*3.4. Rooting of Microshoots and Acclimation*

For rooting, the individually harvested shootlets were transferred to MS basal medium containing an auxin such as IAA at concentration of 0, 0.25, 0.5, 1.0, and 2.0 μM (Table 5). Adding IBA to the basal medium was found to be effective for root induction from in vitro regenerated shootlets of *P. amboinicus* (Figure 1D). On medium containing 0.5 IBA, the shootlets responded best, yielding 5.3 roots/shootlets and with a root induction frequency of 93.7% in 4 weeks. For acclimatization, the individual plantlets with a complete root system were removed from semi-solid agar rooting media, shifted to pots containing sterile planting materials, and grown for weeks inside a growth chamber. After four weeks, the surviving pants were moved to field condition. Out of 50 in vitro-produced plantlets, 47 survived, resulting in a survival rate of 94 percent with no phenotypic changes between the plants.

**Table 5.** Effect of IBA on in vitro root induction from microshoots of *Plectranthus amboinicus*.


Data are expressed as mean ± SE recorded after 4 weeks of culture on shoot induction medium. Tukey's honestly significant difference test (Tukey's HSD) analysis was performed for comparisons of significant differences between treatments at a *p*-value of less than 0.05.
