Quantitative Trait Locus Analysis for Panicle and Flag Leaf Traits in Barley (Hordeum vulgare L.) Based on a High-Density Genetic Linkage Map

The yield of barley (Hordeum vulgare L.) is determined by many factors, which have always been research hotspots for agronomists and molecular scientists. In this study, five important agronomic traits related to panicle and flag leaf, including awn length (AL), panicle length (PL), panicle neck length (NL), flag leaf length (LL) and flag leaf width (LW), were investigated and quantitative trait locus (QTL) analyses were carried out. Using a high-density genetic map of 134 recombinant inbred lines based on specific-locus amplified fragment sequencing (SLAF-seq) technology, a total of 32 QTLs were identified, which explained 12.4% to 50% of the phenotypic variation. Among them, qAL5, qNL2, qNL3, qNL6, qPL2, and qLW2 were detected in 3 consecutive years and all of the contribution rates were more than 13.8%, revealing that these QTLs were stable major QTLs and were less affected by environmental factors. Furthermore, LL and LW exhibited significant positive correlations and the localization intervals of qLL2 and qLL3 were highly overlapped with those of qLW2 and qLW3, respectively, indicating that qLL2 and qLW2, qLL3 and qLW3 may be regulated by the same genes.