Search Results (119)

In Saudi Arabia, cucurbit crops such as zucchini (Cucurbita pepo) and snake gourd (Trichosanthes cucumerina) are major vegetables and key dietary components, yet their associated viral threats remain poorly understood. We surveyed symptomatic cucurbit samples from greenhouses and open fields in the Al-Ahsa and Qatif regions. The detection methods employed included PCR, RCA, and Illumina NGS. Based on nucleotide sequence comparisons and maximum-likelihood phylogenetic analysis, we identified three viruses, i.e., TYLCV, WmCSV, and ToLCPalV, present as both single and mixed infections. Sequence analyses revealed a novel strain, TYLCV-Hasa, representing a distinct lineage of TYLCV. Analysis revealed that recombination occurred solely in the DNA-A components of the identified viruses, while DNA-B segments showed no evidence of recombination. Notably, no DNA satellites were detected, suggesting cucurbits may act as independent reservoirs of begomovirus diversity. These results provide a comprehensive genomic insight into cucurbit-infecting begomoviruses in Eastern Saudi Arabia. The discovery of TYLCV-Hasa and evidence of recombination raise concerns about the emergence of novel viral variants that could pose risks to cucurbit cultivation. The results establish a foundation for advanced molecular surveillance and breeding strategies, contributing to improved food security and supporting Saudi Arabia’s Vision 2030 goals for sustainable agriculture. Full article

The calmodulin-binding protein 60 (CBP60) family comprises essential Ca²⁺-responsive transcription factors that orchestrate salicylic acid (SA)-mediated immunity and broader stress responses. Despite being extensively characterized in model species, the CBP60 family remains poorly understood in watermelon (Citrullus lanatus), a globally significant cucurbit crop highly susceptible to aphid infestation and fusarium wilt. In this study, we performed a comprehensive genome-wide identification and characterization of the CBP60 gene family in watermelon, identifying 16 putative ClaCBP60 members, all of which harbor the conserved calmodulin-binding domain. These genes are non-randomly distributed across chromosomes, featuring a prominent cluster of 10 members on chromosome 3. Phylogenetic analysis across seven cucurbit species categorized the CBP60 proteins into four distinct subfamilies, revealing both evolutionary conservation and lineage-specific diversification. Gene structure and conserved motif analyses revealed shared core domains with subfamily-specific variations, indicative of functional divergence. Furthermore, synteny analysis showed strong collinearity with cucumber and melon, reflecting the evolutionary stability of key CBP60 loci. Transcriptional profiling under F. oxysporum infection and aphid infestation revealed dynamic expression patterns, with ClaCBP60_01 and ClaCBP60_16 exhibiting rapid and robust induction during the early stages of both stresses. These findings indicated that ClaCBP60 genes operate in a coordinated yet diversified manner to modulate defense signaling against F. oxysporum and aphid attack. This study provides a systematic insight into CBP60 family members in watermelon, establishing a foundation for validation and molecular breeding aimed at enhancing biotic tolerance. Full article

This literature review systematizes current data on the development of triploid seedless hybrids in the Cucurbitaceae Juss family. The absence of seeds simplifies the consumption and industrial preparation of products from cucurbits. In addition, triploids showed larger plant habitus, field resistance to infections, extended shelf life, and higher fruit quality. Phenotypic differences in polyploids can stem from altered chromatin organization and gene regulation, as the nucleus must accommodate a doubled chromosome set. The triploid watermelon cultivation method developed in 1951 failed to gain traction among other crops in the gourd (Cucurbitaceae) family. The challenges of triploid seed production and use include the need for the development of tetraploid and diploid parental lines, as well as bypassing the problem of the low viability of tetraploid parent pollen and the issue of thick seed coats and underdeveloped embryos in triploids. The research findings presented in this review can be applied to the development of triploid seedless hybrids for other members of the Cucurbitaceae family. Full article

