Some artificial intergeneric hybrids in the Triticeae.

By culturing hybrid embryos in vitro, the following F1 hybrids could be achieved: (1) Triticum ovatum x Elymus arenariusy (2) Hordeum vulgare x E. arenarius, (3) E. are narius x Secale cereale, (4) Roegneria mutabilis x 5. cerealey (5) R. borealis x S. cereale. A monoploid plant of E. arenarius was obtained from the cross E. arenarius x H. vul gare (2a), obviously through somatic elimination of the barley chromosomes. The meiosis of hybrid No. 5 was studied cytologically, and found to be very disturbed. The pseudomeiotic course of the divisions is described and illustrated. Some theoretical aspects of meiosis are discussed in the light of previous research and the present ob servations. Studies on monoploids and on hybrids between the other species of these genera are briefly reviewed. The possible value of such hybrids in plant breeding is discussed.