Horticulturae

Article

15 pages, 1566 KiB

Open AccessEditor’s ChoiceArticle

Biostimulants Improve Bulb Yield, Concomitantly Affecting the Total Phenolics, Flavonoids, and Antioxidant Capacity of Onion (Allium cepa)

by Đorđe Vojnović, Ivana Maksimović, Aleksandra Tepić Horecki, Anita Milić, Zdravko Šumić, Danijela Žunić, Boris Adamović and Žarko Ilin

Horticulturae 2024, 10(4), 391; https://doi.org/10.3390/horticulturae10040391 - 11 Apr 2024

Viewed by 944

Abstract

In the pursuit of maximizing onion (Allium cepa) yield and quality, farmers often face the challenges of unfavorable ecological conditions and inadequate agronomic practices. Therefore, our two-year study investigated the effects of biostimulants (BTs) of plant growth on bulb yield and [...] Read more.

In the pursuit of maximizing onion (Allium cepa) yield and quality, farmers often face the challenges of unfavorable ecological conditions and inadequate agronomic practices. Therefore, our two-year study investigated the effects of biostimulants (BTs) of plant growth on bulb yield and the bioactive compounds of directly seeded onion. Four treatments were applied: control (C), seaweed extracts (BT1), humic and fulvic acid (BT2), and Trichoderma spp. (BT3). The results demonstrated a significant increase in bulb yield with BT1 (↑ 18.7%), BT2 (↑ 18.0%), and BT3 (↑ 24.3%). Intriguingly, all BTs markedly reduced phenolic content across both years. Additionally, BT1 and BT3 elevated flavonoid levels (↑ 16.8% and ↑ 16.7%, respectively), while BT2 decreased them (↓ 24.2%). Notably, in 2021, DPPH, FRAP, and ABTS tests indicated a significant reduction in antioxidant capacity compared to C. Our study underscores the important role of BTs in enhancing yield, influencing secondary metabolites and contributing to environmental sustainability in onion cultivation. Full article

(This article belongs to the Special Issue The Role of Biostimulants in Horticultural Crops)

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27 pages, 17664 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Xylem Hydraulic Conductance Role in Kiwifruit Decline Syndrome Occurrence

by Claudio Mandalà, Stefano Monaco, Luca Nari, Chiara Morone, Francesco Palazzi, Grazia Federica Bencresciuto and Laura Bardi

Horticulturae 2024, 10(4), 392; https://doi.org/10.3390/horticulturae10040392 - 11 Apr 2024

Viewed by 1209

Abstract

Kiwifruit decline syndrome (KiDS) has affected kiwifruit orchards for more than ten years in the Mediterranean area, severely compromising productivity and causing extensive uprooting. The affected plants go through an irreversible and fast wilting process. The problem has not been solved yet, and [...] Read more.

Kiwifruit decline syndrome (KiDS) has affected kiwifruit orchards for more than ten years in the Mediterranean area, severely compromising productivity and causing extensive uprooting. The affected plants go through an irreversible and fast wilting process. The problem has not been solved yet, and a single cause has not been identified. In this work, we carried out a survey on ten five-year-old healthy kiwifruit cv. Hayward plants cultivated in an area strongly affected by KiDS and characterised by a rising temperature and vapor pressure deficit (VPD). Five plants were located in a KiDS-affected orchard. Our goal was to assess the hydraulic conductance of asymptomatic plants in a KiDS-affected area where rising climate change stress is underway. Our hypothesis was that a rising temperature and VPD could impair xylem functionality, leading the plants to develop strategies of tolerance, such as vessel narrowing, or stress symptoms, such as cavitation or implosion, inducing a higher risk of KiDS onset. Hydraulic conductance was investigated using a physiological and morphological approach to detect trunk sap flow, trunk growth and daily diameter variations, leaf gas exchanges and temperature, stem water potential, and the root xylem vessel diameter and vulnerability to cavitation. A strong xylem vessel narrowing was observed in all plants, with the highest frequency in the 30–45 µm diameter class, which is an indicator of long-term adaptation to a rising VPD. In some plants, cavitation and implosion were also observed, which are indicative of a short-term stress response; this behaviour was detected in the plants in the KiDS-affected orchard, where a high leaf temperature (>39 °C), low stomatal conductance (<0.20 mol H₂O m⁻² s⁻¹) and transpiration (<3 mmol H₂O m⁻² s⁻¹), low stem water potential (<−1 MPa), high vulnerability to cavitation (3.7 μm mm⁻²), low trunk sap flow and high daily stem diameter variation confirmed the water stress status. The concurrence of climate stress and agronomic management in predisposing conditions favourable to KiDS onset are discussed, evidencing the role of soil preparation, propagation material and previous crop. Full article

(This article belongs to the Special Issue Investigation of Environmental Stress Tolerance and Physiology in Horticultural Crops)

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15 pages, 4243 KiB

Open AccessEditor’s ChoiceArticle

A Genome-Wide Analysis of the WUSCHEL-Related Homeobox Transcription Factor Family Reveals Its Differential Expression Patterns, Response to Drought Stress, and Localization in Sweet Cherry (Prunus avium L.)

by Fei Deng, Hongming Wang, Xiaojuan An and Jean Yves Uwamungu

Horticulturae 2024, 10(4), 370; https://doi.org/10.3390/horticulturae10040370 - 7 Apr 2024

Viewed by 1151

Abstract

The WUSCHEL-related homeobox (WOX) gene family has a critical effect on plant development and abiotic stress. However, there have been no genome-wide studies on WOX genes within sweet cherry (Prunus avium L.). In the present work, eight PavWOX genes were [...] Read more.

The WUSCHEL-related homeobox (WOX) gene family has a critical effect on plant development and abiotic stress. However, there have been no genome-wide studies on WOX genes within sweet cherry (Prunus avium L.). In the present work, eight PavWOX genes were discovered within sweet cherry at the genome-wide level, and they were mapped to six chromosomes. Based on phylogenetic relationships, these genes were classified into three groups, with genes in one group having similar gene structures and conserved motifs. Meanwhile, the PavWOX genes possessed cis-acting elements and functions associated with hormone responses, stress responses, and development. As revealed by expression patterns, certain PavWOX genes are specifically expressed within tissues, suggesting that they may have unique functions. Additionally, the gene family expression patterns under drought stress were analyzed. PavWOX4, PavWOX5, PavWOX13A, and PavWOX13B had increased expressions upon drought stress. In addition, the transcription factor of PavWOX4 and PavWOX13A was localized in the nucleus, confirming the estimated results. Our findings lay the foundation for determining the expression patterns and functions of the PavWOX gene family within sweet cherry and shed more light on the underlying regulatory mechanisms. Full article

(This article belongs to the Collection New Insights into Developmental Biology of Fruit Trees)

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23 pages, 10810 KiB

Open AccessEditor’s ChoiceArticle

Selection of Spectral Parameters and Optimization of Estimation Models for Soil Total Nitrogen Content during Fertilization Period in Apple Orchards

by Zhilin Gao, Wenqian Wang, Hongjia Wang and Ruiyan Li

Horticulturae 2024, 10(4), 358; https://doi.org/10.3390/horticulturae10040358 - 4 Apr 2024

Viewed by 837

Abstract

The rapid and accurate diagnosis of nitrogen content in apple orchard soil is of great significance for the rational application of nitrogen fertilizer in orchards to improve apple yield and quality. An apple orchard in Shuangquan Town, Changqing District, Jinan City, Shandong Province, [...] Read more.

The rapid and accurate diagnosis of nitrogen content in apple orchard soil is of great significance for the rational application of nitrogen fertilizer in orchards to improve apple yield and quality. An apple orchard in Shuangquan Town, Changqing District, Jinan City, Shandong Province, was taken as the experimental area. The optimal method for extracting spectral characteristic bands and screening spectral characteristic indices (SCIs) of soil total nitrogen (TN) for independent and comprehensive fertilization periods was explored. Independent and comprehensive soil TN content estimation models were constructed and optimized for each and the entire fertilization period, respectively. The results show that compared with the correlation coefficient method, stepwise multiple linear regression (SMLR) performs better in extracting hyperspectral characteristic bands of soil TN content. It helps to achieve a higher modeling accuracy, smaller root mean square error (RMSE), and is more conducive to avoiding the influence of multicollinearity of model variables. The sensitive areas of soil TN content in the SCI do not undergo significant changes due to different fertilization periods. Among them, the ratio spectral indices (RSIs) are in the range of 800–900 nm, 1900–1950 nm, and 2200–2300 nm, while the sensitive areas of the difference spectral index (DI) and Normalized difference spectral index (NDSI) are in the range of 1900–1950 nm and 2200–2300 nm. The combination of SCI and characteristic bands significantly improves the prediction accuracy of soil TN estimation models. The independent and comprehensive estimation models for each fertilization period based on the BP (back propagation) neural network optimized by the Mind Evolution Algorithm (MEA-BPNN) can achieve a more stable and accurate estimation of soil TN. Finally, using soil spectral characteristic bands selected through continuum removal (CR) transformation and SMLR, combined with SCI, the model based on the MEA-BPNN (CR-SCI-MEA-BPNN) has the best prediction performance. The modeling determination coefficients R² for each fertilization period reached 0.94, 0.95, 0.92, and 0.94, respectively, with RMSE of 0.0032, 0.0024, 0.0035, and 0.0027. The R² and RMSE of the modeling and validation set of the entire fertilization period comprehensive model are 0.899, 0.0038, and 0.89, 0.0041, respectively. The results of this article provide technical support for promoting the timely monitoring of soil TN content and guiding rational fertilization in apple orchards. Full article

(This article belongs to the Special Issue Application of Remote Sensing Technology in Orchard Precision Management)

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15 pages, 1549 KiB

Open AccessEditor’s ChoiceArticle

Phenological Evaluation of Minority Grape Varieties in the Wine Region of Madrid as a Strategy for Adaptation to Climate Change

by Francisco Emmanuel Espinosa-Roldán, Andrés García-Díaz, Eva Raboso, Julia Crespo, Félix Cabello, Fernando Martínez de Toda and Gregorio Muñoz-Organero

Horticulturae 2024, 10(4), 353; https://doi.org/10.3390/horticulturae10040353 - 3 Apr 2024

Viewed by 848

Abstract

In this study, a total of 34 Spanish minority varieties were studied during four seasons from 2020 to 2023, and their behavior was characterized according to their main phenological stages (bud break, bloom, veraison, and maturity) and complete cycle. We focused on the [...] Read more.

In this study, a total of 34 Spanish minority varieties were studied during four seasons from 2020 to 2023, and their behavior was characterized according to their main phenological stages (bud break, bloom, veraison, and maturity) and complete cycle. We focused on the varieties prospected in the central Spanish plateau and conserved in the “El Encín” grapevine collection, aiming to identify the potential for adaptation of these varieties and for them to be considered by winegrowers as an alternative to current climate change conditions. The growing degree days required for the expression of the phenological stage, and the duration of each stage, were compiled. Characteristics of oenological interest were also monitored, such as °Brix, pH, and titratable acidity in must at the time of harvest. This study was carried out in years with atypical snowfall and cold spells (winter 2021), as well as with heat waves (summer 2022), with average temperatures 3–5 °C higher than normal and absolute maximum temperatures over 40 °C. Both cases also exceeded records of historical series (1957–2019). Veraison has been identified as the stage most susceptible to damage from high temperatures, in addition to the maturation and duration of the complete cycle. The varieties were classified into five groups according to the duration of each phenological stage (very early, early, medium, late, and very late). Some varieties with late or very late maturation and with must characteristics of 20–23 °Brix, 3–5 g/L of titratable acidity, and pH 3.5–4.5, as well as others, retained stability in their phenological periodicity and must quality. The results suggest that special attention should be given to thoroughly evaluating these varieties, and that the strategies contemplated should be considered as a feasible cultivation alternative in viticulture to mitigate the effects of climate change. Full article

(This article belongs to the Special Issue Vine Cultivation in an Increasingly Warming World)

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14 pages, 2133 KiB

Open AccessEditor’s ChoiceArticle

Effect of Different LED Light Wavelengths on Production and Quality of Pleurotus ostreatus Grown on Different Commercial Substrates

by Marina De Bonis, Silvia Locatelli, Paolo Sambo, Giampaolo Zanin, John A. Pecchia and Carlo Nicoletto

Horticulturae 2024, 10(4), 349; https://doi.org/10.3390/horticulturae10040349 - 31 Mar 2024

Cited by 1 | Viewed by 1605

Abstract

Artificial lighting, primarily employed in crop production, can also be applied to the cultivation of edible mushrooms to enhance productivity and quality. While UV radiation has predominantly been investigated in post-harvest treatments for edible mushrooms, the utilization of different light wavelengths during the [...] Read more.

Artificial lighting, primarily employed in crop production, can also be applied to the cultivation of edible mushrooms to enhance productivity and quality. While UV radiation has predominantly been investigated in post-harvest treatments for edible mushrooms, the utilization of different light wavelengths during the cultivation phase remains largely unexplored for many mushroom species. This study aimed to assess the impact of three different light wavelengths 450 nm (B), 610 nm (R), and a combination of these two wavelengths (R + B) on the productive characteristics and quality of Pleurotus ostreatus, cultivated using three straw-based commercial substrates. It was observed that, except for yield, artificial light influenced mushroom growth. Specifically, the application of R light appeared to promote mycelium growth, whereas B light contributed to increase the diameter of fruiting bodies. Additionally, the concentration of vitamin D₂ was higher under both B and R+B light treatments. Interestingly, the light treatments did not affect yield but impacted diameter and various chemical attributes such as EC, total soluble solids, and titratable acidity. In conclusion, exposure to different lighting affected Pleurotus ostreatus physiology and nutritional content. Full article

(This article belongs to the Section Vegetable Production Systems)

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13 pages, 4958 KiB

Open AccessEditor’s ChoiceArticle

‘Juxiangyuan’ Seedless Orange: A New Mutant with Male and Female Sterility

by Feng Zhang, Qinggang Wang, Jianming Luo, Alessandra Gentile, Guiyou Long, Ziniu Deng, Dazhi Li and Na Li

Horticulturae 2024, 10(4), 350; https://doi.org/10.3390/horticulturae10040350 - 31 Mar 2024

Viewed by 1055

Abstract

Seedless is a highly valued commercial characteristic in the citrus industry, both for fresh consumption and for processed markets. In this study, the ‘Succari Sweet Orange’ (WT) and its seedless mutant ‘Juxiangyuan’ (MT), which originated from a bud mutation, were selected to study [...] Read more.

