Melon Fruit Quality Research Articles

Melon Fruit Detection and Quality Assessment Using Generative AI-Based Image Data Augmentation

Melon Fruit Detection and Quality Assessment Using Generative AI-Based Image Data Augmentation

Effect of Vermicompost Application on the Soil Microbial Community Structure and Fruit Quality in Melon (Cucumis melo)

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

Transcription Factor CmWRKY13 Regulates Cucurbitacin B Biosynthesis Leading to Bitterness in Oriental Melon Fruit (Cucumis melo var. Makuwa Makino).

Bitterness, caused by cucurbitacin B (CuB), is one of the important traits that affects melon fruit quality and consumer acceptance. Therefore, the detailed mechanism behind the regulation of CuB biosynthesis on melon fruit needs to be further explored. This study investigated CuB content and transcriptomes of "YMR" melon fruit treated by 5 and 20 mg L-1 CPPU. The content of CuB reaches its peak in 5 days and then decreases. WGCNA identified the WRKY transcription factor (TF), CmWRKY13, coexpressed with CuB biosynthetic genes (Cm180, Cm170, Cm160, and CmACT). Yeast one-hybrid, dual-luciferase, and transient gene expression assays were conducted and suggested that the nucleus-localized CmWRKY13 transactivated the promoters of CuB biosynthetic genes and participated in the regulation of CuB biosynthesis. Furthermore, CmWRKY13 could interact with CmBt, the fruit bitterness-specific TF, which synergistically activated CuB biosynthetic gene expression. These findings provide a novel mechanistic insight for CuB biosynthesis and regulation in melon cultivation.

Do moderate salinity and harvest stages interfere with gas exchange and quality of yellow melon fruits?

Do moderate salinity and harvest stages interfere with gas exchange and quality of yellow melon fruits?

Effects of molybdenum on growth and fruit quality of small fruit melon (Cucumis melo L.) cultivated under high-temperature stress

Effects of molybdenum on growth and fruit quality of small fruit melon (Cucumis melo L.) cultivated under high-temperature stress

Assessment of major insect pests of golden melon (Cucumis melo L.) and control with commercial Beauvaria bassiana in Abeokuta Southwestern, Nigeria

Pest infestation is a major challenge in production of golden melon, this study evaluated the performance of Beauvaria bassiana, a non-residual bio-pesticide, for effectiveness against insect pests of golden melon. The field experiment was carried out in 2022 to establish the effect of B. bassiana sprayed at different growth stages on the abundance of insect pests, damage, agronomic characteristics and fruit quality of golden melon. The results showed Aulacophora spp., Aphis gossypii, Epilachna chrysomelina, Bemisia tabaci Coridius viduatus and Zonocerus variegatus as the insect pests attacking golden melon in the study area. However, the population densities of Aulacophora spp. and E. chrysomelina were significantly lower in golden melon sprayed with B. bassiana at all compared to other spray treatments and the control. Percentage leaf damage and yield loss (20.81% and 327.70 g) in golden melon sprayed with B. bassiana at all stages were similar to lambda-cyhalothrin-sprayed plot (13.68 % and 318. 70 g). Also, highest percent leaf damage and yield losses (81.54 % and 1395.70 %) were obtained in the control plots relative to other spray treatments. Number of leaves and percentage increase in vine length were significantly higher in the golden melon sprayed with B. bassiana at all stages. There was 215.80 % increase in yield of golden melon sprayed with B. bassiana at all stages over the control in the study. Also, the nutritional composition of the fruits from the untreated plots was similar to that of the treated plots

Melon cultivation under agrotextile increases production and reduces phytosanitary products

