The genetic diversity and the relationships among a collection of Brassica napus accessions, including 20 Chinese, 25 Czech, 2 Germany, 2 Fiance, and 1 England were evaluated using random amplified polymorphic DNA(RAPD) markers. A total of 79 polymorphic amplified products were obtained from 10 decame primers. Three different genetic distances were compared. The Hamman metric based distance was chosen for which the best fit between a priori and a posteriori grouping was found using UPGMA. Cluster analysis b...