Morphological And Molecular Phylogenetic Analysis Of Five Genera Of Soil Dematiaceous Hyphomycetes In China

Soil is the basal substrate for all terrestrial ecosystems, and soil fungi play a very important role in the soil micro-ecological balance. Soil fungi are those which have part or whole life cycle either in or directly associated with soil environment. Fungi exhibit quite abundant diversity. The species of Fungi Imperfecti are the most abundant in the soil, of which dematiaceous Hyphomycetes account for more than one half. This research focused on the classification of dematiaceous Hyphomycetes, through analysis of morphological characters and molecular data, a systematic study was carried out in five doubtble genera.In the classification of dematiaceous Hyphomycetes, there are a lot of controversial issues because of different classification criteria for the different genera. For example, many mycologists do not agree dividing Trichurus and Cephalotrichum into two genera only through the presence or absence of setae. One purpose of this study is to revolve the similar morphological problems by means of molecular biology. The other aim is to increase the biological information of the new species encountered in our study and understand more about their taxonomic status. This study contributes the DNA barcoding project of the fungi.The authors selected LSU SSU and ITS to study the systematics of five genera of Cephalotrichum,Humicola,Scytalidium,Gliomastix and Scolecobasidium. The results of molecular systematics supported the result of morphological classification in great extent, but the different phenotypic characteristics were not recognized equally by molecular analysis.Analysis of the molecular system discovered that the strains of Trichurus were clustered as subgroup in the genus of Cephalotrichum in the phylogenetic trees. The patterns of conidia formation and conidigenous cells proliferation in them are the same type. Trichurus can not be seen as a genus only because the presence of setae, it should be a subgroup of Cephalotrichum, but the characters of setae were most important in recognizing the subgroup. Gliomastix was a polyphyletic genus, ornamentation of spore surface and the absence or presence of conidia ball played an important role in taxonomy. In the genus of Humicola, the molecular method took a great advantage. Humicola fusoatra and Humicola grisea were polyphyletic species indicated by different phylogenetic trees. The strains of Scytalidium can parasite various hosts, molecular analysis proved the genus concept should conclude the species containing dematiaeceous arthroconidia and/or the hyaline arthroconidia. And Scytalidium thermophilum is a multi-line species. The LSU of Scolecobasidium were longer than other genera, they can provided more evolution information. The systematic analysis indicated S. tshawytschae was a monophyletic species, but S. humicola was a multi-line species, but the species of two shaped conidia can not clustered together.According to morphological and molecular systematics, the paper described 24 new species, 3 new names for combination species and confirmed a doubtable species.24 new species: Cephalotrichum castaneum Y.L. Jiang & T.Y. Zhang, Cephalotrichum cylindrosporus Y.L. Zhang & T.Y. Zhang, Cephalotrichum acutisporum J.J. Xu & T.Y. Zhang, Cephalotrichum ellipsoideum H.Q. Pan & T.Y. Zhang, Cephalotrichum inflatum Y.L. Jiang & T.Y. Zhang, Cephalotrichum terricola Y.L. Jiang & T.Y. Zhang, Cephalotrichum macrosporum Y. L. Jiang & T.Y. Zhang, Cephalotrichum oblongum J. J. Xu. & T. Y. Zhang, Cephalotrichum ovoideum Y.L. Jiang & T.Y. Zhang, Cephalotrichum verrucipes Y.L. Jiang & T.Y. Zhang, Cephalotrichum longicollum Y.L. Jiang & T.Y. Zhang, Cephalotrichum robustum Y.L. Jiang & T.Y. Zhang, Cephalotrichum globosum J.J. Xu. & T.Y. Zhang, Cephalotrichum spiralis H.M. Liu & T.Y. Zhang, Gliomastix tibetensis Y. H. Geng & T. Y. Zhang, Humicola chinensis Y.L. Jiang & T.Y. Zhang, Humicola interseminata Y.L. Jiang & T.Y. Zhang, Humicola levis Y.H. Geng & T.Y. Zhang, Humicola pedunclensis W. Zhang & T.Y. Zhang, Humicola subminima Y.L. Jiang & T.Y. Zhang, Scytalidium chinesis Y.H. Geng & T.Y. Zhang, Scytalidium tibetensis Y.H. Geng & T.Y. Zhang, Scytalidium verrucaria Y.H. Geng & T.Y. Zhang, Scolecobasidium anisomerosporum Y.L. Zhang & T.Y. Zhang.3 new combination names:Cephalotrichum columnarium (H.J. Swart) T.Y. Zhang & Y.L. Jiang, comb. nov., Cephalotrichum verrucisporum (Y.L. Jiang & T.Y. Zhang) Y.L. Jiang & T.Y. Zhang, comb. nov., Gliomastix verruculosporium (H?hn.) Y.L. Zhang & T.Y. Zhang, comb. nov..The doubtable isolates of Scolecobasidium sp. (HSAUPâ…¡052546) was confirmed to the species of Scolecobasidium tshawytschae (Doty & D.W. Slater) McGinnis & Ajello.All studied specimens, dried cultures and live strains are deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).