Gibberllin And Amine Fresh Lipid Enhance The Remediation Of Cd Contaminated Soil By Ryegrass

As compared with traditional technologies(eg:physical and chemical repairment),Phytoremediation technology has the advantages of low cost,high maneuverability and no damage to soil structure in practical application.Increasing the extraction of heavy metals by adding plant growth regulator is a better measure to improve the remediation efficiency of contaminated soil.In this paper,the effects of GA3 and DA-6 on the efficiency of Cd extraction in ryegrass were studied,and the effects of ryegrass on Cd detoxification under various conditions were fully discussed on the basis of in-depth analysis of the subcell and chemical morphological distribution of Cd in ryegrass.By soil culture experiment,Cd(NO3)2 was added into the soil to form contaminated soil with exogenous concentrations up to Omg/kg,25mg/kg,50mg/kg and lOOmg/kg.GA3 or DA-6 concentrations up to 1 ?M,10?M and 100 ?M respectively were sprayed on the leaf surface.The main research results are as follows:(1)Spraying plant growth regulators GA3 and DA-6 could both increase root length and chlorophyll content in the aboveground part of ryegrass,strengthen photosynthesis of plants and increase ryegrass biomass(P<0.05).Both GA3 and DA-6 can significantly increase the antioxidant enzyme activity of ryegrass and reduce the content of MDA.(2)Compared with the control,GA3 and DA-6 are able to enhance the ability of perennial ryegrass transshipment Cd in different degrees and extraction efficiency of Cd,the Cd concentration respectively 0 mg/kg and 25 mg/kg,50 mg/kg and 100 mg/kg,foliar spray of GA3 and DA-6 make ryegrass on Cd transfer factor(TF)by 0.04?2.5,0.1?0.7,and 0.5?1.1,0.6?1.7 times,to improve the efficiency of unit mass of lolium multiflorum extract Cd by 0.5?5.1,0.4?1.7,and 0.6?2.3,0.7?2.9 times.Under the conditions of this experiment,1 mol DA-6 had the best promotion effect,and the transport coefficient(TF)was 3.5,1.7,2.2,2.7 times of the control at the concentrations of 0mg/kg,25 mg/kg,50 mg/kg,and 100mg/kg,and the extraction efficiency was 6.1,2.7,3.3,and 3.9 times of the control.The results showed that leaf spray GA3 and DA-6 could strengthen the remediation of Cd contaminated soil by ryegrass.(3)According to the distribution of Cd subcells in the ground part of ryegrass,ryegrass detoxifies Cd by sedimentation of cell wall and ventrification of vacuolar area.By adding 10 ?M GA3 alone or 1 ?M DA-6,can promote the cell wall deposition of perennial ryegrass on Cd and vacuole area,greatly decreased organelles components in Cd concentrations(P<0.05),so that the Cd to effectively alleviate the harm of plant organelles,effectively improve the resistance of the plants,plant biomass(P<0.05)significantly enhanced.However,the addition of 100?M DA-6 alone increased the concentration of Cd in soluble components,leading to increased Cd toxicity to ryegrass and inhibiting plant growth(P<0.05).(4)The chemical forms of Cd distributed on the ground of ryegrass are three types:pectinate;protein binding or sorption(FNaCl);heavy metal phosphate(FHAc)insoluble in water.As FE,Fw,and FNaCl are highly mobile,they are seriously harmful to plants.The present study showed that the addition of 10 ?M GA3 or 1 ?M DA-6 decreased the mobility of Cd and alleviated the damage of Cd to ryegrass.