Resistance To Powdery Mildew. Common Wheat Brock A New Gene Aflp Markers

Powdery mildew, caused by Erysiphe graminis DC.f.sp.tritici, is one of the most serious diseases of common wheat in China and in many other countries of the world. Most of the powdery mildew resistance genes have already been overcome by new virulent E. graminis strains owing to the single genetic resistant source and the repeatable use of it. Discovery and utilization of novel resistance genes, pyramiding of existing ones, and breeding for resistant cultivars have been proved effective ways to control the disease.In this study, a total of 225 primer combinations were screened to identify polymorphisms between the resistant parent Brock, susceptible parent Jing 411 and the NILs of Jing411 using AFLP technique.The main results are as following:1. Response type of plants to powdery mildewBrock, Line 015, Jing411 and 106 individuals which were obtained from hybrid F₂ population (Brock XJing411), and their cross, backcross progenies (Line Brock/015//Jing411⁷) were artificially inoculated with the race NO.15. Cultivated wheat Brock was immune to the race NO.15. Common wheat cultivar Jing411 and Line 015 were highly susceptible to that powdery mildew pathogen. Brock/015//Jing411⁷ was highly resistant to powdery mildew. F₁ (Brock×Jing411) was resistant to powdery mildew. In the test of 106 F₂ plants, 79 individuals were resistant and 27 individuals were susceptible, which showed the expected Mendelian ratio of 3: 1.2. Identification of AFLP markers linked to the powdery mildew resistance gene in BrockA total of 225 AFLP primer combinations were screened to identify polymorphism between the resistant parent Brock, susceptible parent Jing411 and the resistant Line Brock/015//Jing4 11⁷, using AFLP technique. All the AFLP primer combinations could amplify clear bands. Among them, only 28 primer combinations could generate reproducible polymorphic amplification patterns between Brock,...