铁锰复合污染对美洲商陆生物毒性及超积累特性的影响

Effect of Fe-Mn Combined Pollution on Biological Toxicity and Hyperaccumulation of Phytolacca americana

采用溶液培养法研究了铁(0,0.5,1 mmol/L)和锰(0,4,8 mmol/L)复合污染对美洲商陆发芽、胚根伸长抑制率及植株体内铁锰含量的影响。结果表明,不同浓度铁锰处理均抑制种子发芽和胚根伸长,当铁浓度为0.5 mmol/L时,随着锰浓度的升高抑制作用减弱,当铁浓度为1 mmol/L时种子发芽及胚根伸长受到明显抑制,添加锰不能起到缓解作用;铁浓度一定时,随着锰浓度的增加,植株根部铁含量明显下降,当锰浓度一定时,随着铁浓度的升高从根部向地上部转运的锰减少;相关分析和多元回归分析表明,美洲商陆体内各部分铁锰含量与锰处理浓度偏相关程度较高,均达极显著水平,尤以根部含量影响最为显著,其中锰处理浓度与植株内锰含量呈正相关,与铁含量呈负相关;美洲商陆在复合污染处理14 d后锰积累量高于7 d的积累量,且地上部锰积累量大于地下部,说明美洲商陆适宜在一定浓度范围内的铁锰复合污染进行植物修复。

In this research,seed germination,radicle elongation rate and hyperaccumulation of Phytolacca americana to iron（Fe） and manganese（Mn） combined pollution were studied,and the nutrient solution was treated by the interaction of Fe（0,0.5,1 mmol/L） and Mn（0,4,8 mmol/L）.The results showed that the addition of Fe and Mn inhibited the seed germination and radicle elongation,when the Fe2＋ concentration is 0.5 mmol/L,the inhibition effect decreased with Mn2＋ concentrations increase,but the seed germination and radicle elongation were seriously inhibited under 1 mmol/L concentration of Fe2＋,and the Fe2＋ toxity was allieved after adding Mn;When the Fe2＋ concentration was certain,Fe2＋ content of root decreased significantly,when the Mn concentration is certain,with the increase of Fe2＋ concentration,Mn content of shoot reduced;Correlation analysis and multiple polynomial regression analysis further revealed that there were significant relationships between Mn concentration and Fe,Mn content of plant,especially in content of the root.Mn concentration was positively correlated with Mn content,but negatively correlated with Fe;Phytolacca americana have more accumulation of Mn in the composite 14-days than 7 days under pollution conditions,and Mn accumulation of shoot is always greater than root,which indicated that Phytolacca americana can be made use of Fe-Mn combined pollution within suitable concentration for phytoremediation.