1. College of Life Sciences and State Key Laboratory of Crop Stress Biology for Arid Areas; Northwest A&F University; Yangling Shaanxi 712100 China
2. Büsgen-Institute, Department of Forest Botany and Tree Physiology; Georg-August University; 37077 Göttingen Germany
3. College of Plant Protection; Northwest A&F University; Yangling Shaanxi 712100 China
4. National Engineering Laboratory of Tree Breeding; College of Life Sciences and Biotechnology, Beijing Forestry University; Beijing 100083 China
5. Key Laboratory of Environment and Ecology in Western China of Ministry of Education; College of Forestry, Northwest A&F University; Yangling Shaanxi 712100 China
6. Institute of Environment Sciences, Department of Biology Science; University of Quebec at Montreal; Montreal C3H 3P8 Canada