Effects of different cytokinins on the micropropagation of Petunia hybrida L.

Petunia hybrida L. has beautiful flowers with vibrant and diverse colors. This study evaluated the effects of three cytokinins - kinetin, benzyl adenine (BA), and meta-topolin (mT) - on in vitro shoot multiplication of petunia. Nodal explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of cytokinins. After three weeks, all treatments induced shoot formation. The highest shoot proliferation (22 shoots per explant) was obtained with 1.0 mg/L mT, significantly higher than BA (8.25 shoots/explant) and kinetin (6.62 shoots/explant). For rooting, half-strength MS medium without auxin effectively promoted root development. Plantlet survival depended on the cytokinin used during shoot multiplication. Shoots cultured with 1.0 mg/L mT and rooted without auxin had the highest survival rate (84.62%). These findings suggest that mT is an effective cytokinin for micropropagation of petunia, enhancing the shoot multiplication rate and improving both the quality and survival rate of the plantlets