Phenotypic plasticity in Scenedesmus communis Hegew. (Chlorophyceae). II. Examples of algal cyclo- and noncyclomorphosis

• Published in: American journal of botany Vol. 78; no. 1; pp. 37 - 52
• Main Authors: Egan, P.F, Trainor, F.R
• Format: Journal Article
• Language: English
• Published: Ithaca, NY American Botanical Society 01-01-1991; Botanical Society of America; Botanical Society of America, Inc
• Subjects: Algae; ANATOMIA DE LA PLANTA; ANATOMIE VEGETALE; Batch cell culture techniques; Biological and medical sciences; Biological taxonomies; Botany; Cell walls; Cells; CHLOROPHYCEAE; Classification; ENVIRONMENTAL FACTORS; FACTEUR DU MILIEU; FACTORES AMBIENTALES; FENOTIPOS; Fundamental and applied biological sciences. Psychology; GENETIC VARIATION; Hydrobiology; MORFOGENESIS; MORPHOGENESE; MORPHOGENESIS; PHENOTYPE; PHENOTYPES; Phenotypic plasticity; Phycology; PLANT ANATOMY; Plant cytology, morphology, systematics, chorology and evolution; Plant growth; POLIMORFISMO; POLYMORPHISM; POLYMORPHISME; SCENEDESMUS KOMAREKII; SCENEDESMUS SUBSPICATUS; Taxa; Thallophyta; ULTRASTRUCTURE; VARIACION GENETICA; VARIATION GENETIQUE; Life cycle; Scanning electron microscopy; Phenotype; Taxonomy; Ultrastructure; Algae; Morphology; Chlorophycophyta; Environmental factor; Thallophyta
• ISSN: 0002-9122; 1537-2197
• DOI: 10.1002/j.1537-2197.1991.tb12569.x

A new dimension to the well-known phenotypic plasticity in Scenedesmus is presented. Large colony type Scenedesmus communis Hegew. reproduced in a typical fashion in batch culture in standard media but produced small colonies (SCT) resembling S komarekii Hegew. and S. subspicatus Chod. at low cell densities in dilute media. Highest frequency of production occurred after cells had been pretreated in a concentrated (inorganic nutrients) medium. Examples of both cyclic and noncyclic behavior in the life history of Scenedesmus are presented. The noncyclic behavior resembles previous reports on induced heritable changes in flax and tobacco due to different treatment applications of fertilizers. An analysis of gross morphological features using scanning electron microscopy showed that isolated strain SCT1 was similar to S. komarekii (strain UTEX 1236) and isolated strain SCT2 was similar to S. subspicatus (strain UTEX 1358). Growth and morphological expression of the induced SCT strains were highly similar to those of the respective UTEX species. The current state of taxonomy and the implications of phenotypic plasticity on taxonomy in Scenedesmus are discussed.