Effects Of Exogenous Substances On Physiological Characters Of Wheat Seedlings Under Insecticide Stress

Wheat(Triticum aestivum)is an important grain crop in China.It is very important to improve its yield and quality.The high yield of crops can not be separated from chemical pesticides,but pesticides are also a kind of stress factor that affect crop growth.Many studies have found that chlorpyrifos and omethoate are widely used in China but they have serious stress damage on the physiological characters of crops,which in turn affects the yield and quality of crops.In order to study the alleviation effect of exogenous substances on pesticide stress,98.1% of chlorpyrifos technical material,30% chlorpyrifos marked products and 40% of omethoate marked products were used as test pesticides,Shannong 22 was used as a test plant,salicylic acid,ascorbic acid and choline chloride were used as exogenous substances,determinated the wheat chlorophyll,soluble sugar,free amino acid,soluble protein,proline content,superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POD),glutathione peroxidase(GPX)and catalase(CAT)activity.The results can study the effects of different exogenous substances on physiological characteristics of wheat seedlings under insecticide stress and provide a theoretical basis for alleviating the stress of plants on insecticide.The results showed that:1.The chlorophyll content in the leaves of wheat seedling was increased under chlorpyrifos technical material stress,the chlorophyll content in the leaves of wheat seedling was decreased under the stress of chlorpyrifos and omethoate marked products.Under the stress of different insecticides,carotene,soluble sugar,free amino acid and proline content of wheat seedlings were increased,and the content of soluble protein were decreased.The content of MDA was increased significantly,and the activity of SOD,CAT,POD,APX and GPX of wheat seedling leaves were increased.2.Adding three exogenous substances(SA,ASA and CC)to chlorpyriasis technical material can improve the contents of chlorophyll,carotenoid,soluble sugar,free amino acid and proline of wheat seedling leaves,and reduce the MDA content.The activity of antioxidant enzymes(SOD,POD and CAT)could be increased and there were nosignificant differences in soluble protein content and APX activity.SA and CC could increase the GPX activity of wheat seedling leaves except ASA.In addition to ASA,SA and CC treatment both increased GPX activity in wheat seedlings.3.Adding three exogenous substances(SA,ASA and CC)to omethoate marked products can effectively increase the content of chlorophyll,carotenoid,soluble sugar,free amino acid,proline and soluble protein and decreased the MDA content.The antioxidant enzymes activity(SOD,POD,CAT,APX)could be increased,the GPX activity was decreased and there was no significant difference with the control.Above all,SA,ASA and CC can improve the chlorophyll content of wheat seedling,decrease the accumulation of MDA,increase the content of osmotic adjustment mediators and the activity of antioxidant enzymes,and thus reduce the stress of insecticides damage to wheat seedlings.The results of SA and ASA were better than CC.