Novel and cost-effective approach for long-term in vitro culture producing genetically stable G9 banana plants

Banana holds significant economic importance as a cash crop across diverse regions around the globe. Among the many banana varieties, Grand Naine (G9) is particularly notable for its high commercial value owing to its exceptional fruit quality and adaptability for cultivation. The cultivation areas for G9 bananas are expanding each year, resulting in a substantial demand for high-quality planting material. Many laboratories globally are currently actively working on strategies to increase the production of G9 banana planting material through plant tissue culture methodologies. Herein, we report an innovative and efficient in vitro propagation method for G9 banana using various cytokinins including metaTopolin alone and in combination with auxins. This protocol is useful for raising in vitro banana plants with a high rate of shoot multiplication in a liquid culture system while ensuring genetic stability during their long-term cultures. The genetic fidelity of in vitro raised plants vis-à-vis the field-grown mother plants was evaluated using RAPD, ISSR, and SCoT markers. Virus indexing of the micropropagated plants was also carried out for BBTV and BSV virus. Overall, the developed protocol offers a valuable means for the production of large-scale, disease-free plants year-round, catering to the demands of farmers cost-effectively.