1. School of Agriculture, Utsunomiya University , Utsunomiya 321-8505 , Japan
2. United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology , Fuchu , Tokyo 183-8509 , Japan
3. Training and Research Institute of Forestry and Wood Industry, Mongolian University of Science and Technology , Ulaanbaatar 5172 , Mongolia
4. Forest Tree Breeding Center, Forestry and Forest Products Research Institute , Hitachi , Ibaraki 319-1301 , Japan
5. School of Industrial Technology, Mongolian University of Science and Technology , Ulaanbaatar 14191 , Mongolia