1. Kyushu Regional Breeding Office, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Kumamoto, Japan
2. Institute of Natural and Environmental Sciences, University of Hyogo, Hyogo, Japan
3. Tohoku Regional Breeding Office, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Takizawa, Japan
4. Breeding Department, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Ibaraki, Japan
5. Hokkaido Regional Breeding Office, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Ebetsu, Japan