Immature zygotic embryos from a self-pollinated sunflower line 147 R (Helianthus annuus L.) were used for donor material to induce direct organo genesis. A portion of the isolated immature embryos were treated with gamma radiation (137Cs) at a dose of 5 Gy before plating. The range of the spontane ously induced somaclonal variation among the obtained regenerants was investigated and compared with that of the variants induced through irradiation. The genetic changes occurring spontaneously during the regeneration procedure included seventeen morphological and biochemical characters. The most significant changes were observed for the characters of plant height, stem diameter, head diameter, length of branches, oil content in seed (%) and 1000 seed weight. The researches showed that the somaclonal (R9) and the radiationinduced (M9R9) variants revealed similar spectra of morphological and biochemical modifications, thought with different frequency.