraulic conductance, calcium delivery, oxidative balance, and microbial or pathogen selection. Their combined effects influence fresh mass, tissue hydration, nutrient uptake, phytochemical composition, tipburn incidence, disease resilience, and overall system stability. Recent evidence indicates that active aeration, targeted root-zone heating or cooling, optimized flow scheduling, and calcium-focused interventions can improve the yield and quality of leafy vegetables, although responses vary with crop species, cultivar, developmental stage, and production-system architecture. Current evidence also indicates important uncertainties, including crop- and cultivar-specific response thresholds, architecture-dependent performance, energy and resource costs, and the still-limited predictability of microbiome manipulation. Emerging sensing, machine learning, digital-twin, and predictive-control approaches could enable a transition from threshold-based correction to physiology-informed root-zone state management. Nevertheless, wider commercial translation is constrained by inconsistent reporting of sensor location, hydraulic conditions, nutrient composition, microbial status, and resource use. We therefore propose a minimum reporting framework and research priorities for developing reproducible, energy-aware, microbiologically robust, and crop-specific root-zone management strategies for closed soilless horticulture.

Horticulturae doi: 10.3390/horticulturae12091087

Authors: Huiwen Zhang Dongliang Zuo Xiaoshuang Zhang Mohan Li Beibei Gong Ruxuan Guo Gang Li Kai Su Xiaoying Li Chunsheng Liu Xiao Xiao Junkai Wu Libin Zhang Chenguang Zhang

Low temperatures are a major environmental factor limiting the growth and productivity of peaches (Prunuspersica). U-box E3 ubiquitin ligases (PUBs) are known to play a role in plant responses to abiotic stresses; however, their role in cold tolerance of peaches is unclear. In this study, transcriptome data revealed that a U-box E3 ubiquitin ligase gene, PpPUB20, was significantly activated by low temperatures. Expression analysis showed that PpPUB20 was rapidly upregulated under cold stress, with a more pronounced early response in cold-tolerant cultivars than in the cold-sensitive cultivars. Phylogenetic analysis revealed that PpPUB20 is evolutionarily conserved across plant species, and domain prediction identified a highly conserved U-box domain. Functional assays demonstrated that overexpressing PpPUB20 gene significantly enhanced low-temperature tolerance in Arabidopsis thaliana, whereas silencing it reduced low-temperature tolerance in peach calli. Physiological studies suggested that PpPUB20 positively regulates cold tolerance by enhancing antioxidant enzyme activity and minimizing membrane damage. Yeast two-hybrid screening identified sorbitol dehydrogenase (PpSDH) as a potential PpPUB20-interacting protein, which was further confirmed by luciferase complementation and co-immunoprecipitation assays. In vitro ubiquitination assays demonstrated that PpPUB20 functions as an E3 ubiquitin ligase mediating the polyubiquitination of PpSDH. This study found that an alternatively spliced transcript of PpPUB20 was present in the non-cold-resistant variety ‘21 Shiji’ but absent in the cold-resistant variety ‘Shijizhixing’. These splicing variants show functional deficiencies in their response to low-temperature stress and its substrate protein interaction due to an absent ARM domain. Full-length and structurally intact PpPUB20 was ubiquitinated by targeting PpSDH, thereby regulating sorbitol metabolism and enhancing the low-temperature tolerance of peaches. This study reveals a new molecular mechanism of peach response to low-temperature stress and further emphasizes the important role of ubiquitination-mediated post-translational regulation in the environmental adaptability of fruit trees.

Horticulturae doi: 10.3390/horticulturae12091085

Authors: Yueping Zheng Yan Lin Shaofeng Cui Minhui Chen Yakun Liu Chunyu Wang Yujun Hu Tian Pan Hongbo Liu Yi Gan Zhifu Zheng Yihua Zhan

Plastid-localized glycerol‑3‑phosphate acyltransferase (ATS1) catalyzes the initial acylation step in the prokaryotic branch of glycerolipid biosynthesis and is pivotal for membrane lipid remodeling. In this study, we investigated the role of Arabidopsis thaliana ATS1 (AtATS1) in salt tolerance using transgenic Brassica napus lines overexpressing AtATS1 and wild-type plants. Under 150 mM salt stress, AtATS1-overexpressing lines exhibited significantly compromised tolerance, characterized by severe growth inhibition and cotyledon abscission compared to wild-type plants. Physiological assays further revealed that despite a hyper-induction of antioxidant enzymes (SOD and POD), the transgenic lines suffered from excessive reactive oxygen species (ROS) accumulation and elevated malondialdehyde (MDA) levels, indicating a failure to maintain redox homeostasis. Transcriptomic analysis demonstrated that AtATS1 overexpression disrupts the stress response by misallocating metabolic resources toward glucosinolate biosynthesis and constitutively repressing the MAPK signaling cascade (including WRKY42, MPK15, and MEKK1). In conclusion, these findings identify AtATS1 as a negative regulator of salt tolerance in B. napus. This study provides new insights into the link between lipid metabolism and abiotic stress responses and highlights the need for careful modulation of glycerolipid biosynthesis when engineering salt-resilient rapeseed varieties.

