DURING THE LONG-TERM IMPROVEMENT PROCESSES IN MAIZE, LARGE NUMBERS OF BAD ALLELES HAVE BEEN ACCUMULATED AND FIXED IN THE ELITE MAIZE LINES BY CHANCE, CREATING OBSTACLES FOR FURTHER CROP IMPROVEMENT. FORTUNATELY, A PORTION OF THE FIXED BAD ALLELES ARE STILL SEGREGATING IN TRADITIONAL CULTIVATED LANDRACES, WHICH PROVIDES OPPORTUNITIES TO RESCUE THESE FIXED BAD ALLELES AND TO ENRICH THE DIVERSITY OF THE GERMPLASM POOL FOR BREEDING. IT WILL TAKE YEARS, HOWEVER, TO ADAPT THE OPEN POLLINATED LANDRACES, MAINLY GROWN IN THE TROPICAL AREAS OF THE WORLD, TO THE U.S. CORN BELT ENVIRONMENTS. THE USDA-ARS GEM (GERMPLASM ENHANCEMENT OF MAIZE) PROJECT HAS BROUGHT SOME OF THE EXOTIC ALLELES INTO TEMPERATE LINES SINCE 1994. IN THIS PROJECT, WE WILL IDENTIFY THE ALTERNATIVE ALLELES USING PUBLICLY AVAILABLE GEM LINES AND EVALUATE THEIR PHENOTYPIC CONSEQUENCES, EMPHASIZING ON THE MICRONUTRIENT COMPOSITION AND YIELD RELATED TRAITS. WE WILL BACKCROSS THE PROMISING GEM LINES CARRYING GOOD ALLELES WITH THE ELITE MAIZE LINES AND CONDUCT GENOMIC SELECTION (GS) OVER SEVERAL CYCLES. IN THIS PROJECT, AN ADVANCED GS PROTOCOL WILL BE DEVELOPED. AT THE END OF THE PROJECT, A SOFTWARE PACKAGE WILL BECOME PUBLICLY AVAILABLE FOR CONDUCTING BIOLOGICAL INFORMED GS. A SET OF ENHANCED PRE-BREEDING MATERIALS WILL ALSO BE RELEASED, ENABLING THE CONTINUOUS GENETIC IMPROVEMENTS AND THE SUSTAINABILITY OF U.S. AGRICULTURE.