Effect of Explant Source on Axillary Shoot Multiplication During Micropropagation of a Rare Medicinal Plant — Wattakaka volubilis (L f) Stapf

Abstract

Nodal explants of in vivo plants and in vitro seedlings of Wattakaka volubilis were cultured on Murashige and Skoog medium fortified with various concentrations of cytokinins — BA (0.5–5 mg l⁻¹), KN (0.5–10 mg l⁻¹),TDZ (0.05–1 mg l⁻¹) either singly or in combination with NAA (0.1 mg l⁻¹). KN proved best for inducing healthy shoots in both in vitro and in vivo derived explants. Maximum number of shoots (14.1±0.84) with 80% regeneration frequency was obtained from nodal explants of seedlings cultured on 5 mg 1⁻¹ KN + 0.1 mg l⁻¹ NAA. In vivo nodal explants produced a maximum of 4.2 shoots on MS medium fortified with 2 mg l⁻¹ BA+0.1 mg l⁻¹ NAA. The differentiated shoots from both could be rooted with 85% frequency on 1/2 strength MS medium (1% sucrose) with 0.6% agar + 1 mg l⁻¹ IBA + 0.2 mg l⁻¹ KN. Rooted shoots were transplanted to vermiculite-soil (3:1) mixture in polyethylene covered pots with 45% transplantation success. Peroxidase isozymes (native PAGE) analysis helped to verify the variation in regenerated plants.