Powdery mildew poses a persistent threat to global vegetable and fruit production, particularly affecting leafy crops such as lettuce, spinach, and cucurbits. Conventional control strategies including chemical fungicides, biological agents, and resistant cultivars face limitations due to resistance development, environmental toxicity, and inconsistent field efficacy. This review explores the emerging role of nanotechnology, specifically nanoparticles (NPs) and nanosuspensions (NSs), in managing powdery mildew. Metallic nanoparticles and non-metallic variants demonstrate potent antifungal activity through mechanisms such as membrane disruption, reactive oxygen species (ROS) generation, and gene regulation. Encapsulated nano-fungicides and sprayable essential oils represent potential application methods that could enhance delivery precision and activate plant defense mechanisms against powdery mildew. Integrating the application of nanoparticles and nanosuspensions with smart and digital delivery systems could be a promising strategy for managing powdery mildew infestation in fruits and vegetables. Despite their potential, challenges including ecotoxicity, formulation stability, scalability, and regulatory gaps must be addressed. This review underscores the need for interdisciplinary research to advance safe, effective, and sustainable nano-enabled solutions for powdery mildew control. Full article

Fusarium wilt of melon, caused by Fusarium fungi, results in sizeable economic losses worldwide. In Russia, data on the species composition of the causative pathogens of this disease on melon are lacking. From 2022 to 2025, 19 Fusarium isolates from the Volgograd and Rostov regions were included in a study that included species identification using molecular phylogenetic analysis of the tef1 and rpb2 loci, morphological description, and pathogenicity assessment against the host plant and other members of the Cucurbitaceae family. Four Fusarium species were found to be involved in the pathogenesis of Fusarium wilt of melon in Russia: F. clavus (37% of the total number of isolates), F. annulatum (21%), F. cf. inflexum (21%), and F. brachygibbosum (21%). All identified species were isolated in the Volgograd Region, while only F. cf. inflexum and F. brachygibbosum were isolated in the Rostov Region. This study reports for the first time the high pathogenicity of F. cf. inflexum and F. brachygibbosum species associated with melon wilt. Morphological variability and different aggressiveness of isolates of the species F. brachygibbosum and F. clavus, isolated in the Volgograd (-V) and Rostov (-R) regions in different years, were observed. The isolate F. brachygibbosum-V showed high aggressiveness both at the sprout and seedling stages, while the isolate F. brachygibbosum-R was characterized by moderate aggressiveness only at the sprout stage. High pathogenicity of the species isolated from melons was established for other cucurbit crops. F. cf. inflexum was also pathogenic for watermelon and pumpkin, and F. brachygibbosum was pathogenic for pumpkin. The obtained data will have practical value for the development of biological control measures against Fusarium fungi and will be used in a melon breeding program for resistance to Fusarium wilt. Full article

In this study, the insert length, location within the coat protein-encoding gene, and sequence orientation of the target fragment were optimized to construct an efficient virus-induced gene silencing (VIGS) system in melon using a Begomovirus solanumdelhiense vector. Existing systems are mostly RNA viruses, requiring in vitro synthesis of viral strands that are prone to degradation, although they exhibit high infectivity and stability in cucurbit hosts and ease of manipulation. This vector was selected for its more stable genome structure and these advantages. The melon phytoene desaturase (CmPDS), a key gene of carotenoid biosynthesis, was selected as a reporter gene to evaluate the effects of the VIGS system. Our results revealed that the melon leaves in all the VIGS treatments exhibited a typical photobleaching phenotype at 21 days post-inoculation. Moreover, reverse transcription quantitative real-time PCR revealed a significant reduction in the mRNA levels of PDS in melon. The highest silencing efficiency (lowest PDS mRNA levels) was achieved by the VIGS vector harboring a 165 bp CmPDS fragment at the 3′ end of the AV1. These findings not only establish a more efficient VIGS protocol for melon but also provide a foundation for developing novel virus-based silencing tools applicable to functional genomics and cucurbit crop improvement, particularly for traits requiring precise gene expression modulation such as disease resistance and fruit quality. Full article

