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BackgroundThe sweet potato whitefly (Bemisia tabaci) is a globally important insect pest that damages crops through direct feeding and by transmitting viruses. Current B. tabaci management revolves around the use of insecticides, which are economically and environmentally costly. Host plant resistance is a sustainable option to reduce the impact of whiteflies, but progress in deploying resistance in crops has been slow. A major obstacle is the high cost and low throughput of screening plants for B. tabaci resistance. Oviposition rate is a popular metric for host plant resistance to B. tabaci because it does not require tracking insect development through the entire life cycle, but accurate quantification is still limited by difficulties in observing B. tabaci eggs, which are microscopic and translucent. The goal of our study was to improve quantification of B. tabaci eggs on several important crop species: cassava, cowpea, melon, sweet potato and tomato.ResultsWe tested a selective staining process originally developed for leafhopper eggs: submerging the leaves in McBryde's stain (acetic acid, ethanol, 0.2% aqueous acid Fuchsin, water; 20:19:2:1) for three days, followed by clearing under heat and pressure for 15 min in clearing solution (LGW; lactic acid, glycerol, water; 17:20:23). With a less experienced individual counting the eggs, B. tabaci egg counts increased after staining across all five crops. With a more experienced counter, egg counts increased after staining on melons, tomatoes, and cowpeas. For all five crops, there was significantly greater agreement on egg counts across the two counting individuals after the staining process. The staining method worked particularly well on melon, where egg counts universally increased after staining for both counting individuals.ConclusionsSelective staining aids visualization of B. tabaci eggs across multiple crop plants, particularly species where leaf morphological features obscure eggs, such as melons and tomatoes. This method is broadly applicable to research questions requiring accurate quantification of B. tabaci eggs, including phenotyping for B. tabaci resistance.

The article demonstrates the Brix content of melon fruits grafted with different varieties of rootstock using Support Vector Regression (SVR) and Multiple Linear Regression (MLR) model approaches. The analysis yielded primary fruit biochemical measurements on the following rootstocks, Sphinx, Albatros, and Dinero: nitrogen, phosphorus, potassium, calcium, and magnesium. Established models were evaluated with Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), Mean Square Error (MSE), Root Mean Square Error (RMSE), and Coefficient of Determination (R2) metrics. In the test section, the results of the MLR model were calculated as MAE: 0.0728, MAPE: 0.0117, MSE: 0.0088, RMSE: 0.0936, and R2: 0.9472, while the results of the SVR model were calculated as MAE: 0.0334, MAPE: 0.0054, MSE: 0.0016, RMSE: 0.0398, and R2: 0.9904. Despite both models performing well, the SVR model showed superior accuracy, outperforming MLR by 54% to 82% in terms of predictions. The relationships between Brix levels and various nutrients, such as sucrose, glucose, and fructose, were found to be strong, while titratable acidity had a minimal effect. SVR was found to be a more reliable, non-destructive method for melon quality assessment. These findings revealed the relationship between Brix and sugar levels on melon quality. The study highlights the potential of these machine learning models in optimizing the rootstock effect and managing melon cultivation to improve fruit quality. [ABSTRACT FROM AUTHOR]

Background: Chilling stress is a key abiotic stress that severely restricts the growth and quality of melon (Cucumis melo L.). Few studies have investigated the mechanism of response to chilling stress in melon. Results: We characterized the physiological, transcriptomic, and metabolomic response of melon to chilling stress using two genotypes with different chilling sensitivity ("162" and "13-5A"). "162" showed higher osmotic regulation ability and antioxidant capacity to withstand chilling stress. Transcriptome analysis identified 4395 and 4957 differentially expressed genes (DEGs) in "162" and "13-5A" under chilling stress, respectively. Metabolome analysis identified 615 and 489 differential enriched metabolites (DEMs) were identified in "162" and "13-5A" under chilling stress condition, respectively. Integrated transcriptomic and metabolomic analysis showed enrichment of glutathione metabolism, and arginine (Arg) and proline (Pro) metabolism, with differential expression patterns in the two genotypes. Under chilling stress, glutathione metabolism-related DEGs, 6-phosphogluconate dehydrogenase (G6PDH), glutathione peroxidase (GPX), and glutathione s-transferase (GST) were upregulated in "162," and GSH conjugates (L-gamma-glutamyl-L-amino acid and L-glutamate) were accumulated. Additionally, "162" showed upregulation of DEGs encoding ornithine decarboxylase, Pro dehydrogenase, aspartate aminotransferase, pyrroline-5-carboxylate reductase, and spermidine synthase and increased Arg, ornithine, and Pro. Furthermore, the transcription factors (TFs), MYB, ERF, MADS-box, and bZIP were significantly upregulated, suggesting their crucial role in chilling tolerance of melon. Conclusions: These findings elucidate the molecular response mechanism to chilling stress in melon and provide insights for breeding chilling-tolerant melon. [ABSTRACT FROM AUTHOR]

Background: Melon (Cucumis melo L.), an important cucurbit crop, faces production limitations due to powdery mildew (PM). Developing resistant varieties offers a sustainable, genetics-based alternative to chemical treatments. Therefore, identifying PM resistance quantitative trait loci (QTL) and creating trait-associated markers are essential for efficient melon PM resistance improvement through marker-assisted backcrossing (MABC). Results: Three F2 populations, A6, B2, and C4, were generated for QTL mapping of PM resistance. Major QTL were identified on chromosome 2 in A6, chromosome 5 in B2, and chromosomes 5 and 12 in C4. A series of TaqMan® assays targeting regions on chromosomes 2, 5, and 12 were developed and validated for foreground and recombinant selection, complemented by the double digest restriction-site associated DNA genotyping system to evaluate the recurrent parent genome recovery. Three MABC programs using resistant donor parents from A6 and C4 crossed with elite susceptible recurrent parents with green and orange fruit flesh were implemented. After two to three cycles of MABC, individual QTL was successfully introgressed into elite genetic backgrounds, giving six PM resistance lines in each green- and orange-fleshed background. PM inoculation on the twelve near-isogenic lines confirmed their resistance to PM. Conclusions: We have identified major PM resistance QTL for melon on chromosomes 2, 5, and 12 and have introgressed individual QTL to elite genetic backgrounds using MABC in three and a half years. This study demonstrates the power of combining high-throughput genotyping with breeding efforts and showcases the efficiency of molecular breeding. [ABSTRACT FROM AUTHOR]

Hydroponic systems offer a promising solution for urban farming and the utilization of unproductive land. Successful implementation, however, requires careful optimization to select the most effective hydroponic system tailored to specific plants and environmental conditions. This study aims to compare the growth and physiological responses of Madesta melons (Cucumis melo L. cv. Madesta) cultivated using the nutrient film technique (NFT) and drip irrigation system (DIS) with variations in growth media. The Madesta melon seeds underwent a two-week germination phase in coco peat media, followed by transplanting into NFT and DIS setups utilizing diverse growth media, including rice husk, rice husk mixed with compost, and compost only. Over four weeks post-cultivation, assessments were conducted on key growth metrics such as leaf count, leaf diameter, plant height, and stem diameter. Plant physiological responses were also analyzed, encompassing chlorophyll and nitrogen levels, along with the mineral composition within leaves and fruits. Results revealed that the DIS cultivation outperformed the NFT in terms of growth outcomes. Among the varied media combinations, the rice husk and compost blend supported growth most effectively. Notably, no significant differences were observed in leaf and fruit nitrogen content between the DIS and NFT systems, and the overall mineral content of the media remained relatively stable before and after the cultivation period. Mineral content analysis revealed calcium as the predominant element in the leaves, while potassium emerged as the most abundant mineral in the fruits. This research sheds light on the potential of hydroponic systems, specifically the DIS method, for enhancing melon cultivation, emphasizing the importance of selecting appropriate growth media to maximize plant growth. [ABSTRACT FROM AUTHOR]

Melon (Cucumas melon) is widely cultivated and popular because of its quality value and unique flavor. However, the continuous cropping of melons in greenhouses has various negative effects on the soil environment, melon growth, and quality. Recently, farmers have utilized organic fertilization, especially vermicompost, for melons to resist the harmful effects of continuous cropping. A field experiment was conducted to explore the effects of vermicompost on soil microbes and melon fruit quality via high throughput sequencing and chemical sequencing methods. The results showed that the application of vermicompost decreased (p < 0.05) soil pH and increased organic matter, available phosphorus, biomass, urease, catalase, peroxidase, and alkaline phosphatase. A total of 3447 bacterial and 718 fungal operational taxonomic units were identified in all soil samples. Application of vermicompost decreased (p < 0.05) the relative abundances of Acidobacteriota, Gemmatimonadota, Actinobacteriota, and unclassified and increased the relative abundance of Planctomycetota. Compared with the control soil, vermicompost application resulted in significantly higher bacterial Chao indices and a significantly lower Chao index under vermicompost of 60 t ha−1 based on farmers' normal fertilizer and significantly lower diversity under vermicompost of 90 t ha−1. Otherwise, vermicompost application increased the photosynthetic rate and chlorophyll content of melon leaves and increased the total sugar, soluble solids, vitamin C, soluble protein, and organic acid contents of melon. The results of redundancy analysis indicated that Proteobacteria exhibited a positive correlation with soil ammonium nitrogen (AN) and pH, while showing a negative association with soil available phosphorus and organic matter. Spearman's correlation analysis revealed that both total sugar content and central soluble solid content in melon had a significant positive correlation (p < 0.05) with Patescibacteria. This study demonstrates that the application of vermicompost alters the microbial community structure in melon cultivation, enhancing fruit quality; this not only promotes a healthier soil ecosystem but also contributes to sustainable and productive practices in melon farming. [ABSTRACT FROM AUTHOR]

