The Relationship between Relative Water Content of Leaves, Soluble Sugars, Accumulation of Dry Matter, and Yield Components of Rice (Oryza sativa L.) under Water-stress condition during the Generative Stage

Abstract

This study aims to observe the relationship between leaves’ relative water content (RWC), soluble sugar, dry matter accumulation, and rice yield components under water-stress conditions during the generative stage. Six rice varieties were observed under three different water stress treatments: non-stress, moderate water-stress (-0.35 bar), and severe (-0.70 bar). The results showed that under moderate and severe water-stress; the RWC at reproductive stage had correlation with RWC at maturity stage (r = 0.97), colored pollen (r = 0.87), the percentage of grains (r = 0.54) and grain weight (r = 0.57). The RWC at anthesis stage was closely related to the RWC at ripening stage (r = 0.99), the percentage of colored pollen (r = 0.87) and filled grains (r = 0.58), and the weight of grains per hill (r = 0.69). The RWC at the ripening stage was also closely related to the percentage of colored pollen (r = 0.87), the percentage of filled grains (r = 0.61), and the weight of filled grains per hill (r = 0.72). Furthermore, the percentage of colored pollen was closely related to the biomass dry weight (r = 0.47), and the soluble sugars at the reproductive stage were related to the percentage of filled grains (r = -0.68). The soluble sugars at the anthesis stage were closely related to the soluble sugars at the maturity stage (r = 0.75). The result might allow us to use the RWC as a determinant for rice under water stress, and it is important to maintain the RWC under water stress, especially during the generative stage.