Study On The Diversity Of Dematiaceous Hyphomycetes In Tianhetan

The group of dematiaceous hyphomycetes contain those fungal which can perform all or part of their life cycle in soil.The color of the conidum,conidiophores or hypha are dark to black.China contains different kinds of terrain,climate and vegetation,which already accumulated varied soil substrates suitable for fungal growth and inclouding a wide variety of dematiaceous hyphomycetes resources.The Tianhetan is belong to Guiyang city,which contains abundant vegetation types.Such as farmland,forests,and river valleys.Thus the type of soil is also diverse.In this study,we mainly investigated the soil dematiaceous hyphomycetes resources in Tianhetan section.In order to further explore this kind of fungal resources in China and provide the basis for the subsequent research and development of this group.We collected a total of 210 mixed soil samples from Tianhetan and the farmland surrounded it.And 312 strains were isolated from soil by dilution plate method.Among them,51 strains were identified dematiaceous hyphomycetes,concluding 19 genera,24 species based on morphologic and phylogenetic characters.2 genera belong to Stilbellales,15 genera belong to Hyphomyceteles and 2 genera belong to Tuberculariales.One of the new species is Paramyrothecium hydei(published);two China's new records are Albifimbria terrestris and A.verrucaria(published);and two unidentified species.All of the specimens were preserved in department of Plant Pathology,Agricultural College,Guizhou University(HGUP).We made a taxonomic key for 15 genus which blongs to Hyphomyceteles.And made the detail morphological descriptions for all species and DNA extraction and alignment of ITS sequences were made.We combined four genes of cmdA,ITS,rpb2,and tub2 to identify these strains.A new species and two new Chinese records were analyzed for their molecular data using Maximum Likelihood and Maximum Parsimony,respectively.A multi-gene phylogenetic tree was constructed to systematically analyze the discriminating degree and the degree of confidence(support rate)of the new species.Thus,it can determined the classification status.