A Linkage Map of Common Bermudagrass [Cynodon Dactylon (L.) Pers.] Based on Simple Sequence Repeat Markers.

Common bermudagrass [Cynodon dactylon (L.) Pers.] has been widely used as a major warm-season turf and forage grass in the southern United States and regions with similar climates around the world.  However, genetic mapping resources are limited in the species. Accordingly, the objective of this study was to construct a genetic map for common bermudagrass. A linkage map was developed using a first-generation selfed population derived from a common bermudagrass genotype, A12359 (2n=4x=36). A total of 249 simple sequence repeat (SSR) primer pairs were mapped to 18 linkage groups (LGs). Four markers mapped in both subgenomes were used to identify three pairs of homeologous LGs. The total length of the map is 1094.7 cM with an average marker interval of 4.3 cM, and length for individual linkage groups ranged from 122.3 cM for LG 18 to 12.7 cM for LG 6. Ninety-eight out of 252 mapped loci (39%) were found to be distorted from the Mendelian 1:2:1 segregation ratio. Among the other 154 non-distorted loci, 88 coupling versus 66 repulsion linkage phases were observed to confirm the allopolyploid origin of the common bermudagrass parent. This map could be beneficial for quantitative trait loci mapping, marker assisted selection and other genomic investigations in common bermudagrass.