Horticulturae doi: 10.3390/horticulturae12091086

Authors: Sang Rim Kim Yeon Ju Choi Faraaz Ahmed Mohammad Mac Cheryl Sulan Charles Emparang Ji Gu Lee Min Geon Cho Dae Geun Jeong Min Jae Kim Kyung Min Park Jum Soon Kang

Multi-tier hydroponic systems improve land use efficiency in protected strawberry production; however, shading in the lower cultivation tier can substantially limit plant growth, fruit yield, and fruit quality. This study evaluated whether supplemental LED lighting with different spectral compositions could compensate for lower-tier light deficiency in the strawberry ‘Seolhyang’. Plants were grown under an upper-tier control (UT-C), a lower-tier control (LT-C), and four lower-tier supplemental lighting treatments: blue (LT-B), red (LT-R), red + white (LT-RW), and red + white + far-red (LT-RWF). The lower tier received 6–8 mol·m−2·d−1 less daily light integral (DLI) than the upper tier, whereas supplemental lighting increased DLI by approximately 6.5 mol·m−2·d−1. Among the tested spectra, LT-RW consistently produced the greatest improvements in vegetative growth, reproductive performance, fruit quality, and total yield. LT-RW increased total yield from 102.4 g·plant−1 in LT-C to 359.1 g·plant−1, corresponding to 65.6% of the UT-C yield, and achieved an estimated gross margin equivalent to 48.0% of the UT-C level, compared with 18.5% for LT-C. LT-RW also maintained a higher soluble solids content, SSC/TA ratio, fruit weight, and firmness than the other lower-tier treatments. LT-B showed the highest total sugar concentration on a dry-weight basis and the highest ellagic acid content, but these biochemical responses were not accompanied by comparable improvements in overall productivity or fresh fruit quality. LT-RWF showed intermediate performance, whereas LT-R provided only partial improvement. Principal component analysis further suggested that LT-RW produced the overall plant response most similar to that of UT-C. These findings demonstrate that red + white supplemental lighting is an effective strategy for improving lower-tier productivity, fruit quality, and estimated economic performance in multi-tier hydroponic strawberry production.

Horticulturae doi: 10.3390/horticulturae12091082

Authors: Guangzheng Guo Zhuanmiao Kang Qin Zhang Fengping He Wenlin Wang Liang Tao Yuhui Niu Xinghao Tu

The kernel oil content of macadamia can reach up to 80%, yet the molecular basis underlying cultivar-dependent variation in lipid accumulation remains insufficiently understood. In this study, four macadamia cultivars with contrasting oil traits (O.C, QA1, QA2, and QA3) were investigated using integrated transcriptomic, metabolomic, and nutritional analyses to explore the metabolic pathways associated with kernel oil accumulation. Phenotypic evaluation revealed significant differences in fruit characteristics and nutritional composition among cultivars, with O.C exhibiting the highest crude fat content and QA1 showing the highest crude protein content. Transcriptomic analysis identified numerous differentially expressed genes (DEGs), which were mainly enriched in glycerolipid metabolism, α-linolenic acid metabolism, and amino acid biosynthesis pathways. Metabolomic profiling detected 778 metabolites, among which lipid-related compounds represented a major proportion. Integrated analysis revealed three major metabolic pathways associated with oil accumulation, including amino acid biosynthesis, glycerolipid metabolism, and linoleic acid metabolism. In the amino acid biosynthesis pathway, differential accumulation of amino acids and expression changes of genes including ASNS, GLUL, and MAT were observed among cultivars. In glycerolipid metabolism, differential expression of TAG biosynthesis-related genes (DGAT and PDAT) and variation in phospholipid-related metabolites, including LysoPC and LysoPE, were detected among cultivars. In linoleic acid metabolism, differential expression of fatty acid desaturation and elongation genes (SAD, FAD2, FAD3, and FAE1/KCS) was accompanied by cultivar-dependent differences in the abundance of several fatty acid-related metabolites. Overall, this study provides a comprehensive characterization of transcriptomic and metabolic variation associated with crude fat content and fatty acid-related metabolites in macadamia kernels and identifies candidate genes for further functional validation and molecular breeding studies.

