Study On Population Genetic Structure Of Blumeria Graminis F.sp.tritici In Sichuan

Wheat powdery mildew (Blumeria graminis f.sp.tritici) was an important worldwide disease of cereal crops, it was also a serious biological disasters which have a long-term impact on the safety of Chinese wheat production. Using the resistant varieties was the most economical and effective measure to control the disease, and monitoring the powdery mildew dynamics of races timely and accurately was the foundation in controlling wheat powdery mildew epidemiology. Get known the structure of pathogen populations and their distribution in the over-wintering and over-summering areas of powdery mildew step by step, it would have a great significance in breeding for disease resistance and guiding the rational varieties distribution.313 samples of B. graminis f.sp.tritici were collected from Sichuan Province,168 strains were obtained by purification and storage. Physiologic race and population virulence of B.graminis f.sp.tritici were tested on detached wheat leaves.28 physiologic races were obtained, Race 317 was dominant race with frequency of 11.31%.The frequency of weakly virulent race, moderately virulent race and strongly virulent race is 4.76%,4.17% and 91.07%, respectively. Isolates V13 and V2+6 showed the virulence frequency below 20%,while other isolates among 20%-60%. The above results indicated Pm13 and Pm2+6(resistance genes) provided applicable value in breeding.20 isolates were tested in RAPD analysis.120 loci were obtained through ampliation with 9 primers, polymorphic frequence with 67 polymorphic loci was 55.83%.Loci focused on 100-1500bp. RAPD analysis showed similarity but also difference among the isolates,which showed the genetic diversity in the population of B. graminis f.sp.tritici.Clustering analysis showed that the same filed collected together.20 isolated were tested with the genetic distance from 0.0613-0.6325.Clustering analysis showed that the same physiologic race collected un-together. Compared with traditional morphological and molecular marker classification, there was a little dissimilar. The SPSS statistics software and the NTSYS-PC 2.1 software statistics consistent with the results of statistical clustering, therefore in analysis of B. graminis f.sp.tritici RAPD results, two kinds of methods are all viable.