12C6+重离子束辐照玉米后代的生物学效应

Biological Effects of Offspring of Maize Irradiated by 12C6+ Heavy Ion Beam

为给玉米种质创新及品种改良创制优异的资源材料,采用不同剂量0(对照)、30、60、90、120 Gy的12C6+重离子束辐照自育骨干玉米自交系LY8405干种子,并对各剂量辐照后代植株的生物学效应进行详细的对比分析。结果表明,随着辐照剂量的增加,自交系LY8405 M1种子发芽率、株高、穗位高和花粉活力均低于对照组,相同剂量辐照的M2生理损伤检测指标较M1有较大程度的恢复,但仍显著低于对照组,而90和120 Gy剂量辐照后的M1、M2种子发芽率、株高和穗位高均与对照组表现出极显著差异;辐照剂量为30 Gy时,在M2、M3植株变异表型筛选中,创制出了多种农艺性状表型变异突变体,说明30 Gy是对自交系LY8405的生物学效应最为明显的辐照剂量,60 Gy影响效应次之,同时60 Gy是辐照半致死阈值;M2和M3突变类型包括植株矮化、穗位高度降低,叶片皱缩、叶色黄化、白化、花叶,穗型变大、变长,穗轴颜色由白变红,籽粒颜色由黄变为酒红色,粒型由马齿型变为硬粒型。生物学效应表明,30~40 Gy辐照剂量是0~120 Gy范围内重离子辐照选育玉米自交系LY8405的适宜剂量。本研究结果为不同玉米自交系创制新的种质资源提供了方法,更为玉米选育新品种提供了稳定的遗传材料。

In order to create excellent planting materials for maize germplasm innovation and variety improvement,dry maize seeds of inbred line LY8405 were irradiated by12C6+heavy ion beams under different doses of 0(control),30,60,90,120 Gy and the biological effects of progeny plants after irradiation were compared and analyzed in detail.The analysis results showed that with the increase of irradiation dose,the germination rate,plant height,ear position height and pollen vitality of LY8405 in M1 generation were significantly decreased compared to the control.The physiological damage detection index of M2 offspring irradiated with the same dose was some recovered,but was still significantly lower than that of the control.The germination rate,plant height and ear position height of M1 and M2 irradiated by 90 Gy and 120 Gy showed extremely significant differences from that of the control.When the radiation dose was 30 Gy,a variety of agronomic phenotype mutants were screened in M2 and M3,indicating that the biological effects by 30 Gy was the most obvious for inbred line LY8405,followed by 60 Gy.At the same time,60 Gy was the threshod of semi-lethal dose.The mutation types of M2 and M3 including dwarf,lower ear position height,wrinkled leaf blade,yellowish leaf,white and mottled leaves,larger and longer spike,red cob instead of white,wine red grain color from yellow,and grain shape changing from dent corn to flint corn.Biological studies showed that 30-40 Gy is the suitable irradiation dosage for breeding maize inbred LY8405 with 12C6+heavy ion irradiation within the scope of 0-120 Gy.This study will provide a method and dose reference for the creation of new germplasm resources of different maize inbred lines,and more important,it also provide some stable genetic materials for the selection and breed of new maize varieties.