Cytogenetic Studies of Hybrids between <em>Festuca gigantea</em> Vill. and <em>Lolium multiflorum</em> Lam.

The meiotic behaviour of the hybrid between Festuca gigantea (2n - 6x = 42) and Festuca arundinacea (2n = 6x = 42) indicates distinct structural differences between the two species. These differences are also apparent in the degree of chromosome pairing observed in Lolium multiflorum &#215; F. gigantea compared with previous reports on the L. multiflorum &#215; F. arundinacea hybrids. Although the L. multiflorum &#215; F. gigantea 8x amphiploid combines the complementary characters of the two species and is agronomically interesting, there are some irregularities in meiotic behaviour that could affect the stability of the amphiploid. Seed fertility in the amphiploid is high and preliminary studies show evidence of a high degree of self-fertility. The pentaploid hybrid between autotetraploic L. multiflorum &#215; F. gigantea is sufficiently fertile to be used as the pollen plant in crosses with diploid L. multiflorum (BC[Sub1]. Backcrossing the BC[Sub1] hybrid to L. multiflorum results in mainly diploid progeny. The possibilities of using this crossing scheme to introgress F. gigantea characters into L. multiflorum is discussed as an alternative approach to amphiploid breeding as a means of combining specific complementary characters of the two species. [ABSTRACT FROM AUTHOR]