1. Department of Plant Biology, University of Georgia, Athens, Georgia, USA; College of Forestry, Nanjing Forestry University, Nanjing, China.
2. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, USA; College of Forestry, Nanjing Forestry University, Nanjing, China.
3. Department of Genetics, University of Georgia, Athens, Georgia, USA; and College of Forestry, Nanjing Forestry University, Nanjing, China.
4. State Key Laboratory of Tree Genetics and Breeding, College of Forestry, Nanjing Forestry University, Nanjing, China.