**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** INCREASE OF FOOD PRODUCTION IS URGENTLY NEEDED TO FEED THE CONSTANTLY EXPANDING POPULATION. TOMATO IS ONE OF THE MOST CULTIVATED AND CONSUMED FRUIT CROPS WORLDWIDE, CONSUMED EITHER FRESH OR IN VARIOUS PROCESSED FORMS (E.G. PASTE, SAUCES). TOMATO IS ALSO THE MOST PROMINENT DIETARY SOURCE OF THE NUTRACEUTICAL LYCOPENE, VITAMIN C AND OTHER NUTRIENTS IN THE U.S. AND MANY COUNTRIES. DEVELOPMENT OF NOVEL STRATEGIES TO IMPROVE BOTH TOMATO FRUIT YIELD AND QUALITY ARE THUS OF UTMOST IMPORTANCE FOR FOOD AND NUTRITIONAL SECURITY. IN OUR PREVIOUS STUDY, WE FOUND THAT OVEREXPRESSION OF THE OR GENE NOT ONLY GREATLY INCREASES TOMATO FRUIT CAROTENOID CONTENT, BUT ALSO ENHANCES FRUIT SET AND TOTAL FRUIT YIELD. TO ELUCIDATE THE ROLES AND MECHANISMS AND TO DEVELOP BREEDING TOOLS, THREE SPECIFIC OBJECTIVES ARE PROPOSED: 1) TO GENERATE OR GENE MUTATIONS AND EXAMINE THE EFFECTS ON FRUIT SET AND YIELD; 2) TO ELUCIDATE HOW IT AFFECTS ON FRUIT SET, AND 3) TO ASSESS THE ASSOCIATION OF THE GENE EXPRESSION WITH FRUIT SET AND HEAT TOLERANCE IN A TOMATO DIVERSITY PANEL. THE PROPOSED RESEARCH IS EXPECTED TO CONTRIBUTE TO OUR FUNDAMENTAL UNDERSTANDING OF REPRODUCTIVE BIOLOGY AND INFORM BREEDING PROGRAMS TO GENERATE ELITE VARIETIES WITH IMPROVED YIELD ALONG WITH NUTRITIONAL QUALITY AND HEAT TOLERANCE IN CROPS BEYOND TOMATO.