Systematics and Biogeography of the Clusioid Clade (Malpighiales)

The clusioids are a clade of flowering plants in the diverse rosid order Malpighiales. It includes five families (i.e., Bonnetiaceae, Calophyllaceae, Clusiaceae sensu stricto, Hypericaceae, and Podostemaceae) that form a conspicuous element of tropical forests worldwide and are economically important. Their phylogenetic and biogeographical history has remained uncertain, however, which has hindered our understanding of their evolution. I conducted the first taxon-rich multigene analysis of this important clade to clarify their phylogenetic relationships (Chapter 1). Plastid (cp:matK, ndhF, and rbcL) and mitochondrial (mt: matR) nucleotide sequence data from nearly 200 taxa produced a well-resolved clusioid phylogeny and indicate that several traditionally recognized genera are not monophyletic. These results provide a strong framework for improving the classification of the group. To further determine the placement of several key taxa lacking molecular data, especially the ancient fossil rosid Paleoclusia (-90 Myr), I assembled a morphological data set that I analyzed in combination with the cp and mt data (Chapter 2). My results support previous hypotheses of phylogenetic relationships for extant taxa and indicate that Paleoclusia is weakly placed as a member of the clusioid subclade Clusiaceae sensu stricto. Finally, I inferred molecular divergence estimates and ancestral ranges for the clade to test the hypothesis iii that the pantropical distribution of many clusioid subclades is attributable to ancient Gondwanan vicariance (Chapter 3). The clusioids are ideal for examining this topic due to their well-sampled and strongly supported phylogeny, pantropical distribution, and ancient fossil record. Our results suggest a single Gondwanan vicariant event early in the history of the clade, followed by prevalent dispersal throughout the Cenozoic, most of which occurred after the mid-Eocene. These results are consistent with a growing body of literature that suggests that many traditionally recognized angiosperm clades are far too young for their distributions to have been influenced strictly by Gondwanan vicariance. Instead, it appears that dispersal is a more likely explanation for many Gondwanan distributions in angiosperms including the clusioids

From Algae to Angiosperms – Inferring the Phylogeny of Green Plants ( Viridiplantae ) from 360 Plastid Genomes

Background Next-generation sequencing has provided a wealth of plastid genome sequence data from an increasingly diverse set of green plants (Viridiplantae). Although these data have helped resolve the phylogeny of numerous clades (e.g., green algae, angiosperms, and gymnosperms), their utility for inferring relationships across all green plants is uncertain. Viridiplantae originated 700-1500 million years ago and may comprise as many as 500,000 species. This clade represents a major source of photosynthetic carbon and contains an immense diversity of life forms, including some of the smallest and largest eukaryotes. Here we explore the limits and challenges of inferring a comprehensive green plant phylogeny from available complete or nearly complete plastid genome sequence data. Results We assembled protein-coding sequence data for 78 genes from 360 diverse green plant taxa with complete or nearly complete plastid genome sequences available from GenBank. Phylogenetic analyses of the plastid data recovered well-supported backbone relationships and strong support for relationships that were not observed in previous analyses of major subclades within Viridiplantae. However, there also is evidence of systematic error in some analyses. In several instances we obtained strongly supported but conflicting topologies from analyses of nucleotides versus amino acid characters, and the considerable variation in GC content among lineages and within single genomes affected the phylogenetic placement of several taxa. Conclusions Analyses of the plastid sequence data recovered a strongly supported framework of relationships for green plants. This framework includes: i) the placement of Zygnematophyceace as sister to land plants (Embryophyta), ii) a clade of extant gymnosperms (Acrogymnospermae) with cycads + Ginkgo sister to remaining extant gymnosperms and with gnetophytes (Gnetophyta) sister to non-Pinaceae conifers (Gnecup trees), and iii) within the monilophyte clade (Monilophyta), Equisetales + Psilotales are sister to Marattiales + leptosporangiate ferns. Our analyses also highlight the challenges of using plastid genome sequences in deep-level phylogenomic analyses, and we provide suggestions for future analyses that will likely incorporate plastid genome sequence data for thousands of species. We particularly emphasize the importance of exploring the effects of different partitioning and character coding strategies. http://www.biomedcentral.com/1471-2148/14/2

