Molecular Detection Of Stripe Rust Resistant Genes In115Winter Wheat Varieties From The Shanxi Wheat Region

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is an airborne disease ofwheat worldwide. China is the largest region of epidemic wheat stripe rust in the world, inwhich Shaanxi Province is one of the frequent epidemic region and the area for pathogeninteraction. Therefore, figuring out the resistant level of main and backup cultivars of this areaand the resistance genes conditions of the cultivars, could provide technically andtheoretically guidance for distribution of resistant cultivars, disease resistance breeding andcomprehensive control of wheat stripe rust.This study collected115wheat cultivars, including61main cultivars,42regional testcultivars and12breeding lines, in Shaanxi Province in2012and tested all of these cultivarswith CYR32and V26. Besides, effective molecular markers of Yr5, Yr9(1B/1R), Yr10, Yr18and Yr26were used to detect the distribution of resistance genes in the115cultivars. Basedon the genetic pedigree of cultivars, resistance test and molecular detection, results are asfollows:1Seedling test showed that among all115tested cultivars,63of them (54.78%) wereresistant to CYR32,84(73.04%) were resistant to V26and53of the cultivars (46.09%) wereresistant to both CYR32and V26. Specifically, there were35cultivars resistant to CYR32and43to V26, accounting for57.38%and70.49%among the main cultivars tested,respectively. In the42regional test cultivars,23(54.76%) were resistant to CYR32and30ofthem (71.43%) to V26. As for the12breeding lines, there were5(41.67%) of them resistantto CYR32and11(91.67) to V26. It illustrated that resistant level of main and backup cultivarsto stripe rust CYR32and V26were relatively high.2Molecular detection showed that none of the tested cultivar contain Yr10and that42cultivars (36.52%) contain Yr9(1B/1R). There were only3,3, and2cultivars contain Yr5,Yr18and Yr26, with percentages of2.61%,2.61%and1.74%, separately. It showed that distribution frequency of Yr5, Yr10, Yr18and Yr26were much too low and all these genesexcept Yr9were still useable for disease resistance breeding in Shaanxi Province.