**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** LEAF RUST AND STRIPE RUST ARE THE MOST WIDESPREAD AND DEVASTATING WHEAT DISEASES GLOBALLY. THE CONTINUOUS DISCOVERY AND DEPLOYMENT OF RUST RESISTANCE GENES ARE NEEDED TO ACHIEVE DURABLE RUST RESISTANCE. WE WILL EXPLORE LEAF RUST AND STRIPE RESISTANCE IN US HARD RED WINTER WHEAT. WE SELECTED 767 BREEDING LINES AND CULTIVARS FROM RECENT REGIONAL GERMPLASM OBSERVATION NURSERY, NORTHERN REGIONAL PERFORMANCE NURSERY, AND SOUTHERN REGIONAL PERFORMANCE NURSERY. THIS GERMPLASM WILL BE EVALUATED AT THE SEEDLING STAGE AND ADULT-PLANT STAGE IN MULTIPLE LOCATIONS IN THE US. THIS GERMPLASM WAS GENOTYPED USING MULTIPLEX RESTRICTION AMPLICON SEQUENCING AND 63,888 SINGLE NUCLEOTIDE POLYMORPHISM MARKERS WERE GENERATED. BOTH PHENOTYPIC AND GENOTYPIC DATA WILL BE USED FOR GENOME-WIDE ASSOCIATION STUDIES (GWAS). THE GWAS WILL IDENTIFY LEAF RUST AND STRIPE RUST RESISTANCE GENES IN CURRENT US WINTER WHEAT. USER-FRIENDLY MARKERS ASSOCIATED WITH THE DISCOVERED GENES WILL ALSO BE DEVELOPED FOR USE IN MARKER-ASSISTED SELECTION. LINKAGE MAPPING IS ANOTHER APPROACH THAT WILL BE USED TO IDENTIFY AND CHARACTERIZE LEAF RUST AND STRIPE RUST RESISTANCE GENES IN THE HARD WINTER WHEAT CULTIVAR 'BIG COUNTRY'. BASED ON PRELIMINARY DATA, BIG COUNTRY HAS NOVEL RUST-RESISTANCE GENES THAT SHOULD BE EXPLORED. WE ARE DEVELOPING A DOUBLE HAPLOID (DH) POPULATION FROM A CROSS BETWEEN THE RUST-RESISTANT CULTIVAR, BIG COUNTRY, AND THE RUST SUSCEPTIBLE CULTIVAR 'JAGALENE'. THE DH LINES WILL BE EVALUATED FOR LEAF RUST AND STRIPE RUST AT BOTH SEEDLING AND ADULT-PLANT STAGES AND GENOTYPED USING GENOTYPING-BY-SEQUENCING. MAPPING WILL THEN BE PERFORMED TO IDENTIFY RUST RESISTANCE GENES IN BIG COUNTRY.