Micropropagation Protocol and Genetic Stability of the Salix myrtilloides Plants Cultivated In Vitro

Salix myrtilloides L. is a relict species, threatened with extinction in many European countries. To prevent the loss of the species, tissue culture was established to produce plant material for reintroduction in natural habitats. Micropropagation was chosen as a method to obtain new plants. S. myrtilloides shoots were disinfected with NaOCl, AgNO₃, or with a two-step disinfection with NaOCl, and then placed on MS medium supplemented with BA at 1 mg·dm^-3 and IBA at 0.1 mg·dm^-3. Regenerated shoots were cultivated in presence of BA, KIN, and 2iP to select the treatment with the highest multiplication rate. The obtained plants were acclimatized to ex vitro conditions. Inter-simple sequence repeat (ISSR) and flow cytometric analyses were conducted on in vitro regenerated plants to check their genetic stability. The best disinfection results were obtained when explants were treated with 1.5% NaOCl for 20 min. The highest multiplication rate and good quality plants were noted in the control media, without growth regualtors and in presence of kinetin at 0.5 mg·dm^-3. Flow cytometry and ISSR analyses confirmed genetic stability in plantlets, which indicated the possibility to use the in vitro obtained plants for reintroduction.