Optimization of Growth Condition for Micropropagation of Banana (Musa spp.) in a Temporary Immersion Bioreactor System

Abstract

This study aimed to optimize growth conditions for micropropagation of banana (Musa spp.) using temporary immersion bioreactors (TIBs). The experiment evaluated the influence of two factors: feeding frequency and cytokinin concentration. Two feeding schedules were tested: 6 immersions per day and 8 immersions per day. The TIBs were submerged in the culture medium for a set duration during each immersion, with the remaining time allowing for gas exchange and drainage. The culture medium was supplemented with Benzylaminopurine (BAP), a plant growth regulator, at five different concentrations: 2.5 mg/L, 3.5 mg/L, 4.5 mg/L,5.5 mg/L and 6.5mg/L. BAP promotes shoot multiplication, a crucial aspect of micropropagation. All other culture conditions, such as light intensity, photoperiod, and medium composition, were kept constant throughout the experiment. Following an incubation period, banana microshoot growth parameters were assessed. The parameter taking is number of new shoots produced per initial explant. The results revealed that a BAP concentration of 4.5 mg/L yielded the most optimal growth for the banana microshoots. This suggests that 4.5 mg/L BAP effectively balances shoot proliferation without compromising shoot development. Furthermore, the experiment demonstrated a significant improvement in growth parameters when the feeding frequency was increased to 8 immersions per day compared to 6 immersions per day. This indicates that more frequent exposure to the culture medium enhances nutrient and oxygen availability, leading to better micropropagation outcomes. This study identified a combination of 4.5 mg/L BAP and a feeding schedule of 8 immersions per day as the optimal conditions for micropropagation of banana in TIBs. These findings can contribute to improved efficiency and productivity in banana micropropagation for commercial or research purposes.