ARS | Publication request: DETECTION OF DISTINCT SUBPOPULATIONS OF FUSARIUM GRAMINEARUM, LINEAGE 7

Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract
Publication Acceptance Date: December 15, 2003
Publication Date: December 15, 2003
Citation: Gale, L.R., Ward, T.J., Balmas, V., Kistler, H.C. 2003. Detection of distinct subpopulations of fusarium graminearum, lineage 7 [abstract]. National Fusarium Head Blight Forum Proceedings. p. 139.

Technical Abstract: A collection of Fusarium strains associated with cereal head blight from nine U.S. states, representing 86 fields in 53 counties, was characterized using ten single-copy RFLP probes, a telomeric probe and RFLP probes diagnostic for the phylogenetic species within the Fusarium graminearum complex. In addition, isolates were assigned to one of three profiles of trichothecene metabolites (chemotypes) using a PCR-based approach. All 708 isolates determined to belong to the F. graminearum species complex were confirmed to be members of F. graminearum, lineage 7. The telomeric probe was used for clone determination, leaving 587 isolates for subsequent data analyses. Most F. graminearum, lineage 7 isolates (94.6%) from the U.S. were of 15acetyl deoxynivalenol(15ADON) chemotype. The 3acetyl deoxynivalenol (3ADON) chemotype was found at 5% and was only identified in samples from North Dakota and Minnesota. The nivalenol chemotype was infrequent at 0.4%. Gene flow analysis demonstrates that the 15ADON population in the U.S. is genetically isolated from the 3ADON population (Nm = 0.5). In comparison, a collection of 19 isolates of F. graminearum, lineage 7 from Italy was genetically similar to the 3ADON population from the U.S. (Nm > 2), though the Italian collection consisted of all three chemotypes. These results would indicate that F. graminearum, lineage 7 consists of at least two distinct subpopulations.