Preliminary DNA fingerprinting of the turf grass Cynodon dactylon (Poaceae: Chloridoideae)

Identification of different cultivars of turf grasses is often very difficult. In a preliminary attempt to identify different cultivars of Cynodon dactylon (L.) Pers., random amplified polymorphic DNA (RAPD) analyses of some well-known cultivars used in South Africa, i.e. Bayview, Cape Royal, Florida, Harrismith, Silverton Blue, Skaapplaas and Tifdwarf, as well as 10 potential new cultivars, were done. These results were used to determine the genetic distances among cultivars. Only five primers were needed to obtain a specific fragment pattern for each cultivar. The degree of amplification was used as an additional criterion by including all visible fragments, excluding very faint fragments and only including the brightest fragments. The neighbour-joining trees of C. dactylon showed best resolution from the data set with all visible fragments included, although fragment intensity did not affect the tree topology. The cultivars Silverton Blue and Bayview exhibited the greatest genetic variation and two potential new cultivars were identified. RAPD analyses can, therefore, be used to distinguish between different C. dactylon cultivars and to determine the genetic variation between them by calculating genetic distances.