[en] Seeds of a hybrid corn with normal genotype and of opaque-2 genotype were irradiated at 0 - 200 Gy (10 mGy= 1 rad) of ⁶⁰Co gamma irradiation. The free and bound amino acid levels of these two genotypes were compared from shoots of 10 days old seedlings. In control seedlings totals of free and bound amino acid levels were significantly higher in opaque-2 genotype in comparison with the normal genotype. Following exposure, the free amino acid levels of the normal genotype did not show any significant radiation dependent increase or decrease, while in opaque-2 genotype the total levels of free amino acids showed a significant increase at all exposures. In bound amino acids, on the other hand, significant increase in total levels was observed in normal genotype at all exposures, while in opaque-2 genotype decreases were observed at all exposures, except for 100 Gy. Based on these observations opaque-2 genotype appears to be more radiosensitive than the normal maize. The results are discussed in relation to the genetic differences in the mechanism of protein biosynthesis of the two genotypes. (author)