A new genetic linkage map of barley (Hordeum vulgare L.) facilitates genetic dissection of height and spike length and angle

Plant height and spike length and angle are important agronomic traits in the production of barley (Hordeum vulgare L.) due to strong correlations with lodging and disease. The objective of this study was to use QTL analysis to identify genetic regions associated with each trait in a recombinant inbred line (RIL) mapping population derived from a cross of Falcon by Azhul. Falcon is a spring six-row hulless feed barley with long spikes displaying obtuse angles, while Azhul is a spring dwarf, six-row hulless food barley with short spikes displaying acute angles. The population was genotyped using SNP, DArT and SSR markers and quantitative trait loci (QTL) were detected on chromosomes 2H (102.8 cM, spike length), 3H (89.2 cM, plant height and 38.2, spike angle and length), 4H (19.0 cM, spike length), and 5H (106.7 cM, spike angle). In conclusion, we developed a barley genetic map, which incorporated SNP, DArT and SSR markers, for detection of height and spike length and angle QTL. Three spike angle, one spike length and one plant height QTL were novel and by using comparative genomics we identified possible candidate genes involved in gibberellic acid signaling and auxin- and ethylene-responsive pathways. This knowledge can be used to generate suitable markers for barley breeding improvement.