Molecular Mapping for Leaf Rust Resistance Genes in Wheat Line Tian 95HF2

The wheat (Triticum aestivum L.) line Tian 95HF2 shows low infection to most of current Chinese pathotypes of Puccinia triticina at seedling stage. With the objective of identifying leaf rust resistance genes in Tian 95HF2, F1 and F2 plants from a cross between resistant line Tian 95HF2 and susceptible line Zhengzhou 5389 were inoculated with pathotypes FHTT and PHTS in the greenhouse. The infection types were scored 15 d after inoculation and molecular markers were used for mapping the resistance genes. When inoculated with pathotype FHTT, only one resistance gene was detected. After screening 1274 primer pairs in the parents and the resistant and susceptible bulks, the resistance gene was located between a sequence tag site for Lr1 (WR003) and a simple sequence repeat locus Xwmc443 on chromosome arm 5DL. The genetic distances to WR003 and Xwmc443 were 2.9 cM and 3.1 cM, respectively. This resistance gene was likely to be Lr1. The segregation of infection type showed that there were 2 resistance genes in Tian 95HF2. One was inferred as Lr1, and the other was likely to be LrZH84, which is located on chromosome 1BL.

摘 要苗期基因推导表明, 小麦品系天95HF2高抗中国目前多数叶锈菌生理小种。为了确定这一品系所携带的抗病基因, 以天95HF2和感病小麦品种郑州5389杂交, 获得F1和F2代群体, 用叶锈菌小种FHTT和PHTS分别对双亲及其杂交后代进行叶锈抗性鉴定并进行分子标记分析。结果表明, 用叶锈菌小种FHTT接种F2代群体时呈现1对显性基因的抗感分离比例, 经过亲本和抗感池间标记筛选以及F2代群体的标记检测, Lr1的STS标记WR003和位于5DL的SSR标记wmc443与该抗病基因连锁, 遗传距离分别为2.9 cM和3.1 cM, 根据抗性特点和染色体位置推断该基因可能为Lr1。用叶锈菌小种PHTS接种F2代群体时呈现2对基因的抗感分离, 分子标记分析结果表明, 其中一个基因为Lr1, 另一个基因可能为LrZH84。