ARS | Publication request: A novel species within the Fusarium graminearum complex from Ethiopia detected by a multilocus genotyping assay and molecular phylogenetics

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 2, 2008
Publication Date: September 2, 2008
Citation: O Donnell, K., Ward, T.J., Aberra, D., Aoki, T., Kistler, H.C., Bjornstad, A., Klemsdal, S.S. 2008. A novel species within the Fusarium graminearum complex from Ethiopia detected by a multilocus genotyping assay and molecular phylogenetics. Meeting Abstract.

Technical Abstract: Twenty isolates resembling members of the Fusarium graminearum species complex (Fg complex; O’Donnell et al., Fungal Genet. Biol. 41:600-623, 2004) were isolated from ground wheat samples collected in two different geographic areas in Ethiopia. Results of a multilocus genotyping (MLGT) assay (Ward et al., Fungal Genet. Biol. 2007, in press) suggested that these isolates might represent a new species within the Fg complex. To further assess species identity, phylogenetic analyses of multilocus DNA sequence data (13 genes; 16.3 kb/strain) resolved the Ethiopian isolates as a novel, strongly supported monophyletic sister group to F. acaciae-mearnsii within the Fg complex. These isolates also appear to be novel in that MLGT probes targeting Tri3 or Tri12 near the ends of the trichothecene (TRI) gene cluster suggested that the TRI cluster reflects recombination between isolates with a 15-acetyldeoxynivalenol (15ADON) and nivalenol (NIV) chemotype. Sequence analysis of either end of the TRI cluster identified 15ADON and NIV recombination blocks, demonstrating inter-chemotype recombination within the TRI cluster for the first time. Results of pathogenicity experiments and trichothecene analyses show that this novel Fg complex species can cause Fusarium head blight on wheat and elaborate 15ADON in planta.