Parthenogenesis is an important way for melon (Cucumis melo L.) haploid production, but difficulties remain in low induction rate, embryo rescue, and chromosome doubling. Wide hybridization of Gramineae crops can directly obtain maternal haploids without embryo rescue and then form double haploids by chromosome doubling. However, this method has not been applied to the melon. To broaden the double haploid creation pathway in melon, seven cross combinations of the genus Cucumis were used for wide hybridization. After pollination, the ovary was treated with forchlorfenuron and thidiazuron to promote embryonic development and chromosome doubling. Results demonstrated that the fruit setting rate was 67.67–84.00%. However, most of the fruits were parthenocarpic (empty seeds), and only one fruit from the combination of BPC-4 (C. melo 'baipicui') × YPJ-6 (C. sativus L.) obtained 3 mature seeds. After the 3 seeds germinated, only one seed developed into a plant. Then, the plant (F1) was selfed and obtained F2 and F3. Chromosome counts showed that F2 was diploid (2n = 2x = 24). Compared to BPC-4, the visible variation of compact on botanical traits appeared in F2 and F3 and was uniform in population among F2 and F3. 27 SSR polymorphic markers demonstrated that the maternal origin of gene locus and homozygosity of the F2 hybrid plants. Genome resequencing analysis showed that the F2 genomes were further purified by 0.24% compared to BPC-4. Therefore, the hybrid offsprings were double haploid. In conclusion, we are the first to induce a melon double haploid by wide hybridization. [ABSTRACT FROM AUTHOR]

SUMMARY: The external appearance of fruit commodities is an essential trait that has profound effects on consumer preferences. A natural melon variety, characterized by an uneven and patchy arrangement of dark green streaks and spots on the white‐skinned rind, resembles shooting stars streaking across the sky; thus, this variety is called "Shooting Star" (SS). To investigate the mechanism underlying the SS melon rind pattern, we initially discovered that the variegated dark green color results from chlorophyll accumulation on the white skin. We then constructed a segregation population by crossing a SS inbred line with a white rind (WR) inbred line and used bulk segregant analysis (BSA) revealed that the SS phenotype is controlled by a single dominant gene, CmAPRR2, which has been previously confirmed to determine dark green coloration. Further genomic analysis revealed a hAT‐like transposable element (TE) inserted in CmAPRR2. This TE in CmAPRR2 is recurrently excised from rind tissues, activating the expression of CmAPRR2. This activation promotes the accumulation of chlorophyll, leading to the variegated dark green color on the rind, and ultimately resulting in the SS rind phenotype. Therefore, we propose that the SS phenotype results from the recurrent excision of the hAT‐like TE in CmAPRR2. Significance Statement: Currently, there are numerous studies on transposons in asexual reproduction, but few focus on their role in sexual reproduction. In this paper, we investigate melon skin color through map‐based cloning to locate the gene responsible for skin color and identify the transposons affecting it. [ABSTRACT FROM AUTHOR]

Leaf stalk-stem angle is an important agronomic trait influencing melon architecture, photosynthetic efficiency, and crop yield. However, the mechanisms governing leaf stalk-stem angle, particularly in melon, are not well understood. In this study, we explored the comparative transcriptome in the expanded architecture line Y164 and the compact plant architecture line Z151 at 30 days after pollination. Phytohormones were measured at the leaf stalk-angle site at the same time in these two lines using liquid chromatography (LC) tandem mass spectrometry (MS) (LC-MS/MS). The phytohormones and transcriptomes were jointly analyzed. Differential hormone profiling revealed that the levels of 1-aminocyclopropane-1-carboxylate (ACC) and 12-oxophytodienoic acid (OPDA) in the large-angled line Y164 were significantly higher than those in the small-angled line Z151. These differences were quantified as 2.1- and 2.8-fold increases, respectively. Conversely, the content of isopentenyl adenosine (IPA) was significantly elevated in Z151, with a 3.8-fold higher concentration relative to Y164. Transcriptome analysis identified a total of 1709 differently expressed genes (DEGs), with a predominant enrichment in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to photosynthesis and plant hormone signal transduction. Similarly, photosynthesis and the hormone metabolic process were predominantly enriched in the biological process of Gene Ontology (GO) terms. Further integration of transcriptome and hormone analyses substantiated the close relationship between melon leaf stalk-stem angle and phytohormones, especially ACC, OPDA and IPA. Selected DEGs from phytohormone signal transduction were validated. Detailed analysis of DEGs highlighted the potential role of genes such as GH3s (LOC103490488, LOC103490483), SUARs (LOC107991561, LOC103497281 and LOC103489067), ARFs (LOC103503893, LOC103493078) and five genes in abscisic acid pathway. In summary, our findings strongly suggest a direct correlation between phytohormones and the leaf stalk-stem angles in melon. [ABSTRACT FROM AUTHOR]

Irradiated pollen pollination combined with embryo rescue is an effective method to induce haploid melons, but it has the disadvantage of low embryo formation efficiency. This study aims to improve the efficiency of this technique in embryo rescue. Firstly, three methods of detecting embryo-containing seeds were compared, which were light box, solid culture, and liquid culture, and the solid culture method was selected for the follow-up experiments. The results showed that a significant variation occurred in both the rate of embryo yield (ROEY) and the rate of turned green embryo (ROTGE) among 12 melon genotypes, ranging from 1.39% to 0 and from 1.05% to 0, respectively. Subsequently, melon materials G6, G61, and G6B were used as materials to design a full-factor experiment, focusing on embryo rescue time (calculated as Days After Pollination, DAP) and the rescue medium. The results showed that the highest proportions of ROEY and ROTGE were 0.89% and 0.64% at 18 DAP, while the proportions of ROEY and ROTGE were 0.71% and 0.27% at 24 DAP, and 0.7% and 0.28% at 30 DAP, respectively. Furthermore, 0.57% of ROTGE was obtained using MS medium supplemented with 0.2 mg/L 6-BA, exceeding the 0.25% obtained using the MS basal medium alone. Consequently, the method of embryo rescue at 18 DAP on MS + 0.2 mg/L 6-BA medium was referred to Treat-A and was then validated across 15 melon genotypes. The result showed a significant improvement in embryo rescue efficiency, with 1.38- and 2.65 times increase in ROEY and ROTGE respectively. Interestingly, Treat-A also resulted in a 2.05-fold increase in the Rate of regeneration plant (P1). Finally, 13 genotype haploids were treated with 200 mg/L to successfully achieve doubled haploids, with a doubling rate varying from 35% down to 0. In summary, this study presents an improved approach to embryo rescue and has acquired 151 haploids for future melon breeding.Key message: This research improves the embryo rescue efficiency of the irradiated pollen-induced haploid technique. [ABSTRACT FROM AUTHOR]

Through the integration of genomic information, transcriptome sequencing data, and bioinformatics methods, we conducted a comprehensive identification of the ALDH gene family in melon. We explored the impact of this gene family on melon growth, development, and their expression patterns in various tissues and under different stress conditions. Our study discovered a total of 17 ALDH genes spread across chromosomes 1, 2, 3, 4, 5, 7, 8, 11, and 12 in the melon genome. Through a phylogenetic analysis, these genes were classified into 10 distinct subfamilies. Notably, genes within the same subfamily exhibited consistent gene structures and conserved motifs. Our study discovered a pair of fragmental duplications within the melon ALDH gene. Furthermore, there was a noticeable collinearity relationship between the melon's ALDH gene and that of Arabidopsis (12 times), and rice (3 times). Transcriptome data reanalysis revealed that some ALDH genes consistently expressed highly across all tissues and developmental stages, while others were tissue- or stage-specific. We analyzed the ALDH gene's expression patterns under six stress types, namely salt, cold, waterlogged, powdery mildew, Fusarium wilt, and gummy stem blight. The results showed differential expression of CmALDH2C4 and CmALDH11A3 under all stress conditions, signifying their crucial roles in melon growth and stress response. RT-qPCR (quantitative reverse transcription PCR) analysis further corroborated these findings. This study paves the way for future genetic improvements in melon molecular breeding. [ABSTRACT FROM AUTHOR]

