Development of an Efficient Micropropagation Protocol for Philodendron erubescens ‘Pink Princess’ Using a Temporary Immersion System and Assessment of Genetic Fidelity

Philodendron erubescens ‘Pink Princess’, a highly sought-after ornamental cultivar, faces propagation challenges via conventional means, making in vitro culture a necessary alternative for large-scale production. This research aimed to establish an efficient micropropagation protocol by optimizing the shoot multiplication phase in a Temporary Immersion Bioreactor (TIB) and subsequently assessing the genetic fidelity of the regenerated plants. Shoot induction was evaluated in a TIB system with an immersion frequency of 4 minutes every 8 hours. Among the tested cytokinins, liquid Murashige and Skoog (MS) medium containing 1.0 mg/L 6-benzylaminopurine (BAP) provided the optimal conditions for shoot proliferation. While the TIB system was highly effective for shoot multiplication, it proved suboptimal for root induction. Therefore, rooting was optimized on a semi-solid medium, where MS medium supplemented with 0.5 mg/L indole-3-acetic acid (IAA) was identified as the most effective treatment, yielding an average of 3.0 well-developed roots per explant (1.1 cm in length) within 30 days. For ex vitro acclimatization, a substrate mix of peat moss, perlite, and vermiculite (2:1:1, v/v/v) ensured a 100% survival rate. Critically, genetic fidelity analysis using RAPD markers revealed monomorphic banding patterns between the micropropagated plantlets and the mother plant, confirming their genetic uniformity and true-to-type nature. The established protocol provides a complete, reliable, and commercially viable strategy for the mass propagation of P. erubescens ‘Pink Princess’, effectively overcoming the limitations of classical propagation techniques.