Improved shoot organogenesis of gloxinia (Sinningia speciosa) using silver nitrate and putrescine treatment

An improved method for shoot organogenesis and plant regeneration in Sinningia speciosa was established. Leaf explants were cultured on Murashige and Skoog (MS) medium supplemented with different combinations of benzylaminopurine (BAP) and naphthalene-acetic acid (NAA) for shoot induction. MS media including BAP (2 mg/L) and NAA (0.1 mg/L) resulted in the highest efficiency in shoot regeneration per explant (12.3 ± 0.8) and in the greatest shoot growth (1.2 ± 0.1 cm) after 6 weeks. For improving shoot induction, the ethylene inhibitor silver nitrate and the polyamine putrescine were added to the regeneration medium. The addition of silver nitrate (7 mg/L) increased the shoot number (23.9 ± 1.6) and length (1.7 ± 0.2 cm) after 6 weeks. Similarly, putrescine (50 mg/L) improved the shoot number (19.2 ± 1.6) and growth (1.7 ± 0.2 cm). The rooted plants were hardened and transferred to soil with a 90% survival rate. This method of producing S. speciosa regenerated plants could be used as a possible micropropagation and plant transformation protocol.