Genetic analysis of adult plant, quantitative resistance to stripe rust in wheat landrace Wudubaijian in multi-environment trials

Abstract

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases on wheat worldwide. Wudubaijian, a wheat landrace released from Gansu Province in China since 1950, exhibits adult-plant resistance to stripe rust for several decades. To elucidate the genetic basis of stripe rust resistance, Wudubaijian was crossed with the high susceptible cultivar Mingxian 169, and stripe rust tests of both parents and the F2:3 lines were conducted in four environments of Yangling and Tianshui in 2015 and 2016, respectively. The relative area under disease progress curve (rAUDPC) of Mingxian 169/Wudubaijian F2:3 lines showed that the resistance of Wudubaijian was controlled by quantitative trait loci (QTL). Combined with phenotypic data and molecular markers, two stable QTLs were identified in Wudubaijian. QYrwdbj.nwafu-5A with the phenotypic variance of 15.02–40.26% was located between 5AS1–0.40–0.75 and 5AS3–0.75–0.98 of chromosome 5AS, and QYrwdbj.nwafu-2B.1 with the phenotypic variance of 9.54–10.40% was located in the bin C-2BS1–0.53 of chromosome 2BS. Through the location of flanking markers and epistasis analysis, QYrwdbj.nwafu-5A may be a new major QTL that can be used in conjunction with other stripe rust resistance genes (QTLs).