Seedless is a highly valued commercial characteristic in the citrus industry, both for fresh consumption and for processed markets. In this study, the ‘Succari Sweet Orange’ (WT) and its seedless mutant ‘Juxiangyuan’ (MT), which originated from a bud mutation, were selected to study the formation of a citrus seedless phenotype. Microscopic analysis of MT’s floral organs, including anther and ovary cross-sections, provides insights into its seedless phenotype compared to the original seeded cultivar. Additionally, pollen features, viability, and in vitro germination were examined to determine the cause of seedlessness. MT exhibited significant developmental deformities in both male and female gametes, with pollen grain analysis indicating a high rate of deformity (41.48%), low viability (9.59%), and minimal in vitro germination (9.56%). Hybridization experiments were conducted to assess male and female sterility and pollen incompatibility. Both WT and MT exhibited parthenocarpic development. Notably, MT fruit produced with an average of 3.51 seeds pollinated to WT, despite severe pollen abortion of MT. MT, however, produced seedless fruit through self-breeding or cross-breeding with other varieties, demonstrating stable female sterility. Despite reduced pollen quantity and viability in the seedless mutant ‘Juxiangyuan’, its seedlessness primarily stems from female sterility. This study contributed to a deeper understanding of seedless formation in ‘Juxiangyuan’ and provided valuable information relevant to its commercial cultivation. Full article

(This article belongs to the Section Propagation and Seeds)

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16 pages, 5943 KiB

Open AccessEditor’s ChoiceArticle

Mycorrhizal Symbiosis Enhances P Uptake and Indole-3-Acetic Acid Accumulation to Improve Root Morphology in Different Citrus Genotypes

by Chun-Yan Liu, Xiao-Niu Guo, Feng-Jun Dai and Qiang-Sheng Wu

Horticulturae 2024, 10(4), 339; https://doi.org/10.3390/horticulturae10040339 - 29 Mar 2024

Cited by 1 | Viewed by 2987

Abstract

Arbuscular mycorrhizal fungi (AMF) are known to enhance plant growth via stimulation of root system development. However, the extent of their effects and underlying mechanisms across different citrus genotypes remain to be fully elucidated. This study investigates the impact of Funneliformis mosseae ( [...] Read more.

Arbuscular mycorrhizal fungi (AMF) are known to enhance plant growth via stimulation of root system development. However, the extent of their effects and underlying mechanisms across different citrus genotypes remain to be fully elucidated. This study investigates the impact of Funneliformis mosseae (F. mosseae) inoculation on plant growth performance, root morphology, phosphorus (P), and indole-3-acetic acid (IAA) concentrations, as well as the expression of related synthesis and transporter genes in three citrus genotypes: red tangerine (Citrus tangerine ex. Tanaka), kumquat (Fortunella margarita L. Swingle), and fragrant citrus (Citrus junos Sieb. ex. Tanaka). Following 12 weeks of inoculation, significant improvements were observed in plant height, shoot and root biomass, total root length, average root diameter, second-order lateral root development, root hair density, and root hair length across all genotypes. Additionally, F. mosseae inoculation significantly increased root P and IAA concentrations in the three citrus genotypes. Notably, phosphatase activity was enhanced in F. margarita but reduced in C. tangerine and C. junos following inoculation. Gene expression analysis revealed a universal upregulation of the P transporter gene PT5, whereas expressions of the auxin synthesis gene YUC2, transporter gene LAX2, and phosphatase gene PAP1 were commonly downregulated. Specific to genotypes, expressions of YUC5, LAX5, PIN2, PIN3, PIN6, and expansin genes EXPA2 and EXPA4 were significantly upregulated in C. tangerine but downregulated in F. margarita and C. junos. Principal component analysis and correlation assessments highlighted a strong positive association between P concentration, P and auxin synthesis, and transporter gene expressions with most root morphology traits, except for root average diameter. Conversely, IAA content and phosphatase activities were negatively correlated with these root traits. These findings suggest that F. mosseae colonization notably enhances plant growth and root system architecture in citrus genotypes via modifications in P transport and IAA accumulation, indicating a complex interplay between mycorrhizal symbiosis and host plant physiology. Full article

(This article belongs to the Special Issue Citrus Plant Growth and Fruit Quality)

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14 pages, 2812 KiB

Open AccessEditor’s ChoiceArticle

Detection of Hardening in Mangosteens Using near-Infrared Hyperspectral Imaging

by Saranya Workhwa, Thitirat Khanthong, Napatsorn Manmak, Anthony Keith Thompson and Sontisuk Teerachaichayut

Horticulturae 2024, 10(4), 345; https://doi.org/10.3390/horticulturae10040345 - 29 Mar 2024

Viewed by 921

Abstract

Mangosteens can develop a postharvest physiological disorder, called “hardening”, which affects their marketability and is not detectable using visual inspection. The hardening disorder of mangosteens was determined by firmness value using the texture analyzer. Near-infrared hyperspectral imaging (NIR-HSI) in the region of 935–1720 [...] Read more.

Mangosteens can develop a postharvest physiological disorder, called “hardening”, which affects their marketability and is not detectable using visual inspection. The hardening disorder of mangosteens was determined by firmness value using the texture analyzer. Near-infrared hyperspectral imaging (NIR-HSI) in the region of 935–1720 nm was tested as a possible rapid and non-destructive method to detect this disorder. The spectra from a region of interest of mangosteens were acquired and used for analysis. Calibration models for firmness of a similarly sized group and a mixed-size group were established using partial least squares regression (PLSR) and support vector machine regression (SVMR). Chemometric algorithms were investigated in order to determine the optimal conditions for establishing the models for firmness. The optimum model was obtained when the fruit were graded into similarly sized groups. Using partial least squares regression (PLSR), the correlation coefficient of prediction (R_p) was 0.87 and the root mean square error of prediction (RMSEP) was 6.25 N. The predictive images for firmness of the fruit were created by interpreting predicted firmness visualized as colors in every pixel. From the data, it was concluded that NIR-HSI can potentially be used to visualize hardening of individual mangosteens based on their predictive images. Full article

(This article belongs to the Section Postharvest Biology, Quality, Safety, and Technology)

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12 pages, 4034 KiB

Open AccessEditor’s ChoiceArticle

Near-Freezing Temperature Storage Improves Peach Fruit Chilling Tolerance by Regulating the Antioxidant and Proline Metabolism

by Handong Zhao, Shuqi Meng, Maorun Fu and Qingmin Chen

Horticulturae 2024, 10(4), 337; https://doi.org/10.3390/horticulturae10040337 - 28 Mar 2024

Viewed by 852

Abstract

Chilling injury (CI) in peach fruit (Prunus persica cv. Yuhualu) is generally caused by long-time low temperature (5 °C or 0 °C) storage. However, peach fruit stored at near-freezing temperature (NFT in this research is −1 °C), defined as within 0.5 °C [...] Read more.

Chilling injury (CI) in peach fruit (Prunus persica cv. Yuhualu) is generally caused by long-time low temperature (5 °C or 0 °C) storage. However, peach fruit stored at near-freezing temperature (NFT in this research is −1 °C), defined as within 0.5 °C above the biological freezing point of biological tissue, does not exhibit CI symptoms. The effect of NFT on the CI, proline metabolism, and antioxidant capability of peach fruit during storage was studied and compared with 5 °C and 0 °C storage as controls. The results exhibit that NFT completely inhibited the occurrence of CI in peach fruit. NFT significantly (p < 0.05) enhanced the activities of superoxide dismutase, catalase, ascorbate peroxidase, and 1,1-diphenyl-2-picrylhydrazyl scavenging capacity. Moreover, the increase of malondialdehyde, ion leakage, and H₂O₂ accumulation were inhibited remarkably by NFT, and decreases in the contents of phenolics and ascorbic acid were slowed significantly in peach fruit stored at NFT (p < 0.05). Additionally, NFT storage enhanced proline accumulation by modulating the activity of proline metabolizing enzymes. In conclusion, the above results suggest that NFT storage can improve the chilling tolerance of peach fruit by regulating the antioxidant defense and proline metabolism, which might represent a potential novel method to store fruits and vegetables for longer storage times. Full article

(This article belongs to the Special Issue Advanced Studies in Maintaining Post-harvest Quality of Fruits and Vegetables)

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25 pages, 5983 KiB

Open AccessEditor’s ChoiceArticle

Genome-Wide Identification and Expression Analysis of Fifteen Gene Families Involved in Anthocyanin Synthesis in Pear

by Lingchao Zhang, Bobo Song, Bo Li, Shiqiang Zhang, Yueyuan Liu, Guosong Chen, Jianhui Zhang, Jiaming Li and Jun Wu

Horticulturae 2024, 10(4), 335; https://doi.org/10.3390/horticulturae10040335 - 28 Mar 2024

Viewed by 1193

Abstract

Anthocyanins play a crucial role in imparting red coloration to pear fruits. However, the specific number and expression patterns of each member within the anthocyanin biosynthesis-related gene families in pears require systematic exploration. In this study, based on the pear genome we identified [...] Read more.

Anthocyanins play a crucial role in imparting red coloration to pear fruits. However, the specific number and expression patterns of each member within the anthocyanin biosynthesis-related gene families in pears require systematic exploration. In this study, based on the pear genome we identified 15 gene families involved in the anthocyanin biosynthesis pathway using the BLASTP and Hidden Markov Model search methods, comprising a total of 94 enzyme genes. Through phylogenetic analysis, conserved domains, motif, and gene structure analysis, these gene families were further categorized into eight distinct lineages. Subsequent collinearity analysis revealed that the expansion of anthocyanin synthesis-related gene families primarily originated from segmental duplications. Analysis of cis-element in the promoter regions of genes related to anthocyanin synthesis unveiled the presence of light-responsive elements and various hormone-responsive elements. This suggests that changes in light stimulation and hormone levels may influence anthocyanin synthesis. RNA-Seq and qRT-PCR analyses indicated differential expression of anthocyanin biosynthesis-related genes between the peel and flesh tissues. During the accumulation of anthocyanins in red-fleshed pears, upstream genes in the anthocyanin biosynthesis pathway such as PbrPAL2, PbrC4H2, PbrC4H3, Pbr4CL2, Pbr4CL17, PbrF3H5, and PbrF3H6 exhibited high expression levels, likely contributing significantly to the red coloration of pear flesh. In summary, we have identified the number of gene family members involved in pear anthocyanin biosynthesis and analyzed the expression patterns of the genes related to pear anthocyanin biosynthesis. These findings provide a solid foundation for further research on the regulatory mechanisms underlying pear anthocyanin biosynthesis and the breeding of red pear varieties. Full article

(This article belongs to the Special Issue Advanced Studies in Cultivation and Breeding of Pome Fruit Trees, Apples and Pears)

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15 pages, 3270 KiB

Open AccessEditor’s ChoiceArticle

Multi-Walled Carbon Nanotubes Improve the Development of Chrysanthemum × morifolium (Ramat.) Hemsl. ‘Jinba’ Inflorescences

by Yanbing Li, Yushan Lu, Jiaojiao Fu, Benxue Chen, Li Fu, Xiaorong Huang, Zunzheng Wei, Yuhong Zheng and Zhen Zeng

Horticulturae 2024, 10(4), 330; https://doi.org/10.3390/horticulturae10040330 - 28 Mar 2024

Cited by 2 | Viewed by 926

Abstract

The application of cut flower preservation technology can significantly enhance both the ornamental and economic value of fresh-cut flowers. Research on vase solutions has become a concentrated area in current studies on cut flower preservation. Multi-walled carbon nanotubes (MWCNTs), as a type of [...] Read more.

The application of cut flower preservation technology can significantly enhance both the ornamental and economic value of fresh-cut flowers. Research on vase solutions has become a concentrated area in current studies on cut flower preservation. Multi-walled carbon nanotubes (MWCNTs), as a type of carbon nanomaterial with bactericidal and membrane-penetrating properties, can be used as a component in vase solutions. This supplementation of energy substances aims to improve antioxidant enzyme activity, thereby enhancing the postharvest quality of cut chrysanthemums. In this study, deionized water and a standard preservative solution were employed as control groups to compare the effects of MWCNTs applied at different concentrations, combined with common preservatives such as sugar and 8-hydroxyquinoline, on the postharvest flowering and preservation of Chrysanthemum × morifolium ‘Jinba’. By observing the distribution of MWCNTs in the tissues surrounding the cut and changes in water content, carbon sources, osmoregulatory substance levels, and the expression of relevant key genes, a formulation with excellent postharvest treatment effects was identified. Preliminary investigations into its action and mechanism were also conducted. The results indicated that the combined treatment with 5 mg L⁻¹ MWCNTs, 30 g L⁻¹ sucrose, and 0.2 g L⁻¹ 8-hydroxyquinoline effectively promoted water and sugar uptake in chrysanthemum flowers, accelerating bud opening, maintaining larger inflorescence diameter, and extending the vase life. Ultimately, this enhanced the ornamental value of cut chrysanthemums. These research findings provide theoretical and experimental foundations for the application of multi-walled carbon nanotubes as auxiliary additives to improve the ornamental quality of cut flowers. Full article

(This article belongs to the Section Floriculture, Nursery and Landscape, and Turf)

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16 pages, 3715 KiB

Open AccessEditor’s ChoiceArticle

Olive Escudete (Dalmatian Disease) Caused by Botryosphaeria dothidea as a Result of Fly–Midge–Fungus Interaction

by Hani K. Aldebis, Antonio Santos-Rufo, Ibrahim Eldesouki-Arafat, Enrique Vargas-Osuna, Juan Moral, Antonio Trapero and Francisco Javier López-Escudero

Horticulturae 2024, 10(4), 321; https://doi.org/10.3390/horticulturae10040321 - 26 Mar 2024

Viewed by 902

Abstract

Escudete, which is caused by Botryosphaeria dothidea, is a disease that is widely distributed in the Mediterranean basin, but is of little general importance. Nevertheless, serious attacks have been observed on occasion, which have caused a considerable reduction in the quality of [...] Read more.

