REPORTS OX RESEARCH EOR 1927 

 Plant Pathology 

 By George M. Reed 



The Inheritance of Smut Resistance in Oats 



The studies on the inheritance of oat smut resistance have beer 

 continued. The hehavior of the progenies of various hybrids 

 with reference to both the loose ( ('slilcn/o Arenac) and covered 

 (('. levis) smuts has been determined. 



In the last annual report a bricl aatement regarding the b 

 havior of the second generation plants ol a cross between Black 

 Mesdag and I fnlldess was given. < >ne of these varieties (Black 

 Mesdag) is highly resistant while the other (Hull-less) is com- 

 pletely susceptible to both loose and covered smut. As reported 

 last y< ir, -\(> ? ;econd general ion plant in-longing [: , four different 

 families were inoculated with loose smut and J 07 (23 per cent.) 

 were infected; 196 plants were ino< dated with nvered smut and 

 40 (20.4 per cent.) were infected. 



During the past year, data on the third generation of dies* 

 progenies were obtained. A total of 578 third generation families 

 were grown, each family containing on the average about ?,() plant-, 

 half of the individuals feme, inoculated with loose smut and the 

 other half with covered. It was determined that 531 of these 

 families were readily classified as either resistant, segregating or 

 susceptible to both species of smut. The remaining 47 families 

 gave a dissimilar reaction, bui. whether this indicates a real dif 

 ference in the inheritance of the resistant quality in these families 

 or merely accidental variations in these experiments remains u 

 be determined. In general, a third generation family resistant to 

 one smut is resistant to the other, and a family susceptible to one- 

 is susceptible to the other. 



In general, the behavior of these families corresponds with the 

 data obtained in the second generation and seems to correspond 

 with the interpretation that resistance to smut is 

 segregation of resistant and susceptible individuals 



