The presented study analyzed the inheritance via heterosis of interspecific F₁ hybrids between durum and bread wheat over better parents and ratios of dominance for spike-related traits affecting their productivity and transmission to future segregating populations. The research transpired in the crop seasons of 2017–-2019 at the Institute of Molecular Biology and Biotechnologies, Azerbaijan National Academy of Sciences, Baku, Azerbaijan. The hybridization program used eight durum wheat (Triticum durum Desf) genotypes, i.e., Shark, Karabagh, Barakatli-95, Tartar, Garagilciıg-2, Vugar, Mirbashir- 50, and Shiraslan-23, and 13 bread wheat (T. aestivum L.) cultivars, viz., Mirbashir-128, Kyrmyzygul-1, Gobustan, Layaqatli, Kyzyl Bughda, Gunashli, Taleh-38, Sheki-1, Murov, Nurlu-99, Aran, and two foreign cultivars Bezostaya-1 (Russia) and Dagdash (Turkey) to generate 24 interspecific F₁ hybrids. Studying the heterosis over better parents and degree of dominance in these interspecific F₁ hybrids compared their performance with parental genotypes for spike-related traits, i.e., spike length, spikelets per spike, grains per spike, and grain weight per spike. In the F₁ interspecific hybrids’ evaluation, the recorded desirable positive heterosis over better parents and dominance ratios appeared in cross combinations, i.e., Barakatli-95 × Gobustan, Karabagh × Mirbashir-128, Karabagh × Shark, Sheki-1 × Gobustan, Murov × Daghdash, Nurlu-99 × Layaqatli, Gobustan × Sheki-1, and Mirbashir-50 × Shiraslan-23 for spike-related traits. However, the F₁ hybrid Garabagh × Gobustan revealed negative heterosis and depression for yield-related traits.

Keywords: Interspecific wheat hybrids (T. durum × T. aestivum), parental genotypes, heterosis, dominance, spike-related traits, productivity

Key findings: The study identified the promising durum by bread wheat F₁ hybrids in terms of heterotic and dominance effects over better parents for yield indicators that can benefit future breeding work to obtain high-yielding wheat genotypes.