Axillary shoots: Initiation to acclimatization on micropropagation of Philodendron ‘Super Atom’

Philodendron ‘Super Atom’ is among Indonesia's most favoured ornamental foliage plants, yet traditional propagation methods pose challenges. Establishing an in vitro propagation protocol for this plant was crucial to sustainably produce high-quality planting materials to meet consumer demand. All experiments were conducted using a completely randomized design (CRD) with four replicates. High axillary shoots with regeneration issues were used as explant sources, initiated on Murashige and Skoog (MS) medium containing 1 mg L-1 thidiazuron (TDZ) and 3 mg L-1 N6-benzylaminopurine (BAP). A total of 4.8 shoots per explant were regenerated on MS medium supplemented with 0.3 mg L-1 BAP and 0.005 mg L-1 IAA. A slight enhancement in axillary shoot proliferation was noted on MS medium with 0.5 mg L-1 BAP, 0.5 mg L-1 TDZ, and 0.025 mg L-1 α-naphthalene acetic acid (NAA), yielding 6.7 shoots explant-1, and 0.2 mg L-1 BAP and 0.01 mg L-1 indole-3-butyric acid (IBA), yielding 6.9 shoots explant-1. A significant improvement was achieved on MS medium fortified with 0.2 mg L-1 BAP and 0.005 mg L-1 indole-3-acetic acid (IAA), resulting in 13.6 shoots explant-1. Rooted shoots were readily observed in the proliferation medium. A 100% survival rate of plantlets was successfully acclimatized using a mixture of burned rice husks, hyacinth organic manure, and cocopeat (1:2:1, v/v/v), as well as burned rice husks and hyacinth organic manure (1:1, v/v). The findings of this study can serve as a model for developing and establishing new in vitro mass propagation protocols for other Philodendron species with appropriate modifications.