Fine-mapping of a candidate gene for web blotch resistance in Arachis hypogaea L.

Abstract

Peanut (Arachis hypogaea L.) is a globally important oil crop. Web blotch is one of the most important foliar diseases affecting peanut, which results in serious yield losses worldwide. Breeding web blotch-resistant peanut varieties is the most effective and economically viable method for minimizing yield losses due to web blotch. In the current study, a bulked segregant analysis with next-generation sequencing was used to analyze an F2:3 segregating population and identify candidate loci related to web blotch resistance. Based on the fine-mapping of the candidate genomic interval using kompetitive allele-specific PCR (KASP) markers, we identified a novel web blotch resistance-related locus spanning approximately 169 kb on chromosome 16. This region included four annotated genes, of which only Arahy.35VVQ3 had a non-synonymous single nucleotide polymorphism in the coding region between the two parents. Two markers (Chr.16.12872635 and Chr.16.12966357) linked to this gene were shown to be co-segregated with the resistance of peanut web blotch by 72 randomly selected recombinant inbred lines (RIL), which could be used in marker-assisted breeding of resistant peanut varieties.