Collections Education: The Extended Specimen and Data Acumen

Biodiversity scientists must be fluent across disciplines; they must possess the quantitative, computational, and data skills necessary for working with large, complex data sets, and they must have foundational skills and content knowledge from ecology, evolution, taxonomy, and systematics. To effectively train the emerging workforce, we must teach science as we conduct science and embrace emerging concepts of data acumen alongside the knowledge, tools, and techniques foundational to organismal biology. We present an open education resource that updates the traditional plant collection exercise to incorporate best practices in twenty-first century collecting and to contextualize the activities that build data acumen. Students exposed to this resource gained skills and content knowledge in plant taxonomy and systematics, as well as a nuanced understanding of collections-based data resources. We discuss the importance of the extended specimen in fostering scientific discovery and reinforcing foundational concepts in biodiversity science, taxonomy, and systematics

From algae to angiosperms–inferring the phylogeny of green plants (Viridiplantae) from 360 plastid genomes

Background Next-generation sequencing has provided a wealth of plastid genome sequence data from an increasingly diverse set of green plants (Viridiplantae). Although these data have helped resolve the phylogeny of numerous clades (e.g., green algae, angiosperms, and gymnosperms), their utility for inferring relationships across all green plants is uncertain. Viridiplantae originated 700-1500 million years ago and may comprise as many as 500,000 species. This clade represents a major source of photosynthetic carbon and contains an immense diversity of life forms, including some of the smallest and largest eukaryotes. Here we explore the limits and challenges of inferring a comprehensive green plant phylogeny from available complete or nearly complete plastid genome sequence data. Results We assembled protein-coding sequence data for 78 genes from 360 diverse green plant taxa with complete or nearly complete plastid genome sequences available from GenBank. Phylogenetic analyses of the plastid data recovered well-supported backbone relationships and strong support for relationships that were not observed in previous analyses of major subclades within Viridiplantae. However, there also is evidence of systematic error in some analyses. In several instances we obtained strongly supported but conflicting topologies from analyses of nucleotides versus amino acid characters, and the considerable variation in GC content among lineages and within single genomes affected the phylogenetic placement of several taxa. Conclusions Analyses of the plastid sequence data recovered a strongly supported framework of relationships for green plants. This framework includes: i) the placement of Zygnematophyceace as sister to land plants (Embryophyta), ii) a clade of extant gymnosperms (Acrogymnospermae) with cycads + Ginkgo sister to remaining extant gymnosperms and with gnetophytes (Gnetophyta) sister to non-Pinaceae conifers (Gnecup trees), and iii) within the monilophyte clade (Monilophyta), Equisetales + Psilotales are sister to Marattiales + leptosporangiate ferns. Our analyses also highlight the challenges of using plastid genome sequences in deep-level phylogenomic analyses, and we provide suggestions for future analyses that will likely incorporate plastid genome sequence data for thousands of species. We particularly emphasize the importance of exploring the effects of different partitioning and character coding strategies. http://www.biomedcentral.com/1471-2148/14/2

Phylogeny of the Clusioid Clade (Malpighiales): Evidence from the Plastid and Mitochonrial Genomes

• Premise of the study : The clusioid clade includes five families (i.e., Bonnetiaceae, Calophyllaceae, Clusiaceae s.s., Hypericaceae, and Podostemaceae) represented by 94 genera and ~1900 species. Species in this clade form a conspicuous element of tropical forests worldwide and are important in horticulture, timber production, and pharmacology. We conducted a taxon-rich multigene phylogenetic analysis of the clusioids to clarify phylogenetic relationships in this clade. • Methods : We analyzed plastid ( matK , ndhF , and rbcL ) and mitochondrial ( matR ) nucleotide sequence data using parsimony, maximum likelihood, and Bayesian inference. Our combined data set included 194 species representing all major clusioid subclades, plus numerous species spanning the taxonomic, morphological, and biogeographic breadth of the clusioid clade. • Key results : Our results indicate that Tovomita (Clusiaceae s.s.), Harungana and Hypericum (Hypericaceae), and Ledermanniella s.s. and Zeylanidium (Podostemaceae) are not monophyletic. In addition, we place four genera that have not been included in any previous molecular study: Ceratolacis , Diamantina , and Griffi thella (Podostemaceae), and Santomasia (Hypericaceae). Finally, our results indicate that Lianthus , Santomasia , Thornea , and Triadenum can be safely merged into Hypericum (Hypericaceae). • Conclusions : We present the first well-resolved, taxon-rich phylogeny of the clusioid clade. Taxon sampling and resolution within the clade are greatly improved compared to previous studies and provide a strong basis for improving the classification of the group. In addition, our phylogeny will form the foundation for our future work investigating the biogeography of tropical angiosperms that exhibit Gondwanan distributions. DOI:10.3732/ajb.100035

