摘要：A method for the micropropagation of Portulaca grandiflora Hook is described to understand the in vitro behaviour of nodal explants in cytokinin-rich medium. Aseptic nodal explants were cultivated on Murashige and Skoog's medium containing different concentrations and combinations of 6-benzylaminopurine (BAP) and 6-furfurylaminopurine (kinetin, KIN). The nodal explants of mature plant can be stimulated to undergo multiple shoot formation on the medium supplemented with BAP and KIN. Direct organogenesis without callus formation from the nodal explants was observed on medium supplemented with cytokinins. Using BAP (2 to 10 μM) alone had a significant effect on the formation of multiple shoots, which were stout and robust. Similar concentrations of KIN (2 to 10 μM) showed a weaker response. It was observed that when the optimum concentration of KIN (8 μM) was supplemented with low concentration of BAP (2 μM or 4 μM) there was a synergistic effect on the explant in terms of shoot regeneration. Single shoots were rooted on a half strength medium with 2 μM indole-3-butyric acid
