Exploring the relationship between grain yield and heading date traits and their
stability parameters at phenotypic, genetic, and molecular levels is the milestone for
improving yield and adaptation in barley. We evaluated a mapping population
comprising 298 doubled haploid lines in multienvironmental trials in Egypt.
Composite interval mapping revealed 35 quantitative trait loci (QTLs) with four
pleiotropic QTLs. A major QTL bPb-9110 (140.3 cM on 3H) with a peak LOD greater
than 24 was found to be associated with the stability statistics bi and R2 of heading
date. Additionally, the marker bPb-1213 on 1H was correlated to heading date, grain
yield, and the statistic bi (GYP). We also found that the gene HvFT4 (2H, 66 cM) had
a significant impact on the heading date due to the presence of exotic alleles. This
gene was closely linked to the photoperiod Ppd-H1 gene by 24.9 cM, and both genes
play a major role in regulating flowering time in barley. Our results provide evidence
that stability statistics pinpoint genetic control and appear promising for
marker-assisted selection.