166 



THE FLOWERING PROCESS 



2 4 



HOURS 



6 

 DURING 



8 



THE 



10 

 DARK 



12 14 



PERIOD 



16 



Figure 9-8 



Flowering as influenced by a 2-hr period of high or low temperature 



applied during a 16-hr inductive dark period (February 15, 1962). Level 



parts of the curves represent the 2-hr "interruption" periods. Data 



previously unpubUshed. 



Applied Chemicals in the Study of Flowering (32) 



1. The Problem of Detecting the Flowering Hormone 



Ideally, we should be able to grind up a leaf, keep the enzymes 

 suspended in a buffer solution, and study the synthesis of flowering 

 hormone in the dark. In this way we could learn all about the 

 biochemistry of its synthesis. Such a laboratory approach is presently 

 impossible, because we have no way of measuring the flowering 

 hormone except to observe the flowering of a test plant. Even this 

 would not be a serious limitation if we were able to apply an extract 

 of the flowering hormone to a vegetative plant and cause it to flower. 

 Such a procedure has often been tried. Since about 1938, when the 

 concept of a flowering hormone was first developed, various workers 

 in laboratories all over the world have searched for the proper 

 extract. For example, James Bonner (9) estimates that he personally 

 has made at least 2000 diff'erent extracts. 



Occasionally we hear reports of success in these experiments. At 

 this time a group at Long Beach State College in California, under 



