Effect of enhanced lead in soil on growth and develoment of Vigna radiata (Linn.) wilczek

Lead nitrate (2.5 to 7.5 g/kg soil) treatment resulted in a decrease in plant height, root-shoot ratio, dry weight and nodule number per plant. Stomatal index of leaves increased with higher concentration of lead. A loss in chlorophyll content was noticed, chlorophyll a was more affected than chlorophyll b, while carotenoids were least affected. Protein content of leaves, stem and roots decreased under the influence Pb in soil, with most pronounced reduction in roots. A gradual decline in the nitrate reductase activity was observed in treated plants. Seed germination remained unaffected at low concentrations, but was completely inhibited at higher concentrations of lead.