Identification Of Resistant Genes To Wheat Leaf Rust In Pavon76

Pavon76 possessing permanent resistance, it has kept on good resistance to wheat leaf rust since it was planted in Mexico. Pavon76 was used as parents to cultivate some resistant diseases cultivars in China since 1970s. Presently, it has only been definited that Pavon76 possesses wheat leaf rust resistance gene Lr46. However, it is undefinited that whether it possesses other wheat leaf rust resistance genes. So it is important for the reasonable using of resistant cultivars to know about the constitutes of resistant genes and genetic characters of wheat cultivar and germplasm.The genetic analysis of resistance, gene postulation, molecular assisted selection, pedigree analysis and AFLP analysis of Pavon76 to wheat leaf rust were conducted in this paper.Through seedling infection types derived from the interaction of 19 test strains of Puccinia triticina and 46 near-isogenic lines with know Lr genes and Pavon76, the genes Lr1, Lr3, Lr10, Lr14a, and unknown genes LrB for leaf rust resistance in seedling stage of Pavon76 were postulated. Through adult infection types derived from the interaction of 9 test strains of Puccinia triticina and 8 near-isogenic lines with know Lr genes and Pavon76, the genes Lr13, Lr14b, Lr34 and Lr35 for leaf rust resistance in adult stage of Pavon76 were postulated.The results of seedling resistance of F₂, F₃ generations from Pavon76/Thatcher and parents to BBDL strain of Puccinia triticina indicates that there were at least two wheat leaf rust resistance genes to Puccinia triticina in seedling plants.The results of adult resistance of F₂, F₃ generations from Pavon76/Thatcher and parents to DDQS strain of Puccinia triticina indicates that there were at least two wheat leaf rust resistance genes to Puccinia triticina in adult plants.Through stable molecular markers Lr9, Lr10 Lr19, Lr20, Lr24, Lr35 and Lr37, the results of molecular assisted selection showed that Pavon76 possesses Lr 10, not Lr9, Lr19, Lr20, Lr24, Lr35 and Lr3 7 wheat leaf rust resistance genes.In order to get relatively specific bands between Pavon76 and Lrl, Lr3, Lr13, Lr14a, Lr14b, Lr34 and LrB, 304 pairs primers screened for AFLP analysis. 17 pairs of them amplified 29 specific bands between Pavon76 and Lrl, Pavon76 and Lrl3, Pavon76 and Lr14a, Pavon76 and LrB, which indicates that Pavon76 probably possesses Lr1, Lr13, Lrl4a, LrB, not Lr3, Lr14b, Lr34 wheat leaf rust resistance genes.Through pedigree analysis, Pavon76 probably possesses Lr1, Lr10, Lr13, Lr14a, Lr23, Lr34 and Lr46.To sum up, Pavon76 possesses Lr10, Lr13 and Lr46;probably LrB;Lr1 or Lr14a.