Cucumis Melo Research Articles

First Report of Natural Infection of Watermelon mosaic virus (WMV) Infecting Bottle Gourd and Snake Melon

Cucurbitaceous crops, one of the main crops of agriculture, are sensitive to many plant viruses. In August 2019, virus-like symptoms were observed on some cucurbit plants grown in private home gardens in Antalya and Denizli provinces (Turkey). A total of 53 leaf samples were sampled from plants with the most symptoms (melon (Cucumis melo L.), watermelon (Citrullus lanatus L.), bottle gourd (Lagenaria siceraria (Molina) Standl.), and snake melon (Cucumis melo var. flexuosus) and tested by Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) against possible watermelon mosaic potyvirus (WMV) infection. The coat protein gene (CP) specific primer sets amplified a gene product of nearly 820 bp fragment from symptomatic plants. WMV infections were detected in 31 individual cucurbit plants, including 11 melons, 8 watermelons, 7 snake melons and 5 bottle gourds. The presence of viral infection was found only in ornamental squash plants in Antalya province and in all cucurbits sampled in Denizli province. To better comprehend the molecular characteristics of virus isolates, the amplified viral DNA fragments were cloned in a proper prokaryotic plasmid, sequenced by Next Generation Sequencing (NGS) and recorded to GenBank. Bioinformatic analyses using the Basic Local Alignment Search Tool (BLAST) showed that the identified CP gene sequences exhibited significant nucleotide homogeneity, supported by a high nucleotide similarity index with that of other isolates around the world. In addition, Turkish isolates isolated from Antalya and Denizli regions showed approximately 94% nucleotide similarity among themselves. For phylogenetic inference, WMV sequences were subjected to multiple alignments with isolates from different geographic origins of the same viruses. Molecular phylogeny showed that all WMV isolates are closely related to other world WMV isolates at variable rates. WMV is wide host range viruses in cucurbit crops, however, this work is the first scientific report of WMV isolates detected in bottle gourd and snake melon from the South and West Regions of Turkey all over the world.WMV are broad spectrum viruses in cucurbit crops. This work is the first scientific report of Watermelon mosaic potyvirus isolates detected in bottle gourd and snake melon from the South-West Region of Turkey in all over the world.

First report of root rot in Trichosanthes kirilowii (Chinese cucumber) caused by Fusarium sulawesiense in China.

Trichosanthes kirilowii (Chinese cucumber) is one of the important perennial herbaceous vines in China, with putative pharmacological activities including anti-tumor and lowering blood lipids. In July 2022, T. kirilowii plants with brownish roots and chlorotic leaves were observed in several orchards in Qianshan, Anhui province, China (30°34'N, 116° 30'E). The disease incidence reached approximately 10% within an area spanning 20 ha, and was higher in poorly drained orchards. To investigate this root rot disease, five symptomatic plants were collected from the diseased orchards in Qianshan. Subsequently, small sections of the diseased roots were surface sterilized using 1% sodium hypochlorite and 75% ethanol for 45 seconds each. Then, sterilized roots were placed onto PDA (20% diced potato, 2% glucose, and 1.5% agar, and distilled water) and incubated at 28℃ in the dark for 6 days. A total of eight isolates with similar morphology were obtained and purified by single spore culturing. Two representative isolates (QSJ4 and QSJ5) were chosen for further analysis. When grown on PDA, the surface of each colony was white with dense aerial mycelium and pale orange color in the center with a white edge on the reverse side. Macroconidia produced on carnation leaf agar plates were falcate, slightly curved, and 3 to 5 septate, with papillate apical cells and indistinct basal cells. Macroconidia were 17.4-42.3 × 2.4-5.8 μm (n = 100). Microconidia were ellipsoidal in shape, slightly curved or not curved, and most were 1-septate, 9.6-16.7 × 1.5-3.8 μm (n = 40). The identity was determined by sequencing four loci (i. e., ITS, CAL, EF1-α and RPB2) from two representative isolates (Liu et al. 1999; O'Donnell et al. 1998, 2000; Reeb et al. 2004; White et al. 1990). Sequences were deposited in GenBank [ITS (OR267397, OR267398), CAL (OR296634, OR296635), EF1-α (OR296637, OR296638) and RPB2 (OR296640, OR296641)]. A phylogenetic analysis was performed with three loci (CAL, EF1-α, RPB2) comprising a concatenated dataset of 68 strains in the Fusarium incarnatum-equiseti species complex (Han et al., 2023). The results showed that isolates QSJ4 and QSJ5 clustered closely together with reference strains of F. sulawesiense. Pathogenicity tests were conducted by inoculating three-week-old healthy T. kirilowii seedings (cv. Wanlou No. 9) cultivated in substrate soil in pots with a diameter of 17 cm and a height of 10.5 cm. A 20 mL aliquot of spore suspension (106 conidia/mL) of F. sulawesiense was inoculated to the roots of potted seedlings by irrigation. Each strain was inoculated onto three seedlings. The potted seedlings were inoculated with sterile water as the negative control. Inoculated seedlings were incubated in a growth chamber at 25℃ and 75% relative humidity. After one week, typical symptoms of root necrosis and leaf chlorosis were observed on the inoculated seedlings. Disease symptoms were not observed on the control seedlings. All seedlings showing root necrosis and leaf chlorosis caused by the inoculations were subjected to fungal isolation, and the results showed that the reisolated colonies matched the inoculated ones for morphologies and ITS sequences. Fusarium sulawesiense has been previously reported to cause disease on Cucumis melo L. in Brazil (Medeiros Araujo et al. 2021), Musa acuminata Colla in south Sulawesi (Maryani et al. 2019), Luffa aegyptiaca Miller and Musa nana Lour. in China (Wang et al. 2019). To our knowledge, this is the first report of F. sulawesiense causing Fusarium root rot of T. kirilowii in China.

