Karyotype analysis and report on B-chromosome in Gloriosa superba L. by differential staining

Abstract

In this investigation Gloriosa superba L. was cytogenetically studied with orcein, CMA and DAPI-staining for authentic characterization. “Complex Chromocenter Type” of interphase nuclei with 3–4 bigger darkly stained heterochromatic regions was found in this species. The prophase chromosomes were “Interstitial Type” with darkly stained region at different interstitial sites of chromosomes. This species had 2n = 22 chromosomes with heterogenous centromeric formulae 14 m + 8 sm. In addition to the regular chromosomes, 1–6 small chromosomes were found in several mitotic pro-metaphase, metaphase and anaphase stage which covered 43.57% of the total cell count of this species suggesting the probable occurrence of B-chromosome. Presence of B-chromosome was probably the first report for this genus. After fluorescent banding, a pair of dot like CMA fluoresced bands were observed whereas no bright band was found in G. superba after DAPI-staining which suggested the coexistence of GC- and AT-base pairs in the genome. Thus, the compilation of the above information will be very useful for cytogenetical characterization of G. superba L. in Bangladesh.