Preservation of dormancy in freshly harvested wheat grain

Abstract

Freshly harvested grain from 14 varieties of wheat was stored in a deep-freezer at 15¦C, or alternatively, in an air-conditioned seed room at 12¦C for periods of up to 9 months. Freeze-storage preserved the germination rate of hand-threshed grain at the level observed at harvest, provided that the moisture content of the grain had reached 12%. When frozen grain was transferred to 12¦C storage, its germination rate improved with time in parallel with changes observed in freshly harvested seed stored at 12¦C from the time of harvest, i.e. after-ripening was not adversely affected by the freezing treatment. This technique should enable greater quantities of material to be screened for low germinability at harvest ripeness and for tolerance to pre-harvest sprouting damage. It also allows the provision of a continuous supply of uniform material for investigations of dormancy and grain after-ripening.