Submitted to: Mycological International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 31, 2006
Publication Date: September 26, 2006
Citation: Desjardins, A.E., Busman, M., Maragos, C.M., Stessman, R.J., Proctor, R. 2006. The role of fusarium biodiversity in plant pathogenicity and biological control [abstract]. Mycological International Conference. p. 42. Technical Abstract: The Fusarium disease complexes of maize, wheat, and other cereal grains are biologically highly diverse. This biodiversity is believed to have a major impact on the types and levels of mycotoxins in food grains. The first dimension of complexity is at the Fusarium species level. Identification and quantification of these species can be accomplished using morphological traits, molecular markers, and other genetic approaches now available or under development. The next dimension of complexity is at the species population level where molecular markers have identified various populations, some of which have been designated as phylogenetic lineages or cryptic species. The taxonomy of Fusarium species in cereal disease complexes is well-advanced for North America and Europe, but remains largely unexplored for developing countries of Africa, Asia, and South America. Further information is needed worldwide on how genetic diversity is linked to agriculturally important traits. We are investigating population genetics, plant pathogenicity, and mycotoxigenicity of the Fusarium disease complexes of maize and wheat in the United States and Nepal. In maize field tests, two cryptic species of F. subglutinans caused high levels of ear rot and contamination of grain with moniliformin (100-1500 ug/g). In wheat greenhouse tests, three genetically distinct populations of F. graminearum from Nepal differed in virulence on wheat, and in production of the trichothecenes nivalenol and deoxynivalenol. Also in wheat greenhouse tests, strains of F. proliferatum from Nepal and the United States caused black point and B-fumonisin contamination (2-50 ug/g). Further studies are needed to determine whether production of mycotoxins in cereal grains is affected by interactions among species of the Fusarium disease complexes, and whether Fusarium biodiversity can be exploited to control mycotoxins in grains.