【Abstract】 RAPD technique was used to detect the genetic relationship among seven Betula species.233 loci in total were amplified by using 14 random primers.The percentage of polymorphic loci varied from 12.02% to 36.91%,in which B.costata had the highest variation level.The dendrogram of genetic relationship was constructed on the basis of the genetic distances among species.According to genetic distance in more than 1.22,six species were clustered into two groups,where B.fruticosal was one group and others,including B.davurica,B.pendula,B.platyphylla,B.schmidtii and B.costata, were grouped together.It indicated that the result of genetic relationship obtained by RAPD technique was closely consistent with that classified by traditional morphological classification.The analysis of genetic relationship among Betula species would validly guide the parental selection and interspecies crossing for Betula species.更多还原