Phylogeography of Schlechtendalia luzulifolia, a member ofthe basal subfamily Barnadesioideae (Asteraceae) ID:

KLUSCH M. C.; SALARIATO D. C.; STUESSY T. F.; NICOLA M.V.; BONIFACINO M. J.; FREIRE, S. E.; DELFINI M. C.; URTUBEY E.

Madrid

Congreso; XX International Botanical Congress; 2024

Schlechtendalia luzulifolia Less. belongs to the basal South American subfamily Barnadesioideae (Asteraceae). It is a perennialherb that diverges morphologically, geographically and ecologically from the other nine barnadesioid genera. This monospecificgenus is mainly distributed across the ecoregions of eastern Argentina, Uruguay and southern Brazil (Rio Grande do Sul andParaná). The objective of this study is to understand the evolutionary history and genetic diversity and structure of this taxon. Wehave conducted phylogeographic studies based on a wide populational sampling, using nuclear and plastid markers for analysinggenetic spatial distribution, diversity and structure, test for range expansion, and reconstruct ancestral areas. In addition, climaticniches of the main phylogeographic groups were studied and compared using multivariate techniques in environmental space. Ourresults reveal two main haplogroups associated with: (1) savannas (Argentina and Uruguay) and grasslands (Uruguay and RioGrande do Sul, Brazil); and (2) grasslands of the northern portion of the Araucaria moist forest (Paraná, Brazil). Likewise,ecological niche comparisons in n-dimensional space showed that populations belonging to these two phylogeographic groups differ not only in the ecoregions where they are distributed, but also in the climatic niches they occupy. These results evidence amajor genetic and ecological differentiation for Schlechtendalia populations into two main phylogroups, which suggest historicalprocesses that may have influenced divergence of these two metapopulations. Furthermore, results emphasize that for thisspecies, which grows in grasslands strongly threatened by human activity, not only should conservation of the species itself beproposed, but also of its main phylogeographic groups.