Genome-Wide Association Mapping for Kernel and Malting Quality Traits Using Historical European Barley Records
van Eeuwijk F (2014) Genome-Wide Association Mapping for Kernel and Malting Quality Traits Using Historical
European Barley Records. PLoS ONE 9(11): e110046. doi:10.1371/journal.pone.0110046
Genome-Wide Association Mapping for Kernel and Malting Quality Traits Using Historical European Barley Records
Inge E. Matthies 0
Marcos Malosetti 0
Marion S. Ro der 0
Fred van Eeuwijk 0
James C. Nelson, Kansas State University, United States of America
0 1 Department of Gene and genome mapping, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) , Gatersleben, Sachsen-Anhalt, Germany, 2 Biometris , Wageningen University and Research Centre , Wageningen, Gelderland , The Netherlands
Malting quality is an important trait in breeding barley (Hordeum vulgare L.). It requires elaborate, expensive phenotyping, which involves micro-malting experiments. Although there is abundant historical information available for different cultivars in different years and trials, that historical information is not often used in genetic analyses. This study aimed to exploit historical records to assist in identifying genomic regions that affect malting and kernel quality traits in barley. This genomewide association study utilized information on grain yield and 18 quality traits accumulated over 25 years on 174 European spring and winter barley cultivars combined with diversity array technology markers. Marker-trait associations were tested with a mixed linear model. This model took into account the genetic relatedness between cultivars based on principal components scores obtained from marker information. We detected 140 marker-trait associations. Some of these associations confirmed previously known quantitative trait loci for malting quality (on chromosomes 1H, 2H, and 5H). Other associations were reported for the first time in this study. The genetic correlations between traits are discussed in relation to the chromosomal regions associated with the different traits. This approach is expected to be particularly useful when designing strategies for multiple trait improvements.
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Funding: This study was supported by a grant from the Federal Ministry of Education and Research (BMBF) within the GABI program (GENOBAR, project
No. 0315066C). The work of Marcos Malosetti and Fred van Eeuwijk was supported by the Generation Challenge Program (GCP), project No. 221. The funders had
no role in study design, data collection or analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have the following interest: Triticarte Pty. Ltd (Canberra, Australia) provided the DArT analyses as a service to the authors.
This does not alter the authors adherence to all the PLOS ONE policies on sharing data and materials.
. These authors contributed equally to this work.
Barley (Hordeum vulgare L.) is a major cereal crop in Europe. It
ranks fourth in worldwide production, after wheat, rice, and
maize. It is grown for feed, food, and malting. Most of the malt
produced is used for brewing beer and, to a lesser extent, for
distilling (e.g., whiskey). In Europe, two-rowed spring cultivars are
used mainly for malting and brewing; six-rowed winter barleys are
predominantly used for food. However, six-rowed barley has been
increasingly used for malting in Europe, following the trend started
in the US. Therefore, depending on the end-use, there are two
primary aims in breeding barley: 1) superior food and feed quality
with high protein content, and 2) high malting quality with high
starch and low protein contents. Improving the malting quality is a
central goal in breeding, in addition to improving the yield of
barley. Malting quality is a complex trait, because it consists of
several components, and all are polygenic. Moreover, the
definition of high malting quality is not straightforward; it depends
on the processing and brewing methods. In general, the main
breeding goals for malting barley are high malting extract, low
protein content, good solubility properties, good kernel formation,
and low glume content.
For the past 80 years, to optimize the malting traits in barley,
breeders mainly focused on a narrow gene pool of spring barley
types [1]; the most important quality parameters to optimize were
the amounts of soluble protein, extract, raw protein, and friability.
Further improvements in malting quality must rely on new
combinations of genes and germplasms. Molecular marker-assisted
selection (MAS) schemes have been applied to developing barley
varieties with improved malting quality traits. Those studies have
identified many quantitative trait loci (QTL) in barley [24]. MAS
strategies have facilitated gene pyramiding techniques to acquire
advantageous alleles from different loci. With MAS, the breeding
efficiency can be improved by eliminating undesired genotypes at
early stages, which can reduce time and costs [47]. The
genomewide association approach provides a good basis for selection
strategies (...truncated)