scholarly journals Photoinduction of UV-absorbing compounds in Antarctic diatoms and Phaeocystis antarctica

1997 ◽  
Vol 160 ◽  
pp. 13-25 ◽  
Author(s):  
L Riegger ◽  
D Robinson
Keyword(s):  
Phaeocystis Antarctica ◽  
Uv Absorbing Compounds ◽  
Antarctic Diatoms

scholarly journals Response of common buckwheat and Tartary buckwheat from different elevations to selenium treatment

Fagopyrum ◽  
2021 ◽  
Vol 38 (1) ◽  
pp. 15-23
Author(s):  
Aleksandra Golob ◽  
Neja Luzar ◽  
Mateja Germ
Keyword(s):  
Photosystem Ii ◽  
Photochemical Efficiency ◽  
Morphological Characteristics ◽  
Tartary Buckwheat ◽  
Control Group ◽  
Common Buckwheat ◽  
Biochemical Characteristics ◽  
Selenium Treatment ◽  
Uv Absorbing Compounds ◽  
Effective Photochemical Efficiency

Common buckwheat and Tartary buckwheat were grown in Slovenia outdoors at different elevations – 300 m, 600 m and 1180 m a.s.l. Both species were foliarly treated with selenium twice (in the vegetative phase and in the flowering phase). The effects of Se treatment and different growing locations on selected biochemical, physiological and anatomical traits were monitored. In Se treated common buckwheat, amount of chlorophylls was higher in plants from Ljubljana (the lowest elevation – 300 m a.s.l.) than in plants grown in Podbeže (600 m a.s.l.), whereas in control group, plants grown in Ljubljana contained more chlorophylls than plants from Javorje (the highest elevation – 1180 m a.s.l.). In both buckwheat species, Se alone did not affect amount of chlorophylls in any of location. In Se treated common buckwheat plants, the amount of UV absorbing compounds was the highest in plants, grown at the highest elevation. In common buckwheat, Se lowered the number of CaOx in plants, grown in Javorje. Conditions at different elevations, as well as treatments with Se, did not affect potential and effective photochemical efficiency of Photosystem II. Keywords: common buckwheat, Tartary buckwheat, elevation, selenium, morphological characteristics, biochemical characteristics

scholarly journals Mesoscale variability in intact and ghost colonies of Phaeocystis antarctica in the Ross Sea: Distribution and abundance

2017 ◽  
Vol 166 ◽  
pp. 97-107 ◽  
Author(s):  
Walker O. Smith ◽  
Dennis J. McGillicuddy ◽  
Elise B. Olson ◽  
Valery Kosnyrev ◽  
Emily E. Peacock ◽  
...  
Keyword(s):  
Ross Sea ◽  
Mesoscale Variability ◽  
Phaeocystis Antarctica

Phytoplankton community during a coccolithophorid bloom in the Patagonian Shelf: microscopic and high-performance liquid chromatography pigment analyses

2011 ◽  
Vol 92 (1) ◽  
pp. 13-27 ◽  
Author(s):  
Márcio Silva de Souza ◽  
Carlos Rafael Borges Mendes ◽  
Virgínia Maria Tavano Garcia ◽  
Ricardo Pollery ◽  
Vanda Brotas
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Phytoplankton Community ◽  
Sampling Period ◽  
Emiliania Huxleyi ◽  
Patagonian Shelf ◽  
Phaeocystis Antarctica ◽  
Hplc Data ◽  
Phytoplankton Group

We describe the phytoplankton community and biomass during a summer coccolithophorid bloom sampled over the Patagonian shelf (48.5°S–50.5°S). Those phytoplankton species can contribute to the flux of calcium carbonate out of surface waters. Results from both microscope and high-performance liquid chromatography (HPLC) analysis are shown to complement information on the phytoplankton community. From CHEMTAX analysis of HPLC data, the most important organisms and groups identified were the coccolithophorid Emiliania huxleyi, the haptophyte Phaeocystis antarctica, dinoflagellates, diatoms, cryptophytes, prasinophytes and cyanobacteria. Phytoplankton microscope counts were converted into phytoplankton group-specific biovolume estimates. Although some microscope-identified taxa could not be determined by CHEMTAX, e.g. the autotrophic ciliate Myrionecta rubra, cluster analyses from both techniques showed similar results for the main groups. Both Emiliania huxleyi cell concentration and biomass, and the pigment 19′-hexanoyloxyfucoxanthin were the most important biological features during the sampling period. At surface, nitrate was moderately high (0.2–4.2 µM) in coccolithophorid-dominated samples, whereas phosphate (<0.33 µM) and silicate (<1.35 µM) concentrations were low. Among the environmental factors low Si:N ratios were mainly associated with the dominance of E. huxleyi. Competition and probably differential grazing could also promote a coccolithophorid outgrowth over other photoautotrophs during the summer season in the Patagonian shelf.

A Survey of the Distribution of UV-Absorbing Compounds in Aquatic Bryophytes from a Mountain Stream

2004 ◽  
Vol 107 (2) ◽  
pp. 202-208 ◽  
Author(s):  
María Arróniz-Crespo ◽  
Encarnación Núñez-Olivera ◽  
Javier Martínez-Abaigar ◽  
Rafael Tomás
Keyword(s):  
Mountain Stream ◽  
Aquatic Bryophytes ◽  
Uv Absorbing Compounds
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