Physiological estimation of heat and drought resistance at the initial stages of winter barley ontogenesis

Drought and heat stress have significant effects on plant growth and productivity. In the natural environment, these abiotic stresses often occur simultaneously, which amplifies their negative effects. Therefore, understanding heat and drought influence on plant growth and productivity is particularly valuable. Winter barley, compared to other winter grain crops, is characterized by a relatively high resistance to moisture deficiency in soil and the effect of relatively high air temperatures. The current paper has highlighted the study of physiological indicators of winter barley resistance to moisture deficiency and high temperature effect. There have been presented the results of laboratory study for the period of 2022–2023. Identification of drought and heat resistance was carried out in the initial period of plant development on 100 winter barley samples of local selection and the VIR collection. The purpose of the study was to identify winter barley resistance to high temperatures and moisture deficiency using a set of laboratory methods. There has been studied the effect of sucrose solution of different concentrations (8, 12 and 14 atm.) and ambient temperature (52 and 54 °C) on the ability of seed germination under stress conditions. During the trials, there has been identified the best differentiation of resistance values under osmotic stress (8 atm.) and temperature (-54 °C). There have been identified the samples ‘Step’ (211.9 rel. units) and ‘HVW 36/72’ (157.9 rel. units) combining high resistance to osmotic and thermal stress, which reliably exceeded the values of the standard variety ‘Timofey’ by 25.3–79.3 rel. units.