PEET: Systematic Monography of the Gnomoniaceae (Ascomycetes)

The ascomycete order Diaporthales includes saprobic and plant pathogenic

fungi of which the most notorious is the chestnut blight fungus that altered the landscape of eastern North America. Forest and landscape diseases caused by members of the included family Gnomoniaceae include oak dieback, cherry leaf scorch, sycamore canker, ash anthracnose, dogwood anthracnose, butternut canker, and many others. These microfungi include many serious emerging and invasive plant pathogens, thus knowledge of their taxonomic affinities is crucial for rapid detection, control of the diseases they cause, determinination of their origin and close phylogenetic relatives, and prevention of future introductions. Although of considerable economic importance, fungi in the Diaporthales have not received modern monographic treatment nor have their related asexual fungi been included in their limited literature. A monographic account of this understudied group is needed to provide the taxonomic framework for understanding the evolution of invasive asexual fungi such as the causes of dogwood anthracnose and butternut canker.

The objective of this Partnership for Enhancing Expertise in Taxonomy (PEET) project is to monograph the ten major genera and related fungi of the ascomycete family Gnomoniaceae, order Diaporthales, including their derived asexual species using a combination of morphological and molecular approaches. The three groups of genera of the Gnomoniaceae will be studied as separate but interrelated projects. Several hundred living cultures and reference specimens are available for each group with additional material to be acquired through collecting and collaborating with scientists throughout the world. The research approach involves examination of macroscopic and microscopic characters using high quality light and scanning electron microscopy. A digital image analysis system will be used for measuring, recording, and analyzing microscopic characters as well as for capturing diagnostic images of spore-related structures. Morphological data and molecular DNA sequence data (nuclear ribosomal DNA regions and other genomic markers) will be used to develop hypotheses about lineages within the

Gnomoniaceae. These hypotheses will be tested using DNA sequence analyses of additional genes, specifically RNA polymerase B subunits 1 and 2, translation elongation factor 1 alpha, mitochondrial ATP6 and mitochondrial ribosomal DNA genes individually and in combination. Monographic accounts of these fungi will be published in mycological journals and placed on the Internet along with interactive identification keys supported by descriptions and illustrations.