EN
Resistance to downy mildew was tested on resistant cultivars: Brasica oleracea PI246077 and PI231210, a broccoli-cauliflower line from Polish selection susceptible cauliflower lines and their F1 and F2 progenies.Infections degree of the inoculated plants was determined at the cotyledon and 4-5 leaf stages.To estimate score plant infection at the 4-5 leaf stage the Williams scale designed for plants inoculated at the cotyledon stage was modified.Resistance to the Polish fungus isolate proved to be dominant character.At the cotyledon stage depending on the source of resistance, it was determined by a four (in a broccoli-cauliflower line) or three (in PI USA) dominant complementary genes, while at the stage of 4-5 leaves - by a single dominant gene (in PI231210), two (in PI246077) or three (in the broccoli-cauliflower line) additive dominant genes.