Research On Salicylic Acid Relieve The Toxicity To Three Corps Under The Herbicide Propazine

Pesticide residues are concerned with the two major problems of environmental safety and food safety with the use of pesticides.Effective ways to improve the ability of self-detoxification and degradation of crop,as well as prompt the degradation of pesticides in the environment are among essential issue for crop and environmental safety.Propazine was one of the commonly used triazine herbicides.It has been commonly used in the control of sorghum and other grass weeds.Wheat,corn and rape were three widely cultivated crops in China,and take a very important role in agricultural production in our nation.Salicylic acid(SA),a new kind of plant hormone produced by higher plants in nature,plays an important role in activating plant allergic reactions and obtaining resistance.In this paper,the effects of exogenous salicylic acid on the toxicity and residues of propazine to wheat,maize and rape were investigated.To understand the role of SA in regulating the growth and oxidative stress of three crops to propazine,we first studied the effect of propazine on the growth of three crops.The experimental results showed that the growth of the three crops were inhibited,and the content of chlorophyll in the three crops was significantly decreased when the concentration of propazine in soil planted wheat,corn and rape reached 2,8 and 0.4 mg kg-1 respectively.In addition,the electrolyte permeability of the plant cells increased,indicating that all the crops were damaged by propazine.Therefore,2,8 and 0.4 mg kg-1 were finally selected as the propazine concentrations of soil treatment planted wheat,corn and rape,respectively.In order to study the effects of exogenous salicylic acid on the toxicity of propazine for wheat,corn and rapes,the growth and enzyme activities of wheat,corn and rapes under the propazine stress were investigated.After wheat,corn and rape were planted respectively in soil containing propazine at 2,8,0.4 mg kg-1 for 4 d,salicylic acid was sprayed on the foliage of the crop.The results showed that the treatment of salicylic acid could alleviate the demage of propazine to three crops and the enzymatic activity of the three crops.The chlorophyll content in the three crop leaves was increased in different degrees,and the electrolyte permeability of the plant cells were also decreased.The activities of POD and GST enzyme were also decreased in three crops,indicating that exogenous salicylic acid could relieve the toxicity of propazine for three crops.In addition,the accumulation of propazine in three crops and the residues in soil with planting three crops were determined by chromatography analysis after sprayed SA.Compared with control,the accumulation of propazine in three crops and the residues in soil planted three cropd were significantly decreased under the treatment of SA.It was found that salicylic acid alleviated the toxicity of propazine to crops by reducing the residual propazine in the soil and the accumulation of propazine in three crops of wheat,crop and rape.