Genetic Differentiation Of Odorrana Graminea Species Complex In China Based On The Mitochondrial Gene

The Odorrana graminea species complex belong to the genus of Odorrana in the family of Raninae and are widely distributed in the South of China and Southeastern Asia. The phylogenetic position and taxonomic category of the O. graminea species complex has long been controversial and previous analysis has suggested the nonmonophyly of this complex, however, the phylogenetic relationships, definition of the unknown species and the distribution pattern of the O. graminea species complex are little unknown. In this thesis, the genetic diversification of the O. graminea species complex in China was addressed based on the analysis of two mitochondrial genes and extensively sampling to explore the classification boundary, the geographic distribution and taxonomic components in this complex.A total of 195 individuals from 29 populations in 12 Chinese provinces were collected. Fragments of two mitochondrial genes, i.e., 12 S r RNA and 16 S r RNA, were amplified and sequenced. The newly sequences were aligned and combined, and the total alignment of the combined dataset included 1743 bp. 55 haplotypes were identified among the newly sequences in the O. graminea species complex and phylogenetic relationships were reconstructed based on the dataset of the 55 haplotypes using Maximum Likelihood(ML) and Bayesian Inference(BI) methods. In addition, haplotype network was also estimated using NETWORK and hierarchical anlysis of molecular variance(AMOVA) were performed. The topologies of the ML, BI and haplotype network were identical.The main results include:(1) Three highly divergent evolutionary lineages(denoted as Clade A、B and C) within the O. graminea species complex in China were identified and the supports for these clades were high(BP = 100, PP = 1.0). The average pairwise distance among the three lineages achieved was 4.5%-5.0%, and the three lineages indentified correspond to three obvious geographical regions;(2) Clade A consists of species from 6 provinces surrounding Yungui in the east of the Hengduan Mountain and O. chloronota from Vietnam;(3) Clade B includes species from the southeast of Guangxi, southwest of Guangdong and Hainan provinces in the south of the middle and lower reaches of Pear River as well as the O. graminea from the type locality of Wuzhishan Mountain;(4) Clade C is distributed in the hills of the south of Yangtze River and mountains in the north of the Pear River, and the type locality of O. leporipes were included;(5) Different cryptic species were included in the Chinese O. graminea species complex.Whether sympatric localities exist in the distribution regions of the three different lineages identified in the Chinese O. graminea species complex should be further addressed based on extensively sampling in the contacted regions of the three species. The distribution pattern, origin, dispersal, evolutionary history and speciation of the O. graminea species complex should also be addressed in the future.