The influence of genotype and conditions of the year on the inheritance of productive bushiness at hybridization of soft winter wheat cultivars that differ in early maturation

Abstract

The peculiarities of inheritance of productive bushes in F1, obtained by cross-breeding of different cultivars of soft winter wheat were studied in the conditions of the experimental feld of the Research and Production center of the Bila Tserkva National Agrarian University in 2018–2020 contrasting in the hydrothermal conditions. During the research years, the productive bushiness of selected parental forms for hybridization had a signifcant differentiation of 1.1–2.2 pieces of stem/plant. The varieties formed maximum average productive bushiness (1.7 pcs. stalk/plant) in 2020, and in 2018–2019 the indicator was at the level of 1.5 pcs. stalk/plant. Research has shown that winter wheat productive bushiness is a genetically controlled trait and is highly susceptible to the conditions of the year. The vast majority of hybrids produced in 2018– 2020 signifcantly exceeded the original forms for productive bushing (2.3–7.6 pcs. stalk/plant). The maximum F1 index (4.7 pcs. stalk/plant) was formed in 2019. Under 2018 conditions, the productive bushiness represented 4.1 pcs. In 2018 conditions, the productive bushiness represented 4.1 pcs. stalk/ plant. The minimum productive bushes of 2.8 pcs. stalk/ plant in the hybrid crop were formed in 2020. The results show that the productive bushiness F1 depends on the components of hybridization and the conditions of the year. Positive hypothetical and true heterosis for three years are determined in 34 and 32 of 36 combinations of hybridization, respectively. Stable high hypothetical (307.7–105.4 %) and true (278.6–100.0 %) heterosis, for 2018–2020, was in Bilotserkivska semi-dwarf / Zolotokolosa, Bilotserkivska semi-dwarf / Chornyava, Bilotserkivska semi-dwarf / Vidrada, Zolotokolosa / Chornyava, Zolotokolosa / Vidrada. Studies have found that positive overdominance is the most common type of inheritance of productive bushiness in 2018–2020 observed in 95.1 % of hybrids. However, indicators of phenotypic dominance of productive bushiness in the research years are determined by selected components of hybridization and the conditions of the year. The experimental data indicate that the crossbreeding of soft winter wheat varieties that differ in early maturity of parental forms of made it possible to isolate hybrids, which in contrasting hydrothermal conditions for the growing season years have formed stable high manifestations of productive bushiness. Key words: soft winter wheat, parental forms, hybrids, productive bushiness, hypothetical and true heterosis, degree of phenotypic dominance, type of inheritance.