关键词: 广西甜茶, 遗传多样性, ISSR, 遗传分化, 基因流

Abstract:

In this study，the genetic diversity of germplasm resources of Rubus suavissimus Lee was analyzed by ISSR（Inter simple sequence repeats）molecular marker technique. Fourteen ISSR primers were used to amplify 85 DNA samples which were extracted from the individuals of four natural populations of R. suavissimus. A total of 164 bands were detected，of which 148 bands were polymorphic with a polymorphic proportion of 90.24%. At the species level，the Nei’s genetic diversity（H_e）and and Shannon’s information index（H_o）were 0.2514 and 0.3875，respectively. R. suavissimus maintained a relatively high genetic variability at the species level.，PPL range from 57.32% to 68.90% with a mean of 61.74%，H_e range from 0.1831 to 0.2161 with a mean of 0.1958，H_orange from0.2776 to 0.3264 with a mean of 0.2956. And there was a lower middle genetic variability at the population level.Although most variation consistently originated from the interior of populations which was detected based on Nei’s genetic diversity analysis and analysis of molecular variance，a significantly genetic differentiation existed among populations（P < 0.01，Φ_st = 0.262 > 0.25）. A mantel test indicated there was a significant relationship between genetic distance and geographic distance among the populations studied（r = 0.967，P < 0.05）. The result of UPGMA clustering analysis was basically similar to that of the principle coordinate analysis（PCA），and four populations could be classified into two distinct genetic groups. Given the lower middle genetic variability at the population level and a serious habitat destruction and indiscriminate digging Luancai in the species，the populations of R. suavissimus faces the threat of degradation，and it should be taken practical measures to enhance the protection and rational utilization of resources for the species. At the population levelS.

Key words: Rubus suavissimus, genetic diversity, ISSR, genetic differentiation, gene flow