Identification of SSR Marker Linked to Leaf Rust Resistant Gene Lr۲۴ and Marker Assisted Transfer of Leaf Rust Resistance Genes into Bread Wheat

A study was conducted to identify SSR markers linked to leaf rust resistance genes Lr۲۴ and Lr۲۸ and to be used for Marker-Assisted Selection (MAS) to transfer both genes to a widely cultivated wheat variety MP ۳۲۹۹ under rainfed condition. F۲ individuals of the cross MP ۳۲۹۹×NIL PBW ۳۴۳ were used for generating genotypic data employing closely linked SCAR markers S۷۳۷۱۹ and S۴۲۱۵۷۰ to Lr۲۴ and Lr۲۸, respectively, and further subjected to bulk segregant analysis. A total of ۷۰ SSR markers that amplify sequences on long arm of chromosome ۳D and long arm of chromosome ۴A were used for polymorphism assay between the parents MP ۳۲۹۹ and NIL PBW ۳۴۳. Eighteen SSRs were polymorphic between the parents, of which ۱۰ were located on chromosome ۳DL and eight on chromosome ۴AL. Three SSR markers out of ۱۸ polymorphic markers differentiated two contrasting bulks and further used for F۲ genotyping. Finally, one SSR marker i.e. ‘barc ۷۱’ linked to SCAR marker SCS۷۳۷۱۹ at a distance of ۳.۳۶ cM based on the per cent recombination frequency was identified. Thus, the newly identified SSR marker barc ۷۱ linked to Lr۲۴ can serve as a useful marker in gene pyramiding instead of SCAR marker SCS۷۳۷۱۹.

کلیدواژه ها:

Bulked segregant analysis ، Major gene ، Marker-assisted selection ، Seedling resistance ، Polymorphism