1. National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology Beijing Forestry University Beijing P. R. China
2. Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology Beijing Forestry University Beijing P. R. China
3. The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology Beijing Forestry University Beijing P. R. China