Indian Journal of Agricultural Research

A laboratory experiment was set up in order to quantify the impact of different concentrations of lead and cadmium (10, 30, 50, 70 and 90 μ mol L⁻¹) on germination physiology of Brassica napus L. The effects of lead (Pb) and cadmium (Cd) on seed germination, seedling growth, seedling dry weight and seedling vigor index were studied. Seed germination, seedling growth and seedling dry weights were significantly affected by different concentrations of Pb and Cd as compared to control. The increase in Pb and Cd concentrations caused progressive reduction in all the seedling growth parameters. Pb and Cd at concentrations of 90 μ mol L⁻¹ resulted in highest reduction in seed germination (14 and 21 per cent, respectively), seedling length (25 and 28 per cent, respectively) and dry weight (50 and 62 per cent, respectively) as compared to control. Seedling vigor index of B. napus gradually decreased with the increase in concentrations of Pb and Cd. The seedlings exhibited 77 and 72 percent of tolerance to Pb and Cd respectively at the concentration of 90 μ mol L⁻¹. This revealed that the inhibitory effects exhibited by Cd treatments were more prominent as compared to Pb at same concentration indicating higher phytotoxicity of Cd as compared to Pb.