CHARACTERIZATION OF THE LATE REPLICATION BANDING-PATTERNS IN BARLEY CHROMOSOMES

Replicating DNA regions on barley chromosomes were investigated by a r eplication banding technique. Of all chromosomal regions, the late rep licating regions, in which DNA replicated in the last third of S phase , were detected as exceptionally distinct bands. Each late replicating region had its own timing and duration to replicate, which were not i nfluenced by any translocations. This suggested that the late replicat ion was highly associated with the structure of its related chromosoma l region. By using the series of translocated chromosome lines, the la te replication banding patterns of seven barley chromosomes were ident ified. The late replication banding pattern was similar to the C-bandi ng pattern. The relationships of the late replicating regions with het erochromatin and C-banding regions are also discussed.