Taxonomic revision of the freshwater cyanobacterium "Phormidium" murrayi = Wilmottia murrayi.

Abstract

Abstract:The cyanobacterial genus Phormidium is polyphyletic, as follows from recent molecular and phenotypic analyses. Several isolated clusters were found also in Antarctic populations (taton et al. 2006(taton et al. , taton et al. 2010(taton et al. , Strunecký et al. 2010b. A few of them have already been described or revised on the generic level (e.g., Phormidesmis, Microcoleus). One of the separate clusters belongs to a group of strains identified traditionally as Phormidium murrayi, described from the Antarctica originally in 1911 as Lyngbya murrayi by W. et G.S.WeSt. We evaluated 23 morphologically similar strains or populations resembling Ph. murrayi from the Antarctica and few other geographical regions; 6 of them were studied by us by molecular methods. Morphological characteristics and 16S rDNA similarity corresponding with typical Ph. murrayi were shared mostly by the specimens from the Antarctica. Molecular analyses confirmed that Ph. murrayi represents a special taxonomic group (on the generic level) inhabiting commonly shallow freshwater classified as a special genus in cyanobacterial taxonomy (Wilmottia gen. nov.) according to the recent "polyphasic approach". The type species of Wilmottia, W. murrayi, was determined up to now to be characteristic for the Antarctica. Other phylogenetically and morphologically similar types from other regions represent possibly different taxa (species) of the same generic unit. The specific status of similar or related strains from other regions should be therefore solved in the future.

Phenotypic and genotypic characteristics ofPhormidium-like cyanobacteria inhabiting microbial mats are correlated with the trophic status of running waters

“…In 16S rDNA analyses, both environmental samples grouped with Phormidium murrayi and Microcoleus glaciei (formerly P. murrayi) in the phylogenetic tree, but in different branches. Previous published studies found a similarly separated Phormidium murrayi clade in phylogenetic analyses, principally from Antarctic habitats (Casamatta et al, 2005;Taton et al, 2006b;Comte et al, 2007;Strunecký et al, 2011) but also from benthic freshwater mats in New Zealand (Heath et al, 2010); the clade was also found in a revision of the genus Microcoleus (Siegesmund et al, 2008). Casamatta et al (2005) reassigned P. murrayi to M. glaciei on the basis of phylogenetic and microscopical analyses and Comte et al (2007) confirmed the separation of P. murrayi from typical Phormidium species (e.g.…”

“…Recently, Strunecký et al (2011) proposed the new genus Wilmottia, with the type species Wilmottia murrayi. Considering that this cyanobacterium was originally described as Lyngbya murrayi, and has subsequently been designated as Phormidium murrayi (Anagnostidis & Komárek, 1988), Microcoleus glaciei (Casamatta et al, 2005) and Wilmottia murrayi (Strunecký et al, 2011), this is clearly a problematic taxon in need of further research. We identified our morphotypes as P. corium on the basis of their separation from 'P.…”

Polyphasic characterization of Trichocoleus desertorum sp. nov. (Pseudanabaenales, Cyanobacteria) from desert soils and phylogenetic placement of the genus Trichocoleus

“…Other studies which have used multiple strains to describe new taxa showed that the 16S rRNA gene sequence similarity can be as low as 98% within one species (cf. Siegesmund et al 2008, Strunecký et al 2011. Most of the T. desertorum strains had similarity values well above this number; however, there were three exceptions with values close to or considerably below 98%.…”

Species concepts and speciation factors in cyanobacteria, with connection to the problems of diversity and classification

“…see Komárek 2010 for review of older works, afterwards e.g. Strunecký et al 2011;Komárek et al 2013;Komárková et al 2013;Dvořák et al 2014a). During the 19th Symposium of the International Society for Cyanophyte Research in 2013, 16 new genera were presented .…”