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Effects of UV-A Radiation on Desmodesmus armatus: Changes in Growth Rate, Pigment Content and Morphological Appearance

✍ Scribed by Károly Pálffy; Lajos Vörös


Publisher
John Wiley and Sons
Year
2006
Tongue
English
Weight
180 KB
Volume
91
Category
Article
ISSN
1434-2944

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✦ Synopsis


Abstract

Laboratory cultures of Desmodesmus armatus (R. Chod.) Hegew. were grown under different levels of photosynthetically active radiation (PAR) supplemented with 3.75 mW · cm^–2^ UV‐A radiation. Growth rate was monitored daily, chlorophyl‐a concentration, total carotenoid content, cell number and the relative abundance of different coenobial forms was determined at the end of each experiment. Exposure to UV‐A radiation resulted in an increasing inhibition of growth towards higher PAR levels, reaching 100% at 400 µmol · m^–2^ · s^–1^. Cellular carotenoid content was higher in the presence of UV‐A radiation, on the other hand no differences were observed in cellular chlorophyll‐a concentration. UV‐A radiation also induced changes in coenobium formation with a decreasing proportion of 4‐celled coenobia and an increase in the abundance of 2‐celled and teratologic coenobia, suggesting that high intensity UV‐A radiation may influence cell cycle events or morphology development. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)