Phylogenetic relationships in Interfilum and Klebsormidium (Klebsormidiophyceae, Streptophyta).

Members of the genus Klebsormidium have cosmopolitan distribution and occur in a very wide range of freshwater and terrestrial habitats. Due to its simple filamentous morphology, this genus represents a taxonomically and systematically complex taxon in which phylogenetic relationships are still poorly understood. The phylogeny of Klebsormidium and closely related taxa was investigated using new ITS rRNA and rbcL sequences generated from 75 strains (isolated from field samples or obtained from culture collections).

Highly differentiated populations of the freshwater diatom Sellaphora capitata suggest limited dispersal and opportunities for allopatric speciation.

The diversities and distributions of diatoms are much more complex than was ever imagined. To understand the underlying mechanisms, research must focus on evolutionary processes occurring at a population level and employ sufficiently informative molecular markers. Using ten microsatellites and ITS rDNA sequence data, we investigated the genetic structure of populations of the benthic freshwater diatom Sellaphora capitata (until 2004 a cryptic entity within the S.

NEW STREPTOPHYTE GREEN ALGAE FROM TERRESTRIAL HABITATS AND AN ASSESSMENT OF THE GENUS INTERFILUM (KLEBSORMIDIOPHYCEAE, STREPTOPHYTA)(1).

Sarcinoid aeroterrestrial green algae were isolated from three arid locations in Ukraine and the Czech Republic. Although gross morphology suggested an affinity with Desmococcus (for taxonomic authorities, see Table S1 in the supplementary material), the cellular morphological characteristics were reminiscent of those of Geminella terricola. However, the presence of a complex of ultrastructural features indicated that these isolates were members of the streptophyte lineage in the green plants.

ASSESSING PHYLOGENETIC AFFINITIES AND SPECIES DELIMITATIONS IN KLEBSORMIDIALES (STREPTOPHYTA): NUCLEAR-ENCODED rDNA PHYLOGENIES AND ITS SECONDARY STRUCTURE MODELS IN KLEBSORMIDIUM, HORMIDIELLA, AND ENTRANSIA(1).

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.