用60_Coγ射线15,25和35krad分别处理感稻瘟病水稻品种(系)浙粳66和R_8617,经M_2代稻瘟病区自然诱发筛选,并经后代人工接种鉴定,在M_2代中分别选到抗病变异单株30、34和36株。不同剂量处理后的变异率分别为0.016％、0.019％和0.316％。经M_4代进一步人工接种鉴定,除个别株系抗性较差外,多数变异产生的抗性是可遗传的。用不同稻瘟病生理小种接种鉴定发现,不同抗病突变系的抗谱有较大的差异。 Rice cultivars (lines) Zhejing 66 and R_8617 were treated with 60_Coγ-rays at 15, 25 and 35krad, respectively. After M_2 generation of blast areas were naturally induced and screened, and were identified by offspring artificial inoculation, Variant plants 30, 34 and 36 strains. The variation rates after different doses were 0.016%, 0.019% and 0.316% respectively. M_4 generation by further artificial identification of inoculation, in addition to individual lines less resistant, the majority of resistance mutations produced are heritable. Inoculation identification of different rice blast physiological races showed that the resistance spectrum of different disease-resistant mutants was quite different.