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

Present study reports meta-Topolin (mT)-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, mT, thidiazuron and zeatin in variable doses (0.5-1.5 mg L-1) were supple-mented in the basal Murashige and Skoog (MS) medium and comparative growth performance of the inocu-lated shoot tip explants were studied. Maximum number of de novo shoots (-14) and leaves (-40) were obtained in 1.5 mg L-1 mT. 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 transpi-ration activities accompanied by significant levels of photosynthetic pigments in plantlets during acclimati-zation. 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 exhib-ited ploidy as well as chromosomal stability, and monomorphic banding patterns confirmed no polymor-phism 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.(c) 2022 SAAB. Published by Elsevier B.V. All rights reserved.

Automated summary

This study reports the in vitro mass propagation of Gerbera jamesonii Bolus ex Hooker f., a highly demanded cut-flower in the floriculture industry, induced by meta-Topolin (mT). The subsequent acclimatization process and cyto-genetic fidelity assessment of the plantlets were also carried out. Different cytokinins and cytokinin-like plant growth regulators were supplemented in the basal Murashige and Skoog (MS) medium, and the growth performance of the shoot tip explants was compared. The developed protocol for large-scale production of true-to-type planting materials of gerbera is of great commercial importance.