Abstract Detail

Systematics

Salomon, Luciana [1], Nicola, Marcela [2], Kandziora, Martha [3], Kolar, Filip [4], Sklenar, Petr [5].

Center of origin and evolutionary history in high Andean genus Oritrophium (Astereae, Asteraceae) from Cordilleras of the Americas.

Páramo, the most species-rich tropical mountain ecosystem, is relatively well-researched in terms of the diversity and evolutionary sources of its flora, yet we know few about diversification within this environment. This study aims to unravel the evolutionary history of Oritrophium, an endemic genus of alpine habitats in Latin America, with a disjunct and bi-modal distribution of its species diversity. We aim to disentangle the center(s) of origin and radiation of the genus, and mechanisms structuring its genetic diversity at inter- and intra-specific level. We sampled 19 species (85% from the total) and extended the sampling at population level for the two widely distributed species, O. limnophilum and O. peruvianum, comprising 19 and 24 populations, respectively. Using nuclear ribosomal internal transcribed spacer (ITS) and trnL-trnF chloroplast DNA region, we reconstructed dated phylogenies to revise monophyly of the genus and unravel possible historical forces underlying its diversification. At the population level, we also constructed haplotype networks and run spatial analyses of molecular variance to explore whether similar mechanism operate on structuring the diversity at intraspecific level. Oritrophium resulted polyphyletic, with two species being closely related to Erigeron and three other species ambiguously related to Erigeron, Diplostephium, and/or Hinterhubera. The remaining 14 species formed a clade, Oritrophium s.s., that likely originated in the Andes of northern Peru-southern Ecuador, which form the center of the genus' diversity, during the Early Pliocene. The group likely diversified with the emergence of the Páramo during the Late Pliocene and further dispersed mainly from South-to-North in the Pleistocene. This migration involved both, long-distance dispersal from the Andes of Peru/Ecuador to Mexico and gradual migration of the species along the Andes. Thus, Oritrophium s.s. would be the first record of plant long-distance dispersal from the Páramo of South America to North America. The dispersal pattern within South America was mirrored by the intraspecific population structure of the investigated species, suggesting similar processes affecting diversification in different time periods.

1 - Charles University, Botany, Benátská 2, Prague, 128 01 , Czech Republic
2 - Instituto de Botánica Darwinion, Labardén 200, San Isidro, Buenos Aires, B1642HYD, Argentina
3 - Department Of Botany, Faculty Of Science - Charles University, Benatska 2, Prague, PR, 12800, Czech Republic
4 - Charles University, Benátská 2, Prague, 128 01, Czech Republic
5 - Charles University, Department Of Botany, BENATSKA 2, PRAHA, PR, 12801, Czech Republic

Keywords:
Andes
Compositae
long-distance dispersal
Páramo
radiation.

Presentation Type: Oral Paper
Session: SYSTI, Systematics I: Euasterids II
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 10:30 AM(EDT)
Number: SYSTI003
Abstract ID:1059
Candidate for Awards:None