Effect of copper on germination and seedling growth ofMinuartia, Silene, Alyssum andThlaspi

The influence of increasing copper concentrations on seed germination, seedling survival and radicle length ofMinuartia hirsuta, Silene compacta, Alyssum montanum andThlaspi ochroleucum was studied. Seed germination was highly affected by the higher Cu2+ concentrations (80 and 160 μM), while lower Cu2+ concentrations seemed to be necessary for seed germination, even for the plants originated from non-Cu2+-rich soils (i.e. A. montanum). Nevertheless, plants originated from Cu2+-rich soils (M. hirsuta, S. compacta) showed a higher demand of Cu2+ for rapid seed germination. Cu2+ at higher concentrations severely reduced growth rate of radicle, especially inA. montanum andT. ochroleucum. These data clearly indicate the reduced suitability of the above mentioned plant species for reclamation on Cu2+ soils. Lower Cu2+-concentrations had no influence on seedling survival inM. hirsuta andS. compacta, but a progressive reduction of a number of survived seedlings with increasing Cu2+ concentration was found, that was more pronounced inA. montanum andT. ochroleucum.