Accelerated mono-phasic in vitro mass production of banana propagules and their morpho-cyto-genetic stability assessment

A unique one-step in vitro propagation protocol via concurrent shoot-root development was established in banana cv. Grand Nain. 6-benzyladenine, kinetin, meta-Topolin, thidiazuron (TDZ), and zeatin (0.5—1.5 mg L ⁻ ¹) individually supplemented in Murashige and Skoog medium were tested for multiple shoot-root regeneration from shoot tip explants. The earliest fresh shoot (∼7 days) and root (∼5 days) initiation, highest number of shoots (∼21) and roots (∼16) with maximum root elongation (16.5 cm) were recorded in 0.5 mg L ⁻ ¹ TDZ. For all intents and purposes, TDZ (0.5 mg L ⁻ ¹) was recorded to be the optimum formulation in terms of the highest simultaneous shoot and root formation that was corroborated further by matrix plot analysis. On the other hand, network plot analysis and principal component analysis illustrated the association between plant growth regulators based on their effect on growth attributes under study. Histological studies on shoots, roots, and leaves revealed a consistent growth and development of plantlets under in vitro condition. Cent percent plantlets were survived during acclimatization, and performed best in cocopeat in comparison to other substrata (vermiculite, perlite, vermicompost-soil, soil-sand, and sand only). The cytology-, flow cytometry- and ISSR primer-assisted fidelity assessments of the in vitro-regenerants exhibited numerical chromosomal as well as ploidy stability and monomorphic banding patterns without any polymorphism within the in vitro-regeneranted plantlets and with their mother plant. Based on the comprehensive information developed in this study, this protocol should be of immense importance to facilitate single-step large-scale production of true-to-type planting materials and to explore the possible comparative physico-chemical roles of the plant growth regulators used in this study.