Voronkova T.V., Kondratieva V.V., Olehnovich L.S., Ahmetova L.R., Molkanova O.I.

The effect of the spectral composition of light on some leaves biochemical and morphological parameters of Hydrangea macrophylla (Thunb.) Ser. regenerants under in vitro conditions

Hydrangea macrophylla (Thunb.) Ser. is one of the most popular ornamental crops used in landscaping. The growing area of H. macrophylla is expanding due to climate warming. Light plays an important role in plant ontogenesis, determining photosynthetic pigments and photomorphogenesis. n the photomorphogenesis of plants, an important role is assigned to the light of the red and blue bands of the spectrum. In the photomorphogenesis of plants, the light of the red and blue bands of the spectrum plays the greatest role. In our studies, a combination of red (70%) and blue (30%) spectra was used in the treatment of explants of the Bodensee H. macrophylla in vitro conditions. At the end of the illumination, the plants were subjected to low-temperature stress for 24 hours at t +2 ° C. The following physiological indicators were noted: the number of stomata, leaf thickness, epidermis thickness. Also we determined morphological parameters: the content of phenolic carboxylic acids: chlorogenic, caffeic, ferulic; abscisic acid and the amount of flavonoids. Morphological parameters were determined: the content of phenolic carboxylic acids: chlorogenic, caffeic, ferulic; abscisic acid and the amount of flavonoids. Additional illumination with red and blue light showed the best results in the process of plant development and adaptation to the effects of low positive temperatures.

Keywords: HYDRANGEA MACROPHYLLA, BLUE AND RED LIGHT SPECTRUM OF LIGHT, ADDITIONAL ILLUMINATION, PHYSIOLOGICAL INDICATORS, ADAPTIVE POTENTIAL