A phylogenetic study of Echidnopsis Hook. f. (Apocynaceae-Asclepiadoideae) - taxonomic implications and the colonization of the Socotran archipelago

We investigated the phylogeny, taxonomy and biogeography of the Eritreo-Arabian genus Echidnopsis Hook. f. (Apocynaceae-Asclepiadoideae). Phylogenetic reconstructions based on nrITS sequence data were obtained using maximum likelihood and parsimony analyses. The results reveal two weakly supported clades, each with a mix of African and Arabian taxa, including the genus Rhytidocaulon, and with four Socotran species forming a subclade of their own. Rather than a vicariance origin of these island elements, our data suggest a single dispersal event from eastern Africa. Echidnopsis thus parallels biogeographic patterns found for other Socotran endemic plants. Our revised taxonomy recognizes 28 species and 4 subspecies in the genus. Two new combinations, E. planiflora subsp. chrysantha and E. sharpei subsp. bavazzani are propose

The genus Metastelma (Asclepiadoideae-Asclepiadeae-Metastelmatinae) in South America

Molecular and morphological analyses are used to circumscribe the genus Metastelma in South America. In northem South America, fourteen species are identified, nine o f them new; and two species are found in Southern South America, one o f them new. The northem South American lineage is retrieved as sister to a clade comprising the type species of Metastelma, M. parviflorum, one o f several Caribbean lineages. The Southern South American lineage remains unresolved. The Central American lineage remains poorly supported monophyletic, but ineludes a species from Jamaica, M. priorii. Several specimens from the Andes o f Argentina and Bolivia are retrieved in a well-supported clade outside Metastelma s.s. For these specimens, a new genus is described comprising presently seven species. Four o f these species are transferred from Metastelma, one from Ditassa, and two species are described as new Stelmation E.Foum. is resurrected, comprising presently a single species, S. myrtifolium from Brazil. Metastelma giuliettianum and M. harleyi, also from Brazil, are excluded from Metastelma, but cannot yet be transferred to another genus, because the taxonomy o f Metastelmatinae is still in flux. Thus, Metastelma s.s. is absent from Brazil

Building a model: developing genomic resources for common milkweed (Asclepias syriaca) with low coverage genome sequencing

<p>Abstract</p> <p>Background</p> <p>Milkweeds (<it>Asclepias </it>L.) have been extensively investigated in diverse areas of evolutionary biology and ecology; however, there are few genetic resources available to facilitate and compliment these studies. This study explored how low coverage genome sequencing of the common milkweed (<it>Asclepias syriaca </it>L.) could be useful in characterizing the genome of a plant without prior genomic information and for development of genomic resources as a step toward further developing <it>A. syriaca </it>as a model in ecology and evolution.</p> <p>Results</p> <p>A 0.5× genome of <it>A. syriaca </it>was produced using Illumina sequencing. A virtually complete chloroplast genome of 158,598 bp was assembled, revealing few repeats and loss of three genes: <it>accD, clpP</it>, and <it>ycf1</it>. A nearly complete rDNA cistron (18S-5.8S-26S; 7,541 bp) and 5S rDNA (120 bp) sequence were obtained. Assessment of polymorphism revealed that the rDNA cistron and 5S rDNA had 0.3% and 26.7% polymorphic sites, respectively. A partial mitochondrial genome sequence (130,764 bp), with identical gene content to tobacco, was also assembled. An initial characterization of repeat content indicated that Ty1/<it>copia</it>-like retroelements are the most common repeat type in the milkweed genome. At least one <it>A. syriaca </it>microread hit 88% of <it>Catharanthus roseus </it>(Apocynaceae) unigenes (median coverage of 0.29×) and 66% of single copy orthologs (COSII) in asterids (median coverage of 0.14×). From this partial characterization of the <it>A. syriaca </it>genome, markers for population genetics (microsatellites) and phylogenetics (low-copy nuclear genes) studies were developed.</p> <p>Conclusions</p> <p>The results highlight the promise of next generation sequencing for development of genomic resources for any organism. Low coverage genome sequencing allows characterization of the high copy fraction of the genome and exploration of the low copy fraction of the genome, which facilitate the development of molecular tools for further study of a target species and its relatives. This study represents a first step in the development of a community resource for further study of plant-insect co-evolution, anti-herbivore defense, floral developmental genetics, reproductive biology, chemical evolution, population genetics, and comparative genomics using milkweeds, and <it>A. syriaca </it>in particular, as ecological and evolutionary models.</p

Taxonomic changes in American Metastelminae (Apocynaceae--Asclepiadoideae)

Volume: 11Start Page: 171End Page: 18

Cynanchum crassipedicellatum (Asclepiadaceae), a new and unusual succulent from Madagascar

Volume: 4Start Page: 276End Page: 27

Ceropegia laotica (Apocynaceae, Asclepiadoideae): the first new species of Ceropegia described from Laos

Volume: 69Start Page: 285End Page: 29

A phylogenetic study of Echidnopsis Hook. f. (Apocynaceae-Asclepiadoideae) - taxonomic implications and the colonization of the Socotran archipelago

We investigated the phylogeny, taxonomy and biogeography of the Eritreo-Arabian genus Echidnopsis Hook. f. (Apocynaceae-Asclepiadoideae). Phylogenetic reconstructions based on nrITS sequence data were obtained using maximum likelihood and parsimony analyses. The results reveal two weakly supported clades, each with a mix of African and Arabian taxa, including the genus Rhytidocaulon, and with four Socotran species forming a subclade of their own. Rather than a vicariance origin of these island elements, our data suggest a single dispersal event from eastern Africa. Echidnopsis thus parallels biogeographic patterns found for other Socotran endemic plants. Our revised taxonomy recognizes 28 species and 4 subspecies in the genus. Two new combinations, E. planiflora subsp. chrysantha and E. sharpei subsp. bavazzani are propose

Two new species and one new combination in leafless Malagasy Cynanchum (Asclepiadaceae)

Volume: 6Start Page: 59End Page: 6

<I>Pelargonium quarciticola</I> (Geraniaceae), a new species from the Knersvlakte.

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