Demographic history and genetic diversity of modern and herbarium collections of Arabidopsis thaliana from South America.

ROWAN, B; KASULIN, L; SCHUENEMANN V; BOREVITZ, J; KRAUSE J; WEIGEL D; BOTTO JF

Congreso; Plant Biology 2014; 2014

The model plant, Arabidopsis thaliana, has a native range throughout Eurasia and North Africa and introduced populations have been found on several additional continents. Through the RegMap and 1001 Genomes projects, high resolution genetic data has been obtained for thousands of A. thaliana populations that are mostly distributed throughout the Northern Hemisphere. To gain insight into the genetic variation and demographic history of introduced populations of A. thaliana in the Southern Hemisphere, we collected plants from four ecologically diverse sites (ranging from a few hundred meters to 70 km) at the southernmost end of the species distribution in Patagonia, Argentina and analyzed the genetic diversity by low-resolution SNP genotyping and whole-genome sequencing. We also performed whole-genome sequencing of the DNA from an herbarium specimen collected in this region in 1967. We found that individuals from all four modern populations were essentially genetically uniform across 149 SNP markers. Whole-genome sequencing revealed that only a small fraction of the genome is segregating among these strains. Genetic comparisons with the RegMap panel and 1001 Genomes data suggested a likely European origin for these populations. Genetic analysis of the herbarium strain will provide additional insights into the processes of mutation and selection that have occurred over nearly half a century in Patagonia.