Abiotic and biotic factors influence the productivity and quality of melon fruit; therefore, the protection of plants using agrotextile mesh is a solution that can be agronomically viable, as it reduces the use phytosanitary pesticides and allows for greater productivity and, consequently, quality. The objective this study was to evaluate the influence of coverage time with an agrotextile (0, 21, 26 and 31 days after transplanting (DAT)) in melon hybrids ‘Gold Mine’, ‘Soleares’, ‘Lual’ and ‘Natal’ on productivity and fruit quality attributes. The plants that were protected with agrotextile mesh for 21 and 26 DAT had higher productivity (53.5 and 52.1 t ha−1). Among the hybrids, all excellent plots produced above 42.4 1 t ha−1. Of the observed hybrid quality parameters, 'Natal' protected for 21 DAT showed a better total phenol content and a higher maturation index, and 'Soleares' protected for 21 DAT showed a higher DPPH antioxidant activity and flavonoid content.

Desenvolvimento e qualidade de frutos de melão amarelo sob estresse salino

ABSTRACT The need for studies that allow the use of brackish water in irrigated agriculture and the socioeconomic importance of melon cultivation in Brazil, especially for the Northeast region, which concentrates most of the national production and faces problems with the availability of good quality water for irrigation, motivated the present study. In this context, the objective of present study was to evaluate the growth, production and fruit quality of the ‘Goldex’ (yellow-type hybrid F1) melon under salt stress conditions. The experiment was performed in a completely randomized design, with two salinity levels of irrigation water (0.8 and 4.0 dS m-1) and eight evaluation times (52, 54, 56, 58, 60, 62, 64, and 66 days after transplanting). Variables of plant growth and development, production and quality of melon fruits were evaluated throughout the cycle. Plants had delayed growth characteristics and less development with the increase in irrigation water salinity, showing reductions of more than 20% in shoot dry weight, leaf area, number of branches and length of secondary branches and 16.7% in length of the main branch. In addition, salinity caused a delay in fruit development and a 16% reduction in final fruit weight, without significantly modifying carbohydrate and total soluble solids contents. Along the development, there was an increase in the total soluble solids content of the fruits, especially due to the increment of sucrose at the final stages of development.

Rice husk ash based growing media impact on cucumber and melon growth and quality

Rice husk, an agricultural waste from the rice industry, can cause serious environmental pollution if not properly managed. However, rice husk ash (RHA) has been found to have many positive properties, making it a potential replacement for non-renewable peat in soilless planting. Thus, this study investigated the impact of a RHA composite substrate on the growth, photosynthetic parameters, and fruit quality of cucumber (Yuyi longxiang variety) and melon (Yutian yangjiaomi variety). The RHA, peat, vermiculite, and perlite were blended in varying proportions, with the conventional seedling substrate (peat:vermiculite:perlite = 1:1:1 volume ratio) serving as the control (CK). All plants were cultivated in barrels filled with 10L of the mixed substrates. The results from this study found that RHA 40 (RHA:peat:vermiculite:perlite = 4:4:1:1 volume ratio) significantly enhanced substrate ventilation and positively influenced the stem diameter, root activity, seedling index, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) of cucumber and melon plants. Additionally, plant planted using RHA 40, the individual fruit weight of cucumber and melon found to increase by 34.62% and 21.67%, respectively, as compared to the control. Aside from that, both cucumber and melon fruits had significantly higher sucrose, total soluble sugar, vitamin C, and soluble protein levels. This subsequently improved the activity of sucrose synthase and sucrose phosphate synthase in both cucumber and melon. In conclusion, the RHA 40 found to best promote cucumber and melon plant growth, increase plant leaf photosynthesis, and improve cucumber and melon fruit quality, making it a suitable substrate formula for cucumber and melon cultivation in place of peat.

Post-harvest quality of melon accessions subjected to salinity.

