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Marine Plankton Algae Grown with Light‐Dark Cycles. I. Coccolithus huxleyi
Author(s) -
Paasche E.
Publication year - 1967
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1967.tb08382.x
Subject(s) - algae , photoperiodism , light intensity , biology , plankton , botany , chlorophyll a , ecology , physics , optics
A description is given of an apparatus for semi‐continuous cultivation of unicellular algae under various combinations of light intensity, temperature and daylength (photoperiod). In this apparatus growth of the coccolithophorid Coccolithus huxleyi was limited by light intensities below 0.05 cal/cm 2 min regardless of daylength. Growth was retarded by daylengths shorter than 16 hours out of a total of 24 hours of light plus dark. The temperature optimum for growth was about 20 C and showed little variation with daylength. The content of chlorophyll a varied between 2 and 15 mg per ml cell volume and was greatest under low light intensities, short daylengths and high temperatures. Cultures were synchronised by four different combinations of light intensity and daylength. In all four cases, cell division was restricted to 6 out of 24 hours. Synchronised cell division took place in the dark but its timing bore no simple relationship to the onset or termination of illumination.