Time-Series Transcriptome of Cucumis melo Reveals Extensive Transcriptomic Differences with Different Maturity.

As the most important melon cultivar grown in the north-western provinces of China, Hami melon (Cucumis melo) produces large edible fruits that serve as an important dietary component in the world. In general, as a climacteric plant, melon harvested at 60% maturity results in a product with bad quality, while the highest-quality product can be guaranteed when harvesting at 90% maturity. In order to clarify the genetic basis of their distinct profiles of metabolite accumulation, we performed systematic transcriptome analyses between 60% and 90% maturity melons. A total of 36 samples were sequenced and over 1.7 billion reads were generated. Differentially expressed genes in 60% and 90% maturity melons were detected. Hundreds of these genes were functionally enriched in the sucrose and citric acid accumulation process of C. melo. We also detected a number of distinct splicing events between 60% and 90% maturity melons. Many genes associated with sucrose and citric acid accumulation displayed as differentially expressed or differentially spliced between different degrees of maturity of Hami melons, including CmCIN2, CmSPS2, CmBGAL3, and CmSPS2. These results demonstrate that the phenotype pattern differences between 60% and 90% maturity melons may be largely resulted from the significant transcriptome regulation.

Comparative Transcript Levels of Sugar Metabolism Genes Between the Canary Melon and a Vietnamese Non-Sweet Melon Cultivar

Two different melon cultivars, Canary and Vietnamese non-sweet melons, are used to compare the fruit's sweetness levels. The results indicate that the Canary melon is much sweeter than the non-sweet melon. The transcript levels of the sugar metabolism genes, including <em>Cucumis melo ACID INVERTASE 2</em> (<em>CmAIN2</em>) and <em>SUCROSE SYNTHASE 1</em> (<em>CmSUS1</em>), are examined in two fruit tissues. PCR using cDNA and the electrophoresis assays indicate that the <em>CmAIN2</em> and <em>CmSUS1 </em>primer sets are specific, and only one band of PCR product is obtained from all tested samples. The quantitative reverse transcription PCR (RT-qPCR) assay is applied to compare the transcript levels of the <em>CmAIN2</em> and <em>CmSUS1 </em>genes in fruit tissues of the Canary and the Vietnamese non-sweet melons. Consistent with the sweetness levels, the <em>CmAIN2 </em>and <em>CmSUS1 </em>transcript levels are higher in the Canary melon than those in the non-sweet melon. These results imply that the local sugar metabolism in the fruits may also play an essential role in determining fruit sweetness. In addition, practically, the transcript levels of the <em>CmAIN2 </em>and <em>CmSUS1 </em>genes can be accessed and used to predict the sweetness of melon fruits early.

