A MOLECULAR AND MORPHOLOGICAL ANALYSIS OF MICROTHAMNION (CHLOROPHYTA,MICROTHAMNIALES)

Genomic relationships of the microphytic green alga Microthamnion isol ated from a wide range of habitats in different geographical locations were examined by means of restriction enzyme analysis of amplified nu clear-encoded 18S rRNA genes. Restriction fragment patterns obtained u sing six endonucleases were identical in the 29 clonal strains investi gated. A recent review (JOHN & JOHNSON 1987) of morphological variatio n in the genus has concluded that it is either a complex of at least t wo species (separated on dimensional characters), or a single very pol ymorphic species. The consensus between the analysis and the morpholog ical data supports the view that Microthamnion is monospecific.