Horticulturae

26 pages, 2642 KB

Open AccessArticle

Potassium Silicate Partially Alleviates Salt-Induced Inhibition of Growth, Photosynthetic Performance, PSII Energy Partitioning, and Oxidative Injury in Cucumber Seedlings

by Jun Dong, Jinbo Li, Jinlong Li, Zimo Zhang, Nan Xu, Haixiu Zhong and Lijun Zhou

Horticulturae 2026, 12(9), 1138; https://doi.org/10.3390/horticulturae12091138 - 7 Sep 2026

Abstract

Salt stress restricts cucumber seedling establishment by impairing root development, photosynthesis, ion homeostasis, and redox balance. This study examined whether potassium silicate (K₂SiO₃) could partially alleviate these responses under hydroponic sodium chloride (NaCl) stress. Cucumber seedlings were exposed to [...] Read more.

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

(This article belongs to the Special Issue Response of Horticultural Crops to Abiotic Stress)

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24 pages, 6930 KB

Open AccessArticle

MHF-YOLO: An Improved YOLOv8n-Based Approach Developed for Commercial-Grade Honeysuckle Recognition

by Xinting Ding, Yumian Cui, Hao Li and Zhanhua Song

Horticulturae 2026, 12(9), 1137; https://doi.org/10.3390/horticulturae12091137 - 7 Sep 2026

Abstract

Honeysuckle (Lonicera japonica Thunb.) is a medicinal and edible plant whose flower buds are widely used in functional foods, herbal beverages, and natural antioxidant products. Accurate identification of harvestable buds is important because flower developmental stage affects the accumulation of bioactive constituents [...] Read more.

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

(This article belongs to the Special Issue Emerging Technologies in Smart Agriculture)

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25 pages, 11350 KB

Open AccessArticle

Jasmonic Acid and Salicylic Acid Pretreatment Differentially Modulates Photosynthesis-Related Transcription, Redox Homeostasis, and Defense Gene Expression in Mulberry Against Glyphodes pyloalis

by Sheraz Ahmad, Rahat Sharif, Xiaotong Feng, Peng Zeng, Kang Li, Jiping Liu and Ling Tian

Horticulturae 2026, 12(9), 1136; https://doi.org/10.3390/horticulturae12091136 - 7 Sep 2026

Abstract

Glyphodes pyloalis Walker is a devastating phytophagous pest of mulberry (Morus spp.) that severely compromises leaf yield and quality, thereby threatening sericultural productivity. Although jasmonic acid (JA) and salicylic acid (SA) are well-established regulators of plant antiherbivore defenses, their specific roles in [...] Read more.

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

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

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16 pages, 2387 KB

Open AccessArticle

Evaluation of Ornamental Traits and Their Associations with Genomic Simple Sequence Repeat Markers in Globba sherwoodiana

by Jiayang Chen, Peixun Chen, Jianjun Tan, Yiwei Zhou, Lishan Huang, Tangchun Zheng and Yuanjun Ye

Horticulturae 2026, 12(9), 1135; https://doi.org/10.3390/horticulturae12091135 - 7 Sep 2026

Abstract

Globba spp. is a perennial herbaceous plant of the Zingiberaceae family, characterized by its unique floral architecture and diverse coloration with high ornamental and medicinal value. However, research on the genetic basis of Globba is still insufficient, and only a limited number of [...] Read more.

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

(This article belongs to the Topic Genetic Breeding and Biotechnology of Garden Plants)

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26 pages, 2764 KB

Open AccessArticle

Effects of Individual and Consortium Inoculation of Bacillus velezensis, Burkholderia pyrrocinia, and Streptomyces sp. on Acclimatization and Tuberization of Micropropagated Potato

by El Hadi Erbiai, Fidel Carlos Jaime, Fernanda Leal and Guilhermina Marques

Horticulturae 2026, 12(9), 1134; https://doi.org/10.3390/horticulturae12091134 - 7 Sep 2026

Abstract

Potato (Solanum tuberosum L.), the third most important food crop worldwide, is constrained by phytopathogens, environmental stress, and heavy agrochemical use. Potato micropropagation is a biotechnological strategy for producing genetically uniform, pathogen-free plantlets. However, the acclimatization phase remains a major bottleneck in [...] Read more.

