190 SEVENTEENTH REPORT. 



STERTLTZATTOX OF POP CORN. 



BY REED O. BRIGHAM. 



The necessity of obtaining sterile seeds of pop coin, incidental 

 to another problem. l)ecanie evident to me when I began this major 

 j)roblem; conseqnently I have endeavored to find the best method to 

 obtain completely sterile seeds. The problem npon which T am 

 working and for which I need the sterile seeds is, the availability of 

 nitrogen from certain organic compounds in sterile and inocnlated 

 cultures, for the growth of the plants. This work was started and 

 carried on under the direction of Professor James B. Pollock in the 

 Botanical Laboratory of the University of Michigan. Some prelimi- 

 nary work on this was done by Mr. LeVan. Because of the nature 

 of this problem it is evident that complete sterilization of the seeds 

 is necessary. Mr. LeVan used Zea maize (Yellow Dent Corn) in 

 his work, and sterilized the seeds bv means of mercuric chloride. 

 For my work I determined that pop corn would be more advisable. 

 I then proceeded to sterilize by the same method which Mr. LeVan 

 used in his work. However I found that mv plants were severelv 

 injured by this treatment; so that some other means must be ob- 

 tained for sterilization of the seeds. 



I then made a brief review of the literature upon seed steriliza- 

 tion, to try to find some suggestions for a better means. DeZeeuw 

 (2) found that to obtain complete sterility of the seeds and ob- 

 tain good seedlings was very difticult ; he found that cleaning tluid. 

 mercuric chloride, liy<lr(>gen peroxide and bromine water, if prop- 

 erly applied to the seeds which lie used, would ])roduce steriliza- 

 tion; he also found that some of the fungus and bacteria found 

 upon the seeds were not merely on the surface, but were deep in the 

 seed coats; this fact also making the process more difficult. He 

 also suggested that we might have to look to antisepsis rather 

 than to disinfection for i)ractical results. 



Rolnnson (4) concluded in his investigations, that the usual 

 methods of disinfection, employing metallic poisons such as mercuric 

 chloride, are objectionable, it having been shown that these poisons 

 cling to seeds, even after they have been rinsed, in amounts sufficient 

 to be harmful and often fatal to organisms placed on the seeds for 

 inoculation. 



