Reaction of simple sterile sugar beet hybrids to regulated environmental factors for sugar yield
Aims. According to the literature sources, the process of selection is marked with increase in breeding materials response to regulated factors and reduction to unregulated environmental factors. The objective of research was to investigate the combining ability expression in simple sterile hybrid components, as maternal components, under different combinations of strain test factors. Methods. Top-cross hybrids obtained by crossing five CMS lines and five sterility fixers were tested against the normal and enriched with mineral fertilizers backgrounds in variants with normal and extended growing space. Results. Established were the modifying factors influencing sugar yield; specific reaction of each genotype to regulated environmental factors for combining ability effects; shares of genotypic variation and change in value of its constituents in sugar yield trait. Conclusions. Genotype characteristics of breeding lines reveal themselves completely in extended growing space. The best hybrid combinations with high level of the trait manifestation at the phenotype level have been selected.
Key words: general combinational ability, specific combinational ability, environmental factors.