Abstract:

Heavy metals are hazardous pollutants for humans, animals and plants, when their threshold concentration exceeds. Tobacco can accumulate higher concentrations of heavy metals, and the genotypic differences of tobacco in heavy metal uptake and their growth responses have not been clearly examined. In this study, the effects of nickel (Ni) and lead (Pb) on phytoremediation capabilities were tested in four local Oriental tobacco cultivars (Basma, Akhisar, Sarıbağlar and Dibek). In two pot experiments, nitrogen (N), phosphorus (P) and potassium (P) were applied in fıxed doses, while Pb and Ni were applied at 4 different doses (10, 50, 100 and 150 mg kg-1). Plants were harvested after 50 days of growing period, and separated into roots, stems, leaves. The biomass values were measured, and Pb and Ni concentrations were quantified in plant organs. Results revealed that Basma cultivar had the highest total biomass value with 16.63 and 15.92 g pot-1 for Ni and Pb contents, respectively. While, the lowest total biomass was recorded in Dibek cultivar with 7.09 and 5.71 g pot-1 for Ni and Pb, respectively. The biomass, Ni and Pb uptake and accumulation capabilities remained in the following order of cultivars Basma > Akhisar > Sarıbağlar > Dibek. Depending on the application doses, Ni and Pb concentrations of different plant parts (roots, stems and leaves) of all varieties showed significant (p < 0.01) increases compared to the control treatments. All of the plant parts of Basma variety had higher Ni and Pb concentrations than the Akhisar, Sarıbağlar and Dibek variety. Nickel concentrations in the roots, stems and leaves of different cultivars were determined to be the least in the control application and the highest in the NPK+150 mg kg-1 Ni (Ni4) application. Lead concentrations in the roots, stems and leaves of different cultivars were determined to be the least in the control application and the highest in the NPK+150 mgkg-1 Pb (Pb4) application. Basma variety with higher enrichment factor (EF) and bioaccumulation factor (BAF) values were also found to be more effective than the other varieties for phytoremediation of Ni and Pb. The objective of this study was to examine the Ni and Pb uptake, transport and accumulation properties of oriental tobacco with special emphasis on its different varieties.

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