Application of the Electron Paramagnetic Resonance Spin Probe Technique for Detection of Irradiated Wheat

The fast decay of free radicals makes application of traditional electron paramagnetic resonance (EPR) techniques impractical for detection of irradiated wheats when the storage time is longer than 30 days. In this study, therefore, the effects of irradiation on wheat seeds were investigated by using the EPR spin probe technique. The technique is based on the ability of the spin probes to transfer valuable information related to the changes in the structural characteristics of embryo cell membranes caused by irradiation. As a result of irradiation, the enviroment of the spin probe is modified and this modification can be followed from the recorded spectra. The doses studied were 1.0, 2.5, 10.0, and 20.0 kGy. An aqueous solution of 16-doxyl stearic acid (16-DSA) was used The embryos were detached using a steel needle and kept in 16-DSA solution for 2.5 hr and washed with distilled water. The spectra of the samples were recorded. The detection of irradiated wheats by this technique was possible at doses of ≥2.5 kGy. An important advantage of this approach is that it is applicable even after eight months of storage.