1. State Key Laboratory of Subtropical Silviculture Zhejiang A&F University Lin'an Zhejiang 311300 China
2. Center for Computational Biology College of Biological Sciences and Technology Beijing Forestry University Beijing 100083 China
3. Center for Statistical Genetics Departments of Public Health Sciences and Statistics Pennsylvania State University Hershey PA 17033 USA
4. State Key Laboratory of Tree Genetics and Breeding Research Institute of Forestry Chinese Academy of Forestry Beijing 100091 China