An Evaluation of EPR Measurements of the Organic Free Radical Content of Individual Seeds in the Non-destructive Testing of Seed Viability

Abstract

Hepburn, H. A., Goodman, B. A., McPhail, D. B., Matthews, S. and Powell, A. A. 1986. An evaluation of EPR measurements of the organic free radical content of individual seeds in the non-destructive testing of seed viability.—J. exp. Bot. 37: 1675–1684. Electron paramagnetic resonance (EPR) spectra of individual intact seeds of a range of legumes and brassicas have been obtained in order to measure their organic free radical contents. No relationship was found between free radical content and seed viability or early seedling growth for both legumes and brassicas. The testa had a much greater free radical concentration than either the embryo axes or the cotyledons for all cultivars of seed tested. The general high free radical content of the testa suggests that there is little possibility of EPR being used to predict the viability of individual seeds. The spectroscopic splitting factor of g = 2·0045 reported for the intact seeds is consistent with the radicals' arising from melanic type compounds.