Study On The Ecological Response Of Carex Brevicuspis Under The Stress Of Cd

Cadmium(Cd)is one of the main heavy metal pollutants in soil and has the characteristics of strong biotoxicity and high mobility.After accumulating a certain amount in the plant,it will affect the material accumulation and energy metabolism of the plant,which will affect the normal growth of the plant and even affect human health through the food chain.Therefore,the control of cadmium pollution is an important task at present.Carex brevicuspis is a perennial herb with large biomass and strong tolerance.It is a widely distributed plant in the Dongting Lake area and plays an important role in soil and water conservation in the area.This study uses pure mesoporous silica(MSN,Mesoporous silica nanoparticles)and mesoporous silica-calcium phosphate composite nanoparticles(MS-CP,mesoporous silica-calceum phoxate)are Silicon sources,short-pointed Carex is a material,and potted plants and hydroponics are carried out under cadmium concentration gradients.The phenotype and physiological characteristics of the plant under Silicon addition and non-Silicon addition were compared.The purpose was to reveal the response mechanism of the plant to cadmium stress.The findings are as follows:(1)MS-CP has a high specific surface area(314.56 m2/g),large pore capacity(1.21 CM3/g)and double aperture distribution(3.82 nm and 12.40 nm).MS-CP has a Cd2 + in solution High performance of adsorption.The removal rate of MS-CP to Cd2 + increases with the increase of adsorption time and solution temperature,and decreases with the increase of initial Cd2 + concentration.When the initial Cd2 + temperature is 100-350 mg/L,The removal rate of MS-CP to Cd2 + in solution can be reached 100%by increasing the adsorption time and/or solution temperature.For the initial Cd2 + concentration of 100 mg/L,The removal rate can reach 100%within 0.5 H.When the adsorption time is maintained,the higher the initial Cd2+concentration,the higher the temperature required for the removal rate to reach 100%.In addition,under the same conditions,The solution with pH = 5 is the most favorable for Cd2+ adsorption to the MS-CP surface.(2)Pot experiments were carried out without Silicon treatment and the results showed that with the increase of Cd2 + concentration,The leaf length,leaf width,root length,root fresh weight and leaf fresh weight of Brassica edulis gradually increased.When the Cd2 + concentration was gradually increased by 300 mg/L,350 mg/L,450 mg/L,and 500 mg/L,The leaf length,leaf width,root length,root weight,and Yezhong were gradually reduced.With the increase of Cd2 + concentration,the root dry weight and leaf dry weight decreased.The number of spikelets and the length of spikelets showed a tendency of first increasing and then decreasing.The Cd content of the upper part and the underground part showed an increasing trend.(3)Carrying out pot experiments without Silicon treatment,The results showed that the activity of chlorophyll,superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and proline in Cadmium was 0 mg/L,100 mg/L and 200 mg/L under cadmium stress.The content gradually increased,Protect the plant.When Cd is treated with 300 mg/L,350 mg/L,450 mg/L,and 500 mg/L,The activity of chlorophyll,superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and proline in two species of Carexa was significantly inhibited.The content of MDA and soluble protein in the body will increase with the increase of cadmium concentration,showing different degrees of increase.(4)Water culture experiments conducted under Silicon treatment conditions showed that when the cadmium concentration reached 300 mg/L,the growth trend of the leaves of Brassica edulis was significantly inhibited and the length was smaller than that of the control group.However,the inhibition effect on the long growth of the added MS-CP group was less than that of MSN group and non-Silicon group.The cadmium concentration reached a minimum of 500 mg/L and the length was 51.3%smaller than that of the control group.The results show that the Silicon treatment obviously relieves the inhibition of cadmium on the growth of Carex Brassica,and improves the leaf length,plant height,root length and dry weight under cadmium stress.