1. Kyoto Prefectural Agriculture, Forestry and Fisheries Technology Center, Kameoka, Kyoto, Japan
2. Tohoku Agricultural Research Center, NARO, Morioka, Iwate, Japan
3. Institute of Vegetable and Floriculture Science, NARO, Tsu, Mie, Japan
4. Toyama Prefectural Agriculture, Forestry and Fisheries Research Center, Toyama, Toyama, Japan
5. Hokkaido Research Organization, Agricultural Research Department, Central Agricultural Experiment Station, Naganuma, Hokkaido, Japan