Potential of Medicago sativa for uptake of cadmium from contaminated environment

Cadmium is associated with industrial processes such as metal plating and the production of nickel-cadmium batteries, pigments, plastics and other synthetics. Cadmium is a potential environmental hazard. A cost effective technologies are needed to remove cadmium from the contaminated soil-water environment. Phytoremediation is a novel, cost effective and eco-friendly 'green' remediation technology for environmental cleanup. In the present research study the uptake of cadmium by Medicago saliva (alfalfa, var. Col) has been studied under in vitro culture (aseptic) conditions. Plants initially grown in liquid media containing Murashige & Skoog medium were transferred to Steinberg solution spiked with cadmium as Cd (NO3)(2), 4H(2)O at concentration 0, 5, 10, 20 and 50 mu g ml(-1). The experiment was continued for a period of 21 days till complete metal uptake takes place. It has been observed that the growth of alfalfa plants was affected at higher concentration i.e. at 20 and 50 mu g ml(-1); whereas the lower concentration of cadmium was uptaken without any effects on growth of plant. The cadmium content in plant tissues was quantified using Atomic Absorption Spectroscopy. The result shows that most of the cadmium upto 12360 mu g gm(-1) was located in roots, while 1920 jig gm-1 was translocated to shoots when exposed to 50 mu g ml(-1) concentration of cadmium. The phytoremediation of cadmium using alfalfa plant in hydroponic solution shows that, during the period of the experiment (i.e. 21 days), the plant was found to have potential to uptake 80-85% of cadmium.