Study of Lead Uptake and Translocation from Heavy Metals Contaminated Soils to the Aerial Parts of Different Winter Wheat Cultivars

The accumulation of heavy metals in agricultural soils, in addition to environmental pollution, increases the concentration and uptake of heavy metals in plants. In order to investigate theuptake and translocation of lead in four cultivars of winter wheat (Zare, Pishgam, Mihan and Orum), the effect of six levels of soil contamination by Pb (0, 25, 50, 100, 200 and 400 mg Pb/kg soil from lead nitrate [Pb(NO3)2] source) on the proposed cultivars were investigated as a factorial pot experiment with completely randomized design and three replications in the greenhouse conditions. The results showed that the levels of contaminated soil by Pb had a significant effect (P < 0.01) on Pb uptake of different cultivars of wheat. The highest amount of Pb uptake was measured in Mihan cultivar at level of 400 mg Pb/kg soil and was 2.67 mg in pot. The highest fresh weights of biomass, the highest accumulation of Pb in root and aerial parts, and the highest amount of Pb uptake by wheat were observed in Mihan and Pishgam cultivars at all levels of soil contamination, indicating that these cultivars have higher abilities to uptake and transfer Pb from the root to the aerial parts. The translocation factor of Pb was less than one for all four wheat cultivars at levels of 0 to 100 mg Pb/kg soil, while the bioaccumulation factor of Pb was more than one. As in the proposed wheat cultivars, the concentration of Pb in the root was higher than the one in aerial parts, they can be classified as excluder plants at these levels. Further studies are recommended in the field.