Beschreibung:
<jats:p>The physiological state of lettuce seeds could be divided into three distinct stages. The first is the dormant stage, the second is the nondormant one and the third is the deteriorating one. The dormant and the deteriorating stages can be classified further into three phases, respectively, by the actions of germination temperature, red light, and chemical substances.</jats:p><jats:p>The effects of an exposure to red light and of the application of gibberellic acid A<jats:sub>3</jats:sub> and thiourea on germination can be divided into two functions: 1) dormancy‐releasing effect on dormant seeds, and 2) stimulating effect on aged seeds which have reduced their germinability.</jats:p>