Influence of Additives on Enhanced In vitro Shoot Multiplication of Orthosiphon aristatus (Blume) Miq

Orthosiphon aristatus is a valuable medicinal plant and different parts of the plant are pharmaceutically used for the treatment of various diseases. The present study was designed to develop an efficient protocol for micropropagation of O. aristatus from nodal explants and to study the influence of additives on the enhancement of the number of shoots per explant. Among the different types of additives used, 10% coconut water and 30 mg/L glutamine added to Murashige and Skoog’s (MS) medium supplemented with 1.0 mg/L 6-benzyl amino purine (BAP) and 0.5 mg/L kinetin (KIN) was found to be most effective. Maximum number of shoots (44.07 ± 0.38) with 100% shooting response and shoot length of 7.47 ± 0.10 cm was recorded. In vitro rooting of the microshoots was achieved on half-strength MS medium containing 0.5 mg/L indole-3-butyric acid (IBA), producing an average of 30.27 ± 0.36 roots and 6.02 ± 0.20 cm root length. The rooted shoots were acclimatized with 100% survival rate on coco pith: soil (3:1) planting substrate and was successfully transferred to field conditions. The hardened plants exhibited homogeneity and no morphological variations were observed among the regenerants and the mother plants. Thus, the procedure described is a quick and reliable method which could be applied for efficient large-scale propagation, genetic transformation assays and secondary metabolite production.