Reconstructing geo-spatial and temporal patterns of genetic variability of Anadenanthera colubrina var. cebil: coupling phylogeographical and species distribution modelling analyses

BARRANDEGUY, M.E.; DUSSET, F.; ZERDA, H.; SAVINO, C.; MOGNI, V.Y.; PRADO, D.E.; GARCÍA, M.V.

Foz do Iguaçú

Congreso; XXII International Congress of Genetics; 2018

Asociación Latinoamericana de Genética

The effects of Quaternary climatic fluctuations on the historical dynamics of Seasonally Dry Tropical Forests (SDTFs) was evaluated by means of phylogeographical analysis and species distribution modellingof Anadenanthera colubrina var. cebil, the most paradigmatic tree species of these forests. In this way, two non-coding regions of plastid DNA (intron trnL and intergenic spacer trnF-trnL) were sequenced in 41 individuals from 19 South American locations. Two groups were defined with both Neighbour-joining tree and median-joining network. These analyses showed a Misiones and a Sub-Andean Piedmont groups. Misiones group had higher number of haplotypes than Sub-Andean Piedmont despite shorter geographic distance among individuals from Misiones. The divergence time estimated between haplotypes date in the Upper Pleistocene (93%) and Holocene (7%). Paleodistribution models suggested that species distribution showed an Amazonian expansion in the Last Glacial Maximum (22 kyr BP) and a contraction in the Holocene (6 kyr BP). However, in the present the distribution showed an expansion and colonization southward in concordance with the species current distribution. These patterns could be explained by seasonality climatic variables. The phylogeographical groups showed concordance with the floristic units described for SDTFs. The low genetic diversity in Sub-Andean Piedmont suggests a recent southward expansion of the range of the species after the Holocene, supporting the hypothesis of the southward expansion of SDTFs. The spatial and temporal patterns of divergence in A. colubrina var. cebil could be associated with possible historical changes in the distribution more than with the geographical distances between the current distribution patches of the SDTFs.