ACCLIMATION OF PALMARIA PALMATA (RHODOPHYTA) TO LIGHT INTENSITY: COMPARISON BETWEEN ARTIFICIAL AND NATURAL LIGHT FIELDS
Article first published online: 7 JUL 2008
Journal of Phycology
Volume 36, Issue 6, pages 1119–1128, December 2000
How to Cite
Sagert, S. and Schubert, H. (2000), ACCLIMATION OF PALMARIA PALMATA (RHODOPHYTA) TO LIGHT INTENSITY: COMPARISON BETWEEN ARTIFICIAL AND NATURAL LIGHT FIELDS. Journal of Phycology, 36: 1119–1128. doi: 10.1046/j.1529-8817.2000.99156.x
- Issue published online: 7 JUL 2008
- Article first published online: 7 JUL 2008
- 1Received 17 August 1999. Accepted 31 July 2000.
- field investigation;
- light dose;
- light intensity;
- Palmaria palmata;
The acclimation of the photosynthetic apparatus of Palmaria palmata (L.) to light intensity was examined in the field and under laboratory conditions. Algae from 3 different shore levels and from laboratory cultures adapted to 6 different photon flux densities were compared. This was done on the basis of light doses, which were delivered by different light regimes in the field and in the laboratory. Laboratory samples were adjusted to constant photon flux densities between 7 and 569 μmol photons·m−2·s−1 in a 16:8 light:dark photoperiod. Under field conditions the daily amplitudes reached up to approximately 2000 μmol photons·m−2·s−1 within a natural daily light course. Over the course of 14 days the light doses resulting from those different regimes are similar for both treatments. An increasing growth rate per day with increasing light doses was observed in the laboratory. Growth was saturated at 113 mol photons·m−2·14 d−1. Light saturation points (Ek) of photosynthesis increased with increasing light doses for both field and laboratory samples, and all Ek values were significantly related to the growth light dose. A correlation between fresh weight-related lutein content and growth light dose was found for laboratory samples only, whereas the lutein:chlorophyll a (chl a) ratio was strongly correlated with Ek for laboratory and field samples. The content of chl a and phycoerythrin (PE) per fresh weight decreased significantly with increasing light doses under field conditions. Simultaneously, the PE:chl a ratio increased, whereas this ratio was not influenced by laboratory treatments. The correspondence of Ek values for field and laboratory treatments indicated that they were affected mainly by light dose. However, the variability in pigmentation was mainly dependent on temporal variability in light intensity (the amplitude of variations in incident light).