Effect of Cd in combination with Cu, Zn, Pb and Fe on root prolongationand metal accumulation in the roots and cotyledones of mustard (Sinapisalba) seedlings

摘要

Mustard (Sinapis alba) seedlings were used to evaluate the combined effect of Cd with Cu, Zn, Pb and Fe on root prolongation and metal accumulation in the roots and cotyledones. All metal-metal combinations significantly inhibited root growth compared to the control as well as both metals alone. The exception was determined only for combination Cd + Zn when in comparison with both metals alone no significant difference in root prolongation was confirmed. Therefore the reciprocal synergistic effect was confirmed between Cd and Cu, Pb and Fe but not between Cd and Zn when additive effect was observed. The accumulation of metals independently whether they were applied individually or in metal pairs was higher in the roots than in the cotyledones. In the highest amount were accumulated as individual metal in both plant parts Cd and Cu. When metals were in solution in pairs, they mainly affected each other in their accumulation in the roots. Metals applied in combinations were accumulated in roots in lower amounts than metals applied individually. Only Cd in combination with Zn and Fe was accumulated in amount not significantly lower than in presence of Cd alone. That indicates that Zn as well as Fe did not influence Cd accumulation and their effect to Cd was additive. When the accumulation of metals in combinations was determined in cotyledones. no significant differences in comparison with both metals alone were confirmed. Only accumulation of Fr and Pb was in combination with Cd rapidly decreased to 2.5% and 15.1%. respectively. It can be concluded that Zn, Cu and Fe had an additive effect on Cd accumulation in cotyledones. Cd had an additive effect to Zn and Cu but very strong antagonistic effect to Fe and Pb accumulation in cotyledones.