关键词: 小麦, 秆锈病, SSR, Sr22, 分子标记

Abstract:

【Objective】 The microsatellite markers closely linked to Sr22 were screened to be used in marker-assisted selection for breeding and gene detection (diagnose) for resistant germplasm and varieties. 【Method】 A population of F2 plants was generated from one F1 plant derived from a cross between susceptible wheat cultivar McN701 and wheat monogenic line SWSr22, and seedlings of parents and F2 plants were inoculated for genetic analysis. In addition, parental DNA and bulked segregant analysis (BSA) were used to screen for polymorphism with 73 SSR markers that covered the chromosome 7A of wheat. The markers showing DNA polymorphism were validated by F2 population and F2:3 family of SWSr22×McN701. 【Result】 The resistance to 21C3CTH must be the gene contained in monogenic line SWSr22 and was controlled by a single dominance. Two co-dominant markers Xwmc790 and Xwmc633 were identified and mapped on the distant side of centromere, with distances of 2.8 cM and 10.8 cM, respectively. 【Conclusion】 The two markers were tightly linked with Sr22 and could be used in marker-assisted selection of Sr22 for breeding.

Key words: wheat, stem rust, SSR, Sr22, molecular marker