Identification of a novel stripe rust resistance locus in a Chinese wheat landrace by bulked segregant analysis of recombinant inbred lines combined with the 660 K SNP array
摘要
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a globally devastating wheat disease. Identifying and deploying new resistance sources is critical for effective disease management. The Chinese wheat landrace Weishanbaikeyangmai (BKYM) confers high resistance to prevalent Pst races in China, making it a valuable genetic donor for resistance breeding. In this study, a recombinant inbred line (RIL) population was developed from a cross between the susceptible landrace Deqinsuozhu (DQSZ) and BKYM for genetic analysis of stripe rust resistance. Using bulked segregant analysis (BSA) combined with the Wheat 660 K SNP array, a genomic region associated with resistance was identified on chromosome 5D. Kompetitive allele-specific PCR (KASP) markers were subsequently developed within this SNP-enriched region to construct a genetic linkage map. A stable quantitative trait locus (QTL), designated QYrbkym.sicau-5DL, was mapped to the 5DL chromosome, explaining 11.08–31.72% of the phenotypic variation. The QTL was delimited within a 5.06 cM interval flanked by markers KASP-BKYM-8 and KASP-BKYM-4, corresponding to a physical interval of 501.13–508.82 Mb in the Chinese Spring reference genome. This region harbors 16 annotated disease resistance-related genes, among which a leucine-rich repeat receptor-like kinase gene and two tandem kinase genes represent the most promising candidates underlying QYrbkym.sicau-5DL. This QTL likely represents a novel stripe rust resistance QTL and could serve as a valuable genetic resource to enrich wheat resistance gene pool. The associated KASP markers are expected to facilitate marker-assisted breeding for resistant cultivars.