Abstract
The present investigation was carried out to conserve the species of an endangered and valuable medicinal forest tree Oroxylum indicum (L) Kurz through in vitro culture technology using cotyleonary node, nodal and shoot tip explants. All these explants were cultured on MS (Murashige & Skoog’s) medium supplemented with different concentrations of plant growth regulators(PGRs) viz., BAP/Kn (1.0-7.0 mg/L)/TDZ (0.2-1.0 mg/L) individually. Among the cytokinins used, 5.0 mg/L BAP showed the maximum percentage of response and more number of multiple shoots (15.0±0.10) formation per nodal explant followed by shoot tip explants (12.0±1.08) at 3.0 mg/L BAP. The in vitro developed micro-shoots were elongated on MS+0.5 mg/L GA3. These elongated micro-shoots were cultured on ½ strength MS medium augmented with IAA/IBA/NAA for in vitro rooting. Maximum percentage (86%) of rhizogenesis with profuse rooting (10±0.68) was observed at 1.0 mg/L IBA. These in vitro rooted plantlets were acclimatized and successfully transferred into field. The survival of the percentage of in vitro regenerated plants was observed as 59%. The regenerated plants were found to be similar to donor plant. Our present investigation reports that the response of nodal explants on MS+5.0 mg/L BAP followed by shoot tip explants at 3.0 mg/L found to be the best explants and hormonal concentrations respectively for multiplication and conservation of medicinally important an endangered forest tree O. indicum.
