In Vitro Propagation of the Endangered <i>Kosteletzkya pentacarpos</i> (L.) Ledeb: Conservation Applications and Horticultural Prospects

Employing rare or threatened species in ornamental horticulture offers a dual benefit by promoting climate adaptation and enhancing species conservation. <i>Kosteletzkya pentacarpos</i>, an endangered halophytic species, holds potential for introduction into the nursery industry, but efficient propagation methods are lacking. The present study investigated the in vitro propagation of the species using nodal explants excised from aseptic seedlings. A two-stage in vitro culture system was tested with thidiazuron (TDZ) promoting shoot initiation at low concentrations, while higher levels induced callus formation. Transferring micro-shoots to hormone free-, Murashige and Skoog medium (MS) promoted the highest shoot multiplication and elongation. The effect of sodium chloride (NaCl) on in vitro culture was also assessed, with MS media containing up to 5.0 g L⁻¹ NaCl supporting successful culture establishment. Spontaneous rooting was observed during various stages of the culture process. Micro-shoots were rooted at 100.0% on half strength MS medium with or without indole-3-butyric acid, and all plantlets were successfully acclimatized in a peat–perlite substrate (1/1, <i>v</i>/<i>v</i>). Thus, the present protocol provides an efficient system for the large-scale propagation of <i>K. pentacarpos</i> serving as a valuable tool for its conservation and the potential use in the nursery industry.