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Physiological ecology of photosynthesis in P rasiola stipitata ( T rebouxiophyceae) from the B ay of F undy, C anada
Author(s) -
Kang Eun Ju,
Scrosati Ricardo A.,
Garbary David J.
Publication year - 2013
Publication title -
phycological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.438
H-Index - 44
eISSN - 1440-1835
pISSN - 1322-0829
DOI - 10.1111/pre.12017
Subject(s) - desiccation , thallus , photosynthesis , biology , population , chlorophyll fluorescence , botany , quantum yield , dehydration , photosystem ii , algae , irradiance , horticulture , fluorescence , physics , biochemistry , sociology , demography , quantum mechanics
Summary The physiological ecology of P rasiola stipitata was examined in situ from two supralittoral sites in the B ay of F undy ( N ova S cotian, C anada) during N ovember 2011, when the population was undergoing major expansion. Photosynthetic parameters (effective quantum yield, Φ PSII , maximum quantum yield, F v / F m , and relative electron transport rate, rETR ) were evaluated using chlorophyll fluorescence of PSII . A largely shaded and continuously moist population showed no change in Φ PSII from one hour after sunrise to sunset in which natural irradiance varied between 3 and 300 μmol photons m −2 s −1 . High irradiance (up to 1800 μmol photons m −2 s −1 ) had no apparent negative impacts on either quantum yield or rETR , but high desiccation in the field reduced quantum yield to almost zero. When thalli were brought into the laboratory, no change in F v / F m was observed up to 60% dehydration; however, there was a steep decline in F v / F m between 60% and 85% dehydration. Thalli showed complete recovery of F v / F m within one hour of reimmersion in seawater after 2 days of desiccation. After 15 days of desiccation full recovery required 24 h and after 30 days of desiccation thalli showed only partial recovery. These observations confirm the adaptation to photosynthesis in high irradiances and the rapid recovery following extreme desiccation observed in other P rasiola species.