Identification of DNA markers associated with phenological traits in spring barley (Hordeum vulgare L.) under drought stress conditions

Drought is one of the important abiotic stresses that affects the phenological stages and crop productivity. Phenological stages can seriously influence the crop yield and quality. In this study, phenological traits including days to germination, days to tillering, days to stem elongation, days to head emergence, days to dough development in kernel, days to physiological maturity, number of grains per spike, thousand kernels weight, grain yield were evaluated in 148 commercial barley cultivars in both years under normal and drought stress conditions. In molecular experiment, the molecular profile of barley cultivars was assessed by 14 AFLP primer combinations and 32 SSRs loci. The phenotypic results showed the high level of diversity between studied cultivars. The studied barley cultivars were divided into two subgroups. Linkage disequilibrium analysis revealed that r(2) values among all possible markers pairs have an average value of 0.0178. Mixed linear model procedure showed that totally, 137 loci had significant association with nine investigated traits under normal and drought stress conditions. The identified markers potentially can be used in marker-assisted selection in barley drought resistant breeding programs.

Automated summary

The study evaluated phenological traits of 148 commercial barley cultivars under normal and drought stress conditions, identifying high diversity among the cultivars through molecular and phenotypic analysis. A total of 137 loci were found to have significant associations with nine traits under both conditions, suggesting potential use in marker-assisted selection for barley drought resistance breeding programs.