Favorable Climate Change Response Explains Non-Native Species' Success in Thoreau's Woods

Invasive species have tremendous detrimental ecological and economic impacts. Climate change may exacerbate species invasions across communities if non-native species are better able to respond to climate changes than native species. Recent evidence indicates that species that respond to climate change by adjusting their phenology (i.e., the timing of seasonal activities, such as flowering) have historically increased in abundance. The extent to which non-native species success is similarly linked to a favorable climate change response, however, remains untested. We analyzed a dataset initiated by the conservationist Henry David Thoreau that documents the long-term phenological response of native and non-native plant species over the last 150 years from Concord, Massachusetts (USA). Our results demonstrate that non-native species, and invasive species in particular, have been far better able to respond to recent climate change by adjusting their flowering time. This demonstrates that climate change has likely played, and may continue to play, an important role in facilitating non-native species naturalization and invasion at the community level

Another look at the root of the angiosperms reveals a familiar tale

Since the advent of molecular phylogenetics more than 25 years ago, a major goal of plant systematists has been to discern the root of the angiosperms. While most studies indicate that Amborella trichopoda is sister to all remaining extant flowering plants, support for this position has varied with respect to both the sequence data sets and analyses employed. Recently, Goremykin et al. (2013) questioned the “Amborella-sister hypothesis” using a “noise-reduction” approach and reported a topology with Amborella + Nymphaeales (water lilies) sister to all remaining angiosperms. Through a series of analyses of both plastid genomes and mitochondrial genes, we continue to find mostly strong support for the Amborella-sister hypothesis and offer a rebuttal of Goremykin et al. (2013). The major tenet of Goremykin et al. is that the Amborella-sister position is determined by noisy data – i.e. characters with high rates of change and lacking true phylogenetic signal. To investigate the signal in these noisy data further, we analyzed the discarded characters from their noise-reduced alignments. We recovered a tree identical to that of the currently accepted angiosperm framework, including the position of Amborella as sister to all other angiosperms, as well as all other major clades. Thus, the signal in the “noisy” data is consistent with that of our complete data sets – arguing against the use of their noise-reduction approach. We also determined that one of the alignments presented by Goremykin et al. yields results at odds with their central claim – their data set actually supports Amborella as sister to all other angiosperms, as do larger plastid data sets we present here that possess more complete taxon sampling both within the monocots and for angiosperms in general. Previous unpartitioned, multi-locus analyses of mtDNA data have provided the strongest support for Amborella + Nymphaeales as sister to other angiosperms. However, our analysis of third codon positions from mtDNA sequence data also supports the Amborella-sister hypothesis. Finally, we challenge the conclusion of Goremykin et al. that the first flowering plants were aquatic and herbaceous, reasserting that even if Amborella + water lilies, or water lilies alone, are sister to the rest of the angiosperms, the earliest angiosperms were not necessarily aquatic and/or herbaceous

Digitization workflows for flat sheets and packets of plants, algae, and fungi

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141708/1/aps31500065.pd

Data access for the 1,000 Plants (1KP) project

© 2014 Matasci et al.; licensee BioMed Central Ltd. The 1,000 plants (1KP) project is an international multi-disciplinary consortium that has generated transcriptome data from over 1,000 plant species, with exemplars for all of the major lineages across the Viridiplantae (green plants) clade. Here, we describe how to access the data used in a phylogenomics analysis of the first 85 species, and how to visualize our gene and species trees. Users can develop computational pipelines to analyse these data, in conjunction with data of their own that they can upload. Computationally estimated protein-protein interactions and biochemical pathways can be visualized at another site. Finally, we comment on our future plans and how they fit within this scalable system for the dissemination, visualization, and analysis of large multi-species data sets