1. School of Agriculture, Ibaraki University, Ibaraki, 300-0393 Japan
2. All Russia-Research Institute for Agricultural Microbiology, Shosse Podbelskogo 3, St. Petersburg-Pushkin 8, 189620, Russia
3. Tokyo University of Agriculture and Technology, Fuchu, 183-8509 Japan
4. National Institute of Agro-Environmental Sciences, Tsukuba, 305-8602 Japan
5. National Institute of Agrobiological Resources, Tsukuba, 305-8602 Japan