Horticulturae doi: 10.3390/horticulturae12091081

Authors: Yue Wang Wenhua Bu Xiaoxuan Feng Jinhui Song Hanru Ma Fangyuan Liu Xiaofei Zhang Peng Wang

F-box proteins typically serve as substrate-recognition subunits of the SCF (SKP1-CUL1-F-box) E3 ubiquitin ligase complex and play key roles in mediating selective protein degradation and regulating diverse biological processes. Cucumber (Cucumis sativus) is a globally important vegetable crop, but it is highly sensitive to heat stress, which severely limits its yield and quality. However, the systematic characterization of CsFBX gene family and its function in thermotolerance remain unclear. Using the high-quality CLv4.0 reference genome, this study identified 175 CsFBX genes and classified them into six clades based on phylogenetic analysis. Chromosomal localization and collinearity analysis revealed that tandem duplication is the main driver of CsFBX family expansion. Promoter cis-element analysis revealed that enrichment of stress-responsive elements in CsFBX promoter regions suggests their potential involvement in abiotic stress responses. Transcriptome profiling under heat stress identified three significantly induced candidate genes: CsFBX25, CsFBX77 and CsFBX87. Transient overexpression of CsFBX25 and CsFBX77 in cucumber led to reduced chlorosis and decreased electrolyte leakage under high temperature. Taken together, this study systematically characterized the CsFBX gene family and identified candidate genes that may contribute to heat stress responses, providing a foundation for future functional investigations.

Horticulturae doi: 10.3390/horticulturae12091084

Authors: Luoyun Wang Hang Yao Yi Yang Xiu Huang Zhenpeng Nie Changjiang Cui Xiaodong Xing Lifang Sun Fuzhi Ke

To investigate the genetic variation underlying the phenotypic differences between Citrus reticulata ‘Bendizao’ and its seedling mutation cultivar Citrus reticulata ‘Dongjiang Bendizao’, we performed whole-genome resequencing of both cultivars using high-throughput sequencing technology, achieving sequencing depths of 22× and 36×, respectively. Compared to the reference genome, we identified 4,150,080 and 4,081,142 single nucleotide polymorphism (SNP) loci in ‘Bendizao’ and ‘Dongjiang Bendizao’, of which only 5.41% and 5.52% were located in exonic regions. Exonic SNPs with nonsynonymous mutations or termination alteration effects yielded 3088 candidate genes. In addition, 664,149 and 627,686 insertions/deletions (InDel) loci were detected in the two cultivars, with only 1.50% and 1.57% in exonic regions, leading to the identification of 1065 genes based on differential exonic InDel loci. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the genetic variations were predominantly enriched in pathways such as RNA polymerase, phenylpropanoid biosynthesis, and plant–pathogen interaction. qRT-PCR validation of the five selected differentially expressed genes confirmed that three of them were significantly upregulated in ‘Dongjiang Bendizao’ compared with ‘Bendizao’, with fold changes ranging from approximately 4 to 13. Future functional validation of key candidates, including members of the TPS21, E2.1.1.104, RPS2, and CNGC genes, will help elucidate their regulatory networks and facilitate stress-tolerance breeding. Collectively, this study provides insights into the genomic variation between the two cultivars and establishes a theoretical foundation for cultivar identification and genetic improvement of local citrus germplasm.

Horticulturae doi: 10.3390/horticulturae12091083

Authors: Huibin Liu Linxiu Liu Yu Sheng Xueyuan Ren Shengsheng Wang Miaomiao Tian Deyi Yuan Lin Cheng

Camellia gauchowensis is widely distributed in South China. Field observations indicate that it produces abundant flowers but yields relatively few fruits under natural conditions. Understanding the intrinsic and extrinsic drivers of this low fruit output is essential both for revealing adaptive strategies in oil-tea camellia and informing cultivation improvement. In this study, we comprehensively investigated the flowering phenology, floral traits, pollen traits, pollinator activity, and breeding-system characteristics of C. gauchowensis. The results showed that C. gauchowensis produces perfect flowers but suffers from a narrow effective pollination window during its late-autumn-to-winter flowering period. Stomium-cell contaminants mixed with pollen grains may contribute to its poor pollen germination capacity. Cytochemical staining (TTC and FDA) significantly overestimated viability compared to in vitro germination results, and thus could not serve as a reliable substitute for functional pollen assessment. Both the outcrossing index and the pollen–ovule ratio indicated that C. gauchowensis exhibits a reproductive tendency toward outcrossing, with its sexual reproduction largely dependent on pollinators. Among the recorded floral visitors, Apis cerana represents the most promising pollinator candidate owing to its numerical dominance, frequent stigma contact, and superior cold-tolerance capacity. Our results reveal that reproductive success in C. gauchowensis is collectively constrained by multiple factors: a narrow effective pollination window, low pollen viability, winter-driven pollinator scarcity, and its reproductive tendency toward outcrossing. This study elucidates the coupled intrinsic–extrinsic mechanisms underlying low fruit output in this winter-flowering oil-tea camellia and provides theoretical underpinnings for pollination management and high-yield cultivation of this economically important woody crop.

