Tolerance Characteristics And Heavy Metal Accumulation In Aralia Elata Var.Inermis Under Cd,Pb And Zn Combind Pollution

Aralia elata var.inermis is a kind of important woody vegetables,which has high research value.Pot experiments,with 5 concentration gradient including single and combined stress of cadmium(0,1,5,10,20 mg/kg),lead(0,100,500,1000,1500 mg/kg)and zinc(0,100,500,1000,1500 mg/kg),were conducted to study physiological and biochemical response and heavy metal accumulation in Aralia elata var.inermis under single and combind pollution of Cd,Pb and Zn.Studying the Analysis of Aralia elata var.inermis against the resistance mechanism of heavy metal stress and the interaction mechanism between the Cd,Pb and Zn element,to provide scientific basis on revealing the mechanism of heavy metal combind stress,taking control of soil heavy metal pollution and ensuring the safety in production of agricultural products.The results are shown below.(1)Single and combined stress of Cd,Pb and Zn in Aralia elata var.inermis has obvious inhibitory effect on ger mination,Zn and Cd.And Cd showed higher toxicity than Zn on growth of Aralia elata var.inermis.Single or two kinds of heavy metal combind stress on bud length characterized by inhibition,and three kinds of heavy metal combind stress on bud length inhibition of Aralia elata var.inermis is the most obvious.(2)Soluble protein content in leaves of Aralia elata var.inermis was decreased with the increase of concentration of heavy metals under Cd+Zn or Pb+Zn stress,and the others showed a trend of reduce after the first rise.The soluble sugar content in the single stress was increased under single Zn stress,while the rest of the heavy metal treatment group on the influence of the soluble sugar content was promoted and turned to inhibition later.The effects of composite stress of Cd,Pb and Zn on reducing chlorophyll content effect is most obvious.(3)MDA content in leaves of Aralia elata var.inermis showed a trend of rise after the first reduce under single heavy metal stress,showing that low concentration of single heavy metal stress on the peroxidation damage in leaves is smaller.And combind stress showed a higher damage than single stress,Showed the synergy between the heavy metal elements.Cd,Pb and Zn of single stress can make the CAT activity,and Pb has a minimal impact on antioxidant enzymes activity.(4)The effect of Pb/Zn single stress on Cd accumulation in root of Aralia elata var.inermis is inhibition,while Pb can promote the absorption of Cd in the stem and leaf.Pb/Zn combind stress can promote accumulation of Cd in Aralia elata var.inermis under Cd pollution.Accumulation of order of heavy metal in Aralia elata var.inermis is root > stem >leaf.Pb concentrate in the roots of Aralia elata var.inermis,and a tiny amount accumulation was found in the leaf.Cd can promote Pb absorption in leaves of Aralia elata var.inermis,but it has inhibition effect on the accumulation in the roots and stems.Zn has inhibition effect on accumulation of Pb in stems and leaves.The addition of Zn inhibited the transfer of Pb from the root to the stem and leaf.It has the strongest effect in promoting the Pb absorption in roots under Cd/Zn combind stress.The inhibition was observed on Zn accumulation in the root,stem and leaf of Aralia elata var.inermis when adding Cd.The addition of Pb on Zn accumulation in the root,stem and leaf has a promoting effect.