Genomics-Based Barley Breeding

Abstract

The creation of the first barley reference genome opens up new and improved avenues for the translation of genetics and genomics to application in plant breeding. Despite steady progress in barley breeding, there is still a great need for improved barley cultivars that provide raw materials for a wide array of products, are adapted to diverse growing conditions, and provide sustainable and profitable income for farmers. In this chapter, we investigate some of the major challenges in barley breeding and describe how our ever-increasing understanding of the barley genome has led to new methods and approaches to meet those challenges. There are several excellent reviews of barley breeding that detail progress in breeding over time (e.g., Friedt et al. 2010). Here, we will focus on how genetic tools and resources have affected progress so far and the prospects to utilize current and emerging genomic tools to sustain barley improvement. In particular, we explore the evolution of marker development for mapping, genomic approaches to selecting parent combinations and from within segregating breeding populations, exploiting diverse germplasm, tapping into genomic regions of limited recombination, and utilizing bioinformatic characterization of genetic load. Access to a complete reference genome is already providing breeders and geneticists information about candidate genes for QTL that are targets for marker-assisted selection, the physical order of genetically linked markers in regions explored by fine mapping, and the ultimate consensus map with which to compare mapping studies. Additional full genome sequences leading to a pan-genome for barley, refinement of the reference genome, and new tools to access, analyze, and utilize genomic information will foster further integration of genomics into barley improvement.