Haijiao Wang1, Xuelu Wang2. 1. National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. 2. National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: xlwang@mail.hzau.edu.cn.