Breeding and genetic peculiarities of spring barley 1000 kernel weight under conditions of the central part of the Ukrainian Forest-Steppe

Purpose. To reveal the breeding and genetic peculiarities for spring barley 1000 kernel weight and to identify genetic sources for breeding under conditions of the central part of the Forest-Steppe of Ukraine. Methods. Investigations were carried out at the V. M. Remeslo Myronivka Institute of Wheat of the NAAS of Ukraine. Spring barley F1 of two comp­lete (6 ´ 6) diallel crossing schemes was investigated. The first scheme included modern both domestic and foreign spring barley malting varieties (‘MIP Tytul’, ‘Avhur’, ‘Datcha’, ‘Quench’, ‘Gladys’, ‘Beatrix’), the second – classic covered awned (‘MIP Myroslav’, ‘Sebastian’), awnless (‘Kozyr’, ‘Vitrazh’) and naked (‘Condor’, ‘CDC Rattan’) varieties. Results. Various types of inheritance of 1000 kernel weight were revealed, with the exception of negative dominance. The proportion of combinations with corresponding values of the degree of phenotypic dominance varied depending on the genotypes involved in the crossing and the years of testing. In both crossing schemes, both in 2019 and in 2020, positive overdominance was found in most combinations. The grea­test number of combinations with the manifestation of hete­rosis under different growing conditions was noted when varieties ‘Gladys’ and ‘MIP Myroslav’ were used in crossing. According to the parameters of genetic variation, it was revealed that the trait was determined mainly by the additive-dominant system. The dominance was aimed at increasing the 1000 kernel weight. Only in the second crossing scheme in 2019 the value of the directional dominance indicator was unreliable. In the loci, incomplete dominance in 2019 and over-dominance in 2020 were revealed. Reliably high effects of the general combining ability in both years were noted for varieties ‘Datcha’, ‘Gladys’, ‘MIP Myroslav’, ‘Kozyr’ and ‘Vitrazh’. Conclusions. The revealed breeding and genetic peculiarities indicate that for the overwhelming majority of created hybrid combinations will be required the final selection in later generations, when the dominant alleles are homozygous. Spring barley awned varieties ‘Gladys’, ‘MIP Myroslav’ and ‘Datcha’, as well as awnless varieties ‘Kozyr’ and ‘Vitrage’ can be used as effective genetic sources for increa­sing the 1000 kernel weigh