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The growing demand for essential nutrients provided by fruits has led to an increase in processed fruit products. However, this processing generates a significant amount of byproducts. Due to a lack of awareness about their nutritional and health benefits, these byproducts are often treated as waste, negatively impacting the environment. To address this, this review focuses on the potential health effects and industrial reusability of these byproducts and their bioactive compounds from commonly consumed fruits in the United States including apples, bananas, citrus, and watermelon. The reviewed studies showed that these by-products, including peels, seeds, pomace, skin, and rinds, are rich sources of bioactive compounds at higher concentrations than the fruit flesh, offering potential health benefits including antioxidant, antibacterial, antidiabetic, anti-obesity, immunomodulatory, anticancer, and anti-inflammatory properties. Incorporation of these byproducts in foods improved their physicochemical and nutrition properties as they are rich in dietary fiber and polyphenols. While many studies show promising results in vitro and in animal models, further research is needed to understand their effectiveness in humans and their potential for sustainable food innovation. [ABSTRACT FROM AUTHOR]

Root regeneration is an important factor influencing the healing rate of graft union and the survival of double-root-cutting grafting. To date, little information is available on how to enhance root regeneration of rootstock in grafted watermelon (Citrullus lanatus) seedlings. In this study, the effects of different light treatments on root regeneration were determined. This revealed that addition of far-red light (Fr) could significantly expedite root formation in the rootstock. Moreover, the results of transcriptome analysis revealed that plant hormone pathway and auxin-related genes were greatly induced by Fr, especially for auxin-response proteins (including CmIAA11, CmIAA17, and CmAUX28), Small auxin-up RNA genes (including CmSAUR20 and CmSAUR50) and the auxin efflux transporter (CmPIN3). In addition, the expression of Phytochrome Interacting Factor (PIFs), such as CmPIF1, CmPIF3 and CmPIF7, was remarkably increased by Fr. These genes may act together to activate auxinrelated pathways under Fr treatment. Based on the results of HPLC-MS/MS analysis, the concentrations of different auxin-types in adventitious root were significantly influenced by Fr. Furthermore, the better growth of rootstock root displayed superior vasculature transport activity of the graft union with Fr treatment, which was determined by the acid magenta dyeing experiment. Therefore, all the results suggested that Fr could induce AR formation in rootstocks, which may be associated with the auxin accumulation by regulating the transcriptional level of auxin-related and PIF genes. The findings of this study demonstrated a practicable way to shorten the healing period of graftings and improve the quality of grafted watermelon seedlings, which will provide a theoretical basis for the speeding development of industrialized seedlings production. [ABSTRACT FROM AUTHOR]

Watermelon (Citrullus lanatus Thumb) is a significant vegetable crop globally and is prone to anthracnose disease caused by Colletotrichum spp. The use of chemical fungicides for managing crop diseases has adverse impacts on the environment and human health. Therefore, it is important to use biocontrol agents for disease management. In this study, streptomycetes were assessed as a potential biocontrol agent against anthracnose pathogen, Colletotrichum orbiculare WEC2. The potent Streptomyces sp. isolate WAB2 was isolated from healthy watermelon plants and showed remarkable antifungal efficacy against C. orbiculare WEC2. Rigorous assays confirmed its performance against C. orbiculare WEC2. Bioactive compounds produced by Streptomyces sp. isolate WAB2 were identified using Gas Chromatography–Mass Spectrometry (GC–MS). An SEM study indicated the parasitic action of Streptomyces sp. isolate WAB2 against the pathogen. The formulated talc-based product of Streptomyces sp. isolate WAB2 was effective when applied as a seed treatment + foliar spray against C. orbiculare WEC2 under pot culture conditions. These treatments reduced the disease incidence (31.81%) and exhibited a higher disease reduction (52.56%), compared to the untreated control. Therefore, treatment with talc-based Streptomyces sp. isolate WAB2 is a sustainable solution for anthracnose disease management, and it facilitates eco-friendly crop protection practices against the disease in watermelon. RESEARCH HIGHLIGHTS: Isolated streptomycete strains from healthy watermelon plants and screened for its efficacy against the pathogen, Colletotrichum orbiculare WEC2. Streptomyces sp. isolate WAB2 showed significant antifungal activity against the pathogen. Bio-active compounds produced by Streptomyces sp. isolate WAB2 was identified by Gas Chromatography–Mass Spectrometry (GC–MS). Using scanning electron microscopy (SEM), the parasitic activity of Streptomyces sp. isolate WAB2 against the pathogen was detected. Developed a talc-based formulation of Streptomyces sp. isolate WAB2 and tested it as a seed treatment plus foliar spray, effectively reducing the disease incidence. Graphical abstract illustrating the isolation and characterisation of Streptomyces sp. isolate WAB2 for the management of anthracnose pathogen (Colletotrichum orbiculare WEC2) in Watermelon. Antagonistic potential of Streptomyces sp. isolate WAB2 against Colletotrichum orbiculare: [ABSTRACT FROM AUTHOR]

In order to provide theoretical basis for the promotion and use of fish protein package fertilizer on watermelon ‘8848 Sweet King’, the effects of fish protein package fertilizer on the vegetative growth, quality, yield and benefit of watermelon were studied. The results showed that the application of fish protein package fertilizer could promote the growth of watermelon, improve the quality, yield and benefit of watermelon, and the experimental results reached significant differences. After combined with brassicin, the effect was more significant, which could increase the plant height by 13. 83%, the stem diameter by 10. 89%, the sugar content by 10. 85%, the VC content by 60. 00%, the income by 54 930 yuan/hm², and the input-output ratio by 1 ∶ 5. 94. In summary, during the whole growth period of watermelon, fish protein package fertilizer could be vigorously promoted, especially when combined with brassicin, the effect of increasing production, improving quality and increasing income was more significant. [ABSTRACT FROM AUTHOR]

This research was carried out with the aim of identifying the content of phytochemical compounds of alkaloids, flavonoids, tannins and saponins in the acetone extract of seedless red watermelon rind (Citrullus vulgaris), knowing the results of evaluating the physical properties of the acetone extract gel of seedless red watermelon rind (Citrullus vulgaris) with niacinamide against various concentrations of moisturizing gel preparations, and comparing the best moisture test concentration on acetone extract gel preparations of seedless red watermelon rind (Citrullus vulgaris) in providing optimal results. This research is a laboratory study of the experimental formulation of acetone extract of seedless red watermelon rind (Citrullus vulgaris) to determine the formulation and concentration of the best extract produced. The research results showed that acetone extract from the white skin of red seedless watermelon (Citrullus vulgaris) contained phytochemical compounds alkaloids, flavonoids, and polyphenol as well as lycopene in the white skin of red seedless watermelon (Citrullus vulgaris). The results of the evaluation of the physical properties of the acetone extract gel of seedless red watermelon rind (Citrullus vulgaris) in the negative control, 2.5% concentration, 5% concentration, and 7.5% concentration met the test requirements but did not meet the spreadability test requirements. And the best concentration of water content test in the acetone extract gel preparation of seedless red watermelon rind (Citrullus vulgaris) in providing optimal results is found in the gel preparation with a concentration of 7.5%. [ABSTRACT FROM AUTHOR]

