用3种不同剂量60Co-γ射线辐射处理2个玉米自交系种子,对其诱变后代M1生物学效应及其M3株系主要性状的变异进行了分析.结果表明:①2个玉米自交系M1植株均受到明显的抑制及辐射损伤,具体表现在,株高和穗位高降低,叶面积减小,并且这种抑制损伤效应随着辐射剂量的增加而增大；它们的M1雄穗长和雄穗分技数均降低；低剂量处理就能引起RO8的穗长和48-2的穗行数在M1代产生较大变化.②诱变后代M3株系各性状出现不同程度的正向突变和负向突变,其中株高、穗位高及叶面积平均值与对照有显著差异的M3株系频率高于主要雄穗及果穗性状,说明这些性状的诱变效果更好；诱变后代各性状的变异幅度和变异系数增大,表明辐射诱变能扩大玉米主要性状的变异谱,拓宽选择范围.此外,在48-2的M3代还获得了2个籽粒颜色发生突变的株系和2个雄性不育突变株系.%Seeds of two maize inbred lines R08 and 48-2 were irradiated by ""Co'-y ray at 3 different doses and the biological effects of muta-genic progenies M, as well as the variation of the main characters of corresponding M3 lines were analyzed. The results showed that: ( I ) the M, plants of two maize inbred lines suffered remarkable suppression and radiation damage, including the plant height, ear height, and leaf area restrained at different degrees, and the suppression effect increased with radiation dose. Both branch length and branch tassel number of M, decreased; Low dose of irradiation could cause big change on ear length of R08 and ear rows number of 48-2 in M,. ( jj ) The main characters of M3 lines exhibited two-way segregation to varied degree. The percentages of M3 lines with average values of plant height, ear height and leaf area were larger than that of CK significantly, higher than that of the main tassel and ear characteristics, this phenomenon indicated that the mutation effects of these characteristics of the former were better than that of the latter; the increase of the variation range and coefficient of characters in the mutagenic progenies, indicated that irradiation could enlarge the variation speetrufn of major characters in maize, and thus broaden the scope of selection. Additionally, two mutant lines with kernel color changed and two mutant lines of sterile male were obtained in M3 generation of 48-2.
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