J. p. NITSCH 



and 

 C. NITSCH 



Laboratoire du Phytotron 

 Gif-sur-Yvette (S. et O.), France 



Growth Factors in the Tomato Fruit' 



The time at which one of us (J.P.N.) first became interested in the 

 juice of tomatoes as a source of growth factors goes back to January, 

 1949, when an effort was made to grow excised ovaries in sterile cul- 

 ture. At the suggestion of Mr. E. F. Vacin, who had been using to- 

 mato juice (TJ) to improve the growth of orchid seedlings, tomato 

 juice was added to the media which were to receive excised tomato 

 ovaries. This resulted in the successful development of tomato fruits 

 in sterile culture (20,21,22). Tomato juice was tried, then, on stan- 

 dard strains of tissue cultures, namely crown-gall strains of Helian- 

 thus annuus (De Ropp's PHI), of Nicotiana tabacum (Morel's), and 

 of Opuntia monacantha (Morel's). In all these cases, after an initial 

 slow start, growth burst into vigorously proliferating cultures (23). The 

 fact that none of the strains used required auxin to grow indicated at 

 once that one was dealing here with a factor quite different from an 

 auxin. A more extensive study of this factor was indicated. It is clear 

 from the literature that other workers also observed biological effects 

 resulting from the addition of tomato juice. 



PHYSIOLOGICAL EFFECTS OF TOMATO JUICE 



Stimulation of Growth in Microorganisms 



Some 20 years ago, tomato juice was a popular source for "bios" 

 factors for bacteria, yeasts, etc. (see, e.g., 4, 18, 19). Interest in the 

 "bios" substances faded, however, as they were progressively identified 



^A part of the work reported here was supported by the National Science 

 Foundation (Grant G-4046) and the National Institutes of Health, Bethesda, Md. 

 (Grant RG-4840). 



[ 687 ] 



