摘要：
为探索质子辐射玉米M1代的生物诱变效应,以5种不同剂量质子辐射诱变玉米种子,分别统计发芽率、成苗率、空秆率,并测定株高、穗位高、千粒质量以及光合速率等性状.结果表明,质子辐射诱变的玉米M1代在发芽、成苗、抽雄、吐丝、成熟等阶段有不同程度的变异出现,如出现叶片变形、雄性不育、花药和花丝变色、同位多穗以及成熟期提前等变异株;发芽率、成苗率均在84％以上,不同剂量质子辐射处理对其影响不大,但对空秆率的影响明显,40 Gy处理空秆率最高(20.93％).10 Gy处理玉米M1代千粒质量高达654 g,叶片光合速率高达23.48 μmol/(m2·s).RAPD分析发现,不同剂量质子辐射诱变的多态性比率为20.16％～32.26％.遗传相似度聚类分析表明,质子辐射诱变玉米群体在遗传相似系数0.69附近聚为2类.综上,质子辐射能够有效引起玉米M1代的生物诱变效应,空秆率、千粒质量以及光合速率等生物性状变异明显,且均有典型的马鞍形剂量效应出现.10 Gy质子辐射处理显著提高玉米千粒质量,结合群体生物性状认为,10 Gy为最优辐射剂量.RAPD以及聚类分析表明,质子辐射能够有效引起玉米基因组的变异,从而引起M1代的生物诱变效应.可见,质子辐射是玉米种质创新的一种有效手段.%In order to study the biological mutagenic effects of proton radiation on maize M1 generation,maize seeds were irradiated by five different doses of proton.The biological traits including germination rate,seedling rate,empty bar rate,plant height,ear position height,thousand kernel mass and photosynthetic rate were investigated,respectively.The results showed that proton radiation mutagenic maize M1 generation presented different degrees of mutation in germination,seedling,tasseling,silking and maturation stage such as leaf deformation,male sterility,anther or silk color changes,maturity stage in advance etc.Both the germination rate and seedling rate were all above 84％,and different doses of proton radiation treatments had little effect on them.However,the effect of proton radiation on empty bar rate was obvious,40 Gy treatment caused the empty bar rate achieving the maximum of 20.93％.With regard to maize M1 generation,the thousand kernel mass of 10 Gy treatment was up to 654 g,and the leaf photosynthetic rate was as high as 23.48 μmol/(m2 · s).RAPD analysis showed that the polymorphic rate in different doses of proton radiation ranged from 20.16％ to 32.26％.Genetic similarity clustering analysis showed that the proton radiation mutagenic maize group was clustered into two categories at the genetic similarity coefficient of 0.69 vicinity.In conclusion,proton radiation could effectively induce biological mutagenic effects on maize M1 generation.Several biological traits,such as empty bar rate,thousand kernel mass and photosynthetic rate,were significantly distinct and all appeared typical saddle-shape dose effects.10 Gy proton radiation treatment significantly increased the maize thousand kernel mass.Combined with the group biological traits,10 Gy was the optimal radiation dose.RAPD and cluster analysis demonstrated that proton radiation could effectively cause mutagenesis of maize genome and thus induce mutagenic effect of M1 generation.Proton radiation was an effective method for maize germplasm innovation.
