ASSESSING PHYLOGENETIC AFFINITIES AND SPECIES DELIMITATIONS IN KLEBSORMIDIALES (STREPTOPHYTA): NUCLEAR‐ENCODED rDNA PHYLOGENIES AND ITS SECONDARY STRUCTURE MODELS IN KLEBSORMIDIUM, HORMIDIELLA, AND ENTRANSIA¹

Abstract

Nuclear‐encoded SSU, group I intron, and internal transcribed spacer (ITS) rDNA sequences were obtained for 16 strains of green algae representing species of Klebsormidium, Hormidiella attenuata, and Entransia fimbriata (for taxonomic authorities, see Table S1 in the supplementary material). The SSU phylogeny resolved a well‐supported clade Klebsormidiales in the Streptophyta that comprised authentic Klebsormidium isolates described recently in a monograph by G. M. Lokhorst and various strains from culture collections. The H. attenuata and En. fimbriata pair was the sister group of Klebsormidium. Certain isolates from culture collections previously identified as “Klebsormidium” emerged as Trebouxiophyceae. Strains assigned to Koliella, Gloeotila, and Stichococcus previously allied with Klebsormidium because of shared morphological and ultrastructural characteristics also belonged to Trebouxiophyceae. Group I introns inserted at Escherichia coli position 516 were found in K. nitens and SAG strain 384‐1, and at position 1506 in H. attenuata and En. fimbriata. Introns were not observed in other Klebsormidiales. Unambiguous alignment of ITS regions of Klebsormidiales was only possible after thermodynamic folding had predicted eight conserved helical domains. The ITS phylogeny provided support for five of the morphospecies recognized by Lokhorst (K. flaccidum, K. elegans, K. bilatum, K. crenulatum, K. mucosum), but the sequences of K. dissectum, K. fluitans, and K. nitens formed an unresolved clade. The species with the earliest origin in the Klebsormidium phylogeny was K. flaccidum. The incongruence between Lokhorst’s morphology‐based cladograms and the ITS phylogenies demonstrated the need for a critical reappraisal of the taxonomy and the morphological and molecular species concept in Klebsormidium on the basis of a more extensive taxonomic and geographic sampling strategy.

Species composition and diversity of aero-terrestrial algae and cyanobacteria of the Boreč Hill ventaroles.

“…Even if purely morphological data are sufficient for standard ecological studies (where comparison of individual morphotypes illustrates influences of investigated factors), accurate description of the algal flora is essential for potential future comparisons. Since the recent molecular studies have shown a high hidden diversity of aero-terrestrial algae with little morphological differentiation (huss et al 1999, kRienitz et al 2004, sLuiman et al 2008, I place emphasis on a detailed morphological description of the investigated species. Hence, the majority of the investigated species are illustrated .…”

Phylogeny and Molecular Evolution of the Green Algae

“…4). The Klebsormidiophyceae includes the freshwater or terrestrial genera Klebsormidium, Interfilum and Entransia, which form unbranched filaments or sarcinoid packets that produce asexual motile spores with streptophyte characteristics (Cook, 2004b;Sluiman et al, 2008). Diversity and phylogenetic relationships within the Klebsormidiophyceae have been studied by Rindi et al (2008;2011) and Mikhailyuk et al (2008).…”

Novel alpine algae for New Zealand: Klebsormidiales

“…has a convoluted nomenclatural history dating back to the 1800s (reviewed by Lokhorst 1996; see also Novis 2006;Sluiman et al 2008). Briefly, the basionym for the type species of the genus Á K. flaccidum (Ku¨tz.)…”