1. United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan;
2. School of Agriculture, Utsunomiya University, Utsunomiya, Japan;
3. Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Japan;
4. Kyushu Regional Breeding Office, Forest Tree Breeding Center, Koshi, Japan;
5. Department of Wood Properties and Processing, Forestry and Forest Products Research Institute, Tsukuba, Japan (Research Fellow of Japan Society for the Promotion of Science)