The Population Genetic Structure Of Asiatic Toad(Bufo Gargarizans)

Understanding of the genetic structure of natural populations is a main concern in of Evolutionary Biology.In nature,individuals of the same species usually form genetically different populations due to their geographical location,ecological environment,and behavior as well.Change in gene flow is one of the most important factors affecting the degree of genetic differentiation and the pattern of population genetic structure.And,important gene flow can reduce the opportunity of population genetic differentiation and structure.The study of population genetic structure not only can help the understanding of the historical evolution of populations and species.They also appreciate the evolution potential,provide the basis of the genetic background for the ecology,behavioral science,and biodiversity Conservation actions.The Asiatic toad,Bufo gargarizans is an amphibian species widely distributed and adapted to different ecological environment in China.Several aspect of the biology of this species have been studies,including the reproductive behavior,life history and genetic background,and phylogeography.But however,our understandings of the genetic structure of B.gargarizans should be still incomplete because no study has covered the species' entire distributional range.In this study,110 samples samples from twenty B.gargarizans geographic populations were collected,and two molecular markers mtDNA,NADH2 and six microsatellite were used to analyze genetic structure and dispersal patterns of the population,and the results of this study were as follows:(1)The analysis of NADH2 gene fragments:the number of haplotypes was 47,the average haplotype diversity was 0.971,the average nucleotide diversity was 0.03989,the analysis of genetic diversity on the six microsatellite loci showed that the average number of allele was 12.83,the average polymorphism information content was 0.750,the average observed heterozygosity was 0.567,the average expected heterozygosity was 0.772,indicating a high level of genetic variability.(2)By analyzing the degree of genetic differentiation,based on mitochondria data,we found that the range of FST which significant P values was 0.1791-1.0000.And,the range of Nm with significant P values was 0.000-1.1456.And,based on microsatellite data,we found that the range of FST and Nm with significant P values was 0.0516-0.6353,and 0.1435-4.5950 respectively,suggesting that most B.gargarizans populations have obvious genetic differentiation.(3)Neibor Joining phylogenetic results based on the mitochondria data showed that twenty B.gargarizans populations were divided into four genetic groups.And,comparison of the clustering results based on the microsatellite data showed a broadly consistent result.The yunnan-guizhou plateau region and the minnan mountains area were relatively clear groups.Other geographic populations existed in multiple group,so the heritage background of these populations were more complicated.(4)The analysis of significant genetic differentiation index(FST)and gene flow(Nm)between 20 geographic populations(163 pair)based on mtDNA data and microsatellite data showed that the values of FST of microsatellite data was most less important than the FST of mtDNA data.And the total FST of microsatellite data was also significantly less important than the total FST of mitochondrial data;the Nm of microsatellite date was also significantly large than the Nm of mitochondrial data.The result may be due to male sex-biased dispersal in B.gargarizans.This pattern of dispersal affected the genetic differentiation of B.gargarizans population.We choose B.gargarizans as the research object to explore the Population genetic structure,to know the influence of dispersal to population genetic differentiation,to provide a new case of amphibian population structure and dispersal research,and information for the management and conservation of species and habitats.