Abstract: To explore the effect of high-energy carbon ion beam on the stem section of potato tissue culture seedlings, this study took the stem section of potato variety “Xindaping” as the research material, four high-energy carbon ion beams with radiation dose gradient were selected. The plant lethal rate, rooting rate, lateral bud formation rate, morphological variation rate and leaf physiological and biochemical indicators were measured after irradiated. The semi-lethal radiation dose of the stem section of “Xindaping” tissue culture seedlings was determined. The results showed that there was a positive correlation between irradiation dose and lethal rate. The phenotypic changes of regenerated plants in stem segments of tissue culture seedlings were mainly as follows: asymmetric leaves, irregular leaf margins, variant elongation of stems, clustered leaves and adhesion of leaves. With the increase of irradiation dose, the activities of superoxide dismutase, peroxidase and catalase increased first and then decreased. The content of malondialdehyde increased first, then decreased, and last increased again. The semi-lethal irradiation dose of “Xindaping” was calculated by linear regression equation to be 20.37 Gy.

Key words: high-energy carbon ion beams, potato tissue cultured plantlets, irradiation, lethal dose at 50 percent, physiological characteristics