Phylogenetic relationships of Cylindrocladium pseudogracile and Cylindrocladium rumohrae with morphologically similar taxa, based on morphology and DNA sequences of internal transcribed spacers and beta-tubulin

Unidentified strains of Cylindrocladium that were baited from soil in the A mazonas state of Brazil or isolated from Adiantum in the Netherlands were e xamined morphologically and analysed phylogenetically in comparison with re ference strains. Phylogenetic trees inferred from the 5.8S subunit and flan king internal transcribed spacers (ITS1 and ITS2) of rDNA, as well as the b eta-tubulin gene, separated species in accordance with their morphological features and characteristics. Although species differences based on ITS seq uences were consistent, there were only a few informative sites available, making it difficult to clearly identify the unknown strains. Better resolut ion in separation of species was achieved from the beta-tubulin data. The s trains baited from soil in Brazil were found to represent two species, name ly Cylindrocladium gracile (Bugnic.) Boesew. and Cylindrocladium pseudograc ile Crous. Morphologically, these two species are similar, except that the latter has slightly narrower, 1(-3)-septate conidia, and produces a Calonec tria teleomorph. Furthermore, the strain from the Netherlands represents Cy lindrocladium rumohrae El-Gholl & Alfenas, a species previously known only from Panama. Results of this study also indicated that the beta-tubulin gen e is phylogenetically more informative than the ITS regions for distinguish ing species of Cylindrocladium.