Disease resistance is an important component of an integrated strategy to manage Fusarium head blight (FHB) disease and to prevent the accumulation of mycotoxins in the grain. Extensive evaluations of barley germplasm for FHB resistance have been conducted over the past two decades but resulted in the identification of only a limited number of accessions with partial resistance. The wild progenitor of barley (Hordeum vulgare ssp. spontaneum) is a rich source of disease resistance for breeding. A set of wild barley introgression lines (S42IL) was developed by crossing the wild barley accession ISR42-8 from Israel with the German malting cultivar Scarlett. This population was subsequently genotyped with the 3K SNP chip to characterize the introgressions from ISR42-8 in the Scarlett background. Evaluations of this population (N=64) over three years at two sites (Crookston and St. Paul) in Minnesota with multiple replications (2-3) revealed a wide range of variation with respect to FHB severity (0.45% to 50.67% with an overall mean of 11.6%) and DON accumulation (0.47 to 42.3 ppm with an overall mean of 9.3 ppm). For Scarlett, the mean and range of FHB severity was 8.6% and 2.8%-14.9% and for DON accumulation 8.5 ppm and 1.3-15.8 ppm, respectively. No data were obtained for ISR42-8 because it did not produce robust plants in the field. A linkage map for the S42IL population was constructed with the 3K data using IciMapping software. The analysis revealed 12 QTLs for FHB severity in at least one environment: ten on chromosome 2H, one on 4H, and one on 5H. All but two of these FHB QTL co-located with heading date, suggesting a pleiotropic effect.  Fifteen QTLs for DON accumulation were found in at least one environment: one each on chromosomes 2H and 5H, two on 4H, three on 6H and seven on 7H. One DON QTL on 7H was observed over multiple environments. None of the QTLs identified for DON co-located with QTLs for FHB or any agro-morphological trait. Scarlett contributed the favorable allele for lower FHB and DON in six of 12 and 12 of the 15 identified QTLs, respectively.  ISR42-8 contributed four favorable alleles for low FHB on 2H and three favorable alleles for low DON on 7H. Introgression lines S42IL-124, S42IL-126, S42IL-176, and S42IL-102 exhibited the lowest DON levels across the population and may be useful for breeding programs for malting barley.

Acknowledgement and Disclaimer

This research is based in part upon work supported by the U.S. Department of Agriculture, under 59-0206-2-147, “Genetic Enhancement of Fusarium Head Blight (FHB) Resistance in Barley.” This is a cooperative project with the U.S. Wheat & Barley Scab Initiative.