Degree of phenotypic dominance of productivity features in spring durum wheat F1 hybrids

Purpose. To determine the degree of phenotypic dominance of F1 hybrids of spring durum wheat by plant height and grain weight per spike. Methods. The research was conducted in 2016, 2017 at the laboratory of spring wheat breeding of the V. M. Remeslo Myronivka Institute of Wheat with 42 F1 hybrids of spring durum wheat resulted from intraspecific hybridization on the diallel scheme. Field, laboratory and mathematical-statistical methods of research were used. Results. The amount of precipitation in 2016 approximated to the average long-term value, the hydrothermal coefficient corresponded to optimal humidity (HTC = 1.1). In 2017, high temperatures and uneven distribution of precipitation was observed (HTC = 0.96). It was established that the pattern of inheritance of plant height and the main yield component – grain weight per spike – in the F1 hybrids of durum spring wheat depends on the genotype and environment conditions. Significant variation in the degree of dominance (from negative overdominance to positive) indicates the complex nature of genetic determination of both plant height and grain weight per spike. In both years, in the hybrid combinations MIP Raiduzhna / Kharkivs’ka 39, Kuchumivka / MIP Raiduzhna, MIP Raiduzhna / Kuchumivka there was observed negative overdominance by plant height. It was noted weaker influence of meteorological conditions during growing season on pattern of inheritance of grain weight per spike, than plant height. In both years, in the hybrid combinations Zhizel / Terra, Zhizel / MIP Raiduzhna, Kharkivs’ka 39 / Spadshchyna, Kharkivs’ka 39 / Terra, Spadshchyna / MIP Raiduzhna, Spadshchyna / Kuchumivka, Spadshchyna / Tera, MIP Raiduzhna / Zhizel it was noted heterosis by grain weight per spike, which confirms high donor properties of the varieties Spadshchyna and Terra to improve spike productivity. According to complex of the features, the hybrid combination Spadshchyna / Terra was identified as the better one, because it demonstrated depression by plant height and positive overdominance by grain weight per spike. Conclusions. Analysis of F1 hybrids of durum spring wheat revealed different types of phenotypic dominance by plant height and grain weight per spike. Significant variation in the degree of dominance (hp) was observed, depending on specific feature, combination of crossing and environment conditions: from positive overdominance (hp > +1) to depression (hp < -1). The prospect of further research is selecting transgressive forms and evaluating the received recombinants for complex of agronomic features in order to create new source material and breeding varieties with high level of productivity and adaptability to adverse environmental conditions.