In Vitro Multiplication and Acclimatization of Banana (Musa spp.) Plantlets

Banana (Musa spp.) is a horticulturally important fruit crop of economic significance, particularly in tropical and subtropical regions of the world. Vegetative propagation of banana via suckers is hindered by a low multiplication rate and high susceptibility to diseases. The current study optimized efficient protocols for large-scale in vitro multiplication and acclimatization of two commercially valued banana cultivars (William and Grand Naine) initially propagated from shoot tip explants. Clusters of shoot buds (1-2 cm) were multiplied on the Murashige and Skoog (MS) medium consisted of different concentrations (0.5, 1.0, 2.0, and 3.0 mg l-1) of benzyl adenine (BA). Medium comprised of different concentrations of activated charcoal (0.5, 1.0, 1.5, and 3.0 mg l-1) was used for healthy shoot and root development. Acclimatization of the plantlets (40 cm) in the greenhouse was carried out on different soils, i.e., peatmoss, river sand, clay soil, hill sand, and desert sand. Results revealed that significantly highest shoot bud multiplication (Avg. 21.2), and plantlet formation was obtained in cv. Grand Naine on the MS medium consisted of 3.0 mg l-1 BA. Significantly highest leaf number (4 leaves), leaf length (10.7 cm), root number (12 roots), and root length (13 cm) were noted on the MS medium consisted of 3.0 mg l-1 activated charcoal, 0.1 mg l-1 naphthalene acetic acid (NAA). Plantlets (15 cm) developed healthy shoot and roots during in vitro growth and were shifted in the greenhouse for acclimatization and further growth. Significantly higher survival rate (96%) of the acclimatized plantlets in the greenhouse and healthy growth was noted on the soil medium consisted of river sand in cv. Grand Naine after 1M (month). Protocols optimized for in vitro and ex vitro growth of the two elite banana cultivars (William and Grand Naine) will benefit to the farmers for large-scale cultivation in the area and across the world.