**MetaBrew:**

**A comprehensive database of malting quality traits in brewing barley**

[S. Weise, U. Scholz, M.S. Röder, I.E. Matthies\*]{.smallcaps}

Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstr.
3, 06466 Gatersleben, Germany

\*Corresponding author, matthies@ipk-gatersleben.de

### Abstract

MetaBrew is a manually curated and comprehensive repository of high
quality analysis data concerning kernel, malting and brewing quality of
barley cultivars. This includes meta information about the genotypic and
phenotypic background (pedigree, row number, seasonal habit,
environment, experiment sources). Exploration and export of the
information is supported by a web application. MetaBrew is available at
http://metabrew.ipk-gatersleben.de.

**Key words:** barley -- malting quality -- phenotypic traits

### Introduction

Although barley is mainly used for feed, the production of malt for
products such as beer and whisky is of high economical importance (Fox
et al. 2003). Due to the complexity of traits involved in the malting
and brewing process, the selection of suitable cultivars and breeding
strains to improve the quality is difficult, time consuming and
expensive while most of these parameters show a high variation in their
performance. Therefore, it is beneficial to have a broad phenotypic data
basis in order to evaluate quality levels by statistical methods.

Here, we present a database to screen for phenotypic data interesting
for any breeding and malting programme. We are using this data stock to
perform association studies in order to select diagnostic markers in
candidate genes important for malting quality. Due to the requests of
breeders and researcher colleagues we would like to make this data
repository publicly available and offer possibilities for searching,
filtering and extracting data.

### Database description

For persistent storage of the MetaBrew data the relational database
management system Oracle is used, whereas the MetaBrew application is
based on the Oracle Application Express (APEX) technology. This
application is split into two parts. The first one is intended to
collect and to curate data and is restricted only for internal access.
The second part is a read-only web application thus allowing browsing,
searching and exporting of data.

#### Content

MetaBrew comprises phenotypic data of 96 malting and brewing parameters
obtained from 162 barley cultivars. The data collection comprises older
and modern European varieties from the past 20 years (1985--2005) grown
at different locations in Germany. Raw data was recorded either from the
statistical year books of the German Brewing Society or from official
trials by the German Seed Board. This data was hand-curated and
organised. Therefore, the data was recorded in MS-Excel templates and
imported using Java-based procedures. Consistency checks were performed
during the import. Links to the original experiments and information
such as the locations data has been collected at, soil conditions or
types of testing are available. Furthermore, additional background
information about pedigree, row number etc. was obtained either by
personal communication with barley breeders or from official information
from seed boards. MetaBrew contains single entries (one cultivar at one
location in one year) and average entries (one cultivar in one year at
several locations). Average values were labelled and, if available,
stored together with the number of single entries used to calculate the
average. To ensure a high data quality, all entries were cross-checked
manually. Controlled vocabulary (e.g. trait names) was used to ensure
consistency and to allow single data comparisons from different sources.
Up to now, approximately 60,000 phenotypic data points are available.
The data stock will be actualised and extended once every year.

#### Web application

The web interface of the MetaBrew database is accessible at
http://metabrew.ipk-gatersleben.de. It allows detailed browsing and
searching of data, user feedback and data export. There are navigation
tabs for traits, sources of data, cultivars, observations and
statistics, which open sub tabs each with several items. Data can be
grouped by cultivar, trait, year, row number or seasonal habit,
respectively. Statistical information such as standard deviation or
variance is given per trait and cultivar. All data can be exported to MS
Excel compatible files. Selective data can be visualised graphically
using scatter plots or box plots, respectively. Fig. 1 shows a
compilation of screenshots of the MetaBrew web application.

### Application of the MetaBrew database

MetaBrew is intended to assist brewers and maltsters to select the
optimal strain or cultivar for future breeding programmes or for
malting, respectively. Many detailed information about the performance
of specific traits for different cultivars are given. This helps to
predict promising crossing parents for breeding new barley cultivars.
Also, cultivars with good malting properties can be selected according
to this data in order to produce high quality beer.

By combining genotypic and phenotypic information, it is possible to
perform association studies in a large extent. Association studies will
show the impact of genetic changes in certain candidate genes on malting
parameters, which may be interesting not only for breeders but also for
the brewing industry. We are using MetaBrew for association studies on a
large subset of information contained in this database. First results
are described in (Matthies et al. 2009).

### Conclusion

In barley, general and specific information about malting and brewing
properties of single cultivars in a compact and structured way was
lacking. In this paper we presented the first version of the MetaBrew
database, a repository of comprehensive, high quality data about
phenotypic traits with impact on malting and brewing quality. The
structure allows data extraction according to the individual question of
interest of the user. MetaBrew is an ongoing project and currently
consists of a large collection of manually curated data. Information
content will be extended and actualised every year.

### Acknowledgements

We would like to thank Susanne Kirsten for excellent technical
assistance concerning data input.

### References

Fox, G., Panozzo, J., Li, C., Lance, R., Inkerman, P. and Henry, R.
2003. Molecular basis of barley quality. Australian Journal of
Agricultural Research 54(11&12):1081--1101.

Matthies, I., Weise, S. and Röder, M., 2009: Association of haplotype
diversity in the -amylase gene amy1 with malting quality parameters in
barley. Molecular Breeding, 23(1):139-152.

**Fig. 1** Compilation of screenshots of the MetaBrew web interface
showing (a) extracts from the database about cultivars and traits, (b)
correlation between two traits for a set of cultivars and (c) average
data of a trait.

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height="4.188888888888889in"}

![](media/image2.jpeg){width="6.497916666666667in"
height="4.205555555555556in"}

![](media/image3.jpeg){width="6.491666666666666in"
height="4.292361111111111in"}