Close genetic linkage of genes conferring adult-plant resistance to leaf rust and stripe rust in wheat.

Independently derived Canadian back-cross lines possessing the adult-plant leaf-rust resistance gene Lr34 also display adult-plant resistance to stripe rust. The genes for resistance to both diseases must be closely linked. Other back-cross derivatives selected for resistance to stope rust in Australia displayed leaf-rust resistance in selection nurseries. Circumstantial evidence indicated that the two sets of materials possess the same genes. The donor sources are known to possess long-lasting or durable resistance to either disease. The inference that part of each durable resistance source may involve very closely linked genes has important ramifications for genetic understanding, manipulation and agricultural deployment of rust resistance genes. [ABSTRACT FROM AUTHOR]