Taxonomic Studies On Saprobic Dematiaceous Hyphomycetes From Southwest Of China And Molecular Identification Of Pathogenic Fungal Strains On Dong Jujube Fruit

Saprobic dematiaceous hyphomycetes are anamorphic fungi which are mainly distributed in the humid environment in forest litter, rotten wood and fallen leaves. They play a very important role in degradation of forests and other saprobic substrate, and they are an very important part of forest biological diversity. Three provinces of southwest of China (Yunnan, Guizhou, Hunan) are middle-upriver of Yangtse River, having a unique geographical area complex terrains and notable altitude difference. The area spans several climate zones, covers much tropical and subtropical forest ecosystems. It may contain plenty of dematiaceous hyphomycetes resource. The excellent vegetation makes the fallen dead wood diversiform and enrichment many kinds of known and unknown fungi.This study aimed to survey the population of dematiaceous hyphomycetes from fallen dead wood of Xishuangbanna National Forest Park, Menglun Botanic Garden, wild elephant vally, rain forest valley, Little White Dragon Forest Park in Kunming, Guizhou Anshun Huangguoshu Falls, Kuankuoshui Nature Reserve, Hunan Zhangjiajie Nature Reserve at genus and species level,and layed a foundation for the further study.There are 140 dead wood samples from representative localities were collected. After examination, 32 species belonging to 22 genera were discovered. All genera and species are described and illustrated morphologically. Distribution sites and habitat are also cited.Nine pathogenic fungal strains on jujube in China were identified and analyzed according to the morphological characteristics and ITS sequences. The rDNA ITS regions of these pathogens were amplified by PCR and then sequenced. After analyses of their ITS sequences, a phylogenetic tree was obtained from the program NJ (Neighbor-joining), together with the sequence of related strains which were downloaded from GenBank. The results of morphological observation and molecular detection of these nine strains showed that DH4 and LW5 belong to Alternaria alternata; DJ3 and DJ4 belong to Alternata tenuissima; DH1 and LW4 belong to Phomopsis sp.; DH2 belongs to Phoma glomerata; LW3 belongs to Exserohilum rostratum; DJ5 belongs to Stemphylium solani。...