Temporary Immersion Bioreactor (TIB) System for Large-Scale Micropropagation of Musa sp. cv Kluai Numwa Pakchong 50

Conventional in vitro propagation using semisolid Murashige and Skoog (MS) culture systems is costly, labor-intensive, and requires substantial space for large-scale plant production. This study investigated the application of a temporary immersion bioreactor (TIB) system for the micropropagation of the banana cultivar Kluai Numwa Pakchong 50, as a promising platform for economical commercial production. The cultivation parameters affecting plantlet multiplication, including plant growth regulator (PGR) use, explant density, and immersion frequency, were examined. Additionally, the ex vitro acclimatization of well-developed in vitro plantlets was also evaluated. Using liquid MS medium supplemented with 7.5 mg/L 6-benzylaminopurine (BAP) in the TIB system yielded significantly better results than the conventional semisolid MS control system, producing more shoots (5.60 shoots/explant) and leaves (2.80 leaves/explant) with longer shoot length (2.19 cm). Optimal conditions in the TIB system included an inoculum density of five explants per culture vessel and an immersion frequency of once every 6 or 8 h for 2 min. For root induction, 0.5 mg/L indole-3-butyric acid (IBA) proved more effective than 1-naphthaleneacetic acid (NAA). After 30 days of ex vitro acclimatization, plantlets regenerated from the TIB system demonstrated high survival rates, vegetative growth performance, and root formation efficiency comparable to those from the semisolid culture system. These findings establish the TIB system as a promising platform for the mass propagation of the Kluai Numwa Pakchong 50 banana. The protocol developed in this study could potentially be adapted for large-scale production of other banana varieties.