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NUTRITIONAL REQUIREMENTS OF THE SUBMERGED ANGIO-SPERM 'RUPPIA MARITIMA' IN ALGAE-FREE CULTURE
Citation:
Thursby, G. NUTRITIONAL REQUIREMENTS OF THE SUBMERGED ANGIO-SPERM 'RUPPIA MARITIMA' IN ALGAE-FREE CULTURE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-84/047 (NTIS PB84222660).
Description:
Ruppia maritima has the potential to become a model laboratory organism for studies with submerged aquatic vascular plants. The present study demonstrated that algae-free R. maritima grew well in a defined medium without sediment. Growth was a linear response to photon flux density over the range of light tested. Vitamins may be a necessary addition in artificial seawater. Trace metals caused little or no increase in growth during short-term (3 wk) growth studies, but appear to be required for long-term cultivation. Iron also caused no increase in growth, at the concentrations tested, but plants were greener in 1.46 micrometers M iron. A nitrate concentration of 110 micrometers M and a phosphate concentration of 2.3 micrometers M were sufficient for maximum growth. However, 4.5 micrometers M phosphate eliminated occasional CaCO3 precipitation in stock cultures. Critical tissue nitrogen content was between 2.5 and 3.0%, and critical phosphorus content between 0.25 and 0.35%. A comparison with field data suggests that R. maritima was deficient in both nitrogen and phosphorus during much of the summer.