Purpose. Reveal the features of the formation of a quali­ty indicator complex in winter bread wheat depending on the growing seasons, preceding crops and sowing dates, as well as differentiate and identify genotypes with high and stable levels of manifestation. Methods. Field, laboratory, statistical. Results. A different share of the influence of the year conditions, the preceding crop, the sowing date and their interactions on the quality indicators of some varie­ties was determined. A different reaction of varieties in terms of quality indicators, depending on the investigated factors was revealed. The variation was very low for test weight, water absorption ability of flour, crumb porosity. Strong variation was observed for flour strength after sunflower and soybean as preceding crops, alveograph configuration ratio after sunflower and soybean, index of elasticity dough after corn, valorimetric value after mustard, dough dilution degree after green manure, sunflower, corn and especially after mustard and soybeans. The varieties, which on average for 2016/17–2018/19 reliably exceeded the standard both in individual indicators and in general in terms of physical indicators of grain and flour quality and dough rheological properties. GYT biplot analysis identified the genotypes ‘MIP Vidznaka’ and ‘MIP Assol’ with a more optimal combination of increased yield and a complex of quality indicators in terms of different years, preceding crops and sowing dates. Some varieties, namely, ‘Estafeta myronivs’ka’, ‘Trudiv­nytsia myronivs’ka’, ‘MIP Valensiia’, ‘MIP Yuvileina’, ‘Balada myronivs’ka’, ‘Vezha myronivs’ka’ were inferior to them, but were significantly superior the others. Conclusions. The selected by quality indicators varieties as genetic sources can be used in breeding process. A more stable level of yield and quality indicators at different sowing dates after different preceding crops should be expected for growing varieties ‘MIP Vidznaka’, ‘MIP Assol’, as well as ‘Estafeta myronivs’ka’, ‘Trudivnytsia myronivs’ka’, ‘MIP Valensiia’, ‘MIP Yuvileina’, ‘Balada myronivs’ka’, ‘Vezha myronivs’ka’. The peculiarities obtained in the research should be taken into account when evaluating and differentiating genotypes in breeding process, as well as developing basic elements of technology for growing the varieties of winter bread wheat.

Purpose. To study the effect of weather conditions on grain quality in soft spring wheat lines that are undergoing competitive variety trial. To identify indices to be least affected by weather conditions. To investigate the correlation dependence between grain quality indices in the years with contrasting weather conditions and conduct the analysis of variance. Methods. Parameters of grain and flour quality of bread spring wheat lines were determined using conventional methods at the laboratory of grain quality of V. M. Remeslo Myronivka Institute of Wheat, NAAS of Ukraine, protein content in flour was measured with the use of the SPECTRAN 119M device. Results. Contrasting weather conditions were considered including arid ones (2013) – that had negative effect on 1000 kernel weight, but at the same time positively influenced the averaged grain quality indices; with excess humidity (2014) – they resulted in decreasing of all technological indices; optimal ones (2015) – allowed to obtain maximum indices of grain and flour quality. Paired coefficients of correlation between different para­meters of grain and flour quality were calculated. The most number of strong and medium correlations was found in a dry year (33.3%), the smallest one – in a wet year (13.0%). Such indices as flour strength, dough dilution and protein content depended on the conditions of the growing year least of all. Grain-unit response was the most considerable to the humid conditions of the year. The analysis of variance showed that climatic conditions had significant effect on the quality indices of grain and flour. At the same time, an important genotypic component was revealed in indices of dough resilience (63%), bread volume and rating (61 and 53% respectively), the flour strength (42%), crude gluten quality (33%), bread porosity (30%). With climate variations, the genotypic conditionality of the content of protein and especially crude gluten was expressed insignificantly. Conclusions. When creating high quality cultivars, plant breeders should be guided by such indices as flour strength, dough resilience, gluten quality, bread volume and rating as only they are more genetically determined