Heavy metal tolerance of weed species and their accumulations by phytoextraction

Abstract

>The ability of the invasive weed species Parthenium hysterophorus L. for the accumulation of the heavy metal Cd was studied in a greenhouse experiment. This study aimed at identifying a metal tolerant species from natural vegetation and to assess the phytoextraction potential of the plant. To compare metal concentration in the aboveground biomass to those in roots and in soils,To study their effect on growth and comparison with metal amended soils treated with EDTA. The Cd accumulated by test species was increased significantly after 0.1g / Kg of EDTA was added to the medium. An increase in metal uptake with increase in test concentrations during the early stages and developmental stages was observed which indicates the plant's tolerance to the heavy metal. But a decrease in metal uptake with the maturity of the plant was observed. This indicates that the plant's ability for the metal uptake reduces with time i.e. with maturity. The BCF's of the shoots and roots and TF's being >1 shows the validity of the weeds species for hyperaccumulation of the metal Cd. This is due to the plant's capability to uptake the metal and its tolerance capacity for the heavy metal Cd. Hence, it can be a promising species for phytoextracton of heavy metals and remediation of contaminated soils which is economical and ecofriendly.