Phylogeography in the Payunia District: evolutionary history of two endemics Adesmia species with contrasting live forms

AGUILAR, DANA; ROCAMUNDI, NICOLAS; ISSALY, ANDRES; CAMPS, ANDRES; JOHNSON LEIGH; COSACOV ANDREA; SÉRSIC, ALICIA N.; BARANZELLI MATIAS C

Ohio

Congreso; Society for Systematic Biologists Standalone meeting 2018; 2018

Society for Systematic Biologists

To understand the evolutionary history of plant community of the PayuniaDistrict and to assess the impact of Pleistocene glaciations on vegetation thatspan the southern area of the Arid Diagonal, we investigated thephylogeography of two endemic plant species with contrasting life forms:Adesmia pinifolia Gillies ex Hook. & Arn. (Fabaceae; shrub), and Adesmiaquadripinnata (Hicken) Burkart (Fabaceae, herb). We hypothesize that, given the unique climate and topography of this region, the plant community responds together to the Quaternary oscillations. If not, intrinsic species life-history could have modeled functional idiosyncratic responses to the past climatic change (herbaceous vs shrubs) allowing their survival during Quaternary cycles across their entire distribution range.This study is part of a wider research about the effect of past climatic changes on plant community of the Payunia District. We only present the results of two broad distributed endemic plant species that were selected for genetic analysis with contrasting life forms. Herbaceous plants characterized by higher rates of molecular and climatic niche evolution, and faster growth rates compared with woody species (shrub), would have been less affected by glacial?interglacial cycles during Quaternary, facilitating the colonization of new habitats. In that sense, we saw this pattern. The endemic herb from the Payunia District are the first to diversify (with a more ancient MCRA and more mutational changes accumulated between haplotypes) and then the shrub follow. Both diversification may have been favored in the Quaternary when arid and semiarid lands reached their widest extent due to the rain-shadow effect generated after the last phases of the uplift of the Andean Cordillera, about 7-10 Mya . According to the RRW results, the origin of the distribution range of both species it would match with the highest points of suitability observed on the map of ENM for the region that would indicate it as a point of climatic stability. In recent times, we observe that the northern populations are growing than the southern lineages. We conclude that all the results confirm our hypothesis about that the plant community responds together to the Quaternary oscillations in the Payunia District and not respond like its intrinsic life-history to the past climatic change.