Photosynthesis in Codium fragile (Chlorophyta) from a Nova Scotia estuary: responses to desiccation and hyposalinity

摘要: Codium fragile ssp. tomentosoides from Caribou Harbour, an estuarine site in the southern Gulf of St. Lawrence, was extremely tolerant to stresses desiccation and reduced salinity. Photosynthetic responses both rhizomatous erect growth forms were measured using pulse amplitude modulation (PAM) fluorometry chlorophyll a fluorescence determine effective quantum yield (ΦPSII) relative electron transport rate (rETR). After 5 h desiccation, thalli lost 20% their mass, but still showed high levels ΦPSII. Thalli survived for at least 6 freshwater, virtually complete recovery photosynthetic capacity within few hours return full seawater. Immersion 8 psu until 24 treatment period. Combining salinity produced synergistic effect, plants strong even after 86% dehydration reimmersion 16 psu. These results suggest that physiology is highly adapted conditions.