Purpose. Analysis of the allelic state of Ppd-1 genes, which control sensitivity to photoperiod, in varieties and lines of bread winter wheat, and comparison of the results obtained with field observations on the duration of periods before heading and flowering, whose originators were the Nosivska Breeding and Research Station of the V. M. Remeslo Myronivka Institute of Wheat National Academy of Agrarian Sciences of Ukraine and Poltava State Agrarian Academy of the Ministry of Education and Science of Ukraine. Methods. The following methods were used in the work: DNA extraction, allele-specific PCR, agarose and polyacrylamide gel electrophoresis, analysis of variance. Results. It was revealed that ‘Yuvivata 60’ variety has a recessive Ppd-1 genotype and belongs to the III haplotype by a combination of mutations in the structure of Ppd-D1 gene. Line ‘L41/95’ was heterogeneous by alleles of Ppd-D1 gene, which corresponded to the presence of haplotypes III and VII. All other tested cultivars and lines were characterized by alleles Ppd-A1b, Ppd-B1b and Ppd-D1a, and assigned to haplotype VII. According to the results of statistical data processing, the duration of the period from May, 1 to heading was the smallest for the variety ‘Donskaya polukarlikovaya’ in the conditions of both the Forest-Steppe and Polissia-Forest-Steppe regions of Ukraine, the longest – in the varieties ‘Yuvivata 60’, ‘Myronivska 61’ and ‘L41/95’. The differences between these groups were significant and amounted to 10 days. Conclusions. A breeding material with a high adaptive ability for growing conditions in Polissia-Forest-Steppe zone was studied by the allelic state of the Ppd-1 genes. A low level of polymorphism in the studied varieties and lines was revealed by the alleles of Ppd-1 genes [12.5% – Ppd-D1b (²²²), 12.5% – Ppd-D1à/b (²²²/VII), 75% – Ppd-D1a (VII)], that agrees with the hypothesis that breeders gave a greater preference for the photoperiod-insensitive wheat genotype under Ukrainian conditions. The genotypes with the dominant Ppd-D1a (VII) gene almost completely dominate in the south of Ukraine. At the same time, in northern latitudes, weather conditions negate the advantages of the genotypes with Ppd-D1a gene