Development of a direct regeneration protocol for mass multiplication of banana cultivar 'Rasthali' (AAB, Silk) using immature floral hands as explants

摘要

The present study confirms that immature male floral hands can efficiently be used for mass propagation of banana with minimal risk of contamination, as compared to shoot tips which are commonly employed by tissue culture companies toward the production of disease-free quality planting material. In this study, immature male floral hands of 'Rasthali' (AAB, Silk) were used as explants for direct regeneration. The male inflorescence with floral hands in whorl numbers ranging from 8 to 25 (outer to inner) were cultured on MS medium supplemented with different combinations of growth regulators, like BAP, IAA, picloram and kinetin. Earliest greening (14 days) and meristematic clump formation (24 days) were observed in MS medium supplemented with BAP alone. The number of meristematic clumps formed per explant depends on the size of the floral hands. MS medium supplemented with BAP and IAA was found optimal for shoot regeneration. A maximum of 28 shoots were obtained from a single meristematic clump. Thewell-developed shoots were transferred to MS medium with IBA, NAA and activated charcoal for rooting. The plantlets derived from male floral hands were genetically found to be true to type as confirmed by ISSR markers. The explants were free from contamination and phenolic exudation which are the major obstacles for in vitro culture of banana.