The influences of growth regulators and culture medium composition on shoot-tip cultures of edible canna

Abstract

Explants obtained from the terminal buds of edible canna (Canna edulis Ker-Gawl.) were aseptically cultured with, different combinations of auxins (NAA, IBA), cytokinins (BA, KN, 2ip), and culture media (B5, 1/2MS, MS), to establish a tissue culture system for this species. The combination of NAA or IBA with BA induced optimal explant growth, and when the explants grew substantially, TIBA promoted lateral shoot growth. For explant growth, the optimal concentration of NAA was 0.1-0.5 mg L-1, irrespective of the BA concentration adopted, and the optimal concentration of BA was 0.5-1 mg L-1. Some of the explants formed callus-like or protocorm-like tissues. Among the three culture media, B5 gave the highest survival rate of explants (92%), followed by 1/2 MS (72%) and MS (52%). In these combinations, micronutrients followed by macronutrients and vitamins, were found to be most important components for explant survival. Gellan gum at 2.5 g L-1' was a superior supporting/gelling material for explant growth compared to a filter paper-bridge with liquid, medium or 4 g L-1 agar. Our results indicate that multiple plantlet propagation can be performed routinely, while callus formation remains a time-consuming endeavor.