The reaction of winter bread wheat cultivars to the stress effects of biotic and abiotic environmental factors

The purpose of the research is to study the degree of resistance of winter bread wheat cultivars to osmotic, salt and anaerobic stresses at the initial stages of plant growth for the selection of breeding valuable forms, to analyze the degree of resistance of cultivars to biotic stresses (development of diseases on seeds and vegetative plants) and to evaluate the relationship of growth parameters and adaptability with yield and productivity elements. The objects of the research were 11 cultivars and lines of winter soft wheat bred by the Federal Research Center “Nemchinovka”. The studies were carried out in laboratory conditions on the backgrounds of artificially simulated abiotic stresses on the 7-day-old seedlings using the roll culture method and in field experiments. The cultivars with the widest possible response rate to the toxic effects of the studied stressors, with the highest activation of growth processes and resistance to diseases were identified. The quantitative and qualitative composition of pathogens and patterns of changes in the phytosanitary status of seeds and germination depending on environmental conditions for the period of 1998–2023 have been determined. The level of correlation between the studied traits was investigated, the degree of influence of growth processes and adaptivity to stress on yield, weight of 1000 seeds and productivity elements was determined, and the important role of root system activation in the formation of these indicators was shown (r = 0.45–0.71). It was noted that in the initial period of plant growth, the relationship between stress resistance (drought and salt resistance index) and productivity elements (1000 seeds, grain weight per ear and the number of grains per ear) was negative (r = -0.41...-0.63). According to the totality of the studied characteristics there have been identified the culltivars ‘Moskovskaya 74’, ‘Moskovskaya 39’, ‘Moskovskaya 40’, ‘Moskovskaya 56’ and ‘Vasilyevna’ which occupy the 1st to 5th place in the rating of competitive advantage and are able to withstand stressful abiotic and biotic environmental factors both in laboratory simulated conditions and in the field.