Effects Of Spraying Cerium Complexes On Degradation Of Chlorpyrifos Residues In Spinach, And Alleviative Effects On Ascorbate-Glutathione Cycle Under Chlorpyrifos Stress In Spinach Leaves

Pesticides have played an important role in protecting vegetable crops from diseases and insect pests, and reducing yield loss. However, due to its improper use, the residues of pesticides cause severe food safety accidents to occurr, which has an serious influence on people's physical and mental health. In the recent years ,pesticides residue as a technical barrier plays increasingly prominent role in international trade of agricultural products.Spinach(Spinacia oleracea L.)is an important variety for vegetable export in China, so its food safety is increasingly concerned. The paper mainly studied effects of spraying alginate and chitosan/ Ce complexes on degradation of chlorpyrifos residues and quality in spinach,and alleviative effects of spraying alginate / Ce complexes on spinach leaves physiological indexes under chlorpyrifos stress,which in order to discuss the feasibility of cerium complexes as the degradation preparation applied in leaf vegetables to degrade chlorpyrifos in the safety production process .This research refers to following aspects:1. Under the greenhouse cultivation condition, the dynamic analysis of chlorpyrifos residues and quality in spinach by spraying different concentrations of alginate and chitosan/ Ce complexes were investigated,and pesticide residues were detected by using GC-NPD . The results showed that chlorpyrifos residues in spinach were in different degrees of degradation by spraying different concentrations of alginate and chitosan/ cerium complexes. 3.3mL/L alginate/ cerium complexes could make the degradation rate reached 59.98% and 10mL/L chitosan/ cerium complexes could make chlorpyrifos degradation rate reached 45.76%. While spraying the two kinds of complexes on spinach had no obvious negative influence on spinach quality, and to some extent it could improve the quality of spinach. The experimental results show that alginate and chitosan/ Ce complexes applied in the growth of vegetables to degrade chlorpyrifos will be feasible.2.Under the greenhouse cultivation condition, the dynamic analysis of chlorpyrifos residues in spinach by spraying proper concentrations of alginate,chitosan and alginate and chitosan/ Ce complexes were investigated . The results showed that chlorpyrifos residues had degraded by spraying alginate,chitosan and its the same concentration of cerium complexes on spinach in some extent, but their cerium complexes could greatly improved the degradation rate of chlorpyrifos residues in spinach; Under the stress of chlorpyrifos ,the contents of vitamin C,soluble protein,soluble sugar,nitrate,oxalate were determined by spraying alginate,chitosan and alginate and chitosan/ Ce complexes on spinach. The results showed that to some extent ,spraying 3.3mL/L alginate/ Ce and 10mL/L chitosan/ Ce complexes on spinach could improve the quality of spinach under the stress of chlorpyrifos. The experimental results show that alginate and chitosan/ Ce complexes as a degradation preparation applied in the growth of spinach to degrade chlorpyrifos will be feasible.3. Under the stress of chlorpyrifos , the effects of alginate cerium complexes on the glutathione and antioxidant enzyme circulation system in spinach leaves were investigated under the open-field condition . The results showed that , comparing with spraying water,there had increased contents of H₂O₂ and decreased contents of ascorbic acid( AsA) and glutathione (GSH),and also increased acttivities of ascorbate peroxidase(APX), glutathione reductase(GR), dehydroascorbate reductase(DHAR) and monodehydroascorbate reductase (MDAR) in the spinach leaves under the stress of chlorpyrifos ;Comparing spraying chlorpyrifos with spraying appropriate concentrations of alginate cerium complexes on spinach leaves, there had decreased contents of H₂O₂ and increased contents of ascorbic acid( AsA) and glutathione (GSH),and the acttivities of related antioxidant enzymes had increased in order to alleviate the chlorpyrifos stress.The experimental results showed that spraying appropriate concentrations of alginate cerium complexes would have an alleviation effects on spinach under chlorpyrifos stress.