Resistance performance of wheat stripe rust resistance gene Yr41 and its effect on yield parameters in F2 populations under field conditions

Yr41 is an all-stage resistance gene against wheat stripe rust. Previous greenhouse tests showed that Yr41 had strong resistance to races CYR31, CYR32, SY11-4, V26, and so on. To evaluate the contribution of Yr41 in practical wheat production, three F-2 populations derived from disease-resistant parents, AIMS and AIM6, which carry Yr41, and a susceptible parent L661, which lacks Yr41 (i.e., AIM5/L661, AIM6/L661, and L661/AIMS) were employed to investigate resistance responses and yield components under field conditions. Therefore, the molecular marker BE446068, which is closely linked to Yr41, within 0.19 cM, was also employed to identify the F-2 plant genotypes. A chi(2) test showed that infection type exhibited a significantly skewed distribution in the three genotypes of homogenous RR, heterogeneous Rr, and homogenous rr plants but not in the heterogeneous Rr plants derived from AIM5/L661 at the P = 0.05 level, indicating that Yr41 was effective against stripe rust. Multiple comparison analysis of yield parameters among various genotypes showed that yield parameter TGW exhibited significant differences among the three genotypes of all cross combinations at the P = 0.05 level, and there was no obvious difference in PEP among them, which could be explained by the onset and development of stripe rust. Multiple comparison results suggested that Yr41 could protect yields by preventing decreases in yield parameters, especially TGW, with additive and partial dominant effects. Yr41 will play an important role in the improvement of wheat resistance to stripe rust and wheat production practices and provide a new strategy to evaluate disease resistance under field conditions.