Our experiment was conducted in two stages, i.e., pretreatment (first stage) and regeneration (second stage). The first stage was carried out in a liquid Murashige and Skoog basal medium (5 µM BAP and 0.05 µM NAA) in a bioreactor with a RITA temporary immersion system under the light of a fluorescent lamp. Explants (bulbscales) were immersed in the medium once a day for 15 minutes (RITA 1×15) or three times a day for 1 (RITA 3×1), 5 (RITA 3×5), and 15 minutes (RITA 3×15) for one to six weeks. For regeneration, the explants were transferred onto a solid medium of the same composition for another six weeks. The bulbscales not exposed to the liquid medium were used as a control. Biomass weight, biomass growth index, number and percentage of dry matter of bulblets, and the content of soluble sugars in the bulblets and in the liquid medium were examined. The bulblets were formed in all combinations from the third week of the culture, and their number increased in the RITA 3×15 combination for both the first and the second stages of the experiment. After the longest, 6-week pretreatment, more bulblets were obtained than in the control. Their fresh weight after six weeks of regeneration was positively associated with extended pretreatment time. This was in contrast with the dry weight of the bulblets, which decreased in the second stage of the experiment along with the extension of its first stage. Prolonged contact of the explants with the liquid medium during the pretreatment resulted in a higher content of soluble sugars in the bulblets at both stages of the experiment. The content of soluble sugars in the liquid medium decreased over time in all tested combinations. After six weeks of bioreactor culture, the lowest level of soluble sugars was observed in the RITA 3×15 combination.