Differential staining of two forms of Datura metel L.

Two forms of Datura metel L., one having single whorled and the other with double whorled corolla possessed 2n = 24 metacentric chromosomes. The chara cteristics of the orcein stained interphase nuclei and prophase chromosomes indicated the existence of facultative heterochromatin in the double whorl ed variety. One chromosome showed a CMA-positive interstitial band and anot her, a centromeric band in the single whorled form whereas only one CMA-pos itive interstitial band appeared in the double whorled form. The size and t he location of The CMA-positive interstitial bands were similar in the two forms. In interphase nuclei, two CMA-positive dots were found in the single whorled form and one in the double whorled form. The two varieties showed different activities for acid phosphatase. Thus, CMA-banding pattern and is oenzyme properties of the two forms are indicative of their distinct variet al status.