The project aims at a comprehensive understanding of the gene expression networks controlling seed traits. Based on a genetical genomics approach, a set of about 100 introgression lines representing the whole wild barley (Hordeum spontaneum) genome introduced into a spring barley (H. vulgare, variety Brenda) background will be characterized by transcriptional, protein and metabolite profiling. The experimental set-up allows large-scale calculations of e(xpression)QTLs, based on a ca. 12,000 unigene array of exclusively seed-expressed genes, but also calculations of QTLs for proteins and metabolites. Coupled with large-scale gene mapping and available data of QTLs of agricultural traits, a unique data set will be created on trait-related genes and pathways for present and future molecular breeding projects. In addition, regulatory networks of seed development will be defined. All together the expected results will enable the development of cause-related molecular breeding strategies involving genetic engineering and/ or marker-assisted selection with markers derived from the project.