From Domestication to Genome Editing: The Evolution and Future of Barley Breeding

Evolution and Future of Barley Breeding

Abstract

Barley is one of the world’s most important cereal crops, with critical roles in malting, animal feed, and human nutrition across diverse agro-ecological regions. Over the past century, barley breeding has evolved from phenotype-based selection to a highly data-driven technologies enabled by genomics and precision breeding. Recent phylogeography evidence indicated that domesticated barley possesses a mosaic genomic ancestry derived from multiple Hordeum vulgare ssp. spontaneum populations across the Fertile Crescent, Eastern Iran, Central Asia, and the Tibetan Plateau, challenging earlier single-origin domestication models. This genetic complexity highlights the continuing importance of wild and landrace as reservoirs of alleles for abiotic stress tolerance, disease resistance, and grain quality. It severs as a diploid model of the Triticeae tribe with relatively small genome (~5.3 Gb), resolved to near telomere-to-telomere continuity through the Morex V3 reference assembly. It has accelerated gene discovery, structural variant characterization, and the development of molecular breeding tools. This review synthesizes current knowledge on barley phylogeography and domestication, genomic architecture, breeding objectives, and technological milestones, with emphasis on modern barley improvement strategies including genomic selection, speed breeding, and genome editing. We also discuss future prospects for climate-resilient barley improvement in the era of artificial intelligence–assisted breeding and CRISPR-based precision genetics.