Often, particularly in breeding programs attempting to use exotic germplasm to improve quantitative traits, the breeder needs to know which of several populations carry favorable alleles that are not present in elite germplasm. This knowledge would allow concentration of breeding efforts on a few populations where the probability of successful improvement of existing germplasm is relatively high. To provide this information, a method for identifying populations carrying favorable dominant alleles, not present in an elite single cross, is developed. In its simplest form, the method requires evaluation of the elite single cross, its inbred parents, and crosses of the populations to be evaluated to the two parents of the single cross. If the elite single cross is designated P1 ✕ P2, and the populations to be tested Py, the expression lp̄1μ = {[(P1 ✕ Py)• P1][(P1 ✕ P2) − P2] − [(P2 ✕ Py) − P2][P1 ✕ P2) − P1]}/2(P1 − P2) is an estimate of the product of the relative number of loci (lμ) not containing at least one favorable allele in P1 ✕ P2 and the average frequency of favorable alleles (p̄1) at such loci in Py. The method may be particularly useful for identifying populations of exotic germplasm which contain useful new alleles.