To address the difficulties in manual counting for the uneven distribution and severe occlusion of watermelons in natural environments, this study utilizes drones and smartphones to collect videos and images, combined with manual annotation to establish a dataset for Sanbai melons and Ningxia selenium sand melons. A watermelon video automatic counting method based on the YOLOv7-GCSF model and an improved DeepSORT algorithm is proposed. The lightweight YOLOv7 model with GhostConv is enhanced with GBS modules, G-ELAN modules, and G-SPPCSPC modules to increase the model’s detection speed. Some ELAN modules are replaced with the C2f module from YOLOv8 to reduce redundant information. The SimAM attention mechanism is introduced into the MP module of the feature fusion layer to construct the MP-SimAM module, which is used to enhance the model's feature extraction capability. The CIoU loss function is replaced with the fasterconverging, lower-loss Focal EIoU loss function to increase the model's convergence speed. In video tracking and counting, a mask collision line mechanism is proposed for more accurate counting of Sanbai melons and Ningxia selenium sand melons. The results show that in terms of object detection: the four improvements to the YOLOv7-GCSF model have all enhanced the model’s performance to some extent. Specifically, compared to the YOLOv7 model, the construction of the MP-SimAM module increased accuracy by 1.5 percentage points, indicating a greater focus on Sanbai melons and Ningxia selenium sand melons. The addition of GhostConv reduced the model size by 28.1MB, demonstrating that the construction of GBS, G-ELAN, and G-SPPCSPC modules effectively reduced the model size and improved detection speed. The incorporation of the C2f module reduced the model's floating-point operations (FLOPs) by 77.5 billion, indicating that the model has eliminated most of the redundant information. The addition of the Focal EIoU loss function significantly increased the model’s convergence speed, indicating further enhancement of the model's learning ability. The improved YOLOv7-GCSF model achieved an accuracy (P) of 94.2% and a mean average precision (mAP0.5) of 98.2%, which is 5.0, 2.3, 21.9, and 14.9 percentage points higher in accuracy and 3.7, 0.3, 4.6, and 9.3 percentage points higher in mean average precision compared to YOLOv5, YOLOv7, Faster RCNN, and SSD, respectively. In terms of model lightweighting, the YOLOv7-GCSF model has seen a decrease of 1.18M and 0.11M in the number of parameters compared to the YOLOv4-Ghostnet and YOLOv7-Slimneck models, respectively. Compared to the original YOLOv7, the YOLOv7-GCSF model has reduced the parameter count and model size by 0.57M and 18.88MB, respectively. In terms of object tracking: the improved DeepSORT multi-object tracking accuracy is 91.2%, and the multi-object tracking precision is 89.6%, which is 5.0 and 13.7 percentage points higher in tracking accuracy and 3.7 and 13.1 percentage points higher in tracking precision compared to Tracktor and SORT, respectively. Comparing the improved model with manual counting results, the determination coefficient for the counting results of Sanbai melons and Ningxia selenium sand melons is 0.93, the average counting accuracy is 96.3%, and the average absolute error is 0.77, indicating that the error between the improved model and manual counting is small. This approach, by enabling effective counting of watermelons in agricultural fields, provides a technical methodology for the forecasting of watermelon yields. [ABSTRACT FROM AUTHOR]

Rind thickness (RT) is an important agronomic trait in watermelon [Citrullus lanatus (Thunb.) Mansf.] and affects watermelon storability. However, genetic studies on this trait, as well as gene regulation studies, are scarce and of limited production significance. We constructed a temporary F2 generation using the highly differentiated thick-rind watermelon 'XiaoXiGua-4' and the thin-rind watermelon 'DuanMan' as parents and localized the Cla97C02G044120 gene, which controls the thickness of watermelon rind, to the intervals of chromosome 2, CL2-32303995 and CL2-32316840, through 2 years of genetic analysis. No exonic mutations were found in this gene, but two promoter mutations resulted in changes in the promoter progenitor. Fluorescence quantitative PCR analysis revealed highly significant differences in expression at 1 d and 28 d, and the expression was significantly lower in thick-skinned watermelon varieties. Marker-assisted selection (MAS) for this trait was performed using the Caps marker CL2-32303995 and the InDel marker CL2-32316840, which not only verified the stability of the localization interval but also distinguished thick rind from thin rind. These results can be used for germplasm resource screening and have strong breeding significance. [ABSTRACT FROM AUTHOR]

Leaves are vital organs for photosynthesis, gas exchange, and light energy absorption in plants and play a crucial role in synthesizing essential nutrients. Watermelon is a widely cultivated crop worldwide and has a range of leaf shapes, including non-lobed (entire), semi-lobed, and highly lobed varieties. However, few studies have focused on lobed leaf traits in watermelons. Therefore, our study aimed to elucidate the genetic basis of leaf lobing regulation in watermelons, focusing on lines cultivated in Korea. We analyzed the F2 progeny derived from crosses between the highly lobed SIT463ST and the non-lobed PS137 watermelon line. We discovered that lobed leaf traits in watermelons are controlled by a single incomplete dominant gene. Additionally, we used next-generation sequencing-based bulked segregant analysis sequencing to identify a candidate genomic region spanning 24.06–24.09 Mb (25 kb) on Chr. 4. Three single nucleotide polymorphism markers (LL-4-238, LL-4-956, and LL-4-252) were developed that were closely associated with the non-lobed leaf margin shape in the F2 population. Analysis of the expression levels of these genes in the fine mapping region revealed only synonymous substitutions in the coding regions, suggesting that mutations in potential promoter regions may regulate gene expression, thereby affecting leaf morphology. These findings provide valuable insights into the molecular factors underlying non-lobed leaf traits in watermelons and offer potential targets for genetic improvement. [ABSTRACT FROM AUTHOR]

Watermelon (Citrullus spp.) is an economically important crop globally, but it is susceptible to various diseases, including powdery mildew. Previous studies have identified genetic factors associated with powdery mildew resistance. However, further research using diverse genetic approaches is necessary to elucidate the underlying genetic mechanisms of this resistance. In this study, the germplasm collection comprising highly homozygous inbred lines was employed, which enabled the accumulation of consistent data and improved the reliability of the genome-wide association study (GWAS) findings. Our investigation identified two significant single-nucleotide polymorphisms (SNPs), pm2.1 and pm3.1, which were strongly associated with disease resistance. Moreover, several candidate genes were revealed within the linkage disequilibrium (LD) blocks surrounding the significant SNPs. In conclusion, the identification of significant SNPs and their additive effects, combined with the discovery of relevant candidate genes, expanded our understanding of the genetic basis of disease resistance and can pave the way for the development of more resilient watermelon cultivars through marker-assisted selection. [ABSTRACT FROM AUTHOR]

Pectin is a vital component of plant cell walls and its methylation process is regulated by pectin methylesterase inhibitors (PMEIs). PMEIs regulate the structural and functional modifications of cell walls in plants and play an important role in plant processes such as seed germination, fruit ripening, and stress response. Although the PMEI gene family has been well characterized in model plants, the understanding of its molecular evolution and biological functions in watermelon remains limited. In this study, 60 ClPMEI genes were identified and characterized, revealing their dispersion on multiple chromosomes. Based on a systematic developmental analysis, these genes were classified into three subfamilies, which was further supported by the exon, intron, and conserved motif distribution. Analysis of cis-elements and expression patterns indicated that ClPMEIs might be involved in regulating the tolerance of watermelon to various abiotic stresses. Moreover, distinct ClPMEI genes exhibit specific functions under different abiotic stresses. For example, ClPMEI51 and ClPMEI54 showed a significant upregulation in expression levels during the late stage of drought treatments, whereas ClPMEI3 and ClPMEI12 displayed a significant downregulation under low-temperature induction. Subcellular localization prediction and analysis revealed that the ClPMEI family member proteins were localized to the cell membrane. This study provided an important foundation for the further exploration of the functions of ClPMEI genes in watermelon. [ABSTRACT FROM AUTHOR]

