Abstract:
The potential of the model crop Brassica napus L. (rapeseed) for the phytoremediation of soils
polluted with metals was investigated at laboratory scale. The first step consists in the evaluation
of the seed germination and growth of the Brassica napus L. plant in a controlled environment,
followed by the determination of the photosynthetic pigments content represented by chlorophyll
a and b and carotenoids. The degree of metal accumulation in rapeseed has been evaluated by
the bioaccumulation factor (BAC), the bioconcentration factor (BCF) and the translocation factor
(TF). Phytotoxicity tests were performed in Petri dishes with filter papers moistened with metal
solutions in the range of 0 to 300 mg/L Pb(II) or Cd(II). At the highest concentration of the lead and
cadmium treatments (300 mg/L), B. napus L. showed the lowest germination degree (56.67% and
43.33%, respectively). According to Tukey test results, Pb(II) concentrations of up to 300 mg/L do not
significantly affect the length of the hypocotyls, whereas, in the case of Cd(II), the mean of the radicle
and hypocotyl lengths of the seedlings are significantly affected compared to the mean of the control.
In soil pot experiments, important changes have been obtained in the pigment content, especially
in the case of cadmium. For both metals and for each treatment (100 to 1500 mg/kg Pb(II) and 1 to
30 mg/kg Cd(II)), a TF < 1 indicates an ineffective metal transfer from root to shoot. Finally, rapeseed
can be considered a tolerant plant and a suitable candidate for Pb(II) and Cd(II) accumulation and
for the phytostabilization of contaminated soil under the experimental conditions adopted in the
present study.
