ARS | Publication request: GENETIC VARIATION AMONG ISOLATES OF ASPERGILLUS TAMARII, ASPERGILLUS CAELATUS AND AFLATOXIN PRODUCING A. TAMARII-LIKE ISOLATES

Submitted to: Mycological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: August 3, 2000
Publication Date: N/A

Technical Abstract: Aflatoxin producing isolates of A. tamarii were reported for the first time by Goto et al. Because there are physiological and morphological differences between aflatoxigenic and non-aflatoxigenic isolates, relationships were phylogenetically analyzed from beta-tubulin, calmodulin, norsolorinic acid reductase, ITS, and partial 28S rDNA gene sequences. Inferred amino acid sequences in the protein coding portions of the beta-tubulin, calmodulin, and norsolorinic acid reductase genes were invariant, but introns from these genes were highly variable. Parsimony trees based on each protein coding gene were congruent and show that Aspergillus caelatus and A. tamarii, as well as aflatoxin producing isolates of A. tamarii, form genetically distinct groups. ITS and 28S rDNA resolved only some of the branches resolved by the protein genes. The PHT showed that the protein gene sequences could be combined, and the combined data tree shows very high bootstrap support for each branch. Although the morphological differences between the aflatoxigenic and non- aflatoxigenic A. tamarii isolates are small, the genetic divergence is similar to that between A. flavus and A. parasiticus, and a new species name has been proposed for the aflatoxigenic A. tamarii isolates.