FEATURES OF THE MANIFESTATION OF ELEMENTS OF PRODUCTIVITY OF SELF-POLLINATED MAIZE LINES OF BSSS GERM PLASMA UNDER THE INFLUENCE OF PLANT STANDING DENSITY AND CONDITIONS OF YEARS OF RESEARCH

Abstract

The relevance of the work consists in the selection of self-pollinated lines of corn (Zea mays) of the BSSS heterosis group, whose gene pool is still insignificant, adapted to the conditions of the Northern Steppe of Ukraine, resistant to adverse environmental factors. Introduction. Estimating the level of productivity elements of BSSS germplasm self-pollinated corn lines based on the main quantitative traits that determine their selection suitability greatly facilitates the selection of crossbreeding components for selection under certain conditions. According to some authors, the most effective selection for productivity can be directly based on the number of grains on the cob and the weight of 1000 grains (WTG) [2]. The number of rows of grains in a cob and their number in a row are determined by genetic systems and have clear quantitative limits. Also, under the condition of complete pollination of all flowers in the cob and the achievement of the maximum quantitative indicators for the plant (number of rows and grains in a row), the productivity potential of plants will be determined by the mass of grain from the cob [3]. Analysis of literary sources and formulation of research objectives. In Ukraine and the countries of Eastern Europe, the classification of the stages of development of grain crops, as well as growth phases, according to F.M. Kuperman [4]. The phase of the formation of the 7th leaf – 9th leaf is especially important, when the differentiation of panicle flowers occurs and pollen grains are formed in the anthers, and in the cob the beginnings of spikelets begin to form and the number of grains in a row is established. A feature of the 4th stage of organogenesis of the cob is a significant effect on the reduction of the overall productivity of plants in case of elevated temperatures and insufficient moisture supply. The phase of panicle appearance and panicle flowering and the beginning of the appearance of ovary columns (“silk”) are also critical. All subsequent stages of the organogenesis of the cob are related to fertilization and the formation of the grain, and their progress also depends entirely on climatic factors [5]. The main task of the research is the assessment and selection of self-pollinated lines of the BSSS heterosis group for drought and heat resistance, based on such economic and valuable characteristics as the number of grains on the cob and the weight of 1000 grains. The purpose and objectives of the research. The purpose of the work is to establish the selection and economic value of basic self-pollinated lines of corn in the creation of high-yielding corn hybrids adapted for cultivation in the conditions of the Northern Steppe of Ukraine, to identify the relationship between indicators of productivity elements and grain yield. Methods and materials. The research was carried out in 2021-2022, in the selective crop rotation of the SPF “COM PANY MAYS”, located in the Synelnykivskyi district of the Dnipropetrovsk region.. As an additional background for assessing drought resistance, two sowing densities were used: 50 and 70 thousand plants/ha. The given density was formed on the research plots manually in the phase of 4-5 leaves. The size of the plots is 7.00 square meters. The structure of the harvest was determined by counting the number of grains from the cobs selected from the plots during harvesting. In accordance with the “Methodology for conducting field experiments with corn” [7], the biological and economic characteristics of 25 self-pollinated lines of the germplasm group BSSS were studied. The results. The greatest value is represented by lines in which good grain size is combined with a high mass of a thousand grains. Self-pollinated lines of corn, which during two years of research under different agrotechnical conditions were characterized by more stable values of productivity elements (SDM15, SDM2A, SDM96, MC2439 and SDM84-35) and included in the program for creating drought-resistant hybrids.. Conclusions. It is recommended that lines SDM15, SDM2A, SDM96, MC2439 and SDM84-35 be used in breeding programs when creating hybrids with high productivity and drought resistance.