Hybrids of Hordeum californicum and 2x H. brevisubulatum s.l. with Agropyron caninum

Abstract

Two diploid Hordeum species, H. californicum (2n=2x=14) and H. brevisubulatum s.l. (2n=2x=14), were used successfully to produce hybrids with Agropyron caninum (2n=4x=28) through embryo rescue techniques. The floral morphology of the hybrids was intermediate between the parents in each case. Both hybrids were triploids (2n=3x=21), and chromosome pairing exhibited a mean of 3.86 bivalents in the hybrid with H. californicum and a mean of 5.53 bivalents in the hybrid with H. brevisubulatum. Bivalent formation was attributed to a common genome between the diploid Hordeum species and the tetraploid A. caninum. It could not be ascertained whether the difference in the two hybrids was due to a difference in the degree of homology or difference in meiotic control mechanisms.