Karyomorphology of Justicia Adhatoda L. by differential staining

Abstract

Karyomorphological features of Justicia adhatoda L. were investigated in this
study after differential staining with orcein, CMA and DAPI for proper
characterization. In this species "Simple Chromocenter Type" of interphase nuclei
was observed with many small heterochromatin blocks after orcein staining.
Prophase chromosomes showed "Interstitial Type" of staining pattern which
indicated the tendency of aggregation of heterochromatin in interstitial regions
of chromosome. This species was found to possess 2n = 34 metacentric
chromosomes. The total length of 2n chromosome complement was 132.17 μm.
Individual chromosome length ranged from 2.57 to 5.43 μm. The relative length
of each chromosome ranged from 0.02 to 0.04. A total of seven CMA-positive
bands were observed in this species whereas no band was found after DAPIstaining.
This result suggested the absence of AT-rich portions and occurrence of
GC-rich portions in the respective banded chromosomes. Except 2n chromosome
number, the other karyological and fluorescent banding information probably
was the first report for this species and it might help to enhance the
chromosomal data base with detailed karyomorphological information of this
plant species in Bangladesh.