Powdery mildew represents one of the most significant challenges for cucurbit crops. In recent decades, progress has been made in identifying resistance sources that improve yield and quality while reducing fungicide use. This study explored the molecular mechanisms underlying cucurbit responses to powdery mildew through comparative RNA-seq of two contrasting Cucurbita pepo cultivars: the partially resistant 968Rb and the susceptible True French. Differential expression analysis between inoculated and non-inoculated conditions identified 398 DEGs in 968Rb and 1129 in True French. In 968Rb, a stronger defense response emerged with cell wall reinforcement and upregulation of fructose-1,6-biphosphate aldolase genes, while True French showed activation of chitinase genes. Machine learning models, including Random Forest and K-means, identified expression features and gene modules linked to resistance. By combining conventional and Artificial Intelligence-based analyses, we identified a putative adaptive genetic variation, supported by a higher single nucleotide polymorphism density within expression clusters enriched for upregulated genes in the partial resistant cultivar 968Rb. The integration of Artificial Intelligence tools in our pipeline facilitated the understanding of the genetic basis of Cucurbita pepo resistance to Podosphaera xanthii, highlighting the transcriptional modules and variant patterns associated with resistance traits, and providing a scalable framework for future applications in crop improvement. Full article

RNA methylation, particularly N6-methyladenosine (m⁶A) and 5-methylcytosine (m⁵C), functions as a pivotal post-transcriptional regulatory mechanism and plays a central role in plant growth, development, and stress responses. This review provides a systematic summary of recent advances in RNA methylation research in cucurbit crops. To date, high-throughput technologies such as MeRIP-seq and nanopore direct RNA sequencing have enabled the preliminary construction of RNA methylation landscapes in cucurbit species, revealing their potential regulatory roles in key agronomic traits, including fruit development, responses to biotic and abiotic stresses, and disease resistance. Nevertheless, this field remains in its early stages for cucurbit crops and faces several major challenges: First, mechanistic understanding is still limited, with insufficient knowledge regarding the composition and biological functions of the core protein families involved in methylation dynamics—namely, “writers,” “erasers,” and “readers.” Second, functional validation remains inadequate, as direct evidence linking specific RNA methylation events to downstream gene regulation and phenotypic outcomes is largely lacking. Third, resources are scarce; compared to model species such as Arabidopsis thaliana and rice, cucurbit crops possess limited species-specific genetic data and genetic engineering tools (e.g., CRISPR/Cas9-based gene editing systems), which significantly hampers comprehensive functional studies. To overcome these limitations, future research should prioritize the development and application of more sensitive detection methods, integrate multi-omics datasets—including transcriptomic and methylomic profiles—to reconstruct regulatory networks, and conduct rigorous functional assays to establish causal relationships between RNA methylation modifications and phenotypic variation. The ultimate objective is to fully elucidate the biological significance of RNA methylation in cucurbit plants and harness its potential for crop improvement through genetic and biotechnological approaches. Full article

Effective implementation and optimization of organic amendments and other management practices is essential for sustainable organic vegetable production, yet needed information is lacking on the effects and benefits of different organic matter amendments and pest management approaches under Northeastern USA production conditions. The impacts of soil amendments of biochar or humus (soluble humate complex) in conjunction with compost, as well as the presence or absence of an early-season insect netting row cover (mesotunnels), were evaluated on soil chemical and biological properties, crop development and yield, and disease and pest issues in organic vegetable production, as represented by legume (green snap bean), cucurbit (green zucchini squash), and amaranth (garden beet) vegetable crops, in a three-year field trial in Maine. Composted cow manure and a commercial organic fertilizer alone were included as controls. All plots were either covered or not covered with a permeable insect netting row cover from the time of planting until flowering. All compost-based amendments increased soil pH; organic matter; microbial activity; crop yields; and K, Mg, and Ca content relative to a fertilizer-only treatment. Biochar amendments further increased soil pH, CEC, and Ca content above those of compost alone and also resulted in the overall highest yields of bean and zucchini but were not significantly greater than with compost amendment alone. Humus amendments did not improve soil characteristics, with some indications of potential reductions in emergence and yield. Insect netting substantially improved yield of zucchini (by 59%) and somewhat improved bean yield (by 11%), in addition to improving plant emergence and reducing insect leaf damage, but it did not reduce powdery mildew on zucchini or provide any significant benefits for beets. These results help define specific management practices to improve organic vegetable production and provide useful information and options for growers. Full article

