Regeneration of Pogostemon cablin Benth. ‘Sidikalang’ through Indirect Organogenesis and Shoot Multiplication for Production of True-to-Type Plant

Abstract

Patchouli Pogostemon cablin Benth. ‘Sidikalang’ (Acehnese Patchouli) is a member of the Lamiaceae, mint family. Aromatic oil known as patchouli oil can be produced from its leaves, which is highly valued in the perfumery and aromatherapy industry, because of its aromatic spicy fragrance. Patchouli oil also has various phytocompounds that have therapeutic effects including antimicrobial, antidepressant, antiinflammatory, and antioxidant. This study aims to establish an efficient and reproducible protocol for indirect regeneration from leaf explants and multiple shoots from nodal explants. Indirect organogenesis was done using solid medium of MS (Murashige-Skoog) with some treatments, such as 0.5 mg/L NAA + 0.1 mg/L BAP, 1 mg/L NAA + 0.1 mg/L BAP, and 1.5 mg/L NAA + 0.1 mg/L BAP, whereas multiple shoots from nodal explants were cultured on MS medium with various concentration of BAP, such as 0.5 mg/L, 1.0 mg/L, and 1.5 mg/L. Then, for the rooting stage from shoots, the shoots were cultured on halfstrength MS medium without Plant Growth Regulator (PGR) and MS medium with some treatment, such as without PGR, 0.5 mg/L IBA, and 0.5 mg/L NAA, respectively. Furthermore, the plantlets derived from the in vitro rooting stage treatment were acclimatized onto a combination of soil: compost (1:1). In addition, in vitro shoots were also planted directly as micro-shoot cuttings on combination soil: compost (1:1 ratio). The optimum treatment for indirect organogenesis was on MS medium supplemented with 1 mg/L NAA + ¬0.1 mg/L BAP. For multiple shoots from nodal explant, MS medium supplemented with 0.5 mg/L BAP was the optimum medium. Shoots were cultured in a half-strength MS medium for the rooting stage and grew to form plantlets with normal root morphology. Overall, patchouli plantlets were obtained more quickly by directly planting micro-shoot cuttings in ex vitro conditions rather than going through the in vitro rooting stage.