Results showed that its resistance to CYR18 and 2E16 are all controlled by three recessive complementary genes, and the results of reciprocal crosses were the same, indicating that the resistance is inherited by nucleus.
Seedling resistance identification showed that there were three recessive complementary genes in Early Premium controlling resistance to 2E16.
Second, and more important, we assume that speciation results from the accumulation of complementary genes and not from "peak shifts" or "transilience events." In short, here as elsewhere (Orr 1995; Turelli and Orr 1995), we attempt to work out the theoretical consequences of the recent experimental findings in the genetics of speciation - findings that strongly suggest that postzygotic isolation results from the fixation of genes having no deleterious effects on their normal genetic backgrounds.
For similar reasons, we believe one must remain skeptical of all theoretical claims about speciation that do not explicitly take into account the mechanism by which hybrid sterility and inviability arise, the accumulation of complementary genes. Although reproductive isolation is almost certainly an "epiphenomenon" of divergence by ordinary population genetic processes, it does not follow that the mathematics describing speciation are identical to those describing divergence under natural selection or genetic drift.
Complementary gene interactions are, of course, well known: in Drosophila melanogaster, for instance, many mutations that are viable "by themselves" are lethal when combined, e.g., pn and Killer-of-pn (Sturtevant 1956).
Identification and recombination of
complementary genes at different loci can enable breeders to intentionally construct a phenotype that would not be the predicted outcome of a cross (based on the phenotypes of the parents; Xu, 1989; Xu and Shen, 1992b).
