17 research outputs found
Systematics of Xanthorrhoeaceae Sensu Lato, with an Emphasis on Bulbine
We provide here results of a combined analysis of plastid genes rbcL, matK, and ndhF for Xanthorrhoeaceae s.l., the Asphodelaceae/Xanthorrhoeaceae/Hemerocallidaceae clade, which are well supported by the DNA data. Xanthorrhoea (often treated as the sole member of Xanthorrhoeaceae) is sister to the hemerocallid clade (former Hemerocallidaceae); and the asphodelid clade (formerly Asphodelaceae) is sister to them both. For additional species of Bulbine and Jodrellia (both Asphodeloideae), we also collected rps16 intron and ITS nuclear ribosomal DNA sequences to better assess their relationships. Bulbine, with Jodrellia, embedded are sister to the collective genera of subfamily Alooideae in which all species are characterized by strongly bimodal and nearly identical karyotypes, whereas that of Bulbine is much more variable. Cytological studies have previously shown Bulbine to possess a range of karyotypes from graduated to clearly bimodal (although never exactly like the aloid genera) and point toward a lower level of bimodality in the Australian members, all of which are autotetraploid, than in the African members, all of which are diploid. Therefore, there have been two events of particular interest within Bulbine, a change in ploidy and a long-range dispersal event
Multigene Analyses of Monocot Relationships
We present an analysis of supra-familial relationships of monocots based on a combined matrix of nuclear I8S and partial 26S rDNA, plastid atpB, matK, ndhF, and rbcL, and mitochondrial atp1 DNA sequences. Results are highly congruent with previous analyses and provide higher bootstrap support for nearly all relationships than in previously published analyses. Important changes to the results of previous work are a well-supported position of Petrosaviaceae as sister to all monocots above Acorales and Alismatales and much higher support for the commelinid clade. For the first time, the spine of the monocot tree has some bootstrap support, although support for paraphyly of liliids is still only low to moderate (79-82%). Dioscoreales and Pandanales are sister taxa (moderately supported, 87- 92%), and Asparagales are weakly supported (79%) as sister to the commelinids. Analysis of just the four plastid genes reveals that addition of data from the other two genomes contributes to generally better support for most clades, particularly along the spine. A new collection reveals that previous material of Petermannia was misidentified, and now Petermanniaceae should no longer be considered a synonym of Colchicaceae. Arachnitis (Corsiaceae) falls into Liliales, but its exact position is not well supported. Sciaphila (Triuridaceae) falls with Pandanales. Trithuria (Hydatellaceae) falls in Poales near Eriocaulaceae, Mayacaceae, and Xyridaceae, but until a complete set of genes are produced for this taxon, its placement will remain problematic. Within the commelinid clade, Dasypogonaceae are sister to Poales and Arecales sister to the rest of the commelinids, but these relationships are only weakly supported
Genome characterization of brugmansia latent virus, a novel tobamovirus
A novel tobamovirus, brugmansia latent virus (BrLV), was discovered during a study of brugmansia (Brugmansia spp.) in the living collections held at the Royal Botanic Gardens, Kew. Here, we report the complete genome sequence of BrLV, which is 6,397 nucleotides long and contains the four open reading frames (RNA-dependent RNA polymerase, methyltransferase/helicase, movement, and coat proteins) typical of tobamoviruses. The complete genome sequence of BrLV shares 69.7% nucleotide sequence identity with brugmansia mild mottle virus (BrMMV) and 66.7 to 68.7% identity with other tobamoviruses naturally infecting members of the Solanaceae plant family. Phylogenetic analysis of the complete genome nucleotide sequence and the deduced amino acid sequences of the four tobamovirus proteins place BrLV in a subcluster with BrMMV within the Solanaceae-infecting tobamovirus subgroup as a new species
Phylogenetic inference of New Caledonian lineages of Sapindaceae: Molecular evidence requires a reassessment of generic circumscriptions