The objective was to evaluate the behavior of melon genotypes (Cucumis melo L.) in the physical, chemical and biochemical quality of melon fruits as a function of electrical conductivity irrigation water levels (ECw). The experimental design adopted was randomized blocks in a 5 x 3 factorial scheme with five replications. The first factor was represented by five salinity levels (0.5, 1.5, 3.0, 4.5, and 6.0 dS m-1) and the second factor by accessions A35, and A24, and the hybrid Sancho. The physical, chemical and biochemical variables showed a reduction in production, with smaller fruits, with less weight, smaller cavity, with increased pulp thickness for Sancho. Vitamin C and yellow flavonoids increased indicating antioxidant power against ROS. The genotypes showed similar post-harvest behavior, however, the hybrid Sancho stood out over the others, possibly because it is an improved material. Accession A24 presented physiological and biochemical responses that classify it as intolerant.

The interaction between CmPIF8 and CmACO1 under postharvest red light treatment might affect fruit ripening and sucrose accumulation in oriental melon fruit

Light and plant hormones are involved in regulating the growth, development and fruit quality formation. However, it remains unclear whether light regulates the fruit quality of oriental melon by affecting hormones. Sucrose is mainly accumulated in mature oriental melon fruit, and the accumulation of sucrose is closely related to ethylene. Here, the climacteric melon fruit ‘HS’ were treated with red and blue light at ethylene release initial stage (30 d after anthesis, DAA), and the results showed that the red light treatment enhanced the production of ethylene and the activity of 1-aminocyclopropane-1-carboxylate oxidase (ACO), as well as CmACO1 expression in melon fruit at postharvest stage. Red light also up-regulated the sucrose accumulation and the activity of sucrose phosphate synthetase (SPS) and CmSPS1 expression in postharvest melon fruit. Moreover, we found that PHYTOCHROME INTERACTING FACTOR 8 (PIF8), as a negative regulator of ethylene biosynthesis by directly binding to CmACO1 promoter. In summary, red light treatment at postharvest stage suppressed the expression of CmPIF8, and released the inhibitory effect of CmPIF8 on CmACO1, thereby promoting the ethylene production and fruit ripening, which indirectly increased the sucrose content in melon fruit.

Prototype of Melon Fruit Quality Sorter Based on Skin Texture Using Local Binary Pattern Histogram

Cucumis Melo L is one of the popular fruits in Indonesia. The numerous benefits and various contents of melon make it highly valuable for human health. Determining the quality of melon is crucial, considering its numerous benefits and contents. The quality of melon is determined by the presence of net-like patterns on the surface of the fruit's skin when it is ripe for harvest. Currently, conventional methods that rely on direct visual observation are still commonly used to sort the quality of melons. Therefore, a prototype system was developed to sort the quality of melons based on the texture of their skin. The purpose of this system is to reduce errors caused by eye fatigue and variations in accuracy during the sorting process. In this research, the feature extraction method of the local binary pattern (LBP) was employed, along with the K-Nearest Neighbor (KNN) method for classification. The classification was divided into two grades: Grade A and Grade B melons. The testing phase involved 200 data samples, with each grade consisting of 100 data samples. The results of the testing phase showed a success rate of 96% for the system. Based on the percentage, it can be concluded that the system has successfully performed well in sorting the quality of melons based on the texture of their skin.

Red light activates H2O2 signal involved in powdery mildew resistance in oriental melon seedlings

Melon is one of the most important horticultural crops in Asia. Powdery mildew (PM) is frequently occurred in facility cultivation, which seriously affects its yield and fruit quality of melon. Light signal is the basis of plant growth and development, and appropriate red light (RL) plays an important role in regulating the resistance of plant pathogens. Reactive oxygen species (ROS) also have been shown to be participated in plant defence against pathogen infection. However, whether light is involved in PM resistance through ROS remains unclear. Here, we found that RL+PM treatment significantly enhanced the resistance of PM in melon seedlings, improved NADPH oxidase activity, upregulated respiratory burst oxidase homologue 1 (RBOHD) expression, and increased hydrogen peroxide (H2O2) level. Compared with the PM treatment alone, diphenylene iodonium (DPI)+PM treatment significantly enhanced the sensitivity to PM in melon seedlings and weakened the effect of RL-induced PM resistance. Further studies showed that silencing CmRBOHD significantly inhibited the RL-induced PM resistance by inhibiting H2O2 synthesis. In addition, CmWRKY50 could activate CmRBOHD expression by binding to the promoter of CmRBOHD. Taken together, the results suggest that RL can increase endogenous H2O2 levels and induce the initiation of defence through activation of CmWRKY50, and therefore, when plants are subjected to pathogen stress, higher H2O2 levels in the plants are beneficial for organizing the invasion of pathogens and enhancing powdery mildew resistance.

