Micropropagation of Banana cv. Rasthali (AAB)

Abstract

An efficient and effective in vitro regeneration protocol was developed and standardized for the banana cultivar Rasthali using shoot tip explants. The explants were placed on Murashige and Skoog (MS) medium enriched with different concentrations of benzyl aminopurine (BAP) and thidiazuron (TDZ) to promote shoot induction and proliferation, whereas indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) were utilized to induce rooting. Among the various treatments, the MS medium fortified with 3.5 mg/L BAP produced the highest shoot proliferation, with an average of 4.67 shoots per explant. This response was superior to that observed with TDZ at 0.2 mg/L, which produced an average of 3.33 shoots per explant. A synergistic effect was observed when BAP (3.5 mg/L) and TDZ (0.2 mg/L) were combined, resulting in up to 6.67 shoots per explant. Notable improvement in shoot elongation was observed in MS medium enriched with 0.2 mg/L GA₃, producing shoots reaching up to 9.4 cm in length. Rooting responses varied with auxin concentration, with the highest root number observed at 2.5 mg/L IBA. Rooted plantlets were successfully hardened in a soil mixture consisting of garden soil, farmyard manure, and sand in a 2:1:1 ratio, resulting in a survival rate of 90% under ex vitro conditions. The regenerated plants exhibited normal morphology, closely resembling the mother plants. This optimized protocol offers a reliable and scalable approach for the commercial micropropagation of banana cv. Rasthali.