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

(This article belongs to the Special Issue Strategies of Producing Horticultural Crops Under Climate Change)

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30 pages, 2990 KB

Open AccessArticle

Production System Influences Postharvest Physiology and Phytonutritional Quality of Cauliflower Cultivars During Refrigerated Storage

by Onakho Manciya, Beverly M. Mampholo, Semkaleng Mpai and Dharini Sivakumar

Horticulturae 2026, 12(9), 1133; https://doi.org/10.3390/horticulturae12091133 - 7 Sep 2026

Abstract

Despite the increasing adoption of soilless cultivation systems, little is known about how the gravel flow technique (GFT) influences postharvest quality, phytonutritional composition, and shelf life of cauliflower compared with conventional soil cultivation, and how these effects interact with cultivar genotype. Therefore, this [...] Read more.

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

(This article belongs to the Special Issue Production, Cultivation, and Breeding of Brassicaceae Crops)

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22 pages, 5582 KB

Open AccessArticle

Evaluation and Refinement of Chinese DUS Test Guidelines Based on Comprehensive Phenotypic Traits: A Case Study of Hawthorn (Crataegus spp.)

by Suliya Ma, Yuanyuan Zhao, Xiao Zhang, Wenxuan Dong and Yuexue Liu

Horticulturae 2026, 12(9), 1132; https://doi.org/10.3390/horticulturae12091132 - 7 Sep 2026

Abstract

Hawthorn (Crataegus spp.), a horticultural crop with significant edible, medicinal, and ornamental values, has garnered increasing attention from breeders to markets, leading to continuous emergence of new varieties. Accurate phenotypic characterization and robust Distinctness, Uniformity, and Stability (DUS) testing are fundamental for [...] Read more.

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

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

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27 pages, 12350 KB

Open AccessFeature PaperArticle

From Genebank to Field: Exploiting Italian Pepper Landraces for Breeding Through Genomic and Phenotypic Characterization

by Ezio Portis, Anna Maria Milani, Elsa Martini, Giuseppe Caputo, Matteo Martina and Cinzia Comino

Horticulturae 2026, 12(9), 1131; https://doi.org/10.3390/horticulturae12091131 - 7 Sep 2026

Abstract

Italian sweet pepper landraces represent an important reservoir of genetic diversity, although their practical exploitation in breeding programmes remains limited. Historical germplasm collections preserve variation accumulated through centuries of farmer selection, but their organization into resources suitable for pre-breeding and parental selection has [...] Read more.

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

(This article belongs to the Special Issue Genetic Breeding and Quality Improvement of Vegetable Crops)

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17 pages, 2316 KB

Open AccessArticle

A Novel Gene IrXyn01 Coding β-Xylanase Is Essential for Ilyonectria robusta Pathogenicity in Early Ginseng Infection

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

Horticulturae 2026, 12(9), 1130; https://doi.org/10.3390/horticulturae12091130 - 7 Sep 2026

Abstract

Ginseng (Panax ginseng), a traditional and valuable medicinal plant, is severely affected by rusty root rot caused by Ilyonectria robusta. Xylanase is hypothesized to play a key role in the pathogenicity of I. robusta. Through transcriptomic analysis during ginseng [...] Read more.

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

(This article belongs to the Special Issue Fungal Pathogens Affecting Horticultural Crops)

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16 pages, 4515 KB

Open AccessArticle

Differential and Specific Analysis of Free Amino Acid Composition in Cucurbitaceae Fruits: A Multi-Tissue Study of 10 Species

by Dongdong Yang, Weikang Kong, Zihao Chen, Wenge Liu, Nan He, Xiaowen Luo, Jiayin Zhang, Danmei Zhu, Xuqiang Lu and Hongju Zhu

Horticulturae 2026, 12(9), 1129; https://doi.org/10.3390/horticulturae12091129 - 6 Sep 2026

Abstract

Free amino acids serve as a crucial hub connecting plant life activities with human nutrition. The fruits of Cucurbitaceae crops are natural nitrogen reservoirs, rich in free amino acids such as citrulline, arginine, and γ-aminobutyric acid (GABA). To investigate the spatial accumulation characteristics [...] Read more.

