Diel periodicity of spore release from the kelp Nereocystis luetkeana (Mertens) Postels et Ruprecht

• Published in: Journal of experimental marine biology and ecology 1989, Vol.134 (2), p.117-127
• Main Authors: Amsler, Charles D., Neushul, Michael
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Demecology; Dispersal; Fundamental and applied biological sciences. Psychology; Kelp; Macroalga; Nereocystis; Periodicity; Plants and fungi; Spore
• ISSN: 0022-0981; 1879-1697
• DOI: 10.1016/0022-0981(90)90104-K

Sorus abscission and associated spore release were monitored in the laboratory from Nereocystis luetkeana (Mertens) Postels et Ruprecht plants collected at three sites in central California, U.S.A. Nearly 80% of the sori were released in the interval between 2 h before sunrise and 4 h after sunrise. This dawn abscission pattern was observed on each day and from plants collected at all sites. Short-term observations in nature confirmed the pattern. Sori from individual plants were usually abscised at intervals of 2–4 days. Sori often began releasing spores before abscission and, in nature, probably continue to release spores as they are falling through the water column. > 50% of the spores released from abscised sori in the laboratory were released in the 1st h after abscission at a mean rate two to four orders of magnitude higher than previously reported for related macroalgae; nearly 95% had been released within 4 h. This sorus abscission-spore release mechanism is probably adaptive in maximizing the photosynthetic potential of the spores, maximizing the potential dispersal of some of the spores, and ensuring that a proportion of the spores will be retained near the parents.