1. State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture Northwest A&F University Yangling Shaanxi 712100 China
2. Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture Northwest A&F University Yangling Shaanxi 712100 China
3. College of Enology Northwest A&F University Yangling Shaanxi 712100 China
4. Department of Biological Sciences University of Maryland Baltimore County 1000 Hilltop Circle Baltimore MD 21250 USA