Search Results (75)

A yellow leaf mutant named ‘ZT00091’ was discovered during the cultivation of the melon variety ‘ZT091’. An analysis of the leaf ultrastructure revealed that the chloroplasts of ‘ZT00091’ were significantly smaller than those of ‘ZT091’, with irregular shapes, blurred contours, and no starch granules. Metabolomic analysis revealed 792 differentially abundant metabolites between ‘ZT00091’ and ‘ZT091’, with 273 upregulated and 519 downregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results indicated that the differentially abundant metabolites were enriched mainly in the carotenoid pathway. qRT-PCR was used to analyze key genes in the carotenoid pathway of melon. Compared with those in ‘ZT091’, the genes promoting carotenoids and lutein in ‘ZT00091’ were significantly upregulated, which may explain the yellow color of ‘ZT00091’ leaves. Significant differences in the chlorophyll contents (chlorophyll a, chlorophyll b, and total chlorophyll) and carotenoid contents were found between ‘ZT00091’ and ‘ZT091’, indicating that the yellowing of melon leaves is related to changes in the carotenoid and chlorophyll contents. This study provides a theoretical basis for research on the molecular mechanism of melon yellowing. Full article

Fruit shape diversity in melon is governed by complex genetic networks, with ethylene biosynthesis playing a pivotal yet poorly characterized role. In this study, we identified a rare CmACS7^{A57V/frameshift} double mutant through fine mapping of the fsq2 locus. Ethylene-mediated ovary growth regulation has been completely lost in the CmACS7^{A57V/frameshift} double mutant, driving a transition from elongated to spherical fruit. Transcriptome analysis was performed to clarify the core role of CmACS7 in the ethylene signaling pathway. The loss of CmACS7 function regulates key genes in the ethylene responsive factor, cytokinin signaling pathway, and auxin-related genes, resulting in an imbalance in hormone levels. This imbalance directly affects the coordination of cell proliferation and expansion and ultimately determines the fruit morphology. A genetic diversity analysis of public melon germplasm resources indicated that while the CmACS7^{A57V/frameshift} mutation accounts for only 0.5% of the germplasm, it is strongly correlated with the round fruit phenotype and is important for breeding in Xinjiang. The results of this study suggest that CmACS7^{A57V/frameshift} could be used as a molecular marker to accelerate the breeding of melon varieties with excellent fruit morphology and, at the same time, reveal the coevolutionary significance of this gene in the domestication of Cucurbitaceae crops. Full article

One of the world’s most sustainable solutions is to replace fossil-based polymers with biopolymers. The production of xanthan gum can be optimized using various renewable and cost-effective raw materials, which is a key focus in industrial biotechnology. Xanthan gum is a bioengineered thickening, stabilizing, and emulsifying agent. It has unique properties for use in many industries (food, biotechnology, petrochemicals, agricultural, cosmetics, wastewater treatment) and medical applications. It is tasteless, environmentally safe, non-toxic, and biodegradable. The biotechnological production of xanthan gum depends on several factors: bacterial strain development, culture medium preparation, carbon sources, fermentation parameters and modes, pH, temperature, recovery, purification, and quality control regulations. Bio-innovative strategies have been developed to optimize the production of xanthan gum. A variety of carbon and nitrogen sources, as well as alternative renewable sources, have been used in the production of xanthan gum. The aim of the present study was to optimize the xanthan gum yield using Xanthomonas campestris bacteria and different carbon (D-glucose, D-sorbitol, lactose, sucrose, D-mannitol, D-fructose, erythritol, coconut palm sugar, L-arabinose, unrefined cane sugar), various nitrogen (bacterial peptone, casein peptone, L-glutamic acid, L-arginine, L-methionine, L-tryptophan, malt extract, meat extract, L-phenylalanine, soy peptone) and alternative carbon (orange peels, tangerine peels, lemon peels, avocado peels, melon peels, apple peels, cellulose, xylose, xylitol) sources. The xanthan gum samples were analyzed using antioxidant methods. Our study showed that using L-glutamic acid as the carbon source for 72 h of bacterial fermentation of Xanthomonas campestris resulted in the highest xanthan gum yield: 32.34 g/L. However, using renewable resources, we achieved a very high concentration of xanthan gum in just 24 h of fermentation. According to the reducing power and DPPH methods, the highest antioxidant activities were measured for xanthan gum whose biosynthesis was based on renewable resources. Xanthan gum structures have been verified by FT-IR and ¹H NMR analysis. The sustainable biotechnology study has the advantage of increasing the sustainable production of xanthan gum by using renewable alternative resources compared to other production processes. Xanthan gum continues to be a valuable biopolymer with a wide range of industrial applications while promoting environmentally friendly production practices. Full article

