Submitted to: Mycological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 1995
Publication Date: N/A
Technical Abstract: Phylogenetic relationships among 100+ isolates within Section Liseola of Fusarium ["F. moniliforme-complex"] were investigated by comparing sequences from four genes. Congruence between the mitochondrial small rDNA and beta-tubulin gene trees indicate that these represent true species trees. Phylogenetic signal within the nuclear large 28S rDNA is poor. Surprisingly, the internal transcribed spacer gene tree is incongruent with the true species tree because the common ancestor of this species complex was polymorphic at this locus. Based on phylogenetic evidence, Section Liseola is paraphyletic with the exclusion of certain chlamydospore-forming species. Also other Sections are artificial and should be abandoned. We recommend the adoption of a phylogenetic species concept since current morphological and biological species concepts fail to describe the phyletic diversity and sister group relationships within this important group of fungi. These studies will form the foundation of a phylogenetically-based revision of Fusarium and its teleomorphs.