Wheat germplasm development by gene pyramiding for resistance to race TTKSK of stem rust

To develop wheat germplasm with resistance to race TTKSK of stem rust, five stem rust resistance genes were used to produce pyramids with up to 4 Sr genes of various combinations by marker-assisted selection (MAS) and doubled haploid (DH) technology. Thirteen desired pyramids with 2 to 4 of the Sr genes were recovered, and wheat cultivar Hoffman was improved by stacking Sr35 and Sr36. TTKSK resistance test showed that pyramided lines with three or four genes plus improved Hoffman with Sr35+Sr36 were all immune to TTKSK. This type of germplasm will be a useful tool for the production of cultivars with long-term sustainability.

Automated summary

By using marker-assisted selection and doubled haploid technology, five stem rust resistance genes were stacked to produce 13 desired combinations. The wheat cultivar Hoffman was improved by stacking Sr35 and Sr36. The pyramided lines with three or four genes and improved Hoffman with Sr35+Sr36 were all immune to TTKSK.