Variation of spring barley’s quantitative traits of samples in the conditions of the central Forest-Steppe of Ukraine

The aim of the research was to determine the level of quantitative traits (number of spikelet and grains per ear, weight of 1000 grains) of spring barley breeding material, to determine genotypic and environmental variance as components of the overall phenotypic and degree of genetic and environmental variation. Methods. During six years (2018-2023) we observed four varieties and 12 breeding numbers of spring barley. Based on the results obtained, the coefficient of variation was determined separately for each genotype and each year using the Excel program. The seeding rate of spring barley seeds in the experiment was 4 million per ha. The registered area of the plot was 4.00 m2. Results. The average number of spikelet in an ear in the analyzed material was 19.8-23.0 pcs. This indicator varied by genotype on average in 2018 and 2023, in 2019, 2020, 2021 and 2022 - slightly. Depending of the year, the indicators varied significantly for all biotypes. The average environmental variance was 32.7%, which was eight times higher than the average genotypic variance (4.4%). The total phenotypic variance was 37.1%. The average number of grains per ear ranged from 13.0 to 17.0. The coefficient of variation due to differences in the years of research was medium and significant. At the same time, the average environmental variance was 11.2%, varying in different biotypes from 3.9% in variety 7/23 to 24.7% in selection number 15/23. The genotypic variance averaged 8.7%, and the total phenotypic variance was 19.9%. The number of grains per ear by genotype varied significantly in 2018, 2020 and 2021, and was average in 2019, 2022 and 2023. The weight of 1000 grains was on average 40.2-52.6 g. It varied moderately depending on the genotype in 2018, 2019, and 2023, and slightly in 2020, 2021, and 2022. Depending on the year`s conditions, the weight of 1000 grains varied slightly and moderately. Conclusions. The number of spikelet per ear is determined by growing conditions rather than genotype. The variation of the number of grains per ear depending on environmental conditions and genotype was medium to significant. The weight of 1000 grains varied moderately and slightly depending on the genotype and the year’s conditions.