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United States Department of Agriculture

Agricultural Research Service

Related Topics


Location: Cereal Crops Research

2012 Annual Report

1a. Objectives (from AD-416):
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.

1b. Approach (from AD-416):
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.

3. Progress Report:
Fundamental basis of malting quality research. Data from malting quality analysis and activities of three classes of proteolytic enzymes for a genetically defined population of barley were provided to our collaborating barley breeding colleagues. This population (recombinant chromosomal substitution lines) consists of 300 backcrossed lines each containing discrete chromosomal segments from a wild barley (Hordeum spontaneum) in a background of a high-quality malting barley (c.v. Harrington). Analysis of malting quality data, proteinase activity, in the context of the genetic composition of the lines, will allow association of the variations in malting quality and proteinase activity with either wild or malting barley, as well as quantitative trait loci (QTL) identified in the lines. Preliminary analysis of the data shows clear QTL associated with proteinase activities (first observation of proteinase QTL). Detailed analysis and manuscript preparation with collaborators are in progress. Similarly, analysis of the proteinase activities and malting quality of 2009 crop year breeders submissions and manuscript preparation from samples included in the Barley Coordinated Agricultural Project are also in progress. Novel malting quality measurement methodology. We completed and published a study examining methods for use of a microplate reader to analyze wort free amino nitrogen (FAN) concentrations in a reduced-volume format amenable to the small volume worts developed recently. Interestingly, we found that simply adjusting volumes of the standard FAN methodology did not result in reliable, comparable results at the micro scale. However, after evaluation of a number of experimental parameters and chemistry, we identified a suitable modification that allowed reliable estimation of wort FAN content at the reduced volumes. Malting Quality Analysis (QA) support. Our QA program malted and analyzed over 5000 barley samples for United States public sector barley breeding programs in routine operation. In addition, we malted and analyzed approximately 500 nursery and special project samples for stakeholders, providing accurate results and analysis in a timely fashion meeting needed or requested reporting dates.

4. Accomplishments
1. Protein mobilization and malting quality. Analysis of proteinase activity and malting quality with reference to genetic composition of malting barley is needed to illuminate poorly-understood mechanisms of protein mobilization during malting and identify new ways to select improved malting varieties. We have leveraged the genetic resources available in malting barley breeding and research programs. In order to identify associations between malting quality and proteinase activity measurements, identifying genetic loci for proteinase genes associated with malting quality. This genetic dissection of protein mobilization will identify specific proteinases involved in malting quality that have not been identified by classic proteinase biochemistry. Identification of specific proteinases involved in production of desired malting quality attributes will allow a more targeted, more efficient approach to development of improved malting quality varieties.

2. Development of novel assays for malting quality. Classic “approved” malting quality assay methods are not well suited to current needs for germplasm characterization for malting barley improvement. We developed an improved method for determination of the amino acid content of wort (hot water extract of barley malt, the initial step in brewing beer) that is efficient, accurate, and reproducible. The method is very well suited to the small-volume/high-throughput format needed for germplasm characterization essential for development of novel malting barley varieties meeting current and future needs of the malting and brewing industries. This and other recently developed small volume malting and malting quality methods enable a shift from the old Quality Analysis methods designed for malthouse and brewery use (few samples available in large quantity) to a new paradigm of large numbers of small-quantity samples that meets the needs of barley breeding programs. This will aid in development of new malting barley varieties.

Review Publications
Schmitt, M., Budde, A.D. 2011. Malting extremely small quantities of barley. Journal of American Society of Brewing Chemists. 69(4):191-199.

Schmitt, M., Budde, A.D. 2012. Wort free amino nitrogen analysis adapted to a microplate format. Journal of American Society of Brewing Chemists. 70(2):95-102.

Last Modified: 06/22/2017
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