Valerianaceae

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

Amanda B. Cemper - One of the best experts on this subject based on the ideXlab platform.

James R. Manhart - One of the best experts on this subject based on the ideXlab platform.

Charles D. Bell - One of the best experts on this subject based on the ideXlab platform.

  • Exploring the utility of "next-generation" sequence data on inferring the phylogeny of the South American Valeriana (Valerianaceae).
    Molecular phylogenetics and evolution, 2018
    Co-Authors: Charles D. Bell, Lauren A Gonzalez
    Abstract:

    Abstract This study aimed to investigate the phylogenetic utility of genotyping-by-sequencing (GBS) data in the southern South American subclade of Valerianaceae (Dipsacales). The variety of forms that has arisen in this clade, presumably over the past 5–10 million years, has all the signatures of an adaptive and rapid radiation. While the phylogeny of Valerianaceae has received a great deal of attention in the last decade, species relationships have been hard to resolve using traditional phylogenetic markers. Here, we collected high-throughput genomic sequence data from reduced-representation libraries obtained through GBS protocols. Putative orthologs were identified using within- and among-sample clustering using the computer software pyRAD. We recovered over 3000 loci for 14 species of southern South American Valeriana, with 140 loci present across all samples. We analyzed a set of phylogenetic trees generated from each locus using maximum likelihood methods, as well as multispecies coalescent (∗BEAST) methods. For comparative purposes, we also used a supermatrix approach to infer the phylogeny for these taxa. Across different methods and data sets, we recovered consistent relationships for the southern South American valerians that we sampled with varying degrees of support.

  • Resolving Relationships within Valerianaceae (Dipsacales): New Insights and Hypotheses from Low-Copy Nuclear Regions
    Systematic Botany, 2015
    Co-Authors: Charles D. Bell, Lauren A Gonzalez, Gloria Calderon, Andrea Scholz, Sigrid Liede-schumann
    Abstract:

    Abstract Primers from a recently published study that identified a set of low-copy nuclear genes (LCNG) in multiple angiosperms were used to obtain sequence data from three LCNG (Chlp, Agt1, and Hmgs) for phylogenetic inference at the species level. The phylogenetic utility of each of these markers was compared to ITS and seven chloroplast loci (trnL, trnG-S, ycf5, accD, rpoC1, trnK intron, psbM-trnD intergenic spacer) widely used in phylogenetic analyses. Here we use Valerianaceae as an example for two reasons: 1) the group has a well-supported “backbone” phylogeny based on numerous molecular markers; and 2) there are several species groups (e.g. the South American taxa) that have been particularly difficult to resolve, potentially due to a rapid or recent radiation. Although these new markers added nucleotide characters, they did not provide significant phylogenetic information to resolve relationships among closely related species of Valerianaceae. Likewise, relationships among some of the major clades...

  • Phylogeny and diversification of Valerianaceae (Dipsacales) in the southern Andes
    Molecular phylogenetics and evolution, 2012
    Co-Authors: Charles D. Bell, Adriana Kutschker, Mary T. K. Arroyo
    Abstract:

    The southern Andean clade of Valeriana provides an excellent model for the study of biogeography. Here we provide new data to help clarify phylogenetic relationships among the South American valerians, with special focus on taxa found in the southern Andes. We found that the southern Andean taxa formed a clade in maximum likelihood and maximum parsimony analyses, and used a Bayesian relaxed clock method to estimate divergence times within Valerianaceae. Our temporal results were similar to other studies, but we found greater variance in our estimates, suggesting that the species of Valeriana have been on the South American continent for some time, and have been successful at exploiting new niche opportunities that reflects the contemporary radiation. Regardless of the time frame for the radiation of the clade, the uptick in the rate of diversification in Valerianaceae appears correlated with a dispersal event from Central to South America. The appearance of Valeriana in the southern Andes (13.7 Ma) corresponds with the transition from closed forest on the western side of the Andes in central Chile to a more open Mediterranean woodland environment. This would suggest that the high species richness of Valerianaceae in South America is the result of multiple, smaller radiations such as the one in the southern Andes, that may or may not be geographically isolated. These smaller radiations may also be driven by species moving into new biomes (migration from a temperate to a more Mediterranean-type climate and into alpine). The degree to which different ecological and geological factors interact to drive diversification is difficult to ascertain. Likewise, without a better-resolved phylogeny it is impossible to determine the directionality of dispersal in this group; did they colonize the southern Andes first, then move northward as the central Andean alpine habitat became more widely available or vice versa?

