The effect of heavy metals on spring barley (Hordeum vulgare L.).

Comparative toxicity of most heavy metals changes with the increase of impact (concentration) and only cadmium occurred to be most toxic in the entire range of investigated concentrations. In the case of relatively low concentrations, toxicity of investigated heavy metals decreased in the following order: Cd>Cr>Ni>Cu>Pb>Zn, and in the case of relatively high impact: Cd>Cu> Ni>Cr>Zn>Pb. More severe impact on the root growth at the comparatively low and medium concentrations, and more severe inhibition of shoot growth at higher concentrations of all investigated metals were detected. Stimulation of chlorophylls and carotenoids at lower concentrations is characteristic feature for the impact of metals. For most metals (Cu, Cr, Ni, Cd) maximal content of chlorophylls was registered in the range of concentrations between 1 and 3 μM.