Excised leaf explants of annatto (Bixa orellana L.) seedlings were cultivated on a Murashige & Skoog basal medium containing benzylaminopurine (BAP), kinetin (KN) and isopentenyl-adenine (2iP) individually or in combination, each at concentration of 0.5mg/l, with the purpose of evaluated the best cytokinins or cytokinins combination for shoot bud formation. After 60 days, regenerated shoots were transferred to half strenght MS medium without growth regulators. Best shoots were observed where KN and BAP were added in combination. Isolated KN was ineffective for shoot bud formation. The maximum average number of shoot buds per leaf explant was obtained on medium with BAP, KN and 2iP in combination and on medium supplied of isolated BAP.
annatto; Bixa orellana L; micropropagation; cytokinins
