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Background: Moringa oleifera is a vegetable widely consumed because of its nutritional benefits such as proteins, vitamins minerals, antioxidant compounds, and vitamin E. While the plant leaves have been utilized to produce organic fertilizer or bio-extract, other parts such as stems, branches, or leaf petioles have often been discarded as waste. Methods: The present study evaluated different ratios (1:10; 1:20; 1:30; 1:40 and 1:50) and types of bio-foliar fertilizers (Moringa bio-foliar fertilizer, chitosan, and seaweed fertilizers) on yield, and quality in mustard green. The pot and field experiments were conducted in the spring seasons of 2019 and 2020 in completely randomized design using three replications. Result: The results showed that the mustard green yield and quality were affected by ratio and type of bio-foliar fertilizer in both seasons. Highest yield and quality was found for application of moringa bio-foliar fertilizer. The nitrate accumulation value (147.3 mg kg-1) found were also higher for moringa bio-foliar fertilizer but lower than the standard threshold. A strong relationship was found between economic yield (R2 = 0.82 to 0.95 in pots and field experiment (R2 = 0.78 to 0.81). In conclusion, moringa bio-foliar fertilizer at spraying ratio of 1:10 can be used to achieve higher yield and quality for mustard green.

Muskmelons are currently grown in several areas of Vietnam for domestic and international consumer markets. The fruit grows well in greenhouses in soil or soilless substrate such as coconut peat. Researchers in Vietnam are investigating the growth of muskmelons in a range of organic by-products. In this study, spent mushroom substrate was recycled for use as an organic substrate and to evaluate the growth, quality, and yield of three muskmelon varieties including RZ F1, PN 128, and TL3 in greenhouses over three months. The substrate was incubated for one month before use and contained 45% spent mushroom substrate, 30% manure, 7.7% rice husks, 1.5% phosphorus, 0.2% commercial Trichoderma (Tribac), 0.1% rice bran, 15% sand, and 0.5% micronutrients and water. Following incubation, the substrate had optimal pH for the growth of muskmelon and the concentration of nutrients and beneficial microorganisms had increased significantly. The growth of RZ F1 and TL3 cultivars was significantly better than PN 128 in terms of growth, fruit quality, and yield. Specifically, RZ F1 and TL3 species took 78 days and 75 days to complete their life cycle produced 1.76 kg and 1.62 kg of fruit, had a pericarp thickness of 4.0 cm, and possessed 14.20o Brix and 14.88o Brix of soluble solid content, respectively. These findings suggest that agricultural by-products, such as spent mushroom substrate, could be a valuable resource for the culture of muskmelons in Vietnam.

Moringa (Moringa oleifera Lam.) is a tree species with known value for food, medicine and water treatment. This study was conducted to: 1) evaluate promising moringa accessions from the World Vegetable Center; 2) select accessions adapted to growing conditions in central Vietnam; and 3) determine the influence of soil types, plant density and pruning height on biomass yield of moringa. The results showed that moringa accession VI08718 is the most adapted for growing in central Vietnam. It gained the highest yield (96.1 g plant-1) and highest mean number of branches at each harvest (3.9 branches). Moringa can grow in any soil type but it gained highest yield in alluvial soil (108.0 g plant-1). Biomass yield of moringa grown in sandy soil and fallow sandy soil was lower than in other soil types. However, improvement of sandy soil and fallow sandy soil resulted in high biomass yield comparable to yield in alluvial soil. Plant density of 160,000 plants ha-1 produced the highest yield (8.3 kg plot-1), whereas plants pruned at 55 cm from the soil surface obtained the highest yield (10.3 kg plot-1).

We report the development of a codominant sequence characterized amplified region (SCAR) marker linked to bacterial wilt resistance in tomato line Hawaii 7996. Bulked segregant analysis was employed for rapid identification of RAPD markers linked to resistance genes. Genomic DNA from six resistant F9 recombinant inbred lines (RILs) and six susceptible F9 RILs, which derived from a cross between S. lycopersicum Hawaii 7996 (resistant parent) and S. pimpinellifolium WVa 700 (susceptible parent) were pooled in to an R-pool and an S-pool, respectively. A total of 800 RAPD primers were screened and only six primers (UBC#176, 205, 287, 317, 350, and 676) showed polymorphism between R- and S- pools. Of these, only two markers UBC#176 and 317 revealed a 100% linkage in the individual plants comprising the contrasting bulks. Of these, the marker UBC#176 was converted into a codominant SCAR marker and designated as SCU176-534. The marker SCU176-534 was confirmed by genotyping the individual of the R- and S- pools and gave the same result as UBC#176. When the marker SCU176-534 was further validated for association with resistance and its potential for maker-assisted selection (MAS) in 92 tomato lines and cultivars, the results showed that none of these carries the resistance gene. Thus, SCAR marker SCU176-534 can be used in early selection of resistant lines when Hawaii 7996 is used as a parent in a breeding program.

Random amplified polymorphism DNA (RAPD) and bulk segregant analysis (BSA) approaches were used to characterize the molecular marker linked to the Phytophthora infestans resistance gene Ph-3 in tomato. A total of 800 RAPD primers were screened. One RAPD marker UBC#602 was identified to be tightly linked to the Ph-3 gene. The marker was successfully converted into a co-dominant sequence characterized amplified region (SCAR) marker. The SCAR marker SCU602 was used to ana- lyze 96 F2 progenies and fitted the expected 1:2:1 Mendelian segregation ratio. Forty one tomato inbred lines were screened using the SCAR marker in com- parison with a reference marker linked to the Ph-3 gene and both markers gave the same results. SCU602 was further validated for association to resis- tance and its potential in MAS in 72 tomato lines and cultivars. The marker identified three genotypes har- bouring the resistance allele. This SCAR marker can be used in breeding programs for the selection of the Ph-3 gene for Phytophthora infestans resistance.

