Genetic Diversity And Genetic Structure Of Wild Populations In Metasequoia Glyptostroboides

Metasequoia glyptostroboides is a rare and endangered plant in China and even the world,whose wild populations are only distributed in Lichuan of Hubei Province,Longshan of Hunan Province and Shizhu of Chongqing City.It’s helpful to conservation and managing wild populations of M.glyptostroboides by studying the genetic diversity and spatial genetic structure of them.In this study,5626 wild trees were used as research objects,covering almost all wild individuals of M.glyptostroboides.8 microsatellite primers were used to analyze the genetic diversity and spatial genetic structure of wild populations of M.glyptostroboides comprehensively.We try to visualize the spatial genetic structure of continuous distribution population by using kriging spatial interpolation method in Arc GIS geographic information technology.The main conclusions are as follows:1)The average allele number(A)of wild populations of M.glyptostroboides was12.750,the average allele richness(A_R)was 12.171,and the average observed heterozygosity(H_O)and average expected heterozygosity(H_E)were 0.554 and 0.549.The results showed that the genetic diversity of wild populations of M.glyptostroboides was moderate.2)Genotypic population structure was analyzed with two different programs,which are based on Bayesian methods.The result of STRUCTURE showed that there were two genetic clusters,and GENELAND inferred one genetic cluster.3)Combining genetic information and geographical location,all individuals of M.glyptostroboides were divided into three subpopulations.Northwestern subpopulation(NW)has the highest genetic diversity.The genetic differentiation level between the northwestern subpopulation(NW)and the southern subpopulation(S)was low,and there was a moderate level of genetic differentiation between the northeastern subpopulation(NE)and the NW and the S.4)Through spatial autocorrelation analysis of all individuals,it was found that individuals within 4 km showed significant positive correlation between geographical distance and Kinship coefficients,while there was a significant negative correlation over 4 km ones.