Horticulturae doi: 10.3390/horticulturae12091078

Authors: Francisco Leonardo Gomes de Menezes Ricardo Henrique de Lima Leite Francisco Klebson Gomes dos Santos Luiz Paulo de Oliveira Queiroz Adrianus Indrat Aria Edna Maria Mendes Aroucha

This study aimed to evaluate the effect of chitosan/cassava starch/TiO2 coatings on the respiratory activity, physicochemical properties, and commercial/postharvest quality attributes (appearance, odour, colour, fungal incidence, shine, and film adhesiveness) of Hawaiian papaya. Three treatments were evaluated: uncoated papaya (control), papaya coated with chitosan/cassava starch (1:1) (CH/ST), and papaya coated with chitosan/cassava starch (1:1) containing 1% TiO2 (CH/ST/T). The fruits were stored under fluorescent light at 22 ± 1 °C and 80% ± 1% RH, for 18 days. The biopolymeric coatings acted as a physical barrier, reducing the respiratory rate and mass loss, delaying senescence-associated metabolic changes and slowing chlorophyll degradation and carotenoid accumulation. The coatings maintain pulp firmness, soluble solids, titratable acidity, and internal quality, resulting in fruits with superior sensory attributes and greater commercial appeal. The coatings also showed good adhesion to the fruit peel, reduced fungal incidence, and maintained desirable odour, colour, shine, and overall acceptance. The coating containing TiO2 (CH/ST/T) was the most effective in extending the shelf life of papaya by six and nine days, compared to fruits treated with TiO2-free coating (CH/ST) and the uncoated control, respectively.

Horticulturae doi: 10.3390/horticulturae12091080

Authors: Jiayue Xu Yuzhang Yang Yang Ni Tianle Shi Rong Xiong Yuan Yang

Processing quality in chestnut (Castanea spp.) is a complex trait jointly determined by fruit development, postharvest metabolic changes, and responses to processing. However, its genetic basis and regulatory networks remain poorly understood. This review provides an integrated framework linking product-specific processing requirements with their biochemical basis, candidate genes, and molecular breeding strategies. Starch composition and fine structure primarily determine cooked texture, storage hardening, and digestibility; starch degradation and sugar metabolism affect sweetness and thermally induced flavor formation; and phenolic substrates, together with oxidative enzymes, determine browning potential and color stability. We review the biochemical basis underlying these traits and summarize candidate genes and regulatory pathways involved in starch synthesis and structural modification, starch-to-sugar conversion, enzymatic browning, flavor formation, and the accumulation of nutritional and bioactive compounds. Nevertheless, stable quantitative trait loci, favorable haplotypes, and causal genes associated with chestnut processing quality remain insufficiently validated. Future research should develop product-oriented, standardized phenotyping systems and integrate multi-environment genetic analyses, multi-omics network dissection, marker-assisted selection, genomic selection, and gene editing to elucidate the genetic mechanisms underlying chestnut processing quality and enable the precision breeding of processing-specific cultivars.

Horticulturae doi: 10.3390/horticulturae12091079

Authors: Yakun Zheng Daling Feng Shuxin Xuan Lisong Ma Shan Wang Mingrui Zhang Aixia Gu C. Robertson McClung Yanhua Wang Shuxing Shen

Shade avoidance response (SAR) is an important adaptive mechanism that enables plants to optimize light capture in dense canopies, but excessive shade-induced hypocotyl elongation can negatively affect plant architecture, yield, and quality in Chinese cabbage. In this study, we investigated the genetic basis of SAR using an advanced intercross recombinant inbred line (AI RIL) population derived from a cross between the oil type Chinese cabbage ‘R500’ with significantly longer hypocotyls and the vegetable type Chinese cabbage ‘L58’ with shorter hypocotyls. Quantitative trait locus (QTL) mapping under simulated shade, represented by a low red/far-red light ratio of 0.5, and non-shade conditions, represented by a high red/far-red light ratio of 2.0, identified several candidate genes associated with hypocotyl elongation, including COP1, XTH17, HYH and SRR1. Among these genes, BrSRR1 was selected for functional validation by introducing two alleles of BrSRR1 coding sequences into the Arabidopsis srr1 mutant. Under simulated shade, the srr1 mutant exhibited significantly longer hypocotyl than wild-type Col-0, whereas the BrSRR1-L58 restored hypocotyl length to a level statistically indistinguishable from that of wild-type Col-0. In contrast, the BrSRR1-R500 failed to complement the mutant phenotype, indicating ecotype-specific and allele-dependent functional divergence. Collectively, these findings indicate that BrSRR1 is implicated as a candidate gene involved in negative regulation of shade-induced hypocotyl elongation, though pending validation in the native species, providing insights into the genetic regulation of SAR in Chinese cabbage and a potential target for breeding varieties with reduced shade-induced hypocotyl elongation suited to high-density planting.

