Abstract
The effects of nutrient supply on photosynthesis (estimated as chlorophyll fluorescence), chlorophyll content, biomass yield and proximate chemical composition of tank cultivated Ulva lactuca L. (Chlorophyta) were evaluated. To assess the effect of nutrient supply on resistance capac- ity against short-term stress, algae grown in high nutrient supply (HNS) fishpond effluents and in low nutrient supply (LNS) oligotrophic seawater were transferred to small vessels with increased irradi- ance of PAR and UV radiation (PAR+UVA and PAR+UVA+UVB using cut-off filters) and increased temperature as compared to culture tanks. Electron transport rate and chlorophyll content were higher in HNS than in LNS algae. Effective quantum yield and chlorophyll content decreased after short-term exposure to high PAR irradiance. Full recovery of photosynthesis in the shade was observed under a moderately higher temperature (Δ+6°C). UVB exposure reduced the negative effect of UVA on photosynthesis and pigment accumulation under temperature stress (Δ+10°C), par- ticularly in HNS algae. Growth under HNS appeared to accelerate acclimation of Ulva lactuca to short-term environmental changes, such as higher temperatures (as in heat waves) and higher UV radiation. Furthermore, nitrogen enrichment reduced the common inhibitory effects of short-term stress such as increased irradiance, UV radiation and temperature on photosynthesis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.