Antioxidant Activity in Melon (Cucumis melo L. 'Gama Melon Parfum') AS Antiaging Cream Formulation

Antiaging cosmetics are becoming increasingly popular among the general public. Melon (Cucumis melo L.) Gama Melon Parfum cultivars ('GMP') are one of the plants that can be utilized as a basic ingredient in the production of antiaging cosmetics. 'GMP' melon has cucurbitacin compounds that can be utilized as antiaging and contains flavonoid, saponin, and terpenoid compounds that have antioxidant properties. This research aims to analyze the difference in antioxidant activity of 'GMP' melon extract and 'GMP' melon cosmetic cream preparation cultivated in Yogyakarta with 'GMP' melon cultivated in Bandung, analyze extract standardization parameters, and determine the phenolic and flavonoid contents of each melon extract contains. The activity of antioxidants was determined by the DPPH method, the Folin-Ciocelteu method to measure phenolics, and the AlCl3 solution-based colorimetric approach to measuring flavonoid content. It was revealed that the highest % RSA of antioxidant activity is in ‘GMP’ melon extract cultivated in Bandung. The results of the standardization of 'GMP' melon extract met the requirements of standard parameters. The greatest total phenolic content is derived from the extract of ‘GMP’ melon in Bandung, while the highest total flavonoid content in 'GMP' melon extracts is cultivated in Yogyakarta. The highest to lowest antioxidant activity of ‘GMP’ melon cream was formula IV (‘GMP’ melon extract 30% cultivated in Bandung), formula III (‘GMP’ melon extract 20% grown in Bandung), formula II (‘GMP’ melon extract 30% cultivated in Yogyakarta), formula I (‘GMP’ melon extract 20% cultivated in Yogyakarta), and the lowest is in K- with formula without ‘GMP’ melon extract.

Genome-wide identification of the expansin gene family in netted melon and their transcriptional responses to fruit peel cracking.

Fruit cracking not only affects the appearance of netted melons (Cucumis melo L. var. reticulatus Naud.) but also decreases their marketability. Herein, to comprehensively understand the role of expansin (EXP) proteins in netted melon, bioinformatics methods were employed to discover the EXP gene family in the melon genome and analyze its characteristic features. Furthermore, transcriptomics analysis was performed to determine the expression patterns of melon EXP (CmEXP) genes in crack-tolerant and crack-susceptible netted melon varieties. Thirty-three CmEXP genes were identified. Chromosomal location analysis revealed that CmEXP gene distribution was uneven on 12 chromosomes. In addition, phylogenetic tree analysis revealed that CmEXP genes could be categorized into four subgroups, among which the EXPA subgroup had the most members. The same subgroup members shared similar protein motifs and gene structures. Thirteen duplicate events were identified in the 33 CmEXP genes. Collinearity analysis revealed that the CmEXP genes had 50, 50, and 44 orthologous genes with EXP genes in cucumber, watermelon, and Arabidopsis, respectively. However, only nine orthologous EXP genes were observed in rice. Promoter cis-acting element analysis demonstrated that numerous cis-acting elements in the upstream promoter region of CmEXP genes participate in plant growth, development, and environmental stress responses. Transcriptomics analysis revealed 14 differentially expressed genes (DEGs) in the non-cracked fruit peels between the crack-tolerant variety 'Xizhoumi 17' (N17) and the crack-susceptible variety 'Xizhoumi 25' (N25). Among the 14 genes, 11 were upregulated, whereas the remaining three were downregulated in N17. In the non-cracked (N25) and cracked (C25) fruit peels of 'Xizhoumi 25', 24 DEGs were identified, and 4 of them were upregulated, whereas the remaining 20 were downregulated in N25. In the two datasets, only CmEXPB1 exhibited consistently upregulated expression, indicating its importance in the fruit peel crack resistance of netted melon. Transcription factor prediction revealed 56 potential transcription factors that regulate CmEXPB1 expression. Our study findings enrich the understanding of the CmEXP gene family and present candidate genes for the molecular breeding of fruit peel crack resistance of netted melon.

The Effectiveness of Vermicompost and NPK Fertilizer Treatment on Cucumis melo L. Vegetative Growth

Melon is an annual plant, growing creeping with a stem length of about 3 meters. The vegetative and generative growth of melons is influenced by genetic and environmental factors. Environmental factors that affect the growth of melons include the abundance of nutrients in the growing media. Research has been carried out on the effectiveness of vermicompost and NPK fertilizer treatment on melon vegetative growth, with the aim of analyzing the effectiveness of vermicompost in increasing stem length, number, length and width of leaves and stem diameter of melons. effectiveness of NPK fertilizer in increasing stem length, number, length and width of leaves and stem diameter of melons. Effectiveness of the interaction of vermicompost and NPK fertilizer in stimulating melon growth. Growth parameters were measured when the melon was 28, 29 and 30 days after planting, the data obtained was analyzed using Anova. The results showed that vermicomposti is effective in increasing stem length, total and leaf length, but is not effective in increasing leaf width and stem diameter of melons. Application of NPK fertilizer is effective in increasing stem length, total leaves, leaf length, leaf width and stem diameter of melon. The interaction between vermicompost and NPK fertilizer was not effective in stimulating melon growth.

