Copper (Cu) tolerance and accumulation potential in four native plant species: a comparative study for effective phytoextraction technique

Abstract

Phytoextraction involved the use of plants in rapid, efficient, less expensive, and environment friendly removal of toxic metals from contaminated soil. For this study, a pot experiment was conducted and plant species: Abelmoschus esculentus, Avena sativa, Guizotia abyssinica, and Glycine max were subjected to six copper concentrations i.e., 25, 50, 100, 150, 200, and 300 mg Cu kg−1 for the investigation of Cu phytotoxicity, tolerance, and accumulation for 12 weeks under green house. Soil without spike were taken as control. After 12 weeks of experiment, Cu toxicity on growth and chlorophyll contents were determined. Among four plant species, only A. sativa, C. tetragonoloba and S. indicum seeds were germinated at 300 mg Cu kg−1. The growth parameters were significantly (p < 0.05) reduced under high Cu stress (from 25 to 100 mg Cu kg−1) in G. abyssinica and G. max. The chlorophyll content found maximum at 25 mg Cu kg−1 in all plant species as compared to control. Significantly, high Cu accumulation was found in roots and shoots of A. sativa. The highest values of bioconcentration factor, bioaccumulation coefficient, translocation factor (all greater than 1), phytoremediation ratios, and accumulation with high tolerance suggested that A. sativa was a suitable plant for effective Cu phytoextraction.

Keywords

• soil contamination
• phytotoxicity
• bioconcentration
• bioaccumulation
• phytoremediation ratio