Evaluation of select spring barley accessions for resistance to Fusarium head blight and deoxynivalenol accumulation

Fusarium head blight (FHB), a devastating disease of barley caused primarily by the fungus Fusarium graminearum, causes significant yield losses and grain contamination with mycotoxins. Enhancing resistance to FHB and the resultant accumulation of mycotoxins, such as deoxynivalenol (DON), is an effective and economical method of reducing losses caused by this disease. A diverse panel of 234 barley accessions from worldwide origins was assembled and evaluated in head-to-head comparisons over multi-year and multi-environment field trials to identify those that perform consistently well with respect to FHB resistance and DON accumulation under Upper Midwest conditions. In addition to these two traits, row type, heading date, plant height, kernel density, and node density assessments were also recorded to investigate the relationship between these agro-morphological traits and both DON concentration and FHB severity. Accessions were genotyped with a barley 50k single nucleotide polymorphism microarray in order to assess their population structure and genetic relationships and also investigate patterns of disease resistance. Several accessions originating from diverse backgrounds were identified as having moderately high resistance to FHB and/or DON accumulation. However, most accessions with low disease severity and mycotoxin accumulation also had undesirable agro-morphological traits, a challenge in breeding for FHB resistance in barley. The data generated in this study will be a valuable resource for resistance breeding and genetic mapping of resistance to FHB and DON accumulation.