MICROPROPAGATION OF POTATO SEED TUBERS (Solanum tuberosum L.) UNDER IN VITRO CONDITIONS

In this paper the results of influence of phytohormone gibberellic acid GA 3 on sprout formation in in vivo conditions and in vitro microtuberization of the potato varieties Agria, Agata, Sunshine, Ultra and Marabel are presented. The tubers from all varieties utilized in the experiment were certified potato seed tuber material. The experiment in in vitro conditions was established on sprout explants and nodal segment explants on the MS medium (Murashige & Skoog, 1962) with addition of different combination and concentration of auxins and cytokines. Microtuberization was stimulated by rising the concentration of sucrose in MS medium from 40g/l to 60 g/l and 80g/l, respectively. The in vivo tuber treatment with 30mg/l GA 3 was the most effective treatment for all potato varieties in proliferation of sprouts. All tubers that were treated with GA 3 resulted in de novo sprouting of tubers. The variety Agata resulted with 100% of microtuberization from nodal segment explants on MS medium supplied with 40g/l and 80g/l sucrose. Microtuberization of the variety Sunshine was stimulated with addition of 80 g/l sucrose in MS medium. The developed microtubers were detached from the nodal segments and subcultured on new MS medium supplied with BAP 4mg/l, KIN 4mg/l and 8% of sucrose to increase their weight.