Comparative analysis of tissue compartmentalized heavy metal uptake by common forage crop: A field experiment

Abstract

Heavy metal contamination of agricultural soils is a severe cause of concern globally. The heavy metals can enter crops through roots and can result in biomagnification in the different plant tissues such as roots, stems and leaves. From plants these metals are transferred into animal and human systems resulting in serious health problems. Various physical and chemical methods are available for heavy metal removal from soil but phytoremediation is considered as one of the most sustainable and cost-friendly method. Although many studies have been carried throughout the world to assess phytoremediation potential of plants in controlled conditions, few studies are available on the metal uptake capabilities of plants growing in natural conditions. Therefore, the present study was conducted to assess the phytoremediation potential of Trifolium alexandrinum (Berseem), an important forage crop growing in intensively cultivated agricultural soils of Punjab, India with main focus on the accumulation and mobility of metals (Cr, Cd, Cu, Co, Fe, Mn, Pb and Zn) in various plant tissues like roots, stems and leaves. The maximum contents of Cd, Co, Fe and Pb were observed in roots whereas for Cr, Cu, Mn and Zn maximum content was observed in leaves of Berseem. Overall among the metals studied Fe content was highest in all tissues of Berseem, which could be due to the higher content of Fe in soil. Metal Bioaccumulation Factor (BAF) and Translocation Factor (TF) calculated for assessing metal uptake and transport by plant tissues were found to be above 1 for the studied metals (except Co and Fe), which indicated Berseem to be a suitable accumulator of these metals in natural conditions.