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

(This article belongs to the Special Issue Germplasm Resources and Genetics Improvement of Watermelon and Melon)

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24 pages, 8167 KB

Open AccessArticle

Phenotypic Characterization, Phenotypic Variation, and Phenotype–Environment Associations of Hovenia acerba Germplasm in Fujian, China: Its Multipurpose Utilization

by Jinling Feng, Xinyu Wen, Piao Yang, Qingshan Chen, Yu Huang, Yanjin Lin and Zhijian Yang

Horticulturae 2026, 12(9), 1128; https://doi.org/10.3390/horticulturae12091128 - 6 Sep 2026

Abstract

Hovenia acerba is a high-value multipurpose tree with edible, medicinal, and timber applications. However, systematic investigations of phenotypic variation, phenotypic diversity, and phenotype–environment associations for H. acerba germplasm in Fujian Province remain limited, which impedes targeted breeding and efficient resource exploitation. In this [...] Read more.

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

(This article belongs to the Section Genetics, Genomics, Breeding, and Biotechnology (G2B2))

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23 pages, 4840 KB

Open AccessArticle

Regulation of Rhythmic Photosynthesis by Photoperiod and Light Intensity in Non-Heading Chinese Cabbage: A Computational Approach

by Hengmin Lv, Yue Wu, Mengting Xiao, Jian Luo, Xilin Hou and Xiong You

Horticulturae 2026, 12(9), 1127; https://doi.org/10.3390/horticulturae12091127 - 5 Sep 2026

Abstract

Light is a key environmental factor regulating plant photosynthesis, yet the coordinated effects of photoperiod and light intensity on photosynthetic dynamics in non-heading Chinese cabbage remain unclear. Using experimental data, we developed a circadian clock-controlled photosynthesis model integrating photoperiod and light-intensity inputs. The [...] Read more.

Light is a key environmental factor regulating plant photosynthesis, yet the coordinated effects of photoperiod and light intensity on photosynthetic dynamics in non-heading Chinese cabbage remain unclear. Using experimental data, we developed a circadian clock-controlled photosynthesis model integrating photoperiod and light-intensity inputs. The model was calibrated and evaluated against experimental observations and was then used to analyze circadian gene expression, diurnal net photosynthetic rate (

P n

), light-period net CO₂ assimilation, and the marginal carbon benefit of increasing daily light integral (DLI). Under a constant DLI of 9.216 mol·m⁻²·d⁻¹, extending the photoperiod from 8 to 20 h while reducing light intensity from 320 to 128 µmol·m⁻²·s⁻¹ lowered and delayed the instantaneous

P n

peak but progressively increased light-period net CO₂ assimilation. Among the treatments examined, 20L:4D produced the highest net CO₂ assimilation. Moreover, across the simulated DLI range of 5–19 mol·m⁻²·d⁻¹, the 20-h photoperiod consistently produced the highest net assimilation, whereas the marginal carbon benefit of additional light declined by approximately 62%. The results suggest that distributing a fixed daily light input over a longer photoperiod at lower instantaneous light intensity can enhance daily carbon gain within the tested range, whereas increasing DLI produces progressively diminishing photosynthetic returns. This study provides a modeling framework for evaluating photoperiod–light intensity coordination and provides a quantitative basis for optimizing light–environment management in controlled-environment agriculture. Full article

(This article belongs to the Section Protected Culture)

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18 pages, 4564 KB

Open AccessArticle

Genome-Wide Characterization of the Cinnamyl Alcohol Dehydrogenase (CAD) Gene Family and Expression Profiling of Candidate ClCAD3 Gene Associated with Lignin Biosynthesis in Watermelon

by Tiantian Yang, Liyuan Yang, Jiejun Xu, Xiya Sun, Yi Tang and Chaonan Wang

Horticulturae 2026, 12(9), 1126; https://doi.org/10.3390/horticulturae12091126 - 5 Sep 2026

Abstract

Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step in lignin monomer biosynthesis and is crucial for plant cell-wall lignification. However, the CAD gene family and its role in watermelon rind lignification are poorly understood. In this study, we performed genome-wide bioinformatics analysis to [...] Read more.

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

(This article belongs to the Special Issue Cucurbitaceae Genetics, Physiology and Breeding)

18 pages, 15910 KB

Open AccessArticle

Identification and Expression Analysis of SHN Gene Family in Melon

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

Horticulturae 2026, 12(9), 1125; https://doi.org/10.3390/horticulturae12091125 - 5 Sep 2026

Abstract

SHN (SHINE) transcription factors belong to the AP2/ERF superfamily. They regulate cuticular wax biosynthesis and abiotic stress responses in plants, and play crucial roles in fruit netting development of cucurbit crops. However, a systematic genome-wide analysis of the SHN gene family in melon [...] Read more.

