Justification and improvement of methods for determination of sunflower resistance to major pathogens by its variability patterns

Success of creation of competitive hybrids depends, on the one hand, on availability of valuable breeding material, and on the other hand, on development of a system of immunological assessments and criteria for selecting initial material that is resistant to major diseases. The problem of sunflower resistance to diseases in Ukraine has grown due increasing incidence of downy mildew ( Plasmopara helianthi Novot. f. helianthi ), Phomopsis blight ( Phomopsis / Diaporthe helianthi Munt.-Cvet. et al.), and gray rot ( Botrytis cinerea Pers.) associated both with changes in crop rotation patterns and with cyclical changes in weather conditions. This problem impelled evaluating levels of resistance of modern sunflower hybrids to these pathogens and selecting resistant ones to stabilize the phytosanitary condition and to increase in the crop yield in production. The scientific novelty of the research consists in the improvement of methodological fundamentals of the crop breeding and differs from previous studies by the development of a system of immunological assessments of parental germplasm for resistance to downy mildew, Phomopsis blight and gray rot pathogens using statistical analysis for practical use of it in the crop breeding programs...