Genetic Analysis and Molecular Mapping of Leaf Rust Resistance Genes in the Wheat Line 5R618

Wang J., Shi L., Zhu L., Li X., Liu D. (2014): Genetic analysis and molecular mapping of leaf rust resistance genes in the wheat line 5R618. Czech J. Genet. Plant Breed., 50: 262–267. The wheat (Triticum aestivum L.) line 5R618, bred at the China Agricultural University, is resistant in the seedling stage to the majority of the current Chinese pathotypes of wheat leaf rust (Puccinia triticina). To identify and map the leaf rust resistance gene in the 5R618 line, F2 plants and F2:3 families from a cross between 5R618 and Zhengzhou5389 (susceptible) were inoculated in the greenhouse with the Chinese P. triticina pathotype THJP. Results from the F2 and F2:3 populations indicate that a single dominant gene, temporarily designated Lr5R, conferred resistance. Using the molecular marker method, Lr5R was located on the 3DL chromosome. It was closely linked to the markers Xbarc71 and OPJ-09 with genetic distances of 0.9 cM and 1.0 cM, respectively. At present only one designated gene (Lr24) is located on the 3DL chromosome. The genetic distance between Lr5R and Lr24 confirms that Lr5R is a new leaf rust resistance gene.