Xitao Li1, Yongyao Xie2, Qinlong Zhu2, Yao-Guang Liu3. 1. State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Plant Functional Genomics and Biotechnology of Guangdong Provincial Higher Education Institutions, South China Agricultural University, Guangzhou 510642, China; College of Life Sciences, South China Agricultural University, Guangzhou 510642, China. 2. State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; College of Life Sciences, South China Agricultural University, Guangzhou 510642, China. 3. State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Plant Functional Genomics and Biotechnology of Guangdong Provincial Higher Education Institutions, South China Agricultural University, Guangzhou 510642, China; College of Life Sciences, South China Agricultural University, Guangzhou 510642, China. Electronic address: ygliu@scau.edu.cn.