Abstract
The main diseases of sunflower which can be controlled by major genes are downy mildew, broomrape, rust and Verticillium wilt, whereas the crop shows quantitative resistance to Sclerotinia rots and wilt, phomopsis stem canker, Phoma premature ripening and black stem and Alternaria. Over the past 40 years, knowledge of the genetics of resistance to all these diseases has increased, but it is only for major gene resistance that marker-assisted selection is used routinely in breeding. Improvement of quantitative resistances still depends largely on field observations, markers are not yet used to select favourable alleles at quantitative trait loci. Genomic selection could be a means to improve quantitative resistances at a low cost, if RIL populations or core collections phenotyped in the past have been maintained.