Polyphasic characterization of eight planktonic Anabaena strains (Cyanobacteria) with reference to the variability of 61 Anabaena populations observed in the field

Abstract

The plasticity of morphological features used for single morphospecies identification was studied under varied experimental conditions (temperature, light, nitrogen, phosphorus) in eight planktonic Anabaena strains. The strains represented all of the morphospecies with coiled trichomes commonly occurring in Central Europe (two strains of A. mendotae & A. sigmoidea complex, two A. lemmermannii strains, two A. flos-aquae strains, and two strains of A. circinalis & A. crassa complex). Significant effects of the growth conditions on vegetative cell dimensions were observed in seven strains, and P concentration was the main influencing factor in most cases (six strains). Significant effect of an environmental factor (P) on akinete morphology was found in only one strain. Experimentally assessed temperature and light growth optima were specific for each strain and were not consistent with the taxonomic affiliation of the strains. Morphologies of the Anabaena strains studied were compared with the field morphologies of 61 Anabaena populations of eight morphospecies observed in the Czech Republic. The range of morphological variability of single strains under the experimental conditions spanned the total variability of the populations of relevant morphospecies observed in the field. Delimitations and proper descriptions of the morphospecies are discussed in the light of partial 16S rRNA gene sequences of the studied strains.

An overview of diversity, occurrence, genetics and toxin production of bloom-forming Dolichospermum (Anabaena) species

“…It has been estimated that about half of the cyanobacterial strains in culture collections have been misidentified (Komá rek and Anagnostidis, 1989). Several studies have cautioned against the over-emphasis on morphological characters for identification and taxonomic classification (Beltran and Neilan, 2000;Rajaniemi et al, 2005a,b;Zapomělová et al, 2007Zapomělová et al, , 2010b.…”

Morphological, biochemical and molecular characterization of Anabaena, Aphanizomenon and Nostoc strains (Cyanobacteria, Nostocales) isolated from Portuguese freshwater habitats

“…On the other hand, the diversity, ecology and genetic heterogeneity among planktonic Anabaenalike and Aphanizomenon-like morphospecies require a deeper characterization, since there is neither a clear phylogenetic nor a morphological separation (Hindák, 2000;Rajaniemi et al, 2005;Stüken et al, 2009). The few existing studies on taxonomy involving planktonic Aphanizomenon and Anabaena strains from Southern Europe were carried out by Pereira et al (2004), Quesada et al (2006) and de Figueiredo et al (2010), while for Northern Europe the number of publications is vast (Hindák, 2000;Lyra et al, 2001;Gugger et al, 2002a;Rajaniemi et al, 2005;Zwart et al, 2005;Komárek & Komárková, 2006;Willame et al, 2006;Rücker et al, 2007;Stüken et al, 2009;Zapomělová et al, 2010).…”

Effects of nutrient availability and temperature on phytoplankton development: a case study from large lakes south of the Alps

“…Though characterised by high variability to temperature adaptation, being typical also of cold environments (e.g., Willén 2003), specific strains of D. lemmermannii show high temperature optima (i.e. between 19 and 26°C; Zapomělová et al 2010) and have, in general, the capability to form huge water blooms in summer stratified conditions and during calm weather. In the epilimnetic layers of the DSL, this taxon generally showed high and abrupt relative increases in abundance at water temperatures higher than 16-17°C.…”