1. Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography; the Chinese Academy of Sciences; Urumqi 830011 China
2. Institute of Botany; the Chinese Academy of Sciences; Beijing 100093 China
3. Shrub Sciences Laboratory; Intermountain Research Station; Forest Service, US Department of Agriculture Provo UT 84601 USA
4. Komarov Botanical Institute; Russian Academy of Sciences; St Petersburg RU-197376 Russia
5. School of Life Science; Shihezi University; Shihezi 832003 China