Hybridization Between the Canary Melon and a Vietnamese Non-sweet Melon Cultivar Aiming to Improve the Growth Performance and Fruit Quality in Melon (Cucumis melo L.).

Canary melon has been widely consumed as a dessert fruit due to its fragrance, sweetness, and flavorful taste. However, the cultivation of this cultivar has been challenged in Vietnam because of its weak growth performance and high susceptibility to local pathogens. In this study, we aim to generate the hybrid melon lines between the Canary melon and a local non-sweet melon that are expected to produce good quality fruits as well as to show better growth performance in the local cultivation conditions. Two crossing pairs including (1) MS hybrid (♂ non-sweet melon × ♀ Canary melon) and (2) MN-S hybrid (♂ Canary melon × ♀ non-sweet melon) were carried out and two hybrid lines were subsequently obtained. Next, different phenotypic and physiological parameters such as stem length, stem diameter, 10th leaf diameter, fruit size, fruit weight, and fruit sweetness (pH, °Brix, and soluble sugar contents) were examined and compared between the parental lines (Canary melon and non-sweet melon) and the hybrid lines (MS and MN-S). The results showed that the stem length and fruit size and weight of MS and MN-S hybrids were higher than those of Canary melon. Basically, the content of sugars (sucrose, glucose, and fructose) is a primary and important factor in determining the sweetness of the melon. The pH, °Brix, sucrose and glucose contents of MS hybrid and Canary melon fruits were higher in comparison to MN-S and non-sweet melon fruits. Accordingly, the transcript levels of different sugar metabolism-related genes including SUCROSE SYNTHASE 1 (SUS1), SUS2, UDPGLC EPIMERASE 3 (UGE3), and SUCROSE-P SYNTHASE 2 (SPS2) were examined in all studied lines. In the fruits, the expression levels of these genes were found to be highest in the Canary melon, average in the MS hybrid, and relatively low in the MN-S hybrid and non-sweet melons. Taken together, the heterosis in terms of plant and fruit size was obviously observed in this crossing approach. The relatively high fruit sweetness in the MS hybrid (the mother is Canary melon) also implies that the choice of the mother for crossing is very important since it can determine the fruit quality of the offspring.

Identification of candidate genes that regulate the trade-off between seedling cold tolerance and fruit quality in melon (Cucumis melo L.).

Trade-offs between survival and growth are widely observed in plants. Melon is an annual, trailing herb that produces economically valuable fruits that are traditionally cultivated in early spring in China. Melon seedlings are sensitive to low temperatures, and thus usually suffer from cold stress during the early growth period. However, little is known about the mechanism behind the trade-offs between seedling cold tolerance and fruit quality in melon. In this study, a total of 31 primary metabolites were detected from the mature fruits of eight melon lines that differ with respect to seedling cold tolerance; these included 12 amino acids, 10 organic acids, and 9 soluble sugars. Our results showed that concentrations of most of the primary metabolites in the cold-resistant melons were generally lower than in the cold-sensitive melons; the greatest difference in metabolite levels was observed between the cold-resistant line H581 and the moderately cold-resistant line HH09. The metabolite and transcriptome data for these two lines were then subjected to weighted correlation network analysis, resulting in the identification of five key candidate genes underlying the balancing between seedling cold tolerance and fruit quality. Among these genes, CmEAF7 might play multiple roles in regulating chloroplast development, photosynthesis, and the ABA pathway. Furthermore, multi-method functional analysis showed that CmEAF7 can certainly improve both seedling cold tolerance and fruit quality in melon. Our study identified an agriculturally important gene, CmEAF7, and provides a new insight into breeding methods to develop melon cultivars with seedling cold tolerance and high fruit quality.

