A REVISED CLASSIFICATION OF THE DICTYOTEAE (DICTYOTALES, PHAEOPHYCEAE) BASED ON rbcL AND 26S RIBOSOMAL DNA SEQUENCE ANALYSES¹

Abstract

Dictyota is a genus of tropical to warm temperate brown algae characterized by parenchymatous, flattened thalli that grow from a single, transversely oriented apical cell. Dictyota is currently distinguished from allied genera of the tribe Dictyoteae (Dilophus, Glossophora, Glossophorella, and Pachydictyon) by the structure of the cortical and medullary layers, as well as the relative abundance of surface proliferations. Even though the traditional classification of the Dictyoteae has repeatedly been criticized in the past, the absence of sound molecular data has so far discouraged any new taxonomic proposals apart from a merger of Dilophus with Dictyota, which has been accepted by only part of the phycological community. Phylogenetic analysis of rbcL gene, partial 26S rDNA sequence, and combined data sets, including four of five generitypes, demonstrates that the traditional classification does not accurately reflect the evolutionary history of the group. None of the genera are resolved as a monophyletic clade. Hence, a merger of Glossophora, Glossophorella, and Pachydictyon in Dictyota is proposed. Two new genera, Canistrocarpus (incorporating D. cervicornis, D. crispata, and D. magneana) and Rugulopteryx (accommodating D. radicans, Dil. suhrii, and Dil. marginata), are proposed. Both genera are supported by molecular indications and a combination of reproductive and vegetative characters. The position of Dil. fastigiatus as a clade sister to Dictyota s.l. and the absence of Dil. gunnianus, the generitype of Dilophus, from the analyses, prevented us from making a more definite statement on the status of the latter genus.

What are and where are the bioactive terpenoids metabolites from Dictyotaceae (Phaeophyceae)

“…Diterpenes of the spatane and seco-spatane types are known from Spatoglossum (S. schmittii and S. howleii), Stoechospermum polypodioides and Rugulopteryx. While the first two genera exhibit growth via a small group of apical cells, Rugulopteryx grows by a single apical cell (De Clerck et al, 2006 ). This genus is distributed over the entire tropical marine world, also reaching some warm temperate regions.…”

“…The Dictyota species that produce secodolastanes and dolastanes were transferred by De Clerck et al (2006) to the genus Canistrocarpus. Although these species also produce dolastanes, these products have chemical characteristics that distinguish them from those of Dictyota origin.…”

Находка Dictyota hauckiana Nizam. (Phaeophycota) на побережье Аравийского моря в Пакистане

“…Но многочисленные круглые в сечении про-лиферации, встречающиеся на поверхности слоевища Glossophora J. Agardh, и иногда даже несущие репродуктивные структуры (De Clerck et al, 2006), не встречаются у D. hauckiana. Короткие цилиндрические волокнистые пролиферации наблюдались у основания вида D. automaria (Børgesen, 1932), который является синонимом D. hauckiana.…”

New records and observations of macroalgae and associated pathogens from the Falkland Islands, Patagonia and Tierra del Fuego

“…For the Dictyota specimens, DNA extractions were performed using CTAB buffer as described by De Clerck et al (2006) and Silberfeld et al (2010). The psbA sequences were generated using the primers psbAF and psbAR reported by Yoon et al (2002).…”

“…Our species is also very different from Dictyota kunthii, originally described from Peru but occurring along most of the Chilean coastline (Malbrán and Hoffmann 1990) and also being present in New Zealand (Nelson 2013). Dictyota kunthii is characterized by terete surface proliferations which formed the basis for its classification in the former genus Glossophora (De Clerck et al 2006). Such proliferations are absent in the Falkland Islands and Tierra del Fuego specimens.…”