In Vitro Propagation System for Proiphys amboinensis Using Twin-Scale Explants and Genetic Fidelity Assessment

Proiphys amboinensis has considerable potential as a commercial ornamental plant due to its attractive foliage, distinctive flowers, and long flowering period. This study established an in vitro micropropagation protocol and evaluated the genetic fidelity of regenerated bulblets using Inter Simple Sequence Repeat (ISSR) markers and flow cytometry. Twin-scale explants were cultured on Murashige and Skoog (MS) medium supplemented with 0, 0.5, 1.0, and 2.0 mg/L N6-benzyladenine (BA) for 12 weeks. Bulblet formation efficiency ranged from 60.00 ± 16.33% to 70.00 ± 11.55%, with no significant differences among treatments. A significant increase in bulblet number was observed at 1.0 mg/L BA compared with the control and 0.5 mg/L BA; however, bulblet fresh weight did not differ significantly among these treatments. Sucrose concentrations (30–90 g/L) had no significant effects on bulblet weight and diameter. Root induction was evaluated using indole-3-butyric acid (IBA) and α-naphthaleneacetic acid (NAA) at concentrations of 0–1.0 mg/L, with 0.5 mg/L IBA identified as the optimal treatment. Following acclimatization, regenerated bulblets exhibited high survival rates (90–100%). ISSR and flow cytometric analyses revealed no detectable genetic variation, with a consistent genome size between regenerated bulblets and the mother plants, indicating high genetic uniformity. The protocol provides a micropropagation system for P. amboinensis with high genetic fidelity, supporting its commercial and research potential.