基于ISSR分子标记的云锦杜鹃遗传多样性研究OA

The genetic diversity of four natural populations of Rhododendron fortunei in China was studied using the inter-simple sequence repeat(ISSR)molecular marker technique.The results showed that a total of 189 polymorphic sites were amplified by 8 primers,and the polymorphic site ratio was 98.44％.The Nei's gene diversity index,Shannon's information index,the number of observed alleles and effective alleles at the species level were 0.233 1,0.374 5 1.989 6 and 1.364 0,respectively.The genetic diversity index at the population level was 0.235 0,the average genetic diversity index among populations was 0.0681,the average genetic diversity index within the population was 0.166 9,and the coefficient of genetic differentiation was 0.290 0,which indicated that the genetic diversity level of R.fortunei was low.The AMOVA molecular difference analysis showed that 29％of the variation existed between populations,and 71 of the variation existed within populations,that significant genetic variation had occurred within the populations of R.fortunei,and the genetic differentiation among populations was small;the gene flow among the populations of R.fortunei was 1.224 4＞1,indicating that was a certain degree of gene flow among the populations,which could prevent the genetic differentiation caused by genetic drift.The cluster analysis based on genetic distance of the four populations of R.fortunei showed that the population in Guangxi Shilipingtan was closely related to the population in Jiangxi Jinggangshan,and the gene exchange level between the two populations was high;the population in Guangxi Maoershan was distantly related to the other three populations,and the degree of genetic differentiation was high.