Foliar application of fish protein peptide improved the quality of deep-netted melon

To improve the fruit quality of deep-netted melon, fish protein peptide (FPP) with a total protein content greater than 90% at a concentration of 1 g·L−1 was sprayed on leaves after pollination, distilled water was sprayed on the control plants (CK). Field indices such as single melon fresh mass, commercial fruit rate, yield and fruit nutrient contents were evaluated. Soluble sugar, starch, organic acid and the activities of enzymes related to sugar metabolism in the inner, middle and outer layers of melon flesh were also determined. The results showed that the commercial fruit rate and yield per hectare increased by 8.96% and 5.98%, respectively. Nutrient contents increased, including the total amounts of 16 amino acids were 0.34 g/100 g higher than those of CK, and the mineral element contents increased by 15.79%, among which the contents of potassium, phosphorus, zinc, calcium, magnesium and molybdenum were significantly different from those of CK (p < 0.05). FPP treatment significantly increased the soluble sugar content in the outer layer of the mesocarp of deep-netted melon and the ascorbic acid contents in the inner and middle layers of the mesocarp of deep-netted melon. FPP increased sucrose accumulations in fruit by decreasing the activity of neutral invertase (NI), increasing the activity of sucrose phosphate synthase (SPS) and the synthesis direction of sucrose synthase (SS), and by increasing the glucose and fructose contents by enhancing the activity of acid invertase (AI). These findings suggest that exogenous FPP improves the commercial fruit rate, yield, and quality of deep-netted melon.

Melon yellow-green plant (Cmygp) encodes a Golden2-like transcription factor regulating chlorophyll synthesis and chloroplast development.

A SNP mutation in CmYGP gene encoding Golden2-like transcription factor is responsible for melon yellow-green plant trait. Chlorophylls are essential and beneficial substances for both plant and human health. Identifying the regulatory network of chlorophyll is necessary to improve the nutritional quality of fruits. At least six etiolation genes have been identified in different melon varieties, but none of them have been cloned, and the molecular mechanisms underlying chlorophyll synthesis and chloroplast development in melon remain unclear. Here, the NSL73046, a yellow-green plant (Cmygp) mutant, enabled the map-based cloning of the first etiolation gene in melon. CmYGP encodes a Golden2-like transcription factor. Spatiotemporal expression analyses confirmed the high CmYGP expression in all green tissues, particularly in young leaves and fruit peels. Virus-induced gene silencing and the development of near-isogenic line by marker-assisted selection further confirmed that downregulation of CmYGP can reduce chloroplast number and chlorophyll content, thereby resulting in yellow-green leaves and fruits in melon, and overexpression of CmYGP in tomatoes also led to dark-green leaves and fruits. RNA-seq analysis revealed that CmYGP greatly affected the expression of key genes associated with chloroplast development. Taken together, these findings demonstrated that CmYGP regulate chlorophyll synthesis and chloroplast development thus affect fruit development in melon. This study also offers a new strategy to enhance fruit quality in melon.

