Worldwide phylogeography and history of wheat genetic diversity

Since its domestication in the Fertile Crescent ~8,000 to 10,000 years ago, wheat has undergone a complex history of spread, adaptation and selection. To get better insights into the wheat phylogeographyand genetic diversity, we describe allele distribution through time using a set of 4,506 landraces and cultivars originating from 105 different countries genotyped with a high-density SNP array. Although the genetic structureof landraces is collinearto ancient human migrationroads, we observe a reshuffling through time, related to breeding programs, with the apparition of new alleles enriched with structural variationsthat may be the signature of introgressionsfrom wild relatives after 1960.