1. Hokkaido Research Center, Forestry and Forest Products Research Institute, Sapporo 062-8516, Japan.
2. Shikoku Research Center, Forestry and Forest Products Research Institute, Asakuracho, Kochi 780-8064, Japan.
3. Kyushu Research Center, Forestry and Forest Products Research Institute, Kurokami, Kumamoto 860-0862, Japan.