The thesis is devoted to the development, validation and application of biotechnology molecular markers for characterization of genes responsible for qualitative traits in wheat or barley varieties and hybrids. We picked up the optimal biotech approaches to identify allelic variants of high molecular weight glutenin (HMWG) genes of wheat, wheat-rye translocations and genes of polyphenol oxidase activities in wheat grains, and 3 important loci of barley brewing features. On the base of those we designed a number of multiplex polymerase chain reactions (PCR) using reference genes in wheat and barley and sometimes coupled with restriction analysis. With the help of developed molecular markers systems we analyzed Ukrainian and foreign varieties originated from different breeding centers to identify the distribution of alleles of Glu-1 locus which lead to high baking quality. It was found that allele Glu-A1b was present in 79 varieties (55.2%). The allele Glu-B1al was determined in 12 varieties. For the variety Kyivska ostysta a new amplicon of 700 base pairs had been discovered. It indicated the change of genetic make-up of Matrix Attached Region inside the promoter of Glu-B1 locus, and thus a new allele of this locus. The allele Glu-D1d valuable for baking quality was detected in 121 varieties, representing 84.6%. The allele Glu-D1a was identified in 22 varieties (16.4%). The Glu-D1a allele was expressed in varieties from Kyiv, Myronivka, and abroad. In contrast, the Glu-D1d allele was identified in varieties derived from SGI (Odesa) breeding center only. Four duplex PCRs with specific primers were developed for the detection of wheat-rye translocations. The validation of DNA markers to identify wheat-rye translocations was carried out by analyzing the gliadin grain storage proteins and studying different samples of breeding hybrids. 31 varieties out of collected 143 varieties were found to have wheat-rye translocations of different types, representing 21.7% of the total. Of those, 21 (14.7%) was shown to possess the 1AL.1RS translocation while in 10 varieties (7%) the 1BL.1RS was present. For efficient detection of all possible known alleles of genes that determine polyphenol oxidase activities of wheat the PPO33 marker (for gene Ppo-A1) and the PPO29 marker (for gene Ppo-D1) were selected. In the current study the Ppo-A1b allele was found in varieties Yednist and Bilyava only, representing just 2.4% of the total. Heterogeneity of the material was observed in 26 samples (18.2%), i.e. the presence of both alleles of the gene simultaneously. The allele Ppo-A1a determining the polyphenol oxidase activity of wheat was detected in the other varieties. The Ppo-D1a allele was found in 49 varieties (34.3%), which led to low polyphenol oxidase activity in wheat grain, while the Ppo-D1b allele was typical for the other varieties. The white-grained lines and amphiploids were tested using the developed marker systems and the prevalence of alleles of the Ppo genes had been shown. Both phenol as well as L-DOPA was used as substrate for measuring polyphenol oxidase activities in grain of contrasting varieties and white-grained wheat lines. It was showed that varieties and lines of genotype Ppo-A1b, Ppo-D1a had a quite low level of polyphenol oxidase activities. The varieties containing Ppo-A1a/b, Ppo-D1a alleles also showed low levels of activity, unlike the varieties with Ppo-A1a/b, Ppo-D1b alleles. These results stated the heterogenic varieties of Ppo-A1 gene led to reduced activity of polyphenol oxidase enzymes while at the same time the functional allele Ppo-D1b determined the high polyphenol oxidase activity. The wheat varieties with genotypes Ppo-A1a, Ppo-D1a and Ppo-A1a, Ppo-D1b had significantly higher levels of polyphenol oxidase enzymatic activity. However, in both genotypes there were varieties with almost the same level of activity. It showed essentially a major role of Ppo-A1a allele in creating high polyphenol oxidase activities in wheat and supportive role of Ppo-D1a allele, which clearly revealed its phenotypic effect only if Ppo-A1b allele or heterogeneity were present in the material. Considerable heterogeneity was revealed in the source material of wheat, used for the manufacturing of Ukrainian food. A number of DNA markers were selected to detect the alleles of bmy1, Lox-1 and Itr1 genes in barley varieties suitable for brewing. A comprehensive assessment of barley varieties in three important features: thermal ?-amylase (gene Bmy1), the activity of lipoxygenase-1 (gene Lox-1) and accumulation of SE protein (gene Itr1), which causes clouding of beer during storage were carried out. By using the conventional and multiplex PCRs the screening of domestic and foreign barley varieties was conducted and the prevalence of allele of studied genes for beer brewing was determined. The system of DNA markers allowed us to identify the best varieties of barley for brewing. These varieties are expected to be involved in breeding schemes with Ukrainian local varieties. The proposed approach intensifies the process of creating new domestic crop varieties with desirable brewing characteristics.
