[en] The seeds of three cultivars of tall fescue were treated by ⁶⁰Co γ-rays, seeds germination, the activity of SOD, POD and PPO during seeds germination were analyzed. Results showed that the seed germination was promoted under 50 Gy irradiation, but were inhibited in higher dose irradiation. With dose increasing, the effect of inhibition was enhanced; the activity of three enzymes was increased at lower doses and declined with dose increasing. The dose of 150 Gy was recommended as suitable dosage for the tall fescue irradiation mutagenesis. (authors)