Effect of nitrogen supply on nitrogen content and growth rate of juvenile Macrocystis pyrifera (phaeophyta) sporophytes

Journal Article · Mon Dec 01 04:00:00 EST 1980 · J. Phycol.; (United States)

DOI:https://doi.org/10.1111/j.0022-3646.1980.00577.x· OSTI ID:6771270

Wheeler, P A; North, W J

The effect of nitrogen supply on nitrogen content and growth rate of juvenile Macrocytis pyrifera (L.) C. A. Agardh sporophytes was studied in two types of experiments: growth in continuously flowing mixtures of deep (nutrient-rich) and surface (nutrient-poor) seawater, and growth in batch cultures with alternate 7 to 10 day periods in deep and surface water. In the continuous flow experiments, the nitrogen content of the plants increased with the increased concentration of nitrate in the seawater. In the batch culture experiments, a lag period of 3 to 7 days often occurred before changes in the nitrogen supply were reflected in corresponding changes in the nitrogen content of the plants. Growth rates were a linear function of tissue nitrogen which varied between 1 to 3% dry weight. Saturation of growth rate as a function of tissue nitrogen did not occur, although tissue nitrogen levels did saturate as a function of external nitrate supply. Juvenile M. pyrifera sporophytes do not appear to store nitrogen. Total nitrogen varies from 1 to 6% dry weight in Laminariales and Fucales, but only some species of Laminaria appear to accumulate large pools of surplus nitrogen.

• Research Organization: California Inst. of Tech., Pasadena
• OSTI ID: 6771270
• Journal Information: J. Phycol.; (United States), Journal Name: J. Phycol.; (United States) Vol. 16:4; ISSN JPYLA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
AQUATIC ORGANISMS
BIOLOGICAL EFFECTS
BUILDUP
ELEMENTS
GAMETOGENESIS
GROWTH
HYDROGEN COMPOUNDS
METABOLISM
NITROGEN
NONMETALS
OXYGEN COMPOUNDS
PLANT GROWTH
PLANT TISSUES
PLANTS
QUANTITY RATIO
SEAWATER
SEAWEEDS
SPORES
TIME DEPENDENCE
WATER
WEIGHT