Analysis of karyotype and C-banding pattern ofNicotiana plumbaginifolia using two techniques

The morphological study of the chromosomes ofNicotiana plumbaginifolia was carried out using two karyological techniques referred to as the squash method and the protoplast method. The latter involves isolation of protoplasts from unfixed root meristems and provides mitotic images in which the chromosomes, conveniently dispersed and disposed on the same plane, are significantly longer, and better structured, than those obtained by the squash method. A critical analysis of this technique is carried out. The results of this study led us to propose a karyotype forNicotiana plumbaginifolia and to characterize each chromosome by mere morphological examination. This characterization was further detailed by C-banding.