Effect of progesterone as a precursor of the cardiac glycosides and explant type on callus formation and its glycosidal content in Nerium oleander

In vitro experiment has been conducted to evaluate the effect of different concentrations of progesterone and explants type on glycosidal content in Nerium oleander. Obtained callus of leaves and shoot tips was cultured on ¾ MS medium supported by 2 mg/l. kinetin combined with 2 mg/l. 2,4-D, different levels of (0, 0.2, 0.5, 1 and 1.5 mg/l.) progesterone, 6 g./l. agar, and 30 g/l. sucrose for 6 weeks. Our results revealed that the highest fresh and dry weights of callus were achieved from the medium contained 0.5 mg/l. progesterone as for shoot-tips and leaves calli which averaged 3.145 and 0.300 g. However, this concentration gave low percentage of oleandrin (0.7%) comparing with the percentage of 0.8% which achieved from the medium supported with the high concentration of progesterone (1 mg/l.), it gave the highest value of oleandrin quantity either in callus derived from shoot-tip or leaf (1.96 and 2.24 mg.).