RESEARCH ARTICLE Mapping a Large Number of QTL for Durable Resistance to Stripe Rust in Winter Wheat Druchamp Using SSR and SNP Markers

Winter wheat Druchamp has both high-temperature adult-plant (HTAP) resistance and all-stage resistance to stripe rust caused by Puccinia striiformisf. sp. tritici (Pst). The HTAP re-sistance in Druchamp is durable as the variety has been resistant in adult-plant stage since it was introduced from France to the United States in late 1940s. To map the quantitative trait loci (QTL) for stripe rust resistance, an F8 recombinant inbred line (RIL) population from cross Druchamp × Michigan Amber was phenotyped for stripe rust response in multiple years in fields under natural infection and with selected Pst races under controlled green-house conditions, and genotyped with simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers. Composite interval mapping (CIM) identified eight HTAP re-sistance QTL and three all-stage resistance QTL. Among the eight HTAP resistance QTL, QYrdr.wgp-1BL.2 (explaining 2.36-31.04 % variation), QYrdr.wgp-2BL (2.81–15.65%), QYrdr.wgp-5AL(2.27–17.22%) andQYrdr.wgp-5BL.2 (2.42–15.13%) were significant in all tests; andQYrdr.wgp-1BL.1 (1.94–10.19%),QYrdr.wgp-1DS (2.04–27.24%),QYrdr.wgp-3AL(1.78–13.85%) andQYrdr.wgp-6BL.2 (1.69–33.71%) were significant in some of th