Horticulturae doi: 10.3390/horticulturae12091077

Authors: Xueli Li Fudong Huang Tao Zhang Fangai Shao Shengjuan Jiang

The mycelium of Phallus rubrovolvatus contains abundant metabolites with broad application prospects in functional foods and pharmaceuticals. However, how carbon and nitrogen substrate availability regulate the accumulation dynamics of mycelial metabolites remains under-explored. In this study, the supply levels of carbon (glucose) and nitrogen (peptone) were optimized to select high-biomass mycelia. Integrating nutritional activity assays with metabolomics and redundancy analysis, the regulatory mechanisms governing carbon–nitrogen metabolic flux were deciphered. The results demonstrated that mycelial nutritional content and antioxidant capacity exhibited a progressive upward trend under three distinct modes: carbon-driven, nitrogen-driven, and carbon–nitrogen synergistic-driven regimes. In the optimal carbon–nitrogen synergistic-driven group, the contents of total soluble sugars, reducing sugars, flavonoids, total phenolics, and soluble proteins increased by 72.06%, 160.80%, 52.47%, 113.69%, and 8.21%, respectively, compared with the control group. Meanwhile, the scavenging rates of superoxide anion, hydroxyl, ABTS, and DPPH free radicals increased by 14.12%, 24.09%, 14.77%, and 66.47%, respectively, compared with the control group. Differentially accumulated metabolites were significantly enriched in amino acid metabolism, energy metabolism, and secondary metabolite biosynthesis pathways. Carbon and nitrogen substrates reshaped intracellular metabolic flux, cooperatively regulating nutrient synthesis and intracellular redox equilibrium. This work reveals a cascade-linking relationship in which nutrient supply triggers metabolic remodeling, regulates oxidative balance, and drives pathway response. It provides theoretical support for the precision fermentation and industrial upgrade of P. rubrovolvatus, while offering a valuable reference paradigm for the high-value exploitation of other rare edible and medicinal fungi.

Horticulturae doi: 10.3390/horticulturae12091076

Authors: Ornprapa Thepsilvisut Sukunya Pengsawang Bhornchai Harakotr Preuk Chutimanukul Opas Trithaveesak Jutamas Romkaew

This study evaluated the effects of growing media and fertilizer applications on greenhouse strawberry cultivars ‘Pharachatan 80’ and ‘US Jumbo’ using a 4 × 3 factorial in CRD with five replications. Growing media comprised sand (S), coconut coir dust (C), and cow manure (M) in varying ratios (1:1, 1:1:1, 1:1:2, and 1:1:3 v/v), paired with no chemical fertilizer (NCF), a half-recommended dose (½ RDCF), or a full recommended dose of chemical fertilizer (RDCF). Results revealed that unamended substrate (S:C = 1:1 v/v) under NCF severely constrained crop performance. Conversely, integrating cow manure with chemical fertilizers significantly enhanced vegetative growth and yield attributes. Specifically, S:C:M 1:1:1 v/v combined with ½ RDCF optimized total marketable yield, increased the proportion of Grade 2–4 fruits, and improved fruit quality across both cultivars. However, elevated temperatures in tropical lowland greenhouses constrained fruit enlargement, resulting in ≥70% Low-Grade fruits (<7.0 g). Correlation and principal component analyses confirmed that balanced root-zone management mitigates severe nutrient stress. Overall, S:C:M 1:1:1 v/v with ½ RDCF represents the most effective strategy for tropical greenhouse strawberry cultivation, although implementing microclimate cooling or exogenous biostimulants remains necessary to overcome high-temperature limitations.

Horticulturae doi: 10.3390/horticulturae12091075

Authors: Dennis Baffour-Awuah Michael Batame Alexa J. Lamm Kevan W. Lamm Jeb Fields James Altland Guilherme Signorini

Peat is commonly used in container substrates; however, concerns about reliance on imported products, inconsistent availability, and environmental sustainability are increasing growers’ interest in transitioning to alternative soilless substrates. Several studies have explored growers’ perceptions of alternative material use in greenhouse and nursery settings, but less is known about how stakeholders in the horticultural industry evaluate the adoption of peat-alternative substrates. Therefore, this study used the five perceived innovation attributes of Diffusion of Innovations (DOI) theory to examine horticultural industry stakeholders’ considerations related to peat-alternative substrate adoption in the U.S. Three focus groups involving 35 horticultural industry stakeholders, including specialty crop growers, research scientists, crop consultants, and professionals in other horticultural industry roles, were conducted in Ohio and Florida. The focus group data were first analyzed inductively to identify themes, then analyzed deductively through DOI’s five perceived innovation attributes: relative advantage, compatibility, complexity, trialability, and observability. Findings indicated participants frequently discussed compatibility and complexity concerns, while relative advantage reflected considerations of substrate performance, economic viability, environmental sustainability, and supply reliability. Relative advantages were discussed predominantly positively, whereas complexity was discussed predominantly negatively. Trialability and observability were described as potentially reducing uncertainty through small-scale testing, demonstration trials, and observing others’ successful adoption. Overall, the findings suggest that economic feasibility, compatibility with existing production systems, and opportunities to observe and test peat alternatives were important considerations among participants and may inform future extension, applied research, and industry efforts related to peat-alternative substrate adoption.

