ABSTRACT
Wheat was germinated at 15°C on sand of varying moisture content. Coumarin only inhibited germination when the seeds contacted liquid water. Full expression of dormancy (sprouting resistance) was only seen under these conditions. A crack in the pericarp within the brush region, appears to be formed during seed maturation. It allows rapid movement of dye solution beneath the pericarp in the dorsal surface. Water movement through this pathway may transfer inhibitors to the embryo.
Effects of temperature on interactions between water and polymers are briefly reviewed. It is suggested that temperature and rate of drying would determine the final conformation of polymers within seed structures thereby determining physical properties on rehydration. These effects could be the basis of variation in germinability and dormancy.
