Comparative tolerance and phytostabilization potential of Conocarpus erectus and Eucalyptus camaldulensis grown in cadmium contaminated soil

Abstract

Phytoremediation is the most promising approach for the remediation of Cd contaminated soils. In the present study, Cd tolerance and phytoremediation potential of Conocarpus erectus and Eucalyptus camaldulensis, was evaluated in a pot experiment for a growth period of 6 months. Two-month-old plants of uniform size were transplanted in Cd- contaminated soil (0, 5, 10 and 15 mg kg-1 ), and their growth attributes, chlorophyll contents, root and shoot Cd concentration, bioconcentration factor (BCF) and translocation factor (TF) were determined. With increasing soil Cd levels, shoot and root biomass, leaf water and chlorophyll contents (chl a, chl b and total chl) of E. camaldulensis were decreased more than C. erectus. Shoot and root Cd concentrations as well as Cd uptake were more in C. erectus than E. camaldulensis. The TF was less than one for both plant species, while BCF was more than one. It is concluded that due to relatively higher Cd tolerance and greater capacity to retain higher concentration of Cd in roots, C. erectus is a better species than E. camaldulensis for phytostabilization of Cd contaminated soils.