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Factors affecting akinete differentiation in Cylindrospermopsis raciborskii (Nostocales, Cyanobacteria)
Author(s) -
MOORE DAVID,
O'DONOHUE MARK,
GARNETT CORINNE,
CRITCHLEY CHRISTA,
SHAW GLEN
Publication year - 2005
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/j.1365-2427.2004.01324.x
Subject(s) - cylindrospermopsis raciborskii , biology , cyanobacteria , light intensity , botany , phytoplankton , ecology , physics , nutrient , bacteria , genetics , optics
Summary 1. Cylindrospermopsis raciborskii is a potentially toxic freshwater cyanobacterium which can produce akinetes (reproductive spores) that on germinating can contribute to future populations. To further understand factors controlling the formation of these specialised cells, the effects of diurnal temperature fluctuations (magnitude and frequency), in combination with different light intensities and phosphorus concentrations were investigated under laboratory conditions. 2. Akinete differentiation was affected by the frequency of temperature fluctuations. Maximum akinete concentrations were observed in cultures that experienced multiple diurnal temperature fluctuations. 3. Akinete concentrations increased with increasing magnitude of temperature fluctuation. A maximum akinete concentration was achieved under multiple diurnal temperature fluctuations with a magnitude of 10 °C (25 °C to 15 °C). 4. A fourfold increase in light intensity (25–100 μ mol m −2 s −1 ) resulted in an approximate 14‐fold increase in akinete concentration. 5. High filterable reactive phosphorus (FRP) concentrations (>70 μ g L −1 ) in the medium, combined with a multiple diurnal temperature fluctuation of 10 °C, supported the development of the highest akinete concentration.