Abstract
One of the Japanese birches, Betula maximowicziana is distributed from east of central Japan to Hokkaido. B. maximowicziana is a pioneer tree species and show a fast growth rate in open site such as gaps and have often been found to establish an even-aged stand. Thus, this species plays important roles for stability and sustainability of forest ecosystem as not only major pioneer tree species but also long-lived dominant species in the cool temperate forest. B. maximowicziana is one of valuable natural resources for wood production and its harvesting from natural stand is promoting in these days because of its popularity. Despite these ecological and economic importance of the species and little is known about its genetic variation. Here we investigate genetic diversity within and among 23 natural populations using 11 simple sequence repeat (SSR) makers of nuclear genome and 3 PCR-RFLP markers of chloroplast genome to obtain fundamental genetic information for conservation and forest management of this species. As a results used by SSRs, Intra-popluation genetic diversity were almost similar in every population and revealed no geographic patterns. Population genetic differentiations was relatively low ( FST = 0.062 ). On the other hand, as a results used by PCR-RFLP, two major haplotypes and a rare haplotype were detected. Haplotypes were different in northern and southern area in distributions and poplation genetic differentiation was very strong (FST =0.979 ). These results due to the glacial episodes, gene flow in the past and the present and geographic factors. These results suggest the importance of conservation and management of the regional genetic diversity.
