Study of Biological Effects of Heavy Ion Irradiation on Maize Inbred Lines

Key words: 
• heavy ion irradiation /
• dosage /
• biological effect /
• mutation /
• maize

Abstract: 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.