Abstract
The objectives of this study were to determine the phylogenetic relationships of species of Leptosphaeria and Phaeosphaeria and evaluate the phylogenetic significance of morphological characters of the teleomorph, anamorph, and host. Sequences of the entire ITS region, including the 5.8S rDNA, of 59 isolates representing 54 species were analyzed and the phylogeny inferred using parsimony and distance analyses. Isolates grouped into three well-supported clades. The results of this study support the separation of Phaeosphaeria from Leptosphaeria sensu stricto. Leptosphaeria bicolor and the morphologically similar Leptosphaeria taiwanensis formed a separate, well-supported clade. We conclude that peridial wall morphology, anamorph characteristics, and to a lesser extent host, are phylogenetically significant at the generic level. Ascospore and conidial morphology are taxonomically useful at the species level.
The authors would like to thank Patrick Elia for technical assistance and James Plaskowitz for graphics work. We thank Dr. Elwin L. Stewart for his support during this project and Dr. Amy Y. Rossman for logistical support and constructive comments. We sincerely appreciate the insights of Drs. Margaret Barr, Birgitte Volkmann-Kohlmeyer and Jan Kohlmeyer, and Adrian Leuchtmann. Thanks to Dr. David Hibbett for his review of the molecular analyses, Dr. Ove Eriksson for his comments on taxonomic aspects, and Dr. Wendy Unterreiner for her many helpful editorial suggestions. The first author is thankful for funding provided by a Ph.D. fellowship from the Conselho Nacional de Desevolvimento Científico e Tecnológico (RHAE/CNPq), Brazil, which is part of a fungal taxonomy grant coordinated by Dr. José C. Dianese, Univ. de Brasilia (UnB).