Evolutionary Relationships between Two South American Species of Hordeum

Abstract

The morphology, meiotic behavior and karyotypes of Hordeum halophilum, H. muticum and of the natural interspecific sterile hybrid have been studied. Evidence from meiotic behavior in the hybrid as well as the study of the karyotype in both diploid species indicates that their genomes are largely homologous. They differ, however, in at least one reciprocal translocation and one paracentric inversion. The isolating mechanisms between both species and the formation of dineocentric bridges at second anaphase are discussed.