N. E. TOLBERT 



Michigan State University 



{2-Chioroeihy[)tnmethy[ammoniam. Chloride 

 and Related Compounds As Plant 



Growth. Substances' 



(2-Chloroethyl)trimethylammonium chloride and certain other struc- 

 turally related compounds act as plant growth substances (4). These 

 compounds are analogues of choline, and trivial names have been 

 formed from choline. Thus, (2-bromoethyl)trimethylammonium bro- 

 mide has been called bromocholine bromide. The most characteristic 

 growth change after treatment with these compounds is the develop- 

 ment of stockier plants with shorter and thicker stems (5, 6). In most 

 respects the appearance of plants after treatment with derivatives re- 

 lated to (2-chloroethyl)trimethylammonium chloride is the opposite 

 from that obtained with gibberellin, and the effects can be reversed 

 by gibberellin. 



CHEMICAL SYNTHESIS AND BIOASSAY 



The synthesis and analysis of the compounds have been reported 

 (4). In the procedure an amine was reacted with a halogenated hy- 

 drocarbon under controlled conditions to produce a specific product, 

 the structure of which was confirmed by C, H, N, and halide analyses, 

 melting point, and the picrate salt melting point. Thus, trimethyla- 

 mine and 1,2-dibromoethane at 40° C. formed (2-bromoethyl)tri- 

 methylammonium bromide, and (2,3-r7-propylene)trimethylammonium 

 bromide was prepared from allyl bromide and trimethylamine. Since 

 these salts were infinitely soluble in water, aqueous solutions were 

 simple to prepare and to use for treatment of the plants. 



The activity of the compounds was assayed in a procedure with 

 'Thatcher" wheat seedlings (4). Excess aqueous solution of the chem- 

 icals was poured onto the soil once, 1 1 days after planting the seeds. 



^Published with the approval of the Director of the Michigan Agricultural 

 Experiment Station as Journal Article No. 2480. 



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