2l6 



RESEARCHES ON FUNGI 



Hanna, Vickery and Pucher 1 isolated trimethylamine from the 

 spores of Tilletia laevis and have thus shown that the odour of the 

 spores is due to a definite chemical substance. Hanna 2 has observed 

 that trimethylamine is present in some strains of T. tritici and 

 absent in others, so that it is impossible to differentiate T. tritici 

 and T. laevis from one another on the basis of odour. 



Both Flor 3 and Hanna have succeeded in crossing Tilletia tritici 

 and T. laevis, thus obtaining hybrid bunt balls. Using pure cultures 

 made from single secondary conidia, which are apparently haploid, 

 Hanna 4 made crosses between T. laevis which had trimethylamine 

 and a strain of T. tritici which lacked trimethylamine. The first- 

 generation hybrid spores resulting from this cross were smooth, as 

 was to be expected from the work of Flor, and they emitted an 

 odour of trimethylamine. In this cross, therefore, the factors for 

 smooth spore-wall and odour were dominant. 



The Germination of the Chlamydospores on Agar. — Brefeld 

 germinated the chlamydospores of Tilletia tritici and cultivated the 

 fungus successfully in nutrient solutions but less successfully on solid 

 media, as the latter became contaminated with moulds in the course of 

 about ten days. Sartoris, 5 in 1924, appears to have been the first to 

 germinate the chlamydospores and to keep the fungus in pure culture 

 on a solid medium. His solid medium consisted of agar containing 

 oatmeal, malt extract, or the solution recommended by Leonian. 6 



1 W. F. Hanna, H. B. Vickery, and G. W. Pucher, " The Isolation of 

 Trimethylamine from Spores of Tilletia levis, the Stinking Smut of Wheat," Journ. 

 Biol. Chem., Vol. XCVII, 1932, pp. 351-358. 



2 W. F. Hanna, " The Odor of Bunt Spores," Phytopathology, Vol. XXII, 1932, 

 pp. 978-979. 



3 H. H. Flor, " Heterothallism and Hybridisation in Tilletia tritici and T. 

 levis," Journal of Agricultural Research, Vol. XLIV, 1932, pp. 49-58. 



4 W. F. Hanna, " The Odor of Bunt Spores," loc. cit., p. 979. 



5 G. B. Sartoris, " Studies in the Life History and the Physiology of Certain 

 Smuts," Amer. Journ. Bot., Vol. XI, 1924, pp. 617-647. 



6 Leonian agar has the following composition 



Dihydrogen potassium phosphate 



Magnesium sulphate 



Peptone 



Maltose 



Malt extract 



Agar 



Water . 