Effects of Genotype and Modified Atmosphere Packaging on the Quality of Fresh-Cut Melons.

Marketing melons (Cucumis melo) as convenient fresh-cut products is popular nowadays. However, damage inflicted by fresh-cut processing results in fast quality degradation and food safety risks. The life of fresh-cut produce can be extended by a modified atmosphere (MA), either generated in a package by tissue respiration (a passive MA) or injected by gas flushing (an active MA). This work investigated the effect of passive and active MA formed in packages of different perforation levels on the quality of fresh-cut melons of two genetic groups: C. melo var. cantalupensis, characterized by climacteric fruit behavior, and non-climacteric C. melo inodorus. The best product preservation was achieved in passive MA packages: non-perforated for inodorus melons and micro-perforated for cantalupensis ones. The optimal packages allowed for the preservation of both genotypes for 14 days at 6-8 °C. The major factors limiting the shelf life of fresh-cut melons were microbial spoilage, translucency disorder and hypoxic fermentation associated with cantalupensis melons with enhanced ethyl acetate accumulation. Inodorus melons were found to be preferable for fresh-cut processing since they were less prone to fermented off-flavor development.

Perendaman Benih Melon Dengan PGPR Pseudomonas sp. dan Bacillus sp. di Dusun Ngadilegi Utara, Kecamatan Pandaan, Kabupaten Pasuruan

Ngadilegi Utara Hamlet is one of the hamlets in Plinlahan Village, Pandaan District, Pasuruan Regency which has large potential land for cultivating plants. Farmers in Ngadilegi Hamlet grow many crop commodities, one of which is melons. Melon (Cucumis melo L) is an annual fruit plant originating from the Persian Hot Valley or the Mediterranean region which is the border between West Asia, Europe and Africa. Melon plants are a type of pumpkin plant which is in the same family as watermelon, cantaloupe and cucumber. One effort to increase melon production in North Ngadilegi Hamlet can be done by good development and correct cultivation technology and supported by the use of new technology, namely the use of bacteria contained in PGPR. Soaking seeds with PGPR aims to ensure that the bacteria contained in PGPR are able to colonize the seeds as early as possible. Proper long soaking treatment of seeds can increase plant yields because bacteria will bind to the seed coat and imbibition into the seeds.

Discrimination of Thai melon seeds using near-infrared spectroscopy and adaptive self-organizing maps

Melon (Cucumis melo L.) is a popular fruit consumed around the world. It has significant economic value as a crop, export product, and source of essential nutrients. Thus, using high-quality, authentic seed varieties is the first step toward achieving impactful agricultural production. Unfortunately, distinguishing between seed varieties using only human perception can be difficult because of their similar traits. Thus, dishonest distributors may trade low-quality seeds for high-quality seeds. In this study, seeds from five Thai melon varieties, Singapore Thai melon (ST), Nan Thai melon (NT), Round Thai melon (RT), Striped Singapore Thai melon (SST), and Golden and Long Thai melon (GLT), were classified using a distinctive discrimination method that combines modified self-organizing maps (SOMs) with near-infrared (NIR) spectroscopy. The physical characteristics, morphology, and thermal behavior of the seeds were also examined through optical microscopy, scanning electron microscopy, and thermogravimetric analysis, respectively. Attenuated total reflection–Fourier transform infrared, and NIR spectroscopy revealed that different varieties of melon seeds possess significant variations in lignin content and carbohydrate composition. Seed samples from the five Thai melon varieties were further classified using a modified SOM map created with optimized scaling value, map size, and a number of iteration parameters. Binary classification with the One vs Rest strategy and multiclass classification was performed to verify the constructed classifier model. The supervised SOMs developed herein can achieve the multiclassification of seed types effectively and efficiently, with a high accuracy of 95.52 % for the training set and 91.59 % for the test set, which were significantly superior to those of well-established discrimination models.

The effects of different rootstocks on aroma components, activities and genes expression of aroma-related enzymes in oriental melon fruit.