Escudete, which is caused by Botryosphaeria dothidea, is a disease that is widely distributed in the Mediterranean basin, but is of little general importance. Nevertheless, serious attacks have been observed on occasion, which have caused a considerable reduction in the quality of table olives. The incidence of the pathogen has been associated with damage caused by the olive fly (Bactrocera oleae) and the presence of a possible vector agent, i.e., the midge Prolasioptera berlesiana, whose larvae can feed on fly eggs (although the role the midge may play in the spread of this disease is not well known). Therefore, it is necessary to clarify these interactions to adopt appropriate disease control measures. Studies were conducted in olive orchards planted with the Gordal Sevillana, Picudo, and Hojiblanca olive cultivars. Field surveys were carried out in order to sample their fruits for laboratory analysis, and several bioassays were also performed. Moreover, the population of B. oleae adults was monitored using traps that were baited with food attractants. The results indicated that the three agents developed and evolved in parallel under field conditions. Thus, the midges were attracted by the oviposition punctures caused in fruits by olive fruit flies, regardless of whether the punctures contained eggs. All the investigated olive fruits in which midges were present inside punctures created by olive fruit flies exhibited typical symptoms of escudete, which is necessary for the development of this disease. Forty-eight hours after fly punctures were artificially simulated in the olive fruits, 48.0% of them contained a midge, whereas no midges appeared in the artificially created shapeless wounds in the fruits. This indicates that an olive fly egg is not required for the development of midges; however, they do prefer punctures made by B. oleae. Moreover, when the olive fruits were incubated in a humid chamber, the B. dothidea fungus only appeared in those fruits that contained midges, thus indicating a close relationship between these two agents. Additionally, the midges were able to complete their entire development from egg to adult under controlled conditions, and they fed on the pure cultures of the B. dothidea fungus. Furthermore, although no pathogens were present in the immature midges, some of the pathogens could have been isolated from the inner tissues of the adult female midges. The fact that mycangia is present in the abdomen of P. berlesiana supports the hypothesis that their relationship with B. dothidea may be mutualistic and that they may act as a vector for the fungus. Full article

(This article belongs to the Special Issue Fungal Diseases and Pathogens Affecting Horticultural Crops: New Challenges)

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17 pages, 2441 KiB

Open AccessEditor’s ChoiceArticle

The Discovery of the Potential Attractive Compounds of Bactrocera dorsalis (Hendel)

by Yupeng Chen, Fengqin Cao, Yan Zou, Yi Li, Jian Wen, Yu Fu, Hongai Su, Xue Bai, Xiaowei Xie, Ling Zeng, Guangwen Liang, Duoduo Wang and Yongyue Lu

Horticulturae 2024, 10(3), 299; https://doi.org/10.3390/horticulturae10030299 - 20 Mar 2024

Viewed by 1209

Abstract

Bactrocera dorsalis (Hendel) (B. dorsalis) is an important agricultural invasive pest that causes significant economic losses in tropical and subtropical fruit and vegetable crops. In this study, the proteins related to the sense of smell and taste of B. dorsalis, [...] Read more.

Bactrocera dorsalis (Hendel) (B. dorsalis) is an important agricultural invasive pest that causes significant economic losses in tropical and subtropical fruit and vegetable crops. In this study, the proteins related to the sense of smell and taste of B. dorsalis, such as OBP, PBP, OR, IR, SNMP and CSP, were screened based on B. dorsalis transcriptome data. By integrating the compounds that were reported to be attractive to B. dorsalis, similar compounds of hydrocarbon compounds were obtained. Molecular docking was used to predict the binding between the similar compounds and the OBP, PBP, OR, IR, SNMP and CSP proteins. Network pharmacology was used to screen the potentially attractive compounds, and ecological experiments with B. dorsalis were finally conducted to verify the effect of these potentially attractive compounds on B. dorsalis. The results showed that the G protein-coupled receptor [BR: KO04030] and ion channel [BR: KO04040] pathways were closely related to the odor tropism of B. dorsalis. A total of 84 compounds, such as mitemcinal, exemestane and midecamycin, have potential binding effects on the B. dorsalis odor receptor proteins. The results of the ecological experiments showed that 1 mg/mL and 0.1 mg/mL 19-norandrostenedione, 1 mg/mL progesterone compounds was significantly attractive to B. dorsalis males, while 0.1 mg/mL exemestane was significantly attractive to B. dorsalis females. In this study, network pharmacology technology was used to discover the potential attractive compounds for B. dorsalis, which is important for the development and subsequent prevention and control of B. dorsalis. It can provide a reference in improving the success rates of clinical trials of new pest control products and in reducing the time and cost of drug development. Full article

(This article belongs to the Special Issue Integrated Pest Management of Fruit Trees and Other Horticultural Crops)

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19 pages, 6096 KiB

Open AccessEditor’s ChoiceArticle

Physiological and Transcriptional Characteristics of Banana Seedlings in Response to Nitrogen Deficiency Stress

by Lei Zhao, Bingyu Cai, Xiaohan Zhang, Bencheng Zhang, Junting Feng, Dengbo Zhou, Yufeng Chen, Miaoyi Zhang, Dengfeng Qi, Wei Wang, Jianghui Xie and Yongzan Wei

Horticulturae 2024, 10(3), 290; https://doi.org/10.3390/horticulturae10030290 - 18 Mar 2024

Cited by 2 | Viewed by 1472

Abstract

Nitrogen is a crucial element for the growth and development of plants, directly affecting crop growth and yield. To investigate the physiological and molecular mechanism of nitrogen-deficiency stress, we conducted an investigation into the effects of different nitrogen levels on the growth, photosynthetic [...] Read more.

Nitrogen is a crucial element for the growth and development of plants, directly affecting crop growth and yield. To investigate the physiological and molecular mechanism of nitrogen-deficiency stress, we conducted an investigation into the effects of different nitrogen levels on the growth, photosynthetic characteristics, and gene transcription levels of banana seedlings. Compared with the control group with normal nitrogen levels (NN), the height of plants receiving Reduced-N (NR), Low-N (LN), and N-Free (NF) treatments was decreased by 0.45 cm, 2.5 cm, and 3.25 cm, respectively. Their dry weight was reduced by 1.63 g, 2.99 g, and 2.88 g, respectively. Conversely, the dry weight of the underground plant part in the LN and NF treatment groups exhibited an increase of 0.13 g and 0.16 g, respectively. Regarding photosynthetic characteristics, the Specialty Products Agricultural Division (SPAD) values of the NR, LN, and NF treatments showed reductions of 15.5%, 30.4%, and 35.9%, respectively, compared with those of the control treatments. The values of maximum photosynthetic efficiency (Fv/Fm), actual photosynthetic efficiency (Y(Ⅱ)), and relative electron transfer (ETR) of the banana seedlings decreased to different degrees after NR, LN, and NF treatment, and their values were positively correlated with N levels. Gene transcription analysis showed that N transport-related proteins, including NRT1.7, NRT2.3a, NRT2.3b, and NRT2.5, were significantly up-regulated to increase the nitrogen absorption capacity of plant roots. On the other hand, various transcription factors including GRAS, MYB, and WRKY were notably up-regulated, facilitating root growth and the expanding root absorption area, thereby enhancing nitrogen uptake. Furthermore, genes associated with endogenous hormone metabolic pathways such as gibberellin (GA), strigolactone (SL), and brassinosteroids (BR) were activated in banana plants subjected to low nitrogen stress, enhancing the plant’s ability to adapt to nitrogen-deficient conditions. These findings offer valuable insights into understanding the transcriptional regulatory mechanisms governing banana responses to low nitrogen stress and breeding new varieties with improved nutrient utilization. Full article

(This article belongs to the Special Issue Horticultural Plant Nutrition, Fertilization, Soil Management)

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17 pages, 4918 KiB

Open AccessEditor’s ChoiceArticle

Integrative Metabolome and Transcriptome Analyses Reveal the Pericarp Coloration Mechanisms in Bitter Melon (Momordica charantia L.)

by Liang Yang, Zhi Li, Ju Li, Yanqin Ma, Mingjun Miao, Haicheng Long, Yujie Zhou and Wei Chang

Horticulturae 2024, 10(3), 291; https://doi.org/10.3390/horticulturae10030291 - 18 Mar 2024

Cited by 1 | Viewed by 1302

Abstract

Pericarp colors are critical agronomic traits that affect the quality and economic values of fruits. Although a diversity of bitter melon pericarp (BMP) colors is available, the fruit pigmentation mechanisms remain elusive. Hence, this study aimed to unveil the key metabolites and molecular [...] Read more.

Pericarp colors are critical agronomic traits that affect the quality and economic values of fruits. Although a diversity of bitter melon pericarp (BMP) colors is available, the fruit pigmentation mechanisms remain elusive. Hence, this study aimed to unveil the key metabolites and molecular mechanisms underlying variation in BMP coloration through integrative metabolomics and transcriptomics analyses of four differently colored genotypes, including K1102 (grayish orange), 262 (grayish yellow), 1392 (very soft green), and K115 (dark grayish cyan). The four BMPs exhibited significant metabolite profile and transcriptional differences, as over 112 and 1865 DAMs (differentially accumulated metabolites) and DEGs (differentially expressed genes), respectively, were identified. The variation in the content of six anthocyanins, including malvidin 3-O-glucoside, petunidin 3-O-glucoside, rosinidin O-hexoside, cyanidin, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside, and pelargonidin 3-O-beta-D-glucoside, might be the major driving factor of BMP color changes. Notably, malvidin 3-O-glucoside, rosinidin O-hexoside, and petunidin 3-O-glucoside are the dominant pigments in K115, while carotenoids and other flavonoids may contribute to other colors. Candidate flavonoid structural and regulatory (MYBs, NACs, MADSs, bHLHs, and bZIPs) genes were identified. Of them, gene13201 (anthocyanin reductase), gene8173 (polyphenol oxidase), gene2136 (NAC43), gene19593 (NAC104), and gene15171 (tetrapyrrole-binding protein) might play essential roles in K115 pericarp color development. Our findings deepen our understanding of BMP pigmentation and provide fundamental resources for higher-valued bitter melon breeding perspectives. Full article

(This article belongs to the Special Issue The Physiology, Molecular Biology, Biochemistry and Photoсhemistry in Horticultural Plant)

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16 pages, 2423 KiB

Open AccessEditor’s ChoiceArticle

Integrative Phytohormone and Transcriptome Analyses Reveal the Inhibitory Mechanism of Ethylene on Potato Tuber Sprouting at Room Temperature

by Meixue Zhang, Wenxiao Jiao, Qingmin Chen, Maorun Fu and Cong Han

Horticulturae 2024, 10(3), 286; https://doi.org/10.3390/horticulturae10030286 - 17 Mar 2024

Cited by 1 | Viewed by 1178

Abstract

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, [...] Read more.

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, Eth’s inhibitory effects on tuber sprouting at room temperature were investigated. The potential molecular mechanisms of Eth-induced sprout suppression were revealed by phytohormone and transcriptome analyses. Results showed that exogenous Eth significantly suppressed sprout growth in potato tubers during two weeks of storage. The endogenous plant hormone levels of abscisic acid (ABA) and auxin (Aux) were markedly reduced by Eth treatment. Transcriptomic analysis revealed that more transcriptional changes occurred in the early stage of sprouting. The differentially expressed genes (DEGs) assigned to the pathways of plant hormone signal transduction, photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis, which were closely associated with sprouting, were extensively down-regulated by Eth treatment. In addition, the heat map of six hormone signal transduction pathways showed that the expression of most DEGs annotated into the Aux signal transduction pathway was suppressed by Eth treatment, while the expression of many DEGs annotated as ETR (Eth receptor) and ERF1/2 (Eth-responsive transcription factor 1 and 2) in the Eth signal transduction pathway was enhanced by Eth treatment. Taken together, our results indicated that Eth-induced sprout inhibition might be closely related to the suppression of internal Aux production and signal transduction and the activation of Eth signal transduction. Full article

(This article belongs to the Special Issue Postharvest Physiology and Quality Maintaining of Horticultural Plants)

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17 pages, 7154 KiB

Open AccessEditor’s ChoiceArticle

LbHSP17.9 Participated in the Regulation of Cold Stress in Cut Lily Flowers

by Jiahui Zhao, Xinyu Yan, Wei Huang, Cheng Liu, Xuan Hao, Chengye Gao, Minghua Deng and Jinfen Wen

Horticulturae 2024, 10(3), 287; https://doi.org/10.3390/horticulturae10030287 - 17 Mar 2024

Viewed by 995

Abstract

Heat shock proteins (HSPs) play important roles in plant stress resistance, but it is not clear whether small molecular HSPs (sHSPs) are involved in the cold stress resistance of lily flowers. In this study, we cloned LbHSP17.9 and found that its expression was [...] Read more.

Heat shock proteins (HSPs) play important roles in plant stress resistance, but it is not clear whether small molecular HSPs (sHSPs) are involved in the cold stress resistance of lily flowers. In this study, we cloned LbHSP17.9 and found that its expression was up-regulated under cold stress. When LbHSP17.9 was silenced (TRV2::LbHSP17.9) using virus-induced gene silencing in cut lily flowers, the content of malondialdehyde was increased under 4 °C stress treatment. The catalase (CAT) activity in TRV2::LbHSP17.9 was significantly lower than in TRV2 in the first 7 days, and the peroxidase (POD) activity in TRV2::LbHSP17.9 was significantly lower than in TRV2 after 4 days of 4 °C stress. Further analysis showed that the transcription levels of LbCu/ZnSOD, LbMnSOD and LbCAT in TRV2::LbHSP17.9 were lower than those of TRV2 under 4 °C stress. When LbHSP17.9 was overexpressed in lily petal disks, the OE-LbHSP17.9 disks faded later than the controls at 4 °C and the relative conductivity decreased significantly. Overexpression of LbHSP17.9 in Arabidopsis thaliana resulted in fewer injury symptoms and lower MDA content than wild type under 4 °C stress. Therefore, we speculate that LbHSP17.9 can improve the resistance of lily flowers to cold stress. Full article

(This article belongs to the Section Biotic and Abiotic Stress)

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19 pages, 17321 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Seed Morphological Analysis in Species of Vitis and Relatives

by José Javier Martín-Gómez, José Luis Rodríguez-Lorenzo, Diego Gutiérrez del Pozo, Félix Cabello Sáez de Santamaría, Gregorio Muñoz-Organero, Ángel Tocino and Emilio Cervantes

Horticulturae 2024, 10(3), 285; https://doi.org/10.3390/horticulturae10030285 - 16 Mar 2024

Cited by 2 | Viewed by 1400

Abstract

Seed shape descriptions of species of Vitis have traditionally been based on adjectives comparing overall shape with geometric figures, such as oval, elongated oval, and pear-shaped, corresponding to higher values of the Stummer index (lower aspect ratio) for oval, and lower values of [...] Read more.

