Genome-wide Mapping for Stripe Rust Resistance Loci in Common Wheat Cultivar Qinnong 142.

Abstract

Stripe rust caused by Puccinia striiformis f. sp. tritici threatens worldwide wheat production. Growing resistant cultivars is the best way to control this disease. Chinese wheat cultivar Qinnong 142 (QN142) has a high level of adult-plant resistance to stripe rust. To identify quantitative trait loci (QTLs) related to stripe rust resistance, we developed a recombinant inbred line (RIL) population from a cross between QN142 and susceptible cultivar Avocet S. The parents and 165 F6 RILs were evaluated in terms of their stripe rust infection type and disease severity in replicated field tests with six site-year environments. The parents and RILs were genotyped with single-nucleotide polymorphism (SNP) markers. Four stable QTLs were identified in QN142 and mapped to chromosome arms 1BL, 2AL, 2BL, and 6BS. The 1BL QTL was probably the known resistance gene Yr29, the 2BL QTL was in a resistance gene-rich region, and the 2AL and 6BS QTLs might be new. Kompetitive allele specific polymerase chain reaction markers developed from the SNP markers flanking these QTLs were highly polymorphic in a panel of 150 wheat cultivars and breeding lines. These markers could be used in marker-assisted selection for incorporating the stripe rust resistance QTL into new wheat cultivars.