Phylogeography And Conservation Genetics Study Of Pachyhynobius Shangchengensis, Based On MtDNA Control Rigon

The Shangcheng stout salamander (Pachyhynobius shangchengensis) is a narrowly distributed amphibian endemic to the Dabie Mountains, southeast China. We designed the primers of D-loop in mtDNA based on the mitochondrial genome of P. shangchengensis and Ranodon sibiricus from Genebank. By the primers, we amplified175individuals from Baimajian-Yaoluoping-Mingtangshan (BYM), Tiantangzhai-Mazongling (TM), Kangwangzhai-Huangbaishan-Jiufengjian (KHJ) and area around Jingangtai (JGT). These sequences were used to analyse genetic diversity, phylogeography pattern and conservation genetics. The results we got are showed below.1. The low genetic diversity of P. shangchengensis.In TM population,there exists10haplotypes. The haplotype diversity is0.7853±0.0587and the nucleotide diversity is0.0050±0.0034which inhibit relatively higher genetic diversity. Compared with TM population, the KHJ population has2haplotypes and lower genetic diversity (h=0.1079±0.0680; π=0.0001±0.0003). In concluded, TM population holds the highest genetic diversity and KHJ population hold the lowest genetic diversity in the four populations. In addition, when compared with other endangered species, like Andrias davidianus, the populations of P. shangchengensis hold relatively lower genetic diversity.2."Sky Island" led to the phylogeography pattern of P. shangchengensis.Based on the phylogeny and network analyses, two distinct clades were identified corresponding to the two southern populations (TM, BYM) and two northern populations (JGT, KJH). Among them, two southern populations (TM, BYM) are regard as one evolution group. The result is also supported by other analyses, such as AMOVA. After analyses, we concluded that the phylogeography pattern was introduced by the unsuitable environment to the P. shangchengensis in low altitude area which is also named as "Sky Island".3. The history population of P. shangchengensis is influenced by the ice age in PleistoceneThe results of mismatch of the four population show no significant unimodal. Among the four populations, historical demographic analyses (e.g., the g parameter, Tajima’s D test, and Fu’s Fs test) did not reveal definite information on population expansion except for the BYM population, which had undergone a strong population expansion event. Based on the analysis of a Bayesian skyline plot, the total population underwent a significant population fluctuation around20kya. This may have been triggered by the end of the last glacial maximum. In addition, the TMRCA of the population of P. shangchengensis is also in the middle of Pleistocene. Therefore, we got that the history population of P. shangchengensis is influenced by the ice age in Pleistocene when consider the influence of glacial-interglacial cycle on the climate and landscape.4. The divided of relative conservation unit in P. shangchengensis.Evolutionarily significant unit is mean that the relationship on the evolution closely can regard as one unit. But during design a management unit, whether the population isolated from others is considered. In conclusion, the existence of three evolutionarily significant units (BMY-TM, KHJ, and JGT) and four management units (BMY, TM, KHJ, and JGT) is supported by our study.Except the four results, we also analyzed the reason to the species diversity and characteristic species in Dabie Mountain. Because of the special geographical location, complex geographical environment and moderate climate, Dabie Mountain own rich bio-diversity and special phylogeography pattern, like the existence of many endemic species and the split of the species lived on different mountain.