Seed shape descriptions of species of Vitis have traditionally been based on adjectives comparing overall shape with geometric figures, such as oval, elongated oval, and pear-shaped, corresponding to higher values of the Stummer index (lower aspect ratio) for oval, and lower values of the Stummer index for pear shape (or elongated seeds, with a higher aspect ratio). Analytical, quantitative descriptions of shape have recently been applied to diverse genera of Vitaceae and cultivated varieties of Vitis. Here, we present the application of three quantitative methods to the seed shape description of ten species of the genus Vitis and three species of related genera (Ampelopsis, Cissus and Parthenocissus). First, general seed shape was described through comparisons using geometric models. For this, the average silhouettes of representative seed populations were used as models for shape quantification. Two additional quantitative methods were based on the measurement of bilateral symmetry and curvature analysis in the apex. Quantitative methods for shape description based on similarity with the models give an accurate account of the relationships between Vitis species. The resulting dendrogram is like the dendrogram obtained from a combined analysis using the data from general measurements and curvature and symmetry analyses. The original methods presented here for seed morphology are useful for analyzing the phylogenetic relationships between species of Vitis. Full article

(This article belongs to the Section Propagation and Seeds)

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15 pages, 2961 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Salinity and Drought on the Essential Oil Yield and Quality of Various Plant Species of the Lamiaceae Family (Mentha spicata L., Origanum dictamnus L., Origanum onites L.)

by Michalis K. Stefanakis, Anastasia E. Giannakoula, Georgia Ouzounidou, Charikleia Papaioannou, Vaia Lianopoulou and Eleni Philotheou-Panou

Horticulturae 2024, 10(3), 265; https://doi.org/10.3390/horticulturae10030265 - 10 Mar 2024

Cited by 1 | Viewed by 1317

Abstract

Mentha spicata L., Origanum dictamnus L., and Origanum onites L. are aromatic plants that produce very important essential oils. They are considered model plants with beneficial health properties due to their antioxidant content. Enhancing the yield while maintaining the quality of essential oil [...] Read more.

Mentha spicata L., Origanum dictamnus L., and Origanum onites L. are aromatic plants that produce very important essential oils. They are considered model plants with beneficial health properties due to their antioxidant content. Enhancing the yield while maintaining the quality of essential oil is of significant commercial importance. Salinization and drought cause various effects on the yield and quality of the bioactive constituents in essential oil. By assessing the response of these plants and their secondary metabolites accumulation to different salt stress and irrigation levels, this study aims to gain insights into how plants adapt to and cope with salinity and drought. A pot experiment was conducted in the spring of 2020 to assess the effect of salinity and drought stress on the growth and essential oils content of the three aromatic plant species mentioned above. The soil mixture used was perlite and peat in a ratio of 1:1:6, while four salinity treatments (25, 50, 100, and 150 mΜ NaCl) and two levels of irrigation were applied (100% and 50%). Salinity significantly affects total chlorophyll concentration especially in higher concentrations (100 and 150 mM) in M. spicata plants, especially under 50% soil water irrigation. Under the same conditions, M. spicata contained the higher proline concentration, which was significantly greater than that in O. dictamnus and O. onites. Similar variations of malondialdehyde and hydrogen hyperoxide were revealed among the three species, with significantly higher values in M. spicata when subjected to both excess salinity and drought conditions. The major compounds identified in M. spicata were carvone, in O. dictamnus carvacrol, and p-cymene and in O. onites carvacrol. It is important to highlight that O. onites had the highest concentration of essential oil, and that the concentration increased with the increase of NaCl. This suggests that the presence of NaCl in the soil may have a stimulating effect on the production of essential oil in O. onites. However, it is plausible that the stress caused by NaCl triggers a physiological response in O. onites, leading to increased production of essential oil. This could be a protective mechanism to enhance the plant’s resistance to the stressor. Overall, O. onites and O. dictamnus appeared to be more resistant to these stress conditions than M. spicata, since they maintained their growth and essential oil quality indicators at higher levels. These two species possess mechanisms that prevent or minimize lipid peroxidation, thus protecting their cell membranes and maintaining their ultrastructure integrity. Full article

(This article belongs to the Special Issue Horticulture Plants Stress Physiology)

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14 pages, 8671 KiB

Open AccessEditor’s ChoiceArticle

Genome-Wide Identification of the PEBP Family Gene in Three Cymbidium Species and Its Expression Patterns Analysis in C. ensifolium

by Jinliao Chen, Fei Wang, Yangting Zhang, Ruiyue Zheng, Xiaopei Wu, Ye Ai, Sagheer Ahmad, Zhongjian Liu and Donghui Peng

Horticulturae 2024, 10(3), 252; https://doi.org/10.3390/horticulturae10030252 - 6 Mar 2024

Viewed by 1141

Abstract

The PEBP gene family is involved in many biological processes in plants, including plant growth and development, flowering regulation, light response, and abiotic stress response. But there is little information about the role of the PEBP gene family in Cymbidium species. In this [...] Read more.

The PEBP gene family is involved in many biological processes in plants, including plant growth and development, flowering regulation, light response, and abiotic stress response. But there is little information about the role of the PEBP gene family in Cymbidium species. In this study, we identified 11, 9, and 7 PEBP genes in C. ensifolium, C. sinense, and C. goeringii, respectively, and mapped them to the chromosomes. We also studied the physicochemical characteristics of the proteins encoded by these PEBPs and analyzed their intra-species collinearity, gene structure, conserved motifs, and cis-acting elements. Furthermore, a total of forty PEBP genes from C. sinense, C. ensifolium, C. goeringii, Phalaenopsis, and Arabidopsis were divided into three clades based on the phylogenetic tree. The expression patterns of 11 PEBP genes in different tissues and organs of C. ensifolium were analyzed based on transcriptome data, indicating that the CePEBPs might play an important role in the growth and development, especially in the flower bud organs (1–5 mm). CePEBP5 plays an indispensable role in both the vegetative and reproductive growth cycles of C. ensifolium. CePEBP1 is essential for root development, while CePEBP1, CePEBP3, CePEBP5, and CePEBP10 regulate the growth and development of different floral organ tissues at various stages. The findings of this study can do a great deal to understand the roles of the PEBP gene family in Cymbidium. Full article

(This article belongs to the Special Issue Advancement in Propagation, Breeding, Cultivation and Marketing of Ornamentals)

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12 pages, 4251 KiB

Open AccessEditor’s ChoiceArticle

Efficient and Direct Identification of Ditylenchus destructor and D. dipsaci in Soil and Plant Tissues Using a Species-Specific PCR Assay

by Xu Han, Qing Chang, Youxian Xu, Pengjun Wang, Huixia Li, Yunqing Li, Yanshan Li, Wenkun Huang, Lingan Kong, Shiming Liu, Deliang Peng and Huan Peng

Horticulturae 2024, 10(3), 250; https://doi.org/10.3390/horticulturae10030250 - 5 Mar 2024

Viewed by 1217

Abstract

Ditylenchus destructor and D. dipsaci are important nematodes that have a significant economic impact on agronomic and horticultural plants worldwide. Microscopic observation alone may not distinguish between D. destructor and D. dipsaci. Accurate and rapid identification of these two species is essential [...] Read more.

Ditylenchus destructor and D. dipsaci are important nematodes that have a significant economic impact on agronomic and horticultural plants worldwide. Microscopic observation alone may not distinguish between D. destructor and D. dipsaci. Accurate and rapid identification of these two species is essential for effective pest management. In the present study, a species-specific PCR assay was developed to detect and differentiate D. destructor and D. dipsaci based on the rDNA-ITS sequences. The primers developed in this study can specifically amplify fragments of DNA from D. destructor and D. dipsaci in the target population, without amplifying DNA from other non-target nematodes within the genus Ditylenchus. The sensitivity test revealed that this procedure has the ability to detect single second-stage juveniles (J2) of D. dipsaci at a dilution of 1/128 and D. destructor at a dilution of 1/64. Additionally, it can detect genomic DNA (gDNA) at concentrations of 10 pg/µL for D. dipsaci and 1 ng/µL for D. destructor. These results align with previously reported results obtained through RPA and LAMP methods. Furthermore, the primers developed in this study for D. destructor not only were able to amplify six different haplotypes of nematodes but also successfully detected it in infested plant roots and soil samples, thereby shortening the time and reducing the number of steps required for detection. Thus, this assay, which does not necessitate taxonomic or morphological expertise, significantly enhances the diagnosis of D. destructor and D. dipsaci in infested fields. This advancement aids in the early control of these nematodes. Full article

(This article belongs to the Special Issue Mitigating Soil-Borne Diseases in Horticultural Crops: Current Challenges and Management Strategies)

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17 pages, 2439 KiB

Open AccessEditor’s ChoiceArticle

Effects of Long-Term High Temperatures in the Root Zone on the Physiological Characteristics of Grapevine Leaves and Roots: Implications for Viticulture Practices

by Yifan Su, Xinfeng Li, Zhiyi Cao, Zhen Gao and Yuanpeng Du

Horticulturae 2024, 10(3), 245; https://doi.org/10.3390/horticulturae10030245 - 3 Mar 2024

Cited by 1 | Viewed by 993

Abstract

Ridging cultivation and root restriction cultivation are beneficial due to their improvement of the soil permeability in the root zone of grapevine, and they are widely used in southern China, Japan, and other countries. However, with the intensification of global warming, when using [...] Read more.

Ridging cultivation and root restriction cultivation are beneficial due to their improvement of the soil permeability in the root zone of grapevine, and they are widely used in southern China, Japan, and other countries. However, with the intensification of global warming, when using ridging or root restriction cultivation, the soil temperature in the root zone can often reach 30 °C or even more than 35 °C during the summer, which is not conducive to the growth of grapevines. The aim of this study was to explore the effects of high root zone temperatures on the photosynthetic fluorescence characteristics of grapevine leaves, root respiration, and degree of lignification of roots and shoots, as well as to provide a theoretical foundation for the management of grapevine production and cultivation. One-year-old potted ‘Kyoho’ was used as the study material. Three root temperature treatments were implemented for 15 days (9:00–16:00): 25 °C (CK), 30 °C (T1), and 35 °C (T2). The results showed that the malondialdehyde and H₂O₂ levels in leaves increased, while the chlorophyll content decreased. The oxygen-evolving complex was inactivated, and PSII donor and acceptor sides were blocked, thus reducing the photosynthetic gas exchange capacity at high root zone temperatures. The grapevine root activity and root/shoot ratio decreased. Simultaneously, the lignin content in the roots and shoots increased. In addition, there was a significant increase in the expression of key genes (PAL, C4H, 4CL, F5H, COMT, CCR, and CAD) in the root lignin synthesis pathway. Heightened root zone temperatures increased cyanide-resistant respiration in roots and heat release in the PPP pathway to alleviate stress damage. Therefore, it is recommended to use grass, mulching, and other cultivation management methods to maintain root zone temperatures below 30 °C in order to ensure the normal growth of grapevines and promote a high and stable yield. Full article

(This article belongs to the Special Issue Advances in Gene Regulation and Genetic Improvement of Fruit Trees)

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26 pages, 5738 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Identification and Pathogenicity of Biscogniauxia and Sordaria Species Isolated from Olive Trees

by Elena Petrović, Sara Godena, Jasenka Ćosić and Karolina Vrandečić

Horticulturae 2024, 10(3), 243; https://doi.org/10.3390/horticulturae10030243 - 2 Mar 2024

Cited by 3 | Viewed by 1458

Abstract

A field investigation of olive trees in Istria, Croatia, revealed branch dieback and cracked bark. Samples of diseased branches were collected from eight different locations and analysed. Additionally, meteorological data from two locations were analysed to determine if there was a connection between [...] Read more.

A field investigation of olive trees in Istria, Croatia, revealed branch dieback and cracked bark. Samples of diseased branches were collected from eight different locations and analysed. Additionally, meteorological data from two locations were analysed to determine if there was a connection between climatic changes and the appearance of pathogens in the region. Pathogenicity tests were conducted on olive seedlings. This study provides a description of Biscogniauxia and Sordaria species’ morphology and elucidates their phylogeny based on the internal transcribed spacer (ITS), beta-tubulin (TUB2) and translation elongation factor 1-alpha (TEF1- α) regions. This research represents the first documented occurrence of Biscogniauxia mediterranea causing charcoal disease in olive trees in Croatia. Additionally, it is the first report of Biscogniauxia nummularia (Bull.) Kuntze and Sordaria fimicola causing diseases in olive trees anywhere in the world. Furthermore, this study marks one of the initial forays into molecular investigations of these species isolated from olive trees. Considering the potential threat posed by the inherent aggressiveness of Biscogniauxia species, further research is deemed necessary to curb the development of charcoal disease. Full article

(This article belongs to the Special Issue Sustainable Production of Fruit Trees and Disease Resistance)

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20 pages, 4038 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Spatial Variability of Grape Berry Maturation Program at the Molecular Level

by Ron Shmuleviz, Alessandra Amato, Pietro Previtali, Elizabeth Green, Luis Sanchez, Maria Mar Alsina, Nick Dokoozlian, Giovanni Battista Tornielli and Marianna Fasoli

Horticulturae 2024, 10(3), 238; https://doi.org/10.3390/horticulturae10030238 - 29 Feb 2024

Viewed by 1875

Abstract

The application of sensors in viticulture is a fast and efficient method to monitor grapevine vegetative, yield, and quality parameters and determine spatial intra-vineyard variability. Molecular analysis at the gene expression level can further contribute to the understanding of the observed variability by [...] Read more.