This experiment used floral buds from watermelon genic male sterile dual-purpose lines as materials to explore the differentially expressed miRNAs (DEMs) between male fertile and sterile floral buds of watermelon. Paraffin sectioning technology was employed for a cytological analysis, and small RNA sequencing was used to explore miRNAs related to anther or pollen development. Cytological analysis indicated that the abnormal development of tapetal cells may cause microspore abortion. Small RNA sequencing identified a total of 314 miRNAs (29 known and 285 novel, which belonged to 12 and 61 miRNA families, respectively) in floral buds. Differential expression revealed 36 (5 known and 31 novel) DEMs between male fertile and sterile buds, 7 and 29 of which were up-regulated and down-regulated, respectively. Target genes analysis showed that the 36 DEMs were predicted to target 577 genes, and these targets might participate in various biological processes, such as response to metal ions, floral organ development, stamen development, anther development, pollen maturation, and programmed cell death. Moreover, pathway analysis indicated that these genes were mainly enriched in purine metabolism, starch and sucrose metabolism, RNA transport, and other pathways. In addition, the 55 miRNA–target modules, including 3 known and 16 novel miRNAs with 30 target genes, might be related to anther or pollen development in watermelon. Our findings provide important miRNA–target modules related to watermelon anther or pollen development and can lay the foundation for biological functional analysis. [ABSTRACT FROM AUTHOR]

Watermelon production has rapidly increased in Morocco over the last 15 years. Since its independence in 1956, Morocco has promoted the production of early-season fruits and vegetables for European supermarkets to boost the national economy and improve rural livelihoods. Today, the expansion of watermelon production in arid regions of the country has had profound impacts on local land and water resources. In Zagora, a pre-Sahara oasis region in the southeast of the country, watermelons have contributed to the overuse of aquifers, trapping farmers in cycles of accumulating debt, and increasing conflict over land. Drawing on interviews and participant observation with residents and officials from 2021-2023, this paper demonstrates how a pastoral community embraced watermelon production in an effort to engage with the agro-export sector that drives the country's agricultural growth. Yet rather than contributing to the overall development of the region, watermelon production has deepened gender and economic disparities within the community and privileged a small group of farmers with access to capital. Although authorities restricted watermelon production in 2023, larger investors simply moved production, leaving small farmers to confront the volatile market while trying to sustain land, water, and collective identity in the region. [ABSTRACT FROM AUTHOR]

The peel stripe margin pattern is one of the most important quality traits of watermelon. In this study, two contrasted watermelon lines [slb line (P1) with a clear peel stripe margin pattern and GWAS-38 line (P2) with a blurred peel stripe margin pattern] were crossed, and biparental F2 mapping populations were developed. Genetic segregation analysis revealed that a single recessive gene is modulating the main-effect genetic locus (Clcsm) of the clear stripe margin pattern of peel. Bulked segregant analysis-based sequencing (BSA-Seq) and fine genetic mapping exposed the delimited Clcsm locus to a 19.686-kb interval on chromosome 6, and the Cla97C06G126680 gene encoding the MYB transcription factor family was identified. The gene mutation analysis showed that two non-synonymous single-nucleotide polymorphism (nsSNP) sites [Chr6:28438793 (A-T) and Chr6:28438845 (A-C)] contribute to the clear peel stripe margin pattern, and quantitative real-time polymerase chain reaction (qRT-PCR) also showed a higher expression trend in the slb line than in the GWAS-38 line. Further, comparative transcriptomic analysis identified major differentially expressed genes (DEGs) in three developmental periods [4, 12, and 20 days after pollination (DAP)] of both parental lines. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses indicated highly enriched DEGs involved in metabolic processes and catalytic activity. A total of 44 transcription factor families and candidate genes belonging to the ARR-B transcription factor family are believed to regulate the clear stripe margin trait of watermelon peel. The gene structure, sequence polymorphism, and expression trends depicted significant differences in the peel stripe margin pattern of both parental lines. The ClMYB36 gene showed a higher expression trend for regulating the clear peel stripe margin of the slb line, and the ClAPRR5 gene depicted a higher expression for modulating the blurred peel stripe margin in the GWAS-38 line. Overall, our fine genetic mapping and transcriptomic analysis revealed candidate genes differentiating the clear and blurred peel stripe patterns of watermelon fruit. [ABSTRACT FROM AUTHOR]

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Background: The KT/HAK/KUP is the largest K+ transporter family in plants, playing crucial roles in K+ absorption, transport, and defense against environmental stress. Sweet watermelon is an economically significant horticultural crop belonging to the genus Citrullus, with a high demand for K+ during its growth process. However, a comprehensive analysis of the KT/HAK/KUP gene family in watermelon has not been reported. Results: 14 KT/HAK/KUP genes were identified in the genomes of each of seven Citrullus species. These KT/HAK/KUPs in watermelon were unevenly distributed across seven chromosomes. Segmental duplication is the primary driving force behind the expansion of the KT/HAK/KUP family, subjected to purifying selection during domestication (Ka/Ks < 1), and all KT/HAK/KUPs exhibit conserved motifs and could be phylogenetically classified into four groups. The promoters of KT/HAK/KUPs contain numerous cis-regulatory elements related to plant growth and development, phytohormone response, and stress response. Under K+ deficiency, the growth of watermelon seedlings was significantly inhibited, with cultivated watermelon experiencing greater impacts (canopy width, redox enzyme activity) compared to the wild type. All KT/HAK/KUPs in C. lanatus and C. amarus exhibit specific expression responses to K+-deficiency and drought stress by qRT-PCR. Notably, ClG42_07g0120700/CaPI482276_07g014010 were predominantly expressed in roots and were further induced by K+-deficiency and drought stress. Additionally, the K+ transport capacity of ClG42_07g0120700 under low K+ stress was confirmed by yeast functional complementation assay. Conclusions: KT/HAK/KUP genes in watermelon were systematically identified and analyzed at the pangenome level and provide a foundation for understanding the classification and functions of the KT/HAK/KUPs in watermelon plants. [ABSTRACT FROM AUTHOR]

Members of the Cucurbitaceae family, which includes species with quite different characteristics, have been used for food, medicine, and ornamental purposes for a long time. However, most plant diseases and pests cause yield and quality losses in cucurbits, and one of the most important of these diseases is zucchini yellow mosaic virus (ZYMV), which one of the most common potyviruses worldwide and causes serious yield losses in cucurbit production worldwide. Zucchini Yellow Mosaic Virus shows symptoms such as yellowing, mottling, curling, deformation, mosaic, shortening and thickening of the internodes, and may also cause loss of yield and quality. As widely known, there is no effective chemical control of viral diseases, and the use of resistant or tolerant varieties is the most effective solution. In this study, 92 watermelon genotypes, 14 zucchinis (pumpkin seeds) and 29 ornamental pumpkins collected from different parts of Türkiye were tested against ZYMV. Symptoms of ZYMV in different watermelon genotypes and pumpkins were observed for 21 days. Genotypes showing systemic infection after inoculation were evaluated on a scale of 0-5. Also, RT-PCR studies were carried out on selecting nine symptomless control plants, seven ZYMV-sensitive genotypes showing 5-scale value, one genotype with 1-scale value considered tolerant, and one genotype belongs to C. lanatus var. citroides. According to the results, it was determined that some watermelon and ornamental pumpkin genotypes could be considered as tolerant. Watermelon, which was having accession number PI560016, was found resistant to Turkish local strain of ZYMV. Although different susceptibility levels were detected between watermelon genotypes, all pumpkin genotypes were discovered to be susceptible to the Turkish local strain of ZYMV. [ABSTRACT FROM AUTHOR]

Watermelon (Citrullus lanatus) is a plant that is widely cultivated by the community. The seedless watermelon is an F1 hybrid watermelon resulting from a cross between a diploid male watermelon and a tetraploid female watermelon. The low number of seeds produced by tetraploid watermelons is a problem at the seed producer level. This study aims to study the appearance and formation of tetraploid characters in fruits resulting from combinations of diploidtetraploid crosses. This research was conducted in August – November 2020 in Pamekasan, Madura. The design used was a Sigle Plot Design using the single plant method, using 2 F1 genotypes (diploid x tetraploid), 1 backcross genotype ((diploid x tetraploid) x tetraploid), 1 diploid genotype, 1 tetraploid genotype. 2 genotypes of F1 and 1 genotype of backcross were treated with selfing, cross with diploid, and cross with tetraploid so that 9 treatments were obtained. The results showed that the watermelon genotype used was diploid based on the observed fruit characters, namely fruit weight, fruit diameter, dkin thickness, flesh thickness, and number of seeds. The character of skin colour and fruit flesh colour follows their parents. [ABSTRACT FROM AUTHOR]

Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera®, Gavina®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators. [ABSTRACT FROM AUTHOR]

Watermelon is a highly cultivated fruit crop renowned for its quality properties of fruit flesh. Among various quality factors, fruit flesh firmness is a crucial quality parameter influencing the fruit texture, shelf life and its commercial value. The auxin/indole-3-acetic acid (Aux/IAA) plays a significant role in fruit development and ripening of non-climacteric fruits. However, the regulatory mechanism of Aux/IAA in controlling fruit flesh firmness and ripening in watermelon remains unknown. In this study, we employed an integrative approach combining genome-wide association study (GWAS) and bulked segregant RNA-Seq analysis (BSR-Seq) to identify an overlapping candidate region between 12 776 310 and 12 968 331 bp on chromosome 6, underlying an auxin-responsive gene (Aux/IAA) associated with flesh firmness in watermelon. Transcriptome analysis, followed by real-time quantitative reverse transcription PCR (qRT-PCR), confirmed that the expression of Aux/IAA was consistently higher in fruits with high flesh firmness. The sequence alignment revealed a single base mutation in the coding region of Aux/IAA. Furthermore, the concomitant Kompetitive/Competitive allele-specific PCR (KASP) genotyping data sets for F2 population and germplasm accessions identified Aux/IAA as a strong candidate gene associated with flesh firmness. Aux/IAA was enriched in the plant hormone signal transduction pathway, involving cell enlargement and leading to low flesh firmness. We determined the higher accumulation of abscisic acid (ABA) in fruits with low flesh firmness than hard flesh. Moreover, overexpression of Aux/IAA induced higher flesh firmness with an increased number of fruit flesh cells while reducing ABA content and flesh cell sizes. Additionally, the allelic variation in Aux/IAA for soft flesh firmness was found to exist in Citrullus mucosospermus and gradually fixed into Citrullus lanatus during domestication, indicating that soft flesh firmness was a domesticated trait. These findings significantly enhanced our understanding of watermelon fruit flesh firmness and consequently the watermelon fruit quality. [ABSTRACT FROM AUTHOR]

The general objective of this study was to evaluate response of selected watermelon growth and yield attributes to pig manure in Owerri, South Eastern Nigeria. Specifically, it determined response of watermelon to four rates of pig manure in terms of number of leaves produced per plant, vine length per plant, number of fruits harvested per plant and weight of fruits harvested per plant. The field experiments were conducted in 2020 and 2021 cropping seasons in the Teaching and Research Farm, Agricultural Science Department, Alvan Ikoku Federal University of Education, Owerri, Imo State, Nigeria. The investigation was carried out in a Randomized Complete Block Design with three replications. Treatments were composed of pig manure rates of 0, 5, 10, 15 tons per hectare. Parameters studied were number of leaves per plant, vine length per plant, number of fruits harvested per plant and weight of harvested fruits per plant. Data were subjected to Analysis of Variance (ANOVA) test and significant treatment means were separated using Least Significant Difference (LSD) protocol. Results obtained from the two experiments conducted show plants that received application of pig manure at the rate of 15 tons per hectare were outstanding in terms of vine length at 4weeks after planting (79.96 cm in 2020 and 58.93cm in 2021 ), 6 weeks after planting ( 162.46cm in 2020 and 89.73cm in 2021 ) and 8 weeks after planting (201.36cm in 2020 and 187.06 cm), number of leaves at 4 weeks after planting(25.50 in 2020 and 33.96 in 2021), 6 weeks after planting (28.50 in 2020 and 39.63 in 2021), 8 weeks after planting (31.10 in 2020 and 42.96 in 2021), number of fruits ( 4 fruits/plant in 2020 and 6 fruits/plant) as well as fruit weight(10kg in 2020 and 8kg in 2021) and is therefore to recommended for watermelon cultivation in Owerri, South Eastern Nigeria. [ABSTRACT FROM AUTHOR]

To explore the effect of storage temperature on Jingcai 1 watermelon, the fruits of Jingcai 1 watermelon were storaged under 5, 15 and 25 °C . The firmness, rate of weight loss, chilling injury, soluble solids, pectin, cellulose, soluble sugar, organic acid, lycopene, β-carotene and vitamin C contents were determined under different temperature treatments. The results showed that, with the storage extending, the weight loss rate of Jingcai 1 watermelon fruit increased, the fruit firmness decreased, the content of water-soluble pectin (WSP) increased, the sodium carbonate-soluble pectin (SSP) decreased, the vitamin C, lycopene and β-carotene showed decreasing trend, the variation of soluble solids fluctuated within a small rage, the cellulose decreased at first and then increased, while the content of soluble sugar and organic acid showed different changing trends at different storage temperatures. When stored at 5 °C, the vitamin C and soluble sugar of fruit could be high level, but a long-term storage would raise the chilling injury rate and cause gradual wastage of nutrients, resulting undoubtedly in loss of the edible and commercial values. When stored at 15 °C, the contents of water, organic acids and cytochromes could be better maintained, giving watermelons better quality and flavor. When stored at 25 °C, the quick loss of soluble sugar, organic acid and pectin of the fruit leaded to soft rot, depriving original flavors of watermelons and making it difficult to maintain its quality. Above results provided a theoretical basis for the commercialization of its storage, transportation and preservation. [ABSTRACT FROM AUTHOR]

Watermelon (Citrullus lanatus) holds global significance as a fruit with high economic and nutritional value. Exploring the regulatory network of watermelon male reproductive development is crucial for developing male sterile materials and facilitating cross-breeding. Despite its importance, there is a lack of research on the regulation mechanism of male reproductive development in watermelon. In this study, we identified that ClESR2, a VIIIb subclass member in the APETALA2/Ethylene Responsive Factor (AP2/ERF) superfamily, was a key factor in pollen development. RNA in situ hybridization confirmed significant ClESR2 expression in the tapetum and pollen during the later stage of anther development. The pollens of transgenic plants showed major defects in morphology and vitality at the late development stage. The RNA-seq and protein interaction assay confirmed that ClESR2 regulates pollen morphology and fertility by interacting with key genes involved in pollen development at both transcriptional and protein levels. These suggest that Enhancer of Shoot Regeneration 2 (ESR2) plays an important role in pollen maturation and vitality. This study helps understand the male reproductive development of watermelon, providing a theoretical foundation for developing male sterile materials.

Watermelon (Citrullus lanatus L.) is grown in tropical and temperate regions and an economically important crop. Characterization studies of watermelon may provide valuable information for breeding and research programs. The objectives of this study were to determined of morphological, phytochemical, genetic diversity and population structure among the watermelons. Morphological and phytochemical variations including sugar contents were determined in 96 watermelon genotypes grown in the field. The average number of fruits per plant was determined as 2.52 ± 0.06, and the average yield was determined as 6.2 ± 0.11 kg/m2. The mean total sugar was determined as 6.27 ± 0.12 %, and the lowest value was measured in genotype 234 (1.1%); the highest value was measured in genotype number 184 (8.66%). A total of 62 SSR (Simple Sequence Repeat) primers were used in the molecular characterization study. The similarity coefficients among the 96 genotypes varied between 0.23 and 0.99. This study indicates that there is a wide morphological and sugar parameters variation among watermelon genotypes but narrow molecular genetic diversity. It also provides useful information for watermelon breeding studies.

