Effects And Mechanisms Of Silicon Application On Cadmium Uptake In Different Rice Varieties

The prevention and control of heavy metal pollution is one of the hot and difficult problems in the world.In recent decades,due to mining,sewage irrigation,waste discharge and fertilizer irrational use,China’s cadmium soil-polluted is becoming increasingly serious.At present,there are many ways to control it,among which the mitigation effect of silicon on crop cadmium poisoning has been widely recognized by scholars both at home and abroad.The predecessors studied the use of silicon-containing materials are mostly alkaline substances,and contains associated ions,and pH and concomitant ions are also important factors affecting cadmium activity,then silicon-containing materials on the mitigation of crop cadmium is to change the soil pH and associated ions cause,or the role of silicon itself is difficult to determine.Therefore,based on the elimination of pH and concomitant ions,the effect of silicon application on the stress and cell structure,cadmium uptake and distribution,and soil desorption and desorption of cadmium were studied by means of indoor analysis and bioassay,in order to clarify the response of cadmium to different cadmium and the mechanism of silicon to inhibit the accumulation of cadmium in rice under the condition of silicon application.the conclusions are as follows:1.The effect of silicon on the membrane lipid peroxidation was higher than that of"Liaojing 9" under the same conditions,and the content of lipid in the membrane was"Liao Xing 19" by affecting the activity of antioxidant enzymes and the content of free proline.The structure of the leaves increased gradually,and the arrangement of chloroplast was gradually neat and clear,and the osmanthus particles became smaller and smaller.The number of mitochondria increased gradually and the dissolution of the two layers was alleviated.2.The application of silicon to cadmium in the roots of rice,reducing the transport to the ground,effectively alleviate the toxicity of cadmium on rice,increase rice biomass,increase rice yield,reduce cadmium content in rice.Compared with the single cadmium treatment,the difference of cadmium content between two kinds of rice unpolished rice was significantly decreased by applying silicon treatment(P<0.01).Under the same conditions,"Liaoxing 19" brown rice,stem and leaf transfer enrichment capacity is greater than "Liao Jing 9".3.The effect of silicon can promote the adsorption of cadmium and inhibit the desorption of cadmium in the soil.The effect increases with the increase of the amount of silicon.The silicon can also reduce the acid extractable state and reduce the cadmium content in the soil.In summary,silicon effectively alleviates the toxicity of cadmium to rice,increasing rice yield and reducing cadmium content in rice.When the levels silicon are 100 and 150 mg/kg,the content of cadmium in "Liaojing 9" reaches the national standard;Application of silicon to promote the adsorption of cadmium on the soil,exacerbate the hysteresis effect of desorption,the cadmium in the soil to the invalid form of transformation.Therefore,in the lower cadmium-polluted areas,the cultivation of cadmium-rich rice varieties,with the application of silicon fertilizer,can achieve cadmium contaminated soil remediation and safe use.