Amazonian lowland, white sand areas as ancestral regions for South American biodiversity: Biogeographic and phylogenetic patterns in Potalia (Angiospermae: Gentianaceae) |
| |
Authors: | Cynthia L Frasier Victor A Albert Lena Struwe |
| |
Institution: | aDepartment of Plant Biology and Pathology, Rutgers University, 237 Foran Hall, 59 Dudley Road, New Brunswick, NJ 08901, USA;bNatural History Museum, University of Oslo, 0318 Oslo, Norway;cDepartment of Ecology, Evolution, and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, USA |
| |
Abstract: | Present-day white sand areas in South America are thought to be relictual areas of earlier, widespread habitats now covered by more recent sediments mainly from the Andean orogeny. These ancient, nutrient-poor areas have been suggested to be possible ancestral regions for neotropical plant diversity. Members of the genus Potalia of the Gentianaceae grow in the New World tropics from Costa Rica in the north to southern Bolivia. Until recently, only one Potalia species was accepted, but a new revision identifies eight others. Three species are endemic to lowland, white sand areas in the Amazon and Orinoco basins and share morphological characteristics with Anthocleista, the African – Malagasy sister group to Potalia. To resolve phylogenetic and biogeographic patterns in Potalia, morphological characters and sequences of the internal transcribed spacer (ITS) and the 5S non-transcribed spacer (5S-NTS) of the ribosomal nuclear DNA were collected and used for phylogenetic reconstruction using Bayesian and parsimony-based methods. Potalia species restricted to ancient, nutrient-poor white sand areas of the Amazon Basin and Guayana Shield were placed basal to other Potalia taxa from finer, lateritic, and younger soils, further suggesting that lowland white sand areas may be ancestral seats of neotropical diversity. |
| |
Keywords: | Biogeography Ecological speciation Geology Neotropics Phylogeny Potalieae |
本文献已被 ScienceDirect 等数据库收录! |
|