The Morphological Diversity And SSR Marker Of Dactylis Glomerata L.

Dactylis glomerate ssp. glomerata L. (common orchardgrass) is one of the most important member of the genus Dactylis, as a world-famous cool-season forage propagated widely. There is abundant native orchardgrass gerrmplasm in temperate climates zone with great potential of utilization.A study on variations of 11 morphologic features of 39 accessions of orchardgress form five continents showed that there were extensive variations in morphology.On the other hand, genetic variation and relationship of 6 varieties of D. glomerata were analyzed using simple sequence repeat (SSR) molecular marker. The main results as follows:1.There are abundant phenotypic diversities within the different geographical populations and their coefficients of variation (Cv) are between 9.19% and 45.12%, the average is 24.63%.The level of variation in inflorescence width is the highest and its Cv is 45.12%. Furthermore, by hierachical clustering, all 39 populations can be classified into 3 groups, in which those with pendulous inflorescence are in the same group and those with upright inflorescences are in the other two groups. PI610813 from Europe, PI318972 from American and D. glomerata L.CV.Baoxing are in the same group, it demonstrates great potential.The clustering seemed little to do with its geographic origin. Some the same geographical populations were far in clustering, such as PI277836 and PI318972. In the process of adapting to environment, phenotypic variation has been changed significantly. Interactions between genotype and habitat can lead to different morphological features. Domestication and cultivation of new breeding are based on morphologic variation.2.The average number of genetic distance among varieties of D. glomerata is 0.1437 below 0.15.Recently, the varieties bred in China are limited in genetic variation genealogy and the quantity is less. It is nessaary to breed new variety and enrich the geneticdiversity, because of less varieties of D. glomerata under different ecological environments. The wild D. glomerata had high level of genetic diversity and value.We should improve crossing and breed new varieties of D. glomerata by analyzing its genetic background, varietals type, agricultural characters.3.More alleles can be detected, SSR marker is used to study genetic diversity of plants as a molecular marker. In this study, the rate of polymorphic sites was 100%.We know that SSR marker is used to distinguish the genetic differences among the genetic resources in near relationship.