1. Gansu Provincial Key Laboratory of Arid Land Crop Science/Faculty of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
2. Faculty of Resource and Environmental Science, Gansu Agricultural University, Lanzhou 730070, China
3. E H Graham Centre for Agricultural Innovation (Alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, PMB, Wagga Wagga, NSW 2650, Australia