Growth Responses of Rorippa globosa and Its Accumulation Characteristics of Cd and As under the Cd-As Combined Pollution
镉超富集植物球果菜对镉-砷复合污染的反应及其吸收积累特征

Rorippa globosa has been identified as a new Cd-hyperaccumulating plant species. In the present study, growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under the condition of Cd-As combined pollution. The results showed that Cd and As had an antagonistic effect on enhancing the growth of the plants and Cd uptake and accumulation under the low concentration Cd and As treatments. When Cd and As concentrations were 10 mg/kg and 50 mg/kg, the highest height of the plants and the dry weight of shoots were up to 35.9 cm and 2.2 g/pot, respectively; and the accumulation of Cd in the leaves under the combined pollution was higher than that at the same level under single Cd pollution. However, there were synergic adverse effects on plant growth and Cd uptake under the high concentration Cd and As combined pollution. Meanwhile the accumulation of As in the roots was higher than that in the shoots, the translocation factor < or = 0.3 and the bioaccumulation factor < or = 0.6, which showed that Rorippa globosa had an excluding effect on As uptake. These results confirmed that Rorippa globosa had the strong tolerance ability to the Cd-As combined pollution, and the potential applied to phytoremediation of contaminated soil by Cd and As.