Phylogenetic evaluation of species nomenclature of Pestalotiopsis in relation to host association

DNA data from a number of Pestalotiopsis isolates were analysed to investigate whether isolates from the same host are phylogenetically related. The validity of naming species of Pestalotiopsis based on host association was investigated. Regions of the ITS and 5.8S of the rDNA gene were amplified from genomic DNA using PCR. DNA characters were analysed using maximum parsimony (weighted and unweighted) and maximum likelihood criteria. Isolates from the same host were not phylogenetically closely related. A close phylogenetic relationship between isolates possessing similar morphological characters was apparent. Results indicate that the naming of species based on host association is unwise and dispute the assumption that species are host-specific. When new Pestalotiopsis species are described, morphological characters should be taken into account rather than host association. The implications of the results on fungal biodiversity studies are discussed.