Comparative assessment of Indian mustard (Brassica juncea L.) genotypes for phytoremediation of Cd and Pb contaminated soils

Abstract

Heavy metal removal by phytoremediation bears a great potential to decontaminate soils and Brassica juncea L. (Indian mustard) seems to be a possible candidate species for this purpose. A field experiment was conducted to compare the efficiency of eighty Indian mustard cultivars for phytoextraction of cadmium (Cd) and lead (Pb) from bimetal contaminated soil. Our results indicated that total Cd and Pb concentrations in the shoots and roots were in the range of 2.43 ± 0.00 to 0.31 ± 0.02 mg/kg and 2.94 ± 0.05 to 0.44 ± 0.03 mg/kg and 5.33 ± 0.76 to 0.47 ± 0.20 mg/kg and 3.78 ± 0.06 to 0.16 ± 0.08 mg/kg. Significant differences based on the translocation factors indicated that root-to-shoot transfer is higher for Pb (3.87 ± 0.12 to 0.48 ± 0.03) than Cd (3.38 ± 0.05 to 0.22 ± 0.01). Furthermore, significant correlations between dry weights, Cd and Pb concentrations and uptake in both shoots and roots were observed, but translocation factor showed a negative correlation with roots, but not in shoots. Among 80 genotypes of Indian mustard IM-25, IM-13 and IM-65 for Cd and IM-79, IM-24 and IM-32 for Pb seems to perform well for phytoextraction. The results of the field experiment suggest that certain Brassica juncea L. cultivars are suitable for removal of Cd and Pb in low to moderately contaminated soils.