Abstract
Calliandra is a neotropical genus composed of 139 species with distribution in North, Central and South America. In this work, a comparative cytogenetic analysis of 10 species of the Androcallis section was performed by double staining with base-specific chromomycin A3 (CMA) and 4′,6-diamidino-2-phenylindole (DAPI). The DNA content of the species was also estimated by flow cytometry. This study revealed that the species C. macrocalyx, C. riparia, C. imperialis, C. ulei, C. spinosa and C. umbellifera are diploid with 2n = 2x = 16, C. fernandesii is tetraploid with 2n = 4x = 32, C. sessilis is octaploid with 2n = 8x = 64 and C. dysantha is decaploid with 2n = 10x = 80. This result revealed that polyploidy is one of the recurrent cytogenetic events in the evolution of the genus Calliandra. As for the number of CMA+ bands, it was possible to characterize each species. No AT-rich DAPI band was located on the chromosomes of the species. The results suggest that chromosomal rearrangements and polyploidy contributed to the evolution of Calliandra species, as demonstrated by the cytotaxonomic characterization in the genus.
Acknowledgements
We thank the Graduate Program in Botany and the Department of Biology of the Federal Rural University of Pernambuco (UFRPE) and the Federal University of Pernambuco (UFPE) for allowing the use of the Cytogenetics and Plant Evolution Laboratory for the flow cytometry analyses.
Disclosure statement
No potential conflict of interest was reported by the authors.