**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** WISCONSIN IS THE WORLD EPICENTER OF CRANBERRY (VACCINIUM MACROCARPON AIT.) PRODUCTION. PRESENTLY, THE VERY FEW VARIETIES THAT EXIST IN THE MARKET ARE VERY SIMILAR GENETICALLY, OWING TO THEIR LOW GENETIC DIVERSITY, RESULTING FROM A FEW NATIVE SELECTIONS AND FIRST-GENERATION HYBRIDS. WITH UNPREDICTABLE ENVIRONMENTAL CLIMATIC SHIFTS AND A NARROW GENETIC BASE OF MODERN CRANBERRY CULTIVARS, THE INDUSTRY HINGES ON PRESERVING AND USING GENETIC DIVERSITY DURING BREEDING TO CREATE THE ECONOMIC VIABILITY NEEDED IN THE FUTURE. THIS PROJECT WILL STUDY A GENETICALLY DIVERSE CRANBERRY COLLECTION (N=353), AND OUR RESEARCH WILL REINVIGORATE LONG TERM CRANBERRY BREEDING PROGRAMS BY IDENTIFYING FAVORABLE GENES FOR FRUIT QUALITY. DUE TO THE HIGH DEMAND FOR SWEETENED DRIED CRANBERRIES (SDC) AND LOW VALUE FOR JUICE CONCENTRATE, THERE IS A CURRENT NEED TO FOCUS ON FRUIT QUALITY WITH AN EMPHASIS ON FRUIT FIRMNESS, SIZE, AND UNIFORMITY, ANTHOCYANIN, ACID AND SUGAR CONTENT, AND SOUND YIELD. BY EVALUATING DIVERSE GERMPLASM FOR TRAITS OF INTEREST TO CRANBERRY BREEDERS AND GROWERS, WE WILL PROVIDE NEW KNOWLEDGE OF THE GENETIC ARCHITECTURE OF IMPORTANT TRAITS FROM WHICH SUITABLE BREEDING STRATEGIES AND PHENOTYPING METHODS CAN BE EMPLOYED TO EFFICIENTLY CREATE NEW CRANBERRY VARIETIES. THIS RESEARCH WILL HELP CRANBERRY BREEDERS PROTECT CRANBERRY GROWERS BY INCREASING FRUIT QUALITY WHILE MAINTAINING GENETIC DIVERSITY, WHICH MAY BE NEEDED IN THE FUTURE TO AVOID DEVASTATING LOSSES BY PROVIDING VARIETIES WITH HIGH FRUIT QUALITY THAT HOLD UP IN THE FACE OF ADVERSITY.THIS RESEARCH WILL LEVERAGE THE GENOTYPING PLATFORM 'CAPTURESEQ', WHICH WAS DEVELOPED THROUGH THE VACCINIUMCAP PROJECT: LEVERAGING GENETIC AND GENOMIC RESOURCES TO ENABLE DEVELOPMENT OF BLUEBERRY AND CRANBERRY CULTIVARS WITH IMPROVED FRUIT QUALITY ATTRIBUTES (USDA NIFA PROJECT NO. 2019-51181-30015). WE WILL GENOTYPE THE DIVERSITY PANEL BY LEVERAGING THE ~20,000 CAPTURE-SEQ BASED SNP (SINGLE NUCLEOTIDE POLYMORPHIC) MARKERS.WE WILL COLLECT TRAIT DATA USING A HIGH-THROUGHPUT PHENOTYPING METHOD TO ASSESS FRUIT QUALITY AND FLAVOR TRAITS SUCH AS TITRATABLE ACIDITY, SUGAR CONTENT, COLOR, FRUIT SIZE, AND FRUIT SHAPE. USING THE PHENOTYPIC DATA AND GENOTYPIC DATA TOGETHER, WE WILL LEVERAGE STATISTICAL METHODS TO CALCULATE TRAIT HERITABILITY IN ORDER TO LEARN ABOUT THE PROPORTION OF TRAIT VARIATION THAT