Association mapping for drought tolerance in barley at the reproductive stage

Drought is an important abiotic stress causing the major crop losses worldwide. Identification of genomic regions associated with drought-related traits is essential for improving drought tolerance in barley. Association mapping was implemented to investigate the associations between 76 SSR markers and six drought-related traits on a set of 107 barley accessions evaluated under well-watered and drought-stressed conditions. Highly significant differences between well-watered and drought-stressed conditions were observed in all measured traits. A high level of polymorphism with SSR markers was observed. A total of 36 significant marker-trait associations for drought-related traits were detected. A high extent of significant LD (> 61%) was observed between markers on different chromosomes, suggesting epistatic interaction. Several molecular markers are significantly associated with more than one phenotypic trait, suggesting the possible presence of pleiotropic or indirect effects. The phenotypic variation, explained by individual marker-trait associations, ranged from 6.33% to 35.78%.