Establishment of an Efficient In Vitro Propagation Protocol for Cannabis sativa L. subsp. ruderalis Janish

Cannabis sativa L., subsp. ruderalis Janish., 'Finola' is a dioecious cultivar of Finnish origin. This cultivar is very interesting because its cultivation cycle lasts less than 3 months. The aim of this study was to define an efficient micropropagation protocol to ensure in vitro multiplication and rooting and in vivo acclimatization. Two different explant sources were tested: seed-derived in vitro explants and nodal segments containing axillary buds from selected mother plants. Shoot proliferation was tested on different growth media enriched with cytokinin alone or cytokinin in combination with auxins. Among all combinations, the best results were obtained by combining the Basal Medium (BM-a Murashige and Skoog modified medium) with sucrose (20 g L-1), thidiazuron (TDZ 0.4 mg L-1), and 1-naphthalenacetic acid (NAA 0.2 mg L-1). Regarding rooting induction, the plants developed an extensive root system under red/blue lights on BM enriched with sucrose (30 g L-1) and indol-3 butyric acid (0.1 mg L-1), which allowed the survival of more than 90 percent of the plantlets once transplanted into the climate-controlled greenhouse.