Breeding of large-seeded lines of sunflower (He-lianthus annuus L.)

The aim of the study was to develop and evaluate selfpollinated largeseeded sunflower (Helianthus annuus L.) lines for subsequent use in breeding programs for confectionery hybrids. The work was carried out in 2023–2025 at the Armavir Experimental Station, a branch of V.S. Pustovoit AllRussian Research Institute of Oil Crops, using the pedigree method, laboratory and greenhouse tests. The thousandseed weight and resistance to the parasite Orobanche cumana Wallr. were evaluated. There was significant phenotypic variability in thousandseed weight, ranging from 38.1 to 247.4 g, which confirms the high potential of the parent material for directional selection. The most promising maternal lines were identified as In Kr11si2 and In Caliber, which are characterized by a stable manifestation of the trait and adaptability. Among the paternal forms, the most promising were the Chinese singlehead samples with distinct large size of seed and stability of the trait in different years of testing. Evaluation of the lines' resistance to broomrape revealed their high susceptibility to a virulent population; however, the line In (ImiJinn × Kalibr) showed partial tolerance. The results of the study indicate the high breeding value of the studied lines as parent material for developing new confectionery sunflower hybrids with a complex of economically important traits.