An efficient micropropagation protocol for teak (Tectona grandis L.) using nodal explants and ex vitro rooting

Teak (Tectona grandis L.) is one of the most valuable tropical hardwood species; however, large-scale propagation of elite genotypes is constrained by poor seed germination and limited vegetative multiplication. The present study describes an efficient micropropagation protocol using nodal explants collected from a 20-year-old elite teak plus tree (var. Teli). Approximately 80% aseptic culture establishment was achieved on Woody Plant Medium (WPM) supplemented with 0.5 mg L⁻¹ 6-benzylaminopurine (BAP), with axillary bud break occurring within 3–4 days. Shoot multiplication was significantly influenced by growth regulator concentration, with the highest mean shoot number (3.92) recorded on WPM containing 5.0 mg L⁻¹ BAP, although optimal shoot quality and elongation were obtained at 0.5 mg L⁻¹ BAP. Ex vitro rooting was successfully induced by pulse treatment of microshoots with 1.0 mg L⁻¹ indole-3-butyric acid (IBA), followed by direct transfer to potting substrates. A soil mixture containing soil, sand, cocopeat, and vermicompost resulted in the highest survival rate (90%) during hardening. The protocol offers a simplified, cost-effective, and reliable method for rapid clonal propagation of mature teak trees, suitable for large-scale plantation forestry.