Purpose. To study the efficiency of consecutive selections when stabilizing ploidy, estimate tetraploid pollinators of Bila Tserkva origin for their combinational ability on yield and sugar content and determine their phenotypic manifestation in hybrids of sugar beet.Methods. Colchicination for transferring diploid lines to tetraploid. Cytological analysis of ploidy of tetraploid lines with negative plant selection of di- and triploid level. Top-crosses between tetraploid pollinators and pollen-sterile lines of different origin. Analysis of variance. Source material: tetraploid line-pollinators of C3–C5 generations from Bila Tserkva RBS’s collection originating from local populations of multigerm polyploid beet.Results. Resulted from colchicination tetraploid sugar beet pollinators were involved in the ploidy stabilization process. Cytological control of ploidy showed that individual selection is effective from generation to generation. In the generation C5, 98.8 to 100 % of plants obtained were with the double genome. The best numbers were included in top-crosses with pollen-sterile testers of different experimental germplasm to form triploid CMS hybrids and study the genetic control of yield and sugar content trait. The productivity of topcross hybrids was determined and combinational ability calculated. Line 1007 had significantly higher GCA in terms of yield, and line 1013 in terms of sugar content. The hybrids created with their participation, had the highest sugar recovery111.7 and 117.0 %, respectively, compared to the group standard. Tetraploid pollinators had the greater share of influence on the yield formation than sugar content.Conclusions. It was found that individual selection is effective for ploidy: the number of tetraploid forms grew on average by 66.3% in generation C3 to 98.8 % in the C5 generation. The number of triploid plants in populations of tetraploid forms of high generations depended on a genotype but did not exceed 3 %. A large role in the determination of the yield of top-cross CMS hybrids of Bila Tserkva RBS origin created from the best breeding tetraploid pollinators belongs to the effects of interaction between components (31 %) and sugar content (39 %). The contribution of the tetraploid component to yield formation was estimated at 35 %, while female component prevailed in the influence on sugar content (54 %). Selected were 10 promising hybrid combinations. Combinations CMS Ivan.27806 × Pollin.1007 and Ulad.28865 × Pollin.1013 had a high genetically based sugar recovery, 111.7 and 117.0 % higher than group standards, respectively. To obtain high-productive CMS triploid hybrids, complex breeding of tetraploid component in terms of CA, technological quality of roots and permanent control of ploidy is necessary.