ADVENTITIOUS SHOOT INDUCTION FROM LEAF EXPLANTS OF RIBES MAGELLANICUMCULTURED IN-VITRO

Several factors were studied on adventitious shoot induction from leaf explants of Ribes magellanicum cultured in vitro: type of explant, po sition of the leaves along the stem and growth regulators. Explants wi th petiole and complete leaf lamina presented the highest percentage o f organogenesis. The position of the leaf along the shoot strongly aff ected the induction capacity. The percentage of explants with adventit ious shoots was maximum (53%) when using apical leaves, with an averag e of three shoots per explant. 6-benzylaminopurine (BA) and N-benzyl-9 -(2-tetrahydropyranyl)-adenine (BPA) had a significantly higher promot ive effect than 6-(tau-tau-dimethylallylamino)purine (2iP) or kinetin on induction of adventitious shoots. Cytokinin concentration significa ntly affected shoot production, best responses being obtained with 4.4 4 to 8.88 micrometers. No significant differences were observed betwee n alpha-naphthaleneacetic acid (NAA) concentrations but 0.5 micrometer s NAA usually promoted the highest number of non-vitrified shoots per explant. The results of this work show that R-magellanicum can be indu ced to form adventitious shoots from leaf explants cultured in vitro.