Species diversification in the lowlands of mid-latitude South America: Turnera sidoides subsp. carnea as a case of study

MORENO, E. M. S.; VIA DO PICO, G. M.; KOVALSKI, I. E. ; ROGGERO LUQUE, J. M.; SEIJO, J. G.; SOLIS NEFFA, V. G.

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Año: 2021 vol. 93

0001-3765

The lowlands of mid-latitude South America comprise complex temperateecoregions characterized by a unique biodiversity. However, the processes responsiblefor shaping its species diversity are still largely unknown. Turnera sidoides subsp.carnea is a variable subspecies occurring in the lowlands of northeastern Argentinaand Uruguay, extending to southern Paraguay and Brazil. It constitutes a good modelto perform evolutionary studies. Here we used an integrative approach to understandthe process of diversifi cation within this subspecies and to increase the knowledgeconcerning patterns and processes responsible for shaping the species diversity inthe temperate lowlands of South America. The results provided strong evidences thatthis subspecies is an autopolyploid complex per se, being in an active process ofintrasubspecifi c diversifi cation. Morphological and genetic data show that the diversityof T. sidoides subsp. carnea is in congruence with the great past and present abiotic andbiotic variability of the mid-latitude South American lowlands. The evolutionary historyof this subspecies is consistent with past fragmentation and allopatric differentiationat diploid level. Geographic isolation and local adaptation would have promoted strongmorphological, ecological, and genetic differentiation, resulting in two morphotypes anddifferent genetic groups indicative of incipient speciation.