White Powder Of Gansu Province, Bacteria Class, Distribution And Ecological Flora (a)

The results of the preliminary studies showed: the powdery mildews fungi were widespread and common in all parts of Gansu province, more than 360 collections have been studied in which teleomorphic taxa have been described, 66 species belonging to 12 genera parasited on 133 host plants are known. All the collections were studied very critically with the help of upto date literature and the genera and species were confirmed according to the key ~provided by Zheng Ruyong et. al.(l 987) and Braufr U.. In the listed species one flew species taxa was proposed: Microsphaera helwingiana S.R. Wang sp. nov., it parasited on leaves of Helwingiajaponica (Thunb.) Dietr., and 4 new records of China: Erysiphe ulmariae Desm., Sphaerotheca delphini! (Karst.) Blumer, Sph. spiraeae Sawada and Sph. verbenae Savul. & Negru. Species first reported in Gansu province were listed as follows: Erysiphe epin3edii (Tai) Zheng & Chen var. epimedii, E. galii Blum., E. lycopsidis Zheng & Chen, E. paeoniae Zheng & Chen, E. rabdosiae Zheng & Chen, Leveillula scrophulariacearuni Go] ov., Microsphaera berberidicola Tai, M hedwigii L~?.?P kvllacilnia berberidisYéˆ'la, Podosphaera tridactyla(Wallr.) De Bary , Sawadaia boniiensis Zheng & Chen, Sphaerotheca astragali June11 var. astragali. Sph. balsam mae (Wallr.) Kari, Sph. fugax Penz. & Sacc., Trichocladia asiragali(DC. )Neger. Tr. swainsoniae Yu and Lai. Uncinula actinidiae Miyabe ex Jaczewski. U betulae Homma. U kenjiana Homma, U necator (Schwein.) Burr. and U regularis Zheng & Chen. The powdery mildews?ecological distribution of Xinglongshan Natural Protection Area showed: this kind pathogens were common at this area. Diversity of the host plants affected Erysiphales diversity directly, it also has a close relations with relative humidity (RH) of the environment as well, the powdery tnildews were fewer and have lighter severity at area of higher altitude and RI-I by contrasted to the low altitude and RI-I area. Most infected host plants had a well- distribution or distributed as patches. In this area, Sphaerotheca and Erysiphe had a wide niche breadth. ~ .000, BE=O.974. the result indicated Sphaerotheca and Erysiphe can use the environmental resources more effectively and could fit nvironmental conditions more easily.