Investigation of the distribution of stable paramagnetic species in an apple seed using X-band EPR and EPR imaging

摘要

This study investigated the location and distribution of paramagnetic species in apple seeds using electron paramagnetic resonance (EPR) and X-band (9 GHz) EPR imaging (EPRI). EPR has detected two dominant paramagnetic species. Based on the observed g-values and hyperfine components these two species were assigned to a stable radical and Mn²⁺ specie. The signal from the stable radical was noted at g ~ 2.00, and was strong and relatively stable. Subsequent noninvasive EPRI of the radicals revealed that they were located primarily in the seed coat, with very few radicals observed in the cotyledon of the seed.