Dikaryon is a stage/phase of a cell, in which, there are two nuclei.This condition arises, if fusion of cytoplasm (plasmogamy) is not immediately followed by fusion of nuclei (karyogamy), i.e., there is a delay between them.Such cells are called dikaryotic cells.This condition is found in higher fungi where karyogamy is delayed (with respect to plasmogamy) and is called dikaryophase.