1. Graduate School of Agriculture, Kyoto University; Kitashirakawa Oiwake-cho, Sakyo-ku Kyoto Japan 606-8502
2. Dep. of Land, Air and Water Resources; University of California; Davis CA 95616
3. National Institute of Vegetable and Tea Science; Kanaya Shizuoka Japan 428-8501
4. Division of Agriculture; Osaka Prefecture University; 1-1 Gakuen-cho, Sakai Osaka Japan 599-8531