ABSTRACT
Rice (Oryza sativa) is one of the most important cereal crops belonging to the grass family (Poaceae) and has the second largest area under production following maize worldwide. The tremendous growth of human population worldwide has increased the demand for rice production (Liang et al., 2010), requiring an improvement of 50% by the year 2025 (Khush, 2001). Rainfed ecosystems contribute to only 25% of the total water supply, thereby making rice more vulnerable to increased frequency of drought stress under the ensuing threat of global climate change. Rice, being a water-loving crop, is severely affected by drought stress that depresses yield by 15-50% depending on the vigour and period of stress (Kumar et al., 2008; Srividhya et al., 2011). Rice is especially sensitive to drought stress during reproductive growth and even moderate stress can result in drastic reduction in grain yield (GY) (Hsiao et al., 1984; O’Toole, 1982; Venuprasad et al., 2008).
