Multigerm sterility maintainers of sugar beet: Evaluation and selection of promising breeding genotypes

Purpose. To study genetic characteristics of the sugar beet hybrid components for cytoplasmic male-sterile (CMS) hybrids − multi-germ pollinators (MSP) − and to select the best combination-capable pollinators with high adaptive potential and valuable agronomic traits. Methods. Breeding methods such as recombination, hybridization, and selection were applied, along with analytical, polycross, and topcross hybridization techniques. The parent forms were recombinant multigerm genotypes, the donors were aboriginal pollinators (AP), and the testers were monogerm CMS lines of the Verkhniachka Experimental Breeding Station. Results. It was established that yield and sugar content of MSPs depended on multiple factors, particularly the genetic potential of the breeding genotypes. To improve MSPs, polycross saturation hybridization was conducted, followed by an assessment of productivity parameters. The developed synthetic multi-germ hybrids were studied using the topcross method as parental components of CMS trial hybrids (TH). Conclusions. The study of the genetic nature of MSPs confirmed the possibility of developing parent components for THs. Thanks to high-sugar-content donor lines, new MSPs were developed. The best selected breeding genotypes contained a significant proportion of valuable genotypes, demonstrating high adaptive potential and a broad genetic base. By hybridizing these MSPs with CMS lines, even under stressful environmental conditions, it is possible to obtain hybrids with high productivity indicators.