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| Format: | Artículo científico |
| Language: | en |
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Universidad Autónoma de Baja California
2015
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| Online Access: | https://www.redalyc.org/articulo.oa?id=48039202002 |
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Table of Contents:
- Effect of irradiance and nitrate levels on the relationship bet ween gross photosynthesis and electron tra nsport rate in the seagrass Cymodocea nodosa Alejandro Cabello-Pasini Roberto T Abdala-Díaz Víctor Macías-Carranza Félix L Figueroa Ciencias de la Tierra nitrate seagrass phot osynthesis Cymodocea nodosa electron transport rate The relationship between gro ss photosynthesis (GPS) and electr on transport rate (ETR) in marine algae has been shown to vary as a function of irradiance; howeve r, little is known about the ef fect of nutrients on the this rel ationship in seagrasses. The o bjective of this study was to evaluate the effect of ni trate concentration on the GPS (measured as O 2 evolution) vs ETR (estimated by fluorescence quenching analysis) relationship of the seagrass Cymodocea nodosa from the Spanish Mediterranean Sea. Carbon levels in the tissu e increased 6.5% when nitrate in the culture medium augmented from 0 to 100 M. Nitrogen in the tissue, however, increased more than 60% whe n nitrate concentration in the medium reached 100 M. Chlorophyll a + b levels increased approximately 30%, while absorptance augmente d 15% when nitrate increased from 0 to 100 M. In general, maximum oxygenic photosynthesis and maximum ETR values increased when nitrate in the medium increased. The relationship between GPS and ETR did not show a linear response at low nit rate levels and high irradianc es. In contrast, a linear relationship was observ ed at nitrate levels above 50 M, even at high irradiances. The results from this study sugges t that the lack of correlation between ETR and GPS is the result of low nitrogen l evels in the tissue of marine macrophytes. They also suggest th at seasonal fluctuations in nitrate levels or nitrogen pulses, such as thos e observed during upwelling events , may affect the relationship between GPS and ETR in C. nodosa or other marine macrophytes. 2015 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48039202002 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.2 Vol.41