Genetic analysis of stripe rust resistance in CIMMYT common wheat line KFA/2*KACHU under Chinese rust environment

Abstract Breeding resistant wheat variety is the most economic and efficient way to manage wheat stripe rust, while identification of new stripe rust resistance gene and development the molecular markers will be very useful for wheat breeder in the breeding program. In the present study, a recombinant inbred line (RIL) population derived from a cross of the resistant parent KFA/2*KACHU and susceptible parent Apav#1 was used to map stripe rust resistance loci. In combination of GBS genotyping platform and BSR-Seq method, we mapped a new race-specific stripe rust resistance gene on wheat chromosome 5BL at the seedling stage, temporarily named as YrK. TraesCS5B02G330700 encoded a receptor-like kinase was considered as the key candidate gene of YrK based on virus induced gene silencing (VIGS) method. Its expression showed a significant up-regulated at 24h after inoculation and the functional molecular markers were developed based on the polymorphic SNPs in the CDS region. In addition, a total of four adult plant resistance (APR) loci were identified on wheat chromosome 1BL, 2AS, 2BS and 4AL, respectively. Among these, QYr.hazu-1BL and QYr.hazu-2AS was verified as the known resistance genes Lr46/Yr29/Pm39 and Yr17, respectively. QYr.hazu-2BS was a new APR locus and the closely linked SNP markers were converted into breeder-friendly KASP markers.