Cadmium tolerance and its enhanced accumulation potential of Arundo donax by EDTA

Abstract

Aim: Cadmium accumulation in soil and water is becoming a major environmental problem due to high toxicity of Cd and its high mobility from soil to crops and further to food chain. In order to remediation its bioavailability in soil, tolerance ability of potential plant are major concern at metalliferous sites. The present investigation was, thus, carried out with an objective to test the tolerance ability of Arundo donax (Giant reed) to cadmium with orwithout EDTA. Methodology: The present study was conducted during 2013 to elucidate the growth response of Arundo irrigated with different levels of cadmium (0,100,200,400,800 and 1200 mg I-1). In addition, to enhance the phytoaccumulation potential of cadmium, ethylene diaminetetraacetate (EDTA) aqueous solution at three rates (0,3 and 6 mg I-1) was applied to the plant. Results: The results indicated that Arundo donax tolerated Cd upto 400 mg I-1 without showing any adverse effect in terms of plant height, number of tillers, leaf area and total chlorophyll. The plant accumulated cadmium from spiked medium to shoot and root with bioconcentration factor (BC) of 1.44 and 1.96, respectively, at 200 mg I-1 Cd exposure. EDTA significantly enhanced 12.8% dry weight of shoot and enhanced 2-3 times cadmium accumulation in root as compared to control (No EDTA). At elevated cadmium concentration (400 mg I-1), the BC factorof 7.74 in rootand 0.89 in shoot was recorded under EDTA application of 3 mg I-1. Except root length, no adverse effect of EDTA was observed on plant growth. Interpretation: Arundo donax is a perennial weedy plant which grows at moist places throughout the year in India, Giant reed tolerated high concentration of cadmium, and in the presence of EDTA enhanced Cd uptake was 2-3 times in its root and translocation to shoot part also Having high tolerance ability, combination with optimum dose of EDTA (3 mg I-1) Arundo has implications for phytoremediation of less bio-available cadmium contaminated sites.