Pumpkin is widely used as a rootstock to enhance salt tolerance and improve productivity of Cucurbit crops. To date, the morphology and ion parameters of pumpkins at a certain time point under salt stress are well-known. However, the dynamic changes in organ morphology and K⁺/Na⁺ content of pumpkin under salt stress and the relationship of them remain unclear. Therefore, this study investigated biomass, root morphology, stem structure, and K⁺/Na⁺ content in salt-sensitive (JZ-1) and salt-tolerant (JYZ-1) pumpkins under 0 mM and 120 mM NaCl conditions at 2, 5, and 10 days after treatment (DAT). Our results show that at the beginning, NaCl treatment led to a sharp decrease in shoot fresh weight by 30–53% and a slight decrease in root fresh weight, plant dry weight, and total root length and affects the K⁺ and Na⁺ content both in JZ-1 and JYZ-1 at 2 DAT. Subsequently, total root volume and number of tips have changed, in which NaCl treatment resulted in a significant increase of 127% in total root volume and a significant decrease of 38.4% in number of tips in JYZ-1 at 5 DAT, but no significant difference in JZ-1 at 5 DAT was found. At the end, root fresh weight and stem structure parameters were significantly decreased by NaCl treatment at 10 DAT both in JZ-1 and JYZ-1, and stem cross-sectional area under NaCl conditions in JZ-1 and JYZ-1 at 10 DAT (2.133 and 2.316 mm³, respectively) was significantly lower than that under control conditions (2.933 and 4.441 mm³, respectively). Additionally, shoot K⁺ content showed a trend of first upward and then downward in JZ-1 and a slightly decreasing trend in JYZ-1, and shoot Na⁺ content displayed a trend of first downward and then upward in JZ-1 and a slightly increasing trend in JYZ-1. It is suggested that shoot K⁺ content, shoot Na⁺ content, and total root volume be considered as the important parameters for pumpkin salt tolerance assessment. These findings will help us better understand the mechanisms of salt tolerance and improve the efficiency of identification of salt-tolerant pumpkin. Full article

Grafting is an effective horticultural technique that significantly enhances disease resistance and stress tolerance in watermelon. This review systematically summarizes the types of rootstocks used in watermelon grafting and analyzes the effects of grafting on plant responses to biotic stresses, such as viral and fungal pathogens, root-knot nematodes infections, and abiotic stresses, including drought, temperature extremes, and salinity. Furthermore, it discusses the changes in fruit quality and explores the underlying mechanisms associated with graft-induced resistance. By synthesizing recent research advances, this review aims to offer valuable insights and practical references for improving resistance and promoting sustainable production in cucurbit and other vegetable crops through grafting. As a sustainable cultivation strategy, grafting demonstrates considerable potential for enhancing watermelon resilience and yield; however, optimizing fruit quality remains a critical focus for future research. Full article

