Hawkins, John2022-09-132022-09-132022-07https://hdl.handle.net/11299/241560University of Minnesota M.S. thesis. 2022. Major: Applied Plant Sciences. Advisor: Kevin Smith. 1 computer file (PDF); 102 pages.Hull-less or naked barley (Hordeum vulgare L.) is a grain of growing importance in food, feed, and malting applications. Fusarium Head Blight (FHB), a disease caused by fungi in the genus Fusarium, causes significant damage to barley grain through accumulation of mycotoxins and undesirable fungal proteins and reduction of grain mass and malting quality. The most important Fusarium mycotoxin in North America is deoxynivalenol (DON). Naked barley accumulates significant amounts of DON in hull tissue, which is discarded at threshing, providing a mechanism for limiting FHB discounts due to mycotoxin contamination. For this research, genome wide association studies were performed using the Naked Barley Diversity Panel genotyped with an array of 50,000 single nucleotide polymorphisms (SNPs) and phenotyped for traits associated with DON distribution in the barley spike. Three notable quantitative trait loci (QTLs) for disease related traits were discovered. A QTL on the short arm of chromosome 3H, linked to a hydroxyproline rich glycoprotein gene was associated with reduced FHB severity. Another QTL on the long arm of 3H, linked to sdw1, was associated with shorter plants, greater FHB severity under grain spawn inoculation, and earlier heading. A third QTL on the short arm of 2H, linked to PPD-H1, was associated with taller plants, later heading, and a greater proportion of the total DON being localized in the hull. Overall, there appears to be potential for the improvement of FHB resistance and DON mitigation in naked barley.enBarleyDeoxynivalenolFusarium Head BlightGWASNaked BarleyScabThesis or Dissertation