Horticulturae doi: 10.3390/horticulturae12091074

Authors: Mónika Márkus Barnabás Kovács Balázs Madarász Levente Kardos Zsolt Kotroczó

Under changing environmental conditions, soil buffering capacity is a key soil-related component of terroir functional stability and vineyard resilience. We assessed the effects of sheep wool and alfalfa hay under-vine mulches during the first two years after treatment establishment in four vineyards with contrasting volcanic and loess-derived soil in the Tokaj Wine Region. Soil responses were evaluated using soil organic carbon (SOC), permanganate oxidizable carbon (POXC), fluorescein diacetate (FDA) hydrolytic activity, easily extractable glomalin-related soil protein (EE-GRSP), and the relationships of EE-GRSP with SOC and clay fraction. Mulch effects were site-specific rather than uniform. SOC values remained close to or above baseline levels in several vineyard–treatment combinations. POXC relative variability decreased in mulch-treated plots, with the proportion of highly variable units declining from 75% to 25% in both mulch treatments by autumn 2025, while this category remained dominant in the control. FDA activity was mainly associated with soil depth and vineyard-specific conditions. EE-GRSP showed positive relationships with both SOC and clay fraction. Neither mulch material showed consistent superiority across all indicators during the first two years. These findings suggest that soil buffering capacity was best interpreted as the outcome of multiple biological, organic matter-related, and mineral-associated processes operating at different temporal scales. Natural under-vine mulches may support soil stability, although longer-term monitoring is needed to assess the persistence of these responses.

Horticulturae doi: 10.3390/horticulturae12091071

Authors: Mario Njavro Tajana Čop Boris Duralija

In horticulture, a delayed shipment or failed food-safety check can rapidly cut off market access, yet strategic risk management remains weakly developed. This paper examines how artificial intelligence (AI), agritech, and business model innovation can reduce uncertainty and strengthen resilience across horticultural value chains. Using a structured conceptual review, it integrates six literature streams: agricultural risk, supply-chain risk management, strategic and enterprise risk management, farming-system resilience, digital innovation and AI, and business model innovation. The synthesis connects risk exposure to five digital functions (sensing, predicting, verifying, coordinating, and deciding) to dynamic capabilities, business model and governance conditions, and resilience outcomes. It develops five connected propositions concerning the conversion of information into action, credible digital verification, adoption conditions, market-access resilience, and business-model-enabled shared capability. Market-access resilience is introduced as the capacity to maintain or restore verified quality, food-safety assurance, traceability, compliance, and buyer relationships during disruption. The propositions are theoretically derived and empirically informed, providing a foundation for further empirical validation, particularly of the complete market-access and business model relationships. The findings imply that digital technologies contribute to resilience only when supported by coordinated action, sound data governance, human oversight, and viable, inclusive delivery models.

Horticulturae doi: 10.3390/horticulturae12091073

Authors: Jiale Cai Jun Sun Sunli Cong Xingyu Ji Jingyi Liu Yanjun Yu

Kiwifruit softens rapidly after harvest, and its marketable quality depends on firmness, soluble solids, dry matter, acidity, mechanical damage, disease, aroma and other attributes that determine grading, storage and sales. Traditional physicochemical tests are accurate but usually destructive, time-consuming and unsuitable for batch sorting, online monitoring or dynamic quality management. This review summarizes six non-destructive testing approaches: optical, acoustic, electromagnetic, dielectric, mechanical/texture-property and electronic nose technologies. Their principles, system configurations, quality indicators, modeling strategies, applications and limitations are compared, with particular attention to validation design, model transferability, approximate technology maturity and industrial constraints. Current evidence shows that near-infrared spectroscopy and hyperspectral imaging are most widely used for soluble solids, firmness, dry matter, chilling injury and early damage detection; machine vision is effective for appearance grading and surface defects; acoustic and mechanical methods mainly support firmness and texture evaluation; dielectric and electromagnetic techniques help characterize moisture, tissue structure and internal disorders; and electronic noses capture volatile signals related to ripening and spoilage. Future work should prioritize cross-variety, cross-origin and cross-device model transfer, multi-source sensor fusion, interpretable modeling, portable instruments, online deployment and standardized validation.

Horticulturae doi: 10.3390/horticulturae12091072

Authors: Bingru Wang Yingyao He Zexuan Li Wenwen Yu Xiumei Dai Jiankui Zhang Kexuan Deng

Phytophthora parasitica is a devastating oomycete pathogen that causes significant crop losses worldwide. Identifying master regulators of its virulence is crucial for the development of novel control strategies. Here, we demonstrate that the conserved eukaryotic kinase TOR (target of rapamycin) is essential for both growth and pathogenicity in P. parasitica. Transcriptomic analysis revealed that PpTOR inhibition broadly reprograms the transcriptome of P. parasitica, notably leading to the downregulation of numerous PpRxLR and PpCRN effector genes. Among these genes, the overexpression of PpRxLR3 increased plant susceptibility to P. parasitica by affecting jasmonic acid biosynthesis and signaling. On the basis of the crucial role of PpTOR, we evaluated its potential as a target for intervention. Host-induced gene silencing (HIGS) of PpTOR in Nicotiana benthamiana conferred strong resistance to P. parasitica, which was associated with the downregulation of the expression of PpTOR and key effector genes during P. parasitica infection. Furthermore, small RNA sequencing confirmed the production of PpTOR-specific siRNAs in HIGS plants. Exogenous application of synthetic siRNAs targeting PpTOR effectively reduced P. parasitica virulence. Our findings establish PpTOR as a global regulator of pathogenicity and validate PpTOR as a promising target for RNA-based disease control strategies.

