252 Cf 裂变中子辐照玉米种子生物学效应初步研究

摘要

To study the biological effects and rules of neutron irradiation on maize seeds.Maize inbred lines LY8405 and PH6WC were irradiated by using252 Cf fission neutron source,screening suitable neutron irradiation dose and creating mutants for gene mapping,cloning and its functional analysis.The results showed that the germination rate of LY8405 was descended after neutron irradiation at low absorbed doses(0.36 -4.1 9 Gy),however that of PH6WC was increased.With irradiation dose increasing,the rates of distortion,mutation and total genetic variation of the two materials M1 were all added.LY8405 showed the most sensitively biological effects at 4.1 9 Gy irradiation dose,the rates of distortion,mutation and total genetic variation were 27.8%,38.9% and 66.7%,respectively;PH6WC showed the most sensitive effect at 2.48 Gy irradiation dose,the rates of distortion,mutation and total ge-netic variation were 7.1 %,1 4.3% and 21 .4%,respectively.Besides,the coefficient of variation of the agronomic characters,including plant height,ear position,leaf number,tassel branch number,spike length,ear diameter,kernel rows per spike and axis width,were all raised with the rising of irradiation dose.The paper indicated that the sensi- tive degree of maize genotype was different to fast neutron radiation dose;initially considered that 2.00 -4.1 9 Gy was suitable dose of irradiate maize seed using252 Cf fission neutron source.%为了探索快中子辐照玉米种子的生物学效应，筛选适宜的中子辐照剂量，以获得基因定位、克隆及其功能分析的突变体材料，采用252 Cf 裂变中子源对玉米自交系 LY8405和 PH6WC 种子进行辐照，结果表明，低吸收剂量（0．36～4．19 Gy）的中子辐照玉米干种子后，对自交系 LY8405的出苗率有一定的抑制作用，对自交系 PH6WC 的出苗率有一定的促进作用；2份材料 M1畸变率、变异率、遗传总变异率，随着辐照剂量的增加有逐步升高的趋势，其中辐照剂量为4．19 Gy 时对 LY8405最为有效，畸变率、变异率、遗传总变异率分别为27．8％，38．9％，66．7％；辐照剂量为2．48 Gy时对 PH6WC 最为有效，畸变率、变异率、遗传总变异率分别为7．1％，14．3％，21．4％；M2株高、穗位、叶片数、雄穗分枝数、穗长、穗粗、穗行数、轴粗等主要农艺性状变异随辐照剂量的增加，其变异系数也随之增加。研究表明，不同基因型玉米种子对快中子辐射剂量的敏感性不同，初步认为2．00～4．19 Gy 的辐照剂量是玉米252 Cf 裂变中子辐照处理的适宜剂量。