Identification of molecular marker linked to stem rust resistance gene in synthetic hexapolid lines of wheat (Triticum aestvium L.)

Abstract

In order to enrich the molecular markers linked to wheat stem rust resistance gene and to facilitate the marker-assisted selection in breeding programme, bulk segregation analysis was carried out for gene tagging using F2 segregating population derived from cross between wheat synthetic 4 line with resistant gene (Sr gene carrier) and a common wheat variety Agra local (susceptible to wheat stem rust). This Sr gene carrier synthetic 4 was derived between a cross Triticum turgidum (AABB) and Triticum tauschii (DD). A total of 35 SSR primers covering D and B Genome on the basis of chromosomal location of resistance genes were screened. The SSR marker namely Xgwon106, Xgwm432, Xgwm533 and Xgwm369 have revealed polymorphism among the parents used for study. The SSR Xgwm 533 was found to be putative linked with stem rust resistance gene while the marker Xgwm 389 was co- segregating with Xgwm 533. Marker Xgwm 533 and Xgwm 389 were taken from B genome. Hence, the stem rust resistance gene presumed to be located on 3-B genome of wheat. The use of these markers in combination with others markers could better predict the presence of stem rust resistance gene in wheat genome. Key words: Stem rust (Puccinia graminis f.sp. tritici), molecular tagging, bulk segregation analysis, synthetic hexaploid wheat, SSR primers.