Genetic Diversity of Common Carpetgrass Revealed by Amplified Fragment Length Polymorphism Markers.

Common carpetgrass [Axonopus fissifolius (Raddi) Kuhlm.] is a perennial, warm-season grass. Its low maintenance aspects make it a desirable turfgrass species used in Florida and the lower Coastal Plain in the U.S. There is little information on the extent of genetic diversity at the molecular level among common carpetgrass germplasm. Accordingly, objectives of this study were to assess the genetic diversity and relatedness among 59 common carpetgrass accessions including 49 accessions directly collected from the southeastern United States, one from the GRIN, and another nine derived from commercial seed (designated seed – derived genotypes) produced in Australia using fluorescence- labeled amplified fragment length polymorphism (AFLP) markers. Twenty selected AFLP primer combinations generated a total of 1046 amplification bands, of which 469 (44.1%) were polymorphic. Genetic similarity coefficient among accessions ranged from 0.807 to 0.980. A low level of genetic diversity (I = 0.24, He = 0.16) was observed for this collection. Wild accessions had relatively higher genetic diversity than that of the seed – derived accessions. Accessions from both sources were randomly distributed throughout the dendrogram with no definite geographic or source patterns. More comprehensive sampling throughout its original distribution is needed to increase the genetic diversity of common carpetgrass for breeding.