Optimization of plant growth regulators for in vitro mass propagation of Philodendron cv. Birkin through shoot tip culture

In vitro cultures provide a promising tool for large-scale multiplication of valuable plant species with an important role in the global ornamentals industry. In the current investigation, a rapid and efficient protocol was described for in vitro mass propagation of attractive ornamental plant Philodendron cv. Birkin through shoot tip culture. In shoot proliferation stage, 11 treatments of plant growth regulators were evaluated. The highest shoot multiplication was achieved by culturing explants in MS medium containing 3 mg/l benzyladenine (BA) and 0.5 mg/lit indole-3-butyric acid (IBA), resulting in average of 16.65 shoots per explant over a four weeks period. To induce adventitious root formation, the regenerated shoots were subsequently transferred to MS media supplemented with various concentrations of IBA and naphthalene acetic acid (NAA) (0.5-2 mg/l). In this regard, the superior performance of IBA compared with NAA was observed with the best response achieved using 1 mg/l IBA (resulting in a 95% rooting rate) with an average of 6.13 roots per shoot and the root length of 2.59 cm. Finally, the obtained plantlets were successfully acclimatized in a greenhouse, with 100% ex vitro survival rate. This established protocol can serve as an effective alternative to classical propagation methods for mass multiplication of this valuable decorative plant.