Genetic mapping of pathogenicity and aggressiveness of Gibberella zeae (Fusarium graminearum) towards wheat

Publikations-Art

Zeitschriftenbeitrag

Autoren

Cumagun, C.J.R., R.L. Bowden, J.E. Jurgenson, J.F. Leslie, and T. Miedaner

Erscheinungsjahr

2004

Veröffentlicht in

Phytopathology

Band/Volume

94/

Seite (von - bis)

520-526

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 by simple interval analysis. 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. The two QTLs, however, were likely part of the same QTL by composite interval analysis. 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.