The effect of the elicitor, killed cells of Pseudomonas aeruginosa, on the production of flavonoids by a callus and a suspension culture of Ononis arvensis L. was examined. The tested elicitor influenced the flavonoid production both in the callus and suspension culture. An increased content of flavonoids in the callus culture was observed with the use of the elicitor in concentrations I and II (5.81.10 -2 and 5.81.10 -4 g/l). The maximal production took place after a seven-day elicitation with concentration II. This production was higher by 83 % as compared with the control. In suspension cultures an increased production was observed in concentrations I and III (5.81.10 -2 and 5.81.10 6 g/l). The maximal content of flavonoids was measured after 48-hour elicitation with concentration I. In comparison with the control the increase in the flavonoid content was higher by up to 125 %.

        Key words: Ononis arvensis – flavonoids – elicitation – Pseudomonas aeruginosa