Summary: Many biotic or abiotic factors such as CPPU (N‐(2‐chloro‐pyridin‐4‐yl)‐N′‐phenylurea), a growth regulator of numerous crops, can induce bitterness in cucurbits. In melon, cucurbitacin B is the major compound leading to bitterness. However, the molecular mechanism underlying CuB biosynthesis in response to different conditions remains unclear. Here, we identified a set of genes involved in CPPU‐induced CuB biosynthesis in melon fruit and proposed CmBr gene as the major regulator. Using CRISPR/Cas9 gene editing, we confirmed CmBr's role in regulating CuB biosynthesis under CPPU treatment. We further discovered a CPPU‐induced MYB‐related transcription factor, CmRSM1, which specifically binds to the Myb motif within the CmBr promoter and activates its expression. Moreover, we developed an introgression line by introducing the mutated Cmbr gene into an elite variety and eliminated CPPU‐induced bitterness, demonstrating its potential application in breeding. This study offers a valuable tool for breeding high‐quality non‐bitter melon varieties and provides new insights into the regulation of secondary metabolites under environmental stresses. [ABSTRACT FROM AUTHOR]

Melon damping off, which has a negative impact on melon quality and yield, can be safely and effectively managed with Trichoderma. Melon cultivar 'Longtian No. 1' was evaluated at both the adult and seedling stages in a pot experiment. The Rs and PD liquids were utilized as CK1 and CK2, respectively. Trichoderma viride Tv286 treatments T1B, T2B, T3B, and T4B were used based on Rs at concentrations of 104, 105, 106, and 107 CFU·g−1, respectively. The impact of several treatments on the antioxidant system and seedling quality of melon were assessed at 15, 25, and 35 days after sowing. We examined the effects of several treatments on melon quality, yield attributes, and physiological and biochemical markers during the adult stage at 10, 20, and 30 days after pollination. The effects of several treatments on melon damping off were also studied. Applying T. viride Tv286 at different rates effectively increased the activities of enzymes, including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), and polyphenol oxidase (PPO), in the leaves of melon seedlings, significantly reduced the malondialdehyde (MDA) content, and improved the root–shoot ratio and seedling strength index. In terms of its influence on promoting the effect of antioxidant system indicators, T3B performed well. Melon seedlings treated with T3B showed higher CAT, POD, SOD, APX, and PPO activities in their leaves 35 days after sowing compared to CK1 (189.74, 169.61, 175.36, 224.20, and 477.39%, respectively). The strong seedling index and root–shoot ratio showed improvements of 130.43 and 79.71%, respectively, and the MDA content dropped by 35.66% at 35 days after sowing compared to CK1. Varying the rates at which T. viride Tv286 was applied increased the nitrate reductase (NR) activity and nitrate nitrogen, proline (Pro), chlorophyll, soluble sugar, and soluble protein contents in mature melon leaves, increasing melon quality and yield. T3B is the most effective marketing campaign. Compared to CK1, mature T3B leaves had higher NR activity, nitrate nitrogen content, chlorophyll content, soluble sugar content, soluble protein content, and Pro content 30 days after melon pollination (100.40, 135.17, 68.59, 93.65, 158.13, and 238.67%, respectively). The soluble solids, soluble protein, soluble sugar, vitamin C contents, and yield of melon fruit increased by 50.07, 126.82, 60.62, 70.79, and 61.45%, respectively, at 30 days after melon pollination compared to CK1. Optimal management of melon damping off can be accomplished with the application of T. viride Tv286 at different concentrations, with T3B exhibiting the best effect. The control effects reached 90.48 and 72.99% at the seedling and adult stages, respectively. Overall, T. viride Tv286 improved seedling quality, damping off control efficacy, melon yield and quality, and the antioxidant system during the seedling stage and enhanced physiological and biochemical characteristics during the adult stage. This study indicates the potential of T. viride Tv286 conidia as a biological control agent because it can prevent plant disease, increase yield, and improve quality. [ABSTRACT FROM AUTHOR]

The morphogenesis of higher plants requires communication among distant organs throughout vascular tissues (xylem and phloem). Numerous investigations have demonstrated that phloem also act as a distribution route for signalling molecules being observed that different macromolecules translocated by the sap, including nucleic acids and proteins, change under stress situations. The participation of extracellular vesicles (EVs) in this communication has been suggested, although little is known about their role. In fact, in the last decade, the presence of EVs in plants has originated a great controversy, where major concerns arose from their origin, isolation methods, and even the appropriate nomenclature for plant nanovesicles. Phloem sap exudates from melon plants, either aphid‐free or infested with Aphis gossypii, were collected by stem incision. After sap concentration (Amicon), phloem EVs (PhlEVs) were isolated by size exclusion chromatography. PhlEVs were characterised using Nanoparticle Tracking Analysis, Transmission electron microscopy and proteomic analysis. Here we confirm the presence of EVs in phloem sap in vivo and the detection of changes in the particles/protein ratio and composition of PhlEVs in response to insect feeding, revealing the presence of typical defence proteins in their cargo as well as components of the proteasome complex. PhlEVs from infested plants showed lower particles/protein ratio and almost two times more proteolytic activity than PhlEVs from aphid‐free plants. In both cases, such activity was inhibited in a dose‐dependent manner by the proteasome inhibitor MG132. Our results suggest that plants may use this mechanism to prepare themselves to receive infectious agents and open up the possibility of an evolutionary conserved mechanism of defence against pathogens/stresses in eukaryotic organisms. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bacterial fruit blotch (BFB), known as the 'cancer' of cucurbits, is a seed‐borne disease of melons caused by Acidovorax citrulli. Traditional chemical treatments for BFB are ineffective and adversely affect the environment. Using dielectric barrier discharge (DBD) nanosecond‐pulsed plasma technology, melon seeds were treated to promote germination and growth and to control BFB. RESULTS: Based on the evaluation parameters of seed germination, seedling growth, leaf yellowing and bacterial infection after seed plasma treatments, 9 min at 20 kV was selected as the optimal plasma discharge parameter. In this study, seedling growth was significantly improved after treating melon seeds carrying A. citrulli using this discharge parameter. The number of first true leaves measured on the eighth day was 2.3 times higher and the disease index was reduced by 60.5% compared to the control group. Attenuated total reflectance–Fourier transform infrared measurements show that plasma treatments penetrate the seed coat and denature polysaccharides and proteins in the seed kernel, affecting their growth and sterilization properties. CONCLUSION: Pre‐sowing treatment of melon seeds carrying A. citrulli using nanosecond‐pulsed plasma technology can effectively control seedling BFB disease and promote melon seedling growth by optimizing DBD parameters. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Background Chilling stress is a key abiotic stress that severely restricts the growth and quality of melon (Cucumis melo L.). Few studies have investigated the mechanism of response to chilling stress in melon. Results We characterized the physiological, transcriptomic, and metabolomic response of melon to chilling stress using two genotypes with different chilling sensitivity (“162” and “13-5A”). “162” showed higher osmotic regulation ability and antioxidant capacity to withstand chilling stress. Transcriptome analysis identified 4395 and 4957 differentially expressed genes (DEGs) in “162” and “13-5A” under chilling stress, respectively. Metabolome analysis identified 615 and 489 differential enriched metabolites (DEMs) were identified in “162” and “13-5A” under chilling stress condition, respectively. Integrated transcriptomic and metabolomic analysis showed enrichment of glutathione metabolism, and arginine (Arg) and proline (Pro) metabolism, with differential expression patterns in the two genotypes. Under chilling stress, glutathione metabolism-related DEGs, 6-phosphogluconate dehydrogenase (G6PDH), glutathione peroxidase (GPX), and glutathione s-transferase (GST) were upregulated in “162,” and GSH conjugates (L-gamma-glutamyl-L-amino acid and L-glutamate) were accumulated. Additionally, “162” showed upregulation of DEGs encoding ornithine decarboxylase, Pro dehydrogenase, aspartate aminotransferase, pyrroline-5-carboxylate reductase, and spermidine synthase and increased Arg, ornithine, and Pro. Furthermore, the transcription factors (TFs), MYB, ERF, MADS-box, and bZIP were significantly upregulated, suggesting their crucial role in chilling tolerance of melon. Conclusions These findings elucidate the molecular response mechanism to chilling stress in melon and provide insights for breeding chilling-tolerant melon.

