2004 Volume 73 Issue 4 Pages 340-342
The plant regeneration process in onion (Allium cepa L.) calli was investigated histologically. In the plant regeneration process from the calli, embryo-like structures formed on the surface of the calli, that developed into plantlets. Several developmental stages of these embryo-like structures were recorded histologically. These embryo-like structures progressed from a globular embryo to a bipolar embryonic shoot and root apices which were connected with vascular bundles. On the other hand, the shoot-like structures, having abnormal, hyperhydrated appearance, seemingly formed via organogenesis. However, these shoot-like structures did not develop into shoots or plantlets. Therefore, it was concluded that the regeneration of the plantlets occurred through somatic embryogenesis.