Abstract Background The KT/HAK/KUP is the largest K+ transporter family in plants, playing crucial roles in K+ absorption, transport, and defense against environmental stress. Sweet watermelon is an economically significant horticultural crop belonging to the genus Citrullus, with a high demand for K+ during its growth process. However, a comprehensive analysis of the KT/HAK/KUP gene family in watermelon has not been reported. Results 14 KT/HAK/KUP genes were identified in the genomes of each of seven Citrullus species. These KT/HAK/KUPs in watermelon were unevenly distributed across seven chromosomes. Segmental duplication is the primary driving force behind the expansion of the KT/HAK/KUP family, subjected to purifying selection during domestication (Ka/Ks

Abstract Background Sterol side-chain reductase 2 (SSR2) is a key enzyme in the synthesis of plant cholesterol pathway. Despite the importance of watermelon as a horticultural cash crop, the SSR2 gene in watermelon has not been previously studied or reported. Results In this study, 28 SSR2 genes were identified in the watermelon genome. The physicochemical properties of 28 ClaSSR proteins were predicted by bioinformatics methods, and the gene structure, conserved motif, chromosome localization, phylogenetic analysis, cis-acting elements, expression patterns, promoter activity analysis and subcellular localization of ClaSSRs were studied. The 28 ClaSSRs were unevenly distributed on 11 chromosomes, and phylogenetic analysis showed that they could be grouped into 4 groups with other related Cucurbitaceae homologous genes. Analysis of gene structure and motifs revealed similarities in exons/introns and motifs between members of the same group, further supporting phylogenetic results. The RT–qPCR results showed variations in ClaSSRs expression during watermelon fruit development. The analysis of promoter activity for ClaSSR25 showed strong activity. Subcellular localization studies confirmed that ClaSSR25 is mainly located in the cytoplasm, which aligns with the predicted outcomes. We additionally estimated the network of protein–protein interactions for ClaSSR25 and analyzed proteins that could potentially interact with ClaSSR25 in melon and Arabidopsis thaliana. Conclusions We conducted bioinformatics analysis and expression analysis of members of the watermelon SSR2 gene family in this work, and the outcomes set the stage for further investigations into the watermelon SSR2 gene. Graphical Abstract

Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera®, Gavina®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators.

This research, conducted in Gotvand, southwest Iran, evaluated the energy balance of a field system which watermelon produced in it. In the current research, energy inputs of watermelon planting were measured. To reach this goal, questionnaires were given to the farmers to record the amount of energy input to their watermelon planting field. Statistical analysis of the data revealed that nitrogen was the input with the highest consumption of energy (4175 MJ.ha-1) followed by diesel fuel. About 90% of the consumed energy of watermelon planting system was seen for energies which cannot be renewed. The results showed that the efficiency of energy consumption was positive, indicating that the amount of output energy was higher than that of input energy. With each unit of energy was consumed, 4.86 units of energy were produced, which indicates high energy efficiency. For improving the efficiency of energy usage in the watermelon planting system, nitrogen application to the system should be reduced and it can be reached by suitable rotation which diminish the nitrogen needs.

Watermelon is a widely cultivated cucurbitaceous crop with economic and dietary significance. The plant's ability to reproduce effectively relies on the harmonious growth and maturation of both its male and female flowers. At the farm level, determining the exact amount of ethylene required to regulate the development and sexual expression of individual floral buds remains uncertain, despite the known influence of exogenously applied ethylene on these processes. The goal of the research was to explore how the ethephon doses influence vegetative characteristics, sex expression, and watermelon yield. The experiment, employing a one-factorial Randomized Complete Block Design (RCBD) comprising five treatments and four replications, was conducted in a farmer's field in Buttabari, Jhapa. Using R-stat software, the data were analyzed at a 5% level of significance. Treatment consisted of Ethephon with four doses namely; 100ppm, 200ppm, 300ppm, 400ppm, and a control. Ethephon application was done twice, once at the two true-leaf stages and another at four true-leaf stages. The study revealed that plant height decreased with ethephon compared to the control, reaching a minimum of 280.1 cm at 400 ppm and a maximum of 307.1 cm in the control. Additionally, the highest branch numbers were observed with ethephon at 200 ppm. The plot treated with 200ppm ethephon was found to be more effective than alternative doses at increasing the total number of female flowers, bearing 15.25 female flowers per plant. Control (166.50 per plant) and 400 ppm (150.00 per plant) had the highest and lowest male flower counts per plant, respectively. A maximum yield of 25.12 t/ha and a minimum yield of 19.1 t/ha were determined at 200 ppm and control, respectively. Hence, farmers are found to benefit from ethephon doses of 200 ppm.

Watermelon (Citrullus lanatus) is the third largest fruit crop in the world in term of production. However, it is susceptible to several viruses. Watermelon vine decline (WVD), caused by whitefly-transmitted squash vein yellowing virus (SqVYV), is a disease that has caused over $60 million in losses in the US and continues to occur regularly in southeastern states. Understanding the molecular mechanisms underlying resistance to SqVYV is important for effective disease management. A time-course transcriptomic analysis was conducted on resistant (392291-VDR) and susceptible (Crimson Sweet) watermelon genotypes inoculated with SqVYV. Significantly higher levels of SqVYV were observed over time in the susceptible compared to the resistant genotype. The plasmodesmata callose binding protein (PDCB) gene, which is responsible for increased callose deposition in the plasmodesmata, was more highly expressed in the resistant genotype than in the susceptible genotype before and after inoculation, suggesting the inhibition of cell-to-cell movement of SqVYV. The potential role of the RNA interference (RNAi) pathway was observed in the resistant genotype based on differential expression of eukaryotic initiation factor (eIF), translin, DICER, ribosome inactivating proteins, RNA-dependent RNA polymerase (RDR), and Argonaute (AGO) genes after inoculation. The significant differential expression of hormone-related genes, including those involved in the ethylene, jasmonic acid, auxin, cytokinin, gibberellin, and salicylic acid signaling pathways, was observed, emphasizing their regulatory roles in the defense response. Genes regulating pectin metabolism, cellulose synthesis, cell growth and development, xenobiotic metabolism, and lignin biosynthesis were overexpressed in the susceptible genotype, suggesting that alterations in cell wall integrity and growth processes result in disease symptom development. These findings will be helpful for further functional studies and the development of SqVYV-resistant watermelon cultivars. [ABSTRACT FROM AUTHOR]

The experiment was conducted during the months of January to March in the year 2023 at Department of Renewable Energy Engineering, Junagadh Agricultural University, Junagadh (Gujarat). A field experiment was conducted to assess the performance of mulch and row covers in early watermelon cultivation with the primary aim on strategically removing row covers days after sowing. Randomized Block Design was employed with featuring of three treatments (mulching without row cover, mulching with row cover for 30 days and mulching with row cover for 45 days). Various yield and yield attribute parameters were recorded and analysed. The research findings indicated that the removal of row covers 30 days after sowing significantly influenced main vine length (2.72 m), number of nodes per main vine (36.40), number of fruits plant-1 (2.53), yield plant-1 (4.21 kg) and yield ha-1 (62.32 t ha-1). Removal of row covers 30 days after sowing exhibited higher net returns (₹ 4, 85, 419 ha-1) and higher benefit-cost ratio (4.52). Removal of row cover 45 days after sowing significantly reduced the watermelon yield. The results unveiled that mulching with a row cover aster 30 days of sowing is the optimal approach for increasing watermelon yield and net returns in early watermelon cultivation. [ABSTRACT FROM AUTHOR]

