1. The United Graduate School of Agricultural Sciences, Iwate University , Morioka, Iwate , Japan
2. Department of Food, Life, and Environmental Science, Faculty of Agriculture, Yamagata University , Tsuruoka, Yamagata , Japan
3. Department of Agricultural Research and Training , Min.Agri, Blv.30 Juin-Batetela, Kinshasa , D.R.Congo