In vitro callus induction and indirect organogenesis of Mentha piperita (L.) - an aromatic medicinal plant

The effect of different concentrations and combinations of plant growth regulators were tested for in vitro callus induction and indirect plant regeneration of Mentha piperita L. from young leaves and internodal explants. Greenish, organogenic and nodular nature of callus was achieved only from leaf disc explant when cultured on MS medium containing 1.5 mg/l NAA+ 0.2 mg/l BAP and then subsequent plant regeneration was obtained on MS medium supplemented with 2.0 mg/l BAP+0.5mg/l NAA from leaf derived callus.  The highest frequency of shoot regeneration (90%) with the maximum number of shoots (15.1±0.11) was achieved in this medium. In vitro raised microshoots showed 90% response with maximum number of roots (16.3±0.23) on 1.0 mg/l IBA after 11-12 days. Then in vitro rooted plantlets were move to polybags bearing soil and vermiculite mixture in 1:1 ratio for hardening and hardened plantlets showed 95% survivability on field conditions.