Scientific publications

A comparative analysis of changes in a number of indicators of growth, water exchange and cold tolerance in week-old seedlings of winter wheat cv. Moskovskaya 39 in the process of their adaptation to low-temperature hardening of different intensities (12, 8, and 4 °C) was carried out. The fresh and dry biomass of roots and shoots, the water content of tissues, the rate of stomatal conductance and transpiration, and the tolerance of leaf cells to freezing were studied. The greatest changes were noted under exposure to 4 °C temperature, which caused the maximum increase in cold tolerance. It was found that the accumulation of fresh biomass was almost completely inhibited at this temperature, but the accumulation of dry biomass of shoots continued, the water content, the rate of transpiration and stomatal conductance of leaves decreased. The temperature of 12 °С, causing a minimum increase in tolerance, led to the smallest changes in the studied parameters, and the treatment with 8 °С occupied an intermediate position. It is concluded that there is an obvious relationship between the level of tolerance achieved by hardening at low positive temperatures and the degree of manifestation of adaptive changes: the more significant and profound are the adaptive changes that occur in a plant organism under the influence of low-temperature exposure, the greater cold tolerance the plants are able to acquire under these conditions. Consequently, the program of adaptation of winter cereals to the cold will be realized the most fully precisely at the temperature that fosters the formation of a maximum level of tolerance.