| The Tsinling Mountains and the Dabashan Mountains are located in the central part of China, parallelly stretching roughly from west to east. The middle parts of these two mountain systems are separated from each other by the Hanzhong Basin. The Mount Taibai with an altitude of3,767m is the highest peak of Tsinling Mountains, the Mount Shennongjia with an altitude of3,105m the highest peak of the Dabashan Mountains. Considering their locations, similar topography, similar climate and similar flora and fauna, customarily, these two mountain systems are given a common name Tsin-Ba Mountains. The Tsinling Mountains are boundary between Oriental realm and Palaearctic realm according to the zoogeographical regions of China. It is also the watershed for Yangtze River and Yellow River catchment areas, and a barrier between the southern and northern part of China, with differences in their climate, flora and fauna compositions. The Oriental and Palaearctic species congregate here forming a specific biotic province. The Tsinling Mountains are one of centers for the origin and evolution of biodiversity in China. This is a region with high biodiversity in both animal and plants. The complex topographic structure, the high diversity of vegetation and climatic factors on the Tsinling-Dabashan Mountains could influence genetic diversity, population genetic structure and phylogeographic structure of animals habit these areas.Like other regions in the northern hemisphere, the Tsin-Ba Mountains also experienced several glacial-interglacial cycles. The past climatic events, such as the Quaternary glaciation, could have left vestiges in geographical distribution of genetic diversity of population. The founder effect leads to reduction of population genetic diversity, and the subsequent rapid population expansion may erase the previous geographical differences of the genetic diversity.The present study aims to explore the effect of the Quaternary glacial actions on the genetic diversity, phylogeographical pattern and demographic history of the ground beetle Chlaenius costiger (Schaller)(Coleoptera, Carabidae) in the Tsin-Ba mountainous areas. This species is widely distributed in Southeastern Asia. In this study, the mitochondrial DNA (Coxl-tRNALeu-Cox2) was used as a molecular marker to examine the geographical distribution of the genetic diversity and its historical process in the Tsin-Ba Mountain area. Genetic diversity and demographic history of the ground beetle Chlaenius costiger (Coleoptera:Carabidae) from the Tsinling-Dabashan Mountains, central China, were estimated using mtDNA sequences (Coxl-tRNALeu-Cox2) on144individuals from16local populations. The resule as follow:the total length of1318bp sequence fragments of the Chlaenius costiger is with647bp belong to the647bp belong to the mitochondrial enzyme cytochrome oxidase Ⅰ (Col),63bp for leucine sequence and608bp for mitochondrial enzyme cytochrome oxidase Ⅱ (Coll). There are32polymorphic site in the analyzed sequence, composing of22parsimony informative sites and10singleton variable site. The haplotype diversity (Hd-0.798) of the total population were high. But the nucleotide diversity (Pi=0.0026) were considerable low. The sharing haplotypes take up about20.93%of the all haplotypes, the single haplotypes that lowing frequency occupy79.07%of the total haplotypes. With analyzing, the transition is greater than transversion (ti/tv=6.807). Phylogenetic analysis by43haplotypes (Bayesian analysis) haplotypes can be divided into two single evolutionary branch (HaplogroupA-B), Analysis of AMOVA, Fst values show that variation occurs mainly within the populations (79.26%), while among populations only accounts for20.74%, and the variation within the haplogroups only take up42.67%. the analysis from SAMOVA and PERMUT indicate that the pedigree of the population does not exist obvious geographic structure (NST=0.210>GST=0.145;p=0.0526).The result of the neutral test for the populations and the two haplogroups can find that the Fu’s Fs value is significant negative, and the Tajima s D value only in HaplogroupB is the significant negative. At the same time, either in the all population or in every Haplogroups, the mismatch distribution resule of the pairs difference are presented a single peak distribution. The result of neutral test and the mismstch distribution hanve proved that the specie happened suddenly rapid expansion in the history. |
PDF Full Text Request