Karyotype polymorphism of GC-rich constitutive heterochromatin in Capsicum L. pepper accessions

Capsicum is represented by peppers and sweet peppers and comprises a group with remarkable genetic variability. Different cultivated Capsicum peppers of Brazil were evaluated by using CMA₃ and DAPI specific fluorochromes. There was high polymorphism of highly GC-rich CMA heterochromatic bands among the analyzed species, ranging from six (BAGC 114; C. annuum) to 26 blocks (BAGC 81; C. baccatum). Heterochromatin percentage ranged from 3.14% (BAGC 114; C. annuum) to 8.72% (BAGC 81; C. baccatum), corroborating the variation in the number of heterochromatic bands, particularly those distributed in the terminal and subterminal regions of the chromosomes. The information reported in this paper supports the cytogenetic characterization of the domesticated peppers accessions belonging to the Capsicum Germplasm Active Bank of the Federal University of Piauí (BAGC-UFPI). Moreover, the present data helped to better understand the karyotype features of peppers and provide additional information that could contribute to the improvement and maintenance of Capsicum genetic breeding programs.

Keywords:
CMA/DAPI staining; genetic diversity; genetic resources