Watermelon is one of the most important edible plants worldwide. Owing to its special cultivation conditions, watermelon is exposed to many biological and abiotic stresses during its development. Lectin receptor-like kinases (LecRLKs) are plant-specific membrane proteins that play important roles in sensing and responding to environmental stimuli. Although the LecRLK gene family has been identified in a variety of plants, a comprehensive analysis has not yet been undertaken in watermelon. In this study, 61 putative LecRLK genes were identified in watermelon, consisting of 36 G-type, 24 L-type, and 1 C-type LecRLK genes. They were distributed in clusters on chromosomes, and members from the same subfamily were mostly clustered together. The analysis of the phylogenetic tree and conserved motif indicated that there were obvious differences among three ClaLecRLK subfamilies, and there was also rich diversity in the C-terminal within subfamilies. A collinear analysis revealed that the evolution of the ClaLecRLK gene family in different Cucurbitaceae crops was asynchronous. Furthermore, the analysis of the ClaLecRLK protein structure showed that not all proteins contained signal peptides and a single transmembrane domain. A subcellular localization assay confirmed that the number and position of transmembrane domains did not affect ClaLecRLK protein localization in cells. Transcriptome data revealed distinct expression patterns of LecRLK genes of watermelon in various tissues, and their responses to different fungi infection were also significantly different. Finally, the potential binding sites of the ClaLecRLK genes targeted by miRNA were predicted. This study enhances the understanding of the characteristics and functions of the LecRLK gene family in watermelon and opens up the possibility of exploring the roles that LecRLK genes may play in the life cycle of Cucurbitaceae plants. [ABSTRACT FROM AUTHOR]

Despite the significant contribution of stingless bees to pollination and conservation of the environment, information on their effectiveness as pollinators is insufficient. Therefore, we tested their effectiveness using watermelon, which is one of the most economically significant global food crops in terms of production volume and production value. Our study aimed at determining how bee body size, visitation rate, and bee-flower size matching ratio affect pollen deposition. We measured pollen deposition in combination with the morphometrics of 30 bees each and measurements of 30 corresponding flowers they visited. We calculated the bee-flower size matching ratio, the relationship between the bee size, and the flower measurement to gauge the effectiveness of each bee species on pollen deposition and distribution among the three watermelon stigmatic lobes. Our findings elaborate on how the different sizes of various bee parts majorly impacted the amount of pollen deposited. Besides, the number of visits, probing time, and bee behavior when handling the flower also played a role. Bees with a size matching ratio approaching 1 deposited more pollen on a single visit. However, pollen distribution highly depended on the number of visits. Among the stingless bee species, Meliponula ferruginea was the best performer. Though the honey bee species Apis mellifera was the best pollen depositor, its performance was almost similar to that of M. ferruginea. In fact, upon a single flower visit, M. ferruginea performed better than A. mellifera. Based on our findings, it can be concluded that stingless bees, particularly M. ferruginea, are effective pollinators of watermelon flowers. Furthermore, traits like probing time, multiple visits, or frequent visitation are not enough to gauge pollinator effectiveness, but there is also a need to include other traits like the size matching ratio between the bee body and flower head. [ABSTRACT FROM AUTHOR]

Background: Sterol side-chain reductase 2 (SSR2) is a key enzyme in the synthesis of plant cholesterol pathway. Despite the importance of watermelon as a horticultural cash crop, the SSR2 gene in watermelon has not been previously studied or reported. Results: In this study, 28 SSR2 genes were identified in the watermelon genome. The physicochemical properties of 28 ClaSSR proteins were predicted by bioinformatics methods, and the gene structure, conserved motif, chromosome localization, phylogenetic analysis, cis-acting elements, expression patterns, promoter activity analysis and subcellular localization of ClaSSRs were studied. The 28 ClaSSRs were unevenly distributed on 11 chromosomes, and phylogenetic analysis showed that they could be grouped into 4 groups with other related Cucurbitaceae homologous genes. Analysis of gene structure and motifs revealed similarities in exons/introns and motifs between members of the same group, further supporting phylogenetic results. The RT–qPCR results showed variations in ClaSSRs expression during watermelon fruit development. The analysis of promoter activity for ClaSSR25 showed strong activity. Subcellular localization studies confirmed that ClaSSR25 is mainly located in the cytoplasm, which aligns with the predicted outcomes. We additionally estimated the network of protein–protein interactions for ClaSSR25 and analyzed proteins that could potentially interact with ClaSSR25 in melon and Arabidopsis thaliana. Conclusions: We conducted bioinformatics analysis and expression analysis of members of the watermelon SSR2 gene family in this work, and the outcomes set the stage for further investigations into the watermelon SSR2 gene. [ABSTRACT FROM AUTHOR]

Seed size (SS) constitutes a pivotal trait in watermelon breeding. In this study, we present findings from an examination of two watermelon accessions, namely, BW85 and F211. Seeds from BW85 exhibited a significant enlargement compared to those of F211 at 13 days after pollination (DAP), with the maximal disparity in seed length and width manifesting at 17 DAP. A comprehensive study involving both metabolic and transcriptomic analyses indicated a significant enrichment of the ubiquinone and other terpenoid-quinone biosynthesis KEGG pathways. To detect the genetic region governing seed size, a BSA-seq analysis was conducted utilizing the F2 (BW85 × F211) population, which resulted in the identification of two adjacent QTLs, namely, SS6.1 and SS6.2, located on chromosomes 6. SS6.1 spanned from Chr06:4847169 to Chr06:5163486, encompassing 33 genes, while SS6.2 ranged from Chr06:5379337 to Chr06:5419136, which included only one gene. Among these genes, 11 exhibited a significant differential expression between BW85 and F211 according to transcriptomic analysis. Notably, three genes (Cla97C06G113960, Cla97C06G114180, and Cla97C06G114000) presented a differential expression at both 13 and 17 DAP. Through annotation, Cla97C06G113960 was identified as a ubiquitinconjugating enzyme E2, playing a role in the ubiquitin pathway that mediates seed size control. Taken together, our results provide a novel candidate gene influencing the seed size in watermelon, shedding light on the mechanism underlying seed development. [ABSTRACT FROM AUTHOR]

In order to clarify the optimal spore production and inoculation methods for watermelon stem blight (Stagonosporosis cucurbitaceae), and to lay a solid foundation for the screening and identification of watermelon stem blight resistant germplasm resources, this article focuses on the spore production and inoculation methods of watermelon stem blight. Two common spore production methods were compared from the aspects of spore production time, spore yield, and spore morphology of stem blight. It was found that the UV induced spore production method had shorter spore production time, more stable spore yield, normal spore morphology, and lower cost compared to the cucumber induced spore production method. Currently, it was the best spore production method for watermelon stem blight. Watermelon resistant and susceptible materials were also inoculated with the methods of inoculum cake in vitro, spot inoculation with live spore suspension, and spray inoculation with live spore suspension, respectively. The three inoculation methods were compared in terms of operation difficulty and accuracy, and it was found that each of the three inoculation methods had advantages and disadvantages. The difference of resistance and susceptibility of watermelon resistant and susceptible materials was obvious after inoculating in vitro with cake inoculation and in vivo spore suspension spot inoculation, while the susceptible materials showed moderate resistance after inoculating in vivo spore suspension spray inoculation. Through comparison, it was found that the in vitro bacterial cake inoculation method and the live spore suspension point grafting method were more reliable, but the disease grading standards of the in vitro bacterial cake inoculation method were not precise enough, and the small differences in resistance between materials were difficult to reflect; the live spore suspension point grafting method had high accuracy, but the operation was complex, time-consuming, and labor-intensive; in vivo spore suspension spray inoculation method was simple in operation, but it was difficult to accurately control the amount of inoculum, and the accuracy was general. Therefore, it was suggested that the live spore suspension spray inoculation method could be used for preliminary screening when identifying the resistance of large quantities of materials to Fusarium wilt, and the live spore suspension spot connection method could be used when identifying the resistance of a small number of materials to Fusarium wilt, and the isolated cake inoculation method could be used as an auxiliary method to further verify the inoculation results. [ABSTRACT FROM AUTHOR]

