Application of Epr Spectrometry for Identifying the Irradiation of Wheat Seeds with Low-Energy Electrons

This study aimed to investigate the applicability of electron paramagnetic resonance (EPR) spectrometry for detecting the radiation treatment of spring wheat seeds using low-energy electrons. Seeds of the Iren variety (2023 crop, first reproduction) were irradiated one year after harvesting using electrons at energies of 100 and 120 keV over a dose range of 1.5 kGy (in 1 kGy increments); the dose rate was 100 Gy/imp. Non-irradiated seeds served as the control. After irradiation, the seeds were stored in the dark at room temperature and relative humidity below 60%. EPR spectrometry was performed 14 and 28 days and 3 and 6 months after irradiation. The dependence of the EPR signal on the irradiation dose and its attenuation over time have been studied. An increase in EPR signal intensity with increasing dose has been recorded. The difference in signal amplitude between the samples irradiated at 100 and 120 keV reached 8–55% after 14 days and 12–62% after 28 days, depending on the dose (p ≤ 0.05). During the first 14–28 days, the signal intensity decreased by 16–38 (100 keV) and 16–32% (120 keV), depending on the dose. After 3 months, the intensity decreased by 5–25 (100 keV) and 5–47% (120 keV) compared to the data for the 28th day. After 6 months, the signal intensity decreased by 26–33 (100 keV) and 26–41% (120 keV) compared to the 3-month data. The g-factor (at the zero-crossing point of the first derivative of the EPR signal) was 2.0048, which confirms the presence of carbon-centered radicals.