Differential effect of metals/metalloids on the growth and element uptake of mesquite plants obtained from plants grown at a copper mine tailing and commercial seeds

The selection of appropriate seeds is essential for the success of phytoremediation/restoration projects. In this research, the growth and elements uptake by the offspring of mesquite plants (Prosopis sp.) grown in a copper mine tailing (site seeds, SS) and plants derived from vendor seeds (VS) was investigated. Plants were grown in a modified Hoagland solution containing a mixture of Cu, Mo, Zn, As(III) and Cr(VI) at 0, 1, 5 and 10 mg L−1 each. After one week, plants were harvested and the concentration of elements was determined by using ICP-OES. At 1 mg L−1, plants originated from SS grew faster and longer than control plants (0 mg L−1); whereas plants grown from VS had opposite response. At 5 mg L−1, 50% of the plants grown from VS did not survive, while plants grown from SS had no toxicity effects on growth. Finally, plants grown from VS did not survive at 10 mg L−1 treatment, whilst 50% of the plants grown from SS survived. The ICP-OES data demonstrated that at 1 mg L−1 the concentration of all elements in SS plants was significantly higher compared to control plants and VS plants. While at 5 mg L−1, the shoots of SS plants had significantly more Cu, Mo, As, and Cr. The results suggest that SS could be a better source of plants intended to be used for phytoremediation of soil impacted with Cu, Mo, Zn, As and Cr.