A simple method of a bicolor (multicolor), fast-Fourier, PAM chlorophyll fluorometry has been developed to obtain fluorescence induction curves. Quantum yields of PSII photochemistry were determined with blue and red simultaneously applied pulsed measuring lights for three subsequent 20-min periods of dark-, light-adaptation under actinic light and dark recovery. Measuring lights were cross-combined with blue and red actinic lights and saturation pulses. Coefficients of chromatic divergence were calculated as a ratio of the quantum yields obtained by red measuring light to that obtained by blue measuring light. Adaptation of Ficus benjamina and Hordeum vulgare leaves under blue (but not red) actinic light resulted in the sufficient increase of chromatic divergence. In addition, fraction of active, non(photo)inhibited, PSII centers was shown to be dependent on the color of measuring light. Thus, color of the light sources should be considered when reporting results of parameters evaluated from fluorescence induction curves., V. Lysenko, D. Lazár, T. Varduny., and Obsahuje bibliografii
Two differently coloured strains of the genus Chroococcus were isolated from a cyanobacterial assemblage collected from the stony littoral of a backwater of the Danube River in southern Slovakia. When grown after isolation, both subcultures were similar morphologically and their growth parameters did not differ substantially, but their pigment content (PC: PE and carotenoid ratios), details in their morphology during their life cycles and slime production were different. Identical and different characters of both morphotypes remained stable during cultivation on both agarized and liquid media, even when the cultivation parameters were changed. Both of the subcultures were studied using electron microscopy and almost their complete 16S rRNA genes were sequenced, which showed that in terms of their genetic relationship there was a 96.4% sequence similarity and certain taxonomic interspecific differences between both subcultures were confirmed. The various chromatic modifications recorded in cyanobacteria and their ecological consequences are discussed. The results yielded further data on the changes that occur during the cyanobacterial differentiation processes and their genetic stabilization.