Assessment of stripe rust resistance at adult plant stage and molecular detection of important Yr genes of wheat commercial cultivars in Yunnan

【Objective】This paper was designed to analyze the resistance to stripe rust and distribution of important Yr genes in major wheat commercial cultivars inYunnan，so as to provide information for resistance breeding and cultivars rational deployment.【Method】Using natural identification in the field，this study carried out the resistance assessment at adult plant stage to stripe rust of 73 wheat commercial cultivars and Yr near-isogenic lines for detection，at two sites of wheat stripe rust in Songming County of Kunming City and Shizong County of Qujing City from 2019 to 2022 for 3 wheat growing seasons continuously. And the distribution of the important stripe rust resistance genes such as Yr5，Yr9，Yr10， Yr15，Yr17，Yr18 and Yr26 in these cultivars were detected by molecular marker detection.【Result】Among the 73 tested cultivars，Fengmai 34 showed highly resistant，accounted for 1.4%. Ten cultivars Moba 66，Yunmai 34，Fengmai 39， Yunmai 56， Yunmai 68， Yunmai 110， Yunmai 112， Dianmai 7， Yunmai 80 and Yunmai 83 showed slow rusting，accounted for 13.7%. The other 62 cultivars showed susceptible，accounted for 84.9%. None of cultivars carried Yr5 and Yr15 genes among the 73 tested cultivars； 42 cultivars carried Yr9 gene， accounted for 57.5%； 17 cultivars carried Yr17 gene， accounted for 23.3%；11 cultivars carried Yr18 gene，accounted for 15.1%；7 cultivars carried Yr26 gene，accounted for 9.6%； 5 cultivars carried Yr10 gene，accounted for 6.8%.【Conclusion】The resistance level to stripe rust of wheat commercial cultivars in Yunnan is relatively low. A few cultivars that show slow rusting and are used currently in wheat production， such as Yunmai 56，Yunmai 68，Yunmai 110，Yunmai 112，Dianmai 7，Yunmai 80 and Yunmai 83，are suggested to be enlarged application. Five resistance genes against stripe rust（Yr9，Yr17，Yr18，Yr26，and Yr10）are contained in Yunnan commercial cultivars，they are ineffective now and should be reduced their application or combined with other effective genes. It is suggested to introduce the current effective genes Yr5 and Yr15 into commercial cultivars to enhance its resistance to stripe rust in Yunnan.