Patterns of trichothecene production, genetic variability, and virulence to wheat of Fusarium graminearum from smallholder farms in Nepal.
, Jarosz AM
, Plattner RD
, Alexander NJ
, Brown DW
, Jurgenson JE
Mycotoxin Research, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, Peoria, IL 61604, USA. email@example.com
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Fusarium graminearum causes wheat head blight and contaminates grain with the trichothecenes 4-deoxynivalenol and nivalenol. Sequence analysis of trichothecene genes indicates that nivalenol production is the ancestral trait; however, deoxynivalenol producers occur worldwide and predominate in North and South America and in Europe. Analysis of a large field population (>500 strains) from Nepal identified three groups that were both genetically distinct and polymorphic for trichothecene production: SCAR1 comprising 95% deoxynivalenol producers, SCAR2 comprising 94% nivalenol producers, and SCAR3/5 comprising 34% deoxynivalenol producers/63% nivalenol producers. The ability to cause wheat head blight differed between SCAR groups and trichothecene chemotypes: deoxynivalenol producers were more virulent than nivalenol producers across all three SCAR groups and within the SCAR3/5 genetic background. These data support the hypothesis that production of deoxynivalenol rather than nivalenol confers a selective advantage to this important wheat pathogen.
PMID: 15453711 [PubMed - indexed for MEDLINE]