Chlorella is one of the archetypical forms of coccoid green algae and one of the best-studied phototrophic eukaryotes. However, its systematics remains enigmatic due to conflicts between morphological and molecular phylogenetic approaches. The sequences of the 18S ribosomal RNA gene of nine strains of Chlorella and related taxa, and the ITS2 region of 17 strains of Chlorellaceae were determined and included in phylogenetic analyses. The secondary structure of the ITS2 region of C. vulgaris was compared to that of Parachlorella beijerinckii. All phylogenetic analyses showed that the Chlorellaceae form a clade within the Trebouxiophyceae. The Chlorellaceae studied here are divided into two sister groups: (1) the Parachlorella-clade with Parachlorella beijerinckii gen. et sp. nov. and P. kessleri comb. nov. as well as Diclosler acuatus and Closteriopsis acicularis; and (2) the Chlorella-clade including the ‘true’ spherical Chlorella species C. vulgaris, C. lobophora and C.sorokiniana. The latter are...

Krienitz L., Bock C., Dadheech P.K. and Pröschold T. 2011. Taxonomic reassessment of the genus Mychonastes (Chlorophyceae, Chlorophyta) including the description of eight new species. Phycologia 50...

Hot springs and saline-alkaline lakes of East Africa are extreme habitats regarding temperature, or salinity and pH, respectively. This study examine