小麦品系5R618抗叶锈基因的初步定位

5R618是高抗叶锈病小麦品系。为了确定该品系所携带的抗叶锈基因,以5R618与感病小麦品种郑州5389杂交获得F1,自交获得F2分离群体以及F2∶3家系,用叶锈菌生理小种THJP对亲本、F2分离群体以及F2∶3家系进行叶锈抗性鉴定,然后进行分子标记分析。结果显示,5R618对生理小种THJP的抗病性由1对显性基因控制,该基因暂命名为Lr5R。经过亲本和抗感池间分子标记筛选以及F2∶3家系的标记检测,Lr5R定位于染色体3DL上,barc71和STS24-16是Lr5R最近的2个标记,遗传距离分别为0.9 c M和2.1 c M。

The Study of Leaf Rust Resistance Gene in Wheat Line 5R618

The wheat (Triticum aestivum L.) line 5R618 appears in low infection to most of Chinese current pathotypes of Puccinia triticina at seedling stage. In order to ascertain the resistance genes in 5R618, F2 segregating population and F2: 3 families originating from a cross between 5R618 and Zhengzhou 5389 (susceptible to leaf rust) were inoculated with pathotype THJP in greenhouse. The infection types were investigated 15 d after inoculation and molecular markers were also used for mapping the resistance genes. Results indicated that there was a single dominant resistance gene in 5R618, temporarily designated Lr5R. By using molecular marker Lr5R was located on chromosome 3DL and closely linked to barc71 and STS24-16, with genetic distances of 0.9 cM and 2.1 cM respectively. Based on the SSR markers, it can be concluded that Lr5R is likely to be a new leaf rust resistance gene.