Microcuttings of gardenia (Gardenia jasminoides Ellis) harvested from shoot-tip subcultures were placed for rooting in vitro with or without IBA (1 mg l^-1) and ex vitro into a peat-perlite substrate (1:1 v/v) under a low-pressure fog system. Zero, 5 and 10 days after planting, basal portions (0.5 cm in length) from the microcuttings were taken for measuring the concentrations of reducing (glucose, fructose), non-reducing (sucrose) and total sugars (glucose, fructose, sucrose). Rooting evaluation was made on a 25-day long period by taking data every 5 days. The proportions of rooted microcuttings were 100 % in vitro with IBA vs 97 % without IBA and 92 % in ex vitro conditions. However, microplant establishment in peat-perlite (1:1 v/v) substrate was higher for microcuttings rooted ex vitro (only 1 % losses) than for those rooted in vitro (15 % losses). In the first 5 days, the reducing, non-reducing and total sugars of the microcutting basal portions increased more rapidly for in vitro rooting than for ex vitro rooting, followed in in vitro conditions by a noticeable decrease of these sugars until the 10th day of culture. On the contrary, the reducing, non-reducing and total sugars increased slightly from the 5th to the 10th day in microcuttings rooted ex vitro. The emergence of the roots in in vitro and ex vitro conditions was noticed on the 7th and 10th day after planting, respectively.

Key words: Gardenia jasminoides, in vitro culture, micropropagation, reducing sugars, non-reducing sugars, total sugars.