1. Northwest A&F University State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau 712100 Yangling Shaanxi China
2. China Agricultural University College of Resources and Environmental Sciences, Center for Resources, Environment and Food Security 100193 Beijing China
3. Chinese Academy of Sciences CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Chengdu Institute of Biology 610041 Chengdu China
4. University of Georgia Department of Plant Biology 30602 Athens GA USA
5. University of Georgia Warnell School of Forestry and Natural Resources 30602 Athens GA USA
6. University of Georgia Institute of Bioinformatics 30602 Athens GA USA