Integrated in vitro regeneration and ex vitro establishment of Syngonium podophyllum 'Pink Allusion': optimization of growth regulators and acclimatization substrates.

Syngonium podophyllum Schott. 'Pink Allusion' is an economically important ornamental foliage plant valued for its attractive leaves and adaptability to indoor environments. However, conventional vegetative propagation is limited by low multiplication rates and the potential transmission of pathogens. Therefore, this study aimed to establish an efficient protocol for in vitro regeneration, rooting, and ex vitro acclimatization of S. podophyllum through three sequential experiments. In the first experiment, nodal explants were cultured on Murashige and Skoog (MS) medium supplemented with different combinations of thidiazuron (TDZ), 6-benzylaminopurine (BA), α-naphthaleneacetic acid (NAA), and gibberellic acid (GA₃) to optimize direct shoot regeneration and vegetative growth. The highest regeneration rate (4.30 shoots per explant) was obtained on MS medium containing 2.0 mg L⁻¹ TDZ and 0.25 mg L⁻¹ NAA, while superior shoot elongation, petiole growth, and leaf expansion were achieved with 1.0 mg L⁻¹ TDZ and 0.5 mg L⁻¹ NAA. In the second experiment, regenerated shoots were rooted on media containing different concentrations and combinations of indole-3-butyric acid (IBA) and NAA. The highest root number (5.75 roots per plantlet) was recorded with 0.5 mg L⁻¹ IBA, whereas the combination of 0.5 mg L⁻¹ IBA and 0.1 mg L⁻¹ NAA produced the longest roots (7.37 cm). Moreover, 1.0 mg L⁻¹ IBA significantly enhanced plantlet growth and biomass accumulation. In the third experiment, rooted plantlets were acclimatized in greenhouse conditions using cocopeat-perlite and peat moss-perlite substrates. All plantlets survived acclimatization, achieving 100% survival. Peat moss-based substrates significantly improved root development, leaf growth, biomass accumulation, and photosynthetic pigment content. Overall, the optimized protocol provides a reliable and efficient system for large-scale propagation and future biotechnological applications of S. podophyllum 'Pink Allusion'.