A preliminary overview of the Diaporthales based on large subunit nuclear ribosomal DNA sequences

Abstract

The ascomycete order Diaporthales includes a number of plant pathogenic fungi such as Cryphonectria parasitica, the chestnut blight fungus, as well as many asexually reproducing fungi without known sexual states. Relationships among genera in the Diaporthales were evaluated as a basis for the recognition of families and to provide a taxonomic framework for the asexually reproducing diaporthalean fungi. Phylogenetic relationships were determined based on analyses of large subunit (LSU) nuclear ribosomal DNA (nrDNA) sequences. Within the Diaporthales 82 sequences representing 69 taxa were analyzed. Results suggest the presence of at least six major lineages within the Diaporthales recognized as the Gnomoniaceae sensu stricto, Melanconidaceae sensu stricto, Schizoparme complex including the anamorph genera Coniella and Pilidiella, Cryphonectria-Endothia complex, Valsaceae sensu stricto, and Diaporthaceae sensu stricto. In addition, six teleomorphic and anamorphic taxa fell within the Diaporthales but were not allied with any of the six lineages.

• canker fungi
• Cryphonectria
• Diaporthe
• Discula
• phylogeny
• Valsa

The authors express sincere appreciation to Margaret Barr Bigelow, Sidney, British Columbia, for providing fresh specimens of diaporthalean fungi from which cultures were isolated as well as general expertise and advice on working with the Diaporthales. In addition we thank Sabine Huhndorf and Fernando Fernandez, Field Museum, Chicago, for sending the sequence and culture of Schizoparme botrytidis obtained while working under NSF-PEET grant #DEB-9521926. The following persons also sent isolates: Gerald Bills, Merck Research, Plagiostoma conradii; Scott Redlin, Animal and Plant Health Inspection Service, Apiognomnia errabunda and Cryptodiaporthe corni; and Jack Rogers, Washington State University, Pullman, Wuestneia molokaiensis. Finally, the skilled technical expertise of Douglas Linn, John McKemy, Brenda Paul, Frank Washington and Janelle Wood is acknowledged for handling the cultures and sequencing the newly obtained fungi.