Wheat diversity surveys are important for gaining genomic insights into its architecture and yield improvement. In this talk, we will report our work to exome sequence 287 wheat accessions that formed Chinese wheat mini-core collection generated from 23,000 accessions. By population genetics analysis, we identified 6.7% of the wheat genome that fell within the selective sweeps between landraces and cultivars. These genomic regions harbored genes known for yield improvement that were asymmetrically distributed among wheat subgenomes. Regulatory genes on A and B subgenomes were favorably selected. Genome-wide association study (GWAS) identified genomic loci associated with traits for yield potential. We functionally studied genes underlying two such genomic loci, an auxin response factor TaARF12 and the rice DEP1 ortholog TaDEP1, which regulated both plant height and grain weight. Further elite single-nucleotide haplotype analysis found alleles with increased frequency in cultivars relative to the landraces that were accumulated over the course of breeding, many of which were involved in multiple traits. Moreover, these pleiotropic loci interacted additively with the classical Rht-1 locus for plant height, but interacted epistatically for grain yield. These findings suggest a "Green Revolution"-based model for historical wheat breeding. Recent progress about further functional study of yield related genes will be reported.