Pb、Cd及其复合污染对紫茎泽兰生长及吸收富集特征的影响

外来植物紫茎泽兰（Eupatorium adenophorum）入侵我国西南地区并造成了严重的生态灾难,通过研究Pb、Cd及其复合污染对紫茎泽兰生长及吸收富集特征的影响,有助于从生态学角度为紫茎泽兰的综合防控提供依据。采用模拟Pb、Cd污染土壤培养法研究了不同浓度Pb、Cd及其复合污染作用下紫茎泽兰的生长响应及重金属吸收、富集和迁移特征变化。结果表明：低浓度的Pb、Cd对紫茎泽兰的生长有促进作用,高浓度则表现出一定的抑制作用,生物量,株高,根长均明显减少。紫茎泽兰体内Pb、Cd吸收量与污染土壤具有良好的相关性,随处理浓度增加明显增大,极端浓度Pb、Cd胁迫下紫茎泽兰各器官Pb、Cd积累量与对照相比显著增加,1000 mg·kg-1处理时紫茎泽兰根、茎、叶的Pb质量分数均分别高达603.69、568.31、598.85 mg·kg-1;100 mg·kg-1 Cd处理时其根、茎、叶的Pb、Cd累积量依次为165.21、93.59、152.79 mg·kg-1。说明紫茎泽兰对Pb、Cd具有较好吸收累积及转运能力,可作为重金属污染地区的一种理想的修复植物。

Growth and absorption enrichment responses of Eupatorium Adenophorum Spreng to Lead,Cadmium and their combined stress

E. adenophorum Spreng is one of the worst invasive alien plants into China. It brings great harm to the ecological environment in the Southwest of China. A controlled pot-experiment cultivated withE. adenophorum was arranged with different treatments of lead and cadmium concentrations in field. Growth and absorption enrichment responses ofE. adenophorum Spreng to lead, cadmium and their combined stress were evaluated in order to provide integrate strategies ofE. adenophorum. A pot experiment was study to observe the growth responses, accumulation and transfer characteristics ofE. adenophorum in different concentrations of lead, cadmium. Results showed that there was a positive effect on the growth of E. adenophorum under low concentrations for both lead and cadmium but negative effect in high concentration, with the decreasing biomass,shorter plant height and root length. Lead and cadmium. Absorption content of E. adenophorum had a favorable correlation with contaminated soil, which increased significantly with the conbined treatment concentrations raising. lead and cadmium concentration of the roots, stems and leaves ofE. adenophorum was much higher in corresponding treatments. The lead content of roots, stems and leaves ofE. adenophorum were 603.69, 568.31 and 598.85 mg·kg-1, respectively, when the plants were treated with 1000 mg·kg-1 lead in soil. The cadmium contents in the roots, stems and leaves were 165.21, 93.59 and 152.79 mg·kg-1, respectively, under the 100 mg·kg-1 cadmium stress.E. adenophorum has good capacity of absorption, accumulation and transfer under heavy metals stress of lead and cadmium and it can, therefore, be used as ideal plant to repair composite pollution soil of heavy metals.