Studies on species hybrids in Aegilops were undertaken by BLEIER (1928) for the first time since the right chromosome numbers of the genus was established, and from that time many papers have been published on this subject. 21 species of Aegilops, including 9 diploid analyzers, have been studied on the basis of genome analysis by KIHARA and his collaborators. From among 210 possible combinations of species hybrids, 104 combinations have already been made and they have been cytologically studied by many cytogeneticists of the world as given in the following table.
All the possible and successful combinations of species hybrids are tabulated on the facing attached page.