Effect of different concentrations of cadmium ions (0, 15, 60, 240 and 960 μmol dm-3 in full Hoagland solutions) on enzyme polymorphism of seven enzymes - acid phosphatase (ACP), alcohol dehydrogenase (ADH), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (PGD), phosphoglucoisomerase (PGI) and phosphoglucomutase (PGM) and their fifteen polymorphic loci - in coleoptiles, leaf blades and in the central parts of primary root systems of 14 days old seedlings in two self-pollinated maize lines and their single-cross was studied. Analyses of enzyme polymorphism showed that the biological material was homogeneous, self-pollinated lines had homozygous constitution in each analysed locus and hybrid had three loci (