1. Institute of Crop Science, National Agriculture and Food Research Organization (NARO), 2-1-2 Kannondai, Tsukuba 305-8602, Japan
2. Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo 271-8510, Japan
3. Tochigi Prefectural Agricultural Experiment Station, Kawaraya-cho 1080, Utsunomiya 320-0002, Japan
4. Shandong Academy of Agricultural Sciences (SAAS), Crop Research Institute, 202 Gongyebei Road, Licheng District, Jinan 250100, China