串叶松香草Giemsa C带和染色中心研究

以Giemsa C带技术处理串叶松香草根尖细胞染色体(2n=14),全部着丝点及第5和第7对染色体短臂端部显稳定的C带,第6对染色体长臂有两条明显的居间带,其他居间带小而不稳定(重复率不高)。间期细胞核染色体呈Rable构型,其着丝点一极最多出现20个染色中心。统计分析表明,靠近着丝点的短臂端带区和居间带区异染色质有易与着丝点区异染色质融合的倾向。分裂中期Giemsa C带数目与间期染色中心数目存在数量对应关系。

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