An optimised in vitro propagation protocol for scarlet banana (Musa coccinea Andrews) promoting efficient shoot multiplication, rooting and acclimatisation

Abstract

Scarlet banana (Musa coccinea Andrews) is a valuable ornamental species, but its commercial production remains constrained by low multiplication rates, non-uniform planting material and limited availability of species-specific propagation protocols. This study developed a comprehensive in vitro regeneration protocol for M. coccinea by sequentially optimising basal medium, cytokinin and auxin concentrations, rooting conditions and acclimatisation substrates. To our knowledge, this is the first integrated protocol for M. coccinea that covers shoot initiation, shoot multiplication, root induction and ex vitro acclimatisation in a single regeneration system. Among the basal media tested, Murashige and Skoog (MS) medium produced the highest survival rate (88.88 %), the highest shoot initiation percentage (88.88 %) and the greatest shoot height (4.20 cm). During shoot multiplication, 2.0 mg L-1 6-benzylaminopurine (BAP) produced the highest number of shoots per explant, while the combination of 2.0 mg L-1 BAP and 0.3 mg L-1 α-naphthaleneacetic acid (α-NAA) further enhanced shoot proliferation and produced vigorous, compact shoots. Root induction was most effective on medium supplemented with 0.5 mg L-1 α-NAA, which produced the greatest root number and root length. During acclimatisation, the substrate composed of alluvial soil, burnt rice husk and sand supported the highest survival rate and strongest vegetative growth. The study demonstrated that optimised nutrient composition, hormonal balance and substrate selection are critical for efficient regeneration. The optimised protocol provides a practical and reproducible system for large-scale production of uniform and high-quality M. coccinea plantlets for ornamental horticulture.