Genome relationships between eight diploid Hordeum species

Abstract

The eight species included in Hordeum section Anisolepis s. lat., viz. H. pusillum Nutt., H. intercedens Nevski, H. euclaston Steud., H. flexuosum Nees, H. muticum Presl, H. cordobense Bothm. et al., H. stenostachys Godr., and H. chilense Roem. et Schult. were intercrossed in all combinations in order to study the relationships between them. In two combinations, a segregating F2 generation was obtained, otherwise there were strict sterility barriers among the taxa. The meiotic studies revealed that all species have homoto homoeologous chromosome sets, i. e. they have the same ‘basic genome’. Any variation in pairing and occurrence of multivalents was interpreted as indicating that certain populations had undergone structural cytological changes, as these events were not linked to specific taxa. No cytogenetic evidence obtained indicated that some species were more closely related than others.