| The spatial genetic structure（SGS）is a spatial distribution pattern of genetic variation of populations.The studies on the measure,drivers and dynamics of spatial genetic structure of population is an important part of evolutionary biology and population ecology.In the researches of SGS of birds,a“kin groups”showed in some highly social birds,and the positive fine-scale spatial genetic structure is related to breeding strategies of individuals,competition and cooperation,and adaptation to environmental changes.However,the causal relationship between the behavior strategies of individuals and genetic parameter of populations is under debate.My study took the azure-winged magpie（Cyanopica cyanus）bred in a high-altitude habitat as the research object,then proposed and tested the hypothesis that the behavior strategies of individuals are a main driver of fine-scale genetic structure of the population.Due to habitat fragmentation,samples were collected from 5 different colonies along the Tao river at Luqu county in the northeast genetic diversity of the Tibetan Plateau,Tibet Autonomous Region,China.The present thesis analyzed the genetic diversity,genetic structure,genetic differentiation and gene flow of the azure-winged magpie from temporal and spatial scales based on field data and microsatellite data over the past ten years.Firstly,genetic diversity was assessed by calculating genetic diversity parameters from different colonizing years,and factors that may be correlated with the genetic parameters were tested by fitting Generalized linear models（GLMs）.Then the fine-scale spatial genetic structure was assessed in different colonies and different sex using Spatial autocorrelation analysis and Sp values.Finally,the different degrees of genetic differentiation of the population were detected at temporal and spatial scales.I demonstrated the main driver of the spatial distribution pattern of genetic variation of the population of the Tibetan azure-winged magpie base on previous studies with respect to life histories and behavior strategies.The main results obtained are shown below.The results of genetic diversity parameters showed（1）the mean numbers of different alleles were 6.740,The average values of observed heterozygosity were 0.762,and the average expected heterozygosity was 0.762.（2）the average values for inbreeding coefficient were 0.027,but differed largely among colonizing years.（3）the mean allelic richness was 5.450 and the mean gene diversity was 0.793.The population of the azure-winged magpie has a high genetic diversity.The results of fitting generalized linear models（GLMs）to test factors that may be correlated with the genetic parameters showed（1）the gene diversity of the colonies increased significantly with the year of colonization.（2）the allelic richness was negatively related to colonization time.（3）the inbreeding coefficient increased firstly and then decreased with colonization time.The results also revealed other genetic diversity parameters were not significantly correlated with the time of colonization.The results of the temporal changes of genetic structure showed（1）2.97%the genetic variance was detected from the same colonies in different years（P<0.001）.（2）the genetic structure differed among colonizing years using STRUCTURE.The results of the fine-scale spatial genetic structure within colonies using spatial autocorrelation analysis and Sp values showed（1）the significant fine-scale spatial genetic structures were detected within a radius of 10 m and 10-20 m in 4 of 5 colonies.（2）pairwise relatedness did not differ from that expected by chance over short distances for females.However,significant positive genetic structure for males was detected at a scale of less than 10m,which revealed sex-biased dispersal behavior.The results of genetic differentiation of the population at temporal and spatial scales showed（1）significant variation was detected in populations from different years for same colony by computing Fst values,and the further genetic distance was showed among samples from different years for same colony according to the NJ dendrogram.（2）The low levels small genetic differentiation among different colonies were observed because of high levels of gene flow.The genetic differentiation of the azure-winged magpie was in accordance with the pattern of isolation by distance（IBD）,the genetic differentiation among populations is influenced by geographic distance.Above all,in the process of colonization of the population of Tibetan azure-winged magpie,a high level of the genentic diversity was observed in different colonization years;the genetic structure was unstable and characterized by significant fluctuations at temporal scales;the significant sptial genentic structure was detected in colonies generally,and there was no significant genetic differentiation among colonies due to the high level of gene flow.Therefore,the high potential for adaptation and evolution was predicted for the population. |
