Original paper

Sind Scenedesmus obtusiusculus Chod. und Scenedesmus obliquus (Turp.) Kütz. (Chlorophyta, Chlorococcales) verschiedene Arten?

[Are Scenedesmus obtusiusculus Chod. and Scenedesmus obliquus (Turp.) Kütz. (Chlorophyta, Chlorococcales) different species?]

Dzhambazov, Balik; Belkinova, Detelina; Mladenov, Rumen

Abstract

The taxonomical status of the species with similar morphological characters Scenedesmus obtusiusculus Chod. and Scenedesmus obliquus (Turp.) Kütz. has been discussed by karyotypic analysis. On the basis of a detailed morphological and morphometrical chromosomal analysis it was found that the karyotype of S. obtusiusculus (n = 5) is symmetrical. It consists of three large metacentric and two large submetacentric chromosomes. The karyotype of S. obliquus (n = 4) is asymmetrical. It consists of two large submetacentric and two small metacentric chromosomes. The general chromosomal formulae of both species as well as the total average metaphase length of their haploid set were presented. The data from the comparative analysis of some Scenedesmus species showed a proportional dependency between the average length of the cell and the total average metaphase length of their haploid set. The results confirmed that S. obtusiusculus and S. obliquus are two separate biological species.

Keywords

karyotypes • Scenedesmus taxonomy • clonal cultures