Author
CUMAGUN, CHRISTIAN J. - UNIV. HOHENHEIM - GERMANY | |
Bowden, Robert | |
JURGENSON, JAMES - UNIV. OF NORTHERN IOWA | |
LESLIE, JOHN - KSU - PLANT PATHOLOGY | |
MIEDANER, THOMAS - UNOV. HOHENHEIM - GERMANY |
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/27/2004 Publication Date: 5/15/2004 Citation: Cumagun, C.R., Bowden, R.L., Jurgenson, J.E., Leslie, J.F., Miedaner, T. 2004. Genetic mapping of pathogenicity and aggressiveness of gibberella zeae (fusarium graminearum) toward wheat. Phytopathology. 94:520-526. Interpretive Summary: Gibberella zeae is the major fungal pathogen of Fusarium head blight of wheat and produces several mycotoxins harmful to humans and domesticated animals. We identified chromosomal regions associated with pathogenicity and aggressiveness on a genetic map of G. zeae in a cross between a lineage 6 nivalenol producer from Japan and a lineage 7 deoxynivalenol producer from Kansas. We mapped one major gene that controls pathogenicity in the region that controls toxin amount. We mapped one or two minor genes that control aggressiveness in the region that controls toxin type (nivalenol or deoxynivalenol). Progeny that produced deoxynivalenol were, on average, about twice as aggressive as were those producing nivalenol. The rather simple inheritance of both traits in this interlineage cross suggests that relatively few loci for pathogenicity or aggressiveness differ between lineage 6 and 7. Technical Abstract: Gibberella zeae is the major fungal pathogen of Fusarium head blight of wheat and produces several mycotoxins harmful to humans and domesticated animals. We identified loci associated with pathogenicity and aggressiveness on an Amplified Fragment Length Polymorphism (AFLP)-based genetic map of G. zeae in a cross between a lineage 6 nivalenol producer from Japan and a lineage 7 deoxynivalenol producer from Kansas. Ninety-nine progeny and the parents were tested in the greenhouse in two years. Progeny segregated qualitatively 61:38 for pathogenicity:nonpathogenicity. The trait maps to linkage group IV adjacent to loci that affect colony pigmentation, perithecium production, and trichothecene toxin amount. Among the 61 pathogenic progeny, the amount of disease induced (aggressiveness) varied quantitatively. Two reproducible quantitative trait loci (QTL) for aggressiveness were detected on linkage group I. A QTL linked to the TRI5 locus (trichodiene synthase in the trichothecene pathway gene cluster) explained 51% of the variation observed and a second QTL some 50 cM away, 29% of the phenotypic variation. TRI5 is tightly linked to the locus controlling trichothecene toxin type. Progeny that produced deoxynivalenol were, on average, about twice as aggressive as were those producing nivalenol. No transgressive segregation for aggressiveness was detected. The rather simple inheritance of both traits in this interlineage cross suggests that relatively few loci for pathogenicity or aggressiveness differ between lineage 6 and 7. |