Grafting is widely applied in the cultivation of melon. In this study, 'Qinmi No.1' (Cucumis melo L.(QG)) and 'Ribenxuesong' (Cucurbita maxima Duch. (RG)) were used as rootstocks for 'Qingxin Yangjiaocui' (Cucumis melo L.). The results showed that grafting with muskmelon rootstocks had no significant effect on fruit aroma, but grafting with pumpkin rootstocks significantly reduced the odor intensity and odor preference scores of melon fruits. Compared with the fruits from self-grafted plants (SG), four new aromatic volatiles with a sweet smell were detected, the alcohol dehydrogenase (ADH) activity was significantly decreased at 30 DAP, but unaffected at 42 DAP in QG fruits. There was no difference for alcohol acetyltransferase (AAT) activity between QG and SG fruits. The expression level of CmADH2 was significantly higher at 30 DAP and 42 DAP, but CmAAT2 was significantly lower at 42 DAP in QG fruits compared with SG fruits. In RG fruits, the main aroma compounds including butanoic acid ethyl ester, 2-methyl-2-butene-1-al, and 2-methylheptan-1-al were absent, while the volatile compounds with unpleasant odor characteristics including trans, cis-2,6-nonadien-1-ol, (E,E)-2,4-heptadienal, octanoic acid, and styrene were detected. Compared with SG fruits, 1-nonanol and 1-heptanol with green odor characteristics were significantly increased, but eucalyptol and farnesene with fruity aroma characteristics were significantly decreased in RG fruits. The ADH activity of RG fruits was significantly lower than that of SG fruits at 30 DAP and the AAT activity was significantly lower than that of SG fruits at 42 DAP. In addition, the expression levels of CmADH and CmAAT homologs in RG fruits were significantly lower than those in SG or QG fruits. These results show that grafting with pumpkin rootstocks affected the main aroma components, reduced ADH and AAT activities, and down-regulated the expression levels of CmADHs and CmAATs in the melon fruits. This study reveals the mechanism of different rootstocks on melon fruit aroma quality, and lays a theoretical foundation for the selection of rootstocks in melon production. Future studies using overexpression or CRISPR/CAS system to obtain stable transgenic lines of genes encoding key aromatic volatiles, would be promising to effectively improve the flavor quality of melon.

Seasonal Autoregressive Integrated Moving Average (SARIMA) for Melon (Cucumis melo) Yield from 2011 to 2020 Based on Planting Date Period

The main goal of time series modelling is to collect and analyze past values to develop appropriate models that describe the inherent structure and characteristics of the series about the planting date of melon. The data used in this study are the melon yield based on twenty-nine days of planting date in March from the first to the last planting date of March 2011 to 2020, to evaluate the prediction performances of the models, two indices: the root mean squared error (RMSE) and mean absolute percentage error (MAPE) were used to compare the forecasting capabilities of the SARIMA models, Excel was used first for preparing as CSV file and then changed to time series data to make the dataset of yield and R version 4.0.2 (the R Development Core Team) was used to perform ETS and SARIMA models For planting date time series based on yield, seasonal autoregressive integral moving average models (SARIMA) were constructed. The Student's t-test was one of the statistical tests used to evaluate the effectiveness and validity of the SARIMA models Through the use of SARIMA models, it is feasible to create synthetic records that maintain the statistical properties of the historical record. Finally, the results can be applied to different planting dates based on yield. Based on the Bayesian Information Criteria (BIC) values and the overall highest R2 values of 0.94, the optimal SARIMA (0,1,1) model was chosen. No limitations were found. It is the first time that this mathematical method was used to analyze time series data for 10 years of planting date of melon and it could be useful for agronomists and horticulturists to choose the best model.

Application of sodium alginate-based edible coating with citric acid to improve the safety and quality of fresh-cut melon (Cucumis melo L.) during cold storage.

The safety and quality of fresh-cut melons is reduced by a series of decay processes by enzymatic browning and microbial contamination. This study aimed to assess the impact of a 2% sodium alginate-based edible coating (ALC) combined with different concentrations of citric acid (CA; 0.5%, 1%, 2%, and 3%) on the microbial safety and physical quality of fresh-cut melons during a 7-day storage period at 10°C. The findings revealed that the combination of ALC and 3% CA was successful in preventing the growth of pathogenic bacteria (Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus) and natural microflora on fresh-cut melons during storage. In addition, treating fresh-cut melons with ALC containing 3% CA improved their quality by reducing browning and softening during storage at 10°C. Based on these findings, it can be concluded that using ALC with 3% CA is an effective method to improve the safety and quality of fresh-cut melons.

First report of Lasiodiplodia brasiliensis causing root rot in melon plants in northeastern Brazil.

