Genetic diversity in three species of Forsythia (Oleaceae) endemic to Korea: Implications for population history, taxonomy, and conservation

<p>As the mountains in temperate regions have been hypothesized as refugia for boreal and temperate plants during the Last Glacial Maximum, one would expect high within-population genetic variation and low or moderate among-population differentiation for those species occurring there. We selected Forsythia ovata and Forsythia saxatilis, endemic to limestone mountains of Korea, to test the scenario that limestone ranges would also have acted as refugia. We undertook a population genetic analysis using 14 putative allozyme loci of the two species and the widely cultivated Forsythia koreana. We found relatively high levels of genetic diversity and low to moderate among-population differentiation in F. ovata and F. saxatilis, which are consistent with the proposed scenario. Allozyme data revealed that F. ovata and F. saxatilis are likely conspecific. As many populations of F. ovata and F. saxatilis have experienced dramatic decreases in their size, a comprehensive conservation program is urgently needed.</p>