IS ATTRIBUTABLE TO GENETIC VARIATION, AND PERFORM GENOME WIDE ASSOCIATION STUDIES (GWAS), IN ORDER TO IDENTIFY GENOMIC REGIONS ASSOCIATED WITH FRUIT QUALITY AND FLAVOR TRAITS. THIS PROCEDURE WILL HELP TO IDENTIFY CRANBERRY LINES THAT CARRY FAVORABLE ALLELES, WHICH CAN BE USED AS PARENTS IN A BREEDING PROGRAM. IDENTIFICATION OF TRAIT-LINKED MARKERS WILL ASSIST IN EFFICIENT INTRODUCTION OF FAVORABLE ALLELES INTO NEW GENETIC BACKGROUNDS.WE PLAN TO VISIT CIRCUMBOREAL FORESTS TO CONDUCT CRANBERRY PLANT PROPAGULE COLLECTION, WITH A GOAL OF EXPANDING THE USDA-ARS CRANBERRY COLLECTION BY 25%. THERE ARE APPROXIMATELY 50 NATIONAL SITES WHERE CRANBERRIES ARE CURRENTLY GROWING IN THE WILD WITHOUT HUMAN ASSISTANCE, WE WILL VISIT THE SITES WITH THE MOST GENETICALLY DIVERSE POPULATIONS, CHARACTERIZE THE TOPOGRAPHY, LOCAL VEGETATION, SOIL, INTEGRATE GIS DATA, WEATHER DATA, SATELLITE IMAGE DATA, AND USE ALL AVAILABLE DATA TO FORMULATE HYPOTHESES ABOUT THE GENETIC MERIT AND CHARACTERISTICS OF THESE SPECIMEN BASED ON THE ENVIRONMENT IN WHICH THEY ARE THRIVING. WE WILL BRING LIVE SPECIMENS TO CONTRIBUTE TO THE GENETIC DIVERSITY OF THE COLLECTION, PERFORM TISSUE (DNA) COLLECTION AND GENOTYPING, CONDUCT IN-SITU PHENOTYPING (E.G., PLANT ARCHITECTURE, FLOWERING, FRUIT QUALITY, ETC.). DNA SAMPLING AND SEQUENCING OF COLLECTED PLANTS WILL LAY THE GROUNDWORK FOR FUTURE GENETIC STUDIES AND IDENTIFICATION OF NOVEL TRAITS AND ALLELES. PROPAGULES WILL BE HOUSED BOTH WITH THE USDA-ARS COLLECTION AT THE UW-MADISON CRANBERRY BREEDING GENOMICS LAB AND AT THE NATIONAL CLONAL GERMPLASM REPOSITORY IN CORVALLIS OREGON.WE BELIEVE THAT THE SUCCESS OF THIS RESEARCH LIES IN THE WISCONSIN IDEA - THAT THE RESEARCH AND THE WORK OF THE UNIVERSITY OUGHT TO BENEFIT PEOPLE BEYOND THE WALLS OF OUR CAMPUS. NOWHERE IS THIS MORE RELEVANT THAN OUR DIRECT WORK WITH OUR FARMERS AND STAKEHOLDER GROUPS. WHILE CRANBERRY IS AN ECONOMICALLY IMPORTANT CROP IN THE STATE OF WISCONSIN, CRANBERRY GROWERS IN OUR STATE FACE CONDITIONS THAT CURRENT VARIETIES ARE NOT ADAPTED TO. AS THE NEEDS OF GROWERS CHANGE IN AN UNPREDICTABLE CLIMATE, IT IS NECESSARY FOR BREEDERS TO DEVELOP CULTIVARS WITH TRAITS THAT MAY NOT BE PRESENT IN THE MOST POPULAR CULTIVARS USED TODAY. THROUGH CONSERVATION AND USE OF THESE CRANBERRY GENETIC RESOURCES, BREEDERS MAY USE WILD POPULATIONS AND DERIVED GERMPLASM COLLECTIONS AS GENETIC POOLS FOR THE INTRODUCTION OF USEFUL TRAITS