Abstract Background Melon (Cucumis melo L.), an important cucurbit crop, faces production limitations due to powdery mildew (PM). Developing resistant varieties offers a sustainable, genetics-based alternative to chemical treatments. Therefore, identifying PM resistance quantitative trait loci (QTL) and creating trait-associated markers are essential for efficient melon PM resistance improvement through marker-assisted backcrossing (MABC). Results Three F2 populations, A6, B2, and C4, were generated for QTL mapping of PM resistance. Major QTL were identified on chromosome 2 in A6, chromosome 5 in B2, and chromosomes 5 and 12 in C4. A series of TaqMan® assays targeting regions on chromosomes 2, 5, and 12 were developed and validated for foreground and recombinant selection, complemented by the double digest restriction-site associated DNA genotyping system to evaluate the recurrent parent genome recovery. Three MABC programs using resistant donor parents from A6 and C4 crossed with elite susceptible recurrent parents with green and orange fruit flesh were implemented. After two to three cycles of MABC, individual QTL was successfully introgressed into elite genetic backgrounds, giving six PM resistance lines in each green- and orange-fleshed background. PM inoculation on the twelve near-isogenic lines confirmed their resistance to PM. Conclusions We have identified major PM resistance QTL for melon on chromosomes 2, 5, and 12 and have introgressed individual QTL to elite genetic backgrounds using MABC in three and a half years. This study demonstrates the power of combining high-throughput genotyping with breeding efforts and showcases the efficiency of molecular breeding.

To elucidate the genetic factors contributing to melon resistance against Phelipanche aegyptiaca and comprehend the role of differentially resistant materials in responding to changes in P. aegyptiaca parasitisation, we investigated the P. aegyptiaca-resistant line K16 and the susceptible line K27. The parasitism rate of P. aegyptiaca was assessed at 25 days. Results revealed significant differences in parasitisation rates between K16 (15.35%) and K27 (34.2%). We compared inoculated K16 and K27 to their respective controls through transcriptome analysis and contrasted inoculated K16 with inoculated K27. Eight hundred eighteen genes exhibited differential expression across all comparisons. Gene ontology (GO) functional enrichment analysis revealed that differentially expressed genes were significantly enriched in nitrate transport and assimilation, cellular components, extracellular regions, binding and enzyme activities. KEGG pathway enrichment underscored the importance of phytohormone signaling, phenylpropanoid biosynthesis, linolenic acid and linoleic acid metabolism, cyanoamino acid metabolism and nitrogen metabolism in the interaction between melon and P. aegyptiaca. Nine genes potentially associated with P. aegyptiaca resistance were identified, encoding cytochrome protein P450, peroxidases, β-glucosidase, acyltransferase family proteins, histidine phosphotransfer protein, and D-type cyclins. This study aims to provide insights into the mechanism of P. aegyptiaca parasitism on melons and offers implications for breeding resistant varieties

Abstract Plant tendrils are specialized organs that can twine around other structures to facilitate climbing. They occur in a variety of plant families and have diverse ontogenic origins. In cucurbits, tendrils originate from lateral shoots. Fine mapping verified that the tendril-less ctl mutation of the melon Cucumis melo corresponds to a frameshift mutation in the CmTCP1 gene, which encodes a TCP transcription factor. A yeast two-hybrid screen for CmTCP1/CTL-interacting proteins identified a member of the plant-specific YABBY transcription factor family, which was named CmYAB1. Each of the N- and C-terminal regions of CmTCP1 interacted with CmYAB1. The ctl mutation impaired the interaction between CmTCP1 and CmYAB1. Both proteins interacted in vitro and were localized to the nucleus in plant cells. In situ expression analysis revealed the coexistence of the CmTCP1 and CmYAB1 mRNAs in the abaxial domains of developing tendrils. An RNA-seq analysis of the seven YABBY genes in the melon genome revealed relatively high expression ratios of CmYAB1 in tendrils compared with those in leaves. These results suggest a novel function of the YABBY protein through its interaction with a TCP protein in the development of cucurbit tendrils.

Seed size is an important agronomic trait in melons that directly affects seed germination and subsequent seedling growth. However, the genetic mechanism underlying seed size in melon remains unclear. In the present study, we employed Bulked-Segregant Analysis sequencing (BSA-seq) to identify a candidate region (~1.35 Mb) on chromosome 6 that corresponds to seed size. This interval was confirmed by QTL mapping of three seed size-related traits from an F2 population across three environments. This mapping region represented nine QTLs that shared an overlapping region on chromosome 6, collectively referred to as qSS6.1. New InDel markers were developed in the qSS6.1 region, narrowing it down to a 68.35 kb interval that contains eight annotated genes. Sequence variation analysis of the eight genes identified a SNP with a C to T transition mutation in the promoter region of MELO3C014002, a leucine-rich repeat receptor-like kinase (LRR-RLK) gene. This mutation affected the promoter activity of the MELO3C014002 gene and was successfully used to differentiate the large-seeded accessions (C-allele) from the small-seeded accessions (T-allele). qRT-PCR revealed differential expression of MELO3C014002 between the two parental lines. Its predicted protein has typical LRR-RLK family domains, and phylogenetic analyses reveled its similarity with the homologs in several plant species. Altogether, these findings suggest MELO3C014002 as the most likely candidate gene involved in melon seed size regulation. Our results will be helpful for better understanding the genetic mechanism regulating seed size in melons and for genetically improving this important trait through molecular breeding pathways.

Melon is an important cash crop grown worldwide, with China leading the world in melon acreage. Melon wilt is becoming more common as the area under melon cultivation gradually increases. Therefore, it is crucial to understand the resistance pattern of Fusarium wilt in melons. In this work, among the four test melon cultivars, YG was highly resistant to Fusarium wilt and 1455 was disease‐resistant. However, 5657 was susceptible, while 5455 was highly susceptible to the disease. We detected 71,852 differentially expressed genes in 16 combinations, including 37,382 with up‐regulation and 3470 with down‐regulation, and we investigated 11 genes associated with resistance to Fusarium wilt through bioinformatics and transcriptome analysis. We identified two differentially expressed cinnamyl alcohol dehydrogenases (CAD) that were down‐regulated in the susceptible melon material in contrast to the resistant variety. Nine chitinase (CHT) genes were differentially expressed, with four showing up‐regulation and four showing down‐regulation in the susceptible compared to the resistant melon material. The MeloCHT genes were located on chromosomes 2, 6, 8, 11 and 12, with four of them on chromosome 8. MeloCAD1 was located on chromosome 1 and MeloCAD2 on chromosome 8. The physicochemical properties of the encoded proteins were predicted by bioinformatics, including theoretical isoelectric point, instability coefficient, relative molecular mass, lipid solubility index and hydrophilicity index. The genes encode proteins with α‐helix, extended strand, random coils and β‐turns. This study provides fundamental knowledge on the transcriptome of melons and establishes a foundation for future research on the detection and application of Fusarium wilt‐resistant genes in melons. [ABSTRACT FROM AUTHOR]

Objective: To explore the relationship between the structure and composition of melon pericarp and its storability. Methods: We observed the surface and cross-sectional ultrastructure of the pericarp of six different melon varieties with different storage characteristics using scanning electron microscopy (SEM). The composition and antioxidant capacity of the pericarp were analyzed. Results: The wax content, the number of outer epidermis cell layers, cell arrangement and cuticle thickness of melon pericarp were closely correlated with fruit storability. There was a positive correlation between pericarp hardness and fruit storability. The polygalacturonase (PG) in the pericarp degrades the composition of the cell wall and consequently causes a decrease in the hardness of the pericarp, affecting the storability characteristics of the fruit. The antioxidant substances such as total polyphenols and flavonoids in the pericarp of different melon varieties, as well as the activities of antioxidant enzymes such as peroxidase (POD) and superoxide dismutase (SOD), affected their storability characteristics. Conclusion: Principal component analysis (PCA) showed that pericarp hardness, total pectin (TP) content, protopectin (PP) content, PG, pectin methylesterase (PME) and peroxidase (POD) activities had a significant impact on melon storability.

Objective: To investigate the changes of cell wall degrading enzyme activity and gene expression during the infection of postharvest melon fruit by Alternaria alternata, and to reveal the pathogenic mechanism of Alternaria alternata. Methods: Jiashi melon and 86-1 melon fruits were used as experimental materials. Alternaria alternata was inoculated and stored at room temperature (25 ℃) and relative humidity of 35%~40%. The diameter of lesions was measured, and the microstructure of lesions was observed. Pectin lyase (PL), cellulase (Cx), β-glucosidase (CB) and polygalacturonase (PG) were determined. The expression changes of AaPL, AaCx, AaPG and AaCB were analyzed by absolute quantitative method of fluorescence quantitative polymerase chain reaction (PCR), and the correlation between the activity of four cell wall degrading enzymes and the expression of their corresponding genes was analyzed. Results: Under the same infection days, the lesion diameter of 86-1 melon pulp and peel tissue was larger than that of Jiashi melon. The microstructure of the lesion tissue was observed. Compared with the two melons, A. alternata propagated faster in 86-1 melon cells and had a stronger ability to destroy the cell structure of 86-1 melon. The changes of activity and gene expression of four cell wall degrading enzymes on two melons were compared. Under the same number of days, the enzyme activity and gene expression were higher in the 86-1 melon inoculation group, and the number of days when the activity and expression reached the peak in the Jiashi melon inoculation group was later. Conclusion: During the infection process, due to the melon's own disease resistance mechanism, the change trend of cell wall degrading enzyme activity and gene expression fluctuated from 6 to 10 days. The infection ability of Alternaria alternata in 86-1 melon was stronger, which also reflected that Jiashi melon had stronger resistance to Alternaria alternata infection.

