The paper tested the effect of iodoacetic acid in four different concentrations on the production of flavonoids in the callus and suspension culture of Ononis arvensis L. The elicitor was in contact with the culture for a period of 6; 24; 47; 72, and 168 hours. The obtained results show a statistically significant increase in the content of flavonoids in the suspension culture in comparison with the control in the use of all tested concentrations of the elicitor after 6; 24; 48, and 72 hours of elicitation. The maximal increase by 586 % in the production of flavonoids in the suspension culture took place with the use of iodoacetic acid in a concentration of 1mg/l. In the callus culture, the maximal increase in the formation of flavonoids occurred with the use iodoacetic acid in a concentration of 10 mg/l after 24 hours of elicitation, the content of flavonoids being increased by 529 % in comparison with the control.

        Key words: Ononis arvensis – flavonoids – elicitation – iodoacetic