Melon (Cucumis melo L.) is the second most exported fruit in Brazil with an annual production of 27.5 million tons (FAO 2023). From September 2019 through February 2020, 50-day-old melon plants started showing root rot symptoms (dark-brow necrotic zones in their roots that extended to the collar zone) in northeastern Brazil, 30% of the plants in the fields were affected by the disease. The fields are in clay soil where melon, in monoculture, is produced all year long with three cycles of the culture per year. A total of 132 samples from "Yellow" and "Cantaloupe" cultivars were collected from four melon fields (4°59'45.3"S, 37°33'39.7"W; 4°57'10.2"S, 37°31'37.1"W; 5°38'17.9"S, 37°56'27.7"W; and 5°00'25.5"S, 37°23'55.3"W). Small pieces of diseased tissues were surface disinfested in 70% ethanol for 30 sec, in 2% sodium hypochlorite for 1 min, washed in sterilized distilled water, plated on a PDA Petri dishes with tetracycline (0.05g/L), and incubated for seven days at 28 ± 2 ºC. Nine representative isolates were selected for downstream analysis. Colonies were white and later became dark gray, pycnidia and conidia were produced after 30 days ofncubation at 25°C under near-UV light in water-agar medium. Conidia were hyaline when immature and dark brown when mature, ranging from cylindrical subovoid to ellipsoidal and septate to non-septate, and with an average size of 12.54 to 21.97 µm. The colonies were morphologically identified as Lasiodiplodia sp. (Phillips et al. 2013). Total DNA from the isolates was extracted and the ITS, TUB, and TEF-1α genes (Jayawardena et al. 2019) were partially amplified by PCR, Sanger sequenced, and deposited in Genbank: ITS (OM102511 to OM102520), TUB (OR062087 to OR062094 and OR062095), and TEF-1α (OP536826 to OP536835). Blastn analysis of the partial sequences ITS (519bp), TUB (388bp), and TEF-1α (315bp) showed 100% nucleotide similarity of the isolates with sequences of L. brasiliensis and L. theobromae from the GenBank. A phylogenetic tree was constructed using the Maximum Parsimony Analysis method. All nine isolates were grouped into the L. brasiliensis clade with 71% bootstrap support, confirming the isolates's identity. Pathogenicity assays were conducted in a greenhouse using the wooden toothpick inoculation method (Nogueira et al. 2019). "Goldex" Yellow melon seedlings were used in a completely randomized experimental design, with 10 treatments (9 isolates + Mock) and six replicates, with one plant per pot. Plants were inoculated 15 days after sowing, and disease severity was evaluated 50 days after inoculation. All nine isolates caused symptoms in the assessed melon plants. The fungus was reisolated from the lesions and looked morphologically identical to the inoculated fungus, fulfilling Koch's postulates. The pathogenicity test was repeated and yielded similar results. All samples in this study were provided by melon growers who were concerned about the high incidence of root rot disease in their plantations. More research needs to be conducted to determine the epidemiology and the extension of the economic impact caused by this pathogen to melons to develop strategies for disease control to properly assist the growers's concerns. This pathogen has been reported to cause disease in other crops in Brazil, e.g., watermelon (Alves et al. 2023) and apples (Martins et al. 2018). However, to the best of our knowledge, this is the first report of L. brasiliensis causing root rot in melons in Brazil.

First report of Brown blotch disease caused by Diaporthe ueckeri on Hyophorbe lagenicaulis in China.

