75 
REPORTS ON RESEARCH FOR 1942 
PLANT PATHOLOGY 
By GeEorRGE M. REED 
Physiologic Races of the Oat Simuts 

Physiologic specialization of fungous pathogens complicates the 
development of resistant varieties of useful plants—vegetables, 
cereals, fruits, and ornamentals. New hybrid combinations of 
desirable qualities with resistance to a particular race of pathogen 
may be obtained, only to discover that strains of the latter have 
originated which also attack the new varieties. Victoria oats was 
introduced from South America in 1927 by the United States 
Department of Agriculture, and has been used extensively in oat 
breeding work by Mr. T. Rk. Stanton, Senior Agronomiust, Division 
of Cereal Crops and Diseases, Bureau of Plant Industry, Wash- 
ington, D. C., and cooperators in several State Agricultural Ex- 
periment Stations. Crosses have been made between Victoria and 
other oat varieties from which many selections have been made, 
some adapted to the South and others to the Central West oat- 
growing sections. In our studies, Victoria has been inoculated 
1e races of loose and covered smut and found to be 
—— 
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with most of t 
resistant. However, the discovery of a race of loose smut of oats 
which attacks Victoria creates a new set of problems. 
Seed of many of the new promising selections of hybrids of 
Victoria and other oat varieties was forwarded to us by Mr. T. R. 
Stanton for testing with the new race of smut. Altogether, 45 
selections of Lee & Victoria and 8 selections of Hairy Culberson 
x Victoria were tested and found to be susceptible. In these 
hybrids, both parents used in the cross were also susceptible to 
the new race of smut. On the other hand, 15 selections of Vic- 
toria <X Richland were found to be resistant; in these selections 
we might expect to find some susceptible ones, as well as resistant ; 
however, all of those selected from the standpoint of other qualities 
proved to be resistant, not only to the new race of smut but to all 
others with which tested. Two selections of Nortex * Victoria 
were also found to be resistant. Dr. George J. Wilds, Coker’s 
Pedigreed Seed Co., Hartsville, S. C., sent us many selections of 
