Cereal Disease Laboratory : How many species of the Fusarium head blight fungus are there?

Eleven phylogenetic species are now recognized within the Fusarium graminearum species complex (Starkey, et al., 2007. Fungal Genetics and Biology doi:10.1016/j.fgb.2007.03.001). Species are often limited to particular regions of the world, although the origin of many of these species, including Fusarium graminearum sensu stricto remains uncertain.

Many of these species contain strains capable of causing FHB on wheat.
Only one of these species is currently known to exist in production wheat and barley fields in the U.S.

For more information see:

O’Donnell, K., H.C. Kistler, B.K. Tacke, and H.H. Casper. 2000. Gene genealogies reveal global phylogeographic structure and reproductive isolation among lineages of Fusarium graminearum, the fungus causing wheat scab. Proc. Natl. Acad. Sci. USA 97:7905-7910.

Ward, T.J., J.P. Bielawski, H.C. Kistler, E. Sullivan and K. O'Donnell. 2002. Ancestral polymorphism and adaptive evolution in the tricothecene mycotoxin gene cluster of phytopathogenic Fusarium. Proc. Natl. Acad. Sci. USA 99:9278-9283.

O'Donnell, K., T. J. Ward, D. M. Geiser, H. C. Kistler, and T. Aoki. 2004. Genealogical concordance between the mating type locus and seven other nuclear genes supports formal recognition of nine phylogenetically distinct species within the Fusarium graminearum clade. Fungal Genet.Biol. 41:600-623.

Starkey, D.E., Ward, T.J., Aoki, T., Gale, L.R., Kistler, H.C., Geiser, D.M., Suga, H., Toth, B.,
Varga, J. and O'Donnell, K. 2007. Global molecular surveillance reveals novel Fusarium head blight species and trichothecene toxin diversity. Fungal Genetics and Biology: doi:10.1016/j.fgb.2007.03.001.