In vitro propagation through ex vitro rooting of a medicinal spice Piper longum Linn

Successful in vitro propagation through ex vitro rooting mechanism has been achieved in Piper longum by nodal shoot segment cultures. Shoot tip explants were less proliferative compared to the nodal meristems. The explants were sterilized using 0.1% HgCl2 and cultured on Murashige and Skoog (MS) medium with various concentrations of growth regulators. MS medium supplemented with 1.0 mg/L 6-benzylaminopurine (BAP) was found suitable for bud breaking within four weeks. Kinetin (Kin) was not reported impressive compared to BAP in culture induction response. The shoots were multiplied and elongated on MS medium supplemented with 0.5 mg/L each of BAP and Kin and 0.1 mg/L indole-3 acetic acid (IAA), where the shoots were elongated up to 5.8 cm length. Rooting and acclimatization was achieved by ex vitro rooting methods using 300 mg/L indole-3 butyric acid (IBA) for 5 min, and 5.3 roots with 3.2 cm average length were observed. The rooted shoots were transferred to the greenhouse for acclimatization. The hardened plantlets were transferred to earthen pots and maintained in the greenhouse. Normal flowering was observed in micropropagated plants of P. longum.