Horticulturae doi: 10.3390/horticulturae12091070

Authors: Yue Li Zhouyu Yu Jiaxin Xu Jianshe Li Xia Zhao Kai Cao Jianbing Feng Rui Ma Lin Ye

Continuous cropping obstacles severely constrain Chinese chive (Allium tuberosum) production, yet the integrated mechanisms involving soil properties, microbial communities, and rhizosphere metabolites remain unclear. We hypothesized that long-term monoculture induces soil degradation and shifts rhizosphere microbiomes via accumulated putative allelochemicals, with a critical tipping point. Rhizosphere soils from 1-to-5-year continuous cropping fields were analyzed using high-throughput sequencing, non-targeted metabolomics, and physicochemical assays. Results showed significant salinization and nutrient depletion after three years, along with a slight decrease in soil pH. Enzyme activities (sucrase, urease, alkaline phosphatase, and catalase) first rose then fell. Bacterial richness declined sharply after four years, with beneficial genera (such as Devosia) decreasing and pathogenic genera (such as Thelonectria) enriched. Metabolomics identified 1175 metabolites, primarily enriched in linoleic acid and α-linolenic acid pathways. Oxidized fatty acids accumulated significantly and correlated positively with pathogen abundance and negatively with beneficial bacteria. We conclude that continuous chive cropping exceeding three years is associated with soil degradation via putative allelochemical accumulation and pathogen enrichment. We recommend crop rotation after three years, offering a theoretical basis for sustainable chive production.

Horticulturae doi: 10.3390/horticulturae12091069

Authors: Min Zhang Dian Shen Hechi Li Jing Wu Yuanlin Sun Peiqian Li Baozhen Feng

Microbe-derived elicitors can trigger plant immune responses, but elicitors from endophytic Bacillus species remain largely unexplored. Based on preliminary findings that endophytic Bacillus subtilis K1 can elicit grape immune responses, this study aimed to investigate the elicitor proteins produced by K1 and the effect on the control of gray mold in grapes. A novel elicitor protein PeBs1 screened from the genome of K1 could induce a strong hypersensitive response in Nicotiana benthamiana by Agrobacterium-mediated transformation, accompanied by significant reactive oxygen species accumulation and callose deposition. The PeBs1 gene encodes a 15.9 kDa protein consisting of 181 amino acids, which is evolutionarily conserved within the genus Bacillus. Exogenous infiltration with 10 μM purified PeBs1 protein also triggered typical hypersensitive response symptoms in N. benthamiana. Application of the purified PeBs1 to grape berries significantly reduced the incidence of gray mold and boosted the activities of defense enzymes, including peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT), and phenylalanine ammonia-lyase (PAL), while also lowering the malondialdehyde (MDA) content. Meanwhile, PeBs1 treatment markedly increased the contents of total phenols and total flavonoids in grape berries, and significantly up-regulated the transcriptional levels of defense-related genes (VvPAL, VvPPO, VvPR1, VvPR2). This study suggests that PeBs1 from endophytic Bacillus may act as an immune activator to enhance grape resistance against gray mold. The findings provide a basis for exploring potential strategies to manage grape postharvest diseases.

Horticulturae doi: 10.3390/horticulturae12091068

Authors: Seong Ju Lee Tae Seon Eom Tae Wan Kim Sung Yung Yoo

Chlorophyll fluorescence provides sensitive information on plant photochemical responses, but its measurement requirements can limit high-throughput application. This study investigated whether RGB imagery could approximate chlorophyll-fluorescence-derived photochemical status across garden plant species during progressive soil drying. A Photochemical Status Index (PSI) was constructed by principal component analysis from five highly correlated JIP-test energy-flux variables (RC/CS, ABS/CS, TRo/CS, ET2o/CS, and RE1o/CS). The dataset comprised 50 aggregated species-by-soil-moisture-stage observations representing ten species and five sequential soil-moisture stages. Eleven RGB-derived variables were evaluated, and a partial least-squares regression model was assessed using nested leave-one-species-out validation, with all data-dependent procedures repeated within each outer training fold. PC1 explained 96.5% of the shared variation among the fluorescence-derived fluxes. The predictors g, GLI, ExG, ExGR, and CIVE were retained in all ten outer folds. The final model yielded a pooled out-of-fold R2 of 0.469, an RMSE of 1.585, and an MAE of 1.183. However, species-specific R2 ranged from −0.179 to 0.959, and a calibration slope of 0.509 indicated prediction-range compression. These findings provide proof-of-concept evidence of moderate RGB-based approximation of fluorescence-derived photochemical status, but inconsistent species transferability and the common soil-moisture/time gradient require external validation before practical deployment.

