growth and accumulation responses of populus nigra l. exposed to hexavalent chromium excess

phytoremediation of heavy metals is employed as a technological approach for a non-destructive remediation of contaminated soils. one of the most recently studied tree species used in phytoremediation applications are poplars. in this study, the one-year old rooted seedlings of populus nigra l. used to decontaminate hexavalent chromium-contaminated soils. five treatments of cr (vi) supply (were spiked as potassium dichromate) including 0 (control, no external cr = t0), 50 (t50), 100 (t100), 125 (t125) and 150 mg.kg-1 (t150) were employed. it was found that this species not only can reduce large amounts of cr (vi) in the soil, but also can uptake and accumulate this element in its organs. both mentioned mechanisms were found to be dose-dependent. a significant linear regression was observed between the all biomass parameters except root diameter (p ≤ 0.05) as well as cr accumulation in plant tissues (p ≤ 0.01) and chromium concentration in the soil. these findings suggest that this species is suitable for cr (vi) biomonitoring programs of cr environmental contamination.