Abstract: Four dried seeds of mulberry（Morus L.） were irradiated by ⁶⁰Co-γ rays at 6 dose, the germination of the varieties were analyzed after irradiation. The results showed that irradiation mainly affects the germination potential and rooting ability of sage mulberry seeds. Analysis on the tolerance showed that Jisang No.3 was the strongest. Through the investigation of the germination and rooting of the seeds after irradiation, the lethal dose of mulberry seeds was 2 500 Gy.

Key words: mulberry（Morus L.）, seed, ⁶⁰Co-γ, tolerance, lethal dose