Peculiarities of morphogenesis of the endangered species of wilow (Salix spp.) in vitro

Conservation and reproduction of rare genotypes of Salix L. species, in particular the blunt-leaved willow (Salix retusa L.) and Jacquin’s Willow (Salix alpina Scop.) that are listed in the Red Data Book of Ukraine in the status of rare and endangered species, is one of the urgent tasks of the present. The aim of research was to develop methods of introduction of S. retusa and S. alpina into in vitro culture for their mass reproduction and conservation. The plant material was cultivated on a culture medium prescribed by MS, WPM, and DKW with the addition of growth regulators according to the conventional method. Effective sterilization (over 80%) of explants of S. retusa and S. alpina was achieved by applying a stepwise method, which consisted of consistently maintaining them in solutions 0.1% HgCl2 and 1.0% AgNO3 for 5–6 min. Significant results in the regeneration of explants by activating the growth of available meristems in vitro were observed on MS with the addition of 0.25–0.5 mg/l 6-(Furfurylaminopurine, kinetin) and 2 g/l activated carbon. Our further research will serve as a base for developing microclonal propagation of S. retusa and S. alpina for their conservation and reproduction in vitro.