Induction of chlorophyll fluorescence use for assessment of functioning of Gentiana lutea L. plants photosynthetic apparatus in different conditions of culturing in vitro

Abstract

Aim. To study the peculiarities of functioning of photosynthetic apparatus of Gentiana lutea L. plants in vitro under different light qualities and source of carbon in the composition of nutrient medium by using the induction of chlorophyll fluorescence (ICF) method. Methods. Chlorophyll fluorescence was determined in light-adapted leaves of cultivated in vitro G. lutea plants by use of PAM fluorometry MultispeQ. The parameters change of photosynthetic apparatus functioning of cultivated in vitro plants was assessed with regard to light qualities (Variant 1: light intensity – 85 W/m2, when different spectra combinations of blue-wave band (Еb) and green-wave band (Еg) and red-wave band (Еr) was 33% : 42% : 25%; Variant 2: light intensity – 100 W/m2, with wave bands of spectra – Еb : Еg : Еr = 25% : 27% : 48%) and the source of carbon (10 g/l of sucrose or 3 g/l of mannite) in the composition of nutrient medium МS/2 (MS medium with half amount of macro- and microsalts), supplemented with 0.1mg/l of kinetin. Results. It was established that G. lutea plants cultivated in vitro for 90 days in light conditions of Variant 2 had a quantum yield photochemical of PS ІІ 8.3 % higher in comparison to G. lutea specimens cultured in light conditions of Variant 1. The vitality value of Variant 2 plants was 23 % higher. Change of carbon source in the composition of nutrient medium from sucrose (10 g/l) to mannite (3 g/l) was both increasing the efficiency of functioning of photosynthetic apparatus of Gentiana lutea L. plants in vitro and activating their resistance mechanisms to water deficit. Conclusions. The ICF method use shows that functioning of photosynthetic apparatus of G. lutea plants in vitro depends different qualities light and source of carbon in the composition of nutrient medium.
 Key words: induction of chlorophyll a fluorescence, plants in vitro, Gentiana lutea L.