Regeneration of plants from callus tissue of okra ( Abelmoschus esculentus)

Abstract

Hypocotyl and cotyledonary axil explants of aseptically grown okra ( Abelmoschus esculentus) seedlings were induced to form callus when cultured on Murashige and Skoog's (MS) basal medium supplemented with cytokinins or auxin-cytokinin combinations. The presence of kinetin (KN) or zeatin (Z) in the induction medium stimulated callus formation on hypocotyl explants. The cotyledonary axil explants failed to yield callus when cultured on media containing KN or Z or the combination of either of these two cytokinins with indoleacetic acid (IAA) or naphthaleneacetic acid (NAA). Rapid callus induction resulted from all explants cultured on MS medium supplemented with benzyladenine (BA) (1.0 mg·1 −1). The hypocotyl-derived callus remained non-organogenic, when subcultured on fresh BA-supplemented MS medium, whereas, cotyledonary-axil-derived callus produced number of buds. The transfer of the organogenic calli to BA-enriched MS media containing various concentrations of silver nitrate (0–40 mg·1 −1) stimulated multiple shoot development within 2–3 weeks. The presence of 10 and 20 mg·1 −1 of silver nitrate significantly increased the number of calli producing multiple shoots when myo-inositol and casein hydrolysate were omitted from the growth medium. Roots developed quickly when regenerated shoots were subcultured on MS medium containing BA (1.0 mg·1 −1) and NAA (1.0 mg·1 −1. The plantlets, on transfer to soil, grew normally.