STUDIES ON METAL UPTAKE BY PLANTS FROM SERPENTINE AND NON-SERPENTINE POPULATIONS OF THLASPI GOESINGENSE HÁLÁCSY (CRYCUFERAE).

Plants of a serpentine (S) and a calcareous (C) population-type of Thlaspi goesingense Hálácsy were raised from seed in various serpentine and artificial limestone soils with and without Zn amendment. S- and C-plants grown on metal-enriched substrates accumulated similar, extremely high concentrations of Ni, Zn, Co and Mn in the above-ground dry matter; they also showed a marked reduction of Ca uptake, which was combined with increased Mg uptake, in all the serpentine treatments. The fate of the Ni stored in seeds was followed when S-plants were grown in normal soil. Nickel was conserved and merely diluted within the plant dry matter as growth proceeded. Seedlings transplanted from serpentine soil to non-nickeliferous soil showed similar dilution effects, suggesting little or no overall Ni loss from the plant. The similar metal-uptake characteristics and performance of plants from the two populations studied suggests a constitutional metal tolerance within the species and the existence of a non-specific metal detoxification system.