1 State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
2 School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931, USA. Electronic address: hairong@mtu.edu.
3 State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China. Electronic address: wzhang25@njau.edu.cn.