Bottle palm (Hyophorbe lagenicaulis) is a picturesque evergreen plant in the family Aceraceae, ubiquitously cultivated as an ornamental tree throughout the tropics and subtropics due its attractive shape and small stature. During 2016-2022, brown spots were observed on the leaves of bottle palm on both sides of a campus road in Mazhang, Zhanjiang, Guangdong province (N21°8' 59.9" E110°17' 51.4"). Symptoms appeared as circular, light yellow to brownish red, slightly sunken spots, and brown to black in the center (Fig 1 A-C). The spots expanded to big irregular blotches, which finally led leaves to wither. 0ne hundred percent of 50 plants were infected and 90% of the leaves each plant were covered with brown patches of different sizes. Tissues (5 × 5 mm) from the diseased-healthy junction of the leaf spots were surface disinfected with 75% ethanol for 30 s and 3.5% hydrogen peroxide solution for 5 min, rinsed three times with sterile water and placed on potato dextrose agar (PDA) at 25-28℃ in the dark for 3 days. Fungi with the similar morphology grew from 100% of these inoculated tissues. Hyphal tips from the colony edges were transferred to PDA. Single isolates were obtained by plate dilution method after sporogenesis. Colonies with sparse aerial mycelium were flat, grey. Conidiomata were superficial, black, solitary, scattered. Conidiophores were cylindrical, densely aggregated. Alpha conidia with bi-multiguttulate were hyaline, smooth, ellipsoidal, aseptate, 4.7-7.9×1.6-3.4 µm (Av. 6.4×2.3µm, n>50). Beta conidia were filiform, slightly curved, 15.9-28.3× 0.7-1.1 μm (20.1 × 0.9 μm, n>50) (Fig 1 E-H). Gamma conidia were not observed. The internal transcribed spacer (ITS) regions, large subunit (LSU) rRNA sequence, translation elongation factor (TEF), actin (ACT), calmodulin (CAL), histone H3 (HIS), and beta tubulin (TUB2) genes were amplified using the primers ITS4/ITS1 (White et al. 1990), LR0R/LR5, EF1-728F/EF-2, ACT-512F/ACT-783R, CAL228F/ CAL737R, CYLH3F/ H3-1b, and TUB2Fd /TUB4Rd (Aveskamp et al. 2009; Carbone and Kohn 1999; Crous et al. 2004; O'Donnell et al. 2000), respectively. All seven sequences of the isolate CCAS-JPYZ-4B (ACCC 35493) were submitted to NCBI (OR430112-3, OR451702-6). BLAST search result showed high sequence identity with several Diaporthe ueckeri isolates (Tab1). Phylogenetic analysis of the concatenated data of CAL, HIS, ITS, TEF and TUB genes using Maximum Likelihood method placed CCAS-JPYZ-4B in the D. ueckeri clade. Thus, the isolate was identified as D. ueckeri (Udayanga et al. 2015). Pathogenicity tests were performed on three 5-year-old plants, one healthy new leaf per plant and 10 sites on per leaf were slightly wounded and inoculated with 5-mm mycelial plugs from 10-day-old culture on PDA. The control sites were treated with PDA plugs. Each inoculated leaf was covered with a plastic bag to maintain high humidity and kept at natural temperatures (25-28 ℃). The experiment was repeated once. Symptoms appeared as those described as above 5 to 10 days after inoculation (Fig 1 D). Controls were asymptomatic. The fungus was reisolated from diseased leaves and identified as D. ueckeri. D. ueckeri may infect Arachis hypogaea, Cucumis melo, Camellia sinensis, Glycine max, Mangifera indica and Michelia shiluensis, and this is first report causing brown blotch on bottle palm in China. This disease occurred all year round, which seriously affected plants growth and ornamental value; it is necessary to develop an effective management strategy.

First Report of Bacterial Leaf Spot on Muskmelon Caused by Pseudomonas syringae pv. syringae in China.

Muskmelon (Cucumis melo L.) is one of the most widely cultivated and economically important fruit crops in the world. In January 2023, muskmelon leaves of cultivar 'Sheng Gu' were observed with irregularly shaped spots in four nurseries in Wanxiang Village, Pudong District of Shanghai, China. Initial symptoms were irregular soaking on the leaves, which progressed to rotting and necrotic spots. The disease incidence of melon seedlings in different nurseries ranged from 10 to 25%. To isolate and identify the causal agent, the small pieces of lesion tissues (5×5 mm) from symptomatic leaves were sterilized in 75% ethanol for 30 s and rinsed three times with sterile water. Following that, tissues were crushed with sterile glass rod in a sterile 2.0 mL centrifuge tube containing 100 μl of sterile water. The suspension was serially diluted before being spread on Luria-Bertani (LB) medium. After 48 h of incubation at 28°C, the cream-colored bacterial colonies from the 10-4 dilution were tiny and purified by streaking on new LB plates. To confirm the species identity of the bacterial isolates, genomic DNA was extracted from four independent representative colonies from different diseased plants, and several conserved genes were amplified and sequenced, including the 16S rRNA gene with primers 27F/1492R, gyrB gene with primers gyrBFor2/gyrBRev2, and rpoD gene with primers rpoDFor2/rpoDRev2 (Lelliot et al. 1966; Murillo et al. 2011). The results showed that the four colonies were identical. Using BLAST analysis in GenBank, the 16S rDNA (accession no. OQ659765, 1,402 bp), the gyrB (accession no. OQ708618, 911 bp), and rpoD sequences (accession no. OQ708619, 798 bp) showed 99.86-100% homology with 99-100% coveage as the corresponding gene sequences in the P. syringae pv. syringae strain HS191 (accession no. CP006256.1). The bacterial isolate was designated as P. syringae pv. syringae strain PDTG. Phylogenetic tree analysis of 16S rDNA, gyrB and rpoD genes further verified that the bacteria isolate was in close proximity to P. syringae pv. syringae. Additionally, all four isolates were detected in PCR with P. syringae pv. syringae specific primers, PsyF/ PsyR (Borschinger et al. 2016; Guilbaud et al. 2016). Ten two weeks old healthy 'Sheng Gu' muskmelon seedlings were inoculated by spraying with a bacterial suspension of 108 CFU/ml, and ten additional healthy plants treated with sterilized water served as the control. The inoculated plants were maintained at 25°C and 75% relative humidity for 7 days in artificial climate room. Water-soaked rot, similar as those seen in the nurseries, appeared on leaves 7 days after inoculation (dai), while the leaves of control plants remained healthy. The bacteria were re-isolated from rot of inoculated leaves and confirmed as the original pathogen by PCR with the PsyF/ PsyR primers and the 16S rRNA gene sequences. To our knowledge, this is the first report of P. syringae pv. syringae causing bacterial leaf spot on muskmelon in China, and this report expands the host range of P. syringae pv. syringae.

