EN
Determination of ploidy level is a comon practice in sugar-beet breeding and seed production.Lately many laboratories have replaced microscopic chromosome counting by flow cytometric estimation of the nuclear DNA content. The possibility of direct estimation of cytological composition in anisoploid populations instead of individual plants analyses was investigated.Diploid, triploid and tetraploid sugar-beet lines as well as their mixtures were tested.The results obtained show that the suggested method is fast, simple and, after a proper transformation of the computer values, could be applied in breeding and seed production of polyploid crops.Precise estimation of contamination by small admixture of seeds or plants of undesirable ploidy, however, requires individual plant rather than population analyses.