1. Gene Research Center and Graduate School of Life and Environmental Sciences, University of Tsukuba
2. Present address: Department of Biology, Division of Molecular Biology, Pamukkale University
3. Graduate School for Biosystem Studies, University of Tsukuba
4. Biological Resources Division, Japan International Research Center for Agricultural Sciences
5. Present address: Department of Biotechnological Science, Kinki University
6. Present address: Genebank, National Institute of Agrobiological Resources