The effect of the elicitor – a solution of a homogenate and killed cells of Rhodotorula rubra in three different concentrations on the production of flavonoids in a callus and suspension culture of Ononis arvensis L. was tested. The elicitor was in contact with the culture for 24; 48 and 168 hours. It follows from the obtained results that in the case of both the homogenate and the solution of the cells of Rhodotorula rubra there occurred a significant increase in the production of flavonoids with the use of the concentration c3 after 48 hours’ elicitation. However, even after 24 hours of elicitation the content of flavonoids was increased.

        Key words: Ononis arvensis – flavonoids – elicitor – Rhodotorula rubra