Summary:
The scope of this doctorate study was to investigate the potential uptake of
chromium and nickel by carrots, onions and potatoes, as well as the potential
impact of these heavy metals on the activities of antioxidant enzymes catalase
and peroxidase in onions and potatoes.
The study included cultivation of tubers, in parallel irrigation lines, each
one supplied by an aqueous solution, containing different levels of Cr(VI) and
Ni(II) i.e. from 0 μg/L (control) to 1,000 μg/L. The soil used was obtained
from a certified organic greenhouse and was never, anthropogenically, polluted
in the past.
The results suggested that irrigation water containing Cr and Ni can
cross-contaminate onions and potatoes. No such evidence was found for carrots.
Also, Cr concentration in potatoes was found to be positively correlated with
Cr and Ni concentration in irrigation water.
The main findings of this study include, also, positive correlations between:
(i) Cr and Ni concentrations in carrots (ii) Cr and Ni concentrations in
potatoes (iii) Cr concentration and catalase activity in potatoes and (iv) Ni
concentration and peroxidase activity in onion leaves.
Finally, negative correlations have been observed between Cr and Ni
concentrations in onion shoots.
Keywords:
Chromium, Nickel, Enzymes, Uptake, Bulbs
