1. Institute of Nuclear Agricultural Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hua Jiachi Campus, Hangzhou 310029, People's Republic of China; Rice Research Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, People's Republic of China; and Institue of Agricultural and Bio-environmental Engineering, Zhejiang University, Hua Jiachi Campus, Hangzhou 310029, People's Republic of China