Submitted to: Eukaryotic Cell
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/26/2001
Publication Date: N/A
Citation: Interpretive Summary: The disease Fusarium head blight or scab has cost agriculture losses to the wheat and barley crops. The disease causes losses in yield, reduces wheat baking quality and contaminates harvested grain with mycotoxins such as deoxynivalenol which are a human and animal health threat. A genetic linkage map has been constructed for the fungus that causes Fusarium head blight (scab) of wheat and barley in the United States and worldwide. The map was made by doing a classical genetic cross of two diverse strains of this fungus, one from a Kansas wheat field and the other from Japan. Ninety-nine selected recombinant progeny were then analyzed using a technique called Amplified Fragment Length Polymorphisms and 502 unique locations were identified comprising nine linkage groups. It was found that two of these locations contained genes that controlled the trichothecene toxin amount and type. These toxins have previously been shown to be important for the fungus to cause disease. This map will be useful in development of strategies to prevent this disease in crops and protect the safety of the food supply by elimination of the toxins.
Technical Abstract: We constructed a genetic linkage map of Gibberella zeae (Fusarium graminearum) by crossing complementary nitrate non-utilizing (nit) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate utilizing (recombinant) progeny and analyzed them for Amplified Fragment Length Polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1051 polymorphic markers that mapped to 502 unique loci on nine linkage groups. The total map length is approximately 1300 centiMorgans with an average interval of 2.5 map units between loci. Three of the resulting nine linkage groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two linkage groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol versus nivalenol) map on linkage groups IV and I, respectively. This linkage map will be useful in population genetic studies, in map-based cloning, for QTL analysis, for ordering genomic libraries, and for genomic comparisons of related species.