RAPD analysis of genetic variation in natural populations of Betula alnoides from Guangxi, China

摘要

Random amplified polymorphic DNA (RAPD) markers were used to estimate the genetic variation of seven natural populations of Betula alnoides from Guangxi Zhuang Autonomous Region, China. 16 primers generated a total of 131 highly reproducible and discernible loci, among which 84 were polymorphic. The high genetic diversity was assessed using these RAPD markers at the species and population level, which was congruent with those revealed with allozyme markers, although disparities were found between both types of markers at the single population level. Approximately 90.0% of genetic variance was observed within populations, as revealed with both phenotypic and genotypic RAPD data. The weak differentiation was, perhaps, due to extensive gene flow (Nm < 1.0) of this species in the area. No significant correlation was found between genetic and geographic distances. Based on the results presented in this study, we recommend that a small number of populations represented by large numbers of individuals will be enough for breeding and germplasm conservation purposes, and major attention should be paid to population 2 for conservation and breeding consideration.