Leaf bases of pineapple cultured on a shoot induction medium (SIM) produced protuberances followed by shoot-buds via direct organogenesis at a frequency of 46 %. When 8 mM glutamine (gln) was a supplement to SIM (SIM8gln), the regeneration rate increased to 70 %, thus suggesting that 8mM gln increased explant competence for organogenesis. Besides this, shoot vigor was strongly enhanced in SIM8gln. Other gln concentrations (16 or 32 mM) evoked a lower frequency of shoot-bud induction and number of regenerated shoots per explant when compared to SIM8gln. In this study, it was defined that explant organogenic commitment to form shoot-buds occurred in the first 7 days of culture on SIM8gln. Thereafter, endogenous indole-3-acetic acid (IAA) and cytokinin (4... |