Ames, Nicholas2017-11-272017-11-272014-10https://hdl.handle.net/11299/191204University of Minnesota M.S. thesis. October 2014. Major: Applied Plant Sciences. Advisor: Gary Muehlbauer. 1 computer file (PDF); viii, 113 pages.Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh) is a worldwide disease with severe impact on yield in barley (Hordeum vulgare). This study describes the characterization of a collection of 316 wild barley accessions, known as the Wild Barley Diversity Collection (WBDC), for resistance to powdery mildew. The WBDC was phenotyped for reaction to 40 different Bgh isolates at the seedling stage and then genotyped with three different marker sets: 3,072 Single Nucleotide Polymorphisms, 600 Diverse Array Technology (DaRT) markers, and 8,616 Diverse Array Technology-Sequencing (DArT-Seq) markers. Fifty-two accessions exhibited resistance to 90% (20 of 40) of the Bgh isolates. Significant marker-trait associations were found for all marker types at nineteen different loci across the barley genome encompassing all chromosomes except 1H in a GWAS analysis. These marker-trait associations will be useful for incorporating powdery mildew resistance into barley breeding programs.enThesis or Dissertation