1. National Institute of Crop Science 2-1-18 Kannondai Tsukuba, Ibaraki 305-8516,, Japan
2. Horticultural Institute, Ibaraki Agricultural Center3165-1 Yasui,Kasama, Ibaraki319-0292, Japan
3. 3Division of Applied Biological Chemistry, Faculty of AgricultureNiigata University2-8050 Ikarashi Niigata 950-2181, Japan
4. 4National Agricultural Research Center3-1-1 KannondaiTsukuba, Ibaraki 305-8666,, Japan