Fig. 1

Geographic coordinates, phylogenic and principal component analyses of the 562 hulless barley accessions. a Colored dots refer to the sampling regions of the barley accessions, while the color gradient corresponds to the number of accessions sampled in each region. b All 562 barley accessions were clustered into two apparent clades, colored red and blue, based on the structural analysis. c The first two principal components (PC) explained over 10% of the molecular variance and discriminated the whole population into three groups, which is largely consistent with the subpopulations inferred by structural analysis