The application of sensors in viticulture is a fast and efficient method to monitor grapevine vegetative, yield, and quality parameters and determine spatial intra-vineyard variability. Molecular analysis at the gene expression level can further contribute to the understanding of the observed variability by elucidating how pathways contributing to different grape quality traits behave in zones diverging on any of these parameters. The intra-vineyard variability of a Cabernet Sauvignon vineyard was evaluated through a Normalized Difference Vegetation Index (NDVI) map calculated from a multispectral image and detailed ground-truthing (e.g., vegetative, yield, and berry ripening compositional parameters). The relationships between NDVI and ground measurements were explored by correlation analysis. Moreover, berries were investigated by microarray gene expression analysis performed at five time points from fruit set to full ripening. Comparison between the transcriptomes of samples taken from locations with the highest and lowest NDVI values identified 968 differentially expressed genes. Spatial variability maps of the expression level of key berry ripening genes showed consistent patterns aligned with the vineyard vigor map. These insights indicate that berries from different vigor zones present distinct molecular maturation programs and suggest that transcriptome analysis may be a valuable tool for the management of vineyard variability. Full article

(This article belongs to the Section Viticulture)

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13 pages, 2481 KiB

Open AccessEditor’s ChoiceArticle

Effects of N, P, K Nutrition Levels on the Growth, Flowering Attributes and Functional Components in Chrysanthemum morifolium

by Kaifang Jiang, Shu Peng, Zimeng Yin, Xiaohui Li, Lei Xie, Meichen Shen, Dahui Li and Junshan Gao

Horticulturae 2024, 10(3), 226; https://doi.org/10.3390/horticulturae10030226 - 27 Feb 2024

Cited by 1 | Viewed by 1486

Abstract

Fertilizer application is a decisive measure for the productivity of medicinal chrysanthemum plants. Therefore, determining the optimal doses of nutrients required for the growth and yield is crucial. In this study, we set out to investigate the effect of various nutrients on the [...] Read more.

Fertilizer application is a decisive measure for the productivity of medicinal chrysanthemum plants. Therefore, determining the optimal doses of nutrients required for the growth and yield is crucial. In this study, we set out to investigate the effect of various nutrients on the growth, yield, and functional components of chrysanthemum under eight different fertilization levels at seedling, branching, and flowering growth periods. The results show that plant height, stem diameter, and leaf area under the balance fertilization treatment were the highest (82 cm, 0.78 cm, and 38.50 cm², respectively), while the flower size and yield under the high potassium treatment were significantly increased compared to using balance fertilization. Chlorophyll content was also highest under the high potassium treatment. Moreover, plant defensive antioxidant peroxidase (POD) was responsive to low nitrogen treatment and low phosphorus treatment, while high potassium treatment enhanced the phenylalanine aminolase (PAL) activity and increased the content of flavonoids and chlorogenic acid in Chrysanthemum morifolium. In addition, low phosphorus treatment promoted the accumulation of flavonoids and chlorogenic acid content. Convincingly, the results show that growth, flowering, and functional indicators of chrysanthemum may thrive best under high potassium and balanced fertilization dosages, which will contribute to the development of a new economical chrysanthemum fertilizer ratio. Full article

(This article belongs to the Section Plant Nutrition)

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19 pages, 4545 KiB

Open AccessEditor’s ChoiceArticle

Combining Recurrent Neural Network and Sigmoid Growth Models for Short-Term Temperature Forecasting and Tomato Growth Prediction in a Plastic Greenhouse

by Yi-Shan Lin, Shih-Lun Fang, Le Kang, Chu-Chung Chen, Min-Hwi Yao and Bo-Jein Kuo

Horticulturae 2024, 10(3), 230; https://doi.org/10.3390/horticulturae10030230 - 27 Feb 2024

Cited by 1 | Viewed by 1294

Abstract

Compared with open-field cultivation, greenhouses can provide favorable conditions for crops to grow through environmental control. The prediction of greenhouse microclimates is a way to reduce environmental monitoring costs. This study used several recurrent neural network models, including long short-term memory (LSTM), gated [...] Read more.

Compared with open-field cultivation, greenhouses can provide favorable conditions for crops to grow through environmental control. The prediction of greenhouse microclimates is a way to reduce environmental monitoring costs. This study used several recurrent neural network models, including long short-term memory (LSTM), gated recurrent unit, and bi-directional LSTM, with varying numbers of hidden layers and units, to establish a temperature forecasting model for a plastic greenhouse. To assess the generalizability of the proposed model, the most accurate forecasting model was used to predict the temperature in a greenhouse with different specifications. During a test period of four months, the best proposed model’s R², MAPE, and RMSE values were 0.962, 3.216%, and 1.196 °C, respectively. Subsequently, the outputs of the temperature forecasting model were used to calculate growing degree days (GDDs), and the predicted GDDs were used as an input variable for the sigmoid growth models to simulate the leaf area index, fresh fruit weight, and aboveground dry matter of tomatoes. The R² values of the growth model for the three growth traits were all higher than 0.80. Moreover, the fitted values and the parameter estimates of the growth models were similar, irrespective of whether the observed GDD (calculated using the actual observed data) or the predicted GDD (calculated using the temperature forecasting model output) was used. These results indicated that the proposed temperature forecasting model could accurately predict the temperature changes inside a greenhouse and could subsequently be used for the growth prediction of greenhouse tomatoes. Full article

(This article belongs to the Special Issue Controlled Environment Horticulture: Latest Advances and Future Prospects)

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11 pages, 1952 KiB

Open AccessEditor’s ChoiceArticle

Identification of an Entomopathogenic Fungus, Pseudozyma flocculosa (Traquair, Shaw & Jarvis), and Its Efficacy against Tetranychus urticae Koch

by Yan Zhang, Rui Dong, Shouyin Hu, Zhaojiang Guo and Shaoli Wang

Horticulturae 2024, 10(3), 221; https://doi.org/10.3390/horticulturae10030221 - 25 Feb 2024

Viewed by 1288

Abstract

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests worldwide, with chemical application being the primary control method. However, frequent heavy use or misuse of insecticides has accelerated the development of varying degrees of resistance in T. [...] Read more.

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests worldwide, with chemical application being the primary control method. However, frequent heavy use or misuse of insecticides has accelerated the development of varying degrees of resistance in T. urticae. This makes the chemical control of this mite more challenging. Biocontrol methods have attracted much attention due to their safety and environment-friendly impact. Based on previous observations that the population of T. urticae was infected by unknown pathogenic fungi, we isolated, identified, and evaluated the pathogenicity of the fungi from infected mites. Through available morphological and molecular identification, the fungus was identified as Pseudozyma flocculosa. The virulence activity of the strain was evaluated at different concentrations of spore suspension (10⁶–10⁹ conidia/mL) using a spraying method. The strain showed pathogenic activity against the T. urticae in adult females that varied with different concentrations and temperatures. Meanwhile, the P. flocculosa also had a significant toxic effect on the developmental stages of T. urticae. In the laboratory bioassay, the mortality rate of the tested mites reached 100% at 9 d after P. flocculosa treatment. Additionally, a wettable powder processed with P. flocculosa conidia was applied on the T. urticae in the greenhouse and the control efficacy reached up to 90% at 7 d after treatment. The results showed a high insecticidal activity of P. flocculosa against T. urticae, indicating that this fungus possesses great potential for use as a bio-insecticidal agent. Full article

(This article belongs to the Special Issue Advancement in Mechanism of Vegetable Pest Catastrophe and Green Prevention and Control)

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12 pages, 2118 KiB

Open AccessEditor’s ChoiceArticle

Active Packaging Systems to Extend the Shelf Life of ‘Italia’ Table Grapes

by Maíra Tiaki Higuchi, Aline Cristina de Aguiar, Nathalia Rodrigues Leles, Luana Tainá Machado Ribeiro, Bruna Evelise Caetano Bosso, Fábio Yamashita, Khamis Youssef and Sergio Ruffo Roberto

Horticulturae 2024, 10(3), 214; https://doi.org/10.3390/horticulturae10030214 - 23 Feb 2024

Cited by 1 | Viewed by 1338

Abstract

Sulfur dioxide (SO₂)-generating pads associated with perforated plastic liners are often used to control gray mold in table grapes during cold storage; however, SO₂ may cause bleaching, shattered berries, and an unwanted taste. To overcome this difficulty, a field ultrafast [...] Read more.

Sulfur dioxide (SO₂)-generating pads associated with perforated plastic liners are often used to control gray mold in table grapes during cold storage; however, SO₂ may cause bleaching, shattered berries, and an unwanted taste. To overcome this difficulty, a field ultrafast SO₂-generating pad was designed to be used for a few hours before packaging grape bunches as an alternative for eradicating spores of fungi from berry skin. This study aimed to assess the postharvest conservation and shelf life of ‘Italia’ table grapes packaged in plastic clamshells and perforated plastic liners using the field ultra-fast SO₂-generating pads before packaging, associated with or without slow- or dual-phase SO₂-generating pads during cold storage. The packaged grapes were cold stored (1.0 ± 1.0 °C; 95% relative humidity), and after 45 d, grapes were placed at room temperature (22.0 ± 1.0 °C) without plastic liners and SO₂-generating pads for 3 d. Before and after the grapes had been subjected to the field ultra-fast SO₂-generating pads, the quantification of filamentous fungi on the surface of the berries was assessed. The use of field ultra-fast SO₂-generating pads before packaging, associated with slow- or dual-phase SO₂-generating pads during cold storage, resulted in a lower incidence of gray mold after 45 d of storage, with low weight loss and shattered berries, good preservation of stem freshness, and no impairment in the color and firmness of the berries. Additionally, a significant decrease in disease incidence was observed when using only the dual-phase SO₂-generating pads in cold storage, with good maintenance of bunch quality. Full article

(This article belongs to the Special Issue Advances in Postharvest Packaging and Preservation Techniques)

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16 pages, 2397 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of Genetic Diversity and Agronomic Traits of Germplasm Resources of Stropharia rugosoannulata

by Miao Gu, Qiang Chen, Yan Zhang, Yongchang Zhao, Li Wang, Xiangli Wu, Mengran Zhao and Wei Gao

Horticulturae 2024, 10(3), 213; https://doi.org/10.3390/horticulturae10030213 - 23 Feb 2024

Viewed by 1338

Abstract

China possesses abundant wild germplasm resources and a wide range of cultivated strains of Stropharia rugosoannulata. However, issues such as genetic diversity and unclear genetic relationships have had an impact on the classification and preservation of germplasm resources, the breeding of new [...] Read more.

China possesses abundant wild germplasm resources and a wide range of cultivated strains of Stropharia rugosoannulata. However, issues such as genetic diversity and unclear genetic relationships have had an impact on the classification and preservation of germplasm resources, the breeding of new varieties, and the promotion of superior strains. There is an urgent need for genetic diversity analysis and assessment of germplasm resources. In this study, we conducted whole-genome resequencing of 50 cultivated and wild strains collected from various regions across the country. After applying a series of filtering parameters, we obtained 888,536 high-quality Single Nucleotide Polymorphism (SNP) markers. Using these SNP markers, we performed principal component analysis, population structure analysis, and phylogenetic clusters analysis on the 50 strains. Most cultivated strains exhibited high genetic similarity, while significant genetic diversity was observed among wild strains. Based on factors such as marker distribution throughout the entire genome and marker quality, we selected 358 core SNP markers to construct SNP fingerprints. Two-dimensional barcodes were generated for each strain to enable specific identification. Additionally, the mycelial growth rate of strains was evaluated on Potato Dextrose Agar (PDA) and substrate culture media. We also assessed their lignin degradation capability using guaiacol agar plates assay. It was observed that the mycelial growth rate on PDA and substrate culture medium exhibited a significant correlation with the diameter of the mycelial colony on guaiacol agar medium. Additionally, the correlation between the mycelial growth rate on the substrate medium and that on the guaiacol agar plate was stronger than that on PDA medium. This study provided molecular-level identification and assessment of germplasm resources. It clarified the genetic relationships among strains and the characteristics of mycelium growth-related agronomic traits of each strain. This research contributed to the enrichment and development of utilizable germplasm resources and breeding materials for S. rugosoannulata, offering a scientific basis for further research. Full article

(This article belongs to the Special Issue The Edible Mushroom Industry: A Vital Component in Horticultural Production)

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12 pages, 6401 KiB

Open AccessEditor’s ChoiceArticle

Bioactive Compounds in the Residue Obtained from Fruits of Some Cultivars of Lonicera caerulea

by Sina Cosmulescu, Loredana Vijan, Ivona Cristina Mazilu and Georgiana Badea

Horticulturae 2024, 10(3), 211; https://doi.org/10.3390/horticulturae10030211 - 23 Feb 2024

Cited by 1 | Viewed by 1022

Abstract

This paper aimed to investigate the bioactive compounds in the dry powder residue of honeysuckle cultivars after extracting the juice. Based on the analyses performed on the total content of phenolic compounds, flavonoids, anthocyanins, tannins, carotenoids and vitamin C, the results indicated that [...] Read more.

This paper aimed to investigate the bioactive compounds in the dry powder residue of honeysuckle cultivars after extracting the juice. Based on the analyses performed on the total content of phenolic compounds, flavonoids, anthocyanins, tannins, carotenoids and vitamin C, the results indicated that dried Lonicera caerulea residue represented a rich source of phenolic compounds (8041.36 mg GAE 100 g⁻¹), of which about 80% were tannins (6432.10 mg GAE 100 g⁻¹). The flavonoid content varied around 2436.95 mg CE 100 g⁻¹. Vitamin C (185 mg 100 g⁻¹), lycopene and β-carotene (over 2.5 and 2.8 mg 100 g⁻¹, respectively) were also quantified. Among the phenolic acids, chlorogenic acid predominated (316 mg 100 g⁻¹), followed by cryptochlorogenic acid (135 mg 100 g⁻¹) and neochlorogenic acid (32 mg 100 g⁻¹). Flavonoids were mainly represented by catechin (2594 mg 100 g⁻¹) and anthocyanins (1442 mg 100 g⁻¹). Similar amounts of epicatechin and rutin were measured (156 mg 100 g⁻¹ and 148 mg 100 g⁻¹), while the isoquercetin concentration was below 15 mg 100 g⁻¹. In conclusion, the high level of phytocompounds and the diverse composition of dry Lonicera caerulea residue support its high nutraceutical value and high health-promoting potential. Full article

(This article belongs to the Section Developmental Physiology, Biochemistry, and Molecular Biology)

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14 pages, 776 KiB

Open AccessEditor’s ChoiceArticle

High Outcrossing Levels among Global Macadamia Cultivars: Implications for Nut Quality, Orchard Designs and Pollinator Management

by Stephen J. Trueman, Mark G. Penter, Kátia Sampaio Malagodi-Braga, Joel Nichols, Anushika L. De Silva, Adalgisa Thayne Munhoz Ramos, Leonardo Massaharu Moriya, Steven M. Ogbourne, David Hawkes, Trent Peters, Naga Kasinadhuni, Shahla Hosseini Bai, Helen M. Wallace and Wiebke Kämper

Horticulturae 2024, 10(3), 203; https://doi.org/10.3390/horticulturae10030203 - 22 Feb 2024

Cited by 2 | Viewed by 1302

Abstract

Global fruit and nut yields are affected by shortfalls in pollinator populations, and pollen limitation is most prevalent among tropical, bee-pollinated and self-incompatible plants. Macadamia is a subtropical, bee-pollinated crop in which some cultivars have been found to be highly outcrossing. We aimed [...] Read more.

