Sugarcane shoot formation in an improved temporary immersion system

A new protocol was established for sugarcane cv. C-1051-73 shoot formation in a temporary immersion system. The two-step protocol involves shoot forma tion in 50 mi of culture medium per explant and 1.0 mg 1(-1) paclobutrazol for 30 days followed by shoot elongation by exposure to 1.0 mg 1(-1) gibber ellic acid for 15 days. The multiplication rate was doubled in comparison w ith the conventional micropropagation protocol (Jimenez et al., 1995) and t he cost has been reduced by 46%. Three additional sugarcane varieties have been micropropagated according to this new protocol and results are compara ble. Temporary immersion-derived plants have also been compared with conven tionally propagated plants in sugarcane fields for more than 9 months and t heir agricultural indicators of performance are similar.