Analysis of Photoperiodism in Flower Induction

Now that we are familiar with the phenomenon, let us consider a few data relating to its causation. First of all it was shown that the leaf was the 

The light stimulus is received by the leaf but the pivotal event takes place in the shoot meristem. This finding alone suggests the existence of a flowering hormone even in plants that are dependent on day length, which migrates from the leaves to the apical meristem. Another experi- 

Finally, here again graft experiments suggest the existence of a 

In view of apparently convincing indications of the existence of a flowering hormone it is reasonable to ask whether this substance has 

We have just learned that interruption of the dark period of short day plants can prevent the induction of flowering. These light breaks involve 

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