Galun, E., The Weizmann Institute of Science, Rehovot, Israel

Protoplasts have been isolated from non-differentiating ovular callus of Citrus sinensis and cultured in solid medium. Optimal plating density for cell division and colony formation was in the range of 105 cells per ml. Colony formation took place in about 4-9% of the protoplasts. Survival of protoplasts was reduced to about one half after exposure to 0.3% ethyl methanesulphonate (EMS) for one hour. Exposure of protoplasts to X-ray radiation resulted in half-survival at about 3400 R. Embryoid regeneration was promoted in callus from X-irradiated protoplasts. © 1975.