Sugar content variability in simple sterile hybrids as components of experimental hybrids as affected by genotype and environment

Purpose. To identify genetic determination and phenotypic expression of sugar content characteristic in simple sterile hybrids as parent components of experimental combinations as affected by nutrition background and growing space. To select the best ones in terms of their adaptive ability to abiotic environmental factors in multifactor experiment. Methods. Variety test of simple sterile hybrids, sterility maintainers and their simple sterile analogues in various environments as follows: normal fertilization background, normal growing space (NBNGS); normal background, extended growing space (NBEGS); enhanced fertilization background, normal growing space (EBNGS); enhanced background, extended growing space (EBEGS). Results. Differentiation capacity of NBEGS environment was higher than NBNGS (5 and 7 best hybrids were selected, respectively). Against the enhanced background, extended growing space also was the best for the selection of genetic lines for their sugar content characteristic. In EBEGS selected were 8 hybrids that greatly exceed average population value, whereas in EGNGS only 5. Proportion of non-additively genes action in EGS was also higher compared to NGS (50 vs. 40%). Conclusion. Established was variability of phenotypic manifestation of sugar content against the different fertilization backgrounds and growing space. The best hybrids featured stable effect on the sugar content against both backgrounds were CМS 1/Оt 2, CМS 2/Оt 1, CМS 5/Оt 1 and CMS 2/Ot 5, as evidenced by the cumulative effect of GCA and SCA. SCA was more variable in relation to the area of supply than GCA. CMC 1 and CMC 5 lines were distinguished as carriers of additive genes controlling sugar content and were characterized by stable phenotypic expression.