The accurate identification of melon seed varieties is essential for improving seed purity and the overall quality of melon production. In this study, hyperspectral imaging was used to identify six varieties of melon seeds. Both hyperspectral images and RGB images were generated during hyperspectral image acquisition. The spectral features of seeds were extracted from the hyperspectral images. The image features of the corresponding seeds were manually extracted from the RGB images. Five different datasets were formed using the spectral features and RGB images of the seeds, including seed spectral features, manually extracted seed image features, seed images, the fusion of seed spectral features with manually extracted features, and the fusion of seed spectral features with seed images. Logistic Regression (LR), Support Vector Classification (SVC), and Extreme Gradient Boosting (XGBoost) were used to establish classification models using spectral features and the manually extracted image features. Convolutional Neural Network (CNN) models were established using the five datasets. The results indicated that the CNN models achieved good performance in all five datasets, with classification accuracies exceeding 90% for the training, validation, and test sets. Also, CNN using the fused datasets obtained optimal performance, achieving classification accuracies exceeding 97% for the training, validation, and test sets. The results indicated that both spectral features and image features can be used to identify the six varieties of melon seeds, and their fusion of spectral features and image features can improve classification performance. These findings provide an alternative approach for melon seed variety identification, which can also be extended to other seed types. Full article

In this study, the melon variety ‘Da Shetou’ was used as the test material, and pot cultivation was employed with soil collected from Da’an City to investigate the effects of biochar addition on melon yield and quality, rhizosphere soil physicochemical properties, and soil microbial community. The experiment was set up with five treatments: saline–alkali soil (B0), 1% biochar and 99% saline–alkali soil (B1), 3% biochar and 97% saline–alkali soil (B3), 5% biochar and 95% saline–alkali soil (B5), and 7% biochar and 93% saline–alkali soil (B7). This study found that the addition of 3% biochar increased the fruit yield of melons. Compared to the control, the soil bulk density was reduced by 4.99%, 8.66%, 1.77%, and 7.71% under the 1%, 3%, 5%, and 7% biochar treatments, respectively. Biochar addition increased organic matter, alkaline-hydrolyzable nitrogen, available phosphorus, and available potassium concentrations in the rhizosphere soil. Additionally, the total nitrogen, salt concentration, and exchangeable sodium percentage were also reduced. Compared to the B0 treatment, the concentrations of K⁺, Ca²⁺, and Mg²⁺ increased to varying degrees across different treatments, while the concentrations of Na⁺ and Cl⁻ decreased. The relative abundance of dominant bacterial phyla in the soil varied across different treatments. The dominant bacterial phyla included Proteobacteria, Actinobacteriota, Acidobacteriota, and a total of 10 others. The dominant fungal phyla included Ascomycota, Basidiomycota, Mortierellomycota, and a total of seven others. Redundancy analysis (RDA) identified key drivers. Available potassium in the rhizosphere soil of melons was the dominant factor influencing bacterial community composition at the phylum level. Soil bulk density, exchangeable sodium percentage, and total nitrogen were identified as the dominant factors influencing fungal community composition at the phylum level. This study confirmed that 3% biochar application synergistically regulated nutrient cycling and microbial functional groups, thereby enhancing yield of thin-skinned melons (yield increase: 45.22%). Full article

