EVALUATION OF A REAL-TIME QUANTITATIVE PCR ASSAY FOR AN EFFECTIVE SCREENING OF GENOTYPES WITH FHB RESISTANCE AND LOW MYCOTOXIN ACCUMULATION IN WHEAT AND BARLEY

To estimate fungal biomass in grains infected withFusarium graminearumcausing Fusarium Head Blight (FHB), a real-time PCR assay was applied for the quantification of the pathogen DNA based on the copy number of trichothecene synthesis gene (Tri5) sequence. Using 64 lines of wheat and barley in a field, we found significant correlations among the disease severity, deoxynivalenol (DON) accumulation and the pathogen DNA amount in the grains from each inoculated spike. The strong relationships were maintained in the susceptible population showing high DON accumulation but not the resistance population with low DON accumulation. These results indicate that the PCR assay could be useful for discarding the germplasm verysusceptible to FHB disease.