Research on the in vitro Bioaccumulation Capacity of Lead in Some Pteridophyte Species of the Romanian Flora

摘要

The aim of this article is to study the in vitro bioaccumulation capacity of lead in four autochthnous pteridophyte species: Asplenium scolopendrium (As), Asplenium trichomanes-ramosum (At), Cystopteris fragilis (CI), Polypodium vulgare (Pv), with a view to use them in phytoremediation processes. The polyphenol and flavonoid amounts determined in the material obtained after four months of in vitro culture, in a medium that contained 57.36 mg lead.kg(-1) Knop medium (V1), 286.82 lead.kg(-1) Knop medium (V2), 573.64 lead . kg 1 Knop medium (V3) were lower than the amounts determined in the control variants (C). The higher polyphenol concentrations of the V3 variants as compared with the V2 variants can be explained by the fact that phenolics provide protection against metal ions. In the V1 experimental variant, the highest lead concentration was determined for the species Polypodium vulgare, in the V2 variant the highest lead concentration was determined for the species Cystopteris fragilis and in the V3 variant the highest lead concentration was determined for the species Asplenium scolopendrium. The bioaccumulation coefficient varied from 0.78 in the Asplenium trichomanes-ramosum V2 variant to 1.97 in the Asplenium scolopendrium V3 variant. The results obtained in vitro, the amount of lead accumulated in the gametophyte and/or sporophyte tissues and the bioaccumulation coefficient obtained for the tested species, respectively should be completed by ex vitro tests performed on mature plants.