IN VITRO CULTURE AND MICROPROPAGATION OF CARALLUMA STALAGMIFERA – AN ENDEMIC MEDICINAL PLANT

An efficient in vitro regeneration protocol was developed for Carallumastalagmifera, an endemic and medicinally important plant of the family Apocynaceae. Nodal and apical shoot tip explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of 2,4-D, BAP, and combinations with auxins (NAA and IAA). Callus induction was achieved from nodal explants, with the maximum response (80%) and high-quality callus (+++) observed at 1.5 mg/l 2,4-D. Direct shoot regeneration was recorded from both nodal and apical explants, with apical shoot tips showing superior response (60%) at 2.0 mg/l BAP, producing four shoots per explant. The combination of BAP (2.0 mg/l) with NAA (1.0 mg/l) or IAA (1.0 mg/l) further enhanced multiple shoot induction, yielding up to 18 shoots in subcultures. Rooting was optimized on ½ MS medium supplemented with 2.0 mg/l IBA, producing 70% response with thick and healthy roots, while NAA supported fewer but longer roots (55% at 1.0 mg/l). Hardened plantlets established successfully under greenhouse and field conditions. This protocol provides a reliable system for the conservation, large-scale propagation, and sustainable utilization of C. stalagmifera.