Analysis on the Population Genetic Diversity of an Endangered Plant (Elaeagnus mollis) by SSR Markers

Simple sequence repeat(SSR) markers were used to estimate the genetic structure and diversity of seven populations of Elaeagnus mollis,an endangered plant from the Shanxi and Shaanxi provinces,China.Ten pair primers generated a total of 126 reproducible and discernible loci,among which 114 were polymorphic.At a species level,the proportion of polymorphic loci was 90.79%.The effective number of alleles(N_e) was 1.6072,Nei’s gene diversity index(H) was 0.3166,and the Shannon index(Ⅰ) was 0.4603.At a population level,the proportion of polymorphic loci was 61.99%,N_e=1.5445,H=0.2683,and Ⅰ=0.3815.The coefficient of gene differentiation(G_st=0.2074) showed greater genetic variations occurred within the population than among populations.Gene flow(N_m) was 1.9111>1,which showed that gene interflow occurred among populations,and that genetic differentiation was prevented due to genetic drift.Cluster analysis showed a certain correlation between genetic distance and geographic distance.Mantel test showed a positive correlation between geographic distance and genetic distance,but did not reach a significant level(p>0.05).The results showed that genetic diversity was related to species traits and habitat disturbance.The endangered plants did not necessarily display a lower level of genetic variation.