Pot experiments were conducted in the early seasons and the later season of 2013.In each season,the hybrid rice cultivar Jiyou716 was planted under saturated soil moisture of 95%-100%(W100),80%-85%(W85)and 65%-70%(W70).The results showed that the root growth was seriously limited by soil moisture of W70 at the stage of elongation.The root dry weight significantly decreased.The effect of soil moisture on root diameter was the biggest at the stage of heading,but that on root surface area,volume and dry weight...