Wildwheatspecies are proven sources of resistance that can be
transferred to commercial varieties. Combining multiple/R/genes is a
widely accepted gene stewardship strategy to help enhance the resistance
as the simultaneous defeat of two or more effective/R/genes is less
likely than the defeat of either genealone.

The introgression of stem rust resistance gene/Sr26/derived from tall
wheatgrass into common wheat is one of the most successful examples of
utilization of resistance resources from wheat wild relatives./Sr26/was
transferred to wheat and the resistance has remained effective against
all known/P. graminis tritici/(Pgt) pathotypes, including all races from
the Ug99 group. A second/Sr/gene,/Sr61/, has been identi??ed in the South
African wheat accession W3757.

A compelling reason for cloning/R/genes is the opportunity to combine
them into a single trait. The most desirable/Sr/genes to be combined
into a transgene cassette are those with broad-spectrum effectiveness
against diverse Pgt races. Virulence to most of the cloned/Sr/genes has
been documented making isolation of/Sr26/and/Sr61/a valuable addition
for inclusion into future transgenic cassettes.

Combining resistance genes to improve wheat yields - BGRI (cornell.edu)
[bgri.cornell.edu]