Phytopthora root rot in pepper (C. annuum) is caused by Phytophthora capsici L., which exhibits a high level of pathogenic diversity. Resistance to this disease is conditioned by a number of quantitative trait loci. Pyramiding resistance alleles is desirable and could be simplified by the use of molecular markers tightly linked to the resistance genes. The purpose of this study was development of molecular markers linked to Phytophthora root rot resistance. An F8 recombinant inbred line (RIL) population derived from a cross between YCM334 and a susceptible cultivar ‘Tean’ was used in combination with bulk segregant analysis utilizing RAPD and conversion of AFLP markers linked to Phytophtora root rot resistance into sequence-characterized amplified region (SCAR) markers. In conversion: one marker was successfully converted into a co-dominant SCAR marker SA133_4 linked to the trait. In bulked segregant analysis (BSA): three RAPD primers (UBC484, 504, and 553) produced polymorphisms between DNA pools among 400 primers screened. Genetic linkage analysis showed that the SCAR and RAPD markers were located on chromosome 5 of pepper. Quantitative trait locus (QTL) analysis showed that the SA133_4 and UBC553 were linked to Phytophtora root rot resistance. These markers were correctly identified as resistant or susceptible in nine promising commercial pepper varieties. These markers will be beneficial for marker-assisted selection in pepper breeding.

Quantitative trait loci (QTL) for resistance to phytophthora root rot caused by Phytophthora capsici were investigated using two Korean P. capsici isolates and 126 F8 recombinant inbred lines derived from a cross of Capsicum annuum line YCM334 (resistant parent) and local cv. Tean (susceptible parent). The experimental design was a split plot with two replications. Highly significant effects of pathogen isolate, plant genotype, and genotype × isolate were detected. QTL mapping was performed using a genetic linkage map covering 1486·6 cM of the pepper genome, and consisted of 249 markers including 136 AFLPs (Amplified Fragment Length Polymorphisms), 112 SSRs (Simple Sequence Repeats) and one CAPS (Cleaved Amplified Polymorphic Sequence). Fifteen QTLs were detected on chromosomes 5 (P5), 10 (P10), 11 (P11), Pb and Pc using two data processing methods: percentage of wilted plants (PWP) and relative area under the disease progress curves (RAUDPC). The phenotypic variation explained by each QTL (R2) ranged from 6·0% to 48·2%. Seven QTLs were common to resistance for the two isolates on chromosome 5 (P5); six were isolate-specific for isolate 09-051 on chromosomes 10 (P10) and Pc, and two for isolate 07-127 on chromosomes 11 (P11) and Pb. The QTLs in common with the major effect on the resistance for two isolates explained 20·0–48·2% of phenotypic variation. The isolate-specific QTLs explained 6·0–17·4% of phenotypic variation. The result confirms a gene-for-gene relationship between C. annuum and P. capsici for root rot resistance.

The Bs2 gene of pepper (Capsicum spp.) confers resistance to the most commonly detected races of Xanthomonas campestris pv vesicatora (Xcv). Using information from a published database, we developed gene-based markers for selection of Bs2 in pepper. High polymorphism was detected in exon 3, intron 2 and 3’-UTR of the Bs2 gene. The three regions were sequenced and numerous SNPs and In/Dels were identified between resistant and susceptible inbred lines. Seven SNPs were selected to develop SNP markers using the tetra-primer amplification refractory mutation system-PCR methodology (Tetra-primer ARMS-PCR). One SNP (G/C) was used to develop a molecular marker that can perfectly identify the presence of the bacterial spot resistance. The gene-based markers were further validated to test association with resistance in 80 lines and cultivars. The markers successfully identified a bell pepper commercial cultivar 62-2 that harbors the Bs2 gene. The successful development of the markers in this study provides a useful tool for MAS to screen the Bs2 gene in pepper.

Sponge gourd varieties having aroma after cooking have been degenerated because of cross pollination. Collection and evaluation of sponge gourd germplasm are needed for conservation and breeding of high quality varieties. The objective of the study was to identify varieties having high yield, good quality and aroma under local conditions. Ten promising sponge gourd accessions, including A2, A6, A7, A13, A16, A17, B29, B30, HN and QN were evaluated for growth, morphological traits, fruit quality and yield. The experiment was carried out in Hue University of Agricultural and Forestry from June to October in 2014. The results showed that all promising accessions grew well. Different morphological traits were observed among promising lines. Yield of accessions A7, A13 and A17 were higher than the others. Only fruits of accession B29 had aroma after cooking. These lines can be used in sponge gourd breeding programs.

Five lines of introduced pepper obtained from National Institute of Horticultural and Herbal Science, Korea, namely YT1, YT2, YT3, YT4, KR1, and two local varieties, namely Chia Voi and Moi, were used in this study to evaluate bio-agronomy characteristics and yield components in summer-autumn season 2014 at Thua Thien Hue, Vietnam. The experiment was laid out in a random complete block design (RCBD) with three replications. The results showed that all of the introduced pepper accessions can grow under Thua Thien Hue condition. The introduced accessions as KR1, YT2 and YT4 showed good adaptability. These pepper lines had high yield and good fruit qualities, like Chia Voi. YT4 gave high number of leaves and plant height. Accession KR1 had the highest number of fruits per plant and yield (1397.8 kg/ha). Accession YT2 had high fruit setting rate and the biggest fruit (8.08 g). YT2 and YT4 had high yield, which were equivalent to Chia Voi. These accessions need to be conducted another trials in different areas and seasons to confirm their growth ability and can be used in crop structure at Thua Hien Hue province and breeding programs.