Cucumber green mottle mosaic virus (CGMMV, Tobamovirus viridimaculae) is a tobamovirus that induces leaf green mottling, mosaic patterns, bleaching, fruit sponginess, rotting, and malformation symptoms in various cucurbit crops. The underlying mechanisms by which CGMMV elicits these symptoms have yet to be elucidated. In the present study, we observed that the infection of CGMMV in bottle gourd, but not in N. benthamiana, led to the significant upregulation of a key gene involved in chlorophyll degradation, Chlorophyllase 1 (CLH1). This induction may be closely linked to chlorophyll degradation, particularly that of chlorophyll a (Clh a) in bottle gourd plants. Phylogenetic analysis showed that the amino acid sequence of BgCLH1 has a closer relationship with those of CLH1 from other cucurbit crops and has a relatively farther relationship with those of the well-studied CLH1 from Arabidopsis thaliana and Citrus sinensis. Further, confocal microscopy analysis indicated that BgCLH1 may be localized to the cytoplasm instead of the chloroplast. Moreover, silencing of the BgCLH1 gene not only reduced viral accumulation but also resulted in an increase in chlorophyll content. Similar results were also observed in watermelon, suggesting that this regulatory mechanism may be conserved across cucurbit crops. Our findings thus reveal a complex and intricate interplay between viral infection and the chlorophyll metabolic pathway. Full article

Lagenaria siceraria is an essential horticultural and medicinal crop that is used for its edible fruits and ornamental purposes. WRKY transcription factors have been extensively studied in plant responses to environmental stress; however, there is limited information on their specific functions in L. siceraria. In this study, 51 LsWRKY genes were identified in the L. siceraria genome. The 51 LsWRKYs were divided into classes I, II, and III based on evolutionary analysis. Members of each class have similar conserved motifs and exon-intron structures, and promoter analysis helped identify many cis-regulatory elements associated with growth, hormones, and stress responses. GO terms and KEGG analyses indicated the potential roles of LsWRKY in the regulation of bottle gourd development and acclimation to various environmental stressors. Significant differences in LsWRKY expression were observed between different tissues. The results of RNA-seq and qRT-PCR showed that LsWRKYs were expressed in a tissue- and development-specific manner under normal growth conditions. LsWRKY abundance showed a clear pattern of change related to stress when L. siceraria was exposed to unfavorable environmental conditions. This study provides new insights into the role of LsWRKYs in the growth and stress responses of cucurbits. Full article

Watermelon (Citrullus lanatus) and melon (Cucumis melo) are globally important cucurbit crops, with China being the largest producer and consumer. Traditional breeding methods face difficulties in significantly improving yield and quality. Smart breeding, which combines genomics, gene editing, and artificial intelligence (AI), holds great promise but fundamentally depends on understanding the molecular mechanisms controlling important agronomic traits. This review summarizes the progress made over recent decades in discovering and understanding the functions of genes that control essential traits in watermelon and melon, focusing on plant architecture, fruit quality, and disease resistance. However, major challenges remain: relatively few genes have been fully validated, the complex gene networks are not fully unraveled, and technical hurdles like low genetic transformation efficiency and difficulties in large-scale trait phenotyping limit progress. To overcome these and enable the development of superior new varieties, future research priorities should focus on the following: (1) systematic discovery of genes using comprehensive genome collections (pan-genomes) and multi-level data analysis (multi-omics); (2) deepening the study of gene functions and interactions using advanced gene editing and epigenetics; (3) faster integration of molecular knowledge into smart breeding systems; (4) solving the problems of genetic transformation and enabling efficient large-scale trait and genetic data collection (high-throughput phenotyping and genotyping). Full article

Cold stress can inhibit the growth of cucurbits, disrupt pollination and fertilization, induce fruit deformities, reduce plant resistance, and increase susceptibility to diseases, ultimately resulting in yield reduction, quality deterioration, or even complete crop failure. This review focuses on the main cucurbits, such as melon, cucumber, and watermelon, systematically expounding the roles of plant hormones, signaling molecules, soluble sugars, key regulatory factors, molecular mechanisms, and network interactions in their response to cold stress. Furthermore, it highlights future research directions and application potential. By analyzing existing challenges and prospective advancements in this field, the review aims to provide a comprehensive reference for facilitating genetic improvement in cold tolerance. Full article