Apart from yield malting/brewing quality is the most important trait in any spring barley breeding program. Despite its salient importance, its quantitative inheritance so far prevented a detailed genetic analysis on the structural level. Therefore, the central goals of this proposal are (1) the identification of candidate genes using functional genomics approaches, (2) qtl mapping to integrate the results obtained from the functional analysis on the trait level (3) the analysis of the allelic diversity of malting related candidate genes. The identification of candidate genes will rely on two complementary approaches, a cDNA-array based functional association strategy and a novel cDNA-AFLP and SSH based procedure (marker assisted differential genotype screening, MAGS). For further genetic dissecting of the complex trait cis- and trans-factors will be identified using a genetical genomics strategy. In parallel, selected qtls from both cultivated and wild barley will be transferred into near isogenic backgrounds. Finally, the allelic diversity of selected candidate genes will be investigated by SNP analysis within a representative genotype panel.
The expected results will increase our understanding of the genes and metabolic pathways underlying malting quality. They will provide a contribution to understand and to further optimise the malting process also in the context of the use of germinating barley seeds as a production system. The findings will contribute to the development of new cultivars with improved physiological performance by exploiting the allelic diversity present in the primary gene pool of barley. In a generic context, we expect that the functional genomics methods to be developed for the identification of candidate genes in this study will be applicable to many other crop species and quantitative traits. Hence, barley serves for the present proposal both as a model and a target species.
To reach the goals mentioned above, GABI-Malt, a public private partnership has been formed to join the expertise of 4 research groups and 4 breeding companies (Fig. 1). They interact by generating plant material, performing trait analyses and field trials, the identification of candidate genes, genetic mapping and SNP analysis. The research program is split into 4 subprojects, which, based on their levels of application, were attributed to either research area one or two.
01.08.2004 - 31.07.2007