The influence of plant growth regulators on callus induction from hypocotyls of cucumber (Cucumis sativus L.)

The purpose of this study was to develop an efficient protocol for callus induction of cucumber. Hypocotyl explants of cucumber (Cucumis sativus L. cv. Sultan) were cultured on Murashige and Skoog (MS) media supplemented with individual treatments of different auxins (2,4-dichloro-phenoxyacetic acid (2,4-D), indole -3acetic acid (IAA), α naphthalene acetic acid (NAA)) or cytokinins (benzyl adenine (BA) and kinetin (Kn)). The result of this study showed that callus induction frequency, callus growth rate and nature of callus were significantly affected by type and concentration of the plant growth regulators and were greatly higher when incorporating auxins in the medium compared to cytokinins. The maximum callus induction frequencies was observed on MS media with 2,4-D or NAA. NAA at 1.0 mg/L resulted in the best callus growth index. Incorporating cytokinins (BA or Kn) in the callus induction media promoted slow callus growth and low quality callus compared to that produced on media containing auxins. Callus induced on media containing NAA or IAA was friable and yellow in color.