Abstract Background Ripeness is a phenotype that significantly impacts the quality of fruits, constituting a crucial factor in the cultivation and harvesting processes. Manual detection methods and experimental analysis, however, are inefficient and costly. Results In this study, we propose a lightweight and efficient melon ripeness detection method, MRD-YOLO, based on an improved object detection algorithm. The method combines a lightweight backbone network, MobileNetV3, a design paradigm Slim-neck, and a Coordinate Attention mechanism. Additionally, we have created a large-scale melon dataset sourced from a greenhouse based on ripeness. This dataset contains common complexities encountered in the field environment, such as occlusions, overlapping, and varying light intensities. MRD-YOLO achieves a mean Average Precision of 97.4% on this dataset, achieving accurate and reliable melon ripeness detection. Moreover, the method demands only 4.8 G FLOPs and 2.06 M parameters, representing 58.5% and 68.4% of the baseline YOLOv8n model, respectively. It comprehensively outperforms existing methods in terms of balanced accuracy and computational efficiency. Furthermore, it maintains real-time inference capability in GPU environments and demonstrates exceptional inference speed in CPU environments. The lightweight design of MRD-YOLO is anticipated to be deployed in various resource constrained mobile and edge devices, such as picking robots. Particularly noteworthy is its performance when tested on two melon datasets obtained from the Roboflow platform, achieving a mean Average Precision of 85.9%. This underscores its excellent generalization ability on untrained data. Conclusions This study presents an efficient method for melon ripeness detection, and the dataset utilized in this study, alongside the detection method, will provide a valuable reference for ripeness detection across various types of fruits.

Abstract The constant changes experienced in agricultural activities due to climate change pose a great challenge to melon production. Hence, this research examined the determinants of melon farmers’ adaptation strategies to cope with climate change hazards in southern–southern Nigeria. The research ultimately depended on primary data collected by using a set of questionnaires and interviews. The data were obtained from 260 samples retrieved from melon farmers by using multistage sampling techniques. The data were analyzed using the multivariate probit (MVP) model and partial eta squared test. The results of the MVP model showed that age (− 0.009), marital status (0.200), access to information on climate change (0.567) and crop insurance (0.214) were significant at the 0.01 level, while household size (− 0.030) was significant at the 0.05 level and determined the adoption of crop diversification. Educational level (0.012), extension contact (0.138) and access to credit (0.122) were significant at the 0.05 level, while access to information on climate change (0.415) was significant at the 0.01 level and determined the adoption of change in planting dates. Age (− 0.010) and access to information on climate change (0.381) were significant at the 0.01 level, while sex (− 0.139), marital status (0.158) and off-farm income (− 2.3E-7) were significant at the 0.05 level and determined the adoption of mixed farming. Farming experience (0.005) is significant at the 0.05 level, while access to information on climate change (0.529) and crop insurance (0.272) are significant at the 0.01 level and determine the adoption of drought-tolerant crop species. Access to information on climate change (0.536) is significant at the 0.01 level, indicating the adoption of improved crop species. Age (− 0.010), farm size (− 0.085) and crop insurance (0.206) were significant at the 0.05 level, while access to information on climate change (0.353) was significant at the 0.01 level and determined the adoption of off-farm job opportunities. The study recommends the availability and accessibility of credit, climate-smart agricultural practices, and the establishment of public‒private partnerships, among others.

Abstract Background Studies have shown that plant endophytic microbial communities are ubiquitous and closely related to plant growth and health. To clarify the mechanism of the melon varieties with high resistant to wilt, the endophytic microbial compositions and metabolites in roots of melon varieties with high resistant ability to wilt were analyzed. Results The results showed that the abundances of Firmicutes, Ascomycota, Bacillus, Bradyrhizobium, Amycolatopsis, Actinospica, and Catenulispora all increased in roots of wilt high resistant melon varieties (MT) which compared to wilt susceptible melon varieties (MS). Meanwhile, Ochrobactrum, Bordetella, Roseateles, Staphylococcus, Acidovorax, Amycolatopsis, Catenulispora, Promicromonospora, and Gymnopilus were the unique endophytic microbes in roots of MT. Moreover, in comparison with the MS varieties, the functions of Defense mechanisms, Secondary metabolites biosynthesis, transport and catabolism, Nucleotide transport and metabolism, Signal transduction mechanisms, Coenzyme transport and metabolism, Carbohydrate transport and metabolism and Amino acid transport and metabolism all increased in roots of MT varieties. Additionally, the nucleotide metabolism and biosynthesis of cofactors metabolic pathways were also significantly increased in roots of MT varieties. On the other hand, the untargeted metabolome results showed that Biosynthesis of various plant secondary metabolites, Nucleotide metabolism and Biosynthesis of cofactors metabolic pathways were significantly increased in the expression of MT varieties; and the content of metabolic compounds such as flavonoids, Cinnamic acid compounds, Organic acid compounds, and Nucleotides were increased. In addition, the correlation between microbiome and metabolome indicates a significant correlation between the two. Conclusions All above results suggested that higher abundant antagonistic microbes and metabolic functions of endophytes in roots of wilt high resistant melon varieties (MT) were the important mechanisms for their high resistance to wilt. Graphical Abstract

Abstract Background Phosphorus (P) deficiency, a major nutrient stress, greatly hinders plant growth. Phosphate (Pi) uptake in plant roots relies on PHT1 family transporters. However, melon (Cucumis melo L.) lacks comprehensive identification and characterization of PHT1 genes, particularly their response patterns under diverse stresses. Results This study identified and analyzed seven putative CmPHT1 genes on chromosomes 3, 4, 5, 6, and 7 using the melon genome. Phylogenetic analysis revealed shared motifs, domain compositions, and evolutionary relationships among genes with close histories. Exon number varied from 1 to 3. Collinearity analysis suggested segmental and tandem duplications as the primary mechanisms for CmPHT1 gene family expansion. CmPHT1;4 and CmPHT1;5 emerged as a tandemly duplicated pair. Analysis of cis-elements in CmPHT1 promoters identified 14 functional categories, including putative PHR1-binding sites (P1BS) in CmPHT1;4, CmPHT1;6, and CmPHT1;7. We identified that three WRKY transcription factors regulated CmPHT1;5 expression by binding to its W-box element. Notably, CmPHT1 promoters harbored cis-elements responsive to hormones and abiotic factors. Different stresses regulated CmPHT1 expression differently, suggesting that the adjusted expression patterns might contribute to plant adaptation. Conclusions This study unveils the characteristics, evolutionary diversity, and stress responsiveness of CmPHT1 genes in melon. These findings lay the foundation for in-depth investigations into their functional mechanisms in Cucurbitaceae crops.

Relevance. Due to climate change on the planet, it is becoming increasingly difficult to obtain high yields of melons and melons in rain-fed conditions. Therefore, it is necessary to develop modern methods of growing them. Accordingly, the use of new water-soluble fertilizers for the cultivation of melon in hot climates is a relevant work at the moment.Material and methodology. Objects of research: medium-ripening melon variety GP 599f and watersoluble fertilizers Lignohumate, Energen Extra, Zinc Sulfate. We have carefully studied options using these fertilizers for double foliar treatment of plants during the growing season.Results. As a result of studying new types of water-soluble fertilizers on increasing the vegetative mass of plants, yield and biochemical parameters of the variety sample, a positive effect was revealed. As a result of a comparative analysis of data on plant development after double treatment with the studied preparations, an increase in canes in all variants was noted in relation to the control by 4.3-18.7%. When calculating the yield in all studied options, an increase in these indicators was noted in relation to the option without treatments. After treating the plants with new types of fertilizers, the yield was 13.4-15.9 t/ha. The average fetal weight varied from 1.7 kg. up to 1.8 kg with maximum values in the Lignohumate and Energen Extra options. An analysis of the comparison of the biochemical composition of fruits showed that new types of fertilizers did not affect the taste and purity of the products. The dry matter content was noted to be 0.8-1% higher than the control variant. Nitrate levels in fruits did not exceed the maximum permissible concentration (90 mg/kg) and amounted to 24-28 mg/kg.

