Submitted to: Sydowia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 21, 1996
Publication Date: N/A
Interpretive Summary: Species of Fusarium cause a wide range of plant diseases, mycotoxicoses, and fungal infection of humans and other animals. Identification of unknown isolates is problematical and subjective, given the paucity and plasticity of morphological traits. A DNA sequence database is being constructed in order to design molecular tools for the rapid and accurate identification of all unknown isolates of this agronomically important genus. The molecular database is also being used to develop a natural system of classification which will provide a theoretical framework for investigating the multifaceted biology of Fusarium in a genealogical context. A phylogenetic system is essential in order to provide a reference system that permits accurate communication of taxon names, access to the literature, and a context for making predictions about the biological activities of these fungi.
Technical Abstract: A DNA sequence database is being developed for all species of Fusarium which will be used to construct a phylogenetically-based classification and to develop molecular tools for the rapid and accurate identification of unknown isolates. Multiple genetic loci are being sequenced to generate independent phylogenetic hypotheses to identify monophyletic taxa and resolve sister group relationships. Deficiencies in morphological and biological species concepts are illustrated by selected examples within two paraphyletic sections, Liseola and Martiella. Both groups contain polytypic species (e.g., F. verticillioides, synonym = F. moniliforme and Nectria haematococca/F. solani) for which a phylogenetic species concept is being developed. Phylogenetic reconstruction from the molecular data indicates that Fusarium, Nectria and subgenus Dialonectria are paraphyletic as currently defined. A proposal for elimination of the paraphyly of these taxa is presented.