INTROGRESSION OF STEM RUST RESISTANCE GENE Sr47 IN THE WHEAT VARIETY CIRNO C2008

Abstract

Stem rust, caused by Puccinia graminis f. sp. Tritici E. & H., is a threat to wheat production in most wheat growing areas in the world. The Sr47 resistance gene, identified in Aegilops speltoides and transferred to crystalline wheat, confers resistance not only to Ug99 and derived races, but also to other stem rust races present in Mexico and other parts of the world, including the Sicilian race, recently identified as TTTTF. In a resistant cultivar, introgression of the Sr47 gene can be tracked by selection assisted by molecular markers such as Xwms501 (monogenic dominant), Xgwm47 (dominant in repulsion), Xrwgs38 and Xgpw4165 (codominant). Conventionally, when a susceptible cultivar is used, the presence of the resistance gene could be diagnosed by the response to the RTR race of stem rust in the case of Mexico; however, Cirno C2008 is resistant to Ug99 (TTKSK), RTR and other stem rust races present in Mexico. Molecular analysis of 141 BC1F3-derived families from the DAS15 × Cirno C2008 cross using the molecular markers Xwms501, Xgwm47, Xrwgs38 and Xgpw4165 allowed the identification of families with the insertion of the Sr47 gene.