1. Institute for Environmental Sciences Department of Radioecology, , 1-7 Ienomae, Obuchi, Rokkasho, Kamikita, Aomori 039-3212, Japan
2. Institute of Fruit Tree and Tea Science Division of Fruit Tree Production Research, , NARO, 92-24 Nabeyashiki, Shimokuriyagawa, Morioka, Iwate 020-0123, Japan