Regulation of seed dormancy m <i>Elaeagnus umbellata</i> by endogenous growth substances

Abstract

The growth-substance content of fruits of Elaeagnus umbellata was examined as part of an investigation of the regulation of seed dormancy of this species. Extracts of dormant seed fractions were separated chromatographically in various solvents and biological activity was determined in a lettuce-seed and a cucumber-seed bioassay. The bioassays showed that a growth-inhibiting substance with an R f value similar to coumarin was present throughout the dormant seed. Fluorescence also showed that the inhibitor closely resembled coumarin.Activity of the inhibitor did not decrease during 90 days at 5 °C, and evidence indicates it may be physiologically active in preventing germination. On the other hand, germination-promoting substances that may counteract the effect of the inhibitor were found to be produced in the embryo during low-temperature afterripening.