Abstract:

In this study， SSR molecular markers were used to analyze the genetic diversity and population genetic structure of bermudagrass （Cynodon dactylon） in Henan Province. A total of 173 bands were amplified by 10 pairs of primers， of which 163 bands （94.29%） were polymorphic， indicating that the polymorphism of tested accessions is rich. The coefficient of genetic differentiation among the 15 populations was 0.3857， meaning that 38.57% of the genetic variation occurred between populations and the majority of the genetic variation occurred within populations. The gene flow among populations was 0.7964， and there was a degree of gene communication among populations. The genetic identity among different populations ranged from 0.746 to 0.964， with an average of 0.767. A UPGMA cluster analysis among the 15 populations showed that the populations were not clustered completely according to geographical origin. A Mantel test between genetic distance and geographical distance matrix showed that there was no correlation between genetic distance and geographical distance among populations. The genetic distance between 288 bermudagrass accessions ranged from 0.0173 to 0.5205， with an average of 0.3113. According to the UPGMA cluster analysis results， the 15 studied bermudagrass populations fell into three groups. Meanwhile， structure analysis suggested that the 288 bermudagrass accessions could be grouped into two subpopulations and one mixed population， which was basically consistent with the grouping results based on UPGMA clustering. This indicated that the two subpopulations had a single genetic background， while the mixed population had additional germplasm gene penetration， and the genetic background was complex.

Key words: Henan Province, bermudagrass, genetic diversity, genetic differentiation, genetic structure