M. Drumeva, N. Nenova, E. Penchev

Abstract. Sunflower, being one of the main oil seed crops in the world, is of special economic importance in East Europe. In sunflower breeding the heterosis effect is primarily used. The high yield and the quality properties of seeds depend on the indices of the lines in their pedigree and require the developing of lines with good bio-chemical and technological indices. This investigation involved 5 fertility restorer lines produced by using pollination technique with high gammairradiation doses and subsequent embryo cultivation, 4 cm lines obtained through selfing, and their hybrid combinations. Applying various mathematical models, the correlation between the individual indices (1000 seed weight, percent of kernel, percent of husk, oil content in kernel, oil content in seed and protein content) was demonstrated. The performed analysis revealed negative correlation between the two main quality traits: oil content and protein content. Oil content in kernel correlated insignificantly negatively with the trait 1000 seed weight, while protein content in kernel was in a significant positive correlation with the 1000 seed weight. The established correlations can be directly used at the initial stages of investigation on the breeding materials.