1. Laboratory of Plant Pathology and Biotechnology; Kochi University; Nankoku Kochi 783-8502 Japan
2. Research Center for Ultra-High Voltage Electron Microscopy, Osaka University; Mihogaoka Ibaraki Osaka 567-0047 Japan
3. Graduate School of Agricultural Science; Kobe University; 1-1 Rokkodai, Nada-ku Kobe Hyogo 657-8501 Japan
4. Research Institute of Molecular Genetics, Kochi University; Nankoku Kochi 783-8502 Japan