Comparative Cytogenetics and Fluorescent Chromosome Banding in Five Indian Species of Medik.

The genus Medik. (Subfamily: Scilloideae) has a narrow distribution in India and several overlapping morphological traits make the genus taxonomically challenging at the species level. Cytogenetic characterization can provide additional taxonomic data and can be used to evaluate genetic diversity at the species level. We have accomplished comparative karyotype analysis and fluorescence banding patterns using 4'-6-Diamidino-2-phenylindole (DAPI) and Chromomycin A (CMA) in five Indian species for the first time. The karyotypes of and exhibited similar fluorochrome banding profiles. However, , differ distinctly in their karyotypes. In all taxa, CMA/DAPI or DAPI (GC-rich) constitutive heterochromatin was located at the constriction region or terminal satellite of the nucleolar chromosome. DAPI/CMA or CMA (AT-rich) heterochromatin dominates in . However, shows a distinct variation in fluorochrome banding pattern from all other species. The distribution of CMA and DAPI bands is a reflection of heterochromatin composition and variations acquired by different species. This characterization can be used to assess phylogenetic relationships in the understudied genus and may serve as a basis for other genomic analyses and evolutionary studies.