TRACING THE CENTRE(S) OF RADIATION IN HIGH ANDEAN GENUS Oritrophium

KOLAR, FILIP; SALOMÓN, LUCIANA; SKLENÁR, PETR

Quito

Congreso; Congreso Latinoamericano de Botánica; 2018

Oritrophium (Kunth) Cuatrecasas (Astereae, Asteraceae), is an exclusively American genus comprising around 30 taxa,mostly distributed in subalpine zone of South America but with two species appearing in Mexico. In its traditional circumscription,the genus has an intriguing distribution of diversity, with species aggregated into southern Ecuadorian andVenezuelan Andes. We reconstructed phylogeny of this group by sequencing two plastid regions and nuclear ITS region,for more than 80 % of the species of the genus. This first phylogeny of Oritrophium shows that the genus is polyphyletic,with only one important radiation centre in the southern Ecuadorian páramos. All four Venezuelan endemic traditionallyassigned to Oritrophium instead, appear more related to Erigeron. On the other hand, our results also support thecorrect assignation of Mexican species to the genus, suggesting a possible scenario of long-distance dispersion northwardsfrom the páramos. Additionally, for the two widely distributed species (Oritrophium limnophillum and O. peruvianum)phylogeographic analyzes suggest a pattern similar to the entire genus, i.e., northward spread of each species from thediversity centre in Ecuador.