Developing a DNA fingerprint for midwest six-rowed malting barley

The requirements for brewing beer from barley ( Hordeum vulgare L.) malt are specific and unique for each brewer. Anheuser-Busch InBev and Miller Coors Brewing Company (MillerCoors) are two major brewers in the United States that target different malt quality profiles for six-rowed barley malt. Two closely related cultivars developed by the University of Minnesota, Robust and Stander, differ greatly in agronomic and malt quality performance. Robust malt fits the requirements of MillerCoors and Stander malt has many of the parameters desired by Anheuser-Busch InBev. The close relationship between these two cultivars increases the chance of recognizing chromosome regions with the genes controlling malt quality traits. A total of 53 doubled-haploid (DH) lines (original population) and the parents from the Robust x Stander cross were grown at eleven locations in North Dakota and one location in Idaho the past six years. An additional 138 Robust x Stander DH lines were generated in 2009 and were evaluated alongside the original DH population in the summer of 2011 at two North Dakota locations. Agronomic data were collected at all locations and cleaned grain samples of the original population from six of the locations were micro-malted at NDSU. Three linkage maps were developed using the original and 191 DH line (entire) populations. The first linkage map was constructed using the original DH population, along with a total of 102 SNP, SSR, and DArT markers. The second and third linkage maps were developed using only 67 SNP markers, with the original and entire Robust x Stander DH population, respectively. The first map was used to identify QTL controlling malt quality and wort carbohydrate traits on chromosomes 4H, 5H, and 6H. The SNP map constructed using the original DH population was used to identify QTL controlling agronomic traits on chromosome 6H. The third map was used to identify QTL controlling agronomic traits on chromosomes 4H and 6H. The ultimate goal for this research in years to come is to develop a genetic haplotype that helps distinguish six-rowed barley lines suitable for MillerCoors and Anheuser-Busch InBev.