Phylogeny of Chaetosphaeria and its anamorphs based on morphological and molecular data

Abstract

In order to more fully elucidate the phylogenetic relationships of the lignicolous, pyrenomycetous genus Chaetosphaeria and its anamorphs and reveal the most reliable molecular data set we sequenced a portion of the large nuclear ribosomal RNA gene (LSU rDNA) and the complete ITS region (ITS1, the 5.8S rRNA gene and ITS2) of 25 members of the Chaetosphaeriaceae including Porosphaerella cordanophora, Striatosphaeria codinaeophora, species of Chaetosphaeria and Melanopsammella, and representatives of eight of the eleven of their anamorph genera. Phylogenetic analyses were performed on four different data sets. The phylogeny inferred from the LSU rDNA sequence data showed two main groups, each with two subgroups, within the monophyletic Chaetosphaeriaceae. These subgroups are easily identified by morphological features of anamorphs and teleomorphs and serve as a background to subdivide the Chaetosphaeria species in to two, respectively, two and four natural groups of taxa. Two sexual species currently referred to Chaetosphaeria and two related asexual species grouped with Hypocreales and Microascales, respectively. Knoxdaviesia is relegated to synonymy with Custingophora. The morphology-based classification of Chaetosphaeria is compared with results from analyses of molecular data. The taxonomic value of morphological characters observed in teleomorphs and dematiaceous hyphomycetous anamorphs is discussed in the light of the results of these analyses.