EN
The effects of different combinations of plant growth regulators (PGRs) on callus induction and plant regeneration were investigated in five cultivars of Cannabis sativa L. Callus was induced from different explant sources (young leaves, petioles, internodes, axillary buds) on MS basal medium with various concentrations of PGRs (2,4-D, DICAMBA, KIN, NAA). The highest frequency of callus induction (avg. 82.7% of eight medium combinations) was exhibited by petiole explants of cv. Fibrimon-24. Plant regeneration was obtained from all studied cultivars. The highest number of plants was regenerated from callus tissue of petiole explants on MS medium containing DICAMBA. A total of 46 plants (1.35% of callus) were regenerated: 16 (0.47%) from cv. Silesia petioles, 7 (0.20%) from cv. Novosadska petioles, 6 (0.18%) from cv. Fedrina-74 petioles, 12 (0.35%) from cv. Fibrimon-24 axillary buds, and 5 (0.15%) from cv. Juso 15 internodes. Significant improvement of hemp plant regeneration in vitro was achieved.