Adventitious shoot production from calloid cultures of banana.

Isolated tips (approx. 2 mm long) from aseptic, multiplying shoot cultures of the triploid dessert banana clone 'Highgate' were tested for their morphogenetic responsiveness to hormone treatments on semisolid media. Medium containing Murashige and Skoog (1962) salts, p-chlorophenoxyacetic acid, and kinetin produced a compact calloid mass. Protuberances disclosed by SEM as rounded, button-shaped, and pointed outgrowths resembling fasciated shoots were formed in profusion. Sections showed many meristematic regions, some associated with distinct leaf primordia. Formation and growth of successive leaves yielded small, elongated, adventitious shoots with constricted bases. Transferral to a basal MS medium with 1 mg/l 1-naphthaleneacetic acid (NAA) led to the formation of rooted plantlets.