轮叶狐尾藻对水体重金属铅污染的耐性研究

Study on Tolerance of Myriophyllum verticillatum Linn.of Heavy Metal Lead Pollution

以狐尾藻(Myriophyllum verticillatum)为试验材料,采用液体培养法,研究了不同浓度Pb尾矿液单一胁迫下对其幼苗生长及生理指标的影响,以期为今后在探讨狐尾藻对Pb耐性机理方面提供参考依据和实践指导。结果表明:随着Pb尾矿渗出液单位浓度的升高,狐尾藻幼苗的株高和根长以及干质量整体呈不断下降趋势,其中,在100%Pb尾矿液处理下地下部的干质量较对照下降显著(P<0.05)。此时,地上部干质量较对照也呈下降趋势,但整体幅度不大,说明狐尾藻幼苗的生长整体受到明显抑制;随着Pb尾矿渗出液单位浓度的升高,幼苗中光合色素含量逐渐下降且整体均低于对照。在纯Pb尾矿液处理条件下,Chla、Chlb和Car的含量比对照下降了14.6%、29.6%和23.2%;所有处理中幼苗地下及地上部相对电导率与Pb尾矿液浓度成正比且均高于对照。各个处理的地上及地下部Pro含量随着Pb尾矿液浓度增高整体呈上升趋势。其地上和地下部的AsA含量和GSH含量变化呈低浓度上升,高浓度下降的趋势。在25%Pb胁迫处理下,幼苗中AsA含量在地上和地下部均达到最高,与对照相比差异明显(P<0.05),较对照增加了93.5%和89.8%。而地上和地下部GSH含量较对照增加了35.7%、4.36%。数据表明,狐尾藻对Pb胁迫下的环境有一定的抗性,可被用于Pb污染环境的生态修复。

The research created a liquid cultivation method to study Myriophyllum verticillatum as an experimental material.The growth and physiological indexes of seedlings was affected by the different concentration of Pb tailings in the stressed environment.The results showed that with the increasing of Pb tailing leaching liquid unit of concentration,the height,root length and dry weight of Myriophyllumseedling showed an overall declining trend.The dry weight of tailings was decreased significantly（P〈0.05）in the underground part of the 100% Pb solution,while the dry quality of aboveground also showed a downward trend than the control.But the descend range was less than the underground part growth and the overall Myriophyllumseedlings was significantly inhibited.With the increasing of Pb tailing leaching liquid unit of concentration,including light and Myriophyllum seedlings,the content of pigment（chlorophyll a,chlorophyll b and carotenoid content was decreased）was generally lower than that of the control.Chlorophyll a,b and carrots in the process of pure Pb tailing liquid condition made the content of carotene was decreased by 14.6% than CK,29.6% and 23.2%.The underground and aboveground of seedling Myriophyllum relative conductivity and Pb tailing liquid were proportional to the concentration of which was higher than the control.With the increasing of the concentration of Pb tailings,the treatment of the aboveground and underground part of proline（Pro）content was showed the overall upward trend.The aboveground and underground parts（AsA）and the content of glutathione（GSH）changes were showed low concentration and high concentration decreased.In the 75% NH and 25% Pb stress condition,the content of AsA in the aboveground and underground parts of Myriophyllum＇s seedlings were the highest,compared with the control group significantly（P〈0.05）,increased 93.5% and 89.8%.However,the aboveground and underground parts of GSH＇s content increased by 35.7% and 4.36%.The experimental data showed that spicatum could be used for ecological restoration of Pb contaminated environment as long as Pb stressed environment to a certain degree.