Abstract

In order to clarify the genetic characteristics of resistance to stripe rust in new wheat germplasm N07168 and lay the preliminary foundation for the subsequent QTL fine mapping and the cloning of resistance genes, this experiment used N07168 as the male parent, crossed with the susceptible wheat cultivar Xinong979, to obtain the F2 and F2:3 segregating populations. The mixed inheritance model analysis method based on plant quantitative traits was applied to analyze five basic populations (P1, P2, F1, F2 and F2:3). The results showed that the optimal inheritance model for stripe rust resistance at the adult plant stage in new wheat germplasm N07168 was D-3 model, which is a mixed inheritance model of "one pair of major genes with completely dominant effect plus polygenes with additive-dominant effect". The heritability of major resistance genes was 74.88 and 73.05% in the F2 and F2:3 populations, respectively. The polygenes’ heritability was 3.92 and 3.49%, respectively, with an additive-dominant effect. The proportions of the environmental variance to the phenotypic variance were 21.2 and 23.06%, respectively, indicating that environmental effects also had an influence on the resistance expression of the major gene. Finally, using a set of nulli-tetrasomic lines of “Chinese Spring”, we confirmed that this pair of completely dominant major genes was located on chromosome 1B.