“Farming with alternative pollinators” provides benefits also in large-scale fields

Insect pollinators are declining worldwide due to many challenges and several approaches have been implemented to mitigate their loss. Farming with Alternative Pollinators (FAP) uses marketable habitat enhancement plants (MHEP) that yield substantial benefits for farmers from the first year. Studies with small-scale farmers have shown that FAP sustains high diversity and abundance of flower visitors and natural enemies, resulting in significant increases in smallholders' incomes, on average 121% higher. For the first time, we analyzed this approach in large-scale fields. Trials were conducted in 16 farms in two regions of Morocco, Sidi Slimane and Ksar El-Kebir, in 2021. We used melon (Cucumis melo) as the main crop and coriander, anise and sunflower as MHEP and selected in each farm 1 ha as trial area in larger monocultures. We compared FAP and control fields regarding abundance and richness of flower visitors, natural enemies and pests as well as net income of the whole field (1 ha). Flower visitors and natural enemies were significantly more diverse and abundant in FAP fields and there were also fewer pests. Our economic results show 17% higher net income per ha in FAP fields versus control fields in the Ksar El-Kebir region, and 12% higher net income in FAP fields compared to control fields in Sidi Slimane region. Although the mean yield difference was statistically significant, the income difference was not. We suggest more FAP trials are needed in different large-scale fields systems.

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.

Biomass derived Cu2O nanoparticles for N-atom insertion reactions: a base-free synthesis of quinazolinones with a green approach

This work describes the use of an eco-friendly biogenic approach for the synthesis of Cu2O NPs utilizing Cucumis melo peel extract for the first time and employed for the one-pot multicomponent synthesis of quinazolinones in a green solvent.

Exploration of Two Cucurbitaceae Fruit (Muskmelon and Watermelon) Seeds for Presence of Phytochemicals, and Antioxidant and Antimicrobial Activities

Cucurbitaceae family fruits, especially melons, offers significant quantities of minerals carotenoids and phenolic compounds, contributing to their antioxidant activity. However, seeds of these fruits are usually discarded as waste by products. In current study, seeds of watermelon (Citrullus lanatus) and muskmelon (Cucumis melo) were separated, dried, grounded and extracted, with 70% ethanol, to investigate total phenolic content (TPC), flavonoid content (TFC), carotenoid content (TC) content, and total antioxidant activity (TAA). Further, antimicrobial activities of these extracts were tested against selected bacterial and fungus strains. Results showed that extracts of both cucurbits presented significant amounts of phytochemicals, with higher quantities presented by watermelon seeds. In watermelon seeds, TPC were found 156.50 mg/GAE 100 g, TFC 56.78 mg CE/100 g, TC 36.65 mg/100 g, and TAA 71%, and these amounts were significantly higher than those found in muskmelon seeds. Antimicrobial study results showed that extracts of both seeds exhibited significant zone of inhibitions against three bacterial and three fungal species, and these values were very comparable to the reference antimicrobial drug used, Ciprofloxacin. Findings of current research work provided significant grounds for presence of phytochemical bioactives in two melon fruits seeds, providing the basis for extraction and utilization of these bioactives, through processing and fortification different pharma foods.