Fluorescent indices of ornamental plants treated with growth regulators
Luminescent indices of photosynthesizing species depend on various biotic and abiotic factors and seem to be very attractive for monitoring the state of the photosynthetic apparatus and for assessment of their functional activity. The use of plant growth and development regulators, as well as of multicomponent organo-mineral fertilizers, is a promising trend in the technology of growing crops and obtaining high yields. The positive effect of these preparations is to increase the resistance of plants to stressful influences – high and low temperatures, moisture deficit, soil salinity, etc. In this work, we have studied the fluorescent indices of several ornamental plants sprayed with the preparations “Epin-Extra”, “Zircon”, and “Siliplant” possessing an immunomodulating effect. The fluorescence kinetics of Chl a in the leaves was measured using a PAM-2500 pulse fluorometer (Walz, Germany). The PAM-fluorescence technique provides a number of parameters characterizing the efficiency of various processes taking place in the photosynthetic apparatus. One of these parameters is ФPSII = (Fm' - F)/Fm' characterizing the effective photochemical quantum yield of PSII. The coefficient of the nonphotochemical quenching NPQ was calculated as NPQ = Fm/Fm' - 1. Some differences were found in the values of these parameters for control and experimental plants. These differences indicate an increase in the efficiency of the photosynthetic apparatus of the studied plants under the influence of immunomodulators.
Lomonosov Moscow State University, Faculty of Physics
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