Soraya Amir Ahmady; Tahmaseb Asemaneh; Athar Sadat Javanmard
Abstract
Although nickel is an essential element for plants, it has toxic effects at high concentrations. White clover (Trifolium repens) is a widely cultivated forage crop with high biomass. On the other hand, nickel pollution on farms has increased. Accordingly, in this study, the effects of nickel treatments ...
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Although nickel is an essential element for plants, it has toxic effects at high concentrations. White clover (Trifolium repens) is a widely cultivated forage crop with high biomass. On the other hand, nickel pollution on farms has increased. Accordingly, in this study, the effects of nickel treatments (at 0, 10, 50, 100, 200, 500, and 1000 μM levels) were investigated on seed germination characteristics of the plant in a growth chamber and then on biochemical and physiological parameters in hydroponic culture, in a completely randomized statistical design. The results showed that seed germination, percent and speed, seed vigor, and seedling length increased and decreased with low and high levels of nickel, respectively. Seedlings' death was observed at 100 μM and higher concentrations of nickel. Concentrations of 10 and 50 μM of nickel harmed biochemical parameters including chlorophyll, carbohydrate, protein, and peroxidase activity and raised the amounts of carotenoids. By increasing levels of nickel treatments, roots, and shoots nickel concentrations increased. In comparison to the control, treatments of 10 and 50 μM nickel concentrations led to an increase and decrease in stem dry weight, shoot length, leaf area, and leaf dry weight, respectively. It seems that 10 μM and 50 μM concentrations of nickel function as suitable and toxic levels for the growth of this plant, respectively. It also seems that white clover is a nickel-sensitive plant and not able to tolerate and accumulate nickel, and it is not a proper candidate for phytoremediation.