Horticulturae doi: 10.3390/horticulturae12091067

Authors: Siru Pu Leilei Deng Qi Hou Zhigang Zhang Qian Zhang Guangyi Liu

Addressing technical challenges such as inaccurate appearance detection, inaccurate weight estimation, and low automation levels in passion fruit sorting under postharvest conveyor-line conditions, this study proposes an intelligent detection and grading model, YOLOv11n-ACH, based on an improved YOLOv11n. By integrating the Hybrid Inverted Block (HIB) module, the ASF-YOLO scale fusion mechanism, and the Convolutional Attention Fusion Mechanism (CAFM), the model effectively mitigates severe fruit occlusion and background interference caused by conveyor surfaces, residual plant material, and illumination variation. Consequently, the high-precision metric mAP@50-95 reaches 99.4%, representing an increase of 3.9 percentage points over the baseline model. Building upon this foundation, a real-time grading and counting system incorporating a confidence-priority frame-selection mechanism was constructed by combining the ByteTrack multi-object tracking algorithm with horizontal dynamic scale calibration technology. The study establishes a multivariate linear regression mass-estimation model based on morphological features (R2 = 0.9617). The regression model was developed using 500 fruits, and its performance was independently evaluated using a second, non-overlapping cohort of 500 fruits collected from the same orchard. Using 12 horizontal calibration points, a cubic spline interpolation function was constructed to compensate for horizontal position-dependent variation in the pixel-to-physical scale under the tested fixed imaging configuration. In the independent mass-validation cohort, the system achieved an MAE of 2.54 g, an RMSE of 3.21 g, and an MARE of 5.65%. A third, non-overlapping cohort of 1568 fruits was used for end-to-end passage-level counting and operational grading evaluation. This lightweight solution provides an engineering approach for passion-fruit sorting under the tested postharvest conveyor-line conditions.

Horticulturae doi: 10.3390/horticulturae12091066

Authors: Rachel Stone Sisi Chen Pamela Moon Jianjun Chen Xingbo Wu

Vanilla planifolia, the principal source of natural vanilla flavor, is an economically important aromatic and medicinal crop. Its genetic improvement is constrained by a narrow cultivated genetic base, extensive clonal propagation, the long juvenile period before plants reach reproductive maturity, and limited cytogenetic information for wild relatives and interspecific hybrids. This study estimated 2C nuclear DNA content in 91 Vanilla accessions maintained at the University of Florida Tropical Research and Education Center, including 56 V. planifolia accessions, 21 accessions representing nine additional taxa, and 14 recorded interspecific hybrids. Young apical node tissue was co-chopped with Oryza sativa ssp. japonica ‘Nipponbare’ (2C = 0.795 pg), stained with propidium iodide, and analyzed by flow cytometry. Vanilla planifolia ranged from 3.32 to 4.13 pg 2C (3.25–4.04 Gbp equivalents), with a mean of 3.78 pg 2C (3.52 Gbp). Among the other taxa, V. phaeantha averaged 3.60 pg 2C (3.52 Gbp), whereas V. barbellata averaged 6.30 pg 2C (6.16 Gbp). The eight V. pompona accessions ranged from 5.74 to 6.19 pg 2C (5.61–6.05 Gpb). Recorded interspecific hybrids ranged from 3.57 to 7.36 pg 2C (3.49–7.20 Gbp). Several hybrid-designated accessions fell outside simple expectations based on the observed parental-species ranges, but flow cytometry alone cannot distinguish ploidy, aneuploidy, parentage, or peak-assignment effects associated with endoreplication. These data provide a comparative baseline for germplasm curation and identify accessions that warrant chromosome counting, molecular identification, parentage verification, and reproductive evaluation before breeding interpretation.

Horticulturae doi: 10.3390/horticulturae12091065

Authors: Zhong Peng Xueping Guo Anqi Wen Shiqiang Liu Yong Zhou Zhaoyang Hu Yuelong Zhou

Plant Unconventional Prefoldin RPB5 Interactor (URI) proteins are key functional factors regulating plant growth, development, and stress responses, playing important roles in root morphogenesis, gravitropism regulation, and environmental stress signaling pathways. To investigate the biological function of the pepper URI gene, we identified the pepper URI homolog (CaURI) through sequence alignment and performed functional characterization using multiple molecular approaches. The pepper URI gene successfully rescued the shortened root length and impaired the root gravitropism phenotypes of the Arabidopsis uri-1 mutant. Subcellular localization revealed that the pepper URI protein was localized in the cytoplasm. Overexpression of pepper URI in Arabidopsis significantly inhibited root and hypocotyl elongation. RNA-seq analysis revealed that the expression patterns of many genes involved in growth and development were significantly altered in the CaURI-overexpressing Arabidopsis. Silencing of the endogenous pepper URI gene led to a marked reduction in plant height, and this dwarf phenotype was further aggravated under heat stress conditions. This work enriches the functional framework of the plant URI gene family and provides valuable genetic resources and a theoretical basis for dissecting the molecular mechanisms underlying pepper growth regulation and heat tolerance.