Fang Wang,Minghu Zhang,Yanling Hu,Meijuan Gan,Bo Jiang,Ming Hao,Shunzong Ning,Zhongwei Yuan,Xuejiao Chen,Xue Chen,Lianquan Zhang,Bihua Wu,Dengcai Liu,and Lin Huang
Stripe rust caused by P. striiformis Westend. f. sp. tritici (Pst) is one of the most destructive diseases in wheat production. Pyramiding of adult-plant resistance (APR) genes is a promising strategy to increase durability of resistance. The stripe rust resistance genes Yr18, Yr28 and Yr36 encode different protein families which confer partial resistance to a broad array of Pst races. Here, we developed BC3F5 wheat lines representing all possible combinations of Yr18, Yr28 and Yr36 in a genetic background of the highly Pst-susceptible wheat line SY95-71 that is widely used in stripe rust analysis. These lines enabled us to accurately evaluate these genes singly and in combination in a common genetic background. The adult plant resistance experiments were analyzed in the field, where stripe rust epidemics occurred frequently. The field results indicated that these partial resistance genes act additively in enhancing the levels of resistance, and a minimum of two genes combinations can generate adequate stripe rust resistance. The Yr28+Yr36 and Yr18+Yr28+Yr36 combinations also showed adequate resistance at seedling stage, implying APR genes pyramiding can achieve all-stage resistance. Meanwhile, the three genes were simultaneously introduced into elite wheat lines through gene-based marker selection. Elite lines exhibited strong all-stage resistance to stripe rust. This work provides valuable insights and resources for developing durable Pst resistant varieties and for elucidating the regulation mechanism of partial R gene pyramiding.