The objective of this work was to test the agar action and its partial and total substitution for cassava starch as gelling agents in the culture media of banana and pineapple. Axillary buds of 'Rio Branco' and 'Quinari' cultivars were established and the multiplication rate evaluated by four subcultives in media with 2 mg.L-1 BAP and 0,25 mg.L-1 NAA, with the following combination of gelling agents: M1: agar (5 g.L-1), M2: agar (2,5 g.L-1) + cassava starch (60 g.L-1), M3: cassava starch (60 g.L-1), and M4: agar (2,5 g.L-1) + cassava starch (30 g.L-1). In a second experiment, for three successive subcultivation shoots of banana, 'Grand Naine' cultivar were evaluated in media composed with the following gelling treatments: MM1: agar (6 g.L-1); MM2: agar (3 g.L-1) + cassava starch (30 g.L-1); MM3: cassava starch (60 g.L-1) and; MM4: stationary liquid medium. To these media were added 0, 2, 4 and 6 mg.L-1 BA. To pineapple it was verified similar results when agar was completely substituted for cassava starch as gelling agent, but the combination agar + cassava starch provided the worse results when compared with gelling agents used separately. For banana shoots multiplication, the isolated or combined use of cassava starch did not improve the multiplication rates. The best results were obtained in medium with 2 mg.L-1 BA and agar as gelling agent. The shoot cultivation in liquid medium presented the lowest multiplication index.
Musa sp.; Ananas sp.; micropropagation; cassava starch
