Molecular Phylogenetic Study On The Fungi Of The Genus Cyclamenes From China

The species of Clavulina in temperate zones displays intraspecific morphological variability and interspecific morphological identification confusion.C.cristata complex?C.cinerea complex and C.rugosa complex are three mainly species complex among Clavulina which include more than 20 infraspecific taxa in total,and seemingly intermediate forms between the species cited above are common.These make the morphological identification become more difficult and complicated.Therefore,the study on molecular systematics of Clavulina can improve the understanding of Clavulina phylogenetic relationships,and also provide important clues for molecular systematics of world-wide species of Clavulina.Taking 87 specimens of Clavulina deposited in Microbial Cultures Center of Nanjing Normal University(MCCNNU)which collected from 12 provinces in China as subjects,we constructed phylogenetic trees of Clavulina through methods of Maximum Likelihood(ML)and Bayesian Inference(BI)based on three gene regions including LSU(the 28S nuclear ribosomal large subunit rRNA),ITS(the nuclear ribosomal RNA internal transcribed spacer region)and rpb2(the second largest subunit of RNA polymerase ?).The phylogenetic analyses indicated that Clavulina sp.?C.cf.cristata?C.cf.rugosa?C.cristata complex?C.cinerea complex and C.rugosa complex in China always clustered together in one clade.However,no relationship was found between these species.C.rugosa complex was preliminary confirmed as a monophyletic group.Geographical factors caused the sub-clades forming in monophyletic clade which maybe indicated the on-going process of speciation.The MEGA6.0 software was used to calculated the intra-and interspecific of Clavulina,and evaluated the feasibility of ITS sequence as the DNA barcode of Clavulina.The result shows that the value of maximum intraspecific genetic distance is 0.029,always less than the value of minimum interspecific genetic distance 0.03.And a clear "barcode gap" is displayed.3%ITS sequence divergence is proposed as a threshold for the species delimitation of Clavulina.Combining genealogical concordance phylogenetic species recognition and 3%threshold,14 phylogenetic species of Clavulina distributed in China are recognized ultimately.