Adequate Rust Resistance in Oats

Abstract

For the past 60 years, the use of single genes for specific resistance has formed the basis for most conventional breeding programmes for oat stem rust improvement. While somewhat successful in keeping ahead of the rust pathogen the new resistant cultivars eventually had to be replaced after brief stints of production. Oat breeders, too, were plagued by a paucity of specific resistances to Puccinia graminis f.sp. avenae. In 1965 the super-virulent race 94 (NA-30) surfaced which was capable of attacking all the stem rust resistance genes then known in the cultivated oats in North America. Since that period new sources for stem rust resistance have been reported, many of which were transferred from the wild species of Avena to the cultivated species. Their exotic source of origin, however, does not necessarily assure a more prolonged existence in the cultivated oat if the appropriate race should evolve. One choice for the breeders, however, is to combine these new sources of resistance into various combinations.