Molecular Mapping Of Wheat Leaf Rust Resistance Gene In Henong6251and Henong5290at Seedling Stage

Wheat leaf rust, caused by Puccinia triticina, is one important worldwide disease,always can result in severely reduce the yeild of wheat. In recent years, climateconditions become more appropriate for occurrence and spread of wheat leaf rustspecially, so the control of the disease has become essential. The most cost-effectivemethod is utilization of resistant varieties. However, most of the known genes conferredphysiological specifically resistance to P. triticina. The wheat cultivars always lost theirresistance to leaf rust when virulent races emerge or increase. Only Lr9、Lr19、Lr24、Lr34、Lr38、Lr42and Lr46etc provied strong resistance to isolations of P. triticina inChina till now. However, these resistance genes are difficult to control the spread of thewheat leaf rust and easy to be overcome by the new leaf rust races. Therefore, constantlydiscovering new resistance genes and developing new disease-resistant varieties aresignificance to the prevention and treatment of wheat leaf rust disease.Henong6251and Henong5290are new varieties of wheat developed byAgricultural University of Hebei. Preliminary research showed that they all contributedhigher disease resistance level to P. triticina. And genetic analysis of leaf rust resistanceshowed that the resistance of Henong5290is controlled by a dominant resistance genewhich is different from the known wheat leaf rust resistance genes. In this study, resistantparents Henong6251, Henong5290, susceptible parent Thatcher and their F1, F2population were employed, and BSA and SSR technique were used to mapping the leafrust resistance genes in the two cultivars. The results are as follows.1. Molecular marker-assisted identification results show Henong6251contains leafrust resistance gene Lr26and LrZH84, and may contain Lr2c and Lr17a. Henong5290may contain Lr14a, Lr52and Lr68.2.Henong6251, Thatcher, and their Fl, F2populations and F3families were tested forwheat leaf rust resistance with Chinese P. triticina pathotype PBGP in greenhouse. Theresults showed that the leaf rust resistance in Henong6251was controlled by onedominant resistance gene, temporarily designated as LrH6.3. A total of1504pairs of SSR primers were used to test Henong6251and theirresistant and susceptible bulks of F2and F3populations for mapping the leaf rust resistance gene. Results indicated that Henong6251carries a single dominant resistancegene LrH6to PBGP, preliminary located on chromosome1B. The resistance gene LrH6was linked to the three known SSR loci（wmc419,wms582and barc120）on the1BL withgenetic distance ranging21.6cM,25.8cM and27.9cM respectively.4. The pedigree of Henong6251showed that it may contain resistance gene LrZH84in Zhou8425B with4.9cM to wms582. But the genetic distance between the wms582andthe resistance genes in Henong6251is25.8cM. It suggests that the gene confersresistant to PBGP in the variety is not LrZH84.5. SSR molecular markers and BSA were used to test the F2populations for mappingthe leaf rust resistance gene in Henong5290. Linkage analysis indicated that Henong5290carries a single dominant resistance gene LrH5to FCGT and preliminary located onchromosome5BL. The resistance gene LrH5was linked to the SSR loci wmc452on the5BL with genetic distance5.9cM.