This study aimed to investigate the correlation between salt tolerance during the germination and seedling stages in melons by analyzing 10 melon varieties under NaCl stress during germination and seedling stages. We found that 200 mM is the appropriate concentration for screening salt-tolerant germplasm in melons. Salt stress led to a decline in germination and seedling growth parameters, while antioxidant enzyme activities and osmotic substance contents significantly increased. Specifically, the activities of CAT and SOD increased by up to 27.22-fold and 6.35-fold, respectively, and soluble protein and proline contents increased by up to 1.03-fold and 1.05-fold, respectively. Varietal differences in salt tolerance traits were observed. Correlation and principal component analyses revealed that 6 germination indicators could be consolidated into 1 comprehensive indicator, accounting for 79.225% of the variance, while 16 seedling-stage indicators were reduced to 3 comprehensive indicators, with a cumulative contribution rate of 75.089%. Membership function and cluster analyses categorized the 10 varieties into 3 groups at both stages, identifying ‘Xindongfangmi’ and ‘Jinyuliuxing’ as salt-tolerant varieties. Additionally, a significant positive correlation (r = 0.834) was found between the comprehensive membership function values of germination and seedling stages. These results provide a scientific basis for assessing melon salt tolerance, indicating that germination-stage salt tolerance may predict seedling-stage salt tolerance. By utilizing PCA, comprehensive evaluation, and cluster analysis of relevant indicators under salt stress during the germination period of melon, the salt tolerance of the seedling stage can be quickly identified. The implementation of rapid salt tolerance screening at the germination stage can facilitate the selection of salt-tolerant germplasm and the development of salt-tolerant melon varieties. Full article

The Hami melon is a characteristic economic crop in Xinjiang. Long-term storage at low temperatures can cause cold damage and significantly impact the storage quality of Hami melon fruits. This study investigated the cold resistance of two Hami melon varieties under low temperatures, screened key genes, and further explored their resistance mechanisms. By comparing and analyzing the relationship between phenotypic morphology, physiological indicators, and storage time, it was found that the symptoms of cold damage in Hami melons are related to both storage time and variety. To analyze the response mechanisms of Hami melons to cold stress at the molecular level, we conducted transcriptome sequencing analysis on the cold-sensitive Hami melon variety Gold Queen and the cold-resistant variety Jia Shi. The analysis shows that cold stress induces the expression of these differentially expressed genes, which participate in the AsA-GSH cycling system, form the NADPH-P450 pathway, and establish the ERF-WRKY cold resistance pathway. This, in turn, increases the content of free proline in the fruits, clears denatured proteins within the fruit, maintains the stability of the redox system, and inhibits certain differentially expressed genes that regulate cell wall metabolism, thereby alleviating fruit softening and improving cold resistance. Full article

In recent years, increasing attention in regional and national markets has been given to the Puglia region’s traditional landraces of unripe melon (Cucumis melo L.). However, distinguishing these landraces is challenging due to their significant variability. A detailed morphological characterization is crucial to identify the unique features of each variety, while also assessing their productive potential. This study evaluated nine Puglia landraces of C. melo: ‘Barattiere’, ‘Carosello leccese’, ‘Carosello scopatizzo’, ‘Cucumbr di Martina Franca’, ‘Carosello di Polignano’, ‘Carosello striato tondo di Massafra’, ‘Spuredda bianca’, ‘Spuredda nera’, and ‘Spuredda fasciata’. The aims of the work were to identify specific and distinctive characters for these landraces, subdivided into traditional macro-groups (“Barattiere”, “Caroselli”, and “Spuredde”), and to evaluate productive and quality traits that could be interesting for future commercial promotion. The main findings revealed distinct characteristics among the “Barattiere” group and the other two macro-groups across all the parameters considered. The differentiation of the “Caroselli” and “Spuredde” macro-groups, on the other hand, was more challenging because of similar intragroup characteristics. In particular, a case of synonymy was found between the landraces ‘Carosello leccese’ and ‘Spuredda bianca’, and a high degree of dissimilarity was identified between ‘Carosello di Polignano’ and the other landraces. Full article

Melon fruit cracking reduces yield, increases transportation costs, and shortens shelf life, which makes the development of cracking-resistant varieties crucial for the industry’s advancement. This study investigated the pathways and genes related to melon fruit cracking through cell morphology observation, endogenous hormone analyses, and transcriptome analysis of two contrasting advanced inbred lines, the extremely crack-resistant line R2 and the crack-susceptible line R6. R2 has small, tightly packed epidermal cells with a thick cuticle, while R6 has larger, more loosely arranged epidermal cells and a significantly thinner cuticle. Hormonal analysis revealed significant differences in abscisic acid, cytokinin, gibberellin, auxin, and salicylic acid contents between R2 and R6 at various fruit developmental stages. The abscisic acid and salicylic acid content in R2 were 1.9–5.2 times and 1.5–3.6 times higher than those in R6, respectively, whereas the gibberellin content in R6 was 1.5–2.3 times higher than that in R2. Pericarp transcriptome analysis identified 4281, 6242, and 6879 differentially expressed genes (DEGs) at 20, 30, and 40 days after anthesis, respectively. Among these, 47 DEGs related to phenylpropanoid biosynthesis (ko00940) and 79 DEGs involved in plant hormone signal transduction (ko04075) were differentially expressed at two or more stages. WGCNA analysis identified six core hub genes that potentially play a role in regulating melon fruit cracking. These findings lay a foundation for further studies on the functional roles of crack-resistant genes and the breeding of crack-tolerant varieties. Full article

