A population genetic-level approach to endemic species of Oxalis section Palmatifoliae (Oxalidaceae) in Patagonia

Abstract

Oxalis section Palmatifoliae (wood sorrel) includes five species that are well differentiated morphologically. A previous population study in one of the species (O. laciniata) suggested a complex phylogeographic history and highlighted the need to explore the genetic variability of all the species in the section. Thus, we performed a population level study of the five species to (1) determine the population structure within and among species, (2) model their current and paleoclimatic distributions, and (3) assess the historical processes that influenced their current genetic and morphological variation. We generated inter-simple sequence repeat (ISSR) polymorphism data and DNA sequences for the plastid region trnH-psbA and used those data to obtain a haplotype network, and used georeferenced coordinates and Maxent to obtain present and past species distribution models. Our major results included: 1) ISSR data showed a significant level of genetic differentiation among the five species and a degree of admixture within species; 2) plastid region trnH-psbA shows that one haplotype is the most frequent and widespread among all the species; 3) modelling of species present distributions showed different climatic variables for each species, whereas modelling of past distribution scenarios suggests broader distributions of all species.