| The changes of photosynthetic parameters in the leaves of wheat treated by exogenous nitrogen were studied under 38℃ heat-stress.The results showed: under the condition of moderate heat-stress,the contents of chlorophyll and soluble protein,Fv/Fm,ФPSⅡ and apparent quantum yields in the leaves were slightly reduced,and NPQ and photosynthetic rate of light-saturation were increased when the plants were treated by low-concentration nitrogen;however,the contents of chlorophyll and soluble protein,apparent quantum yields,photosynthetic rate of light-saturation,Fv/Fm and ФPSⅡ were enhanced,and NPQ was reduced when the plants were treated by high-concentration nitrogen.It is concluded that applying exogenous nitrogen nutrition can improve the foliar photosynthesis ability of wheat and alleviate photosynthetic damage by heat stress. |