The sugar content in watermelon significantly influences its flavor. To understand the sugar accumulation pattern in small-fruited watermelon and identify candidate genes involved in sugar synthesis and conversion, we measured the sugar content (sucrose, fructose, and glucose) at five developmental stages: 10d, 16d, 22d, 28d, and 34d post-pollination. Two watermelon varieties with the largest sugar content difference at 28d post-pollination (high-sugar G38-28 and low-sugar 482276-28) were selected for transcriptome sequencing. Differentially expressed genes (DEGs) were validated using RT-qPCR. Additionally, the sugar contents of three commercial varieties ('Su Meng NO.5', 'Su Meng NO.6', 'Su Meng NO.7') and their parents were compared at five stages. Results showed glucose and fructose levels peaked between 22d and 28d, followed by a decrease, while sucrose content continuously increased. F1 hybrids exhibited glucose and sucrose trends similar to their paternal parent and fructose trends similar to their maternal parent. Transcriptome sequencing identified 9337 DEGs (5072 upregulated and 4265 downregulated). Gene Ontology analysis highlighted overrepresentation in categories such as pectinase and oxidoreductase activity. KEGG analysis identified 12 DEGs involved in sugar synthesis and conversion pathways, including phenylpropanoid biosynthesis and pentose and glucuronate interconversions. RT-qPCR validation corroborated the transcriptome data. These findings explain the distinct sugar accumulation patterns in G38-28 and 482276-28 at the transcriptional level, offering insights for genetic breeding and regulation of key sugar-related genes in watermelon. [ABSTRACT FROM AUTHOR]

Grafting alters the genetic and anatomical features of plants. Although grafting has been widely applied in plant propagation, the underlying processes that govern the effects of the procedure are not fully understood. Samples were collected to study the long-term influence of grafting on the leaf-shoot morphology, leaf-shoot anatomy, and genetic signature of the grafted plants. Citrulus lanatus (Thunb.) Matsum. & Nakai (cv. Lady) was used as the scion, and Lagenaria siceraria (Molina) Standl (cv. Argentario) as a rootstock. In grafted plants, leaf blades and petioles were 20.92% and 12.82% longer, respectively, while the midrib collenchyma was 35.68% thicker, and the diameter of the vessel member was 11.17% larger than in ungrafted plants. In the stem, grafting affected the arrangement and number of vascular bundles (from 1 to 2 rings). The thickness of the epidermis decreased by 69.79%, and the size of the external fascicular phloem decreased by 23.56%. The diameter of the vessel member of the grafted plants increased by 28.94%. Eight out of ten evaluated primers met the requirements (stability in both watermelons and bottle gourd, tissue-specific). In the genetic tests, we examined whether this change in the gene expression pattern is due to the grafting and, if so, to what extent. Seven out of eight tested Small Auxin Up-Regulated RNA (SAUR) genes were expressed in the ungrafted and grafted C. lanatus lines in four cases; the expression increased by more than 10% after grafting. The morpho-anatomical changes and genetic variation reported in this study for grafted lines of C. lanatus contribute to the understanding of the underlying mechanisms of plant growth observations resulting from grafting. [ABSTRACT FROM AUTHOR]

The watermelon (Citrullus lanatus L.) holds substantial economic value as a globally cultivated horticultural crop. However, the genetic architecture of watermelon fruit weight (FW) remains poorly understood. In this study, we used sh14-11 with small fruit and N14 with big fruit to construct 100 recombinant inbred lines (RILs). Based on whole-genome resequencing (WGR), 218,127 single nucleotide polymorphisms (SNPs) were detected to construct a high-quality genetic map. After quantitative trait loci (QTL) mapping, a candidate interval of 31–38 Mb on chromosome 2 was identified for FW. Simultaneously, the bulked segregant analysis (BSA) in the F2 population corroborated the identification of the same interval, encompassing the homologous gene linked to the known FW-related gene fas. Additionally, RNA-seq was carried out across 11 tissues from sh14-11 and N14, revealing expression profiles that identified 1695 new genes and corrected the annotation of 2941 genes. Subsequent differential expression analysis unveiled 8969 differentially expressed genes (DEGs), with 354 of these genes exhibiting significant differences across four key developmental stages. The integration of QTL mapping and differential expression analysis facilitated the identification of 14 FW-related genes, including annotated TGA and NAC transcription factors implicated in fruit development. This combined approach offers valuable insights into the genetic basis of FW, providing crucial resources for enhancing watermelon cultivation. [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 Glasnik Zastite Bilja is the property of Zadruzna Stampa D.D. 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: The gummy stem blight caused by the fungal pathogen Didymella bryoniae (Auersw.) is a common and serious disease of watermelon plants in Vietnam. Bacillus species have been used to control plant diseases as biological control agents. The objectives of this studies were to determine the fungal inhibition of D. bryoniae and disease suppression of gummy stem blight under greenhouse by Bacillus sp. strains. Methods: The study was carried out at University of Agriculture and Forestry, Hue University during 2022-2023. Six potential Bacillus strains namely S1A1, S1F3, S13E2, S13E3, S18F11 and S20D12 isolated from stem-base of groundnut in central Vietnam were tested its fungal inhibition of D. bryoniae and disease suppression of gummy stem blight. Result: All tested strains of Bacillus sp. showed inhibition of the hyphal growth of D. bryoniae strain DB-01 in potato dextrose broth. Among the strains, Bacillus sp. S20F12 had highest inhibition of the growth of mycelia of D. bryoniae strain DB-01 with an antagonistic efficiency of 65.7% at 10 days after fungal inoculation. By 21 days after fungal inoculation, disease incidences were low in the plants treated with Bacillus sp. S20D12 and S1F3 by 46.6 and 50.0% and disease severity by 15,3% and 20.6%, respectively. As results, watermelon plants were prevented from damage of gummy stem blight caused by D. bryoniae strain BD-01 by Bacillus sp. S20D12 and S1F13. The results would contribute to the knowledge of antagonistic activities of the Bacillus to optimize the biological control against D. bryoniae. [ABSTRACT FROM AUTHOR]

This study utilized a plant-wearable sap flow sensor developed by a multidisciplinary team at Zhejiang University to monitor water distribution patterns in watermelon fruit stalks throughout their developmental stages. The dynamic rules of sap flow at different stages of fruit development were discovered: (1) In the first stage, sap flow into the fruit gradually halts after sunrise due to increased leaf transpiration, followed by a rapid increase post-noon until the next morning, correlating with fruit expansion. (2) In the second stage, the time of inflow sap from noon to night is significantly shortened, while the outflow sap from fruit is observed with the enhancement of leaf transpiration after sunrise, which is consistent with the slow fruit growth at this stage. (3) In the third stage, the sap flow maintains the diurnal pattern. However, the sap flow that inputs the fruit at night is basically equal to the sap flow that outputs the fruit during the day; the fruit phenotype does not change anymore. In addition, a strong correlation between the daily mass growth in fruit and the daily sap flow amount in fruit stalk was identified, validating the sensor's utility for fruit growth monitoring and yield prediction. [ABSTRACT FROM AUTHOR]

