Dissochaeta Blume (Melastomataceae, tribe Dissochaeteae) is well-known as a scrambling plant genus found in Southeast Asia, where it is an inhabitant of the tropical rainforests or evergreen... Show moreDissochaeta Blume (Melastomataceae, tribe Dissochaeteae) is well-known as a scrambling plant genus found in Southeast Asia, where it is an inhabitant of the tropical rainforests or evergreen forests.The main objectives of this thesis are to clarify the relationships among species and genera within the Dissochaeta alliance and to provide a new classification, which reflects the evolutionary and biogeographic traits of this plant group. The study focuses on three aspects of the Dissochaetaalliance: the taxonomy, molecular phylogeny and historical biogeography. Show less
Kartonegoro, A.; Mota De Oliveira, S.; Welzen, P.C. van 2021
The region of Tropical Southeast Asia and the Malay Archipelago is a very appealing area for research due to its outstanding biodiversity, being one of the most species-rich areas in the world with... Show moreThe region of Tropical Southeast Asia and the Malay Archipelago is a very appealing area for research due to its outstanding biodiversity, being one of the most species-rich areas in the world with high levels of endemism, and due to its complex geological history. The high number of species in tribe Dissochaeteae (Melastomataceae) and their tendency to narrow endemism make the tribe an ideal group for examining biogeographic patterns. We sampled 58 accessions spread over 42 accepted and two undescribed species of the Dissochaeteae. Two nuclear (ETS, ITS) and four chloroplast regions (ndhF, psbK-psbL, rbcL, rpl16) were used for divergence time estimation and ancestral area reconstruction. Results from the molecular dating analysis suggest that the diversity of Dissochaeteae in the Southeast Asian region resulted from a South American ancestor in the late Eocene. The ancestor of the Dissochaeteae might have migrated from South America to Southeast Asia via North America and then entered Eurasia over the North Atlantic land bridge during the Eocene. The origin and early diversification of the Dissochaeteae in Southeast Asia dates back to the middle Oligocene, and most of the genera originated during the Miocene. Indochina and Borneo are most likely the area of origin for the most recent common ancestor of the Dissochaeteae and for many of the early diverging clades of some genera within Southeast Asia. Show less
