Object of study – in vitro culture, adaptive potential of potato varieties for cultivation with double-crop culture in the south of Ukraine on irrigation condition. Aim – determine the optimal factors of influence on the induction of tuberization rate of potato plants in vitro and to assess the adaptive and productive potentials of new promising varieties of various groups of ripeness with double-crop culture in the south of Ukraine. Methods – general scientific methods - analysis, synthesis, modeling. Special - field (assessment of the similarity of potatoes, determination of biometric indicators and elements of the formation of agrocenosis, yield of tubers and crop seeds, adaptive ability of varieties of different maturity) laboratory (biochemical analysis of tubers) comparative-calculation (determination of economic efficiency); biotechnological (in the process of creating the source material) statistical (assessment of the reliability of the obtained experimental data, determination of correlations). Results – the optimal composition of the nutritious environment and the tier of grafting the varieties of different ripening groups have been determined, which is expected to guarantee the provision of the maximum reproduction rate and high intensity of plant tuber formation in vitro. The most suitable for double-cropping potato varieties are early-ripening Tiras, Slauta and Factor, which provide a yield of 38.68–43.17 t/ha per season; the middle-early variety Levada (38.47 t/ha) and middle-ripening – Slovyanka and Anika with a seasonal yield of 36.48-40.24 t/ha. To obtain early potato production at the level of 18-24 t/ha and 22-26 t/ha of biologically ripe potatoes under irrigation conditions in the south of Ukraine, early varieties Tiras, Slauta, Factor, medium-early variety Levada, mid-season Slovyanka, Miroslava, Knyaginya, Anika should be used. Novelty – for the first time, the peculiarities of the processes of growth, development, induction of tuberization rate and breeding coefficient of plants in vitro of varieties of different groups of ripeness were established with the integrated use of nutrient media of different composition and tier of grafting; the optimal ratio of the studied factors has been established, which guarantees the maximum productivity of plants in vitro while reducing the use of material resources. Regularities have been established and mathematical models have been developed for the correlation-regression dependence of the induction of tuberization rate of potato plants in in vitro culture, depending on the cultivation methods and genetic characteristics of varieties. For the first time in the conditions of the south of Ukraine, the influence of climatic factors of cultivation on the characteristics of growth and development, adaptive potential, the yield of conditioned seeds and the formation of economically valuable traits of new potato varieties for further use in the breeding process in order to create varieties suitable for cultivation with a double-crop culture under irrigation conditions was determined. A method has been developed for assessing and selecting potato varieties to improve the accuracy of identification for their suitability for cultivation with a double-crop culture. The scientific value – the process of reproduction of the healthy original seed material of potato varieties of different ripeness groups in in vitro culture has been improved. Methods for obtaining microtubers of potato varieties in vitro of various groups of ripeness and optimization of the process of microclonal reproduction, depending on the conditions of plant cultivation in vitro, were further developed; methods of assessing and selecting potato varieties for suitability for double-crop culture. Theoretical and practical results of scientific research made it possible to develop patents for a useful model and scientific and practical recommendations for the assessment and selection of potato varieties for suitability for cultivation behind a double-crop culture under irrigation conditions in the south of Ukraine. Sector – agriculture, biotechnology.
