Mapping of a stripe rust resistance gene YrYN1813 in wheat

Abstract Wheat stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a global threat to wheat production. Pst race CYR34 is now widely virulent and prevalent in China following its identification in 2009. Here, we report the mapping and candidate gene analysis of a stripe rust resistance gene in a Chinese winter wheat breeding line YN1813. Ten F1, 719 F2 plants, and 306 F7:8 recombinant inbred lines (RILs) derived from cross YN1813/Chinese Spring were inoculated with Pst race CYR34 at the seedling stage in a greenhouse. Monogenic segregation for seedling stripe rust response was observed among the RILs and F2 population, and the resistance locus was designated YrYN1813. RILs were genotyped by the wheat 55K SNP array. By linkage analysis, YrYN1813 was mapped to a 0.34 cM, 2.4 Mb physical interval (717.9–720.3 Mb) spanned by AX-111630305 and AX-109458466. Following, YrYN1813 was narrowed to an approximately 254 kb (717.890–718.144 Mb) physical interval between the marker AX-111630305 and AX-108820558 by haplotype analysis, including three putative disease resistance genes based on IWGSC RefSeq v1.0. Through gene expression level analysis and sequence alignments of resistant and susceptible parents, we predicted TraesCS7B01G460500 to be a candidate gene for map-based cloning of YrYN1813. Stripe rust response data and molecular marker analysis revealed that YrYN1813 was differed from the other Yr genes on chromosome arm 7BL. YrYN1813-linked marker AQP_ AX-108877192 was polymorphic among 81.7% of 720 wheat lines and can be used for marker-assisted selection for improved stripe rust resistance in wheat.