1. Dezhou Academy of Agricultural Sciences, Dezhou, Shandong, P. R. China;
2. State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, P. R. China;
3. Institute of Water Saving Agriculture in Arid Regions of China, Yangling, Shaanxi, P. R. China