Abstract
Growth, photosynthesis, dark respiration, chlorophyll a (Chl a) content and dry weight were measured in 2- and 3-year-old plants of Ascoseira mirabilis (Ascoseirales), cultivated in the laboratory under changing daylengths which matched the seasonal variations in the Antarctic. Determinations were made in four thallus regions. Growth of A. mirabilis was seasonal, with higher rates in spring. Parameters such as net photosynthesis (P max), photosynthetic efficiency (α), both measured on a fresh weight (FW) basis, and dry weight content, showed significant age- and size-dependent variations. In contrast, no variations were observed in dark respiration, initial light-saturating point of photosynthesis (I k) and Chl a contents. P max had maximum values close to 16·5 μmol O2 g-1 FW h-1 in 2-year-old plants, whereas in 3-year-old plants maximum values of 8 μmol O2 g-1 FW h-1 were determined. The α-values reached maximum rates of 1.4 and 0.6 μmol O2 g-1 FW h-1 (μmol photons m-2 s-1)-1 in 2- and 3-year-old plants,...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
