A Gene for Resistance toPuccinia graminisf. sp.triticiThat is Present in Wheat Cultivar H-44 but not in Cultivar Hope

Abstract

A backcross line of Marquis wheat [Triticum aestivum] carrying gene Sr9d from ''H-44'' was more resistant to P. graminis f. sp. tritici than was a 2nd backcross line carrying Sr9d from ''Hope''. The difference in reaction was caused by a 2nd gene for resistance in the ''H-44'' line. The gene was present in ''H-44'' but was not present in ''Hope'' or the Sr9d (''Hope'') line. The nature of the resistance conferred by this 2nd gene and the relationship of the gene to other genes for resistance in ''Hope'' and ''H-44'' are discussed.