The results of using sunflower gene pool accessions (variety-population Kruiz, lines - sterility fixers Kh 1012 B, Mkh 215 B and Kh 52 B) in sunflower breeding for high content of oleic acid in oil are presented. During the period of 2007-2018, 52 self-pollinated lines were created, including 39 lines - sterility fixers and 13 lines - pollen fertility restorers, with high, medium and low content of oleic acid in oil. In 2019-2021, various expression levels of valuable economic and morphological features were determined in 15 lines - sterility fixers. The oleic acid content in oil from seeds of the lines was found to exceed 85%; the "seedlings-flowering" period lasted 53-59 days; the lines were highly resistant to rust, downy mildew and broomrape (parasitic plant). The lines are valuable sources for creating oleic sunflower hybrids.

Recently, the problem of phytosanitary condition of sunflower crops has been exacerbated, which is associated with violation of crop rotations and, as a consequence, spread of common diseases. Selection for resistance to biotic factors requires comprehensive research into the crop biology and pathogens. The use of starting material, which is resistant to major pathogens and environmental stressors, in selection is a prerequisite for the breeding of highly productive hybrids. Significant progress in the breeding of heterosis sunflower hybrids has been achieved primarily due to stable inbred lines. However, their creation is time-consuming, taking 8-12 years. Selection of desirable genotypes and initial forms for crossing is complicated by the fact that it is driven by a set of polygenic traits that are prone to significant modification variability. The use of molecular genetic markers is a way to accelerate breeding. Marker-assisted selection breeding (MAS) has been theoretically justified in numerous publications and implemented in most breeding institutions around the world. However, in domestic breeding programs, MAS has not become widespread compared to traditional methods. Nevertheless, this breeding trend opens new opportunities for studying genetic diversity and determining kinship at the intraspecies and genus levels. The review provides information on the status and prospects of implementation of MAS in traditional plant breeding and highlights the achievements of modern biotechnology in sunflower breeding for resistance to biotic factors owing to molecular genetic markers. The MAS principles are outlined and the advantages of this method are described. Specific examples of application of the molecular approach during the development of starting material of sunflower for breeding for resistance to common diseases and parasites are given. The main stages and components of PCR analysis are also described. Inbred sunflower lines – carriers of the gene for resistance to the downy mildew pathogen are characterized and genetic passports using STS markers to the Pl6 locus have been formalized for 13 sunflower lines.