The effect of three spray inoculation protocols on Fusarium head blight infection of wheat and in planta competition between 3-ADON & 15-ADON chemotypes of Fusarium graminearum

Abstract

Breeding for Fusarium head blight (FHB) resistance in wheat requires accurate and precise phenotyping. Additionally, breeding for FHB resistance requires an understanding of the pathogen population to which the host will be subjected. It is important to examine aspects of the competition between F. graminearum isolates that produce 3-acetyldeoxynivalenol (3-ADON) or 15- acetyldeoxynivalenol (15-ADON), including how infection by various isolates will affect the expression of resistance in wheat. The first objective of this study was to compare ranking of FHB reactions of ten wheat genotypes using three different macroconidial spray inoculation protocols and to determine if the protocols produce substantially equivalent results in terms of symptom development. The second objective was to examine the outcome of competition between 3-ADON and 15-ADON producing isolates of F. graminearum and to examine the effect inoculation with different isolate mixtures on FHB resistance in wheat genotypes 93FHB37 (resistant) and CDC Teal (susceptible).