Detection Of Genetic Diversity In Stipa Grandis Using RAPD Markers

Stipa grandis is one of the most important forage in typical steppe. It has the broadest distribution in Inner Mongolia. In this study,random amplified polymorphic DNA(RAPD) analyses was used to estimate the genetic diversity and ecological variations and explore connection of grazing intensity and genetic variation of S. grandis. A total of 16 primers were used to detected seven populations of S. grandis in different region. The polymorphic products percentage was 89.55%,testified individual exist very high genetic variation. Aelle frequency proved particular loci have relation with geographical location. Genetic diversity of intra-population (0.5866,0.6189) is higher than inter-population (0.4134,0.3811),also testified genetic variation in intra-population. The result of genetic distance was identical to geographic distribution. A total 18 primers were used to detected grazing population and CK,The polymorphic products percentage was 81.40%. There were particular loci in two populations. Overgrazing pressure cause some loci changed,but genetic variation mostly exist in intra-population (genetic identity is 0.9043). Adjoining populations could magnify gene flow (Nm is 2.5302),resulted in genetic variation is very small.