Ts. MARTIROSYAN1, 3, T.A. DILOVAROVA1, V.V. MARTIROSYAN1, V.D. KRESLAVSKII2, A.A. KOSOBRYUKHOV1, 2 1All-Russian Research Institute of Agricultural Biotechnology, Federal Agency of Scientific Organizations, 42, ul. <...> Timiryazevskaya, Moscow, 127550 Russia, e-mail yumart@yandex.ru; 2Institute of Basic Biological Problems, Federal Agency of Scientific Organizations, 2, ul. <...> Emanuel Institute of Biochemical Physics of RAS, Federal Agency of Scientific Organizations, 4, ul. <...> Kosygina, Moscow, 119991 Russia Acknowledgements: Supported in part by the grant from Russian Foundation for Basic Research 15-04-01199а Received April 6, 2016 A b s t r a c t In vitro reproduction is an important stage in seed potato propagation. <...> Various radiation spectra can be used to regulate in vitro the growth and morphogenesis of potato seedlings (Solanum tuberosum L.). <...> We studied the effect of light emitting diodes (LEDs) light sources, which differ in the spectral composition of the radiation, on the growth processes and functional parameters of the photosynthetic apparatus in potato plants (variety Agria) grown in vitro. <...> The red LEDs with λm = 635 nm and the half-width of the emission band (HW) of 45 nm, blue LEDs with λm = 463 nm (HW = 23 nm), green LEDs with λm = 521 nm (HW = 38 nm), and white LEDs (400-730 nm) with an intensity of light equal to 60-65 micromol photons∕m-2∕s-1 at plant level, and white fluorescent lamps (OSRAM AG, Germany) of the same light intensity were used. <...> On day 28 the growth parameters, CO2 gas exchange rate and parameters of variable chlorophyll fluorescence were measured. <...> A smaller plant biomass accumulation was observed when plants were irradiated with white LEDs. <...> The observed changes in the accumulation of dry plant biomass for different spectral ranges are associated with a higher activity of the photosynthetic apparatus of the plants grown under irradiation with blue and white LEDs. <...> The rate of photosynthesis (per unit of the leaf surface) in these plants was higher than in those grown under green or red LEDs. <...> The effective quantum yield of PS 2 in all studied plants had small changes in the range of 0.47 to 0.53, but higher values were observed <...>