Aim. The goal of this study was to study the interaction of chronic ultraviolet (UV-B) radiation and cytokinin 6-benzylaminopurine (BAP) in the adaptation of pea plants (Pisum sativum L.) to the effect of chronic UV-B irradiation. Methods. Pea plants cultivar Aronis were sprayed by BAP solution in concentration 10-5 M before the effect of chronic UV-B radiation at doses of 6 kJ/m2 per day with a power of 1 W/m2 for 12 days. During this time, the growth of plants and their mass were measured, the content of photosynthetic pigments and endogenous hydrogen peroxide (HP) were determined in the leaves. Results. It was established that the effect of chronic UV-B radiation at a dose of 6 kJ/m2 per day on pea plants caused a delay in plant mass accumulation, synthesis of photosynthetic pigments and increasing HP content in leaves. Treatment plants by BAP increased mass, stimulated synthesis of photosynthetic pigments, reduced the content of HP in the leaves of pea plants during the UV-B radiation. Conclusions. It was shown that treatment of pea plants by BAP caused the adaptation of pea plants at the beginning of UV-B radiation. Cytokinins are capable to detoxify reactive oxygen spices, stimulate formation of photosynthetic complex that promotes growth of pea plants under chronic UV-B radiation.
Keywords: UV-B, BAP, Pisum sativum L., photosynthetic pigments, adaptation.