Genetic resources and pangenome analysis of barley.

Barley (Hordeum vulgare) is widely cultivated, ranking fourth in cultivation area among cereal crops worldwide. Many wild and cultivated barley accessions have been collected and preserved in crop genebanks throughout the world. Barley has a large genome (~5 Gbp) that has recently been sequenced and assembled at the chromosome level by the international research community. The community also is sequencing accessions representing the diversity of both domesticated and wild barley to provide genome-wide genotyping information for pangenome analysis. Given that the pangenome represents the universe of genome sequences existing in a species, the long-term goal of this project is to obtain high-quality genome sequences of the major barley accessions worldwide. As each accession is annotated, the capacity to explore structural differences is enhanced by the increased understanding of the diversity of the barley genome, which will facilitate efficient development of cultivars for human consumption. This review describes our current knowledge of barley genome diversity and proposes future directions for basic and applied research of the barley pangenome.