Taxonomic Studies On Fallen Dead Wood Dematiaceous Hyphomycetes From Southwest Of China

Fallen dead wood dematiaceous hyphomycetes are those fungi which have some part of or whole life cycle either in or directly associated with the fallen dead wood. It is a group of organisms which belong to the hyphomycetes in Deuteromycotina. Our country has a vast territory, complicated entironment and abundant vegetation, which accumulate diversiform dead wood as a complex ecosystem, may contains plenty of dematiaceous hyphomycetes resource, but our country has lagged in the study of this fungal groups.Southwest of China (Yunnan, Guizhou, Sichuan Province and Chongqing) are located in the South-western border area and upriver of Yangtse Rive, are a unique geographical area which have complex terrains and notable altitude difference. The Southwest spans several climate zones, covers much tropical and subtropical forest ecosystems, which accumulate abundant fallen dead wood. 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 at genus and species level from Southwest, and layed a foundation for the further study.A total of 400 dead wood samples from many representative sites selected in Southwest were collected, and another 300 were collected from Hainan, Guangxi and Hunan Province under the plentiful of time. 33 species belonging to 12 genera were discovered. Of which, 14 are new species, 1 genus and 6 species are new recorded to China, 13 species are reported from China. All genera and species are fully described and illustrated morphologically. Distribution sites and habitat are also cited.The 14 new species are: Berkleasmium daphniphyllumium Jian Ma & X.G. Zhang,Corynespora beilschmiediae Jian Ma & X.G. Zhang,Corynespora cassiae Jian Ma & X.G. Zhang,Corynespora euryae Jian Ma & X.G. Zhang, Corynespora ficusima Jian Ma & X.G. Zhang,Corynespora gymnocladi Jian Ma & X.G. Zhang,Corynespora lasianthusium,Corynespora litseae Jian Ma & X.G. Zhang,Corynespora myrioneuronis Jian Ma & X.G. Zhang,Corynespora parapyrenariae Jian Ma & X.G. Zhang,Ellisembia artocarpi Jian Ma & X.G. Zhang , Ellisembia sapii Jian Ma & X.G. Zhang ,Minimelanolocus endospermi Jian Ma & X.G. Zhang,Minimelanolocus pterocarpi Jian Ma & X.G. Zhang。The 1 genus newly recorded to China is Listeromyces Penz. & Sacc.The 6 species newly recorded to China are: Cryptophiale kakombensis Pirozynski,Cryptophiale udagawae Pirozynski & Ichinoe apud Pirozynski,Guedea novae-zelandiae Hugues , Listeromyces insignis Penz. & Sacc., Spadicoides obovata (Cook & Ellis) Hughes,Sporidesmium valdivianum (Speg.) M.B. Ellis。The 13 species known to China are: Cordana musae (Zimm.) H?hnel, Cordana Pauciseptata Preuss,Corynespora donae,Corynespora micheliae,Corynespora toonae , Ellisembia bambusicola (M.B. Ellis) W. P. Wu, Ellisembia leptospora (Sacc. & Roum.) W. P. Wu, Ellisembia vaginata McKenzie,Exserticlava vasiformis (Matsushima) Hughes,Guedea ovata Morgan-Jones, R.C. Sinclair & Eicker,Sporoschisma saccardoi E.W. Mason & S. Hughes,Sporidesmium parvum (S. Hughes) M.B. Ellis,Sporidesmium tropicale M.B. Ellis,All specimens examined are deposited in the Herbarium of the Department of Plant Pathology, Shandong Agricultural University (HSAUP). As a result, some useful taxonomic methords, criteria and our viewpoints concerning with this fungal group were conclude;1. Most of this fungal group are saprophytic fungi, which conidial morphology and size are accessible to the culture condition and culture media, and different from that on the natural substrates. So, the morphology of these fungi on the natural substrates should be main identifying bases. Culture feature and sporulation pattern are essential and helpful supplements.2. As the main identification character, the conidiophores, conidiogenous cells extending mode and conidiogenous pattern are key to distinguish these fungi at genus level, but that are not important at species level. In addition to this, the conidial inserted characteristics (catenation or solitary ), character of septation, conidial ornamentation, patterns of conidia formation and conidiophores proliferation are helpful to identify a few hyphomycete genera. At the same time, the character of the setae and whether it formed or not are also useful to differentiate some genera.3. The conidial morphology (shape, size, color, septation, basal cells,ornamentation and appendage) is the main identification base at species level. The characters of conidiophore and conidiogenous cells, and the situation of existence of the setae may be used in seperating in some genera.