BIBLIOGRAPHY 415 



in Aspergillus niger (155) and Coccomyces hiemalis (148), in both of 

 which limited evidence suggests than an inhibitor is present in the spore 

 at the time of its formation and can be removed by washing. 



Preliminary evidence has been reported by Forsyth (91) that Puccinia 

 graminis tritici uredospores produce 2-methyl-butene-2 (trimethylethyl- 

 ene), and that this compound inhibits spore germination. Whether 

 this is the effective substance remains to be seen. 



Self-inhibition has at least one obvious ecological function, that ger- 

 mination of spores within the fructification is minimized. The unger- 

 minated spore is much more resistant to the environment than the 

 germinated and is, of course, the effective agent of dispersal. Although 

 germination in situ has occasionally been reported, it appears to be the 

 exception; this suggests that self-inhibition is a general principle in 

 spore physiology, and that it is not limited to the few fungi so far studied. 



At the other extreme from self-inhibition is the situation in Ophiobo- 

 lus graminis (210); ascospores germinate slowly if isolated singly, more 

 rapidly if many spores are present. Still a different effect occurs in 

 certain myxomycetes (257), in which spore germination is promoted 

 by the medium upon which a culture has grown. 



Plant materials, besides increasing spore germination through nutri- 

 ent effects or carbon dioxide evolution, in some cases inhibit germina- 

 tion, e.g., of Botrytis cinerea (36, 38) and Venturia inaequalis (106). 

 The mechanism of these effects, as that of the inhibition of spore ger- 

 mination in soil (50), is still unknown. Microbial products may also 

 inhibit germination; these include, besides the fungitoxic antibiotics, 

 the compound fusaric acid (Chapter 8), produced by several Fusarinm 

 spp. and active against Ustilago zeae (104). 



BIBLIOGRAPHY 



1. Abe, T. 1933. Ann. Phytopathol. Soc. Japan 2: 502-512. 



2. Allen, P. J. 1955. Phytopathology 45: 259-266. 



3. Arens, K. 1929. Jahrb. wiss. Botan. 70: 57-92. 



4. Armolik, N. and J. G. Dickson. 1956. Phytopathology 46: 462-465. 



5. Atwood, K. C. and F. Mukai. 1955. Genetics 40: 438-443. 



6. Bailey, L. D. 1923. Minn. Univ. Agr. Exp. Sta. Tech. Bull. 16: 1-31. 



7. Bajaj, V., S. P. Damle, and P. S. Krishnan. 1954. Arch. Biochem. Biophys. 50: 

 451-460. 



8. Baker, G. E. 1945. Mycologia 37: 582-600. 



9. Balls, W. L. 1905. New Phytologist 4: 18-19. 



10. Beauverie, J. 1924. Compt. rend. (Paris) 179: 993-996. 



11. Becker, J. 1929. Kuhn-Arch. 19: 353-411. 



12. Bellinger, H. 1956. Zentr. Bakteriol. Parasitenk. Abt. II, 109: 13-16. 



