Phylogenetic analysis of Phylica L. (Rhamnaceae) with an emphasis on island species: evidence from plastid trnL‐F and nuclear internal transcribed spacer (ribosomal) DNA sequences

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. . International Association for Plant Taxonomy (IAPT) is collaborating with JSTOR to digitize, preserve and extend access to Taxon. Chase, M. W.: Phylogenetic analysis of Phylica L. (Rhamnaceae) with an emphasis on island species: evidence from plastid trnL-F DNA and nuclear internal transcribed spacer (ribosomal DNA) sequences. -Taxon 50: 405-427. 2001. -ISSN 0040-0262.The relationships of the island species of Phylica and other genera in Phyliceae (Rhamnaceae) were evaluated using sequences for the plastid trnL intron, the trnL-F intergenic spacer and the internal transcribed spacers of nuclear ribosomal DNA. Both regions provided nearly identical phylogenetic patterns, so they were analysed as a combined matrix. The genera Nesiota and Noltea were found to be palaeoendemic species within the context of the tribe. The island species of Phylica formed a monophyletic group together with the widespread mainland species, P. paniculata. The plesiomorphic, generalist morphology of this group contrasts with the derived morphological characteristics of the majority of mainland species. However, the group occupies a derived position in the phylogenetic trees, thus indicating either a reversal or more likely the retention of these primitive traits.

Species Delimitation and the Origin of Populations in Island Representatives of Phylica (Rhamnaceae)

“…Only patterns in uniparentally inherited genomes might be expected to still exhibit evidence of paraphyly. In the DNA sequence analysis of plastid trnL-F (Richardson et al 2001a), there was weak evidence for paraphyly of P. paniculata, but this might also be due to differential inheritance of ancestral polymorphisms. Further study is required to better document this scenario.…”

“…No fresh or silica-gel dried material of this species was available, and so it was not included in this study, but a trnL-F sequence derived from DNA extracted from herbarium material indicated that it was part of the island group (Richardson et al 2001a). Efforts to use the DNA extracted from herbarium material to produce an AFLP profile for this species were unsuccessful.…”

“…5). The hypothesized relationships between island species and populations and the estimated sequence and timings of dispersals are presented in Figure 6 (updated and modified from the figure in Richardson et al 2001a). …”

People and wildlife in the Tristan da Cunha islands

“…The species may have dispersed from Gough to Ile Amsterdam as recently as 0.5 million years ago, and birds are the most plausible vector. [9] Rather similarly, mitochondrial DNA sequence data for subunit I of cytochrome oxidase has been used to create a phylogenetic tree for the mollusc genus Balea, including five species endemic to the Tristan-Gough group. It seems clear not only that the Tristan-Gough species arose from a single ancestor, but that ancestor shared an ancestral stock with a cluster of species in the Azores and Madeira, the Azorean ancestor itself being derived from Palaearctic stock.…”

Phylogeny of Pelargonium (Geraniaceae) Based on DNA Sequences from Three Genomes

“…The Cape flora of South Africa has always been of special interest to botanists and, over the past decade, has been the subject of studies focussing on (phylogenetic) patterns and processes underlying the species-level radiations mentioned above (e.g., Johnson, 1996;Johnson & al., 1998;Bakker & al., 1999b;Richardson & al., 2001;Goldblatt & al., 2002). Of special interest is whether these radiations occurred simultaneously, perhaps in a concerted response to a changing environmental or climatic factor.…”