Technical Abstract: TILLING, targeting induced local lesions in genomes, combines conventional mutagenesis with targeted screening of known genes. Advantages are that a series of alleles can be recovered to assist with functional analysis, and mutations can be identified in polyploids where a phenotype is likely to be absent. Disadvantages of TILLING explicit to polyploids are that gene-specific primers must be designed to distinguish homeologs, and a phenotype is unlikely to be observed until mutations in homeologs are combined by crossing. A TILLING population has been generated in tetraploid peanut and screened for mutations in genes for allergenic proteins Ara h 1, Ara h 2, as well as the oil biosynthesis enzyme FAD2. Silencing of Ara h 2 by RNA interference has provided evidence that this protein and its related family member Ara h 6 may be dispensable for peanut seed growth, development, and viability. Therefore, recovery of knockout mutations in the two genes of Ara h 2 should allow elimination of this most severe allergen from peanut seed. Up to now potential knockout mutations in one copy each of Ara h 1, Ara h 2, and Fad2 have been identified and functional analysis is in progress.