1. Graduate School of Environment
and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
2. Department
of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi,
Ghana
3. National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki 305-8604,
Japan