title: Classification of crucigenoid algae: phylogenetic position of the reinstated genus Lemmermannia, Tetrastrum spp. Crucigenia tetrapedia, and C. lauterbornii (Trebouxiophyceae, Chlorophyta)(1).
abstract: The subfamily Crucigenioideae was traditionally classified within the well-characterized family Scenedesmaceae (Chlorophyceae). Several morpho-logical revisions and questionable taxonomic changes hampered the correct classification of crucigenoid species resulting in a high number of synonymous genera. We used a molecular approach to determine the phylogenetic position of several Tetrastrum and Crucigenia species. The molecular results were correlated with morphological and ontogenetic characters. Phylogenetic analyses of the SSU rDNA gene resolved the position of Tetrastrum heteracanthum and T. staurogeniaeforme as a new lineage within the Oocystis clade of the Trebouxiophyceae. Crucigenia tetrapedia, T. triangulare, T. punctatum, and T. komarekii were shown to be closely related to Botryococcus (Trebouxiophyceae) and were transferred to Lemmer-mannia. Crucigenia lauterbornii was not closely related to the other Crucigenia strains, but was recovered within the Chlorella clade of the Trebouxiophyceae.
authors.affiliation: Department of General Botany, Faculty of Biology, University Duisburg-Essen, Universitätsstr. 5, Essen, D-45141, Germany.|Department of Limnology of Stratified Lakes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhütte 2, Stechlin-Neuglobsow, D-16775, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Bock
authors.affiliation: SOA Key Laboratory for Polar Science, Polar Research Institute of China, Jin Qiao Road, Shanghai, 200136, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.affiliation: Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Königin-Luise-Str. 6-8, Berlin, 14195, Germany.
authors.forename: Wolf-Henning
authors.initials: WH
authors.lastname: Kusber
authors.affiliation: Grüner Weg, Niederzier, D-52382, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Hegewald
authors.affiliation: Department of Botany, Faculty of Science, University of South Bohemia, Ceske Budejovice, 37005, Czech Republic.
authors.forename: Marie
authors.initials: M
authors.lastname: Pažoutová
authors.affiliation: Department of Limnology of Stratified Lakes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhütte 2, Stechlin-Neuglobsow, D-16775, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Krienitz
keywords: Chlorella; Crucigenia; ITS; Lemmermannia; SSU; Scenedesmaceae; Tetrastrum; Trebouxiophyceae; phylogeny; taxonomy