不同剂量重离子辐照玉米自交系的生物学效应比较

用12C6+和 36Ar18+离子束分别辐照玉米自交系干种子和浸泡种子， 研究了M1—M3代重离子束辐照的生物学效应。 结果表明: 种子发芽势和发芽率随辐照剂量的增加而下降， 不同生理状态的种子对重离子辐照的敏感性也不同。 一般12C6+ 离子辐照干种子的适宜剂量为20—25 Gy； M1代叶型发生明显的变化， M2代植株在株高、穗位、单株穗数、雄穗花药颜色、粒质、穗行数、粒重和抗性等方面均发生了变化， 并产生了许多有益的变异，包括株高和穗位降低、同位多穗、穗行数和粒重增加、粒质由粉质变为硬粒以及抗锈病和红叶病的植株等， 有益突变的频率达7.0％—17.9％；在M3代出现能够稳定遗传的，并且光合效率增加的有益突变株。由此可见，重离子束辐照是玉米种质改良的一种高效手段。 In order to study biological effects of heavy ion irradiation on maize inbred lines， the agronomic traits and photosynthetic rates were investigated from M1 to M3 of maize seeds irradiated with 12C6+ and 36Ar18+ ions．The results showed that the germination rate and planting percent of maize seeds irradiated were decrease as dosage increasing of heavy ion irradiation. Different physiological status of seeds had disparate sensibility to heavy-ion irradiation and the suitable dosage of 12C6+ ion irradiation was 20—25 Gy for dry maize seeds. The leaf type of the plant happened visible changes in M1 generation. The plant height， spike position， spike number per plant， anther color of staminate，grain texture，spike row，grain weight and resistance had changes in M2 generation. Among them occurred some beneficial mutations that include degrading of plant height and spike position height， multi spike at same position in the plant， increasing of pike row and grain change of grain texture from powder seed to hard seed，resistance to rust disease and red leaf disease and so on. The frequency of beneficial mutation was 7.0％—17.9％. Those beneficial mutations could be stably inherited and mutant plants with high photosynthetic efficiency emerged in M3 generation. The study above showed that heavy ion irradiation is a high performance means for improvement germplasm of maize.

Study of Biological Effects of Heavy Ion Ieeadiation on Maize Lines

In order to study biological effects of heavy ion irradiation on maize inbred lines， the agronomic traits and photosynthetic rates were investigated from M1 to M3 of maize seeds irradiated with 12C6+ and 36Ar18+ ions．The results showed that the germination rate and planting percent of maize seeds irradiated were decrease as dosage increasing of heavy ion irradiation. Different physiological status of seeds had disparate sensibility to heavy-ion irradiation and the suitable dosage of 12C6+ ion irradiation was 20—25 Gy for dry maize seeds. The leaf type of the plant happened visible changes in M1 generation. The plant height， spike position， spike number per plant， anther color of staminate，grain texture，spike row，grain weight and resistance had changes in M2 generation. Among them occurred some beneficial mutations that include degrading of plant height and spike position height， multi spike at same position in the plant， increasing of pike row and grain change of grain texture from powder seed to hard seed，resistance to rust disease and red leaf disease and so on. The frequency of beneficial mutation was 7.0％—17.9％. Those beneficial mutations could be stably inherited and mutant plants with high photosynthetic efficiency emerged in M3 generation. The study above showed that heavy ion irradiation is a high performance means for improvement germplasm of maize.