Molecular Phylogenetic Research On Cortinarius In Yunnan Province

Corlinariuns is one of the largest genus of mushrooms in the world,containing an astounding number of species.The fungus of Cortinarius has very important economic value and ecological value,but due to the abundant species diversity,insufficient molecular phylogeny study,furthermore classical classification methods cannot properly distinguish the species in the genus,the classification of this genus has been disputed.In this study,the ribosomal gene including internal transcribed spacer(ITS),ribosomal large subunit(LSU),and ribosomal small subunit(SSU)fragments from 50 samples of the genus Cortinarius from Yunnan province were amplified by PCR,then cloning and sequencing,a total of 108 self-test sequences were obtained for phylogenetic analysis.The ITS sequence and the LSU sequences were separately BLAST-matched with the data in GenBank for preliminary species identification.The Neighboring-Joining method(NJ),the Maximum Likelihood method(ML)and the Bayesian analysis was used to construct phylogenetic trees for each gene fragment,and then the three gene fragments were connected in series and analyzed by three methods.The topology of the phylogenetic tree constructed by different methods compares the phylogenetic information provided by each gene.The results of this study indicate that:The ITS,LSU and SSU sequences of 36 samples obtained in this paper were BLAST,and we constructed the phylogenetic tree using the sequences download from GenBank with a similarity close to 99%.After molecular phylogenetic analysis,36 samples were all of the Cortinarius,Molecular identification results of the sample number of C22(C.semisanguineus),C30(C.collinitus),C42(C.alboviolaceus),C46(C.semisanguineus),C49(C.caperatus)were consistent with the morphological identification results.The 12 phylogenetic trees indicated that 36 samples in this study belong to Subg.Phlegmacium,Subg.Myxaacium,Subg.Dermocybe,Subg.Anomali,Subg.Telamonia,Subg.Leprocybe.And Sect.Anomali is an independent subgenus.Among the three analysis methods,Bayesian analysis provides higher branch posterior probability,and the branch support rate of each sequence in the Neighbor-Joining method(NJ),the Maximum Likelihood method(ML)is not very ideal;Bayesian analysis provides less branch information.Compared with Neighbor-Joining methods,the Maximum Likelihood method is better.The LSU sequence provides more information in the analysis of a single sequence,Therefore,it is reconommended that the LSU sequence could be the main fragment of molecular identification and phylogenetic analysis of the Cortinarius.The ITS and SSU sequences are used as auxiliary fragments,which will allow us to address the major infrageneric relationships of this large genus Cortinarius,and test biogeographic and major evolutionary hypotheses.