粗山羊草Y192中抗叶锈基因LrY192的SSR定位

 【目的】在粗山羊草(Aegilops tauschii)中寻找新的抗叶锈病基因，为抗病育种提供新种质。【方法】本研究对抗小麦叶锈病的粗山羊草Y192和感小麦叶锈病的Y2272进行杂交，通过F2代抗叶锈性分离情况确定可能含有的抗叶锈基因数量，应用分离群体分组法（bulked segregation analysis，BSA）筛选D染色体上与抗叶锈性相关的SSR标记，用MapChart软件构建遗传连锁图谱。利用分子辅助鉴定和抗叶锈表型分析推测Y192可能含有的抗叶锈基因。【结果】在接菌04-5-192(THNT)的杂交后代中F1代表现抗病，F2代表现3:1的抗感分离，表明该基因为一个显性抗病基因，将该抗病基因暂命名为LrY192。筛选到的3个SSR标记Wmc245、Xgwm296和Xgwm261与该基因的遗传距离分别为4.1、18.9和26.2 cM。根据连锁标记在小麦微卫星图谱的位置，LrY192被定位在2D染色体上。【结论】综合分析基因所在的染色体位置及抗病特性，认为LrY192是一个新的抗小麦叶锈基因，获得的SSR标记Wmc245可用于分子辅助选择。

SSR Mapping of Leaf Rust Resistance Gene LrY192 in Aegilops tauschii Y192

【Objective】 The objective of this study is to find new leaf rust resistance gene in Aegilops tauschii, and provide valuable information and germplasm for wheat leaf rust resistance breeding.【Method】 Hybridization between Ae. tauschii Y192 (resistant) and Ae. tauschii Y2272 (susceptible) was carried out and the resistance of F2 population was evaluated by inoculated Puccinia triticina for investigating the resistance genes in Y192. Bulk segregation analysis and microsatellite markers on chromosome D were used to tag the resistance gene in Y192. The genetic distance was calculated by MapChart software. Gene postulation and MAS were also used to identify the resistance genes in Y192. 【Result】 F1 population derived from the crossing Y192 and Y2272 were resistant, and the ratio of resistance/susceptible was 3:1 in F2 generation. This indicated that a dominant wheat leaf rust resistance gene was presented in Y192. The gene was temporarily designated as LrY192.Three microsatellite markers Wmc245, Xgwm296 and Xgwm261 were acquired from SSR markers and linked to LrY192 with genetic distance of 4.1, 18.9, and 26.2 cM, respectively. According to the locations of the linked markers, the resistance gene was located on chromosome 2D. 【Conclusion】 Based on the chromosomal location and the resistance pattern of the gene, it is concluded that LrY192 is a novel leaf rust resistance gene, and could be selected by Wmc245.