CYTOGENETIC STUDIES IN THE GENUS HORDEUM: I. CHROMOSOME MORPHOLOGY

Abstract

The morphology of the chromosomes of 16 Hordeum species was studied in considerable detail. No obvious trend in evolution is apparent from a study of the karyotypes of the species nor are any definite relationships with common barley (H. vulgare) indicated, except for two species, usually considered as being related, H. spontaneum and H. agriocrithon. On the basis of similarities of karyotype and morphological features of the plants seven groups were formed in which relationships are evident. The groups are: vulgare, marinum, murinum, californicum, stenostachys-pusillum, bulbosum, and jubatum. The plants within each group are identified by assigned numbers and by the specific names under which they were received. Within these groups are chromosome numbers of 14 and 28 and in one case 28 and 42. Allopolyploidy is indicated for most groups but H. bulbosum exists both as a diploid and as an autotetraploid.