Abstract
Genetic variation and geographical diversity of five natural populations of Cryptomeria japonica in western Japan were investigated for nine allozyme loci. Genetic variation of this species was somewhat lower than the other coniferous species. Most of the variation was attributable within population (98.16%) rather than between populations (1.84%). The GST value was only .0156 and genetic distances between populations were also small, averaging .0062. These results indicate that natural Cryptomeria forests in western Japan have maintained relatively middle genetic variation, comparing with the other conifer species, but these populations were not genetically differentiated each other.
