Effectsofshadingatthefloweringandgrainfillingstagesonosmoticregulationsubstancecontentandprotectiveenzymeactivitiesintheleavesofdifferentricegenotypes(e.g.,IIyou498,Gangyou188,Dexiang4103,Gangyou527andChuanxiang9838)wereinvestigated.TheresultsshowedthatthemalondialdehydecontentofGangyou188significantlyincreasedundershading,whereasthoseofIIyou498,Dexiang4103,Gangyou527andChuanxiang9838showednosignificantdifferencescomparedtothecontrol.ThesolublesugarcontentsignificantlydecreasedinIIyou498,Gangyou188,Dexiang4103andChuanxiang9838,whereasitdidnotsignificantlyincreaseinGangyou527undertheweaklightconditions(shading).Moreover,thesolubleproteincontentintheleavesofdifferentgenotypestendedtodecreaseundershading.Further,theprotectiveenzymeactivitiesintheleavesvariedindifferentricegenotypesundertheshadingtreatment.Basedontheosmoticregulationsubstancecontentandtheprotectiveenzymeactivitiesintheleavesofdifferentricegenotypes,itwasconcludedthatGangyou188andGangyou527hadstrongabilitiestoadapttothelowlightconditions.Inaddition,themechanismofdamagetoriceleavesindifferentgenotypesundershadingwasdiscussed.
