1. Department of Botany Graduate School of Science Kyoto University Kyoto 606‐8502 Japan
2. Center for Bioscience Research and Education Utsunomiya University Utsunomiya Tochigi 321‐8505 Japan
3. Department of Environmental and Life Sciences School of Food and Nutritional Sciences University of Shizuoka Shizuoka 422‐8526 Japan
4. Department of Bioinformatics College of Life Sciences Ritsumeikan University Kusatsu Shiga 527‐8577 Japan