In recent years, genetics and genomics has played an important role in facilitating the genetic improvement of plants. Different tools have been developed to examine the structure, function, and properties of genes controlling complex traits. The genetic diversity of germplasm found in existing gene banks through different breeding populations such as core collections, nested association mapping panels, mutants, recombinant inbred lines, and multiparent advance generation intercross populations in germplasm banks served as sources of desirable alleles for plant breeding.