Seed dormancy in barley is dictated by genetics, environments and their interactions

The transition from dormancy to germination is crucial for malt barley in the malt house. Seed dormancy is a quantitative trait and the depths of dormancy controlled by environment/genetics remain unclear. Quantitative trait locus (QTL) analysis was conducted to evaluate the number, location and phenotypic variation explained by QTLs from data collected from different years, sites and germination conditions in the Stirling 9 Harrington population. QTLs on 4H, 5H and 6H could explain 25, 81 and 12 % of phenotypic variations, respectively. Consistent QTLs were detected on 5HL and other QTLs were subjected to growth or germination conditions. Germination tests under light detected more QTLs than in the dark. The QTL at 5HL were more important for seed dormancy under the Mediterranean environment and evidence showed at least two genes controlling seed dormancy at 5HL.