Barley Domestication History: A Puzzle with Many Pieces

Archaeobotanical remains indicate that before barley was domesticated, Neolithic humans utilized wild barley across a broad geographic region, including areas east of the core range of wild barley in the Fertile Crescent. To better understand the genetic contributions of wild populations to domesticated barley, we compare SNP frequencies from 803 barley landraces (locally cultivated varieties) to a sample from wild populations and find that the genetic contribution of individual wild populations differs across the genome. Despite extensive migration and admixture of barley landraces since domestication, individual landrace genomes indicate a pattern of shared ancestry with geographically proximate wild barley populations. This results in landraces with a mosaic of ancestry from multiple source populations rather than discrete centers of origin. These results are consistent with the broad pattern of utilization of wild populations indicated by archaeobotanical evidence.