The results of the study are devoted to the important problem of potatoesthe attachment of large numbers of tubers to plants. Therefore, the purpose of the experiment was to determine the effect of the crossing components on the expression of the index among the off spring of original material created with the participation of Mexican wild potato species. The studies were performed according to the methods adopted for breeding and genetic experiments with potatoes. The highest number of tubers (up to 12 pieces/nest) was characterized by the six-species hybrid 81.459s18, three-time backcross of the six-species hybrid 08.195/73, as well as the variety of intra-species origin of Podolia. The mean of the parents on manifestation of the trait depended on its expression in the crossing components and the maximum was 13.6 tubers/nest in the crossing components of the hybrid 08.195/73 and the Partner variety. The offspring of the combinations differed significantly in the limits of manifestation of the trait. It is established that its minimum value is due to the use of the maternal form of the Verdi variety. The opposite was true of the descendants of the crosses of Bagryanа x 89.202s79. Depending on the other component of the crossing, a specific reaction of the Podolia variety to the maximum number of tubers in the nest was detected. Selected populations with an average manifestation of a trait among offspring of more than 10 tubers/nest, which exceeded the expression of the standard varieties by 2 or more times. Successful in this respect were combinations of 10.6G38 x Podolia, Basis x Podolia, Bagryanа x 89.202s79 and Teteriv x Streams. The opposite was true for populations of Verdi x Basis and Stream x Podolia. A high or very close correlation was established between the mean population value of the indicator and, in part, offspring with a higher expression of the trait than in the better parental form; the average offspring and the proportion of hybrids with the number of tubers in the nest 10 pcs. and larger, and with more of them than in the best parent form.

к.с.-г.н., доцент, доцент кафедри біотехнології та фітофармакології, Сумський національний аграрний університет Гордієнко В.В. -к.с.-г.н., с.н.с., завідувачка лабораторії, Інститут картоплярства Національної академії аграрних наук Подгаєцький А.А. -д.с.-г.н., професор, завідувач кафедри біотехнології та фітофармакології, Сумський національний аграрний університет Гнітецький М.О. -асистент кафедри біотехнології та фітофармакології, Сумський національний аграрний університет 47 Землеробство, рослинництво, овочівництво та баштанництво Близькі дані до згаданих вище отримані під час порівняння гібридів 08.187/13 і 08.187/93, за винятком того, що потенціал першого з них значно вищий, ніж в останнього: 1256 г/гніздо проти 743 г/гніздо. Це також відбилось на величині коефіцієнта варіації. Ключові слова: картопля, міжвидові гібриди, їх беккроси, продуктивність, місця і роки випробування. Realization of the productivity of complex specified potato hybrids, their backcrosses, depending on external conditionsThe article presents the results of a study to determine the impact on the performance of potato samples of external conditions. The influence of two test sites, meteorological conditions during the growing season of potatoes in 2015-2017 on the maximum productivity, the manifestation of more than 1000 g / the bush, the proportion of interspecific hybrids, their backcrosses, which had a higher expression of the index than the best variety standard. The latter manifested itself in 2015 and 2017 in Sumy NAU within the limits of 3.9-11.8%, and in the same period in the Institute of Potato in 2015 (0.5%) and 2016 (4.4%).The specificity of the mutual influence of test sites and meteorological conditions in the years of their conducting on the distribution of the studied hybrids by productivity is proved. Modal classes in 2015 and 2016 in SNAU were with the minimum class index -300 g / the bush and less, which, respectively, was 55.9 and 47.1%. The opposite was true in 2017, when the highest proportion of hybrids (44.1%) had a productivity of more than 800 g / the bush. At the same time, with the exception of the last class in 2016, there were others in the sample.Something else concerned the conditions of the Potato Institute. In the two years, however, the others -2015 and 2017, the modal class turned out to be 300 g / the bush and less. Only in 2016, the modal class had a value within the range of 601-700 g / the bush. In addition, in four classes, starting at 501-600 g / the bush and no longer distinguished hybrids in 2015 and 2017.The peculiarities of the manifestation of performance among the nursing forms are proved, which manifested in the difference between the variants depending on the influence of the environment.