| Grant number: | 17/11939-7 |
| Support type: | Regular Research Grants - Publications - Scientific article |
| Duration: | August 01, 2017 - January 31, 2018 |
| Field of knowledge: | Biological Sciences - Genetics - Plant Genetics |
| Principal Investigator: | Fernando de Faria Franco |
| Grantee: | Fernando de Faria Franco |
| Home Institution: | Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil |
| Associated research grant: | 14/25227-0 - Multilocus phylogenetic analysis to recover evolutionary relationships among species of genus Cereus (Cactaceae; Cereeae), AP.R |
Abstract
Aim: to investigate biogeographic influences on xeric biota in the Brazilian Atlantic Forest (BAF), a biodiversity hotspot. To this end, a monophyletic group including three cactus taxa was used as a model to perform a phylogeographic study: Cereus fernambucensis subsp. fernambucensis, C. fernambucensis subsp. sericifer and C. insularis. Location: xeric habitats along BAF, including isolated granite and gneiss rock outcrops (Inselbergs), sand dune vegetation (Restinga forest) and the rocky shore of an oceanic archipelago (islands of Fernando de Noronha). Methods Nucleotide information from nuclear gene phytochrome C (PHYC) and plastid intergenic spacer trnS-trnG were used to perform different statistical analyses. We also used this information to reconstruct the phylogeographic history of our ingroup in both spatial and temporal scales. Results: the structure analysis recovered four allopatric population groups with highly supported branches in a species tree with divergence initiated in the middle Pleistocene: southern distribution of C. fernambucensis subsp. fernambucensis, northern distribution of C. fernambucensis subsp. fernambucensis together with C. insularis, southern distribution of C. fernambucensis subsp. sericifer and northern distribution of C. fernambucensis subsp. sericifer. The independent biogeographic analyses suggested southern distribution as a likely ancestral area. Main conclusions: the results have shown that genetic diversity of population groups was strongly shaped by an initial colonization event from south to north followed by fragmentation. The phylogenetic pattern found for C. insularis is plausible with peripatric speciation in the archipelago of Fernando de Noronha. To explain the phylogeographic patterns, the putative effects of both climatic and sea level changes as well as neotectonic activity during the Pleistocene are discussed. (AU)