Effect of Exogenous Superoxide Dismutase on Photosynthesis Character and Resistance in Cotton

Using two types synthetic superoxide dismutase(SOD),Cn.Zn-SOD and Mn-SOD,as materials,the effeet of photosynthesis character and disease resisatance in cotton was studied.The results show that,it could enhance the cotton resistance capability during seeding stage when the seed was immersed in Cu.Zn-SOD(5 mmol/L)for 24 hour before sowing.The same type and same consistence SOD was sprayed on cotton leaves during blossoming stage could relieve midday depression of photosynthesis.Compared with other treatments,the speed of chlorophyll decomposition would be slower when Cu.Zn-SOD(5 mmol/L)was sprayed on cotton leaves during boll opening stage.But its use could not reduce or enhance the photosynthetic rate of cotton leaves.As the same,it could not change chlorophyll content of cotton leaves before boll opening stage.In comparison with Cu.Zn-SOD(5 mmol/L),other treatments such as Cu.Zn-SOD and Mn-SOD had no effect on photosynthesis character and stress resistance in cotton.All the SOD could not enhance the cotton resistance of fusarium wilt and verticillum wilt when they were sprayed on cotton leaves during early growth stage.