Abstract

The micropropagation of Guadua angustifolia Kunth, commonly known as giant bamboo, using semi-solid culture medium, is reported to have low multiplication rates. This study evaluated the multiplication index of G. angustifolia in a temporary immersion system (RITA^®), comparing results with those obtained using a semi-solid culture medium. The treatments consisted of either three or four 2-min immersions per day and use of semi-solid culture medium, which consisted of MS supplemented with 3.0 mg L^-1 of the cytokinin benzylaminopurine (BAP). Equipment consisted of 20 vessels for automated RITA^®, each containing 200 ml of culture medium. Immersions were performed for 2 min at two different frequency intervals (6 and 8 h). Large clumps of G. angustifolia with 1, 2 or 3 stems were inoculated depending on the treatment. Best results were obtained with four immersion cycles per day (every 6 h), with a multiplication index of 2.7 shoots per original explant (axillary buds) and greater rhizome growth. Overall, the temporary immersion system performed better than the semi-solid medium in terms of shoot multiplication rates and rhizome growth. Further studies should be conducted to develop an application for RITA^® for use in the commercial production of G. angustifolia.

Key words: Giant bamboo, temporary immersion system RITA, rhizome.

Abbreviation

BAP, 6-Benzylaminopurine; 2,4-D, 2,4-dichlorophenoxyacetic acid; GA, gibberellic acid; IAA, indoleacetic acid; MS, Murashige and Skoog (1962); NAA, naphthalene acetic acid.