1Shanxi Agricultural University, Taigu 030800, P. R. China.
2Nanchong Institute of Agricultural Sciences, Nanchong 637000, P. R. China.
3College of Life Sciences, China West Normal University, Nanchong 637009, P. R. China.
4Maize Research Institute, Shanxi Academy of Agricultural Sciences, Xinzhou 034000, P. R. China.
Email: [email protected]