A principal precondition for successful elicitation used to increase the production of secondary metabolities is, among other, finding a suitable elicitor, its concentration and the optimal period of time of the action of the elicitor on the plant culture in vitro, which was the aim of the present paper. The effect was examined of a 6; 24; 48 and 168 hour action of the suspension solution of the dead cells of Pseudomonas aeruginosa (in five concentrations) on the production of anthracene derivatives in the callus and suspension culture of Rheum palmatum cultivated on a Murashige-Skoog medium with an addition of 10 mg/l of a-naphthylacetic acid. The maximal content of anthracene derivatives found by a photometric determination according to PhBs 4 was demonstrated in the callus culture (1.03 %) after 24 hour action of the elicitor (1.7 mg/flask) and in the suspension culture (0.94 %) after 48 hour action of the elicitor (0.0017 mg/flask).

        Key words: Rheum palmatum L. – plant culture in vitro – anthracene derivatives – biotic elicitor – Pseudomonas aeruginosa