Plant architecture includes traits such as plant height, stem diameter, and branching pattern, which have significant impacts on yield and fruit quality. Polyploidization can bring changes in plant architectural traits in different crops along with other agronomic and biochemical attributes; however, the specific physiological and biochemical mechanisms are still unclear. In this study, we utilized five watermelon lines: '91E7', 'Zhengzhou No. 3', 'Fanzu No. 1', 'Shenlong', and 'Houlv', along with their corresponding autopolyploid derivatives (diploid, autotriploid, and autotetraploid) to compare plant architecture differences in different polyploidy watermelon plants. The results showed that the growth habits of diploid, triploid, and tetraploid watermelon plants were noticeably different. Triploid and tetraploid watermelon plants had greater stem diameters and larger leaf sizes. The leaf angle was also larger in polyploid watermelons than in their diploid ancestor lines. Although vine length was significantly higher in diploid watermelon, there was no significant difference in node number, indicating that the short vine length was due to the short internodal length. The major differences between diploid and polyploid watermelon plants were found in the branching pattern, as diploid watermelon lines have more branching compared to their polyploid sister lines. Furthermore, we examined the phytohormone content of diploid, triploid, and tetraploid 'Fanzu No. 1'. The reasons for the selection of this material are its robust growth and profuse branching habit, which cause visible differences among the ploidy levels. Hormone analysis showed distinct variations in abscisic acid in the nodal and stem regions, gibberellin in the auxiliary bud regions, and brassinosteroids in the apical meristematic regions. The correlation coefficient also strongly correlated these hormones with architecture-related traits. Our findings indicated that gibberellin, ABA, and brassinosteroids might be associated with variations in plant architectural traits like branching, vine length, internodal length, stem thickness, and leaf angle among different ploidy levels of watermelon. The exogenous application of GA3 showed a positive effect on branching, whereas ABA showed a negative effect on branching. The application of brassinosteroid at the apical meristem demonstrated its effect on leaf angle, leaf size, and internodal length. The results of this study can provide a theoretical reference and valuable insights into the link between plant architecture and ploidy levels. [ABSTRACT FROM AUTHOR]

Industrial development and population growth are two key factors that have led to increased energy consumption. Conventional energy sources are fast becoming insufficient in matching the increased demands. Over the last two decades, a great interest in exploring alternative energy sources has been developed. Amongst the highly sought for alternatives to fossil fuel, biofuel has gained high recognition. In this research, bioethanol produced from cofermentation of watermelon and pineapple waste using Saccharomyces cerevisiae was successfully studied and compared to standard values. Performance evaluation of the spark ignition (S.I) single cylinder, four stroke and air-cooled engine running on gasoline and bioethanol blends was analysed. The engine brake power, torque, exhaust gas temperature performance with E14 (blending 14% bioethanol with 86% gasoline) was found to be better than pure petrol at various load ranging between 500g to 3000g. The brake specific fuel consumption was however better with gasoline than the blends at various loads. The overall performance results showed that a blend containing 14% bioethanol, and 86% gasoline can be successfully used as petrol substitute without any modification in the available engine design. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) 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.)

Turbidity is of great concern in drinking water treatment. Coagulation-flocculation (CF) process is widely applied for removing turbidity, which depends on coagulant type. Alumchemical coagulant is commonly used due to its superiority in removing it. However, alum has been associated with several adverse impacts on human health and the environment. Natural coagulants (eco-friendly materials) cannot be a feasible alternative to alum due to their limited coagulating performance in turbidity removal. In our previous research, novel approach to reduce alum impact by partially replacing it with natural coagulant was developed based on two consecutive treatments of CF process. Its concept was that a natural coagulant was used in primary treatment to significantly reduce turbidity and alum was used in secondary treatment at a minimum dose. This approach was successfully applied for treating bentonite turbid water. To verify if its concept is feasible for treating kaolin turbid water, this research was carried out. Experimental results showed that the novel approach achieved superior performance in reducing turbidity of treated water from 950 NTU to less than 5 NTU (i.e., satisfying the WHO drinking water standards) and decreasing alum dose required by 33 and 50% using palm bark and watermelon coagulants, respectively when compared with alum control treatment (i.e., replacing partially alum). The novel approach findings in current research are consistent with our previous research. Concluding its concept is validated with two types of bentonite and kaolin turbid waters. Further work needs to verify if its concept is feasible for treating river surface water. [ABSTRACT FROM AUTHOR]

Watermelon is commonly affected by Fusarium wilt in a monoculture cropping system. Wheat intercropping alleviates the affection of Fusarium wilt of watermelon. The objective of this study was to determine the effects of wheat and watermelon intercropping on watermelon growth and Fusarium wilt. Our results showed that wheat and watermelon intercropping promoted growth, increased chlorophyll content, and photosynthesis of watermelon. Meanwhile, wheat and watermelon intercropping inhibited watermelon Fusarium wilt occurrence, decreased spore numbers, increased root vigor, increased antioxidant enzyme activities, and decreased malondialdehyde (MDA) content in watermelon roots. Additionally, wheat and watermelon intercropping enhanced the bacterial colonies and total microbes growth in soil, decreased fungi and Fusarium oxysporum f. sp. niveum (FON) colonies, and increased soil enzyme activities in watermelon rhizosphere soil. Our results indicated that wheat and watermelon intercropping enhanced watermelon growth and decreased the incidence of Fusarium wilt in watermelon. These effects could be due to intercropping inducing physiological changes, regulating soil enzyme activities, and/or modulating soil microbial communities. [ABSTRACT FROM AUTHOR]

This study aims to estimate the consumptive water use (CWU) for watermelon production in Auchi, Edo State, Nigeria. The research was conducted over a period of eight months (March–October) and used data collected from the watermelon field at the Demonstration and Research Farm of Auchi Polytechnic, Auchi. The result of the experiment revealed the estimation of CWU and watermelon water requirements (CWR) of 175.9 mm and 195 mm for the 62-day (August to October) vegetation stage of watermelon, with a CROPWAT projected harvest on November 20, 2022. The finding also revealed that the mean annual consumptive water use for watermelon production was 520.7 mm. The mean seasonal water use for watermelon production was higher in the dry season (March to June, 488.7mm) than in the wet season (July to October, 390.6mm). However, based on this harvest date, the model predicted irrigation requirements of 23.1 mm and 59.4 mm in October and November. Additionally, this study offers proof that management strategies for water use efficiency and irrigation scheduling can dramatically lower water losses and boost efficiency. The findings of this study can be applied to the Auchi region’s water management decision-making procedures as well as to help watermelon farmers reduce their water consumption levels while maintaining output.

Nutrient management recommendations for watermelon are described according to the standard UF/IFAS recommendation format of 1) a calibrated soil test result; 2) target soil pH; 3) the "4Rs" of fertilizer management: rate, timing, placement, and source; and 4) water management factors.

Grafting of vegetable crops is widely used in industrial vegetable growing in Asia and Western Europe. However, the influence of the genetic relationship of the scion and rootstock, the activity of peroxidase and the content of ascorbic acid in the components of the graft during inosculation period on graft survival has been poorly studied. The objects of the research are nine species of the pumpkin family (Cucurbitaceae). The polymorphism of 11 taxa was studied based on ISSR-PCR of genomic DNA. The record of survival rate of scion-rootstock combinations was conducted on the 10-th day. The activity of peroxidase was determined by the spectrophotometric method, the content of ascorbic acid was determined by Murri. Significant differences in survival rate were noted when grafting momordica into pumpkin rootstock variants: large-fruited (94.6 %) and nutmeg (67.1 %). In experiments with watermelon, melon and trichosanthes, the influence of the type of rootstock on the viability of the graft was not revealed. According to the ISSR spectra, the taxa were divided into two clusters; interspecific groupings of each clade were supported by average bootstrap values (from 26 to 100 %). A medium effect (r = 0.36) of the degree of genetic similarity of the scion with the rootstock on the survival rate of watermelon and a weak effect on the survival rate of melon, momordica and trichosanthes were revealed. The activity of peroxidase and the content of ascorbic acid in the grafting components in different scionrootstock combinations had a weak and moderate effect on plant survival, respectively. The survival rate of trichosanthes on various types of rootstocks strongly depended on the content of ascorbic acid (r = 0.7). Genetic relatedness, peroxidase activity, and ascorbic acid content had a weak or moderate effect on the survival rate of plants in scion-rootstock combinations.