The present invention relates to powdery mildew, and especially powdery mildew caused by the plant pathogen Erysiphe heraclei, resistant carrot plants or Daucus carota plants, wherein the powdery mildew resistance is provided by one or two dominant powdery mildew resistance genes. The present invention further relates to molecular markers genetically linked to the present powdery mildew, and especially powdery mildew caused by the plant pathogen Erysiphe heraclei, resistance providing genes and the use thereof for identifying carrots plants, or Daucus carota plants, being resistant to powdery mildew, and especially powdery mildew caused by the plant pathogen Erysiphe heraclei. The present invention also relates to seeds, plant parts, pollen, egg cells, callus, suspension culture, somatic embryos and edible plant parts of the present plants.