Aim. The goal of this work was to study the adaptive reaction of young corn plants (Zea mays L.) to the action of acute ultraviolet B (UV-B) radiation in the vegetative growth period. Methods. Corn plants hybrid Dostatok 300 MV in the phase of two leaves were irradiated by UV-B at doses of 1, 2, 4, 8, 16 kJ/m2 with a power of 6 W/m2 and were grown in a long day conditions. After irradiation, the growth of shoots in length, the growth of the mass of plants, the content of photosynthetic pigments and endogenous hydrogen peroxide (HP) in the leaves were determined. Results. It is shown that after irradiation of corn plants UV-B at doses of 4, 8, 16 kJ/m2 the growth of shoots in length decreased, after the irradiation of UV-B at doses of 1, 2 kJ/m2 mass of plants increased. UV-B irradiation in all doses, except for a dose of 16 kJ/m2, stimulated the accumulation of photosynthetic pigments in the leaves. Increasing HP content in the leaves was determined in corn leaves after irradiation of UV-B in all doses. Conclusions. It is shown that irradiation of young corn plants by acute UV-B at doses from 1 to 16 kJ/m2 induced adaptive reactions, that included inhibition of shoot growth with simultaneous stimulation of plants mass growth, accumulation of photosynthetic pigments, increased endogenous content of HP. The adaptive period lasted about 10 days, after that processes of growth, formation of a photosynthetic apparatus and content of HP were stabilized. UV-B belongs to the necessary components of sunlight components for corn growth.
Keywords: UV-B radiation, Zea mays L., photosynthetic pigments, adaptation.
PHOTOSYNTHETIC PIGMENTS AND PHYTOCHEMICAL ACTIVITY OF PHOTOSYNTHETIC APPARATUS OF MAIZE (Zea mays L.) LEAVES UNDER THE EFFECT OF THIAMETHOXAM