Delayed luminescence of seeds: are shining seeds viable?

Delayed luminescence (DL) has been widely studied for its applications in developmental biology and describes a phenomenon whereby biological materials radiate for a relatively long time (seconds and more) after illumination. Researchers have postulated that DL is potentially useful for determining the physiological status of biological materials, including crop seeds. Until recently this claim only remained within academia and there have been no known reports for the advancement of its use in seed testing and genebank management. This article examines the gaps in knowledge for adopting DL for seed testing by reviewing the history of DL applications in analytical studies of crop seeds and the incompletely understood mechanisms within seeds for displaying DL. We identified a need for more experimental data to validate the DL mechanisms in seeds before the procedure can be used for seed testing.