Biosystematic studies on the Closterium moniliferum/ehrenbergii complex (Chlorophyta, Conjugatophyceae) in Western Europe. I. Isozyme patterns

Abstract

In the course of a biosystematic investigation into Closterium ehrenbergii and C. moniliferum, 278 clones of these species originating from 17 populations in The Netherlands and England were screened for their electrophoretic banding patterns with respect to the enzymes catalase, shikimate dehydrogenase, malic enzyme, acid phosphatase and isocitrate dehydrogenase. The mean phenotypic identity value (Ī_p ) based on the zymograms between Dutch and English populations of C. ehrenbergii appeared to be considerably lower (Ī_p = 0·20) than between Dutch populations of C. ehrenbergii and C. moniliferum (Ī_p = 0·65). This indicates intrinsic genetic differences between the English and the Dutch populations of C. ehrenbergii investigated and suggests that this typological species should be split into (at least) two biological entities.