Purpose. To evaluate hazelnut cultivars, species and hybrids from the genetic collection of Corylus spp. in the National Dendrological Park “Sofiyivka” of the NAS of Ukraine for the complex of economic characters. An attempt has been made to analyze the information on Corylus spp. identity, taxonomy and description, dissemination and ecological requirements of the species, possibilities to use the genetic potential for developing new cultivars. Methods. The value of the Corylus spp. collection representatives was investigated using conventional testing procedures. For summarizing information concerning phylogenetic reconstruction of the Corylus L. genus and hazelnut, a number of scientific publications to be proposed for discussion was analyzed. The oil content in hazelnut kernels and the fatty acid composition was determined using official methods. Results. The best samples of hazelnut genetic collection were included into the broad hybridization programme, and C. chinensis Franch. representatives as well. A number of hybrid seedlings was obtained including new hazelnut cultivars ‘Sofiyivsky 1’, ‘Sofiyivsky 2’ and ‘Sofiyivsky 15’ which were characterized by spherical or almost spherical fruits, high winter hardiness and drought resistance, as well as the absence of rhythmicity in fruiting. Conclusions. The collection of varieties, forms, cultivars and species of the Corylus L. genus created during the last years can be the base for hazelnut breeding in Ukraine.

Purpose. Investigation of maize ae1 gene polymorphism by bioinformatic methods. Methods. Global and local alignment of the nucleotide and amino acid sequences, in silico translation and transcription, translates modeling, pri­mers design, phylogenetic analysis. Results. 255 nucleotide sequences of maize аe1 gene, 500 amino acid sequences of homology translates of maize ae1 gene (SBEIIb enzyme homologs) and 100 mRNA expressed from the maize ae1 gene were analyzed to establish phylogenetic relationships. Polymorphism of maize ae1 gene different regions was investigated by bioinformatic methods. Modeling of the maize enzyme SBEIIb was performed. Conclusions. According to the results of amino acid sequences of SBEIIb enzyme homologs alignment, it was found that ae1 gene orthologs are pre­sent only in monocots, paralogs – in monocots, dicots, and other taxa, including algae and animals. Based on the results of alignment of plants mRNA from which enzyme SBEIIb is translated, maize ae1 gene orthologs and the nearest paralogs encoding starch branching enzymes with chloroplast localization were defined; this suggests a possible origin of ae1 gene due to duplication of the gene encoding the 1,4-alpha-glucan-branching enzyme 2 with chloroplast or amyloplast localization. In the maize ae1 gene structure, regions were found that include polymorphic sites not defined previously. For the polymorphic sites design primers were developed that allowed to differentiate the maize lines. It was determined that the detection of polymorphism in theory can influence the enzyme function and, as a result, change the concentration of amylopectin in maize grain.

Purpose. To investigate rice blast resistance genes polymorphism by using bioinformatic methods. Methods. Global and local nucleotide alignment, phylogenetic analysis, HyPhy test. Results. For Pib gene, numerous single nucleotide substitutions and deletions of 1–3 bp were established. The phylo­geny of this gene has been studied and homologues have been found both in various rice species and in other cereals. These sequences can encode proteins that «recognize» the phytopathogens effectors, and can also be associated with resistance to phytopathogens. The Pi4 gene is characterized by single nucleotide substitutions, insertions and deletions; the number of non-synonymous substitutions exceeds the number of sy­nonymous ones. The Pi54 gene variability is significantly lower than that of the Pi4 and Pib genes. The predominant types of polymorphism were single nucleotide substitutions and small-sized indels. It was found that non-synonymous substitutions in Pi54, Pi4 and Pib genes were in close proximity, sometimes forming clusters, while some coding regions were either superconservative or contained predominantly synonymous substitutions. On philodendrograms, cultivated rice samples were clustered with samples of ancestral wild-growing species. Conclusions. Evolution of the rice blast resistance genes Pi4, Pib and Pi54 is characterized by diversification selection. Considering that tense coevolution and significant rate of adaptation and creation of new pathogen races are typical for a plant and a parasite, these genes are subjected to intensive selection aimed at increasing diversity for obtaining the resistance to new races of the pathogen.