Scott Fisk

The Genetics of Winterhardiness in Barley: Perspectives from Genome-Wide Association Mapping

Winterhardiness is a complex trait that involves low temperature tolerance (LTT), vernalization sensitivity, and photoperiod sensitivity. Quantitative trait loci (QTL) for these traits were first identified using biparental mapping populations; candidate genes for all loci have since been identified and characterized. In this research we used a set of 148 accessions consisting of advanced breeding lines from the Oregon barley (Hordeum vulgare L. subsp vulgare) breeding program and selected cultivars that were extensively phenotyped and genotyped with single nucleotide polymorphisms. Using these data for genome‐wide association mapping we detected the same QTL and genes that have been systematically characterized using biparental populations over nearly two decades of intensive research. In this sample of germplasm, maximum LTT can be achieved with facultative growth habit, which can be predicted using a three‐locus haplotype involving FR‐H1, FR‐H2, and VRN‐H2. The FR‐H1 and FR‐H2 LTT QTL explained 25% of the phenotypic variation, offering the prospect that additional gains from selection can be achieved once favorable alleles are fixed at these loci.

Effects of Barley (Hordeum Vulgare L.) Variety and Growing Environment on Beer Flavor

This research tested the hypothesis that barley genotype can affect beer flavor and assessed the relative contributions of genotype and location to beer sensory descriptors. Golden Promise, Full Pint, 34 of their doubled haploid progeny, and CDC Copeland were grown at three locations in Oregon, U.S.A. Grain from these trials was micromalted and the resulting malts used for nano-brewing. Sensory evaluations were conducted on the nano-brews. Barley genotype had significant effects on many sensory descriptors. The most significant sensory descriptors—when comparing barley genotypes—were cereal, color, floral, fruity, grassy, honey, malty, toasted, toffee, and sweet. Golden Promise was significantly higher in fruity, floral, and grassy flavors, whereas Full Pint was significantly higher in malty, toffee, and toasted flavors. CDC Copeland was closest to neutral for most flavor traits. There were notable differences for some descriptors between locations. New combinations of parental flavor attributes were observed in the progeny. Multitrait analysis revealed regions of the barley genome with significant effects on malting quality and flavor traits. These findings are, of course, applicable only to the barley germplasm tested, the environment sampled, and the protocols used for micromalting and brewing. The necessary larger-scale experiments involving optimized malts and larger volumes of beer are in process.

Malt modification and its effects on the contributions of barley genotype to beer flavor

Based on prior research that showed significant genetic differences between barley genotypes for beer sensory descriptors, the effects of degree of malt modification on these descriptors were assessed in two experiments. The first experiment involved sensory assessment of nano-beers made from micromalts of Golden Promise, Full Pint, 34 doubled haploid progeny, and the check CDC Copeland. Average degree of modification was assessed by sampling grain from each of the 37 genotypes stored for three postharvest intervals prior to malting and brewing. The second experiment involved sensory assessment of pilot beers made from intentionally under-, properly, and overmodified pilot malts of two barley varieties: Full Pint and CDC Copeland. In both experiments, genotypes were the principal sources of significant variation in sensory descriptors. Degree of modification and genotype × modification interactions were also significant for some descriptors. Based on the results of this study, the genetic characterization of and selection for barley contributions to beer flavor are warranted, even with undermodified malts. The contribution of barley variety to beer flavor will likely be modest compared with the flavors developed during the malting process and the flavors contributed by hops and yeast. However, in certain beer styles, the contributions of barley genotype may be worth the attention of maltsters, brewers, and consumers.

3 – Food Barley Quality Improvement and Germplasm Utilization

Barley is one of the oldest known domesticated crops. Originally cultivated for human consumption, other end-uses have gained importance over the millennia. Today, barley is the fourth most important cereal crop in the world and is mainly used as animal feed or malted for brewing and distilling. Wheat and rice have largely replaced barley as a staple food. But there are still many areas of the world where barley remains a staple crop and has important spiritual, nutritional, and cultural significance. In this chapter, we summarize the history of barley foods, discuss their resurgence, and use the Oregon State University (OSU) food barley breeding initiative as a case study in germplasm development and variety release. Civilization faces the tremendous challenges of climate change and ensuring a stable, nutritious, and diverse food supply. Food barley can be part of the solution. One approach to accelerating the acceptance of food barley and to ensuring its broader utilization is to focus on its unique attributes. We argue that naked (hull-less) food barley should be viewed as an entirely new cereal crop with agronomic, nutritional, and end-use advantages. It is early maturing and input-use-efficient. It has unique dietary fiber and nutritional characteristics. And finally, it offers a palette of new flavors and qualities for a range of foods.