Citotaxonomia de três espécies de Cuphea P. Browne

Abstract

The chromosomal number and its morphology are parameters commonly used in cytotaxonomy. The comparative analysis of these characters in related species aids in species distinction, in the study of phylogenetic relations and evolutionary mechanisms between the genera and with other families. These studies are still scarce in many regions and for many species. The chromosomal count of unknown species is very important, as is the recounting of species from distinct populations, due to the possible occurrence of interpopulation variation and the improper registration in literature. The Lythraceae family constituted one of the nine families of the Myrtales order, and the Cuphea P. Browne genus, with near to 260 species, is considered the richest in species of the family. It is also diversified regarding the chromosomal number, with the most common number in Brazil being n = 8, being considered as base chromosomal number for the genus. Despite many chromosomal counts for Cuphea having been done, they are still considered few, requiring more reports to elucidate its phylogenetic and evolutionary relations. Thus, this work aimed at expanding the knowledge of the chromosomal numbers ofCuphea (Lythraceae) in Brazil, as well as use them as taxonomic tools. The studied species presented different chromosomal numbers: C. carthagenensis presents 2n = 24, C. sperguloides presents 2n = 18 and C. thymoides presents 2n = 36, aiding for differentiating the species.