qn 
bo 
Plant Pathology | 
REPORTS ON RESEARCH FOR 1928 
By Grorce M. Reep 
Oat smut investigations 
The study of the inheritance of the resistance of oat smut in 
various oat hybrids has been continued. The very extensive data 
with loose (Ustilago avenac) and covered (U. levis) smuts already 
obtained have been published during the past year. These data 
included the results with a number of oat hybrids, as Hull-less 
Black Mesdag, Silvermine « Black Mesdag, Hull-less & Victor, 
Early Gothland & Hull-less, Early Gothland & Victor and Mon- 
arch & Hull-less. Most of the data published were obtained with 
the second hybrid generation, in which segregation may be ex- 
pected. However, the data on the third generation progenies of 
the hybrids between Hull-less and Black Mesdag were included. 
In the hybrids between Hull-less and Black Mesdag, resistance 
scemed to be the dominant character and segregation occurred in 
the second generation on the basis of three resistant plants to one 
susceptible. In the data already published, 465 plants were inocu- 
lated with the loose smut and 107 (23 per cent.) were infected: 
in another series, 196 plants were inoculated with covered smut 
and 40 (20.4 per cent.) were infected. During the past year 
additional second generation plants of these hybrids were inocu- 
lated. In the series with loose smut 117 plants were inoculated 
and 23 (19.6 per cent.) became infected, and in the series with 
the covered smut 178 were inoculated and 38 (21.3 per cent.) 
were infected. In these experiments also, the Black Mesdag 
parent proved to be highly resistant, negative results having been 
obtained with both smuts. On the other hand, the Hull-less par- 
ent, as usual, gave high percentage of infection. These data are 
in harmony with those previously secured. 
In my account of the behavior of the third generation of these hy- 
brids, a number of progenies seemed to show a dissimilar behavior 
toward the loose and covered smut. A total of 578 third genera- 
