EN
The effects of stress conditions in a polluted environment on the reproductive processes of plants were studied for two successive years. Vicia cracca is a component of the spontaneous green belt at the base of a copper processing post-flotation waste reservoir (Żelazny Most, Legnica-Głogów Copper Basin, Silesia, Poland). Plants from the site were compared with plants derived from seeds harvested from the contaminated site which grew in non-polluted soil on an experimental plot near Cracow. Almost all of the studied flowers showed degenerative tapetal processes in ~50% of the anthers, starting simultaneously in various stages of meiotic divisions in the pollen mother cells. At the tetrad stage nearly 50% of the anthers contained wholly degenerated tetrads. Disturbances in meiosis increased the amount of degenerated pollen grains. The proportion of potentially functional pollen grains was 47% in 1997 and 56% in 1998; in the control material the corresponding proportions were 87% and 84% (1998 and 1999). Various kinds of developmental disturbances and degenerative processes eliminated some of the ovules from the seed production. The percentages of ovules forming seeds was 56% and 59% in successive years (85% and 87% in the control). Most of the disturbances and degeneration can be attributed to the combined negative impacts of specific environmental factors.