Micropropagation of Byrsonima basiloba

Byrsonima basiloba (murici) is a Cerrado shrub whose fruits are consumed fresh or processed. Like many native species, it is difficult [hard] to propagate sexually. This study aimed to develop an efficient micropropagation protocol for B. basiloba using explants from in vitro-germinated seeds (shoots and cotyledons). Seeds were disinfected and germinated on a water-agar medium. Buds and cotyledonary explants were excised and cultured through five successive subcultures on multiplication media based on full- or half-strength MS salts, supplemented with various combinations of 6-benzylaminopurine (BAP), indole-3-butyric acid (IBA), and kinetin (KIN), plus sucrose, myo-inositol, and agar. Furthermore, the effect of activated charcoal (AC) on shoot elongation was evaluated. No significant difference in multiplication rate was observed between full- and half-strength MS media. The most effective hormone combination for inducing sprouting was 0.5 mg L⁻¹ BAP, 1.0 mg L⁻¹ IBA, and 0.2 mg L⁻¹ KIN. The addition of AC aided shoot elongation; nonetheless, to maintain an adequate multiplication rate in medium containing AC, an increase in hormone concentrations was necessary. Rooting was achieved ex vitro by applying an IBA-fungicide-talc mix to the shoot base, resulting in a 54% rooting success rate, of which 88.9% were successfully acclimatized. The presence of auxin was indispensable for rooting.