SOMATIC EMBRYOGENESIS AND PLANT-REGENERATION FROM SHOOT-TIP EXPLANTS IN PHOENIX-DACTYLIFERA L

For maximum avoidance of somaclonal variation risks, the commonly used medium for somatic embryogenesis in Phoenix dactylifera has been lowered in growth regulators and activated charcoal. When initially cultured on MS basal medium containing only 150 mg dm(-3) charcoal, 5 mg dm(-3) 2,4-dichlorophenoxyacetic acid (2,4-D) and 5 mg dm(-3) benzylaminopurine (BAP), 10 to 20 % of shoot-tip explants developed into embryogenic calli. The embryogenic potential has been maintained for over 24 months with no decline. In addition, this medium has been found to be more efficient than conventionaly one containing 3 g dm(-3) charcoal, 100 mg dm(-3) 2,4-D and 3 mg dm(-3) 2-isopentyladenosine (2IP). Plantlet regeneration was achieved when somatic embryos were subcultured to medium with 0.1 mg dm(-3) 2,4-D and 0.5 mg dm(-3) BAP or without growth regulators.