In Vitro Culture Establishment and Micropropagation of Daphne altaica Pall., a Rare Medicinal Species of Kazakhstan

Daphne altaica Pall. is a rare medicinal shrub of Kazakhstan with poor natural regeneration and no reported in vitro propagation protocol. We established in vitro cultures from nodal explants of wild plants and evaluated the effects of collection season, basal medium, and cytokinin type. Spring-collected explants outperformed autumn-collected explants at every stage. Disinfection with 0.1% HgCl2 for 5 min gave 8.61% contamination and 61.65% explant viability in spring material (12.52% and 34.22% in autumn material). On Woody Plant Medium (WPM) with 1.0 mg L−1 6-benzylaminopurine and 0.1 mg L−1 1-naphthaleneacetic acid (NAA), axillary shoots emerged after 3.3 (spring) and 10.3 days (autumn), with induction rates of 100% and 77.78%. Shoot proliferation was highest on WPM with 1.0 mg L−1 meta-topolin and 0.1 mg L−1 NAA (5.97 and 3.11 shoots per explant in spring and autumn material); basal medium, cytokinin, and season all had significant effects (p < 0.001). Rooting remained the main bottleneck (maximum 20.63% on WPM with 2 mg L−1 indole-3-butyric acid), and ex vitro acclimatization was not assessed. These results provide the first baseline conditions for the in vitro establishment and multiplication of D. altaica.