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

Peanut (Arachis hypogaea L.) is a globally important oil crop. Web blotch, which is one of the most important foliar diseases affecting peanut, is responsible for serious yield losses worldwide. Breeding web blotch-resistant peanut varieties is considered to be 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. On the basis of 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 Chr16.12966357) linked to this gene were demonstrated to be co-segregated with the resistance of peanut web blotch proved by 72 randomly selected RIL recombinant lines, which could be used in marker-assisted breeding resistant peanut varieties.