In Vitro Induction of Callus and Flowers in Immature Oil Palm Inflorescences

This work aimed to investigate the effects of different combinations of auxin (0, 225 and 450 µM Picloram) and Murashige and Skoog salts (50% and 100% MS salt concentrations, respectively named as ½ MS and MS) in mediate the induction of callus and flowers from immature inflorescences (developmental stages I-9, I-12 and I-15) of the oil palm BRS – Manicoré hybrid. In I-9 inflorescence explants, the rate of callus induction was 17% higher in ½ MS than in MS; while in both I-12 and I-15 inflorescence explants, callus induction was over than 95% regardless of the MS salt concentration. The higher rate of callus induction in I-9 inflorescences was mediated by 450 µM Picloram, while the callus induction rates for either I-12 or I-15 inflorescences were higher than 92% regardless of Picloram concentration. Floral induction was lower in I-9 inflorescence explants (45% floral induction rate) than in both I-12 and I-15 inflorescence explants (floral induction rate higher than 90%). Our results suggest that Picloram (450 µM) and MS salts concentrations (½ MS) led to the highest rates of calluses and flowers induction in younger inflorescence explants (I-9); however, the medium composition is indifferent on callus and flower induction in I-12 and I-15 inflorescences.