Comparative Assessment of Cadmium, Chromium Resistance Capacity of Amaranthus viridis, Trianthema portulacastrum，Alternanthera philoxeroides Collected from Contaminated Site and Assessment of Phytoremedial Potential

摘要

Among heavy metals cadmium and chromium pollution of soil is an alarming environmental issue as these metals are released in the atmosphere by anthropogenic activity. Their various use in industry, agriculture and domestic applications have led to their accumulation in the environment. Being biologically non essential both these metals are phytotoxic and injurious to animal also. Plants with greater capacity of metal accumulation are potential candidate of phytoremediation for cleanup of heavy metal contaminated soil. As, identification of metal tolerant native plant is prerequisite for phytoremediation, field studies were conducted to different Cd, Cr contaminated sites to assess metal tolerance of various plants. Comparative study was done with three different species (Amaranthus viridis, Trianthema portulacastrum, Alternanthera philoxeroides), collected from metal contaminated sites of Kolkata. Metal concentration of these plants and various biochemical parameters (lipid peroxidation, proline, non protein thiol content, SOD, glutathione reductase activity) were studied to assess metal detoxification capacity. Soil properties were studied to determine metal bioavailability. Alligator weed (Alternanthera philoxeroides), was found to be most abundant with considerable metal accumulation capacity and biochemical defences in comparison to others plants. To assess phytoremediation potential, this plant was potted in laboratory condition with artificial treatment of different concentration of Cd, Cr and metal uptake was estimated. Phytoextraction capacity was estimated also.