Genetic variation and structure of Rhododendron brachycarpum D. Don, a rare and endangered tree species in Korea

摘要

Rare and endangered plant species are commonly hypothesized to have little genetic variation because of inbreeding, genetic drifts, genetic bottlenecks and/or other factors. We investigated genetic variation in Rhododendron brachycarpum D. Don, a rare and endangered evergreen tree species in Korea, by examining allozyme variation at 13 loci in 200 individuals distributed among 6 populations. As expected, low level of genetic diversity was observed (A = 1.3, P = 29.5%, H-e = 0.075). While a single allele was the most common in almost all the polymorphic loci, two allele frequencies were completely or nearly intermediate at the locus Pgi-2 in all populations, suggesting a selection effect on the Pgi-2. The Uleung Island population (R. brachycarpum var. roseum) had a unique genetic structure and was most distinctive from the inland populations.