Gnentic Structure Of Blumeria Graminis F.sp.tritici In Anhui Province

Wheat powdery mildew is one of the main diseases of wheat production in Anhui Province.To strengthen the research on the population structure of Blumeria graminis f.sp.tritici.This is beneficial to more systematic understanding of the characteristics of evolution and variation of the disease population,and to provide theoretical basis for scientific disease prevention and control.However,in recent years,the population structure of Blumeria graminis f.sp.tritici in Anhui and the influence of the pathogen population in Tianmu Mountain on the occurrence of wheat powdery mildew in Anhui are still unclear.Therefore,this study collected,isolated and purified multiple samples of wheat powdery mildew in different areas of Anhui Province in 2019,and obtained 325 single spore pile strains.The genetic structure of the pathogen population was analyzed by SSR molecular marker.At the same time,the virulence of 33 Blumeria graminis f.sp.tritici from different geographical locations in Anhui Province in 2019 was monitored by using 42 differential hosts with different resistance genes.The results are as follows:(1)Genetic structure analysis of populations in northern,central and southern Anhui Province showed that the genetic diversity level and genotype diversity of populations in southern Anhui Province were the highest,and showed a decreasing trend from south to north.Dendrogram analysis showed that the populations of Blumeria graminis f.sp.tritici in southern and central Anhui were closely related,while the populations in northern Anhui were relatively distant.The results of Principal Coordinates Analysis showed that the pathogen population in central Anhui province was affected by both southern and northern populations,but the influence of southern population was more significant.(2)In order to further explore the genetic structure relationship among Blumeria graminis f.sp.tritici populations in different areas of Anhui and the influence of the Tianmu mountain pathogen populations on other areas,the tested strains were divided into seven subpopulations: Jixi,Chizhou,Luyang,Changfeng,Huainan,Bengbu and Suzhou.The results showed that the level of genetic diversity of pathogen populations in the south of Luyang,Anhui Province decreased gradually from south to north.Dendrogram results showed that Jixi and Chizhou populations in southern Anhui were closely related to Luyang populations in central Anhui,and Changfeng,Suzhou,Huainan and Bengbu populations in northern Anhui were closely related to each other.Jixi population had a certain influence on other areas of Anhui Province,but the influence on Chizhou population was the largest,followed by Luyang.The level of genotype diversity in Jixi and Chizhou populations was significantly higher than that in other regions.The results showed that the Blumeria graminis f.sp.tritici population in Jixi of Tianmu mountainous area played a very important role in the occurrence and prevalence of wheat powdery mildew disease in Anhui,especially in the southern and central of Anhui Province.(3)The results of virulence identification showed that the resistance genes or combinations Pm XBD、Pm5b、Pm12、Pm13、Pm16、Pm2+MLD、Pm18、Pm21、Pm22、Pm23、Pm35 and Pm46 had good resistance in Anhui Province.Resistance genes or combinations of Pm8、Pm3a、Pm3b、Pm3c、Pm3f、Pm3e、Pm5a、Pm6、Pm7、Pm19and Pm2+Ta had lost resistance in Anhui Province,and should be avoided.The relationship of virulence structure of Blumeria graminis f.sp.tritici population in southern and central Anhui was close,while the distance of population in northern Anhui was farther.