Bakuma A. Genetic polymorphism of Ppd loci and photoperiod sensitivity of modern Ukrainian bread wheat varieties

The presented work is dedicated: to the studying of allelic diversity of photoperiod sensitivity genes Ррd-1 in the genotypes of modern bread winter wheat varieties, created in different breeding centers of Ukraine and to the investigation of the effects of alleles of Ррd-D1 gene on vegetation rates and agronomic traits of wheat plants. By using PCR-analysis with allele-specific primers for alleles of Ppd-1 genes the haplotype composition of the Ррd-D1 gene and the allelic characteristics of Ppd-1 genes were revealed in 94 modern bread winter wheat varieties from institutions and breeding centers, which are located in Polesie, Forest steppe and Steppe zone of Ukraine. The data base of studied wheat varieties was created. In all investigated wheat varieties were presented recessive Ppd-A1b and Ppd-B1b, for which absence of deletion 1085 bp and insertion 308 bp in the promotor regions have been revealed, respectively. In the genotype of wheat variety Antonivka we have detected three copy of Ppd-B1b like in Sonora64. In all agro-climatic zones of Ukraine genotypes with dominant Ppd-D1a allele exceeded recessive genotypes. The ratios of genotypes with Ppd-D1а, Ppd-D1b alleles and heterogeneous by Ppd-D1 locus were 90%, 8% and 2%. In genotypes of bread winter wheat varieties of Forest steppe of Ukraine, that turned out to be the most polymorphic by haplotype composition of Ppd-D1 gene, were detected haplotypes VІІ (91 %), ІІІ (5 %), IV (3 %) та ІІ (1 %). By using RAPD-, IPBS-, SSR-analysis, allele-specific PCR and according to the scheme of crossing and selection was proved, that Kooperatorka and Kooperatorka rannia are near-isogenic lines, that differed by Ррd-D1b / Ррd-D1a alleles, and Stpenyak 1 and Stepnyak 1 ranniy are wheat analogue-lines, that differed by Ррd-D1b / Ррd-D1a and Rht8а / Rht8с alleles. The effects of Ppd-D1a and Ррd-D1b alleles on 11 agronomically important wheat traits in conditions of South steppe of Ukraine and photoperiodic sensitivity in conditions of Forrest steppe were revealed on bread winter wheat near-isogenic lines and analogue-lines. The obtained in the dissertation data fill the information gap on allelic characteristics of photoperiodic sensitivity genes of modern Ukrainian wheat varieties, enrich information on wheat genetic resources in the Ukraine, and contribute to the involvement of marker selection in the breeding process.