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REPORTS ON, RESEARCH BOR, 1932 
PEANT PATHOLOGY 
3y GEorGE M. REED 
Studies on the Inheritance of Resistance of Oat Hybrids to 
Loose and Covered Smut 
During the past year many third and fourth generation progenies 
of several different oat crosses were studied. The third genera- 
tion progenies were grown from second generation plants which 
had not been inoculated and, consequently, no susceptible second 
generation plants had been eliminated. Usually, there were two 
sets of seed of each progeny, one set being inoculated with the 
loose smut and the other with the covered. In this way, the 
behavior of the different progenies to both of the smuts was de- 
termined. Altogether, third generation progenies from 15 oat 
hybrids were grown. ‘These different hybrids involve quite dis- 
tinct types of combinations of smut resistance. 
There were 88 I’, progenies of Hybrid 16, Gothland & Victor, 
inoculated with the covered smut, and 32 of these were classified 
as resistant, no infected plants being observed, 44 segregating, the 
percentage of infection being less than 50, and 12 susceptible, a 
few actually giving 100 per cent. infection. ‘The Gothland parent, 
as usual, gave negative results with the covered smut, while Victor 
was practically 100 per cent. infected. There were 28 third gen- 
eration progenies of this hybrid inoculated with the loose smut 
and, out of a total of 633 plants inoculated, 603 (95.2 per cent.) 
were infected. Since both varieties are very susceptible to the 
loose smut, the results obtained with the third generation progenies 
are in harmony with the behavior of the two parents. 
Hybrid 18, Silvermine & Black Mesdag, and Hybrids 34, 35 and 
36, Early Champion X Black Mesdag, involve a similar com- 
bination of resistance in the parents. Silvermine and Early 
Champion are very susceptible to both loose and covered smut, 
while Black Mesdag is resistant. 
There were 40 I, progenies of Hybrid 18 inoculated with the 
loose smut and of these 15 were resistant, 18 segregating, and 
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