Global fruit and nut yields are affected by shortfalls in pollinator populations, and pollen limitation is most prevalent among tropical, bee-pollinated and self-incompatible plants. Macadamia is a subtropical, bee-pollinated crop in which some cultivars have been found to be highly outcrossing. We aimed to determine the extent of outcrossing and its effects on nut quality across a wide range of international macadamia cultivars in three countries. We sampled fruit from 19 macadamia cultivars across 23 sites in Australia, Brazil and South Africa. We used genotype-by-sequencing and MassARRAY methods to assign paternity to individual fruit and we assessed pollen-parent effects on nut quality. Macadamia was highly outcrossing, producing 80–100% of fruit by cross-pollination, at 17 of the 23 sites. Mixed mating (41–72% outcrossing) was identified at five sites, and low outcrossing (10%) was identified in one cultivar at one site where it was isolated from other flowering macadamia trees. Outcrossed fruit often had significantly better quality than selfed fruit, with 1.61–3.39 g higher nut-in-shell mass, 0.53–1.55 g higher kernel mass, 3.3–6.4% higher kernel recovery, and 3.0–3.5% higher oil concentration. The differences in kernel recovery equated to differences in value of USD 433–841 per ton of nut-in-shell at prices of USD 3000 per ton. In summary, macadamia cultivars were mostly highly outcrossing, and outcrossed nuts often had higher quality than selfed nuts. Growers should consider interplanting different cultivars more closely and distributing bee hives more widely to maximise cross-pollination, produce high yields, and optimise nut quality. Full article

(This article belongs to the Special Issue Modern Systems of Fruit Growing and Their Application for the Improvement of Tropical Fruit Products)

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17 pages, 5391 KiB

Open AccessEditor’s ChoiceArticle

Exogenous Abscisic Acid Regulates Anthocyanin Biosynthesis and Gene Expression in Blueberry Leaves

by Bin Ma, Yan Song, Xinghua Feng, Qingxun Guo, Lianxia Zhou, Xinsheng Zhang and Chunyu Zhang

Horticulturae 2024, 10(2), 192; https://doi.org/10.3390/horticulturae10020192 - 19 Feb 2024

Viewed by 1533

Abstract

Blueberry (Vaccinium corymbosum) leaves have a positive influence on health because of their phenolic contents, including anthocyanins. Phytohormone abscisic acid (ABA) promotes anthocyanin accumulation, but the underlying mechanisms are unclear in blueberry leaves. In this study, we found that exogenous ABA [...] Read more.

Blueberry (Vaccinium corymbosum) leaves have a positive influence on health because of their phenolic contents, including anthocyanins. Phytohormone abscisic acid (ABA) promotes anthocyanin accumulation, but the underlying mechanisms are unclear in blueberry leaves. In this study, we found that exogenous ABA promotes anthocyanin accumulation in blueberry leaves and we explored the global molecular events involved in these physiological changes by treating in vitro-grown blueberry seedlings with ABA and performing transcriptome deep sequencing (RNA-seq). We identified 6390 differentially expressed genes (DEGs), with 2893 DEGs at 6 h and 4789 at 12 h of ABA treatment compared to the control. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to plant hormone signal transduction and phenylpropanoid and flavonoid biosynthesis were significantly enriched at both stages of the ABA treatment. Analysis of DEGs in plant hormone signal transduction pathways revealed that exogenous ABA affected the expression of genes from other plant hormone signaling pathways, especially brassinosteroid, auxin, and gibberellin signaling. To elucidate the mechanism driving anthocyanin biosynthesis in blueberry in response to ABA treatment, we screened anthocyanin biosynthesis structural genes (ASG) from the phenylpropanoid and flavonoid biosynthetic pathways, MYB transcription factor genes from R2R3-MYB subgroups 5, 6, and 7 and ABRE-binding factor (ABF) genes from the ABA signal transduction pathway. Pearson’s correlation coefficient (r) analysis indicated that the ABFs, MYBs, and structural genes form a network to regulate ABA-induced anthocyanin biosynthesis and MYBA1 is likely to play an important role in this regulatory network. These findings lay the foundation for improving anthocyanin biosynthesis in blueberry leaves. Full article

(This article belongs to the Special Issue Advances in Developmental Biology in Tree Fruit and Nut Crops)

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13 pages, 938 KiB

Open AccessEditor’s ChoiceArticle

Growing Salicornia europaea L. with Saline Hydroponic or Aquaculture Wastewater

by Martina Puccinelli, Ilaria Marchioni, Luca Botrini, Giulia Carmassi, Alberto Pardossi and Laura Pistelli

Horticulturae 2024, 10(2), 196; https://doi.org/10.3390/horticulturae10020196 - 19 Feb 2024

Cited by 2 | Viewed by 1651

Abstract

Among halophyte plants, Salicornia species (also known as glasswort or sea asparagus) are increasingly grown in open fields and greenhouses for edible or non-edible purposes. Their salinity tolerance makes it possible to irrigate Salicornia plants with saline waters and even seawater, which cannot [...] Read more.

Among halophyte plants, Salicornia species (also known as glasswort or sea asparagus) are increasingly grown in open fields and greenhouses for edible or non-edible purposes. Their salinity tolerance makes it possible to irrigate Salicornia plants with saline waters and even seawater, which cannot be used by other crop species. In this work, S. europaea (L.) was cultivated in pots under the typical climatic conditions of the fall season in the Mediterranean region and irrigated with non-saline standard nutrient solution (SNS) or saline wastewater discharged from a greenhouse semi-closed hydroponic (substrate) culture of tomato or a saltwater recirculating aquaculture system (RAS) with Gilthead sea bream (Spaurus aurata L., which was used as such or after dilution (50:50) with SNS. Plant growth was not significantly affected by the composition of irrigation water, while higher antioxidant capacity (measured using the DPPH assay) and concentration of photosynthetic pigments, phenols, flavonoids, and ascorbic acid were found in the shoots of SNS plants than in those of plants irrigated with wastewater. The level of lipid peroxidation and H₂O₂ production significantly increased in the SNS plants, which also showed higher activity of superoxide dismutase and lower activity of catalase. These results suggest that S. europaea can be cultivated using wastewater with moderate to high salinity discharged from greenhouse hydroponic crops or RASs, and that salt is not strictly required for the growth of this species. Using non-saline nutrient solution can result in moderate oxidative stress that improves the shoot quality of S. europaea. Full article

(This article belongs to the Collection Biosaline Agriculture)

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32 pages, 19325 KiB

Open AccessEditor’s ChoiceArticle

Seedling Growth Stress Quantification Based on Environmental Factors Using Sensor Fusion and Image Processing

by Sumaiya Islam, Md Nasim Reza, Shahriar Ahmed, Samsuzzaman, Yeon Jin Cho, Dong Hee Noh and Sun-Ok Chung

Horticulturae 2024, 10(2), 186; https://doi.org/10.3390/horticulturae10020186 - 18 Feb 2024

Cited by 1 | Viewed by 1416

Abstract

Understanding the diverse environmental influences on seedling growth is critical for maximizing yields. The need for a more comprehensive understanding of how various environmental factors affect seedling growth is required. Integrating sensor data and image processing techniques offers a promising approach to accurately [...] Read more.

Understanding the diverse environmental influences on seedling growth is critical for maximizing yields. The need for a more comprehensive understanding of how various environmental factors affect seedling growth is required. Integrating sensor data and image processing techniques offers a promising approach to accurately detect stress symptoms and uncover hidden patterns, enhancing the comprehension of seedling responses to environmental factors. The objective of this study was to quantify environmental stress symptoms for six seedling varieties using image-extracted feature characteristics. Three sensors were used: an RGB camera for color, shape, and size information; a thermal camera for measuring canopy temperature; and a depth camera for providing seedling height from the image-extracted features. Six seedling varieties were grown under controlled conditions, with variations in temperature, light intensity, nutrients, and water supply, while daily automated imaging was conducted for two weeks. Key seedling features, including leaf area, leaf color, seedling height, and canopy temperature, were derived through image processing techniques. These features were then employed to quantify stress symptoms for each seedling type. The analysis of stress effects on the six seedling varieties revealed distinct responses to environmental stressors. Integration of color, size, and shape parameters established a visual hierarchy: pepper and pak choi seedlings showed a good response, cucumber seedlings showed a milder response, and lettuce and tomato seedlings displayed an intermediate response. Pepper and tomato seedlings exhibited a wide range of growth stress symptoms, at 13.00% to 83.33% and 2.96% to 70.01%, respectively, indicating considerable variability in their reactions to environmental stressors. The suggested classification approach provides valuable groundwork for advancing stress monitoring and enabling growers to optimize environmental conditions. Full article

(This article belongs to the Special Issue Controlled Environment Horticulture: Latest Advances and Future Prospects)

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13 pages, 1193 KiB

Open AccessEditor’s ChoiceArticle

Monofilament Shading Nets Improved Water Use Efficiency on High-Temperature Days in Grapevines Subjected to Hyperarid Conditions

by Gastón Gutiérrez-Gamboa, Emilio Villalobos-Soublett, Marco Garrido-Salinas and Nicolás Verdugo-Vásquez

Horticulturae 2024, 10(2), 176; https://doi.org/10.3390/horticulturae10020176 - 16 Feb 2024

Viewed by 1074

Abstract

(1) Background: Table grapes are often subjected to thermal stress during the growing season, affecting their production. Shading nets utilization has been proposed as an alternative to face this problem, but there is little available information about their effectiveness in hyperarid conditions. INIA-G2 [...] Read more.

(1) Background: Table grapes are often subjected to thermal stress during the growing season, affecting their production. Shading nets utilization has been proposed as an alternative to face this problem, but there is little available information about their effectiveness in hyperarid conditions. INIA-G2 vines were covered with kristall-colored mesh of 8% shade, and their ecophysiological responses were compared to uncovered vines during the daily cycle of two days with contrasting thermic conditions. (2) Methods: Net assimilation rate (A_N), stomatal conductance (g_s), transpiration (E), instantaneous water use efficiency (WUE: A_N E⁻¹), stem water potential (Ψ_s), air temperature (Ta) and vapor-pressure deficit (DPV) were determined in daily cycles (from 06:00 to 20:00 hrs) on two thermally contrasting days (330 DOY at 29.4 °C and 345 DOY at 22.6 °C) on grapevines without water restriction. (3) Results: The Ψ_s was not affected by treatment and day of measurement; nevertheless, A_N and g_s were statistically lower during 330 than 345 DOY (31% and 44% decrease, respectively). The covered vines presented less restrictive climatic conditions in terms of DPV in both DOY, reaching higher WUE values at 10, 12 and 14 h, which was associated with a decrease in E. (4) Conclusions: These results suggest that the use of shading nets can be an interesting alternative to cope with high temperatures in viticulture, improving the water use efficiency of vines. These are the first published results about the viticultural performance of the INIA-G2 variety. Full article

(This article belongs to the Section Viticulture)

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15 pages, 6098 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Comparison of Citrus Leaf Water Content Estimations Based on the Continuous Wavelet Transform and Fractional Derivative Methods

by Shiqing Dou, Wenjie Zhang, Yuanxiang Deng, Chenhong Zhang, Zhengmin Mei, Jichi Yan and Minglan Li

Horticulturae 2024, 10(2), 177; https://doi.org/10.3390/horticulturae10020177 - 16 Feb 2024

Cited by 1 | Viewed by 918

Abstract

Citrus tangerines are famous fruits worldwide, and monitoring the water content of citrus leaves is highly important for citrus production. However, there are still challenges in quantitatively estimating the water content of citrus leaves using hyperspectral technology, and the random noise generated during [...] Read more.

Citrus tangerines are famous fruits worldwide, and monitoring the water content of citrus leaves is highly important for citrus production. However, there are still challenges in quantitatively estimating the water content of citrus leaves using hyperspectral technology, and the random noise generated during spectral acquisition and the overlapping peaks in the sensitive band of the citrus leaf water content will affect estimation accuracy. To solve these problems and further explore the roles of the continuous wavelet transform (CWT) and fractional-order derivative (FOD) in the estimation of citrus leaf water content, this study intends to use of CWT and FOD to decompose the original spectrum, and then compare the correlation between the original spectrum and leaf water content to explore whether the decomposition treatment has improved the correlation between spectrum and leaf moisture content. Then, the successive projections algorithm (SPA) was used to select feature bands and combine spectral vegetation indices. Partial least squares regression (PLSR) was used to construct water-content inversion models for citrus leaves, and the inversion accuracies of two commonly used spectral preprocessing methods were compared. The results indicate that (1) the CWT can improve the sensitivity of the spectrum to the citrus leaf water content to a certain extent, and the inversion accuracy of the CWT is approximately 5% greater than that of the FOD. (2) On the basis of the CWT and FOD methods, the inversion accuracy of the citrus leaf water content based on SPA screening increased by 9.61% and 9.29%, respectively, compared with the original spectrum. (3) Under CWT decomposition, Scale4 of the Gaus1 wavelet was screened by the SPA, and the inversion model of citrus leaf water content was constructed by combining the spectral vegetation index NDVI with the best results. The R-squared (

R^{2}

) and root mean square error (RMSE) values were 0.7491 and 0.0284, respectively, which were both 0.0138 greater than those of the best inversion model for the FOD

R^{2}

. In conclusion, the CWT-SPA combined with the spectral vegetation index can improve the sensitivity of the spectrum to the citrus leaf water content, eliminate a large amount of redundant data, and enhance the prediction ability and stability of the citrus leaf water content. Full article

(This article belongs to the Special Issue An Update of the Crop Management Practices Enhancing Yield and Quality in Citrus)

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17 pages, 1808 KiB

Open AccessEditor’s ChoiceArticle

Egyptian Citrus Essential Oils Recovered from Lemon, Orange, and Mandarin Peels: Phytochemical and Biological Value

by Faten Mohamed Ibrahim, Reda Sayed Mohammed, Eman Abdelsalam, Wedian El-Sayed Ashour, Daniela Magalhães, Manuela Pintado and El Sayed El Habbasha

Horticulturae 2024, 10(2), 180; https://doi.org/10.3390/horticulturae10020180 - 16 Feb 2024

Cited by 2 | Viewed by 1980

Abstract

Citrus peels are an important by-product of citrus processing industries, but a large part is considered waste. There has been increased attention in the last five years on these industrial by-products, especially those containing residual essential oils (EOs). Lemon, orange, and mandarin peels [...] Read more.

