Purpose. To define morphological peculiarities of the different types of shoots of switch grass (Panicum virgatum L.) in the context of introduction in the Right-Bank Forest-Steppe and Polissia zones of Ukraine. Methods. Morpho-physiological and ontogenetic analysis, morphometric technique, statistical evaluation. Results. It was found that P. virgatum plants were producing the following types of shoots: vegetative-generative short or long rhizomatous ones (they appeared as in the underground part of a maternal shoot in «the area of shortened internodes» and in the base of its aboveground part); vegetative underground and aboveground ones (they are forming both in the axils of scales of the underground part of a maternal shoot and in the axils of cauline leaves); generative aboveground shoots (borne in the axil of cauline leaves). Morphological parameters and features of morphogenesis of reproduction, resting and secondary buds have been described. Conclusions. During flowering phase of maternal shoot, P. virgatum reproduction buds were on the organogenesis phase I–II, their bursting occured after maternal shoot has flowered. The correlation of internodes length, leave blades and sheaths has been established. The maximum values of the above parameters were observed in the middle part of the prefloral zone of the stem. In the context of introduction, panicle earing came in the third decade of July, flowering began in the first decade of August. It was revealed that complete flowers are bloomed faster than the staminate ones.

Purpose. Identifying the features of the seasonal growth rhythm, development of the plants, morphological and biological differences in monoecious introduced and domestic varieties of Cannabis sativa L. in the North-east region of Ukraine. Methods. The research was conducted from 2014 till 2019. The following research methods were employed: field (phenological observations, sampling for laboratory analysis), microscopic (study of the morphological structure of glandular and cystolithic hairs on vegetative and generative organs, determination of the size and density of hair formation), laboratory and analytical (determination of the content of cannabinoid substances by thin layer and gas-liquid chromatography), biomorphological me­thods (analysis of morphological characteristics of plants). Chemical analysis for the content of cannabinoid substan­ces was carried out in the laboratory of the breeding and seed production department of the Institute of Bast Crops of the NAAS of Ukraine (Glukhiv, 2014–2019). The content of neutral substances [cannabinol (CBN), cannabidiol (CBD), tetrahydrocannabinol (THC)] and acids (CBDA, THCA) was determined by using a thin layer chromatography (TLC) and gas-liquid chromatography (GLC) methods. For the study, 11 monoecious varieties of C. sativa: ‘YuSO 1’, ‘YuSO 31’, ‘Hliana’, ‘Viktoriia’, ‘Hlesiia’, ‘Hlukhivskyi 46’, ‘Hlukhivski 51’, ‘Zoloto­niski 15’ and 3 introduced varieties: ‘Fedora 17’, ‘Felina 32’, ‘Futura 77’ (France) which differed among themselves in morphological, biological, genetic, ecological-geographical and economically valuable characteristics were selected. Results. Biological and morphological characteristics of modern monoecious varieties of C. sativa were investigated depending on the ecological and geographical zones of origin, conditions of the growing season and the stage of ontogenesis. The functional interdependence between the formation of specialized excretory structures and the content of cannabinoid substances in plants of different varieties of C. sa­tiva was revealed. The following promising varieties of C. sativa in a ration of ((THC + CBN) ≤ CBD) point the possibility to use them as the source material for creating the medicinal varie­ties of plants with a high content of CBD. Conclusions. Nowadays C. sativa is the main source of phyto material for industrial production of natural CBD. In recent years, high-yielding varieties of C. sativa have been created, which, together with high commercially valuable traits, did not contain psychoactive THC and had an insignificant amount of CBD. The results of the research indicated the features of the seasonal growth rhythm, development of the plants and the morphological and biological features of modern monoecious introduced and domestic varieties of C. sativa in the North-east region of Ukraine. The low correlation between the content of cannabinoid substances and their acids in varieties, which are cha­racterized by the low content of cannabinoid compounds was established. According to the developed own classification (THC + KBN): CBD, varieties with a predominant CBD content ‘Hlukhivskyi 46’, ‘Zolotoniski 15’, ‘Hliana’ which are of significant medicinal value were identified.

