STUDIES ON GIEMSA C-BANDS AND CHROMOCENTERS OF SILPHIUM PERFOLIATUM

Somatic chromosomes (2n=14) of root-tip cells of Silphium perfoliatum were treated with Giemsa C-banding procedure, All centromeres and the telomeres of short arms of the 5th and the 7th chromosomes have stable C-bands, There are two strong intercalary C-bands on the long arms of the 6th chromosomes, and other intercalary bands are weak and very unstable, A chromosome complement in interphase nuclei arranges in a well-known Rable configuration On the polar where centromeres assemble in interphase nuclei have 20 chromocenters maximally. Statistical analysis reveals, by counting chromocenter number. that the heterochromatin fusion in interphase is non-ramdon. The heterochromatiu at the short arm telomeres of the 5th and the 7th chromosomes as well as one of the two intercalary bands on the long arm of the 6th chromosomes which are all located near the centromeres, have a tendency to fuse with the centromere heterochromatin, The maximal number of chromocenters on the centromere-assembled polar of an interphase nucleus is equal to the number of C-bands of a metaphase chromosome complement