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.