1. Graduate School of Science; Hiroshima University; Higashi-Hiroshima; 739-8526; Japan
2. Genome Resource Unit; National Institute of Agrobiological Sciences; 2-1-2 Kannondai; Tsukuba; Ibaraki; 305-8602; Japan
3. Institute of Plant Science and Resources; Okayama University; Kurashiki; 710-0046; Japan
4. Institute of Radiation Breeding; National Institute of Agrobiological Sciences; Hitachi-Ohmiya; 219-2293; Japan
5. Faculty of Life and Environmental Sciences; Prefectural University of Hiroshima; Shobara; 727-0023; Japan
6. Institute of Low Temperature Science; Hokkaido University; Sapporo; 060-0819; Japan