Abstract only

Development of wheat germplasm with durable rust resistance is a major focus of BGRI. Resistance genes Sr2 and Sr26 are effective against all races of Pgt, including Ug99 and its derivatives. Sr25 is effective against most races. Molecular markers make it easier to pyramid rust resistance genes. In this study, we used diagnostic molecular markers to pyramid three stem rust resistance genes into four high yielding CIMMYT wheat germplasms, as part of an international research project on durable rust resistance in wheat. DNA primer sequences for Sr2 were provided by W. Spielmeyer, CSIRO, Australia. We also used marker BF145935 that is codominant and diagnostic of Sr25. A multiplex PCR assay with marker Sr26#43 and 6A-specific marker BE518379 were used for Sr26. A total of 43 lines were developed with gene pyramids of Sr2, Sr25, and Sr26 in four CIMMYT backgrounds. These lines were checked for homozygosity of markers for three genes at the BC3F2 and BC3F3 (3 backgrounds) or BC2F2 and BC2F3 (1 background) stage. CIMMYT initiated seed increase in El Batan during summer 2011. The germplasm will be included in the 8th Stem Rust Resistance Nursery for distribution in 2013.

Global Wheat Program

English

Lucia Segura

INT0610

CIMMYT Staff Publications Collection