Primary morphogenesis of Sorbus Torminalis L. (Grantz) into in vitro culture

Abstract

Nowadays in vitro methods, combined with ex situ and becoming an increasingly important means of preserving and maintaining the level of phytodiversity stability. Sorbus torminalis L. is a tree of the Rosaceae family, which grows on the territory of Ukraine, belongs to rare, valuable aboriginal species and is listed in the Red Book of Ukraine, with its protection status - endangered. The peculiarities of introduction of in vitro culture of perennial representatives of S. torminalis with the use of different types of explants, sterilizing substances, cultivation conditions and nutrient medium composition are presented in the paper. For in vitro culture of S. torminalis, annual shoots with apical and lateral buds 15-25 cm long are optimal. The influence of different sterilization options on the development of primary microshoots has been studied. For sterilization of artificially awakened and young shoots it is most effective to use 0.1% solution of AgNO3 (7 min) and 15% solution of H2O2 (10 min). The developed method of sterilization of S. torminalis explants provided 80-90% yield of aseptic plant material. It was found that the sterilization regime did not significantly affect the primary morphogenesis of explants and was uniform. The optimal components of nutrient media at the stage of introduction into vitro culture and primary morphogenesis of S. torminalis have been established. For the cultivation of different types of explants of S. torminalis, used WPM nutrient media with the addition of synthetic plant growth regulators 6-benzylaminopurine, thidiazuron, kinetin 0,5-1,5 mg mg∙l-1 and α-naphthylacetic acid 0,01-0,05 mg∙l-1 both alone and in combination with each other. In particular, for the regeneration of plants from the lateral and apical buds of explants is effective WPM medium with the addition of BAP 1,5 mg∙l-1 + 0,5 mg∙l-1 NAA and WPM + TDZ medium 0,5 mg∙l-1 with adding PVP 200 mg∙l-1. To induce the laying of additional buds and shoots on the explant from the apical meristems in the medium should be added 4,0 mg∙l-1 BAP + 0,01 mg∙l-1 NAA with the addition of PVP 200 mg∙l-1.