Late Cenozoic diversification of the austral genus Lagenophora Cass. (Astereae, Asteraceae)

SANCHO,G.; DE LANGE, PETER J.; DONATO, MARIANO; BARKLA, JOHN; WAGSTAFF, STEVE J.

Botanical Journal of the Linnean Society

Wiley

Lugar: London; Año: 2015 vol. 177 p. 78 - 95

1095-8339

P { margin-bottom: 0.21cm; direction: ltr; color: rgb(0, 0, 0); line-height: 200%; widows: 2; orphans: 2; }P.western { font-family: "Calibri",serif; }P.cjk { font-family: "Times New Roman"; }P.ctl { font-family: "Times New Roman"; }A:link { color: rgb(0, 0, 255); } The genus Lagenophora (Astereae, Asteraceae) has 14 species in New Zealand, Australia, Asia, southern South America, and Gough and Tristan da Cunha islands. Phylogenetic relationships within Lagenophora were inferred using nuclear and plastid DNA regions. Reconstruction of spatio-temporal evolution was estimated using parsimony, Bayesian inference and likelihood methods, a Bayesian relaxed molecular clock, and ancestral area and habitat reconstructions. Our results support a narrow taxonomic concept of Lagenophora including only a core group of species with one clade diversifying in New Zealand and another in South America. The split between the New Zealand and South American Lagenophora dates from 11.2 Ma (6.1-17.4 95% HPD). The inferred ancestral habitats were openings in beech forest and subalpine tussockland. The biogeographic analyses inferred a complex ancestral area for Lagenophora involving New Zealand and southern South America. Thus, the estimated divergence times and biogeographic reconstructions provide circumstantial evidence that Antarctica may have served as a corridor for migration until the expansion of the continental ice during the late Cenozoic. The extant distribution of Lagenophora reflects a complex history that could also involve direct long-distance dispersal across southern oceans.