Genotyping by Sequencing in Watermelon

• Published in: Genes Vol. 13; no. 12
• Main Authors: Yeo, Sang-Min, Hong, Jeongeui, Hossain, Mohammad Rashed, Jung, Hee-Jeong, Choe, Phillip, Nou, Ill-Sup
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.11.2022
• Subjects: Analysis; Bacterial diseases of plants; Diseases and pests; Genotype; Methods; Plant genetics; Quantitative trait loci; Watermelons; South Korea
• ISSN: 2073-4425; 2073-4425
• DOI: 10.3390/genes13122250

Watermelon (Citrullus lanatus), an economically important and nutritionally rich Cucurbitaceous crop grown worldwide, is severely affected by bacterial fruit blotch (BFB). Development of resistant cultivar is the most eco-friendly, cost-effective, and sustainable way to tackle this disease. This requires wider understanding of the genetics of resistance to BFB. In this study, we identified quantitative trait loci (QTLs) associated with BFB resistance in an F[sub.2] mapping population developed from BFB-resistant ‘PI 189225’ (Citrullus amarus) and -susceptible ‘SW 26’ (C. lanatus) genotypes based on the polymorphic markers identified by genotyping by sequencing (GSB). A linkage map covering a total genetic distance of 3377.1 cM was constructed. Two QTLs for BFB resistance, namely, ClBFB10.1 and ClBFB10.2, both located on chromosome 10 explaining 18.84 and 15.41% of the phenotypic variations, respectively, were identified. Two SNP-based high-resolution melting (HRM) markers WmBFB10.1 and WmBFB10.2 having high positive correlation with resistance vs. susceptible alleles were developed. The efficacy of the markers was validated in another F[sub.2] population derived from SW34 × PI 189225. The highest phenotypic variation was found in the locus ClBFB10.2, which also contains three putative candidate genes for resistance to BFB. These findings will accelerate the development of BFB-resistant watermelon varieties via molecular breeding.