Genetic Diversity Of Setaira Viridis (L.)Beauv Population Between Island And Mainland By ISSR Analysis

Islands have long been important models in the study of ecology and evolutionary biology. In this study, we use ISSR markers, by screening out of13primers whose amplified bands were clear, stable, and of rich polymorphism, to analyze the genetic diversity of the195individuals of8populations of Setaira viridis (L.)Beauv from Shandong Province, Hebei Province and Liaoning Province. We aim to explore the genetic diversity, genetic structure and the characteristics of the genetic differentiation between the island populations and the mainland populations in different environmental conditions. The results of this study include:(1) A total of148discernible loci were detected, of which119were polymorphic loci, the ratio of polymorphic loci was80.41%, the Shannon information index (I) was0.3661and Nei ’genetic diversity index (H) was0.2376, indicating that the Setaira viridis populations had a relatively high level of genetic diversity; gene differentiation among8Setaira viridis population (Gst) was0.2931, reflecting a certain degree of genetic differentiation among populations; and the gene flow (Nm) was1.2062, showing that the geographic isolation had not limited the gene flow among the Setaira viridis populations;(2) According to the genetic distances and genetic consistency of8populations, by using the UPGMA cluster analysis,we obtained the genetic tree; four island populations were clustered as a group, and four mainland populations were clustered as a group;(3) We compared the genetic diversity, gene flow size between the island populations and the mainland populations; the genetic diversity of island Setaira viridis population was70.30%, slightly higher than the mainland population (genetic diversity was68.24%), the gene flow (Nm) of island populations was2.5255, greater than the mainland population’s gene flow (Nm=2.1588), indicating that island geographical isolation of Setaira viridis population have no significant impact on genetic differentiation between the populations. Analysis shows that there is relation between the formation of4Island, habitat and biological characteristics of Setaira viridis.