The paper reveals the results of study on the parent components of soft winter wheat selection of the V.M. Remeslo Myronivka Institute of Wheat of the National Academy of Sciences of Ukraine and the Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine. The fndings demonstrate dependence of grain formation in the frst generation of interspecifc hybrids of soft winter wheat on the environmental factors and on wheatrye translocations 1AL.1RS and 1BL.1RS in the parental forms. The results of the analysis of variance show that the efciency of crossing and the percentage of grain formation signifcantly in the feld depended on the interaction of factors (47.7 %, p ≤ 0.05), on weather conditions (30.4 %) and the variety genotype (21.5 %) and did not depend signifcantly (0.4 %) on unaccounted factors (coincidence of flowering dates of the components involved in hybridization). In the group of crosses 1BL.1RS / 1BL.1RS, the average percentage of grain formation was the highest for three years (2016– 2018) and did not differ signifcantly – 50.1 %; 55.5 % and 49.8 %. The maximum average indicators for the research years (48.3 %) and under favorable weather conditions of 2017 (68.3 %) were obtained using the crosses of the variety of Svitanok myronivskyi 1BL.1RS as a parent form, and the minimum (37.1 % and 45.2 %, respectively) – using the variety of Kalynova 1BL.1RS. The results of the study show that hybrid combinations of Svitanok myronivskyi / Kalynova (56.1 %), Lehenda myronivska / Kalynova (54.6 %), Zolotokolosa / Svitanok myronivskyi (53.3 %), Lehenda myronivska / Ekspromt (52.4 %), Kolumbia / Zolotokolosa (48.1 %), Svitanok myronivskyi / Lehenda myronivska (47.6%) and Svitanok myronivskyi / Zolotokolosa (46.4 %) were the best in terms of the average percentage of grains formation for the research years.
Key words: soft winter wheat, wheat-rye translocations, grain formation, weather conditions, genotype.
