Standardization of Meta-Topolin Concentration for Maximizing In vitro Proliferation in Commercial Banana Cultivars of Andhra Pradesh, India

Cytokinins are associated with cell division, cell growth, and differentiation, are the most common plant growth regulators used in micropropagation. Aromatic cytokinin, meta-topolin (mT), and its derivatives have been demonstrated as alternative cytokinins in the in vitro multiplication of various plants. Different banana cultivars differ in in vitro shoot proliferation due to the difference in endogenous growth regulator content among them. A study was conducted to figure out the effect of different concentrations of meta-topolin on in vitro shoot proliferation of banana cultivars like Karpura chakkera keli (AAB), Mortoman (AAB), and Kovvur Bontha (ABB). In vitro shoot proliferation was initiated from the first subculture (C1) itself at 1.5 ppm mT concentration in Mortoman, Kovvur Bontha, and from the second subculture (C2) at 1.0 ppm mT concentration in Kovvur Bontha. Whereas, at all other remaining concentrations, shoot proliferation of different cultivars was initiated from the third subculture (C3) only. At the end of the sixth subculture (C6), the maximum number of shoots per explant (82.70) was recorded in the Kovvur Bontha cultivar at 1.5 ppm mT concentration. Among the cultivars, the Kovvur Bontha cultivar responded better to the meta-topolin for shoot proliferation than Karpura chakkera keli (AAB) and Mortoman (AAB).