Abstract

High frequency shoot regeneration from in vitro derived leaf explants of Wattakaka volubilis (L.f.) Stapf was achieved through callus mediated organogenesis. Organogenic calli were induced from 20 day old aseptic seedling explants on Murashige and Skoog medium fortified with various concentrations and combinations of plant growth regulators, benzylaminopurine (BAP), α-naphthaleneacetic acid (NAA), indole 3-butyric acid (IBA) and gibberellic acid (GA₃). A mean of 8.6 shoots developed from organogenic callus induced from a 2 x 2 cm leaf explants on MS medium with 3% sucrose having 5.37µM NAA in combination with 2.22 µM BAP with 60% induction capacity. Further development of adventitious shoots could be achieved by sub culturing the callus to the same medium with 4.40 µM BAP and 0.288 µM GA₃. Organogenesis could not be achieved from the calli of ex vitro derived leaf explants. The developed shoots were rooted on half-strength MS medium with 1% sucrose, 4.90 µM IBA and 0.93 µM kinetin at a frequency of 85%. Well rooted plantlets were then transplanted to vermiculite soil (3:1) mixture in polythene covered pots kept under culture room conditions. Approximately 60% plantlets survived and grew into whole plants.

Key words:  Adventitious shoots, caulogenesis, organogenic callus-histology.

Abbreviation

Abbreviations: BAP, Benzyl-6-aminopurine; 2,4-D, 2,4-dichlorophenoxyacetic acid; IBA, indole-3-butyric acid; MS, Murashige and Skoog (1962) medium; NAA, α-naphthaleneacetic acid; TDZ, 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea (thidiazuron); FAA, formaldehyde acetic acid alcohol; GA₃, gibberellic acid; IAA, indoacetic acid; Kn, kinetin; TBA, tertiary butyl alcohol.