1. State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University , Tai-An 271018, Shandong , China
2. National Agricultural Engineering Center for North Mountain Region of the Ministry of Science and Technology, Mountainous Area Research Institute of Hebei Province, Hebei Agricultural University , Baoding, Hebei 071001 , China