Patterns of allozyme diversity in several selected rare species in Korea and implications for conservation

Because some endemic plants appear to be adapted to a narrow set of environmental conditions with limited genetic diversity, an analysis of population genetic structure is necessary to fully evaluate the impact of rarity on genetic variation. Listed as endangered species in Korea, only few populations of Abeliophyllum distichum, Leontice microrhyncha, Bupleurum euphorbioides, and Berchemia berchmiaefolia were found. A reduced level of genetic variation in B. berchemiaefolia is consistent with the occurrence of a genetic bottleneck and inbreeding. Leontice microrhyncha differed dramatically from other taxa in its observed level of genetic variation, probably due to its predominant selfing. The level of allozyme variation maintained by A. distichum was high for endemic species. Compared to species with similar traits, A. distichum maintained a relatively higher genetic diversity, probably due to floral heteromorphism and preferred outcrossing. Bupleurum euphorbioides maintained a higher genetic diversity due to outcrossing, but at the individual locus, deficiency of heterozygosity prevailed. Probably inbreeding between local neighborhoods was frequent because A. distichum and B. euphorbioides were pollinated by small fly species which might be less effective as a pollen dispersal, and their visits were extremely scarce and controlled by the weather conditions. Since much of the species-to-species variation in genetic diversity is due to the specific ecological and evolutionary history of a species, any management plan developed should be based on historical changes in the population size and distribution to better predict the amounts and patterns of genetic diversity.