Chromosome numbers in somatic cells of Setaria pumila and S. italica were investigated. Setaria seeds, brought to Lithuania as imported grain contaminants, were taken for investigation. Seeds of Setaria plants were found in 18 samples from five European countries. Diploid individuals of S. italica (2n=18) from Italy and tetraploid individuals of Setaria pumila (2n=4x=36) from Byelorussia, Moldova, Russia, and Ukraine were determined. Chromosome numbers of four local populations of S. pumila ir S. viridis were also investigated. In two Lithuanian populations tetraploid (2n=36) individuals of S. pumila and in two populations of S. viridis diploid (2n=18) were recorded.
Keywords: Setaria, chromosome number, polyploidy level, weeds, alien species.