Genetic structure and diversity in relation to the recently reduced population size of the rare conifer, Pseudotsuga japonica, endemic to Japan

Rare species consisting of small populations are subject to random genetic drift, which reduces genetic diversity. Thus, determining the relationship between population size and genetic diversity would provide key information for planning a conservation strategy for rare species. We used six microsatellite markers to investigate seven extant populations of the rare conifer Pseudotsuga japonica , which is endemic to the Kii Peninsula and Shikoku Island regions that are geographically separated by the Kii Channel in southwest Japan. The population differentiation of P. japonica was relatively high ( F ST = 0.101) for a coniferous species, suggesting limited gene flow among populations. As expected, significant regional differentiation (AMOVA; p