Genetic Polymorphism Of Three Cool-season Turfgrass

Perennial ryegrass, Kentucky bluegrass, tall fescue are clearly the most three important and widely used cool-season forage and turf grasses, exhibiting rapid establishment, good tillering ability and high performance. However, in the past, the breeding of superior varieties was often hampered by the extreme complexity of the genome. A sample set of registered cultivars was used to evaluate the capability of RAPD to analysis the genetic relationship, including 16 ryegrass cultivars, 16 bluegrass cultivars, 7 tall fescue cultivars, and the morphological characters were observed.1. 16 ryegrass include 2 accessions annual cultivars and 14 entries perennial cultivars, and 61 RAPD primers were used. 61 RAPD primers generated 408 bands, of which 367 bands (89.95%) were polymorphic.It showed that the coefficient among the cultivars fell between 50%~95%, and mostly of them fell between 85%~95%. Dendrogram obtained using these molecular markers are not in agreement with their separated morphologic character. High correlation was not obersved between the two annual ryegrass cultivars.2. The genetic polymorphism of 16 bluegrass cultivars, including 15 accessions Kentycky bluegrass cultivars and 1 entries Canada bluegrass cultivars from different breeding company were analysed using 25 RAPD markers. 25 RAPD primers generated 218 bands, of which 196 bands (89.91 %) were polymorphic. It showed that the Canada Bluegrass was separated from other Kentucky Bluegrass and genetic polymorphism in the Canada Bluegrass cultivars was low, the coefficient among thecultivars fell between 66%~98%. Dendrograms obtained using these molecular markers were partly in agreement with their separated morphologic character. Cultivars from the same company were not clustered in one group.3. The genetic relationship of 7 tall fescue cultivars with known breeding method were analysed using 11 RAPD primers, 69 bands were generated of which 76.81% was polymorphic, it showed that the polymorphism was very low, the coefficient among the cultivars fell between 88.64%~96.84% except for Houndog. Houndog was separated from other cultivars, and consistency was not observed between the dendrogram and their breeding history. The breeding method of the three species was discussed.