Citrus peels are an important by-product of citrus processing industries, but a large part is considered waste. There has been increased attention in the last five years on these industrial by-products, especially those containing residual essential oils (EOs). Lemon, orange, and mandarin peels from Egypt were subjected to hydro-distillation to obtain EOs, which were analyzed via mass spectrometry (GC/MS) and by building Global Natural Products Social Molecular Networking (GNPS-MN) for the purpose of visually exploring the volatile components of citrus species. The constructed MN revealed that D-Limonene, α-pinene, and β-pinene are the dominant volatile constituents in the three Egyptian citrus species. The EOs from three citrus peels exhibited promising activities as antioxidants using two tested methods: 1,1-diphenyl-2-picryl-hydrazil (DPPH) and nitric oxide (NO) compared with vitamin C. Lemon EO proved excellent antimicrobial activity against Gram-positive and negative bacteria. Additionally, the three citrus EOs showed good activities against the yeast Candida albicans. Regarding the anti-inflammatory assay, the three citrus EOs showed promising activities as COX-1 and COX-2 inhibitors. This study concludes that EOs extracted from citrus peel waste can be valorized as an innovative strategy for food preservation or may be incorporated in cosmetics and pharmaceutical formulations in alignment with circular economy principles. Full article

(This article belongs to the Special Issue Medicinal and Aromatic Plants: Isolation, Characterization and Biological Activities)

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15 pages, 1687 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Enhancing the Yield of Mature Olive Trees via Comparative Fertilization Strategies, including a Foliar Application with Fulvic and Humic Acids, in Non-Irrigated Orchards with Calcareous and Non-Calcareous Soils

by Stavros Sotiropoulos, Christos Chatzissavvidis, Ioannis E. Papadakis, Victor Kavvadias, Christos Paschalidis, Chrysovalantou Antonopoulou and Sotirios Kiriakopoulos

Horticulturae 2024, 10(2), 167; https://doi.org/10.3390/horticulturae10020167 - 12 Feb 2024

Viewed by 1811

Abstract

This study investigated the impact of fertilization treatments on mature, forty-year-old, fully productive olive trees (Olea europaea L. cv. Koroneiki) in two non-irrigated orchards featuring contrasting soil types: non-calcareous–acidic and calcareous–alkaline. Over three years (2019–2021), seven distinct treatments were applied, involving inorganic [...] Read more.

This study investigated the impact of fertilization treatments on mature, forty-year-old, fully productive olive trees (Olea europaea L. cv. Koroneiki) in two non-irrigated orchards featuring contrasting soil types: non-calcareous–acidic and calcareous–alkaline. Over three years (2019–2021), seven distinct treatments were applied, involving inorganic soil fertilizers (traditional strategy) and foliar applications of a liquid organic product containing fulvic and humic acids. Fertilization significantly influenced physiological parameters, such as mineral nutrition, photosynthetic pigments of olive leaves, fruit yield, and oil production per tree, revealing noteworthy effects influenced by soil types and their interactions with treatments. Statistical analysis highlighted specific treatments, indicating that the foliar application of the organic product once a year in alkaline soil or biannually in acidic soil resulted in the highest observed fruit yield and oil production per tree. Indeed, contrary to the control–unfertilized trees, specific fertilization strategies resulted in an average increase of up to 47% and 73% in fruit yield per tree and up to 96% and 100% in oil production per tree in acidic and alkaline soil, respectively. Furthermore, consistently high yields were correlated with constant high values of the chlorophyll a/chlorophyll b ratio (2.3–3.3 in August for acidic soil) and leaf chlorophyll a concentration (55–66 mg/100 g f.w. in August for alkaline soil). This novel finding underscores the crucial role of these factors as prerequisites for achieving superior fruit production. Our results emphasize the potential of integrating foliar organic fertilization as a complementary strategy to traditional soil-based approaches. This is particularly relevant under non-irrigated/rainfed cultural conditions, emphasizing the significance of considering alternative fertilization practices for optimized olive orchard management. Full article

(This article belongs to the Section Fruit Production Systems)

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23 pages, 10059 KiB

Open AccessEditor’s ChoiceArticle

Biological Control and Cross Infections of the Neofusicoccum spp. Causing Mango Postharvest Rots in Spain

by Lucía Guirado-Manzano, Sandra Tienda, José Antonio Gutiérrez-Barranquero, Antonio de Vicente, Francisco M. Cazorla and Eva Arrebola

Horticulturae 2024, 10(2), 166; https://doi.org/10.3390/horticulturae10020166 - 11 Feb 2024

Viewed by 1409

Abstract

Mango is one of the main subtropical crops growing in southern Spain. Spanish mango fruit production can be efficiently transported to the rest of Europe, and these mangoes are very appreciated for their quality and flavour. However, postharvest rots have been detected in [...] Read more.

Mango is one of the main subtropical crops growing in southern Spain. Spanish mango fruit production can be efficiently transported to the rest of Europe, and these mangoes are very appreciated for their quality and flavour. However, postharvest rots have been detected in stored mango fruits, making their commercialization difficult. The causal agents associated with such rot symptoms have been isolated and identified. Because the mango crops used to share the same growing area with avocado crops, fungal presence on surrounding asymptomatic avocado fruits was also analysed to detect potential cross infections. Artificial inoculation with Neofusicoccum parvum and N. mediterraneum was able to reproduce rot symptoms in mango but was also able to induce rots in avocado fruits. To approach a biological control strategy against these rot-producing fungi, two very well-known antagonistic biocontrol bacteria, Pseudomonas chlororaphis PCL1606, and Bacillus velezensis UMAF6639, were tested. The obtained results revealed that both bacteria can control the fungal rots on stored mango and avocado fruits under controlled conditions. Additionally, the strain B. velezensis UMAF6639 showed the ability to persist on the fruit surface of adult commercial trees in experiments under open field conditions, helping to prevent the appearance of these postharvest diseases. Full article

(This article belongs to the Special Issue Fungal Diseases and Pathogens Affecting Horticultural Crops: New Challenges)

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12 pages, 2915 KiB

Open AccessEditor’s ChoiceArticle

Temporary Immersion System as an Innovative Approach for In Vitro Propagation of Sorbus domestica L.

by Valeria Gianguzzi and Francesco Sottile

Horticulturae 2024, 10(2), 164; https://doi.org/10.3390/horticulturae10020164 - 10 Feb 2024

Cited by 2 | Viewed by 1523

Abstract

The genus Sorbus has maintained an extremely relevant role over time from a landscape and environmental perspective in many countries in the Mediterranean and Central Europe. Based on the requirements coming from the environmental policies provided in the European strategy Next Generation EU, [...] Read more.

The genus Sorbus has maintained an extremely relevant role over time from a landscape and environmental perspective in many countries in the Mediterranean and Central Europe. Based on the requirements coming from the environmental policies provided in the European strategy Next Generation EU, Sorbus has been considered a valuable species to be introduced in urban and peri-urban areas. The purpose of this study was to propagate four Sorbus accessions selected in the Sicilian territory, Southern Italy, using the liquid substrate in temporary immersion bioreactors Plantform™. The results obtained showed that the presence of 1 mg L⁻¹ mT in the substrate in combination with IBA 0.05 mg L⁻¹ produced a significant number of shoots (4.7) and a greater length (2.2 cm). Among the accessions, there were statistically significant differences; the accession SN2 and SN1 produced more shoots (respectively, 4.0 and 3.6), and a greater length of the shoots was observed in the selections SN4 and SN3 (respectively, 2.4 cm and 2.3 cm). The relative growth rate (RGR) was significantly influenced by the presence of the culture substrate of the combination of cytokines and auxin; SN4 selection showed the best RGR results of 8.3 mg⁻¹ d⁻¹. The use of the bioreactor Plantform™ in Sorbus domestica L. has favored a better development of plants obtained in vitro, demonstrating that this system is a valid alternative for the micropropagation of Sorbus. Full article

(This article belongs to the Section Propagation and Seeds)

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18 pages, 11766 KiB

Open AccessEditor’s ChoiceArticle

Characterization of Changes in Active Ingredients and Mining of Key Metabolites in Bletilla striata under Shading and Drought Stresses

by Ruoyong Yin, Leiru Chen, Pengfei Deng, Xiaoqing Cao and Xiaoniu Xu

Horticulturae 2024, 10(2), 163; https://doi.org/10.3390/horticulturae10020163 - 10 Feb 2024

Cited by 1 | Viewed by 1181

Abstract

Shading and drought are considered crucial abiotic stress factors that limit the normal growth of plants. Under natural conditions, the quality of Bletilla striata pseudobulbs (BP), a Chinese traditional medicinal crop, is often affected by the dual stresses of shading and drought. However, [...] Read more.

Shading and drought are considered crucial abiotic stress factors that limit the normal growth of plants. Under natural conditions, the quality of Bletilla striata pseudobulbs (BP), a Chinese traditional medicinal crop, is often affected by the dual stresses of shading and drought. However, the relationship and mechanism of the interaction between the two stress factors in B. striata remain unclear. In this study, we examined the changes in photosynthetic properties and active ingredients of B. striata under shading (L), drought (W), and shading-drought dual stresses (LW). We aimed to explore the metabolite mechanism that led to these changes using GC-MS-based non-targeted metabolomics techniques. The results indicated a significant reduction in the polysaccharide content of BP under W and LW treatments compared to the control (CK). The total phenol content was significantly reduced under L treatment, while the total flavonoid content did not change significantly under the three stresses. The significant increase in militarine content under all three stresses implies that B. striata may modulate its biosynthesis in response to different environmental stresses. Transpiration rate and stomatal conductance were reduced, amino acid expression was up-regulated, and carbohydrate expression was down-regulated in B. striata under L treatment. The net photosynthesis rate, stomatal conductance, and transpiration rate exhibited significant reductions, and the tuber metabolic disorder marker Homocysteine increased and organic acid content as well under W treatment. The net photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency of B. striata were further reduced under LW compared with single stress, which is in agreement with the “trade-off theory”. Pseudobulb metabolite changes, in combination with the results of the two single stresses, showed an up-regulation of amino acids and disaccharide compounds and a down-regulation of monosaccharide compounds. A support vector machine model (SVM) was used to screen 10 marker metabolites and accurately predict the changes in active ingredient content through an artificial neural network model (ANN). The results suggest that an appropriate stress environment can enhance the content of the target active ingredients based on cultivation goals. Full article

(This article belongs to the Special Issue Plants Response to Abiotic Stresses: Strategies for Adaptations and Survival)

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21 pages, 7059 KiB

Open AccessEditor’s ChoiceArticle

Optimized Fertilizer–Water Management Improves Carrot Quality and Soil Nutrition and Reduces Greenhouse Gas Emissions on the North China Plain

by Wenhui Tang, Cuiyue Zhang, Peiqiang Zhang, Ying Zhao, Mengyao Guo, Yun Li, Ruiping Chi and Yanling Chen

Horticulturae 2024, 10(2), 151; https://doi.org/10.3390/horticulturae10020151 - 6 Feb 2024

Viewed by 1308

Abstract

In order to improve carrot quality and soil nutrition and reduce the environmental pollution caused by intensive carrot production, more comprehensive combined water–fertilizer management strategies are necessary. This study hypothesizes that optimal management of water and fertilizer can improve carrot yield and quality [...] Read more.

In order to improve carrot quality and soil nutrition and reduce the environmental pollution caused by intensive carrot production, more comprehensive combined water–fertilizer management strategies are necessary. This study hypothesizes that optimal management of water and fertilizer can improve carrot yield and quality and reduce greenhouse gas emissions and soil nutrient residues. Thus, coordinated water–fertilizer management strategies were tested for carrot production on the North China Plain over two consecutive growing seasons. Four treatments were tested: local standard fertilization and irrigation practices (FNP); optimized irrigation and chemical nitrogen, phosphorus, and potassium fertilizer (OPT); OPT treatment with partial replacement of chemical fertilizer with peanut shell (PS); and OPT treatment with partial replacement of chemical fertilizer with mushroom residue (M). Compared to the FNP treatment, there were statistically significant increases in soluble sugars (12–27%) and free amino acids (14–26%), and decreases in the nitrate content (7–17%) of fleshy root in the OPT, PS, and M treatments. In autumn carrots, the OPT and M treatments decreased yield, whereas PS increased yield; spring carrot yield was significantly decreased in the OPT, PS, and M groups compared to the FNP group. There were no significant effects of the treatment group on carrot growth rates, nutrient accumulation, or nutrient distribution. However, the OPT, PS, and M treatments were associated with significantly increased partial productivity of phosphate fertilizer (233–363%), reduced residual levels of nitrate and available phosphorus in the top 80 cm of soil, and decreased greenhouse gas emissions by 8–18% compared to the FNP treatment. These results highlight the effectiveness of partial organic fertilizer substitution and integrated water–fertilizer management to produce high-quality carrots with minimal environmental damage. Full article

(This article belongs to the Section Plant Nutrition)

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23 pages, 3012 KiB

Open AccessEditor’s ChoiceArticle

Variations in Essential Oil Composition and Chemotype Patterns of Wild Thyme (Thymus) Species in the Natural Habitats of Hungary

by Zsuzsanna Pluhár, Róbert Kun, Judit Cservenka, Éva Neumayer, Szilvia Tavaszi-Sárosi, Péter Radácsi and Beáta Gosztola

Horticulturae 2024, 10(2), 150; https://doi.org/10.3390/horticulturae10020150 - 5 Feb 2024

Cited by 1 | Viewed by 1349

Abstract

A comprehensive study was conducted on the diversity and characteristics of five Thymus species native to Hungary, concerning frequency of occurrence, habitat preferences, essential oil content of the dried flowering shoots, and chemotype patterns determined by GC/MS. Our main aims were to provide [...] Read more.