Influence of Composition of Soilless Substrates Monitored with Iot Sensor Nodes on the Growth, Nutrient and Fruit Quality of Rockmelons (Cucumis melo Var. Cantalupensis)

Background: Coconut coir dust (CD) is commonly used for growing selected fruit and vegetables. It is a soilless medium with excellent drainage and high-water holding capacity; free from infestations of weeds and pathogens. However, plant growth is adversely affected due to its high salinity, potassium and low pH. Methods: A greenhouse experiment was conducted to investigate the influence of different soilless media on rock melon’s growth, nutrient and fruit quality. Five soilless media were prepared including CD as control. A customised portable IoT system was deployed to monitor and collect relevant real-time agronomic data. Result: Plant height, yield, leaf area, total fresh fruit weight and soluble solids content (sweetness) of rock melon were significantly affected by the growing medium. Among the five media used, the growth and quality characteristics were highest in M2 followed by M3. It was found that a combination of burnt rice husk (BRH) and perlite with CD remarkably improved the growth of fruit quality of rock melon.

Rootstock identity in melon-pumpkin graft combinations determines fruit metabolite profile.

Grafting has the potential to improve melon fruit yield and quality, but it is currently held that a lack of compatibility between the rootstock and scion compromises such an effect. To throw light on this subject, we studied melon-pumpkin graft combinations with different levels of compatibility to assess to the effect of the rootstock identity on melon fruit yield and quality, including total fruit ortho-diphenols, total flavonoids, and primary fruit metabolites. Melon cv. 'Kiran' (Ki) was grafted onto three pumpkin rootstocks, 'TZ-148' (TZ), 'Shimshon' (Sh), and '53006' (r53), characterized by high, moderate, and low compatibility, respectively. The non-grafted melon cultivar Ki was used as the control. The incompatible combination Ki/r53 gave the lowest fruit yield and the lowest average fruit weight. In that combination, the content of total ortho-diphenols increased vs. Ki and Ki/TZ and that of total flavonoids decreased vs. Ki/Sh. In addition, concentrations of the amino acids, glutamate, methionine, valine, alanine, glycine, and serine, increased in the pulp of the two compatible combinations, i.e., Ki/TZ and Ki/Sh, suggesting that rootstock identity and compatibility with melon Ki scion modulated amino acid synthesis. Our results show an association between rootstock identity (and level of compatibility with the scion) and an enhancement of fruit nutritional values, i.e., high concentrations of organic acids (determined as citrate, malate, fumarate, and succinate) and soluble carbohydrates (sucrose) were recorded in the pulp of the two compatible combinations, i.e., Ki/TZ and Ki/Sh.

CmMYB44 might interact with CmAPS2-2 to regulate starch metabolism in oriental melon fruit

Sugar content is one of the determining factors for melon fruit maturity. Studies have shown that starch gradually degrades during fruit ripening, resulting in sugar accumulation. But the specific relationship between starch metabolism and sucrose accumulation was still unknown. Here, the starch and sugar contents, the activities of key enzymes and the expression patterns of genes related to starch-sucrose metabolism were determined in the fruit of high sugar and starch variety ‘HS’ and low sugar and starch variety ‘LW’. It was found that starch accumulated during fruit development process, and then degraded at 30 days after anthesis (DAA), which was synchronized with sucrose accumulation in ‘HS’ fruit, while starch and sucrose contents were always at a lower level during ‘LW’ fruit maturation. Furthermore, starch metabolism-related enzymes (Adenine dinucleotide phosphate -glucose pyrophosphorylase (AGPase), α-amylase (AMY), β-amylase (BMY)) and the key enzymes for sucrose accumulation (sucrose phosphate synthase (SPS) and sucrose synthase (SS)) were significantly increased at ripening stage of ‘HS’ fruit, and their activities were consistent with the expressions of CmAPS2-2, CmAMY2, CmBAM1, CmBAM9 and CmSPS1. However, the contents of starch and sucrose and the activities of AGPase and SPS in ‘LW’ fruit didn't change significantly. We discovered an R2R3-type MYB transcription factor, CmMYB44, screened from yeast one hybrid library, could directly bind to the promoter of CmAPS2-2 to inhibit its transcription. These results revealed that the targeted down-regulation of CmAPS2-2 by CmMYB44 might be involved in the starch accumulation process, which affect the flavor quality of oriental melon fruit.