1. Department of Research and Development, Kazusa DNA Research Institute, Kisarazu, Chiba, Japan
2. Tohoku Regional Breeding Office, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Forest Research and Management Organization, Takizawa, Iwate, Japan
3. Breeding Department, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Forest Research and Management Organization, Hitachi, Ibaraki, Japan