Micropropagation of <i>Guadua angustifolia</i> Kunth (Poaceae) using a temporary immersion system RITA^®

Abstract

The micropropagation of Guadua angustifolia Kunth, commonly known as giant bamboo, using semisolid 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.

Keywords: Giant bamboo, temporary immersion system RITA, rhizome