Veronica becabonga L. as a hyperaccumulatorplant for cadmium

Abstract

Heavy metal pollution of water is a major environmental problem facing the modem world.The major objective of this research was to evaluate the potential of water-speedwell plant,Veronica becabonga L. to uptake and accumulate heavy metal cadmium under greenhouseconditions, Veronica becabonga L., were cultured in 3% Hoagland's nutrient medium, whichwas supplemented with 0, 25, 50,100, 200, 300 mg/I of Cd(NO3)2 4H2O over one weektreatment period. Plants were harvested at the end of this period and heavy metals from theentire shoot tissue was extracted using the closed Teflon vessel method and metal content inthe extract was estimated using a Flame atomic absorption spectrophotometry. The resultsshowed that the uptake and accumulation of Cd in V becabonga L. showed significantincrease when metal concentration was increased. The highest amount of Cd accumulationwas detected at 100mg/I Cd(NO3)24H2O in the culture solution that was 20660.3 mg/kg DWof shoots. The linear pattern of uptake suggest the involvement of both active and passivetransport mechanisms for Cd uptake, Finally, since the high concentrations cadmiumaccumulation in shoots of plants has far exceeded 0.01% DW V becabonga L. is ahyperaccumulator plant for this metal and has potential for phytoremediation of watercontaminated with cadmium,