1College of Grassland Science and Technology, China Agricultural University, Beijing 100083, China 2State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China 3University of Chinese Academy of Sciences, Beijing 100049, China 4National Center of Technology Innovation for Maize, State Key Laboratory of Maize Germplasm Innovation and Molecular Breeding, Syngenta Group China, Beijing 102206, China *Correspondence to:Feifei Yu , Email:ffyu@cau.edu.cn Qi Xie , Email:qxie@genetics.ac.cn