Dynamics of growth parameters of Gentiana lutea L. in vitro plants under different lighting conditions

Aim. Study of the dynamics Gentiana lutea L. plant growth processes in vitro depending on the light regime changes of their cultivation in order to develop a scheme to increase their adaptive potential. Methods. Methods of plant cultivation in vitro, biometric method, as well as ANOVA variance analysis and middle group analysis in pairs using the Tukey test (Tukey test) were used. Results. It is shown that the cultivation of G. lutea plants in vitro using 25 W/m2 light flux intensity in the region of photosynthetically active radiation and the ratio of blue (Eb): green (Eg): red (Er) ranges = 41.8%: 42.7 %: 15.5% triggers non-specific photomorphogenesis reactions for intact plants, which lead to poor root system development, stem elongation, formation of small leaves with a thin leaf blade, overall low productivity and low adaptation potential of G. lutea plants to ex vitro and in situ conditions. Increasing the light flux intensity to 44 W/m2 and increasing the red wave proportion up to 20.3% allows not only to improve the bioproductivity of G. lutea plants which are cultivated in vitro, but also to increase the coefficient of microclonal reproduction without the additional use of exogenous growth regulators. The greatest growth of the aboveground and underground parts, increase in effective leaf surface are observed in vitro plants during cultivation at 135 W/m2 light flux intensity and spectral composition Eb: Eg: Er = 29.5%: 32.5%: 38.0%. Conclusions. It is possible to improve plant bioproductivity by changing the light conditions of plant cultivation in vitro, and, accordingly, to increase the adaptive potential to ex vitro and in situ conditions. Keywords: Gentiana lutea L., in vitro plants, light flux intensity, spectral composition, growth parameters.