Optimized Micropropagation for the Production of Disease-Free Planting Materials of Zingiber officinale Roscoe ‘Bentong’

Ginger (Zingiber officinale Roscoe) is a high-value spice and medicinal crop, yet its global production is constrained by infrequent sexual reproduction and pathogen accumulation in vegetatively propagated rhizomes. Micropropagation offers a means of producing disease-free planting materials; however, genotype-dependent protocols with well-defined hormonal requirements remain limited. This study aimed to establish an efficient in vitro protocol for the sustainable production of disease-free planting materials of ‘Bentong’ ginger. The synergistic effects of 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) were evaluated for shoot multiplication, while Murashige and Skoog (MS) medium at quarter, half, and full-strength supplemented with 3 µM NAA and varying sucrose concentrations was assessed for rooting and acclimatization. MS medium containing 3% sucrose, 12 µM BAP, and 1.5 µM NAA significantly enhanced shoot proliferation (>6 shoots per explant). However, in subsequent subcultures, continued BAP supplementation suppressed shoot growth and induced callus formation in some cultures, likely due to residual BAP accumulation; hormone-free MS medium achieved comparable multiplication rates. Rooting was optimized on quarter-strength MS medium with 2% sucrose and 3 µM NAA, resulting in vigorous root development and successful acclimatization. The optimized protocol provides a reliable platform for large-scale production of disease-free planting materials of ‘Bentong’ ginger. By reducing dependence on rhizome-based propagation, this approach offers a sustainable strategy to strengthen 'Bentog' ginger production systems and enhance food security.