Aim. Study the reaction to photoperiod and identify Ppd-1 genotypes of modern alternative bread wheat varieties of various geographical origins. Methods. Plants growing under reduced and prolonged days, hybridological analysis of photoperiodic sensitivity of semi-diallelic F2 hybrids, calculations of average values, their errors and c2, multiplex STS-PCR with specific primers to the Ppd-D1 gene. Results. The phenotypic and genotype differences were detected, Ppd-1 genotypes of 10 alternative bread wheat varieties of different geographical origins were found. Conclusions. Afina, Palada, Solomia, Shestopalivka, Yara, Demir 2000, L897J23 varieties slowly or average react to reduce of day duration because of gene Ppd-D1a presence in their genotypes. Lastivka, Khutorianka, Zumoiarka varieties are highly photoperiodic sensitive genotypes and carriers of Ppd-1 genes recessive alleles only. From this view point, these three varieties correspond to the criteria of "typical alternative varieties".
Keywords: wheat, alternative varieties, photoperiodic sensitivity, DNA markers, gene, Ppd-1.