Evaluation of genetic diversity and relationshipsin orchardgrass (Dactylis glomerata L.) germplasm based on SRAP markers

The present study is the first report of characterizing the levels and patterns ofgenetic diversity in 60 orchardgrass accessions from four continents by sequence-related amplified polymorphism (SRAP) markers. Twenty-one primer pairs were used to produce 480 bands, of which 405 (84.38%) were polymorphic. The genetic similarity coeffic ients (GS) varied from 0.5863 to 0.9686 among the 60 collections, with an average of 0.7891. The genetic diversity of orchardgrass from China and the United States of America were found to be higher than that found in other countries. The dendrogram and principal component analysis realized from these markers clustered the materials into four main groups. The cluster analysis showed that orchardgrass from Australia was different from other collections in genetic diversity. Accessions from the same continent were classified into the same group, indicating that the genetic diversity of orchardgrass and the entire genetic basis of cultivars used in a continent is narrow. Furthe...