Toxicity of Cu, Pb, and Zn on Seed Germination and Young Seedlings of Wheat (Triticum aestivum L.)

Seeds and young seedlings of wheat (Triticum aestivum L.) under exposure to Copper (Cu), lead (Pb) and Zinc (Zn) were studied by employing a hydroponic experiment. Addition of Cu or Pb or Zn to the solution inhibited seed germination, plumule and radicle elongation. The toxic of metals to seed germination parameters can be arranged in the rank order of inhibition as follows: Cu > Pb >> Zn. This study showed the contents of chlorophyll and soluble protein in young seedlings of wheat were decreased after 4 d of all heavy metal treatments. Among the tested metals, the toxic of metal to young seedlings was found similar to seeds. All heavy metal concentrations in seedlings increase with their increase in the medium and the duration of treatments. On the other hand, the results demonstrated that the excess accumulation of Cu in leaf and roots could reduce accumulations of zinc (Zn); the excess accumulation of Pb decreased the levels of Cu or Zn in leaf and roots; the excess accumulation of Zn had no influence on Cu accumulations in leaf and roots.