SOMATIC EMBRYOGENESIS AND PLANT-REGENERATION OF NERIUM OLEANDER

Leaf explants of Nerium oleander L. produced masses of callus when both an auxin and a cytokinin were included in the medium. Leaves cultured on the B5 medium of Gamborg et al. supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D; 9.05 mu M) plus benzyladenine (BA; 4.4 mu M) produced callus and profuse rhizogenesis was observed from callus developed from older leaves. On Murashige & Skoog medium (MS) with the same concentration of 2,4-D and BA, explants from young and mature leaves produced callus, but only that from young leaves was embryogenically competent. Globular somatic embryos were obtained when embryogenic cells were cultured on MS medium without growth regulators. Both normal and anomalous development of embryos occurred in either liquid or gelled medium. Plantlets were produced faster when mature embryos were cultured on either solid medium or placed on Sorbarod plugs soaked with this same medium but with 1% sucrose. Plantlets with three nodes were transferred to pots and acclimatized in a growth chamber and afterwards transferred to garden beds.