铜对伴矿景天生长及锌镉吸收性的影响

利用植物生长室水培试验和温室土培盆栽试验相结合,研究了Cu对Zn、Cd超积累植物伴矿景天生长及Zn、Cd吸收性的影响。水培试验结果显示,0.31～50μmol/L Cu处理14天对伴矿景天生长及对Zn、Cd吸收性没有显著影响;但100μmol/L Cu处理显著抑制植物生长,降低地上部Zn、Cd及根中Cd浓度,对根中Zn浓度变化没有显著影响。盆栽试验结果发现,在土壤Cu仅为3.61 mg/kg时伴矿景天生长不良,外加Cu显著促进其生长并随Cu浓度升高效应增加;但施用3 mmol/kgEDDS和再次外加250 mg/kg Cu处理使伴矿景天因体内Cu积累量过高而导致明显毒害,地上部Cu最高达1 068 mg/kg。可见低量Cu处理可促进伴矿景天生长,利于植物对土壤Zn、Cd的吸取修复,但土壤中Cu浓度过高将抑制Zn、Cd超积累植物的生长,降低其Zn、Cd吸收能力,在利用该Zn、Cd超积累植物修复高Cu的Zn和Cd污染土壤时应采取适当措施降低Cu毒害效应。

Effects of copper on growth and zinc and cadmium accumulation of Sedum plumbizincicola

Growth chamber hydroponics culture and glass house pot experiment were conducted to study the effects of copper on the growth of Sedum plumbizincicola plant and its accumulations of Zn and Cd.The results from the hydroponics culture showed that there was no significant difference on the growth and Zn and Cd concentrations of Sedum plant among the treatments of low solution Cu concentrations(0.31-50 μmol/L),but 100 μmol/L solution Cu inhibited plant growth and Cd and Zn accumulations in plant shoot.The glass house pot experiment results showed that sedum plant grew slowly in soil at low Cu(3.61 mg/kg) concentration,however,the addition of Cu promoted its growth.The application of 3 mmol/kg EDDS and 250 mg/kg Cu led the greater accumulation of Cu in plant,with the highest Cu concentration of 1 068 mg/kg,which may be responsible for plant injury and leaves fallen down.These results showed that low concentration of Cu benefits the plant growth and the phytoextraction of Zn and Cd from contaminated soil,but high soil Cu concentration inhibits plant growth and metals uptake.Therefore,more attentions should be paid on plant Cu toxicity when using Sedum plumbizincicola to remediate Cd and/or Zn contaminated soil with high concentration of Cu.