“…Within certain limits, the amount of heterochromatin is not critical to genome function but in a few species it is enormously expanded, forming large heterochromatic blocks, as in Trithrinax campestris and Capsicum species (Gaiero et al, 2012;Grabiele et al, 2018), or numerous small bands, as in Cuscuta monogyna (Ibiapino et al, 2020). The tandemly repeated nature of rDNA and telomeric DNA sites allows a considerable variation in number and size of these sites, contributing to a better karyotype characterization of species or populations (Pedrosa-Harand et al, 2006;Robledo & Seijo, 2010;Rosato et al, 2017Rosato et al, , 2018Silvestri et al, 2020). Currently, chromosome staining with the fluorochromes chromomycin A 3 (CMA) and 4',6-diamidino-2phenylindole (DAPI) is the most used method to differentiate GC-rich and AT-rich heterochromatic bands, respectively (Guerra, 2000).…”