CHAPTER 1 1 



Radiation Studies on Fungi^ 



Seymot^k Pompek- and K. C. Atwuod 



Biologtj Division, Oak Ridge National Laboratory 

 Oak Ridge, Tennessee 



Introduction: Ultraviolet radiation: Wave-length dependence in the xdtraviolet — 

 Survival and mutation kinetics — Modifying effects on ultraviolet action. Ionizing 

 radiations: Comparison of different ionizing radiations — Dose-effect curves — Modifying 

 factors — Conclusions. References. 



INTRODUCTION 



The desirability of fungi as objects of radiobiological investigation 

 arises simply from the ease of experimentation with the \arious kinds of 

 durable, easily enumerable spores or other formed elements which are 

 available. Certain fungi offer the combined advantages of the mass 

 techniques peculiar to microbial genetics and the opportunity for detailed 

 genetic analysis. As might be expected, no general lines of approach have 

 been developed exclusively in the fungi, and the experimental work can- 

 not be said to form a unified body of fact. It is the purpose of the present 

 review to indicate briefly the sources and significance of divers contri- 

 butions in the area of radiation effects in this group of organisms. No 

 particular effort has been made to cover work done prior to 193(), when a 

 review of this subject was presented (Smith, 1936). 



Numerous agents are well known for their ability to cause genetic 

 changes in biological material, and many, if not all, have been used on 

 fungi. Of prime importance for this discussion are, of course, various 

 radiations. These include ultraviolet, X rays, a particles, and neutrons. 

 By far the greatest amount of work on fungi has been done with X and 

 ultraviolet radiations. Various chemicals are also known to be capable 

 of causing changes similar to those caused by radiations. From the 

 standpoint of radiation biology, the study of radiomimetic chemicals is 

 interesting because of the possibility that a large portion of the effects oi 



^ Manuscript prepared and work at Oak Ridgr jiorformed under Contract No. 

 7405-png-26 for the Atomic Energy Comini.ssion. 



^ Present address: The Fleishmann Laboratories, Stamford, Conn. 



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