黄葛树对土壤铅、镉污染耐受性的研究

以黄葛树为实验材料,通过盆栽实验研究梯度浓度土壤外源铅胁迫(0,250,500,900mg/kg)、外源镉胁迫(0,5,10,20,30mg/kg)对黄葛树形态生长、生理生化特征的影响,旨在综合评价黄葛树对土壤铅、镉污染的适应性,为黄葛树对土壤铅、镉污染的修复潜力研究提供基础.结果表明:250mg/kg铅污染胁迫与5mg/kg镉胁迫对黄葛树株高、地径净生长量、可溶性糖质量分数、SOD活性均无显著影响;250,500mg/kg铅污染与5,10mg/kg镉污染显著增加了黄葛树叶片叶绿素质量比;实验组MDA浓度均显著高于对照;实验设置污染浓度内,900mg/kg铅胁迫与30mg/kg镉胁迫对黄葛树生长的抑制作用最强.研究说明:土壤铅、镉污染对黄葛树生长的影响具有"低促高抑"的特点,500,10mg/kg是铅、镉胁迫对黄葛树生长产生抑制作用的临界质量比,此临界质量比与土壤污染标准相比较可得黄葛树对镉胁迫的耐受性更强.

On Tolerance of Ficus Virens Aiton in Soil Contaminated by Pb and Cd

The aim of this study is to evaluate the tolerance of Ficus virens Aiton to soil contamination by lead (Pb) and cadmium (Cd) in pot experiment, in order to provide the basis for the research of the potential for phytoremediation of Pb and Cd pollution. With Ficus virens Aiton as the experimental material, and contaminated soil was treated by Pb and Cd in five concentrations respectively. The plant behavior was assessed by the changes of its physiological activity. Results show that when the concentrations of Pb and Cd was 250, 5mg/kg, the plant height, net diameter, soluble sugar content and SOD activity of Ficus virens Aiton had no significant effect. The stress concentrations of Pb and Cd which was 250, 500 and 5,10 mg/kg increased photosynthetic pigment of Ficus virens Aiton. And the malondialdehyde content of experimental group was all higher than control. The damage to the Ficus virens Aiton could reach up to their maximum when concentrations of Pb and Cd was 900, 30mg/kg. It is indicated that the critical concentrations of Pb and Cd inhibited the growth of Ficus virens Aiton was 500, 10mg/kg, and low stress could promote the growth of Ficus virens Aiton. Compared with Pb stress, the tolerance to Cd was better.