Micropropagation of <i>Philodendron</i> ‘White Knight’ via Shoot Regeneration from Petiole Explants

<i>Philodendron</i> ‘White Knight’ is a popular climbing evergreen plant typically propagated through stem cuttings. However, this method is slow and inefficient, making it challenging to meet the rising market demand. In vitro propagation could enhance the multiplication of this cultivar. However, research on its in vitro propagation is limited. Therefore, the objective of the present study was to establish an efficient micropropagation technique to mass-produce <i>Philodendron</i> ‘White Knight’ to meet the market demand. We investigate the impact of silver nanoparticles (Ag NPs) on the surface sterilization of <i>Philodendron</i> ‘White Knight’ petioles, the role of plant growth regulators in adventitious shoot regeneration and shoot multiplication, and the effect of auxins on the rooting ability of <i>Philodendron</i> ‘White Knight’ microshoots. There are few stages in plant micropropagation. The establishment of aseptic culture is the first and most important stage. For <i>Philodendron</i> ‘White Knight’, aseptic petiole explants (100%) were obtained after treatment with 40 mg L⁻¹ Ag NPs for 60 min. This was followed by adventitious shoot induction, and the highest rate of adventitious shoot induction (52.6%) and the maximum shoot number (13.9 shoots per petiole) were achieved on Murashige and Skoog shoot multiplication B (MS-B) medium with 20 µM of 2-isopentenyl adenine (2-IP) and 5.0 µM of naphthalene acetic acid (NAA). The shoot multiplication stage was achieved with the highest number of shoots (34 shoots per shoot tip) with a length of 5.1 cm, which was obtained on MS-B medium with 5.0 µM 2-IP and 2.5 µM NAA. All the microshoots produced roots during the root induction stage with the maximum root number (8.2 roots per shoot), and the greatest plantlet height (9.1 cm) was achieved on half-strength Murashige and Skoog medium containing indole-3-butyric acid (10.0 μM). The rooted plantlets of <i>Philodendron</i> ‘White Knight’ were transplanted into a substrate composed of 10% peat moss, 50% orchid stone, and 40% coconut husk chips and acclimatized in a greenhouse environment, achieving a survival rate of 100%. This micropropagation protocol can be used for the commercial production of <i>Philodendron</i> ‘White Knight’.