1. Paulownia
Research and Development Center, State Forestry Administration, Zhengzhou, Henan 450003, China
2. Key
Laboratory of Cultivation and Protection for Non-Wood Forest Trees,
Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
3. Forestry
Experiment Center of North China, Chinese Academy of Forestry, Beijing 102300, China
4. Southern
Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana 70124, United States