Population and Quantitative Genetic Aspects of Molecular Breeding

Molecular breeding is defined as the application of molecular genetic tools to plant breeding. In this paper the application of population and quantitative genetics principles to plant breeding and the implications of those principles for the use of molecular genetic tools are discussed. The ability to transform plants and thus introduce genes from any species into a crop plant or to develop entirely new genes has greatly broadened the germplasm base for plant breeders. At the same time, this ability has created a set of problems, the solutions of which require application of population genetic theory. The availability of molecular markers has brought a rebirth of interest in quantitative genetics. It is now possible to identify chromosome segments which control quantitative traits and follow those traits in breeding. In addition, use of quantitative genetic principles provides a way of utilizing gene expression data as a plant breeding tool.