Purpose. To study biological characteristics of growth and development of middle-early soybean varieties and create a model of phenotype productivity. Methods. Special and gene­ral techniques for studies. Results. Optimal productivity of plants is forming merely at the expense of efficient ratio of all the elements of their structure. It often happens that in case of underdevelopment of one of the structure components yield to some extent can be offset by better development of other elements. Eight indicators were defined which make the largest contribution to the productivity trait of a variety: seed weight per plant, total number of branches, number of nodes per plant, number of pods per plant, number of seeds per plant, number of flowers, plant height, 1000 kernel weight. The first four indicators provided most of the total contribution to a trait of seed weight per plant. Model building was based on hierarchy of productivity traits display in ontogenesis and compliance of their development in organogenesis. The model consists of two modules of traits – resulting and some componental showing phenotypic realization of the genetic formula. It was found that the plant height significantly influence the number of nodes per plant (r = 0,76), and the number of pods per plant (r = 0,43) depends on this trait. In addition, correlation based on the research was obtained between the number of flowers per plant and plant height (r = 0,35), and number of nodes (r = 0,76). It was established that the number of flowers per plant determines the development of pods on the plant so it is quite strongly correlated with this trait (r = 0,99). Conclusions. It was determined that the number of pods per plant and the number of seeds per plant have a very strong correlation (r = 0,96). Besides, such trait as the number of seeds per plant has a strong relationship with the seed weight per plant (r = 0,79).

Purpose. To study the dynamics of soft winter wheat lectin activity in caryopsis and at the early stages of ontogenesis of varieties developed by Poltava State Agrarian Academy as well as investigate varietal differences depending on dynamic pH medium. Methods. Laboratory analysis, method of hema­gglutination reaction, analytical approach, statistical evaluation. Results. A change in lectin activity was determined in samples of 14 soft winter wheat varieties in caryopsis and at the early stages of ontogenesis (on the third, seventh, tenth and twelfth day of seedlings emergence). High lectin activity was observed in samples of seven and ten days seedlings. This could be evidence of active participation of proteins in physio­logical and biochemical processes at the time of emerging wheat tillering node that can be important in forming adaptive reactions to stress. Wheat lectin activity variation for рН ranging between 4,0 and 8,0 that depended on a variety was defined for the first time. Conclusions. According to hema­gglutination ability of wheat lectins, all varieties were divided into three groups: of high ability – 4 varieties, middle – 9 varieties, low – 1 variety. Varietal variability for the investigated trait can be used in breeding programs as marker trait. In most varieties variation of hemagglutination was observed at dilutions ranging between 1:2 and 1:256. Availability of two lectin agglutination peaks in acidic and alkaline media for seedlings was fixed.

Purpose. Assessing stability of yield formation of complex-valued varieties and lines of spring triticale under conditions and of different years of their growing. Identifying the best genotypes for yield potential, plasticity and stability. Methods. Ontogenetic, statistical and mathematical analyses. Results. Adaptive capacity and breeding value of spring triticale varieties and lines was established. Methods of breeding and parentage of the best samples were analyzed. Comparison of yields under conditions in of different years of growing allowed to identify genotypes with high yield potential – ‘ЯТХ 38-14’, ‘ЯТХ 61-14’, ‘ЯТХ 62-14’, with stable yields – ‘ЯТХ 17-14’, ‘Boryviter kharkivskyi’, ‘ЯТХ 43-14’, ‘Gusar kharkivskyi’, drought resistance ones – ‘ЯТХ 37-14’, ‘ЯТХ 43-14’, ‘ЯТХ-64-14’. The genotypes ‘Lebіd kharkіvskyi’, ‘ЯТХ 38-14’, ‘ЯТХ 62-14’ appeared to be more plastic. These samples may be used of hybridization to improve yield. Conclusions. The most promising to production and breeding are the lines ‘ЯТХ 17-14’, ‘ЯТХ 64-14’, ‘ЯТХ 37-14’, ‘ЯТХ 43-14’ (their average yield 4,27–4,48 t/ha) and varieties ‘Zlit kharkivskyi’, ‘Boryviter kharkivskyi’, ‘Gusar kharkivskyi’, ‘Darkhliba kharkivskyi’, which have high adaptive capacity combined with high productivity. They are valuable for use as a starting material in breeding for adaptability.