Abstract: The seeds of two flue-cured tobacco cultivars, Yunyan 87 and Hongda, were irradiated by the different irradiation doses of ⁶⁰Coγ-ray, The effect of irradiation treatment on seed vitality of Yunyan 87 and Hongda was studied. The results showed that, in the irradiation treatment of 10-300 Gy at 25℃, the seed vitality for two cultivars were both promoted, among which, 10 Gy was the optimal irradiation dose for two cultivars; The seed vitality for two cultivars were inhibited when treated with dose more than 300 Gy. The results also showed that the seed vitality of Yunyan 87 was better than Hongda, indicating Yunyan 87 had higher adaptability under irradiation treatment.

Key words: ⁶⁰Coγ-ray, Yunyan 87, Hongda, seed vitality