Mixture toxicity of different metal ions in cytogenetic biotests

The separate and combined impacts of aluminium and selenium ions on different barley cultivars and onion (Allium cepa L.) seedling as well as ions copper, zinc and nickel on onion have been studied. The experiments have been performed in several series with different solutions of ions: aluminium have been used in concentration of 0.5 mg/l (Russian MPC for cultural-domestic water), ions of Fe, Mn, Se, Ag and their combinations with ions of Al have been used in concentrations corresponding to the values of Rus MPC for cultural-domestic water. At the same condition were chosen the concentrations of copper, zinc and nickel. The phytotoxic and genotoxic effects (as mitotic index – MI and aberrant cell frequency – ACF) were estimated. It was showed that aluminium ions promote higher phytotoxic and genotoxic effects, but in combined with another ions the negative effects on barley and Allium cepa reduced. This confirms that the universal mechanism the interaction between two metals (aluminium and other) and their detoxification effect in plant. The essential metals Cu and Zn and the toxic metal nickel provide a strong cytogenetic effect which results to ACF increasing and MI suppression. We assume that the mechanisms of detoxication should be initiated by metals themselves. (paper)