Plantlet regeneration of Cucumis melo L. Glamour cv. using different types of cytokinin and explants

Abstract

Plantlets or clones’ regeneration in Cucurbitaceae species can be performed in vitro by applying the tissue culture techniques. Hypocotyls, cotyledons, leaves, cotyledonary nodes and petioles can be used as the explants or starting materials to initiate the regeneration under laboratory condition. BAP (Benzyl aminopurine) and TDZ (Thidiazuron) were among the well-known cytokinin used in tissue culture as plant hormones to regulate the plant growth in vitro. The effectiveness of BAP and TDZ was investigated in this study to determine the effect of different types of cytokinin hormone on C. melo explants since both hormones might show differences in their activity towards C. melo explants. This study found that BAP was superior at all used concentrations compared to TDZ during most of the growing stage of the explants (cotyledons and hypocotyls). Based on this finding, the experiment was repeated by using different types of explants which were nodal explants, petioles and young shoots along with cotyledons and hypocotyls, by using BAP that showed excellent plantlet regeneration. Cotyledon and nodal explants successfully regenerated plantlets with excellent height and significant number of shoots compared to the rest of the explants. The plantlets from cotyledons and nodal explants were regenerated via direct regeneration without any formation of callus. The direct shoot regeneration was the preferred method for mass production via tissue culture because the chances of somaclonal variation is low. Contrarily, the hypocotyls, petioles and shoot tips mostly developed callus and only several treatments formed very small plantlets.