Rapid Micropropagation Using Nodal Explants of Bacopa monnieri (L.) Pennell: An Endangered Medicinal Plant

Abstract

This study evaluated an in vitro micropropagation protocol for Bacopa monnieri using nodal explants. Healthy nodal segments were collected from nursery-grown plants, surface sterilised, and cultured on Murashige and Skoog medium supplemented with different plant growth regulators. The sterilisation sequence consisted of 1% Bavistin for 10 min, 70% ethanol for 30 s, and 0.01% mercuric chloride for 5 min, followed by repeated rinsing with sterile distilled water. For shoot initiation, nodal explants were cultured on MS medium containing different concentrations of 6-benzylaminopurine. Among the tested treatments, MS medium supplemented with 3.0 mg/L BAP showed the strongest shoot initiation response, with bud break observed within 7–10 days. For shoot multiplication, the best response was obtained on MS medium supplemented with 4.0 mg/L BAP and 0.5 mg/L NAA. Elongated shoots were transferred to half-strength MS medium containing IBA at 0.1–0.4 mg/L for root induction, and the highest rooting response was observed at 0.4 mg/L IBA. Rooted plantlets were subsequently acclimatised through primary and secondary hardening before transfer to soil conditions. The study indicates that nodal explants can be used for rapid in vitro propagation of B. monnieri, although further validation with additional replication and statistical analysis is required. All experiments were conducted in triplicate, and the data were subjected to appropriate statistical analysis.