STRATEGIES TO IMPROVE ROOTING AND ACCLIMATIZATION OF ALBIZIA AMARA (ROXB.) BOIV

Abstract

The success of acclimatization and plant survival greatly depends on the quality of roots. The present study explores a reproducible
and efficient protocol for enhancing the acclimatization of micropropagated plants of Albizia amara by in vitro root induction using
auxin dip followed by ex vitro root development and biohardening. Successful in vitro root induction by the basal dipping of
microshoots in an auxin solution for short periods and subsequent transfer to growth regulator-free medium in dark conditions for 6
to13 days at a temperature of 26-28˚C has been reported. In the present study, Indole-3-Acetic Acid (IAA), Indole-3-Butyric Acid
(IBA), and α-Naphthalene Acetic Acid (NAA), and different strengths of MS medium (full, half and 1/4) were tested. Shoots of size
2-3 cm were dipped in various concentrations (30, 40, 50, 60, 70, 90, 100 mg/l) of auxin solution for different time periods
(15min, 30min, 60 min for each conc.). Highest root induction was observed on quarter strength MS medium and of the different
auxins tested maximum root induction (92%) was achieved when shoots were dipped in 60mg/l NAA for one hour. Shoots with
root primordia were placed in a sterilized potting mix (Soil:Peat:Vermiculite:Perlite in 2:1:1:1) supplemented with bioinoculants
for root elongation and biohardening. This strategy of employing a combination of both in vitro and ex vitro methods for root
development enhanced the plant survival rate to a maximum of 82%.