Salinity is one of the major environmental factors that negatively affect crop development,
particularly at the early growth stage of a plant and consequently the final yield. Therefore, a set of
50 wild barley (Hordeum vulgare ssp. spontaneum, Hsp) introgression lines (ILs) was used to detect
QTL alleles improving germination and seedling growth under control, 75 mM, and 150 mM NaCl
conditions. Large variation was observed for germination and seedling growth related traits that
were highly heritable under salinity stress. In addition, highly significant differences were obtained
for five salinity tolerance indices and between treatments as well. A total of 90 and 35 significant
QTL were identified for ten investigated traits and for tolerance indices, respectively. The Hsp
introgression alleles are involved in improving salinity tolerance at forty (43.9%) out of 90 QTL
including introgression lines S42IL-109 (2H), S42IL-116 (4H), S42IL-132 (6H), S42IL-133 (7H), S42IL-
148 (6H), and S42IL-176 (5H). Interestingly, seven exotic QTL alleles were successfully validated in
the wild barley ILs including S42IL-127 (5H), 139 (7H), 125 (5H), 117 (4H), 118 (4H), 121 (4H), and
137 (7H). We conclude that the barley introgression lines contain numerous germination and seedling
growth-improving novel QTL alleles, which are effective under salinity conditions.