Premium
PHYLOGENY OF THE HYDRODICTYACEAE (CHLOROPHYCEAE): INFERENCES FROM rDNA DATA 1
Author(s) -
Buchheim Mark,
Buchheim Julie,
Carlson Tracy,
Braband Anke,
Hepperle Dominik,
Krienitz Lothar,
Wolf Matthias,
Hegewald Eberhard
Publication year - 2005
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.2005.00129.x
Subject(s) - biology , monophyly , phylogenetics , ribosomal dna , phylogenetic tree , lineage (genetic) , autapomorphy , evolutionary biology , internal transcribed spacer , chlorophyceae , botany , zoology , genetics , algae , chlorophyta , gene , clade
The hydrodictyacean green algal lineage has been the focus of much research due to the fossil record of at least some members, their ornamented cell walls, and their distinctive reproductive strategies. The phylogeny of the family was, until recently, exclusively morphology based. This investigation examines hydrodictyacean isolates from several culture collections, focusing on sequences from ribosomal data: 18S rDNA, 26S rDNA (partial), and internal transcribed spacer (ITS)‐2 data. Results from phylogenetic analyses of independent and combined data matrices support the Hydrodictyaceae as a monophyletic lineage that includes isolates of Chlorotetraedron , Hydrodictyon , Pediastrum, Sorastrum , and Tetraedron . Phylogenetic analyses of rDNA data indicate that the three‐dimensional coenobium of Hydrodictyon is evolutionarily distinct from the three‐dimensional coenobium of Sorastrum . The more robust aspects of the ITS‐2 data corroborate the 18S+26S rDNA topology and provide a structural autapomorphy for the Hydrodictyaceae and Neochloridaceae, that is, an abridgment of helix IV in the secondary structure. The rDNA data do not support monophyly of Pediastrum but rather suggest the existence of four additional hydrodictyacean genera: Monactinus, Parapediastrum, Pseudopediastrum , and Stauridium .