Taxonomy And Flora Of Powdery Mildews (Erysiphaceae) In Jilin Province

Powdery mildews are obligate parasites. The typical symptom of powdery mildew disease is the formation of white powdery spots on the surface of plant, which are composted of mycelia, conidia and conidiophore. Cleistothecia form as the disease progresses. Powdery mildew distributes all over the world and can infect a wide range of angiosperms and cause serious destruction on vegetables, crops, fruit trees, grass and flowers. Investigation on flora of powdery mildew fungi will provide not only samples for biological and phylogenetic research, but also the information of disease control and biodiversity protection.A total of eight genera, forty-seven species and nine varieties of telemorph were identified from622collections and214herbarium samples using the traditional morphological method based on the new taxonomy system. Among them, there is one new record species in China, two new record species to Northeast of China, three new record species to Jilin province. The host plants included45families,140genera,245species.The preliminary flora analysis of powdery mildews showed that Erysiphe is the dominant species and accounted for49.3%of the total number of powdery mildew in Jilin Province. Podosphaera,followed and accounted for25.35%, Golovinomyces is11.27%, Phyllactinia is5.63%, Neoerysiphe and Swmadaea is2.82%respectively, Blumeria and Arthrochadiella is1.41%respectively. Those powdery mildews species were grouped into seven distribution types as North Temperate elements (25.35%), Eastern Asian-North American elements (2.82%), Eastern Asian elements (29.85%), Old World Temperate elements (11.27.%), Cosmopolitan (19.72%), Temperate Asian elements (1.41%), and endemic to China (9.86%). The species and genera distributed unevenly among9prefecture-level cities. In Baicheng and Songyuan, the number of species is much less than other cities. Among the host plants of the powdery mildew, Asteraceae was the main host in Jilin Province accounting for23.87%, and followed by Legaminosae accounting for10.57%, Rosaceae, accounting for9.97%, Lamiaceae5.14%, Salicaceae4.53%, Umbelliferae4.23%, Cucurbitaceae, Rananculaceae and Polygonaceae3.93%repectively, other families accounting for30.01%. Among forty-nine host families, the top four families with the most number of powdery mildew are Rosaceae (4genra,11species, including variety and not including anamorph species. Same in the following.), Fabaceae (3genra,10species), Lamiaceae (3genera,5species), Asteraceae (2genra,5species). The total number of species on those four families was twenty-one and account for29.59%of the total number in Jilin Province. There are three species on Euphorbiaceae and Salicaceae respectively, two species on Fabaceae and other9families, one species on Menispermaceaeand other twenty families respectively. Only anamorph was found on twelve host families. The powdery mildews fungi in Jilin Province had distinct characteristics of those in Temperate Zone, and was closed to those in Inner Mongolia, Liaoning, and Heilongjiang in Northeast of China, but far to those in warm temperate zone and subtropical zone.