  • Phylogeny and biogeography of Valerianaceae (Dipsacales) with special reference to the South American valerians
    Organisms Diversity & Evolution, 2005
    Co-Authors: Charles D. Bell, Michael J. Donoghue
    Abstract:

    Species of Valerianaceae are a common component of the alpine flora throughout the Northern Hemisphere as well as the Andes of South America.Sequence data from three chloroplast markers ( psbA-trnH intron, trnK-matK intron, and the trnL-F region) along with the internal transcribed spacer region (ITS) of nuclear ribosomal DNA were used to infer relationships within Valerianaceae.Both genomes, as well as a combined data set, provide support for the major clades within the group and do not support a monophyletic Valeriana.In addition, these data indicate that Plectritis is nested within South American Valeriana, as opposed to being sister to Centhranthus as previously hypothesized. Valerianaceae appear to have originated in Asia, probably in the Himalayas, and subsequently to have dispersed several times to Europe and to the New World.Our results imply that Valerianaceae colonized South America on multiple occasions from the north.In one of these cases there appears to have been a substantial and rapid radiation, primarily in the high elevation paramo habitat.A variety of methods were used to estimate divergence times to determine when Valerianaceae might have colonized South America.Regardless of the method and fossil constraints applied, our estimates suggest that Valerianaceae colonized South America prior to the formation of the Isthmus of Panama.

  • Phylogeny and biogeography of Morinaceae (Dipsacales) based on nuclear and chloroplast DNA sequences
    Organisms Diversity & Evolution, 2004
    Co-Authors: Charles D. Bell, Michael J. Donoghue
    Abstract:

    Abstract The Morinaceae (Dipsacales) contains 13 species placed in Acanthocalyx, Cryptothladia or Morina, and is distributed from the mountains of southeastern Europe through the Himalayas to the Qinghai-Tibetan Plateau, mainly in alpine habitats. Sequence data from two chloroplast regions (the trnK intron and the trnL-F region) and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were used to infer phylogenetic relationships of Morinaceae and related Dipsacales. Both the nuclear and chloroplast datasets, as well as the combined data, provide strong support for relationships within the Valerina clade, placing Morinaceae as the sister group of a clade containing Valerianaceae and Dipsacaceae plus Triplostegia. The Morinaceae, Acanthocalyx, Cryptothladia, and a clade containing Morina and Cryptothladia, are all supported as monophyletic. However, Morina was found to be paraphyletic in several of our analyses, with Morina longifolia more closely related to Cryptothladia than to other Morina species. There is some evidence that Morina longifolia produces cleistogamous flowers, as do Cryptothladia species. Dispersal-vicariance analyses support the view that Valerina radiated initially within Asia, with subsequent movement into Europe in Morinaceae, Dipsacaceae, and Valerianaceae, and into the New World in Valerianaceae. For Morinaceae, as for a number of plant groups, the Brahmaputra river drainage marks a significant biogeographic divide, although this has been spanned within Acanthocalyx and the Morina-Cryptothladia lineage.

Hugh D. Wilson - One of the best experts on this subject based on the ideXlab platform.

F. Weberling - One of the best experts on this subject based on the ideXlab platform.

Related terms

Valerianaceae - 15 days free trial to Access Experts & Abstracts