Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2004
Publication Date: 7/24/2004
Citation: Wu, Y.Q., Taliaferro, C.M., Bai, G., Anderson, M.P. 2004. Aflp analysis of genetic variation in cydodon dactylon (l) pers. var. dactylon. Genome. 47:689-696. Interpretive Summary: Cynodon dactylon (L.) Pers. var. dactylon (bermudagrass) is geographically widely distributed species. The extensive variations in morphological and adaptive characteristics are substantially reported, but information on variation in DNA levels for these geographically disparate forms is unknown. Purposes of this study is to understand the genetic relationship among the worldwide collection of bermudagrass using a DNA fingerprinting technique and to provide useful information for breeders to select right parents in breeding programs. We assessed genetic relatedness among twenty-eight C. dactylon var. dactylon accessions originating from nine countries. The accessions were grouped into 5 groups coincided with their geographic origins. Australian and Chinese groups were relatively closer and they all far from European groups. African accessions had the greatest genetic variation. In a breeding program, parent selection to sample maximum genetic variation in C. dactylon var. dactylon would require an extensive germplasm collection from different geographic regions.
Technical Abstract: Cynodon dactylon (L.) Pers. var. dactylon (bermudagrass) is geographically widely distributed between about 45ºN and 45ºS latitudes, penetrating to about 53oN latitude in Europe. The extensive variations found in the taxon for morphological and adaptive characteristics are substantially documented, but information is lacking on DNA molecular variations in geographically disparate forms. Accordingly, this study was conducted to assess molecular genetic variation and genetic relatedness among twenty-eight C. dactylon var. dactylon accessions originating from four continents (Africa, Asia, Australia, and Europe) encompassing nine countries. A fluorescence-labeled amplified fragment length polymorphism (AFLP) DNA profiling method was used to detect the genetic diversity and relatedness. On the basis of 443 polymorphic AFLP fragments from eight primer combinations, the accessions were grouped into clusters and subclusters heavily influenced by geographic origin. Genetic similarity coefficients (SC) for the 28 accessions ranged from 0.53 to 0.98. Accessions originating from Africa, Australia, China and Europe formed major groupings as indicated by SC and principal coordinate analysis. Accessions from Australia and China though separately clustered were relatively closely related and most distantly related to accessions of European origin. African accessions had the greatest variation in genetic relatedness. The extensive variation in molecular AFLP markers is consistent with the high degree of variation in the taxon for morphological and adaptation characteristics. Sampling the full extent of genetic variation in C. dactylon var. dactylon would require extensive germplasm collection in the major geographic regions of it distributional range.