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tillage practices significantly influence crop yield and soil quality. This study investigated the impact of rotary tillage (RT) and deep tillage (DT) on soil properties, microbial diversity, and melon (Cucumis melo L.) root growth and yield. RT involved breaking up the topsoil to a depth of 15 cm using a rotary tiller, while DT employed a rotary tiller followed by a moldboard plow to turn the soil layer over to a depth of 35 cm. The melon variety "Nasimi" was used as the material. Our findings revealed a remarkable response of soil phosphorus to tillage practices. High-throughput sequencing results revealed a significant impact of tillage practices on the soil fungal composition, richness, and diversity but little impact on the bacterial communities. Compared to RT, DT markedly enhanced melon root length, root surface area, root volume, and mean root diameter by 47.42%, 56.70%, 58.83%, and 27.28%, respectively. Additionally, DT treatments significantly increased melon yield (53.46%) compared to RT. The results indicate that DT improves soil nutrient availability, affects soil fungal community characteristics, and optimizes root distribution in soil, thereby improving melon yield. The findings offer valuable theoretical insights for the implementation of effective tillage practices in open-field melon cultivation. [ABSTRACT FROM AUTHOR]

One of the plants that are widely cultivated in Indonesia is the melon plant. Commodity melon (Cucumis melo L.) is one of the horticultural crops that is spreading. Melon is a fruit that is widely consumed by Indonesian people. However, the productivity of melons in Indonesia is low when compared to other fruit crops. Utilization of high yielding varieties, managing the growing environment appropriately and applying proper cultivation techniques in order to increase or maintain melon production need to be done to overcome fluctuating production. In this study, morphological characterization of several candidate melon varieties was carried out which is useful for knowing different characters and having economic value. The research was conducted from July to October 2022 at the Glass House CV. Borneo Seed Indonesia which is located in Bocek Village, Karangploso District, Malang Regency, East Java. The design used in this study was a randomized block design with 8 treatments and 3 replications. If the calculated F results from the ANOVA table are significantly different, then proceed with further tests using the DMRT test with a level of 5%. The results showed that the candidate varieties that had the potential to have high yields and superior performance were the MO-04 and MO-07 candidates. The yield potential of the MO-04 variety candidate was on the character of fruit diameter, fruit length, percentage of fruit flesh that could be consumed, fruit weight, level of sweetness and shelf life. The yield potential of the MO07 variety candidate is on the character of fruit diameter, fruit length, percentage of fruit that can be consumed, fruit weight, productivity per hectare and level of sweetness. In addition, the candidate varieties MO-04 and MO-07 have special characteristics, namely flesh color and net density. [ABSTRACT FROM AUTHOR]

To investigate the genetic diversity of 40 melon and cantaloupe cultivars, which were collected from the central regions of Iran and southwestern Afghanistan, inter-simple sequence repeat (ISSR) primers and several morphological traits were used. The results demonstrate that 12 selected ISSR markers generated polymorphic bands with a distinct band pattern. There were a total of 150 bands created, with 95 bands exhibiting polymorphism (62.44% diversity). Based on shape and characteristics, cluster analysis and principal coordinate analysis (PCoA) classified the cultivars into five groups: winter and late ripening, medium ripening, sweet, and early melons, including cantaloupe and melon. In the majority of instances, PCoA was consistent with cluster analysis, whereas the molecular data did not perfectly match the morphological results. The results of the analysis classified the morphological characteristics of individuals into five groups: the first group comprised nine Iranian and Afghan melon genotypes with long, thin-skinned forms and intermediate medium ripening, and the second group comprised five Afghan melon genotypes with late ripening, winter ripe, and thick skin and flesh. The third group of 11 Iranian and Afghan melon cultivars was typically medium-sized, elliptical-shaped melons with thin skin. The fourth group consists of two Iranian melons with small seeds, small fruit, rapid maturation, and no flavor. The final group possessed dense and tender flesh, a spherical shape, and large seeds. In conclusion, morphological traits and ISSR analysis could be useful tools for classifying melon germplasm for future breeding applications. The morphological and molecular similarities between Afghan and Iranian cultivars suggest their origin. [ABSTRACT FROM AUTHOR]

Cucumis melo is an annual dicotyledonous trailing herb. It is fruity, cool, and refreshing to eat and is widely loved by consumers worldwide. The single fruit weight is an important factor affecting the yield, and thus the income and economic benefits, of melon crops. In this study, to identify the main QTLs (quantitative trait locus) controlling the single fruit weight of melon and thereby identify candidate genes controlling this trait, specific-locus amplified fragment sequencing (SLAF) analysis was performed on the offspring of female 1244 plants crossed with male MS-5 plants. A total of 115 individual plants in the melon F2 population were analyzed to construct a genetic linkage map with a total map distance of 1383.88 cM by the group in the early stages of the project, which was divided into 12 linkage groups with a total of 10,596 SLAF markers spaced at an average genetic distance of 0.13 cM. A total of six QTLs controlling single fruit weight (sfw loci) were detected. Seven pairs of markers with polymorphisms were obtained by screening candidate intervals from the SLAF data. The primary QTL sfw2.2 was further studied in 300 F2:3 family lines grown in 2020 and 2021, respectively, a positioning sfw2.2 between the markers CY Indel 11 and CY Indel 16, between 18,568,142 and 18,704,724 on chromosome 2. This interval contained 136.58 kb and included three genes with functional annotations, MELO3C029673, MELO3C029669, and MELO3C029674. Gene expression information for different fruit development stages was obtained from 1244 and MS-5 fruits on the 15d, 25d, and 35d after pollination, and qRT-PCR (quantitative reverse transcription–PCR) indicated that the expression of the MELO3C029669 gene significantly differed between the parents during the three periods. The gene sequences between the parents of MELO3C029669 were analyzed and compared, a base mutation was found to occur in the intronic interval between the parents of the gene, from A-G. Phylogenetic evolutionary tree analysis revealed that the candidate gene MELO3C029669 is most closely related to Pisum sativum Fimbrin-5 variant 2 and most distantly related to Cucumis melo var. makuwa. Therefore, it was hypothesized that MELO3C029669 is the primary major locus controlling single fruit weight in melon. These results not only provide a theoretical basis for further studies to find genes with functions in melon single fruit weight but also lay the foundation for accelerating breakthroughs and innovations in melon breeding. [ABSTRACT FROM AUTHOR]

Environmental cues profoundly influence the developmental processes of plants that evolve to produce specific phenotypes. However, the developmental plasticity in response to seasonal changes, particularly temperature and day length, has not been fully understood in fruit development and quality. To explore the mechanism by which the transcriptional network adapts to external environmental changes by regulating metabolism during the development of melon fruits, this study selected the fruits grown under spring and fall conditions and focused on specific phenylpropanoid pathway metabolites, including phenolic acids, lignin, and flavonoids. Significant changes in these compounds result in noticeable differences in fruit quality such as texture, flavor, and color, which are of utmost importance to consumers. Employing co-expression analysis complemented by machine learning, we identified hub genes and pathways governing the metabolic changes, highlighting the influence of temperature and photoperiod cues in mediating the transcriptional regulatory networks. These results provide valuable insights into how fruits adapt to seasonal variability, and drive us to innovate broadly adaptable melon cultivars poised for improved climate resilience in the future. [ABSTRACT FROM AUTHOR]

This study investigated nutrient and mineral compositions of elephant grass (Pennisetum purpureum) achara soup. All ingredients used in the soup preparation were sourced from Watt Market in Calabar, Cross River State, Nigeria. The study adopted experimental design. Standard procedures were employed at all steps of the experiment. A 9-point hedonic scale was used for sensory evaluation to rate the flavor, color, appearance, texture, and general acceptability. Findings nutrient contents reveal moisture 32.10g/100g; protein 22.50 g/100g; fat 34.10g/100g; fiber 2.80 g/100g; carbohydrate 4.74 g/100g; and ash 3.40 g/100g. Mineral composition of the soup include 0.013mg/100g for potassium, calcium 21.40mg/100g, magnesium 138.30mg/100g, iron 0.82mg/100g, and phosphorus 2.84 mg/100g. It was concluded that consumption of the soup can positively impact the nutritional status of individuals. Nutrient and mineral compositions of the soup can provide essential dietary components that can help address nutrition-related conditions. Encouraging increased consumption of this soup among communities may contribute to the reduction of malnutrition and associated health issues. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Ripeness is a phenotype that significantly impacts the quality of fruits, constituting a crucial factor in the cultivation and harvesting processes. Manual detection methods and experimental analysis, however, are inefficient and costly. Results: In this study, we propose a lightweight and efficient melon ripeness detection method, MRD-YOLO, based on an improved object detection algorithm. The method combines a lightweight backbone network, MobileNetV3, a design paradigm Slim-neck, and a Coordinate Attention mechanism. Additionally, we have created a large-scale melon dataset sourced from a greenhouse based on ripeness. This dataset contains common complexities encountered in the field environment, such as occlusions, overlapping, and varying light intensities. MRD-YOLO achieves a mean Average Precision of 97.4% on this dataset, achieving accurate and reliable melon ripeness detection. Moreover, the method demands only 4.8 G FLOPs and 2.06 M parameters, representing 58.5% and 68.4% of the baseline YOLOv8n model, respectively. It comprehensively outperforms existing methods in terms of balanced accuracy and computational efficiency. Furthermore, it maintains real-time inference capability in GPU environments and demonstrates exceptional inference speed in CPU environments. The lightweight design of MRD-YOLO is anticipated to be deployed in various resource constrained mobile and edge devices, such as picking robots. Particularly noteworthy is its performance when tested on two melon datasets obtained from the Roboflow platform, achieving a mean Average Precision of 85.9%. This underscores its excellent generalization ability on untrained data. Conclusions: This study presents an efficient method for melon ripeness detection, and the dataset utilized in this study, alongside the detection method, will provide a valuable reference for ripeness detection across various types of fruits. [ABSTRACT FROM AUTHOR]

