Accepted: 5 October 1982.
ENVIRONMENTAL FACTORS AND SEXUAL EXPRESSION IN CHLOROCOCCUM ECHINOZYGOTUM (CHLOROPHYCEAE)1
Version of Record online: 24 NOV 2004
Journal of Phycology
Volume 19, Issue 1, pages 57–64, MARCH 1983
How to Cite
O'Kelley, J. C. (1983), ENVIRONMENTAL FACTORS AND SEXUAL EXPRESSION IN CHLOROCOCCUM ECHINOZYGOTUM (CHLOROPHYCEAE). Journal of Phycology, 19: 57–64. doi: 10.1111/j.0022-3646.1983.00057.x
I thank Dr. Francis R. Trainor and Dr. Temd R. Deason for critical reading of the manuscript and Dr. John K. Hardman for helpful discussions during the course of the investigation. Support was provided by a University of Alabama Faculty Research Fellowship.
- Issue online: 24 NOV 2004
- Version of Record online: 24 NOV 2004
- sexual expression;
- zygospore production;
- glutamine synthetase;
- Chlorococcum echinozygotum
Several environmental factors affected total growth and zygospore production in Chlorococcum echinozygotum Starr. The temperature range at which zygospore production occurred was more restricted than the range that supported vegetative growth. Light intensity had little effect upon zygospore formation: gamete production and gamete pairing occurred in darkness. Zygospore production occurred over a wide pH range; bicarbonate had a minor effect upon zygospore formation. Nitrogen concentration was the factor of primary importance. As the level of nitrogen supplied as nitrate, ammonia, urea and asparagine in the medium was increased, zygospore production first increased (over no nitrogen) at low levels and then decreased at high levels. All levels of glutamine supplied reduced zygospore production. A possible way in which nitrogen concentration in the medium and sexual expression are linked is discussed.