Mountains as refugia in the Dry Chaco: phylogeography and species distribution modeling of the southernmost chili pepper Capsicum chacoense Hunz. (Solanaceae)

SCALDAFERRO M; SÉRSIC AN; ROMANUTTI A; ACOSTA MC

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023

0024-4066

Phylogeographic studies combined with species distribution modeling may provide evidence for past climate refugia. During the Pleistocene, the Chaco phytogeographic province (ChPP) underwent changes in the distribution range and the flora may have found refugia in different habitats according to their climatic requirements. This contribution aims to infer the effects of historical geo-climatic changes on the evolutionary history of C. chacoense, the southernmost chili pepper growing in the (ChPP). We analyzed 27 localities with chloroplast and 23 with nuclear markers, covering the species geographic range. We performed statistical phylogeography, and current and past species distribution modeling (SDM). We found three haploclades diverging 2.3-1 Mya intermingled throughout the mountain ranges of the ChPP as a consequence of glacial cycles. According to the SDM, the expansion of the species distribution occurred during interglacial periods. We found two dispersal routes from south to north of the species distribution, concomitant with the migration routes of birds that disperse their fruits. Spatial distribution of genetic diversity showed highest genetic diversity values at higher altitudes. The main orographic systems of the study area were identified as areas of presumed population stability. Consequently, mountains are priority regions for conservation because they contain areas with high genetic diversity.