1. State Key Laboratory of Maize Bio‐Breeding, Key Laboratory of Crop Heterosis Utilization, Ministry of Education Beijing Innovation Center for Crop Seed Technology (MOA), College of Agronomy and Biotechnology, China Agricultural University Beijing 100193 P. R. China
2. Institute of Crop Sciences, Chinese Academy of Agricultural Sciences Beijing 100081 P. R. China
3. Department of Agronomy Iowa State University 2035 Roy J. Carver Co‐Lab Ames 50011‐3650 Iowa USA
4. Sanya Institute of China Agricultural University Sanya 572025 China