Optimization of in vitro and ex vitro regeneration and micromorphological studies in Basella alba L.

Abstract

The optimum concentrations of the plant hormones for in vitro regeneration and subsequent effect of auxins on rooting (in vitro and ex vitro) of shoots of Basella alba L. have been investigated in present study. Nodal shoot segments were used as explants to initiate the cultures. The bud breaking from explants was observed within 1week of incubation on agar gelled Murashige and Skoog's (MS) medium. Multiple axillary shoots (7.30±0.56 shoots per explant) were induced on MS medium supplemented with 2.0mg/L 6-benzylaminopurine (BAP). The shoots were multiplied (maximum 17.10±0.44 shoots per explant) on the same medium fortified with 0.5mg/L each of BAP and Kin (Kinetin) +0.1mg/L IAA. These shoots were excised and rooted in vitro (10.73±0.92 roots per shoot) on half-strength MS medium augmented with 2.0mg/L indole-3 butyric acid (IBA). Hundred percentage success rates have been achieved by ex vitro rooting of the in vitro regenerated shoots with IBA at 300mg/L. The in vitro and ex vitro rooted shoots were acclimatized in greenhouse and subsequently transferred to the natural field conditions where 100% survival rate was reported. The ex vitro rooting method was found more advantageous than in vitro rooting in terms of time, energy and survival percentage of B. alba. A comparative foliar micromorphological study of B. alba was conducted to understand the micromorphological changes in plants while shifting from in vitro to the in vivo conditions in terms of variations in stomatal index, venation pattern and vein density, and the arrangement of crystals. The study could help in understanding the response of in vitro raised plants towards in vivo environment.