In the maize community, successful breeding programs depend on adequate diversity in maize germplasm. However, diversity itself is lost during the generation of advanced breeding stocks and materials. For many crop species, diversity in breeding programs has reached a point of diminishing returns. If the climate turns adverse, for instance, it is feared that we may face catastrophic reductions in crop productivity unless new diversity is infused into the breeding germplasm.
Transgenic approaches have been proposed and used in breeding programs for the purpose of infusing genetic diversity into the breeding germplasm. These approaches are largely based on quantitative trait loci genetics and are either highly laborious processes or inefficiently discover relevant variation.
Mutant-Assisted Gene Identification and Characterization (MAGIC) is a "back to nature" approach to genetic diversity that may prove faster and more efficient than transgenic approaches. Wild and exotic relatives of crop plants hold a wealth of alleles that can help break yield barriers and enhance tolerance to stresses. But they must be found effectively and efficiently. MAGIC is a gene-centered approach that uses Mendelian mutants (or other genetic variants in a trait of interest) as reporters to identify novel genes and variants for traits of interest. MAGIC is similar to enhancer-suppressor screens. However, rather than relying on variation created in the laboratory MAGIC reveals variation created and refined by nature over millions of years of evolution.
The MAGIC approach has been shown to be a viable approach for identifying naturally occuring useful genetic variation. That is, MAGIC could prove to be an effective tool for exploring novel variation as well as a valuable means to harness natural diversity and to define genetic networks.