Municipal Bureau of Agriculture,Tai'an 271000,P.R.China;
Yantai Academy of Agricultural Sciences,Yantai 265500,P.R.China;
The lnsititute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,Beijing 100081,PR.China;
College of Horticulture Science and Engineering,State Key Laboratory of Crop Biology,Shandong Agricultural University,Tai'an 271018,P.R.China;