Allozyme Diversity in the Endangered Shrub Abeliophyllum distichum (Oleaceae): A Monotypic Korean Genus

Allozyme analyses for 433 individuals of the endangered monotypic genus Abeliophyllum distichum, endemic to the central Korean peninsula, assessed levels of genetic diversity for five known populations and the species as a whole. Allozyme analyses revealed higher levels of genetic variability compared with 26 other woody endemics (proportion of polymorphic loci, PS=40% vs. 42.5% and Pₚ=35.2% vs. 26.3%; genetic diversity, HeS=0.143 vs. 0.078 and HeP=0.110 vs. 0.056). The high levels of genetic diversity in A. distichum indicate that anthropogenic disruption of habitats is recent (<100 yr) and has not yet greatly reduced the genetic variation in the species. In addition, populations of A. distichum harbor high levels of clonal diversity (mean DG=0.992 and $$G/ N=0.68$$). A moderate genetic differentiation among five populations was observed (mean GST=0.141). Indirect estimates of gene flow (Nm) were 1.52 and 2.10, based on GST and a mean frequency of two private alleles (alleles detected in only one population), respectively. The variation may reflect the outcrossing mode of reproduction, clonal reproduction, and recentness of habitat loss.