Water is a major limiting factor for food production and many countries fail to produce sufficient food for their population due to severe water scarcity(Jury and Vaux,2005).Rice is the main staple food worldwide.More than 50%of rice in the world is rain-fed and drought causes severe reduction in rice grain yield in rain-fed environments(Venuprasad et al.,2007;Zhang.2007;Sandhu et al.,2014).Therefore,enhancing drought resistance(DR)of rice is important for food security.However,DR is a complex trait,which is controlled by a large number of loci with small effect and is also affected by different genetic background,genotype-by-environment interaction and other stresses such as heat(Hu and Xiong, Water is a major limiting factor for food production and many countries fail to produce sufficient food for their population due to severe water scarcity (Jury and Vaux, 2005). Rice is the main staple food worldwide. More than 50% of rice in the world is rain-fed and drought causes severe reduction in rice grain yield in rain-fed environments (Venuprasad et al., 2007; Zhang. 2007; Sandhu et al., 2014) for food security. Still, DR is a complex trait, which is controlled by a large number of loci with small effect and is also affected by different genetic background, genotype-by-environment interaction and other stresses such as heat (Hu and Xiong,