Enhancing rust resistance in wheat through marker assisted backcross breeding

Rusts are among the most devastating fungal diseases of wheat worldwide causing major yield losses. The most effective way to control yield losses caused by rusts is by incorporating genetic resistance in wheat cultivars. In view of this, marker assisted backcrossing (MABC) was performed to transfer three highly effective genes, two for leaf rust resistance (Lr19/Sr25 and Lr24/Sr24) and one for stripe rust resistance (Yr15) into a wheat cultivar UP 2338. The Avocet/ Yr15 (Yr15) was used as donor for stripe rust and FLW 8 and FLW 21 were the donors for Lr19/Sr25 and Lr24/Sr24, respectively. Two linked SSR markers, Xgwm273 for Yr15 and Xwmc221 for Lr19/Sr25 and a SCAR marker, SCS1302 for Lr24/Sr24 were used for foreground selection to select plants carrying respective gene(s). Foreground selection coupled with background selection identified plants homozygous for stripe rust and leaf rust resistance and materials have been advanced up to BC3F3 stage. Findings of this investigation show the usefulness of marker assisted selection in precise introgression of the genes for stripe rust and leaf rust resistance.