In vitro regeneration of avocado (Persea americana Mill.) through growth regulator-induced shoot induction

Avocado (Persea americana Mill.), the only major fruit of the Lauraceae family, is valued for its nutrition. Traditional methods like seed propagation and grafting face issues of variability and low success. In vitro regeneration offers a better alternative for clonal uniformity and mass propagation. This study examined sterilizing techniques to reduce contamination and optimize shoot induction from nodal segments and apical meristems using different doses of plant growth hormones. Surface sterilization with 2.0% sodium hypochlorite (NaOCl) for 5 minutes significantly reduced microbial contamination (12% in nodal segments and 23% in apical meristems) while maintaining excellent survival rates (82% and 69%, respectively). Explants were cultivated on full-strength Murashige and Skoog (MS) medium that was enhanced with various BAP, kinetin, and TDZ combinations. A study of explants from the nodal segments and apical meristem showed that the nodal segments reacted better to BAP 1.5 mg/L treatment. Compared to apical meristem explants, nodal segment explants induced early shoots more quickly (34.43 and 36.67 days). At 40, 60, and 90 days following initiation, nodal segment explants had more shoots per explant (1.67, 2.00, and 2.33, respectively) than apical meristem explants (1.33, 1.77, and 2.00, respectively). Similarly, the shoot length of nodal segment explants was longer than that of apical meristem explants, measuring 0.63 cm, 1.20 cm, and 1.57 cm at 40, 60, and 90 days after initiation, respectively, as opposed to 0.53 cm, 1.00 cm, and 1.13 cm. These findings demonstrate the exceptional capacity for regeneration of nodal segment explants and offer important information for refining avocado micropropagation methods for large-scale plant production.