The presented study comprehensively assessed barley (Hordeum vulgare L.) hybrid populations of F₃–F₅ generations, comparing with the standard barley cultivars, Karagaydinckiy-5 and Astana-2000. The crossing of isolated barley cultivars of the international collection (obtained from Australia) proceeded under intense continental climatic conditions of Northern and Central Kazakhstan. Barley promising selected populations, i.e., Macguarie × Arna, Flinders × Tselinniy golozerniy, and Flinders × Omskiy golozerniy, showed early maturity (79–83 days), superior plant height (34.4–69.5 cm), and enhanced 1000-grain weight (56.6 g, 56.4 g, and 58.0 g, respectively), and populations, viz., Buloke × Karagandinckiy-6, Fathom × Donezckiy-9, and Onslow × Karabalykckiy-43, for productivity (1 m²) at 184 g, 116.4 g, and 140.1 g, respectively. Identified in the study were the correlation of productivity and its structural elements, particularly the grain weight per ear (r = 0.486) and grain weight per plant (r = 0.828), mainly determining grain productivity. The determination of structural features variation showed a significant excess (more than 20%) with varying levels. The level of variability of grain mass per plant has shown in hybrid lines, i.e., Fathom × Karagandinckiy-5, Onslow × Karagandinckiy-10, Admiral × Karabalykckiy-150, and Admiral × Donezckiy-9. In grains, the protein content ranged from 10.45% to 16.63%, and the excess over the standard cultivar resulted in the hybrid lines Franklin × Sabir (16.63%), Anodolu-86 × Donezckiy-8 (16.04%), and Flinders × Omskiy golozerniy (15.31%). Based on an average of the study years, the drought-resistant and high-productivity hybrid lines were Buloke × Karagadinckiy-6, Fathom × Donezckiy-9, Onslow × Karabalykckiy-43, Onslow × (Karagandinckiy-5 × Аrna), Bass × Karabalykckiy-150, Granal × CMB93H-805-F-1Y-1M-OY-17TRS-OAP, and Granal × CMB89A-380-1M-OGH-105GH-1B-1OY-OAP-19AP-OAP. These promising genotypes can benefit the development of drought-resistant and high-yielding barley cultivars through future breeding programs under prevailing environmental conditions.

Keywords: Barley (Hordeum vulgare L.), hybrids, breeding, drought, traits association, yield-related traits, protein content

Key findings: The study based on hybrid populations of world genetic resources of barley (Hordeum vulgare L.) under existing environmental conditions makes it possible to select and develop drought-resistant and high-yielding spring barley cultivars through the conventional breeding program and provide food security to the Republic of Kazakhstan.