铅、锌、镉胁迫对多年生黑麦草生长及生理生化特性的影响

为了解多年生黑麦草对Pb、Zn、Cd的耐性和土壤重金属污染的修复潜力,采用砂培法研究铅(Pb)、锌(Zn)、镉(Cd)对多年生黑麦草生长发育及生理生化特性的影响.Pb2+设0(CK)、500(Pb500)、l 000(Pb1000)、2 000 mg?kg-1(Pb2000)四个处理,Zn2+设0(CK)、500(Zn...

Effects of Pb2+, Zn2+ and Cd2+ on Growth,Physiological and Biochemical Characteristics of Perennial Ryegrass

In order to understand the tolerance of perennial ryegrass to Pb, Zn and Cd and the remediation potential of heavy metal pollution in soil, sand culture method was used to study the effects of plumbum (Pb), zinc (Zn) and cadmium (Cd) on the growth, physiological and biochemical characteristics of perennial ryegrass.Pb²⁺ treatments with0 (CK), 500 (Pb₅₀₀), 1 000 (Pb_{1 000}) and 2 000 mg·kg^-1 (Pb_{2 000}) concentrations,Zn²⁺ treatments with0 (CK), 500 (Zn₅₀₀), 1 000 (Zn_{1 000}) and 2 000 mg·kg^-1 (Zn_{2 000})concentrations,Cd ²⁺ treatments with0 (CK), 10 (Cd₁₀), 20 (Cd₂₀) and 50 mg·kg^-1 (Cd₅₀) concentrations were set up. The morphological characteristics, chlorophyll content, antioxidant enzymes activities, membrane lipid peroxidation product content and osmotic adjustment substances contents of perennial ryegrass under different concentrations ofPb²⁺,Zn²⁺ andCd ²⁺ were determined, and these indexes were comprehensively evaluated by Fuzzy membership function method. The results showed that: ①Pb²⁺,Zn²⁺ andCd ²⁺ stress significantly inhibited the growth of perennial ryegrass, andPb_{2 000},Zn_{2 000} andCd₅₀ treatments had the most significant inhibition on biomass, tiller number and root growth of perennial ryegrass. ② Under the stress ofPb²⁺,Zn²⁺ andCd ²⁺, perennial ryegrass slowed down the damage to plants by increasing osmotic adjustment substances and antioxidant enzymes activities of plants. The contents of superoxide dismutase and peroxidase were increased first and then decreased with the increase ofPb²⁺,Zn²⁺ andCd ²⁺ concentrations. Malondialdehyde and proline contents were increased with the increase ofPb²⁺,Zn²⁺ andCd ²⁺ concentrations. With the increase ofPb²⁺,Zn²⁺ andCd ²⁺ concentrations, the soluble sugar contents of Pb500 and Cd10 treatments were decreased, while that of Zn500 treatment were increased. ③ Perennial ryegrass had certain tolerance toPb²⁺,Zn²⁺ andCd ²⁺, and the stress resistance of plants in all treatments showed as following:Zn₅₀₀ > CK >Zn_{1 000}> Cd₁₀> Pb₅₀₀ >Zn_{2 000}> Cd₂₀ >Pb_{1 000} >Pb_{2 000}> Cd₅₀. The present research provided theoretical and data support for ecological restoration.