Ecophylogeography of the disjunct South American xerophytic tree species Prosopis chilensis (Fabaceae)

AGUILAR, DANA LUCÍA; ACOSTA, MARÍA CRISTINA; BARANZELLI, MATÍAS CRISTIAN; SÉRSIC, ALICIA NOEMÍ; DELATORRE-HERRERA, JOSE; VERGA, ANIBAL; COSACOV, ANDREA

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020 p. 1 - 17

0024-4066

The intraspecific evolutionary history of South American xerophytic plant species has been poorly explored. Thetree species Prosopis chilensis has a disjunct distribution in four South American regions: southern Peru, southernBolivia, central?western Argentina and central Chile. Here, we combined phylogeographical (based on chloroplastand nuclear markers), morphological and climatic data to evaluate the relative contribution of historical demostochastic and adaptive processes in differentiating the disjunct areas of distribution. The results obtained with thetwo molecular markers revealed two closely related phylogroups (Northern and Southern, predominating in BolivianChaco and in Argentine Chaco/Monte, respectively), which would have diverged at ~5 Mya, probably associatedwith transgression of the Paranaense Sea. Bolivia and Argentina have a larger number of exclusive haplotypes/alleles and higher molecular diversity than Chile, suggesting a long-lasting in situ persistence in the former anda relatively recent colonization in the latter, from the Bolivian and Argentinian lineages. The two main lineagesdiffer in morphology and climatic niche, revealing two significant, independent evolutionary units within P. chilensispromoted by local adaptation and geographical isolation.