New genus Koliellopsis (Trebouxiophyceae, Chlorophyta): its phylogenetic position inferred from ultrastructure and nuclear ribosomal DNA sequences

Abstract

Koliellopsis inundata Lokhorst gen. & sp. nov. (Trebouxiophyceae) is described from periodically flooded agricultural fields in the borderland of Belgium and the Netherlands. This new, unbranched, filamentous alga is typified by relatively long vegetative cells, which have a bilobed, laminate chloroplast with a nucleus positioned in its median constriction. Its filaments lack a distinct basal-distal differentiation and both ends terminate in about equally shaped, rounded or, more often (slightly) tapering cells. Despite its semiterrestrial occurrence the new alga does not attach to hard substrate, presumably owing to the lack of end cells to produce mucilage and to function as a holdfast. The systematic position of Koliellopsis among the green algae is inferred from ultrastructural examinations of the cell division patterns and from phylogenetic analyses of partial 18S rRNA gene sequences.

PHYLOGENETIC RELATIONSHIPS WITHIN THE STYLONEMATALES (STYLONEMATOPHYCEAE, RHODOPHYTA): BIOGEOGRAPHIC PATTERNS DO NOT APPLY TO STYLONEMA ALSIDII1

“…2006, this paper). The variation in habit (e.g., filaments and unicells) is similar to groups being discovered in the Chlorophyta where habit and other characters are not good predictors of relationships (Lokhorst et al. 2004).…”

Mother Cell Wall Cleavage during Filament Formation in <i>Stichococcus bacillaris</i> (Trebouxiophyceae, Chlorophyta)

“…Neustupa et al (2007) also reported that the Stichococcus jenerensis CAUP J 1302 strain grows mostly as unicells or twocelled short filaments, and longer filaments comprising 4 to 10 (rarely 20) cells were regularly observed on agar solidified BBM (Bold s Basal Medium). Recently, analyses of 18S rRNA sequences indicated that Stichococcus belongs to the Trebouxiophyceae (Friedl and O Kelly 2002, Karsten et al 2005, Katana et al 2001, Lokhorst et al 2004. Moreover, Karsten et al (2005) showed that the genus Stichococcus is a member of the Prasiola Meneghini clade in the 18S rRNA tree.…”