锌镉交互作用对伴矿景天锌镉吸收性的影响

采用水培试验、不同Zn、Cd污染程度农田土壤结合外加Zn、Cd基础上的土培盆栽法,研究了不同Zn、Cd浓度交互作用对伴矿景天生长及Zn、Cd吸收和分布的影响.水培试验结果表明,增加溶液中Zn和Cd浓度,伴矿景天各组织中Zn和Cd浓度显著增加,但两个高浓度处理间没有显著差异;Zn在伴矿景天体内呈不均匀分布且与水培溶液中Zn和Cd浓度有关,当溶液中Zn浓度＞Cd浓度时,表现为新叶＞成熟叶＞其他部位＞＞根,反之则为成熟叶＞其他部位＞新叶＞＞根;而Cd在伴矿景天不同部位的分布没有一致的规律性;Zn、Cd交互作用主要体现在伴矿景天新叶上:在溶液中外加Cd时,Zn对伴矿景天新叶中Cd浓度具有“低促高抑”效应,而Cd处理对新叶中Zn浓度具有拮抗效应.土培试验也表明,添加Zn显著促进伴矿景天对土壤中Cd的吸收,外加Cd对伴矿景天Zn吸收具有拮抗效应;但无论Zn或Cd,外加量过大均会显著抑制伴矿景天的生长,降低修复效率.

Interaction of Zn and Cd on Heavy Metal Phytoextraction Efficiency of Sedum plumbizincicola

Growth chamber hydroponics culture and glass house pot experiment with Zn and Cd polluted agricultural soil were used to study the interaction effects of different Zn and Cd concentrations on Sedum plumbizicola growth, Zn and Cd uptake and distribution in plant. Hydroponics culture results showed that Zn and Cd concentrations in all part of plant increased significantly with Zn and Cd concentration in hydroponics solution, but there were no significant differences between the two high concentration treatments; the uneven Zn distribution was found in the plant and had relationship with Zn and Cd concentration in the hydroponic solution, for the concentration of Zn > Cd in the solution, Zn concentrations in plant were as following: the young leaves > mature leaves> the other parts >> roots, on the contrary, the order showed as: mature leaves > other parts > young leaves >> roots; Cd distribution in the plant different parts had no consistent regularity; the interaction of Cd and Zn is mainly reflected on the young leaves: when the solution was presented with Cd, low Zn concentration in solution had synergy effects on Cd concentration in young leaves, and high Zn had antagonistic effect; Cd also had antagonistic effect on Zn concentration in young leaves. The soil pot experiment results also showed that the high Zn could promote plant Cd uptake, and Cd had antagonistic effect on the uptake of Zn. Extremely high Zn or Cd would significantly inhibit plant growth, and thus lower remediation efficiency.