Association between SSR Markers and Phenologic Plus Agronomic Traits in Barley (Hordeum valgare L.) Under Cold Stress Conditions

In the present study, the genetic diversity of 120 barley genotypes was investigated through 14 phenologic and agronomic traits as well as 50 SSR markers that cover the seven chromosomes of barley. In addition, the relationships between these marker loci and the studied traits were assessed via multiple regressions in two conditions. The field experiment was conducted in two planting dates, namely before the ideal time of the region planting date and the ideal planting date of the region in the experimental field of the Faculty of Agriculture and Natural Resources, Gonbad-e-Kavous University. A randomized complete block design with two replications was laid out for both planting dates. The results of cluster analysis based on SSR data classified the studied barley genotypes into six groups. For all the traits, except for spike length, more than one informative marker was detected. The results of stepwise regression analysis revealed significant associations between the traits and 60 SSR marker alleles under cold stress conditions. Under normal conditions, 63 SSR marker alleles showed a significant correlation with the studied traits. Among the 50 SSR markers, particular attention should be paid to a number of them, including the Bmag0211 marker with the highest coefficient of determination (R-2) in regression analyses of grain yield, 1000-kernel weight under non-stress conditions, and grain width and days to maturity under cold stress conditions as well as HVBM5A marker associated with spike length, 1000-kernel weight, and days to flowering under cold stress conditions. These markers may be a novel finding and relatively more reliable than the other identified markers. The informative markers could be suitable for marker-assisted breeding in barley after confirming them in other experiments.