MOLECULAR CHARACTERIZATION OF PAKISTANI SPRING WHEAT (TRITICUM AESTIVUM L.) LINES FOR RESISTANCE TO YELLOW RUST (PUCCINIA STRIIFORMIS), LEAF RUST (PUCCINIA TRITICINA), AND STEM RUST (PUCCINIA GRAMINIS) UTILIZING MICROSATELLITE MARKERS

Wheat rust, including leaf rust (Puccinia triticina f. sp.tritici), stripe rust (Puccinia striiformis f. sp.tritici), and stem rust (Puccinia graminis f. sp.tritici), is among the most destructive foliar diseases impacting wheat production in Pakistan.This study aimed to evaluate the status of various resistance genes against leaf, stem, and stripe rust in improved Pakistani wheat breeding lines and to identify the suitable lines for gene pyramiding aimed at rust resistance.Forty advanced wheat lines were selected from the National Wheat Disease Screening Nursery (NWDSN) and National Uniform Wheat Yield Trials (NUWYT) for testing at the seedling stage based on the gene-for-gene resistance concept.These lines were subjected to field experiments employing a Randomized Complete Block Design at the National Agriculture Research Center, Islamabad Pakistan.The Yr29 gene was indicated through the amplification of SSR markers Xwmc367 and Xgwm44 in 22 to 35 wheat lines.Additionally, Yr26 and Yr18 genes were amplified in 39 and 17 lines, respectively.The stem rust resistance gene Sr25 (marker Xgwm539) was identified in 30 lines, while Sr9 (marker Xgwm1117) was found in 36 genotypes.Moreover, Wmc344 amplified a 150 bp fragment in 38 wheat lines which shows the presence of Lr19/Sr25 gene.Lr14 and Lr60 were present in 12 and 37 lines, respectively.The resistance resources identified in this study are expected to assist breeders in creating new rust-resistant wheat varieties through gene pyramiding.