A Calorimetric Study of the Changes in Lipids during Seed Storage under Dry Conditions

Changes in the lipid constituents of seeds are believed to be associated with losses of seed viability during storage. The physical properties of lipids in seeds of genetically similar backgrounds but varying ages were compared using differential scanning calorimetry. The technique measures the temperature and energy associated with lipid-melting transitions and is noninvasive. Although differences in the temperature at which lipids melted were sometimes observed among deteriorated and fresh seeds, the direction of the change was inconsistent among species tested. For all species tested except tomato, there was a decrease in the energy associated with the lipid melt in deteriorated samples, and the change occurred at a similar rate as the loss of seed vigor. The data suggest that there are changes in the lipid components of seeds that are associated with seed deterioration and that these changes can be measured using differential scanning calorimetry.