Patterns of distribution and diversification in the M adagascar-centred tribe Danaideae (Rubiaceae)

Abstract

The tribe Danaideae is centred in the Western Indian Ocean Región (including Madagascar and the neighbouring Comoras, Mascarenes, and Seychelles archipelagos). This group o f plants encompasses three genera, the Malagasy endemic Payera (with 15 species) and Schismatoclada (with 47 species), and the mostly Western Indian Ocean genus Danais (with 42 species). The members of the tribe are restricted to three bioclimate zones in Madagascar: humid zone harbouring littoral forests and lowland rainforests along the east; subhumid zone covering highland rainforests along the central highlands; and montane zone mostly in the central highlands above the subhumid zone and characterized by ericoid thickets. We reconstructed a robust phylogeny of Danaideae to investígate the geographic and diversification patterns in Payera and Schismatoclada, using the Bayesian method and combined plastid (matK, ndhF, and trnT-F) and nuclear (nrITS) data. We sampled ca 75% o f species richness o f Payera and Schismatoclada, covering the entire geographic ranges o f Danaideae. The results of this study will be presented and discussed.