SUMMARY: FLAGELLIN SENSING 2 (FLS2) encodes a pattern recognition receptor that perceives bacterial flagellin. While putative FLS2 orthologs are broadly conserved in plants, their functional characterization remains limited. Here, we report the identification of orthologs in cucumber (Cucumis sativus) and melon (C. melo), named CsFLS2 and CmFLS2, respectively. Homology searching identified CsFLS2, and virus‐induced gene silencing (VIGS) demonstrated that CsFLS2 is required for flg22‐triggered ROS generation. Interestingly, genome re‐sequencing of melon cv. Lennon and subsequent genomic PCR revealed that Lennon has two CmFLS2 haplotypes, haplotype I encoding full‐length CmFLS2 and haplotype II encoding a truncated form. We show that VIGS‐mediated knockdown of CmFLS2 haplotype I resulted in a significant reduction in both flg22‐triggered ROS generation and immunity to a bacterial pathogen in melon cv. Lennon. Remarkably, genomic PCR of CmFLS2 revealed that 68% of tested commercial melon cultivars possess only CmFLS2 haplotype II: these cultivars thus lack functional CmFLS2. To explore evolutionary aspects of CmFLS2 haplotype II occurrence, we genotyped the CmFLS2 locus in 142 melon accessions by genomic PCR and analyzed 437 released sequences. The results suggest that CmFLS2 haplotype II is derived from C. melo subsp. melo. Furthermore, we suggest that the proportion of CmFLS2 haplotype II increased among the improved melo group compared with the primitive melo group. Collectively, these findings suggest that the deleted FLS2 locus generated in the primitive melo subspecies expanded after domestication, resulting in the spread of commercial melon cultivars defective in flagellin recognition, which is critical for bacterial immunity. [ABSTRACT FROM AUTHOR]

Tomato leaf curl New Delhi virus (ToLCNDV) is a begomovirus causing significant melon (Cucumis melo) crop losses globally. This study aims to map the ToLCNDV resistance in the PI 414723 melon accession, previously identified and characterized through phenotypic studies, thereby exploring shared genomic regions with the established resistant source WM-7. In the present study, WM-7 and PI 414723 were crossed with the susceptible accessions 'Rochet' and 'Blanco' respectively, to generate F1 hybrids. These hybrids were self-pollinated to generate the populations for mapping the ToLCNDV resistance region and designing markers for marker-assisted selection. Disease evaluation included visual symptom scoring, viral-load quantification and tissue printing. Genotyping-by-sequencing and SNP markers were used for quantitative trait loci (QTL) mapping. For genetic analysis, qPCR and bulked segregant RNA-seq (BSR-seq) were performed. Gene expression was assessed using RNA-seq, and qRT-PCR was used for confirmation. The research narrows the candidate region for resistance in WM-7 and identifies overlapping QTLs on chromosome 11 in PI 414723, found in the region of the DNA primase large subunit. BSR-seq and expression analyses highlight potential regulatory roles of chromosome 2 in conferring resistance. Differential expression was confirmed for six genes in the candidate region on chromosome 2. This study confirms the existence of common resistance genes in PI 414723 and WM-7. [ABSTRACT FROM AUTHOR]

Nitrogen is the primary nutrient for plants. Low nitrogen generally affects plant growth and fruit quality. Melon, as an economic crop, is highly dependent on nitrogen. However, the response mechanism of its self-rooted and grafted seedlings to low-nitrogen stress has not been reported previously. Therefore, in this study, we analyzed the transcriptional differences between self-rooted and grafted seedlings under low-nitrogen stress using fluorescence characterization and RNA-Seq analysis. It was shown that low-nitrogen stress significantly inhibited the fluorescence characteristics of melon self-rooted seedlings. Analysis of differentially expressed genes showed that the synthesis of genes related to hormone signaling, such as auxin and brassinolide, was delayed under low-nitrogen stress. Oxidative stress response, involved in carbon and nitrogen metabolism, and secondary metabolite-related differentially expressed genes (DEGs) were significantly down-regulated. It can be seen that low-nitrogen stress causes changes in many hormonal signals in plants, and grafting can alleviate the damage caused by low-nitrogen stress on plants, ameliorate the adverse effects of nitrogen stress on plants, and help them better cope with environmental stresses. [ABSTRACT FROM AUTHOR]

Begomoviral diseases in cucurbits have been observed in Baja California Sur (BCS), Mexico recurrently since the 2017 detection of the Squash leaf curl virus (SLCuV) in squash. Two years later, samples of symptomatic plants were collected in three arid agricultural regions, where the most frequently observed symptoms were chlorosis, reduced leaf size, stunting and severe leaf deformation, observed mainly on squash and cantaloupe. The mean incidence of begomovirus-like symptoms differed among cucurbits, with 20% in cucumber, 28% in cantaloupe, 30% in watermelon and 50% in squash. Samples were tested by polymerase chain reaction for begomovirus infection with degenerate primers, and later the virus identities were confirmed by specific primer pairs. All symptomatic cucurbit samples tested positive for SLCuV, and in a second analysis of these previously tested samples, squash, and cantaloupe samples tested positive for Cucurbit leaf crumple virus (CuLCrV). Thus, these samples showed a mixed CuLCrV/SLCuV infection. Pairwise identity analysis of the DNA-A component of the viruses indicated the presence of CuLCrV at 99%, and SLCuV at 99.1%. Recombination analyses between these viruses were negative, indicating that they belong to well-defined phylogenetic groups. Additionally, the 5´-TGGTGTCC-3´ iteron was consistently observed in all SLCuV and CuLCrV variants, including in other close species of the SLCuV clade. However, an additional iteron was observed in CuLCrV-BCS that is not in the Arizona and California variants, indicating that more studies are needed to elucidate the role of the additional iteron and the importance of CuLCrV/SLCuVSLCV mixed infection in emerging viruses in Mexico and other parts of the world. [ABSTRACT FROM AUTHOR]

In cold-sensitive products, low temperatures lead to chilling injuries. Under chilling stress conditions, the production of reactive oxygen species increases and causes oxidative stress. Plants have developed an efficient antioxidant defense system to prevent the accumulation and elimination of reactive oxygen species. With the aim of investigating the antioxidant activity of melons under low temperature conditions, seven melon genotypes including 4 parents (Abadan, Khatouni, Dudaim and Japan) and 3 hybrids (Khatouni×Abadan, Dudaim×Khatoni and Japan× Khatouni) were cultivated in the Horticultural Science Research Center, University of Tehran, Karaj, in the years 2018 and 2019. After harvesting, the fruits were kept at three temperatures (1, 4 and 13° C) for thirty days. The results of the research showed that the firmness of the tissue and the total soluble solids were higher in the samples of Japan and Japan×Khatouni genotypes compared to other melons. Also, Japan and Japan×Khatouni genotypes showed the lowest chilling index (10% and 8% respectively) after thirty days. The lowest firmness and soluble solids and the highest malondialdehyde content was found in Dudaim×Khatouni genotype and the highest chilling index (45%) was seen in Khatouni × Abadan genotype. The amount of activity of antioxidant enzymes (catalase, peroxidase and superoxide dismutase) was higher in melons that had a lower chilling index. The highest activity of antioxidant enzymes was seen in Japan and Japan×Khatouni genotypes. It seems that the elevated levels of catalase, peroxidase, and superoxide dismutase enzymes contribute to improving cold resistance in these samples of melon. Japan and Japan×Khatouni are recommended as genotypes with high durability and shelf life (up to 30 days) at low temperatures conditions. [ABSTRACT FROM AUTHOR]

Microbial agents such as the Bacillus species are recognized for their role as biocontrol agents against various phytopathogens through the production of diverse bioactive compounds. This study evaluates the effectiveness of Bacillus subtilis PE7 in inhibiting the growth of Didymella bryoniae, the pathogen responsible for gummy stem blight (GSB) in cucurbits. Dual culture assays demonstrate significant antifungal activity of strain PE7 against D. bryoniae. Volatile organic compounds (VOCs) produced by strain PE7 effectively impede mycelial formation in D. bryoniae, resulting in a high inhibition rate. Light microscopy revealed that D. bryoniae hyphae exposed to VOCs exhibited abnormal morphology, including swelling and excessive branching. Supplementing a potato dextrose agar (PDA) medium with a 30% B. subtilis PE7 culture filtrate significantly decreased mycelial growth. Moreover, combining a 30% culture filtrate with half the recommended concentration of a chemical fungicide yielded a more potent antifungal effect than using the full fungicide concentration alone, inducing dense mycelial formation and irregular hyphal morphology in D. bryoniae. Strain PE7 was highly resilient and was able to survive in fungicide solutions. Additionally, B. subtilis PE7 enhanced the nutrient content, growth, and development of melon plants while mitigating the severity of GSB compared to fungicide and fertilizer treatments. These findings highlight B. subtilis PE7 as a promising biocontrol candidate for integrated disease management in crop production. [ABSTRACT FROM AUTHOR]

