plant tolerance and metal uptake of some weed plants in a zinc contaminated soil

however some of heavy metals such as zn, are essential for plant growth, their elevated concentrations have toxic effects and may inhibit plant growth. in this study, plant tolerance and zn uptake and accumulation potential of some weed plant species from western azerbaijan region were studied in a soil spiked with 0, 1000, 3000 and 6000 mgzn kgsoil-1. seed of heliotrope (heliotropium europaeum), lambsquarter (chenopodium album), orach (atriplex sp.), amaranth (amaranthus retroflexus), millet (pennisetum glaucum), alfalfa (medicago sativa) and purslane (portulaca oleracea) were grown in pots containing the zn contaminated soil. at the end of growing season, plants relative yield (ry%), plants shoot metal concentration, metal bioconcentration factor (bcfzn) and plants metal extraction (mezn( from soil were measured. results showed that with an exception for lambsquarter and purslane, plants biomass decreased significantly (p≤ 0.05) with increasing zn concentration in soil, especially, in higher soil zn contaminations. compared with other plants studied, amaranth had the highest bcfzn and mezn in blank and 6000 mgzn kgsoil-1 treatments. amaranth, lambsquarter and orach with a relatively high biomass (750 to 960g dry matter bush-1 in native condithios) and middle rate of zn uptake might be effective in remediation of zn from contaminated soils