Submitted to: Mycological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: July 31, 2003
Publication Date: N/A
Technical Abstract: Peterson (2000) analyzed relationships in the "A. ochraceus group" (Raper & Fennell, 1965) using a short segment of large subunit rDNA. On the basis of that analysis, several species were removed from the section and some potential synonymies were detected. To determine if these closely related isolates are separate phylogenetic species, additional sequences were obtained from the ITS region, mitochondrial small subunit rDNA, the calmodulin gene, and translation elongation factor 1 alpha. Included in one lsu rDNA clade were isolates of A. ostianus, A. petrakii, A. melleus, and A. ochraceus. In multi-locus analysis, A. ochraceus and A. petrakii isolates are indistinguishable, and thus synonymy is supported. The distinctions of A. ochraceus, A. ostianus and A. melleus are substantiated by the congruence of trees from multiple loci. One isolate of "A. petraki" was not part of the three supported species and probably represents an undescribed species. A. insulicola and A. ochraceopetaliformis, with identical lsu rDNA sequences, show single base differences at each of the additional loci, and these taxa are retained tentatively as distinct species; additional isolates of these are needed to clarify their relationship. A. bridgeri and A. sclerotiorum were identical in lsu rDNA but differ at other loci suggesting that these are sister species. Two isolates phenotypically identified as A. bridgeri are genetically distinct and may represent two additional undescribed species in Aspergillus section Circumdati.