1. College of Life Science, State Key Laboratory of Crop Stress Biology for Arid Region, Yangling 712100, Shaanxi, P.R. China
2. College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, P.R. China
3. Department of Plant Agriculture, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON N1G 2W1, Canada
4. Institute for Agri-Food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201403, P.R. China
5. USDA-ARS National Laboratory for Genetic Resources Preservation, 1111 S. Mason Street, Fort Collins, CO 80521, U.S.A.