**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** COTTON PRODUCTION ACROSS THE UNITED STATES IS UNDER SERIOUS THREAT FROM A SOIL-INHABITING, DENSITY DEPENDENT FUNGUS, CALLED FUSARIUM OXYSPORUM F. SP. VASINFECTUM RACE 4 (FOV4), WHICH CAUSES FUSARIUM WILT. LEFT UNCHECKED, FOV4 COULD DECIMATE THE ENTIRE COTTON GROWING INDUSTRY IN THE UNITED STATES. THE LONG-TERM GOALS OF THIS PROJECT ARE TO DEVELOP AND UTILIZE ADVANCED GENETIC AND BREEDING TOOLS THAT LEAD TO: 1) A COMPREHENSIVE UNDERSTANDING OF THE GENETIC ARCHITECTURE UNDERLYING RESISTANCE TO FOV4 (QTLS AND FUNCTIONAL ALLELES); 2) APPLIED APPROACHES TO TRACK AND PREDICT RESISTANCE IN UPLAND COTTON GERMPLASM AND BREEDING PIPELINES; 3) DELIVERY OF RESISTANT GERMPLASM TO ALLIED SCIENTISTS, COTTON BREEDERS, AND GROWERS WITH IMPROVED YIELD AND DESIRABLE AGRONOMIC CHARACTERISTICS FOR CONTINUED AND SUSTAINABLE COTTON PRODUCTION. OUR RESEARCH TEAM HAS EFFECTIVELY SCREENED OVER 5,000 UPLAND LINES AND IDENTIFIED 2 SOURCES OF DURABLE GENETIC RESISTANCE AND PUBLICLY RELEASED THE ONLY HIGHLY RESISTANT UPLAND LINE, U1, FOR USE IN BREEDING PIPELINES. WE HAVE DEVELOPED F7 RILS FROM 3 BIPARENTAL MAPPING FAMILIES AND PROPOSE TO CONDUCT HIGH-RESOLUTION GENETIC MAPPING TO DEVELOP DIAGNOSTIC BIOMARKERS FOR MOLECULAR BREEDING ENHANCEMENT. WE WILL IDENTIFY AND RELEASE NEW AND IMPROVED FOV4 RESISTANT GERMPLASM AND WILL IDENTIFY CANDIDATE GENES FOR THEIR ROLE IN RESISTANCE. THIS WILL ESTABLISH A FOUNDATION FOR GENOME ENGINEERING FOR BIOTIC RESILIENCE FOR THE FUTURE OF COTTON PRODUCTION.