The Present Status of Breeding Rust Resistant Oats at the Minnesota Station¹

Inheritance of Seedling Reaction to Races 7 and 8 of Puccinia graminis avenae Eriks. and Henn. at High Temperature in Three Oat Crosses1

“…Inoculation, incubation, and record taking were carried out as with the first race. The seedling reactions to races 7 and 8 of the F 3 lines of LMHJA X Andrew and LMHJA X Clinton are presented in table 2 and that of LMHJA X Gopher in table 3. In the cross LMHJA X Andrew, all 145 F 3 lines were resistant to race 7 at 85 ° F., indicating that the factors responsible for resistance to race 7 were the same in the two parents. The classification of the same 145 F 3 lines for reaction to race 8 into resistant, segregating, and susceptible, gave a good fit to a 1 :2:1 ratio as indicated by a P value between 0.50 and 0.30, indicating that the reaction to race 8 at 85 ° F. was governed by a single factor pair.…”

“…If so, it is analogous to the "Canadian" factor of Foote, 3 and Kehr, eta!. (2). Studies at Minnesota, reported by Koo et al/•" have shown that all three types of stem rust resistance are combined in selections made from the cross (Landhafer X (Mindo X Hajira-Joanette)] X Andrew.…”

Reaction of Oats Endowed With the "Canadian" Factors for Resistance to Physiologic Race 6 of Oat Stem Rust in Israel

“…IJntil recently (l), the only type of resistance to race 6 recognized in hexaploid oats was known to be controlled by the BC factors generally referred o as the Canadian (1,6,8), or Hajira genes (8,11,14). The Canadian factors of resistance confer adequate protection from race 6 (and also from race 8) at low and moderate temperatures, whereas above 28-29"C. the attained protection breaks down (1, 6,7, l7).…”

“…The Canadian factors of resistance confer adequate protection from race 6 (and also from race 8) at low and moderate temperatures, whereas above 28-29"C. the attained protection breaks down (1, 6,7, l7). On the other hand, field observations show that varieties endowed with Canadian resistance factors stand up well to stem mst onslaught and only very seldom is their performance in this respect disappointing (1,6).…”