**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** DWARF AND COMMON BUNT DISEASE OUTBREAKS ARE LIKELY TO INCREASE DUE TO THE EXPANSION OF ORGANIC WHEAT PRODUCTION SYSTEMS, CHANGING CLIMATIC CONDITIONS, AND THE EVOLUTION OF NEW PATHOGEN RACES. ACCORDING TO THE USDA NASS CENSUS OF AGRICULTURE, THE UNITED STATES HARVESTED 450,854 BUSHELS OF ORGANIC WHEAT IN 2017, WITH UTAH RANKING FOURTH AT 37,736 BUSHELS AND IDAHO RANKING EIGHTH AT 19,737 BUSHELS. SALES OF ORGANIC FOOD PRODUCTS IN THE UNITED STATES GREW AT A RATE OF 6.4 PERCENT IN 2017, AND AS ORGANIC WHEAT ACREAGE GROWS TO KEEP PACE, HOST RESISTANCE IS NECESSARY TO PROTECT AGAINST INFECTION WITHIN THESE PRODUCTION SYSTEMS AS CHEMICAL SEED TREATMENTS ARE NOT ALLOWED. THIS PROJECT WILL BUILD UPON A PLANT BREEDING PARTNERSHIP BETWEEN WHEAT BREEDING PROGRAMS AT TWO FASE LAND-GRANT INSTITUTIONS TO ENHANCE GERMPLASM AND CULTIVAR DEVELOPMENT FOR RESISTANCE TO THE DWARF BUNT (T. CONTRAVERSA KUHN) AND COMMON BUNT (T. CARIES (D.C.) TUL. AND T. FOETIDA (WALLR.) LIRO) DISEASES. ENHANCED GENETIC RESISTANCE TO BOTH DISEASES WILL BENEFIT NOT ONLY ORGANIC WHEAT PRODUCTION IN THE UNITED STATES, BUT ALSO CONVENTIONAL WHEAT PRODUCTION IN DRYLAND FARMING REGIONS WORLDWIDE. THIS PROJECT WILL USE CURRENT GENOMICS TOOLS TO IDENTIFY CANDIDATE GENES AND TIGHTLY LINKED MOLECULAR MARKERS FOR MAJOR RESISTANCE GENES AND WILL DEVELOP A GENOMIC SELECTION SYSTEM FOR MINOR RESISTANCE GENES TO DWARF AND COMMON BUNT DISEASES. THE GENOMICS TOOLS EMPLOYED WILL INCLUDE QTL MAPPING WITH BI-PARENTAL AND GENOME-WIDE ASSOCIATION METHODS, HIGH- THROUGHPUT GENOTYPING PLATFORMS, AND TARGETED MUTAGENESIS (CRISPR-CAS9). THE INFORMATION GENERATED WILL ENABLE US TO OPTIMIZE A RESISTANCE SELECTION SCHEME BY COMBINING MARKER-ASSISTED SELECTION AND GENOMIC SELECTION METHODS AS PART OF OUR CULTIVAR DEVELOPMENT PROGRAM. THE GOAL OF THIS WORK IS TO DEVELOP DURABLE RESISTANCE TO THE TWO BUNT DISEASES BY STACKING MULTIPLE LARGE-EFFECT BT GENES WHILE SIMULTANEOUSLY ENHANCING QUANTITATIVE RESISTANCE IN ADAPTED GENETIC BACKGROUNDS. OUR PROJECT WILL THEREFORE ADDRESS THE PRIORITIES OF PROGRAM AREA CODE A1141 TO IMPROVE CROP PRODUCTIVITY AND EFFICIENCY, AND PARTICULARLY TO ENHANCE THE SUSTAINABILITY OF ORGANIC WHEAT PRODUCTION.