The rice cultivar Dongdao-4, a japonica type elite cultivar in the saline-alkaline land area in China, was used throughout this study.
Seed germination and seedling growth were carried out as described previously (Lv et al., 2013)
. Twenty-five uniformly germinated seeds were selected and pre-cultured for 14 d in a growth chamber (HPG-400HX; Hadonglian In., Beijing, China) at 25/20 _C (light/dark), and 12 h photoperiods