Population genetic structure and species delimitation in the Cryptanthus zonatus complex (Bromeliaceae)

Abstract

Abstract Morphological variations of individuals and populations of plants have hampered taxonomists from understanding whether such variations are intra- or interspecific. In this research, we study Cryptanthus burle-marxii and C. zonatus, the morphological variations of which overlap, making it difficult to identify them. Both taxa are restricted to the north of the Brazilian Atlantic Forest and are included in the C. zonatus species complex. We applied different methods such as morphological comparison, population genetics using ten nuclear microsatellite markers and ecological niche modelling to study population genetic structure and species delimitation of this species complex. Our analysis revealed that the two genetic clusters were formed possibly because of the presence of a historical geographical barrier in a region called ‘depressão do Abiaí’. The two genetic clusters were concordant with the northern and southern distribution of the complex but incongruent with a morphological variation or current taxonomic delimitation. Thus, we synonymize C. burle-marxii with C. zonatus and re-evaluate its conservation status as endangered.