** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** IDEOTYPE BREEDING DURING THE GREEN REVOLUTION OF THE MID-20TH CENTURY CREATED THE FIRST-GENERATION HIGH-YIELDING RICE CULTIVARS WITH HIGH PRODUCTIVITY UNDERUNPOLLUTED ENVIRONMENTS, WITH AMPLE SUPPLY OF CLEANWATER FOR IRRIGATION AND NUTRIENTS FROM INORGANIC FERTILIZERS.THIS APPROACH IS BASED ON THE PARADIGM OF STACKINGINDIVIDUAL MORPHOLOGICAL AND PHYSIOLOGICAL TRAITS THAT ACT SYNERGISTICALLY TO CREATE A PLANT ARCHITECTURE THAT FUNCTIONS OPTIMALLY UNDER CERTAIN ENVIRONMENTS FOR MAXIMAL YIELD.IN THE 21ST CENTURY, THE CHALLENGE TO FOOD SECURITY IS MUCH GRANDER THANDURING THE GREEN REVOLUTION AS MORE FOODS NEED TO BE PRODUCED UNDER STEADILYMARGINALIZING ENVIRONMENTS AND CHANGING CLIMATE. NEW REALITIES SURROUNDING THE CHANGING GLOBAL ECOLOGICAL DYNAMICS AND LIMITING RESOURCESPAINTA NEW PICTURE OF THE MUCH GRANDER CHALLENGES AHEAD THATREQUIRE BOLDER YET PRAGMATIC NEW APPROACHES FOR CROP BREEDING. NEW TECHNOLOGIES ARE NEEDED TO RE-OPTIMIZE THE GROWTH, MORPHOLOGY, PHYSIOLOGY AND REPRODUCTION OF CROP PLANTS TO MAINTAIN YIELD UNDERLESS IDEAL ENVIRONMENTS AND LIMITED NATURAL RESOURCES.USING A MODERN ANDINTEGRARIVE APPROACHTO THE DISSECTION OF THE GENETIC AND PHYSIOLOGICAL BASES OF TRAITS, THIS PROJECT TAKES A MUCH DEEPER LOOK ON THE CLASSIC GENETIC PHENOMENON OF TRANSGRESSIVE SEGREGATION IN PLANTS. THIS PHENOMENON WILL BE USEDAS THE CORE COMPONENT OF A HOLISTIC STRATEGY TO CREATENOVEL IDEOTYPESFOR THE NEXT-GENERATION OF RICE CULTIVARS WITH ROBUSTYIELD UNDER ENVIRONMENTS AFFECTED BY SALINITY AND MARGINALIZED WATER RESOURCES. TRANSGRESSIVE SEGREGATION OCCURS WHEN A SMALL MINORITY OF PROGENIES DERIVED FROM THE MATING OF TWO GENETICALLY WIDELY CONTRASTINGPARENTS EXHIBIT TRAITS THAT ARE EITHER SUPERIOR TO THE BETTER OF THE TWO PARENTS OR INFERIOR TO THE WORSE OF THE TWO PARENTS.THIS PROJECT WILL ELUCIDATE THE GENETIC AND PHYSIOLOGICAL UNDERPINNINGS BEHIND THE NON-PARENTAL SUPER-TOLERANCE (POSITIVE TRANSGRESSIVE) OR SUPER-SENSITIVITY (NEGATIVE TRANSGRESSIVE) TO SALINITY ACROSS THE ADVANCED GENERATION PROGENIES OFIR29 (INDICA) X POKKALI (AUS) RICE, BEYOND THE EFFECTS OF THE KNOWN MAJOR DEFENSE MECHANISM THAT WASDEPLOYED INTO CULTIVARS BYBREEDING DURING THE LAST FOUR DECADES. THIS PROJECT SEEKS TO REVEAL THE GENETIC AND PHYSIOLOGICAL CAUSES OF THE ADAPTIVE NOVELTIES OF TRANSGRESSIVE SEGREGANTS UNDER SALINITY STRESS, WHICH COULD CREATE IDEOTYPES THAT ARE FAR BETTER THAN THE SUPERIOR PARENT (NET GENETIC GAIN) OR FAR WORSE THAN THE INFERIOR PARENT (NET GENETIC PENALTY). THE SPECIFIC OBJECTIVES OF THE PROPOSED PROJECT WILL BE ACCOMPLISHED BY A COMPREHENSIVEAND INTEGRATIVE APPROACH TO GENETICSTHAT INCLUDES DIGITAL ANALYSIS OF PLANT GROWTH, DEVELOPMENT, AND MORPHOLOGY, PROFILING OF THE CHANGES IN GENE EXPRESSION, AND ANALYSIS OF GENE FUNCTION BYTRANSGENICS AND GENE EDITING.