In the present study were evaluated in vitro rooting of apical buds of grape rootstocks R110 and SO4, using 0, 15, 30, 45 y 60 g·liter-1 of sucrose in the media culture and containers with and without complementary gas exchange. After establishment, the explants were kept in an incubation room at 25 ± 2 °C, with a luminous intensity of 76 µmol·m-2·s-1 and a 16-hour photoperiod. After 13 days of growth, rooting percentage and number of roots per explant showed superior values for the medium without sucrose, where there was a higher osmotic potential. The culture medium, in the containers without gas exchange, lost three times less water and the explants showed higher rooting and number of roots, than those developed in containers with gas exchange. Rooting started at seven and eight days after the explants were established, but rootstock R110 was superior to SO4 during all evaluation days.

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