The present study aimed to investigate the occurrence of eight potentially toxic elements (PTEs) in selected varieties of watermelon (Citrullus lanatus var. Arka Shyama and Crimson Sweet) and muskmelon (Cucumis melo var. Cantaloupe and Kajri) grown near riverbanks in the Yamuna and Ganga River basins of Northern India. For this purpose, samples of melon fruits were collected from ten sampling sites from May to June 2024 and analyzed using ICP-OES. The results showed that the levels of PTEs varied significantly across the sampling sites, with muskmelons exhibiting slightly higher concentrations compared to watermelons. Specifically, the concentration (mg/kg dry weight) ranges for the watermelon varieties were Cd (0.05–0.20), Cr (0.40–1.10), Cu (1.50–4.90), Pb (0.01–0.11), As (0.01–0.08), Fe (80.00–120.00), Mn (9.00–15.80), and Zn (5.00–18.00). For muskmelons, the ranges were Cd (0.05–0.23), Cr (0.40–1.00), Cu (2.40–4.80), Pb (0.01–0.08), As (0.02–0.08), Fe (80.00–120.00 g), Mn (9.00–15.00), and Zn (8.00–18.00). In particular, the variability coefficients (CV%) indicated differential contamination in Crimson Sweet. On the other hand, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) tools facilitated the identification of sites of significant contamination and their respective interactions. The health risk studies using the health risk index (HRI), dietary intake modeling (DIM), and the target hazard quotient (THQ) also revealed no significant health risk of eight PTEs in melon fruits. Therefore, this study provides valuable insights into the biomonitoring of PTE contamination in widely consumed summer fruits of Northern India and the subsequent health risk assessment. Full article

To screen out the bio-control soil microorganisms for preventing melon wilt, soil microbial compositions in rhizospheres between wilt-resistant and susceptible melon varieties were analyzed. The results showed that the soil fungal richness in rhizospheres of wilt-resistant melon varieties (MT) was significantly higher than that of wilt-susceptible melon varieties (MS). Additionally, in comparison with MS, soil bacterial compositions, such as Proteobacteria, Bacteroidota, Acidibacter, Streptomyces, etc., and the soil fungal compositions, such as Penicillium, Derxomyces, Aspergillus, and Talaromyces, enriched; also, Trichoderma, Gibellulopsis, and Pseudallescheria decreased in rhizospheres of wilt-resistant melon varieties (MT). Moreover, Mycothermus, Zopfiella, and Cladorrhinum were the unique soil-dominant fungal genera in rhizospheres of MT. All the above results suggested that the soil bacterial communities, such as Proteobacteria, Bacteroidota, Acidibacter, Streptomyces, etc., and the soil fungal communities, such as Penicillium, Derxomyces, Aspergillus, Talaromyces Mycothermus, Zopfiella, and Cladorrhinum, could be speculated as the potential soil bio-control microorganisms for preventing melon wilt. Full article

Melon (Cucumis melo L.) is a significant cash crop globally and is cherished for its sweet and flavorful fruits, as well as its high nutritional values. However, its yield and quality are limited by various factors, including drought, salinity, and low temperatures. Low temperatures are one of the primary factors influencing the growth and development of melons, diminishing the viability, germination, and growth rate of melon seeds. Concurrently, low temperatures also reduce light absorption efficiency and fruit yields, thereby affecting melon growth and development. Serine hydroxymethyltransferase (SHMT), a conserved phosphopyridoxal-dependent enzyme, plays a crucial role in plant resistance to abiotic stressors. In this study, eight CmSHMT family genes were identified from the melon genome. We predicted their chromosomal locations, physicochemical properties, gene structures, evolutionary relationships, conserved motifs, cis-acting elements of promoters, and tissue-specific expression patterns. The expression levels of CmSHMT family genes in response to low-temperature stress was then analyzd using qRT-PCR. The phylogenetic results indicated that these CmSHMT genes were classified into four subfamilies and were unevenly distributed across five chromosomes, with relatively high conservation among them. Furthermore, our investigation revealed that the promoter regions of the CmSHMT family genes contain many cis-acting elements related to phytohormones, growth, and various stress responses. The relative expression levels of CmSHMT3, CmSHMT4, CmSHMT6, and CmSHMT7 were higher under low-temperature stress compared to the control group. Notably, the promoter region of CmSHMT3 contains cis-acting elements associated with low-temperature response (LTR) and abscisic acid response (ABRE). It is suggested that the mechanism through which CmSHMT3 responds to low-temperature stress treatments may be associated with hormonal regulation. These findings provide a foundation for the further exploration of CmSHMT family genes in melon and their functional roles in response to low-temperature stress, and they provide a theoretical basis for the targeted breeding of superior melon varieties with enhanced tolerance to low temperatures. Full article

