Comparative Growth of Cereal Species Under Lead Stress

Some heavy metals in higher doses may cause metabolic disorders and growth inhibition. Lead (Pb) is the most common heavy metal contaminant in the environment. It is not an essential element for plants, but plants absorb it once it is in their environment, especially in rural areas when the soil is polluted by automotive exhaust and in fields contaminated with fertilizers containing heavy metal impurities. A study was conducted to determine the effect of different concentrations of lead on seed germination of four cereal species. Seeds were grown under laboratory conditions at 0, 0.15, 0.3, and 0.6 g/l of metal ions of lead. Lead treatment showed toxic effects on various germination indices of the cereals. Increasing the lead concentration to 0.6 g/l, the percentage of germination decreased significantly (p < 0.05) compared to the control in Triticum durum and Triticosecale Wittmack. Also, the dose of 0.6 g/l in Triticum aestivum causes undesirable effects on the germination coefficient of velocity. We can conclude that lead has a negative impact on the germination indices of cereal species. Among the genotypes evaluated, Hordeum vulgare is the most resistant against lead stress.