Background: As an important global agricultural cash crop, melon has a long history of cultivation and a wide planting area. The physiological metabolism of melon after harvest is relatively strong; if not properly stored, melon is easily invaded by external pathogens during transportation, resulting in economic losses and greatly limiting its production, development and market supply. Therefore, the storage and freshness of melon are the main challenges in realizing the annual supply of melon, so postharvest storage has received increasing amounts of attention from researchers. Methods: This study used academic, PubMed, and Web of Science resources to retrieve keywords related to postharvest storage and melon quality; read, refined, classified, and sorted the retrieved literature; sorted and summarized the relevant research results; and finally completed this article. Results: This article reviews the mechanism and effects of physical, chemical and biological preservation techniques on the sensory quality, compound contents and respiratory physiological activities of different varieties of melon fruits. When maintaining normal metabolism and not producing physiological disorders, melon inhibits cell wall metabolism, reactive oxygen species metabolism and the ethylene biosynthesis pathway, etc., to the greatest extent during postharvest storage, thereby reducing the material consumption of fruits, delaying the ripening and senescence process, and prolonging the postharvest life and shelf life. Conclusion: The literature provides a theoretical basis for postharvest preservation technology in the melon industry in the future and provides corresponding guidance for the development of the melon industry. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The quality of melon is often associated to physicochemical properties and phytonutrient accumulation. The determination of optimum harvest time and selection of genotype are important for maximising the health benefits for melon consumers. The goal of the present work was to study the changes of physicochemical, bioactive compounds, and antioxidant activity of five muskmelon cultivars (Maazoun, Galaoui, Stambouli, Trabelsi, and Asli) at three ripening stages (unripe, ripe, and overripe). The main antioxidant compounds namely carotenoid, total phenol, flavonoid, and vitamin C content were measured. The hydrophilic and lipophilic antioxidant activity (HAA and LAA, respectively) analyses and their correlation with functional compounds were also performed. The result showed that the ripening stage significantly influenced the melon fruit quality depending on cultivars. The transition from the unripe to the overripe melon led to an increase in pH, °Brix, carotenoids, and phenols in all cultivars, except for Stambouli and Trabelsi, where the °Brix value decreased. The levels of flavonoids (except Maazoun, Stambouli, and Asli), vitamin C, HAA, and LAA (except Stambouli) reached a peak at the ripe stage, and decreased thereafter. At the ripe stage, the orange flesh colour melon Galaoui was distinguished by a higher level of carotenoid (54.28 mg/kg fw), phenolic (1290 mg GAE/kg fw), flavonoid (400.12 mg RE/kg fw), vitamin C contents (197.56 mg/kg fw), as well as a higher hydrophilic and lipophilic antioxidant activity (296.77 and 155.82 μM Trolox/100 g fw, respectively). A significant correlation between hydrophilic antioxidant activity and phenolic contents was found (r = 0.98, p < 0.01), suggesting that phenolics were the major contributors to the hydrophilic antioxidant capacity. These findings highlighted the effect of genetic factor and ripeness in determining the physicochemical properties, phytonutrient accumulation, and antioxidant potential of melon fruit. Melon fruits examined can be considered a promising source of functional compounds and antioxidant potential, in both ripe and overripe stages. [ABSTRACT FROM AUTHOR]

The constant changes experienced in agricultural activities due to climate change pose a great challenge to melon production. Hence, this research examined the determinants of melon farmers' adaptation strategies to cope with climate change hazards in southern–southern Nigeria. The research ultimately depended on primary data collected by using a set of questionnaires and interviews. The data were obtained from 260 samples retrieved from melon farmers by using multistage sampling techniques. The data were analyzed using the multivariate probit (MVP) model and partial eta squared test. The results of the MVP model showed that age (− 0.009), marital status (0.200), access to information on climate change (0.567) and crop insurance (0.214) were significant at the 0.01 level, while household size (− 0.030) was significant at the 0.05 level and determined the adoption of crop diversification. Educational level (0.012), extension contact (0.138) and access to credit (0.122) were significant at the 0.05 level, while access to information on climate change (0.415) was significant at the 0.01 level and determined the adoption of change in planting dates. Age (− 0.010) and access to information on climate change (0.381) were significant at the 0.01 level, while sex (− 0.139), marital status (0.158) and off-farm income (− 2.3E-7) were significant at the 0.05 level and determined the adoption of mixed farming. Farming experience (0.005) is significant at the 0.05 level, while access to information on climate change (0.529) and crop insurance (0.272) are significant at the 0.01 level and determine the adoption of drought-tolerant crop species. Access to information on climate change (0.536) is significant at the 0.01 level, indicating the adoption of improved crop species. Age (− 0.010), farm size (− 0.085) and crop insurance (0.206) were significant at the 0.05 level, while access to information on climate change (0.353) was significant at the 0.01 level and determined the adoption of off-farm job opportunities. The study recommends the availability and accessibility of credit, climate-smart agricultural practices, and the establishment of public‒private partnerships, among others. [ABSTRACT FROM AUTHOR]

Background: Studies have shown that plant endophytic microbial communities are ubiquitous and closely related to plant growth and health. To clarify the mechanism of the melon varieties with high resistant to wilt, the endophytic microbial compositions and metabolites in roots of melon varieties with high resistant ability to wilt were analyzed. Results: The results showed that the abundances of Firmicutes, Ascomycota, Bacillus, Bradyrhizobium, Amycolatopsis, Actinospica, and Catenulispora all increased in roots of wilt high resistant melon varieties (MT) which compared to wilt susceptible melon varieties (MS). Meanwhile, Ochrobactrum, Bordetella, Roseateles, Staphylococcus, Acidovorax, Amycolatopsis, Catenulispora, Promicromonospora, and Gymnopilus were the unique endophytic microbes in roots of MT. Moreover, in comparison with the MS varieties, the functions of Defense mechanisms, Secondary metabolites biosynthesis, transport and catabolism, Nucleotide transport and metabolism, Signal transduction mechanisms, Coenzyme transport and metabolism, Carbohydrate transport and metabolism and Amino acid transport and metabolism all increased in roots of MT varieties. Additionally, the nucleotide metabolism and biosynthesis of cofactors metabolic pathways were also significantly increased in roots of MT varieties. On the other hand, the untargeted metabolome results showed that Biosynthesis of various plant secondary metabolites, Nucleotide metabolism and Biosynthesis of cofactors metabolic pathways were significantly increased in the expression of MT varieties; and the content of metabolic compounds such as flavonoids, Cinnamic acid compounds, Organic acid compounds, and Nucleotides were increased. In addition, the correlation between microbiome and metabolome indicates a significant correlation between the two. Conclusions: All above results suggested that higher abundant antagonistic microbes and metabolic functions of endophytes in roots of wilt high resistant melon varieties (MT) were the important mechanisms for their high resistance to wilt. [ABSTRACT FROM AUTHOR]

Background: Phosphorus (P) deficiency, a major nutrient stress, greatly hinders plant growth. Phosphate (Pi) uptake in plant roots relies on PHT1 family transporters. However, melon (Cucumis melo L.) lacks comprehensive identification and characterization of PHT1 genes, particularly their response patterns under diverse stresses. Results: This study identified and analyzed seven putative CmPHT1 genes on chromosomes 3, 4, 5, 6, and 7 using the melon genome. Phylogenetic analysis revealed shared motifs, domain compositions, and evolutionary relationships among genes with close histories. Exon number varied from 1 to 3. Collinearity analysis suggested segmental and tandem duplications as the primary mechanisms for CmPHT1 gene family expansion. CmPHT1;4 and CmPHT1;5 emerged as a tandemly duplicated pair. Analysis of cis-elements in CmPHT1 promoters identified 14 functional categories, including putative PHR1-binding sites (P1BS) in CmPHT1;4, CmPHT1;6, and CmPHT1;7. We identified that three WRKY transcription factors regulated CmPHT1;5 expression by binding to its W-box element. Notably, CmPHT1 promoters harbored cis-elements responsive to hormones and abiotic factors. Different stresses regulated CmPHT1 expression differently, suggesting that the adjusted expression patterns might contribute to plant adaptation. Conclusions: This study unveils the characteristics, evolutionary diversity, and stress responsiveness of CmPHT1 genes in melon. These findings lay the foundation for in-depth investigations into their functional mechanisms in Cucurbitaceae crops. [ABSTRACT FROM AUTHOR]