Open AccessEffects of artificial and solar UV‐B radiation on the gravitactic orientation of the dinoflagellate, Peridinium gatunense
Author(s) -
Häder DonatP.,
Liu ShiMei
Publication year - 1990
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1990.tb03957.x
Subject(s) - dinoflagellate , radiation , physics , fluence , irradiation , orientation (vector space) , optics , astrophysics , biology , botany , geometry , mathematics , nuclear physics
The effects of artificial and solar UV‐B radiation on the gravitactic (formerly called geotactic) orientation of the freshwater dinoflagellate Peridinium gatunense were measured under artificial UV‐B radiation and in a temperature‐controlled growth chamber under solar radiation in Portugal. Circular histograms of gravitaxis show the impairement of orientation after UV irradiation. The degree of orientation, quantified using the Rayleigh test and top quadrant summation, decreased as the exposure time to the radiation prolonged. The effects of artifical UV‐B radiation on orientation are stronger than those of solar radiation, probably because the radiation source emits higher fluence rates below 300 nm than found in solar radiation. After UV radiation, the gravitactic orientation under artificially increased acceleration at 2 g was drastically affected.