THE IN VITRO REGENERATIVE CAPACITY OF THE POTATO CULTIVARS Ostara, Desirée AND Eba MERISTEM

The meristem of three cultivars of Solanum tuberosum L., Ostara, Desirée and Eba was cultivated in vitro in order to observe the regeneration capacity and the organogenetic evolution of the tissues on various culture media. Meristems of 0.1-0.2 mm were prelevated from forced tubers; they were then inoculated on the different medium variants. (Table 1) The regeneration percentage for the in vitro meristem varied with the cultivar: 80 - 95% for Ostara, 70 – 80% for Desirée and 50 – 67% for Eba, as compared to 18 – 20% for the control medium (without hormones).The best variants proved to be M7 and M8 with all the cultivars, the regeneration percentage being the highest: Ostara 95%, Desirée 85% and Eba 67%. The in vitro organogenesis (number of stems, their height, number of roots and their length) was visible on all variants, according to the hormonal balance. The variants containing zeatine and 2-isopentenyl adenine (M5, M6, M7 şi M8) provided the best results. The Desiree had a special evolution, with about 45 neoplantlets /explant and almost double values in comparison with the other cultivars