Fruits and vegetables are sources of natural nutraceuticals. They contain a variety of bioactive compounds such as vitamins, minerals, dietary fibers and other phytochemicals that contribute to their health-promoting properties and disease prevention. A wide variety of fruits and vegetables should be eaten to ensure that an individual’s diet includes a combination of phytonutraceuticals and to obtain all their health benefits. This study aimed to compare the antioxidant potential and cardiovascular benefits within a restricted sample of ten fruits and ten vegetables, previously reported as largely consumed in Portugal. With data available from the literature, antioxidant potential scales were established. Additionally, a set of seven criteria, including high antioxidant capacity (FRAP values above 1), presence of n-3 fatty acids, saturated fat, cholesterol, trans fatty acids, fiber and sodium was used to create comparative scales of their potential cardiovascular benefits. The main results showed that the fruits that simultaneously exhibited the highest antioxidant potential values and the highest cardiovascular potential benefit were lemon, grapes, and melon; among vegetables, the top rankings were found to be tomato and onion. These products have been recognized as interesting sources of natural nutraceuticals for the food and pharmaceutical industries. In the future, similar approaches are desirable to translate complex scientific data into practical, simple and user-friendly information for food literacy initiatives, including nutrition education materials, about the relative level of the potential cardiovascular benefits of a wide diversity of food products. Full article

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. Full article

Bacterial fruit blotch (BFB) is a devastating disease caused by Acidovorax citrulli, severely impacting the watermelon and melon industries and leading to significant economic losses. Currently, researchers have not identified any commercial melon varieties with high resistance to BFB, and farmers primarily rely on chemical agents for prevention and control. However, the extensive use of these agents contributes to increased drug resistance among pathogenic bacteria, making it essential to develop environmentally friendly control methods. To explore the feasibility of combining the Bacillus velezensis ZY1 strain with chemical agents for BFB management, we assessed the efficacy of 10 bactericides and the ZY1 strain against Acidovorax citrulli. The results show that Prothioconazole, Zhongsheng Tetramycin Solution, Streptomycin Sesquisulfate, Tetramycin, Zhongshengmycin, and ZY1 exhibited significant inhibitory effects on the growth of Acidovorax citrulli. We determined the biocompatibility of the bactericides with the ZY1 strain using the plate confrontation method and the flat counting method. Zhongsheng Tetramycin Solution, Zhongshengmycin, and Kasugamycin exhibited good compatibility with the ZY1 strain. Additionally, we established the optimal compounding ratio of the bactericide and ZY1 using the Horsfall method. Among these, Zhongshengmycin demonstrated the best performance when combining its efficacy against Acidovorax citrulli with its biocompatibility with the ZY1 strain. The combination of Zhongshengmycin and ZY1 at a volume ratio of 5:5 significantly inhibited Acidovorax citrulli, exhibiting a clear synergistic effect with a synergy index (I_R) value of 1.542. Field tests conducted over 21 days in Beijing greenhouses, Hainan Field facility greenhouses, and Xinjiang showed that the control efficacy of the Zhongshengmycin and ZY1 combination (89.23%) significantly surpassed that of the single agent Zhongshengmycin (80.35%) and the biocontrol bacterium ZY1 (72.12%). Notably, the application rate of Zhongshengmycin in the mixture was only half that of the single agent, resulting in a significant reduction in chemical usage. The combination of Bacillus velezensis ZY1 and Zhongshengmycin not only decreases chemical usage but also significantly enhances control efficacy compared to using Zhongshengmycin alone. Full article