Variability of yield components in winter wheat varieties and breeding lines under environment of Ukrainian Forest-Steppe

Abstract

Topicality. The main task of winter wheat breeding is to increase productivity, therefore, the development and introduction of new varieties of winter wheat with high productivity potential being well adapted to changing growing conditions into agricultural production is an urgent area of research. Breeders' efforts are aimed at developing varieties with a successful combination of high parameters of all the main productivity elements in one genotype, which will maximise grain yield. Breeding work is determined by many factors, among which the search and development of new genetic sources with high performance indicators. Therefore, the peculiarities of yield potential realization and the study of the mechanisms of productivity element formation under changing meteorological conditions are important for establishing the response rate and selecting the most stable productive genotypes and their further involvement in breeding programs. Purpose. To identify the best varieties and breeding lines of winter wheat in terms of productivity elements in the environment of the Forest-Steppe of Ukraine for their involvement in crossbreeding programmes. Methods. Visual – phenological observations; laboratory-field – determination of biometric indicators; mathematical and statistical – establishing the reliability of the obtained data. Results. It was found that the maximum realisation of the yield potential of winter wheat plants by structural elements occurred under optimal growing conditions such as in years with higher moisture availability and sowing on 5 October. Yield formation was significantly influenced by the weather conditions of the year, genotype and unaccounted factors. Sowing dates had a significant effect only on the manifestation of the plant height trait. There was a minor variation (3.8 %÷5.5 %) in plant height in all varieties and breeding lines. Different levels of variability were found for the following traits: number of productive stems varied from Cv=16.4 % (second sowing date in the dry 2019/20) to Cv=27.6 % (first sowing date in the favourable 2020/21); main head grain content and thousand grain weight – Cv=10.7÷17.6 % and Cv=8.8÷16.9 %, respectively. Regardless of varietal characteristics, the main spike length had insignificant (Сv=5.6÷8.8 %) phenotypic variability with a range of variation of 0.2–2.0 cm. There were determined the variability levels of traits by the spikelet number per spike (Сv=5.7 %÷8.6 %), by grain weight per spike (Сv=13.1÷20.5 %) and per plant (Сv=20.5÷36.3 %). Conclusions. The varieties MIP Assol, Hratsiia MYR, MIP Dniprianka, MIP Yuvileina and breeding lines LUT 55198, LUT 37519 consistently formed a high level of productivity elements regardless of sowing dates and conditions of the growing year, which indicates their high adaptive capacity. They are recommended for breeding programmes as valuable parental components. Key words: productivity parameters, trait, variation, sowing date, year conditions