Regeneration of okra (Abelmoschus esculentus L.) via apical shoot culture system
The present study was undertaken to evaluate the most suitable concentration of growth regulators for regeneration of okra (Abelmoschus esculentus L. Monech) via apical shoot culture system. The study of apical shoot culture system was found effective for regeneration of apical shoots. The okra (A. esculentus L. Monech) N-550 line evolved at R&D, Nirmal Seeds Pvt. Ltd., was used as basic material for experiment of regeneration using different auxin and cytokinin hormone combination. Nine to ten days old germinating seedlings were used for isolation of shoot tip explants, isolated shoot tips were cultured on regeneration medium, Murashige and Skoog (MS) medium supplemented with alone indole-3-butyric acid (IBA) (0.25, 0.5, 1.00, 1.5, 2.0 and 2.5 mg/L) and IBA 1.0 mg/L with naphthalene acetic acid (NAA) (0.25, 0.5, 1.00, 1.5, 2.0 and 2.5 mg/L). After regeneration, cultures were inoculated on elongation medium containing MS medium supplemented with kinetin (0.25, 0.5, 1.00, 1.5, 2.0 and 2.5 mg/L). Elongated shoots transferred to rooting medium containing MS medium supplemented with indole-3-butyric acid (IAA) (0.25, 0.5, 1.00, 1.5, 2.0 and 2.5 mg/L). Combination of 1.0 mg/L IBA and 0.5 mg/L NAA were found to be most effective for plant regeneration from apical shoot. Best shoot elongation observed in MS medium supplemented with kinetin 0.5 mg/L. Elongated shoots rooted most effectively in MS medium containing 0.5 mg/L IAA and 1.0 g activated charcoal. The success of apical shoot culture system of okra was encouraged by acclimatization of the plantlets in the field conditions.
Key words: Abelmoschus esculentus, apical shoot, auxins, cytokinines, regeneration