Influence of abiotic factors on the variability of the seedling – flowering period in the parental components of maize hybrids

Topicality. Maize is a monoecious cross-pollinated plant with a well-defined proterandry, however, some maize samples show persistent proterogyny. A significant manifestation of proterandry and proterogyny tends to negatively affect the pollination quality of ears and the yield of lines during reproduction. Synchronisation of flowering the ear in the female component and the tassel in the male component is essential for the reproduction of sterile analogues of self-pollinated lines and for production of F1 hybrid seeds. Since the lack of coincidence in flowering dates can cause poor pollination and the formation of ears with incomplete kernel set and further loss of seed yield. Purpose. To determine the variability of the seedling – flowering period of female and male inflorescences of parental components in maize hybrids under the influence of abiotic factors. Materials and Methods. The research was conducted at the Institute of Grain Crops of NAAS of Ukraine during 2018–2021. In the experiment, 15 parental components of maize hybrids were used: DK216M sterile, DK216SVZM, DK273MV, DK777M, DK777ZMSV, DK680MVZS, DK315M sterile, DK315SVZM, DK239MV, NT 004 sterile, NT 004 fastener, TT005, DK2064M, DK2064SVZM, DK633/325 MV. The flowering date for inflorescences of parental components was recorded at flowering of 50% of plants on the plot. Results. The agrometeorological conditions were quite contrasting over the years of research, which allowed us to comprehensively assess the variability of the seedling-flowering period of female and male inflorescences in the parental components of maize hybrids. We found that the parental components were differently sensitive to environmental changes; the dichogamy of flowering of male and female inflorescences in most maize genotypes has traits of proterandry. Proterogyny was observed in some samples under cool weather conditions with high precipitation. Conclusions. We found that abiotic factors affect the variability of the seedling-flowering period for female and male inflorescences in the parental components of maize hybrids, however, in our experiments, the variability of the seedling-flowering period in maize was very low. The obtained results indicate the possibility for reliable seed production of maize hybrids DN Synevyr, DN Svitiaz, DN Halateia, Monika 350 MV, DN Vesta in the Steppe of Ukraine. Key words: maize, parental components, seedling-flowering period, proterandry, proterogyny, range of variation, coefficient of variation