Cytogenetic characterization of Mimosa pudica L (Fabaceae): heterochromatin distribution, rDNA mapping and genome size

Chromosomal details and linear differentiation, including heterochromatin distribution, silver staining based characterization of NOR, delineation of chromomycin (CMA 3 ) and 4′,6-diamidino-2-phenylindole (DAPI) bands and FISH based localization of 45 S and 5 S rDNA sites are investigated for the first time for Mimosa pudica . All the three populations examined showed 2 n = 4 x = 52 with karyotype consisting of median and submedian chromosomes. However, Flow Cytometry based estimation of nuclear DNA amount revealed occurrence of polysomaty within the same tissue from roots, hypocotyls, cotyledons and epicotyls exhibiting DNA content amounting to 2 C, 4 and 8 C values. On the other hand, leaves showed cells with same DNA amount (2 C = 1.34pg). The CMA + / DAPI − banding and fluorescent in situ hybridization techniques revealed a unique coincident pair of chromosomes containing 45 S rDNA that was also detectible as Ag-NOR + . Two chromosomes showed one site of 5 S rDNA. The data presents new and important information for understanding karyotypic profile of Mimosa and Fabaceae.