Differential fluorescent banding patterns in three varieties of pea (Pisum sativum L.)

The karyotypes of three varieties of Pisum sativum viz. Local (BR-1), Indian and Japanese (2n =14) were compared after differential staining with Orcein, CMA and DAPI. The Local variety possessed complex chromocenter type of interphase nuclei and interstitial type of prophase chromosomes. In contrast, the Indian and Japanese variety had diffuse type of interphase nuclei and continuous type of prophase chromosomes. A number of fragments that look like B-chromosomes were observed in all these varieties. Satellite was observed only in the Indian variety in CMA and DAPI-staining. BR-1 possessed eight CMA-positive bands in eight chromosomes one in each. In the Indian variety, two CMA-positive bands found in the interphase, prophase and metaphase were the Nucleolus Organizer Regions (NOR). No CMA-band was found in the Japanese variety, It means that later variety was lack of GC-rich base sequences. Presence of CMA-and DAPI-positive bands at the centromeric regions of the local variety indicated the co-existence of GC-and AT-rich sequences at those regions. Thus the three varieties of P. sativum could be distinguished by differential fluorescent banding techniques.