QTL mapping for adult-plant leaf rust resistance genes in Chinese wheat cultivar Weimai 8

Abstract

The wheat cultivar Weimai 8 is a good source of adult-plant resistance to leaf rust in China. In order to understand the genetic background of the resistance genes, 179 F2:3 families derived from the cross Weimai 8 and Zhengzhou 5389 (susceptible to leaf rust) were used to construct a linkage map. Results showed that there was a major QTL on chromosome 2AS, temporarily named QLr.hbau-2AS, responsible for the resistance. QLr.hbau-2AS from the resistant parent Weimai 8 was between the SSR markers Xcfd36 and Xbarc1138, with an interval length of 2.58 cM. In the 2010-2011, 2011-2012 and 2012-2013 crop seasons, it explained 25.79, 71.55 and 60.72% of the phenotypic variation, respectively. The location of QLr.hbau-2AS was close to the leaf rust resistance gene Lr37. However, they may not be the same since QLr.hbau-2AS has a different virulence test response from Lr37. This study identified two closely linked flanking molecular markers QLr.hbau-2AS and these molecular markers will help marker-assisted selection in breeding resistant cultivars in the future.