Samanhudi1,2*, Sri Hartati1,2, Muji Rahayu1, Andriyana Setyawati1, Retna Bandriyati Arniputri1, Iswahyudi1, Iga Widiana1, Itsnani Ratna Wulandari1 and Hassan Bashir3
1Department of Agrotechnology, Faculty of Agriculture, Universitas Sebelas Maret (UNS), Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126, Central Java, Indonesia; 2Center for Research and Development of Biotechnology and Biodiversity, Universitas Sebelas Maret (UNS), Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126, Central Java, Indonesia; 3Department of Agricultural Science, Faculty of Agriculture, Universitas Sebelas Maret (UNS), Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126, Central Java, Indonesia
*Corresponding author: samanhudi@staff.uns.ac.id
Optimization of growth regulator combinations is critical for developing cost-effective banana micropropagation protocols. This study compared the effects of coconut water combined with indole-3-acetic acid and indole-3-butyric acid on in vitro banana multiplication and rooting. Analysis of variance revealed distinct response patterns between auxin types: IAA treatments showed significant main effects of coconut water on shoot emergence time, shoot height, shoot number, and root number, whereas IBA treatments primarily exhibited significant interaction effects on temporal parameters (shoot, root, and leaf emergence) and shoot multiplication. The fastest organogenesis occurred with 75 mL/L coconut water + 0.5 ppm IBA, while maximum shoot multiplication was achieved with 225 mL/L coconut water without IBA supplementation. IBA treatments produced substantially longer roots than IAA, with maximum root proliferation at 75 mL/L coconut water + 0.5 ppm IBA. A critical hormonal imbalance was identified at 150 mL/L coconut water + 0.5 ppm IBA, which delayed shoot emergence to 16.00 days and leaf emergence to 29.00 days. These findings demonstrate that optimal coconut water concentration depends on auxin type and developmental objective, with high concentrations favoring shoot multiplication when synthetic auxin is absent, while moderate concentrations combined with IBA optimize rooting and accelerate organogenesis. The superior performance of IBA over IAA for root development, coupled with the cost-effectiveness of coconut water as a natural cytokinin source, provides preliminary evidence for optimizing banana micropropagation protocols, although acclimatization trials and field performance evaluation are needed before commercial-scale adoption.