Species Of The Genus Pythium And Their Ecological Distribution In The North Of Guangxi

Total 341 strains of the genus Pythium were isolated from 413 soil materials collected from the north of Guangxi Zhuang Autonomous Region of China. Sixteen species were identified. Among them, Pythium graminicola Subramanian and P. indigoferae Butler were new records in Guangxi. P. aphanidermatum (Edson) Fitzpatrick was dominant. The other 13 species were Pythium acanthicum Drechsler, P. aquatile Hohnk, P. dissotocum Drechsler, P. elongatum Matthews, P. amasculinum Yu, P. pulchrum Minden, P. kunmingense Yu, P. nanningense C.Y.Lai & G.Q.Yuan, P. acanthophoron Sideris, P. ultimum Trow, and P.falciforme G.Q.Yuan & C.Y.Lai. In addition, the ecological distribution of these species in this region was also investigated in this paper. It indicated that the species composition of the genus Pythium was different in different sampling sites. The acidity of soil affected on the community of the genus Pythium slightly, as the same as the temperature of soil. The isolation frequency of Pythium strains changed greatly in different month. And then, it was higher in winter and spring than that in high temperature season. Pythium strains were most abundant in yellow soil whose altitude ranged from 801 to 1 000 metres. The isolates were inclined to decrease when the altitude ascended or descended. As a conclusion, Every ecological factor impacted on the distribution of Pythium species differently. And all the factors took effect on the distribution synthetically.