PHYLOGENETIC ANALYSES OF THE BRYOPSIDALES (ULVOPHYCEAE, CHLOROPHYTA) BASED ON RUBISCO LARGE SUBUNIT GENE SEQUENCES¹

Abstract

Current taxonomy of the Bryopsidales recognizes eight families; most of which are further categorized into two suborders, the Bryopsidineae and Halimedineae. This concept was supported by early molecular phylogenetic analyses based on rRNA sequence data, but subsequent cladistic analyses of morphological characters inferred monophyly in only the Halimedineae. These conflicting results prompted the current analysis of 32 taxa from this diverse group of green algae based on plastid-encoded RUBISCO large subunit (rbcL) gene sequences. Results of these analyses suggested that the Halimedineae and Bryopsidineae are distinct monophyletic lineages. The families Bryopsidaceae, Caulerpaceae, Codiaceae, Derbesiaceae, and Halimediaceae were inferred as monophyletic, however the Udoteaceae was inferred as non-monophyletic. The phylogenetic position of two taxa with uncertain subordinal affinity, Dichotomosiphon tuberosus Lawson and Pseudocodium floridanum Dawes & Mathieson, were also inferred. Pseudocodium was consistently placed within the halimedinean clade suggesting its inclusion into this suborder, however familial affinity was not resolved. D. tuberosus was the inferred sister taxon of the Halimedineae based on analyses of rbcL sequence data and thus a possible member of this suborder.

A multi-locus time-calibrated phylogeny of the siphonous green algae

“…DNA amplification followed previously published protocols (Famà et al, 2002;Hanyuda et al, 2000;Karol et al, 2001;Kooistra, 2002;Lam and Zechman, 2006;Olson et al, 2005;Wolf, 1997), with additional primers for amplification of partial sequences of the rbcL gene and the 16S rDNA. A complete overview of the primers used is given in Fig.…”

“…cylindracea) that are known to have profoundly affected the ecology and native biota in areas of introduction. Molecular phylogenetic studies have shown two principal bryopsidalean lineages, both comprising simple as well as complex forms (Lam and Zechman, 2006;Verbruggen et al, 2009;Woolcott et al, 2000).…”

Phylogeny and Molecular Evolution of the Green Algae

“…A single genus, Dichotomosiphon, occurs in freshwater habitats. A phylogeny based on rbcL sequence data (Lam & Zechman, 2006) revealed two main clades, corresponding to the suborders Bryopsidineae and Halimedineae, which are characterized based on differences in thallus morphology, reproduction and plastid types (Hillis-Colinvaux, 1984). Increased gene and taxon sampling improved phylogenetic resolution in these clades and revealed the limestone-boring genus Ostreobium as an early diverging lineage .…”

Species boundaries and phylogenetic relationships within the green algal genus Codium (Bryopsidales) based on plastid DNA sequences

“…Second, the more commonly used outgroup comparison method was applied to infer the root position. Sequences of a Bryopsis species (a sister genus of Codium; Lam and Zechman, 2006) and an Ostreobium species (a more distantly related bryopsidalean genus) were added to the concatenated alignment. The alignment was analyzed with each of the outgroup sequences separately and together using GTR + C + I models as specified in Appendix 5.…”