caa a22 4500 46909785X CHVBK 20180323133036.0 cr unu---uuuuu 170328e19921001xx s 000 0 eng 10.1007/BF00650323 doi (NATIONALLICENCE)springer-10.1007/BF00650323 Diurnal changes in chlorophyll a fluorescence and carotenoid composition in Opuntia ficus-indica , a CAM plant, and in three C3 species in Portugal during summer [Elektronische Daten] [Klaus Winter, Maria Lesch] Summary: Diurnal changes in chlorophylla fluorescence were determined in four species, differing in life form, in Portugal during the summer of 1989. These includedOpuntia ficus-indica, a CAM plant, andHelianthus annuus, Ficus carica andArbutus unedo, three C3 species. Steady state fluorescence yield,F S, and maximum fluorescence yield,F M′, were determined at different times of the day. Using the model of Genty et al. (1989), the photon use efficiency of photosystem II electron transport,φ e, was calculated from (F M′−F S)/F M′. Diurnal changes in relative rate of non-cyclic electron transport through photosystem II,J e, were derived by multiplyingφ e by the incident photon flux density (PFD). WhenJ e, determined for each species for various points in time throughout the day, was plotted against corresponding values of PFD, the light response curves obtained showed thatJ e was linearly dependent on PFD in low light and approached saturation in high light. The highest values ofJ e were observed inHelianthus annuus, followed byOpuntia ficus-indica, Ficus carica andArbutus unedo. The proportion of the xanthophyll zeaxanthin to total carotenoids, determined around noon, was inversely related to maximum rates ofJ e. Springer-Verlag, 1992 C3, CAM nationallicence Diurnal changes nationallicence Fluorescence nationallicence Photosynthetic electron transport nationallicence Zeaxanthin nationallicence Winter Klaus Lehrstuhl für Botanik II, Mittlerer Dallenbergweg 64, W-8700, Würzburg, Federal Republic of Germany aut Lesch Maria Lehrstuhl für Botanik II, Mittlerer Dallenbergweg 64, W-8700, Würzburg, Federal Republic of Germany aut Oecologia Springer-Verlag 91/4(1992-10-01), 505-510 0029-8549 91:4<505 1992 91 442 https://doi.org/10.1007/BF00650323 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00650323 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Winter Klaus Lehrstuhl für Botanik II, Mittlerer Dallenbergweg 64, W-8700, Würzburg, Federal Republic of Germany aut NATIONALLICENCE 700 1- Lesch Maria Lehrstuhl für Botanik II, Mittlerer Dallenbergweg 64, W-8700, Würzburg, Federal Republic of Germany aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 91/4(1992-10-01), 505-510 0029-8549 91:4<505 1992 91 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer