meta-Topolin-induced mass propagation, acclimatization and cyto-genetic fidelity assessment of gerbera (Gerbera jamesonii Bolus ex Hooker f.).

• Present study report exclusive influence of meta -Topolin (m T) on in vitro regeneration of gerbera. • 100% regenerated plantlets were acclimatized in sand, soil, cow urine and tea leaves extract followed by sand-soil substrata. • Micromorphological studies on shoot, root and leaf revealed systematic plant growth. • Leaf gas exchange analysis revealed photosynthetic and transpiration activities accompanied by significant levels of photosynthetic pigments. • Clonal fidelity was ensured via cytology, flow cytometry, ISSR and SCoT markers. Present study reports meta -Topolin (m T)-induced in vitro mass propagation of Gerbera jamesonii Bolus ex Hooker f. (a cut-flower with high demand in the floriculture industry), subsequent acclimatization, and cyto-genetic fidelity assessment of the plantlets. Different cytokinins (and cytokinin-like plant growth regulators) i.e., 6-benzyladenine, kinetin, m T, thidiazuron and zeatin in variable doses (0.5–1.5 mg L−1) were supplemented in the basal Murashige and Skoog (MS) medium and comparative growth performance of the inoculated shoot tip explants were studied. Maximum number of de novo shoots (∼14) and leaves (∼40) were obtained in 1.5 mg L−1 m T. Earliest (∼9 days) root induction from shoot with maximum number (∼8) and length (∼6 cm) of roots were recorded in MS medium fortified with 1.5 mg L−1 indole-3-acetic acid. All the micropropagated plantlets (100%) were acclimatized in sand, soil, cow urine and tea leaves extract (1:1:1:1; v v −1) followed by sand-soil (1:1; v v −1) mixture. Histological studies on shoots, roots, and leaves along with leaf gas exchange analysis revealed a stimulated growth, cellular development, photosynthetic and transpiration activities accompanied by significant levels of photosynthetic pigments in plantlets during acclimatization. The flow cytometry-, cytology-, as well as Start Codon Targeted (SCoT) Polymorphism and inter simple sequence repeats (ISSR) marker-assisted fidelity assessments of the micropropagated plantlets exhibited ploidy as well as chromosomal stability, and monomorphic banding patterns confirmed no polymorphism within the plantlets and with their mother plant. The developed protocol should be of immense commercial importance to facilitate large-scale production of true-to-type planting materials of gerbera. [ABSTRACT FROM AUTHOR]