DNA Identification And Spatial Distribution Of Wild Metasequoia Glyptostroboides Individuals

Metasequoia glyptostroboides is known as a"living fossil"plant,and its wild populations are only distributed in small narrow areas in Lichuan of Hubei Province,Longshan of Hunan Province,and Shizhu of Chongqing City.Completing DNA identification of wild M.glyptostroboides individuals can improve the accuracy of population genetic monitoring,which is beneficial to the protection and management of M.glyptostroboides from a genetic point of view.In this study,microsatellite markers were used to study genetic analysis and complete DNA identification of all5636 wild M.glyptostroboides individuals using 12 highly polymorphic microsatellite loci and construct the relationship curve between allele and area.The main conclusions are as follows:（1）Based on high-throughput sequencing method,28 pairs of microsatellite primers with high polymorphism and good reproducibility of M.glyptostroboides were developed,which can be used for population genetic research.（2）A total of 12 microsatellite loci were selected from the above 4 and the original8 for DNA identification of wild M.glyptostroboides individuals,the results showed that the genetic resolution reached 99.77%,and the consistency probability value of any two individuals was low enough(P ID=4.6×10^-12,P IDsib=6.2×10^-5),indicating that 12 SSR loci can distinguish all M.glyptostroboides individuals well.（3）The analysis of population genetic structure based on Bayesian method and spatial interpolation method showed that it can be clustered into two types of genetic population.The two genetic populations are located in the east and west of the distribution area,which was a moderate genetic differentiation between eastern population and western population(F_ST=0.0796).The western population can be further divided into two subpopulations in the northwest and south,which showed a low level of genetic differentiation(F_ST=0.0254)（4）The average allele number（A）of M.glyptostroboides population was 14.2917,the average allele richness（A_R）was 13.4896,the average observed heterozygosity（H_O）was 0.5719,and the average expected heterozygosity（H_E）was 0.6201 when divided into two populations.And the average allele number（A）of M.glyptostroboides population was 14.1944,the average allele richness（A_R）was 14.6017,the average observed heterozygosity（H_O）was 0.5622,and the average expected heterozygosity（H_E）was 0.6264 when divided into three populations.（5）M.glyptostroboides was basically distributed in an aggregated pattern.After excluding the influence of habitat heterogeneity,the obvious aggregated distribution gradually changed to a random distribution as the study scale increased.（6）The fitting equation of the actual population allele-area curve was y=12.832x^0.4545,which was significantly different from the curve under the homogenous Poisson process simulation.The number of alleles was no longer increasing when the sampling area reached 665.64km².