Studies On The Taxonomy And Molecular Systematics Of Cercosporoid Fungi From Yunnan And Hainan Provinces In China

Cercosporoid fungi is a group of anamorphic fungi, hyphyomycetes, which have an immensely diversity. They have an important role of biodiversity in nature, because there are many species in the group and their hosts are widely. Cercosporoid fungi are general distributed both tropical and subtropical areas. More than95%of them are pathogen of plants, which have strong parasitism. Some of the species have serious damage to economic plants, as while as people and some animals, but some others are very helpful for killing wild and toxin weed.Yunnan and Hainan are located in the tropical and subtropical areas in China, where are both called "The plant kingdom" because of their rich plant resources. Their special geographic location and abundant plant species decided immensely diversity of fungi.Up to now, the taxonomy of cercosporoid fungi were based on morphology, the taxonomic characters of Cercospora, Pseudocercospora, Passalora and Pseudocercosporella which based on the modern classified viewpoint were:(1) they have conidial scars or not.(2) the color of conidiophores and conidia. Sometimes it is difficult to identify the species of cercosporoid fungi, because their color and size will be changed as while as their environment and hosts are changed.From2010to2013, we collected more than1200specimens in14places of Yunnan and Hainan province and studied more than300specimens in HMAS. Presently the taxonomy of Cercospora and its allied genera mainly bases on their characters which on the host, and also take the host plant range into account. Every species was described carefully, including symptoms, observed the conformation characters of mycelium, stromata, conidiophores and conidia with the microscope, then made the line drawings and the world distribution and referred to sufficient literature to finally confirm their ascription. Through the filtration of about1500specimens we identified and described65species based on careful identification, in which14species of cercospora,9species of Passalora,41species of Pseudocercospora and1species of Pseudocercosporell were included. Among the65species described,1was new species Passalora lepistemonis L.Xia,Y.L. Guo&Y.Li sp. nov.,3were newly recorded species to China Pseudocercospora calopogonii (F. Stevens&Solheim) Deighton, Pseadocercospora macarangicola Deighton and Pseudocercosporella dioscoreae Deighton. These specimen deposited in HMJAU and HMAS. Besides the new species, and the new records, this paper was an important complement on the hosts, symptoms and geography distributions of the reported species to the existing literature.Cercosporoid fungi are difficult to be cultured because they have strong specific parasitism, and they usually grow slowly. We further studied and discussed the results of^identification by biomolecule method。51species were culturaled and the ITS sequence of5species were got by purified, DNA extracted and sequenced, and the sequences of5species were compared with other sequences which on NCBI, then42ITS sequencing of Cercospora, Cercosporella, Pseudocercospora, Pseudocercosporella, Passalora and Cladosporium were transferred from GenBank and NJ were used to built phylogenetic tree and analysed the results. Phylogenetic tree showed more clear profile between the six genus and Cercospora, pseudocercospora, Passalora showed more closely relationships.5species of testing squences were respectively existed in the genus of itself. The results demonstrated the correctness of morphological identification.