Association of allelic variation in two NPR1-like genes with Fusarium head blight resistance in wheat

Fusarium head blight (FHB) is a destructive disease of wheat and barley. In wheat it is mainly caused by the fungal pathogens Fusarium graminearum and Fusarium culmorum. We report the identification and evaluation of candidate genes for quantitative FHB resistance. These genes showed altered expression levels in the moderately resistant winter wheat genotypes Capo and SVP72017 after inoculation with F. graminearum. Amongst others, a NPR1-like gene was identified. Sequence analysis of this gene fragment revealed a high level of variation between the parents of a doubled haploid population. Single nucleotide polymorphism and polymerase chain reaction markers were developed and two homoeologous genes were mapped on the long arms of chromosomes 2A and 2D, respectively. Markers for both genes had significant effects on FHB resistance in a diverse collection of 178 European winter wheat cultivars evaluated in multi-environmental field trials after spray inoculation with F. culmorum. These results revealed that allelic variation in two homoeologous NPR1-like genes is associated with FHB resistance in European winter wheat. Markers for these genes might therefore be used for marker-assisted breeding programs.