Location: Cereal Crops Research
2019 Annual Report
Objectives
Objective 1. Identify, develop, validate, and implement new measurements of malting quality, especially those relating to protein mobilization during germination, in barley germplasm in order to identify those genotypes showing enhanced malting quality attributes. Objective 2. Apply standard malting quality assessments to germplasm submitted by collaborating public sector barley breeding programs, researchers, and other stakeholder organizations in order to identify new (barley) varieties with suitable malting quality attributes.
Approach
Surveying populations that have been extensively genotyped and mapped for malting
quality will allow us to generate datasets that include process (proteinase
activity), phenotype (malting quality), and genotype (>3000 SNP loci) information. Examining a range of barley genetic resources will enable us to use that genetic diversity to identify fundamental processes underlying malting quality. We will use this information to identify new targets and develop additional mechanisms to screen for improved malting barley genotypes. The new screening mechanisms may involve biochemical measurements that we could implement in our malting quality analysis program. Alternatively, the new tests could utilize genetic tools that breeders could incorporate into their own germplasm characterization, simplifying and streamlining their malting quality selection process.
Progress Report
Malt Quality Analyses support. The ARS in Madison, Wisconsin met over 5400 requests for malting quality analytical data from public-sector barley germplasm enhancement programs and collaborating barley researchers. Barley testing was performed on over 110 samples to assist stakeholders in their selection of material for pilot scale malting and testing brewing trials to determine suitability of germplasm for release as an approved malting quality variety with the potential for value added payment. We also began to implement new malting equipment that will allow us to reduce sample size and eventually increase the rate and throughput of our services. The reduced-scale methodologies developed for generating malts and for conducting many standard tests have been adopted by additional barley research programs.
Phenotypic and Genotypic evaluation of Preharvest Sprouting (PHS)in 2 and 6 row barley. This was the second year of evaluating two and six row malting for propensity to preharvest sprout. Defined as precocious germination of seed prior to harvest, preharvest sprouting results in significant losses to growers of malting barley and therefore presents a tangible risk of reduced returns. Preharvest sprouting is most common in regions with excessive rain or humidity during seed ripening. We have extended our study from last year’s evaluation to also include a population of barley originating from a globally diverse set of locations and exhibits a variety of resistance levels to preharvest sprouting. Each of the lines were grown in replicated field trials at Montana State Ag station. The barley “heads” were harvested and challenged to preharvest sprout in artificial rain chambers. ARS scientists in Madison Wisconsin, in collaboration with scientists at Montana State University demonstrated variability in resistance levels within the germplasm interrogated, and therefore, the promise of developing genetic resources for combating the issue.
Study of Malting Regime. The malting regime, that is, the method in which barley is steeped, germinated and kilned to produce malt, can be adjusted to modulate a variety of key malt quality traits important to the brewing industry. The ARS malt quality lab uses a well-established malting regime that strictly adheres to the methods approved by the American Society of Brewing Chemists (ASBC). Since other malt quality labs do not necessarily follow these methods and may introduce additional nuances to their regime, it’s important to understand how these differences manifest themselves in the malt quality results. In this study, ARS scientists in Madison, Wisconsin, in collaboration with the Malt Quality lab at Montana State University, compared different malting regimes and assessed the quality of the resulting malt to better understand how the evaluative parameters are affected by the actual regime used. The results provided evidence that differences specific to the steeping regime used between the two labs can alter the results of the quality analysis.
Survey of RNA Binding Proteins in the Barley Genome. RNA binding proteins are a large family of proteins found in all plants. RNA binding proteins (RBPs) are key players of RNA metabolism that includes synthesis, processing, editing, modifying, transport, storage and stability of RNA and as a result can have profound effects on the expression of genes. ARS scientists in Madison, Wisconsin, scoured the current genomic sequence of barley for the presence of RNA binding proteins. The survey revealed the presence of over 363 RNA binding proteins in the current genome model. Further studies specific to malting of barley revealed over 38 RNA binding proteins that were expressed during various malting steps suggesting an important role for these proteins during the malting and germinative stages of barley development.
Accomplishments
Review Publications
Vinje, M.A., Walling, J.G., Henson, C.A., Duke, S.H. 2019. Comparative gene expression analysis of the beta-amylase and hordein gene families in the developing barley grain. Gene. 693:127-136.
Duke, S.H., Henson, C.A., Vinje, M.A., Walling, J.G., Bockelman, H.E. 2019. Comparisons of modern United States and Canadian malting barley cultivars with those from pre-Prohibition: V. Bmy1 intron III alleles and grain beta-amylase activity and thermostability. Journal of American Society of Brewing Chemists. 77(1):62-68. https://doi.org/10.1080/03610470.2018.1546110.