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

(This article belongs to the Special Issue Cucurbitaceae Genetics, Physiology and Breeding)

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26 pages, 13382 KB

Open AccessReview

Spectral Imaging and Autonomous Inspection Technologies for Nutrient Diagnosis of Protected Horticultural Crops: A Review

by Xiaodong Zhang, Shifang Song, Chuandong Guo, Xiangyu Han, Zonghua Leng and Yixue Zhang

Horticulturae 2026, 12(9), 1124; https://doi.org/10.3390/horticulturae12091124 - 5 Sep 2026

Abstract

Protected horticultural crops are commonly produced at high planting densities and have short production cycles; imbalances in water and fertilizer supply can rapidly affect plant vigor, yield, and quality. Non-destructive diagnostic methods are therefore needed to characterize plant nutritional status under greenhouse conditions. [...] Read more.

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

(This article belongs to the Special Issue Intelligent Agricultural Equipment Monitoring Technology for Vegetable Production)

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14 pages, 1791 KB

Open AccessArticle

Among Five Tomato Cultivars, the Responses to Low Iron (Fe) of the Main Fe-Uptake Proteins and Total Protein in Roots Correlate with Effects on Biomass and Chlorophyll

by Scott A. Heckathorn, Emina Kostic and Jennifer K. Boldt

Horticulturae 2026, 12(9), 1123; https://doi.org/10.3390/horticulturae12091123 - 5 Sep 2026

Abstract

Nutrient-uptake proteins (NUPs) have the potential to serve as biomarkers for crop improvement, with most studies to date focusing on NUP gene sequence or mRNA levels. In this paper, we examined if protein levels of the main iron (Fe)-uptake proteins in roots scaled [...] Read more.

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

(This article belongs to the Section Plant Nutrition)

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22 pages, 23603 KB

Open AccessReview

Canopy Regulation and Intelligent Branch Operations in Fruit-Tree Pruning: A Review

by Qunhao Zheng, Liuyang Yue, Liyang Su, Saike Jiang, Yinyin Tan and Xiongkui He

Horticulturae 2026, 12(9), 1122; https://doi.org/10.3390/horticulturae12091122 - 4 Sep 2026

Abstract

Fruit-tree pruning has to keep tree structure under control while continually renewing fruiting wood, and many decisions still depend on practical experience. This narrative review synthesizes 92 English-language publications from 1983 to 2026, identified through Google Scholar and backward citation tracking. As orchard [...] Read more.

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

(This article belongs to the Special Issue AI and Sensor Technologies for Smart Horticulture)

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14 pages, 14029 KB

Open AccessArticle

Integration of Multi-Omics Reveals Genomic Features of Chromatin Accessibility in Gardenia jasminoides J.Ellis Leaves

by Zhiyi Zhang, Yufang Hu, Qi Liang, Siqing Fan, Ling Zhang, Tingting Jing, Ying Xiong, Lang Yang, Mingkun Huang and Hua Yang

Horticulturae 2026, 12(9), 1121; https://doi.org/10.3390/horticulturae12091121 - 4 Sep 2026

Abstract

Chromatin accessibility is an important feature of cis-regulatory elements that shapes gene regulation in plants; however, it has been studied less frequently in traditional medicinal plants such as Gardenia jasminoides J.Ellis (G. jasminoides). This study applied Assay for Transposase-Accessible Chromatin using [...] Read more.

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

(This article belongs to the Special Issue Genome Alignment and Regulatory Genomics in Horticultural Crops)

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33 pages, 1222 KB

Open AccessReview

Medicinal and Aromatic Plant Micropropagation: A Sustainable Tool for Enhancing the Accumulation of Bioactive Molecules for Their Use in Food Systems

by Daniela Nicuță, Luminița Grosu, Roxana-Elena Voicu and Irina-Claudia Alexa

Horticulturae 2026, 12(9), 1120; https://doi.org/10.3390/horticulturae12091120 - 4 Sep 2026

Abstract

Plant tissue and cell culture techniques have proven to be a suitable tool for increasing fresh biomass and stimulating the plant secondary metabolite biosynthesis, offering important advantages compared to conventional plant propagation. Medicinal and aromatic plants represent species of interest due to their [...] Read more.

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

(This article belongs to the Special Issue Bioactive Compounds from Horticultural Plants and Plant Byproducts: Cultivating Innovation for a Sustainable Future in Food Systems)

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