Phylogenetic relationships of Pestalotiopsis and allied genera inferred from ribosomal DNA sequences and morphological characters.

The taxonomy of the coelomycetous fungus Pestalotiopsis and other closely related genera based on morphological characters has been equivocal. To gain insight in the phylogenetic relationships of Pestalotiopsis and its allies, part of the large subunit (28S) ribosomal DNA region was examined and compared with existing morphological information. Phylogenetic analyses were conducted using parsimony, distance, and likelihood criteria. Results of the analyses showed that Bartalinia, Pestalotiopsis, Seimatosporium, and Seiridium represent distinct monophyletic groups with high bootstrap support. However, Truncatella species are paraphyletic with Bartalinia, sharing a common ancestor. Pestalotia species sequenced clustered together with Pestalotiopsis. These genera should be recognized as distinct natural groups except for Monochaetia and Discosia, which need to be further resolved. Tree topologies are generally in concordance with previous morphological hypotheses, most notably the placement of all Pestalotia species, except the type P. pezizoides, in Pestalotiopsis. Well-supported clades corresponding to groupings based on conidial morphology were resolved and the relative importance of morphological characters for generic delimitation is discussed. Molecular data also provide further evidence to support the association of these coelomycetes with the Amphisphaeriaceae.