STUDY ON "IN VITRO" MICROTUBERIZATION OF POTATO (SOLANUM TUBEROSUM L.) GENOTYPES DERIVED FROM TRUE POTATO SEED

Abstract

Within this study a protocol was developed to obtain "in vitro" microtubers starting from botanical potato seed. The study was carried out between June and September 2023, in the Research Laboratory for Plant Tissue Cultures belonging to National Institute of Research and Development for Potato and Sugar Beet (NIRDPSB) Brasov. For the initiation of microtuberization, it was started from healthy (virus-free) potato plantlets, used as a source of uninodal explants. Fragments approximately 1.5 cm in size, containing a node, associated leaf and portions of neighboring internodes, were inoculated on Murashige-Skoog culture medium supplemented with sucrose, growth regulators and agar, specific to each stage of the microtuberization process. 15 explants were inoculated in each culture vessel, which were subsequently incubated in the climatic chamber, at a temperature of 20±2 °C, a photoperiod of 16 hours of light and 8 hours of darkness, for 4 weeks. When the potato microplants have reached a height of about 7-8 cm, the tuberization medium, liquid (100 ml/jar) is added to the culture vessels and then the cultures are incubated in the growth chamber, at 17±2 °C, in the dark, for a period of 3 months (permanent immersion method). Under these conditions, after about 120 days potato microtubers were formed and evaluated in terms of number, weight and calibration classes. The biological material tested for microtuberization capacity was represented by 2 potato genotypes derived from true seed (GIL 19-03-07, GIL 19-03-29) and 3 potato varieties created at NIRDPSB Brasov (Ervant, Castrum, Marvis ). The best results in terms of average weight/jar of potato microtubers (10.89 g), percentage of microtubers > 10 mm (23%) and rate of microtubers in the calibration class 7-10 mm (41%) were recorded at the genotype GIL 19-03-29. The highest values in terms of the average number of microtubers/jar (26.8) was recorded at the genotype GIL 19-03-07.

Keywords

• potato, plant tissue culture, true potato seed, microtuberization, permanent immersion