Optima and limits of primary photosynthetic production of three lichen phycobionts of the genus Trebouxia
| Authors | |
|---|---|
| Year of publication | 2009 |
| Type | Article in Periodical |
| Magazine / Source | Phycologia |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.ec-inc.co.jp/ipc9/ |
| Field | Botany |
| Keywords | photobiont; environmental extremes; temperature; irradiance; toxic metals; chlorophyll fluorescence |
| Description | Lichens are known for their ability to survive in extreme environments. A photobiont, considered as key element in sensitivity of whole organism, belongs mostly to the genus Trebouxia. In the study, three lichen photobiont species with different chloroplast morphology were investigated to characterize interspecific differences. The aim was to assess the effects of limiting conditions of temperature, light and presence of heavy metals (Cu and Cd)on primary production and the growth. Within the experiments, techniques of cultivation of algae in crossed gradients of temperature and irradiance were used. Growth differences and production of colonies were analyzed by photogrammetrical image analysis and determination of chlorophylls and carotenoids contents. The parameters of biomass growth as well as the parameters of CFI showed that temperature and light intensity optima for growth and photosynthetic activity of Trebouxia photobiont species lie between 16 to 18 deg.C and irradiances less than 50 umol.m-2.s-1. Limitation of growth and primary production of studied strains became apparent at the temperatures above 28 deg.C. At the tested light intensities above 200 umol.m-2.s-1, there were found signs of photoinhibition of photosynthesis. |
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