Abstract
Y. Fedoruk*, M. Grabovskyi, L. Pravdyva, N. Ostrenko, T. Lozinska, N. Fedoruk, T. Grabovska, S. Obrazhyy, S. Hornovska and N. Prisjazhnjuk
Potato, one of the most important food crops in the world, is susceptible to viruses, which reduce its yield and production efficiency. The resistance of potatoes to viral infection is an essential factor in the preservation of the variety’s productive qualities. In addition, there are several ways of selection for recovering and obtaining the initial seed material that is free from viruses for further reproduction in the seed growing of potatoes. It should be noted that in the literature the issues of medium-late potato varieties resistance to viral diseases in the Forest-Steppe zone of Ukraine are not fully covered, which has become the subject of our research. In our studies we used the material obtained by the method of improving selections, as well as using thermotherapy and apical meristem culture. Over the years of reproduction both meristematic and seed material from improving selections, the virus infestation in plants wasn’t changed significantly, provided that all seed growing events were observed. It has been proven that the yield of super-super-elite of Lybid variety is not significantly changed depending on the method of obtaining the initial material. The variety Gorlitsa has higher yield in the plantations formed by clonal propagation. It has been established that the yield of variety Lybid super-elite varies, but not significantly, depending on the method of obtaining the initial material. The variety Gorlitsa has a higher super-elite yield when using the initial material from clonal propagation in breeding nurseries with use of improved selections. Significant influence on the manifestation of the sign, both in the cultivation of super-super-elites and super-elites, has the weather conditions of the year and the biological characteristics of the variety. In 2017, the highest yield of tubers was obtained at Gorlitsa – 3.74·104 kg ha-1, at Lybid the lower yield was 2.43·104 kg ha-1. In 2018, the highest yield of tubers was formed by Lybid variety – 3.50·104 kg ha-1, and the lowest was byt Gorlitsa variety – 2.56·104 kg ha-1.