A comprehensive study was conducted on the diversity and characteristics of five Thymus species native to Hungary, concerning frequency of occurrence, habitat preferences, essential oil content of the dried flowering shoots, and chemotype patterns determined by GC/MS. Our main aims were to provide an overview of the essential oil diversity of thyme resources and select the best genotypes with potential for cultivation and utilization. Based on the results obtained in 74 populations of 63 localities belonging to 15 regions of the Transdanubian and Northern Hungarian Mountains, considerable essential oil diversity was found. Thymus pannonicus (TPA), of generalist character, was proven to be the most frequent species (38 populations), while T. serpyllum (TSE) occurred only in two habitats. High average amounts of essential oil (EO) were shown for T. pannonicus (0.46 mL/100 g DW), T. pulegioides (TPU: 0.47 mL/100 g DW), and T. serpyllum (0.59 mL/100 g DW), while low EO accumulating ability was detected in T. glabrescens (TGL: 0.26 mL/100 g DW) and in T. praecox (TPR: 0.10 mL/100 g DW). In general, the thymol chemotype was the most frequent (34 populations), found together with the related molecules (p-cymene: 26; γ-terpinene: 15), while numerous other monoterpenes (M: geraniol: 12, linalool: 7) or sesquiterpenes (S: germacrene D: 25, β-caryophyllene: 21) were dominant, as well as combined (MS) chemotypes, which were also described in the Eos of Thymus species in Hungary. Our findings confirmed that T. pannonicus shows potential for cultivation with homogenous drug quality, adequate amounts of essential oil, and stability in EO composition. Data from original habitats also supports its high tolerance and adaptability to diverse environmental conditions, which is advantageous when facing climate change and extremities. Full article

(This article belongs to the Special Issue Exploration of Medicinal Plants: Recent Advances and Future Perspectives)

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12 pages, 507 KiB

Open AccessEditor’s ChoiceArticle

The Use of Cubic Smoothing Spline Models for Predicting Early Fruit Size in ‘Keenan’ Valencia (Citrus sinensis L. Osbeck) Oranges

by Tahir Khurshid, Ben Braysher and Jane Elizabeth Khurshid

Horticulturae 2024, 10(2), 149; https://doi.org/10.3390/horticulturae10020149 - 5 Feb 2024

Viewed by 1057

Abstract

Fruit size is an important factor for the sale of fruit in fresh markets. Fruit size prediction early in the growing season would help with planning harvest operations, administering marketing strategies and an advance determination of the proportion of fruit that will be [...] Read more.

Fruit size is an important factor for the sale of fruit in fresh markets. Fruit size prediction early in the growing season would help with planning harvest operations, administering marketing strategies and an advance determination of the proportion of fruit that will be suitable for certain size classes. Fruit diameter growth of ‘Keenan’ Valencia oranges was measured over five consecutive growing seasons (2014–2018) during Stage II (cell enlargement) and Stage III (maturation) periods between January and October. Fruits were randomly selected and tagged from around the tree canopy to record the fruit diameter at fortnightly intervals until harvest. The data were used to develop a fruit size prediction model using the cubic smoothing splines technique. Results indicated that from the fruit growth patterns, an accurate prediction of the final fruit size and distribution were possible during the early Stage II fruit development phase, 6–7 months ahead of the final harvest. It was concluded that fruit size must be 66 mm in diameter by 30 March to attain a fruit size > 77 mm at harvest. This model was tested in 2019 with an accuracy of 97% in predicting fruit size distribution harvest across three size classes. Full article

(This article belongs to the Special Issue An Update of the Crop Management Practices Enhancing Yield and Quality in Citrus)

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17 pages, 2027 KiB

Open AccessEditor’s ChoiceArticle

Inadequate Pollination Is a Key Factor Determining Low Fruit-to-Flower Ratios in Avocado

by María L. Alcaraz and Jose I. Hormaza

Horticulturae 2024, 10(2), 140; https://doi.org/10.3390/horticulturae10020140 - 31 Jan 2024

Cited by 1 | Viewed by 1154

Abstract

Avocado is an evergreen tree that exhibits protogynous dichogamy and displays a massive flower production, characterized by a high abscission of unfertilized flowers and developing fruitlets, ultimately leading to a low final fruit set. A common practice to improve avocado pollination involves introducing [...] Read more.

Avocado is an evergreen tree that exhibits protogynous dichogamy and displays a massive flower production, characterized by a high abscission of unfertilized flowers and developing fruitlets, ultimately leading to a low final fruit set. A common practice to improve avocado pollination involves introducing honey bee (Apis mellifera L.) hives during the flowering season. To evaluate the extent of inadequate pollination in avocado, the effect of different beehive densities on the percentage of flowers receiving pollen during the female flower stage was examined for seven years in an experimental orchard located in Southern Spain. A total of 17,288 flowers were observed under the microscope for this purpose. Additionally, pollen deposition was evaluated in five “Hass” avocado commercial orchards under different management strategies situated in the Malaga province (3960 flowers). The results obtained reveal that the percentage of flowers with pollen at the end of the female stage ranged from 2.85 (0.13% fruits retained at the end of June) in orchards without honey bee hives to 4.34 (0.11% fruits retained) in orchards in which 10 beehives per ha were placed. This percentage increased significantly to 13.79 after introducing 24 honey beehives per ha (0.21% fruits retained). Furthermore, the percentage of pollinated flowers in the commercial orchards remained below 15% even in those orchards in which pollen donors and honey bee hives were present. Thus, insufficient pollination could be considered as a primary limiting factor in avocado production under Mediterranean climates. Enhancing pollinator diversity and increasing their numbers could be a viable strategy to improve the percentage of avocado flowers receiving pollen during the female stage. Full article

(This article belongs to the Section Fruit Production Systems)

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26 pages, 1685 KiB

Open AccessEditor’s ChoiceArticle

Changes in Secondary Metabolite Production in Response to Salt Stress in Alcea rosea L.

by Arezoo Sadeghi, Jamshid Razmjoo, Hassan Karimmojeni, Timothy C. Baldwin and Andrea Mastinu

Horticulturae 2024, 10(2), 139; https://doi.org/10.3390/horticulturae10020139 - 31 Jan 2024

Cited by 3 | Viewed by 1256

Abstract

The effect of three levels of salinity on physio-biochemical traits in 10 Alcea rosea (hollyhock) varieties were evaluated. It was observed that salt stress increased both the total phenolic content (TPC) and total flavonoid content (TFC) in some varieties and decreased them in [...] Read more.

The effect of three levels of salinity on physio-biochemical traits in 10 Alcea rosea (hollyhock) varieties were evaluated. It was observed that salt stress increased both the total phenolic content (TPC) and total flavonoid content (TFC) in some varieties and decreased them in others. The greatest increases in both TPC and TFC were recorded in the Saman variety (104% and 62%, respectively) when cultivated under severe salt stress, indicating that this is the most salt-tolerant variety amongst those tested. The most abundant phenolic compound recorded was ellagic acid, and the phenolic compounds that showed the greatest increases in concentration due to salt stress were p-coumaric acid (87% in the Isfahan variety) and chlorogenic acid (142% in the Mahallat variety). Salt stress was also shown to decrease the production of diphenyl-2-picrylhydrazyl (DPPH) in all varieties. The highest concentration of DPPH (133%) was recorded in the Shiraz 1 variety, grown under conditions of severe salt stress. Salt stress also increased the mucilage content present in the petals, leaves, and seeds of some of the selected varieties. These data suggest that the selection of salt-tolerant varieties of hollyhock for direct cultivation or for use in future breeding programs is feasible. Full article

(This article belongs to the Section Biotic and Abiotic Stress)

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14 pages, 1802 KiB

Open AccessEditor’s ChoiceArticle

Role of Two Transcription Factors (TGA 1a and TGA 2.1) in the Mi-1-Mediated Resistance of Tomato to the Root-Knot Nematode Meloidogyne javanica

by Susana Pascual, Mariana Emiliozzi and Gloria Nombela

Horticulturae 2024, 10(2), 134; https://doi.org/10.3390/horticulturae10020134 - 30 Jan 2024

Viewed by 1215

Abstract

The Mi-1 gene in tomato confers resistance against insects and nematodes. The mechanisms involved in the functioning of this gene are not completely known, and they differ depending on the damaging organism (insect or nematode). Transcription factors (TF) from different families are essential [...] Read more.

The Mi-1 gene in tomato confers resistance against insects and nematodes. The mechanisms involved in the functioning of this gene are not completely known, and they differ depending on the damaging organism (insect or nematode). Transcription factors (TF) from different families are essential for plant defence, and the TGAs, members of the Basic Leucine Zipper (bZIP) TF family, are relevant in different pathosystems. In this work, the implication of TGA 1a and TGA 2.1 genes in Mi-1 resistance against the root-knot nematode Meloidogyne javanica was studied, by virus-induced gene silencing (VIGS) based on Tobacco rattle virus (TRV). Results showed that infiltration with the empty TRV vector did not alter Mi-1-mediated resistance, confirming the adequacy of this method. Silencing of the TGA 1a gene resulted in a decrease in resistance to M. javanica, as the numbers of egg masses were significantly higher than those on non-silenced plants. This decrease in resistance was similar to that caused by silencing the Mi-1 gene. However, the silencing of the TGA 2.1 gene caused a limited loss of resistance, with infestation levels intermediate between those of resistant and susceptible varieties. Thus, our results demonstrate the requirement of TGA 1a in Mi-1-mediated resistance to M. javanica, while the incomplete silencing of TGA 2.1 impaired a specific determination of its role. Full article

(This article belongs to the Special Issue Plant-Parasitic Nematodes in Horticultural Crops)

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16 pages, 3959 KiB

Open AccessEditor’s ChoiceArticle

Developing EST-SSR Markers for Identifying and Evaluating Asparagus Germplasm Resources Based on Transcriptome Sequences

by Dan Liu, Feili Yan, Changmei Liu, Aimeng Chen, Jiahui Wu, Ma Yu and Xiangyang Lyu

Horticulturae 2024, 10(2), 121; https://doi.org/10.3390/horticulturae10020121 - 26 Jan 2024

Cited by 1 | Viewed by 1075

Abstract

Radix asparagi is the dried root tuber of the Liliaceae plant Asparagus cochinchinensis (Lour.) Merr., which is a major Chinese medicinal herb with high medicinal and edible value in China. The planting area of A. cochinchinensis is extensive, and there is blind introduction [...] Read more.

Radix asparagi is the dried root tuber of the Liliaceae plant Asparagus cochinchinensis (Lour.) Merr., which is a major Chinese medicinal herb with high medicinal and edible value in China. The planting area of A. cochinchinensis is extensive, and there is blind introduction in various regions, leading to confusion the origin of Radix asparagi and impure germplasm. This study conducted morphological and karyotype analyses on cultivated Asparagus resources from seven main production areas in China and developed SSR molecular markers suitable for the identification of Asparagus germplasm resources based on the transcriptome sequencing results. The morphological results indicate that in addition to A. cochinchinensis (Lour.) Merr., recorded in the Pharmacopoeia of the People’s Republic of China, there are also A. taliensis Wang et Tang and A. lycopodineus (Baker) Wang et Tang cultivated in China. All the tested Asparagus resources were diploid and had 20 chromosomes. A total of 8841 single genes containing SSR loci were identified using transcriptome sequencing of Neijiang Asparagus, including 761 SSR loci with trinucleotide repeat units. One hundred pairs of SSR primers were randomly designed from the trinucleotide repeat loci for PCR and polymorphism verification, and ten pairs were selected for identification of Asparagus germplasm resources. The genetic diversity results of ten pairs of primers in seven Asparagus-producing regions were consistent with the morphological identification. This study provides technical support for the comprehensive evaluation and utilization of Asparagus germplasm resources. Full article

(This article belongs to the Special Issue Breeding, Cultivation, and Metabolic Regulation of Medicinal Plants)

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21 pages, 3125 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Predictive Model to Evaluate Water and Nutrient Uptake in Vertically Grown Lettuce under Mediterranean Greenhouse Conditions

by Manuel Felipe López Mora, María Fernanda Quintero Castellanos, Carlos Alberto González Murillo, Calina Borgovan, María del Carmen Salas Sanjuan and Miguel Guzmán

Horticulturae 2024, 10(2), 117; https://doi.org/10.3390/horticulturae10020117 - 25 Jan 2024

Cited by 1 | Viewed by 1654

Abstract

The decrease in arable land, water scarcity, and climate change increase the pressure on natural resources and agricultural production systems. In this context, agriculture must ensure food production for the rapidly growing and increasingly urban population of the world. Efforts must be made [...] Read more.

The decrease in arable land, water scarcity, and climate change increase the pressure on natural resources and agricultural production systems. In this context, agriculture must ensure food production for the rapidly growing and increasingly urban population of the world. Efforts must be made to obtain the highest yield from the unit area and promote the transition to more sustainable production systems Hydroponics is a modern growing technology mainly applied in greenhouses, which has developed rapidly over the past 30–40 years. Substrate-free hydroponic vertical crops (VC) can reduce the pressure conventional agriculture exerts on resources, saving water and nutrients, and increasing crop yields per unit area. Therefore, this study aimed to validate a proposed predictive model (PM) to simulate water and nutrient uptake in vertical crops under greenhouse conditions. On the basis of the Penman–Monteith equation, the PM estimates transpiration, while nutrient uptake was estimated using the Carmassi–Sonneveld submodel. The PM was experimentally evaluated for vertically grown lettuce under Mediterranean greenhouse conditions during spring 2023. The irrigation technique was a closed-loop fertigation circuit. The experiment consisted of testing two densities (50 and 80 plants·m⁻²) and three plant positions (low, medium, and upper). ANOVA (p < 0.05) and R² were used to evaluate the PM performance and crop behavior. The low density and the upper position had significantly higher mass values. The results suggest a high degree of performance for the PM, as the R² ranged from 0.7 to 0.9 for water and nutrient uptake. Both densities had a yield 17–20 times higher than conventional lettuce production and significant savings in water, about 85–88%. In this sense, the PM has great potential to intelligently manage VC fertigation, saving water and nutrients, which represents an advance toward reaching SDG 6 and SDG 12 within the 2030 Agenda. Full article

(This article belongs to the Special Issue Water and Fertilizer Management and Sustainable Use in Horticultural Production)

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