Association Mapping of Cadmium Resistance in Bermudagrass (Cynodon Dactylon )Based On SSR Analysis.

Cadmium (Cd) is one of the most famous toxic pollutants. Cynodon dactylon L. was identified as a potential plant in phytostabilisation of Cd polluted soil. The objectives of this study were to get the gene loci closely linked to bermudagrass Cd resistance. Six natural populations originating from throughout China, with ability of resistance to Cd ranging from sensitive to tolerant, were used for molecular marker genotyping using SSR. The software STRUCTRE was used to evaluate the structure of the population based on the test of 707 SSR markers distributed evenly in bermudagrass genome.The association was analyzed between polymorphic markers and seven phenotypic and physiology traits through the GLM model with the software TASSEL.Genetic structure analysis showed that the wild populations were composed of three subpopulations, which associated with their geographic ecotypes. Four SSR loci associated with the traits were screened out from wild populations. There was a loci associated with three traits simultaneously, which might be the genetic reason of positive correlation among traits as well as the pleiotropic effects of gene. These results suggest that association mapping approaches may be feasible in bermudagrass. This study will improve the understanding of the Cd-resistant molecular mechanism in wild bermudagrass and promote the use of genetic resources of wild bermudagrass in Cd resistant breeding.