ACL-12-10International audienceSapindaceae (Sapindales) are a conspicuous and diversified element of the New Caledonian flora, with ca. 67 species (ca. 90 % endemic) in 13 genera (four endemic: Gongrodiscus, Loxodiscus, Podonephelium, Storthocalyx). The phylogeny of New Caledonian Sapindaceae is inferred by adding 97 new samples, encompassing the full distributional and morphological range of the archipelago's genera, to a broad plastid and nuclear DNA sequence dataset that is representative of the family worldwide. Results from phylogenetic analyses indicate that members of the family on New Caledonia belong to two major clades, the Dodonaea group (placed within subfamily Dodonaeoideae) and the Cupania group (subfamily Sapindoideae), which exhibit strikingly different species diversities (ca. 89% of the species on New Caledonia belong to the Cupania group). Results support the monophyly of all four endemic genera and most of those that also occur elsewhere, with the exception of the morphologically similar Austro-Pacific genera Arytera and Cupaniopsis, both of which have representatives in each of two well-supported subclades within the Cupania group, suggesting at least two dispersals to New Caledonia (most likely from Australia). The results provide a robust phylogenetic framework for ongoing taxonomic revisions of Sapindaceae genera on New Caledonia and for investigating the spatio-temporal history of the family in this biogeographically intriguing archipelago, although expanded sampling (including from other areas) and further analyses will be required to resolve generic limits among the taxa currently placed in Arytera and Cupaniopsis
Whole plastomes are not enough: phylogenomic and morphometric exploration at multiple demographic levels of the bee orchid clade Ophrys sect. Sphegodes.
Data from: Flower preferences and pollen transport networks for cavity nesting solitary bees: implications for the design of agri-environment schemes
Floral foraging resources are valuable for pollinator conservation on farmland, and their provision is encouraged by agri-environment schemes in many countries. Across Europe, wildflower seed mixtures are widely sown on farmland to encourage pollinators, but the extent to which key pollinator groups such as solitary bees exploit and benefit from these resources is unclear. We used high-throughput sequencing of 164 pollen samples extracted from the brood cells of 6 common cavity nesting solitary bee species (Osmia bicornis, Osmia caerulescens, Megachile versicolor, Megachile ligniseca, Megachile centuncularis and Hylaeus confususi) which are widely distributed across the UK and Europe. We documented their pollen use across 19 farms in southern England, UK, revealing their forage plants and examining the structure of their pollen transport networks. Of the 32 plant species included currently in sown wildflower mixes, 15 were recorded as present within close foraging range of the bees on the study farms, but only Ranunculus acris L. was identified within the pollen samples. Rosa canina L. was the most commonly found of the 23 plant species identified in the pollen samples, suggesting that, in addition to providing a nesting resource for Megachile leafcutter bees, it may be an important forage plant for these species. Higher levels of connectance and nestedness were characteristic of pollen transport networks on farms with abundant floral resources, which may increase resilience to species loss. Our data suggest that plant species promoted currently by agri-environment schemes are not optimal for solitary bee foraging. If a diverse community of pollinators is to be supported on UK and European farmland, additional species such as Rosa canina should be encouraged to meet the foraging requirements of solitary bees
Pollinator shifts as triggers of speciation in painted petal irises (Lapeirousia: Iridaceae).
BACKGROUND AND AIMS: Adaptation to different pollinators has been hypothesized as one of the main factors promoting the formation of new species in the Cape region of South Africa. Other researchers favour alternative causes such as shifts in edaphic preferences. Using a phylogenetic framework and taking into consideration the biogeographical scenario explaining the distribution of the group as well as the distribution of pollinators, this study compares pollination strategies with substrate adaptations to develop hypotheses of the primary factors leading to speciation in Lapeirousia (Iridaceae), a genus of corm-bearing geophytes well represented in the Cape and presenting an important diversity of pollination syndromes and edaphic preferences. METHODS: Phylogenetic relationships are reconstructed within Lapeirousia using nuclear and plastid DNA sequence data. State-of-the-art methods in biogeography, divergence time estimation, character optimization and diversification rate assessments are used to examine the evolution of pollination syndromes and substrate shifts in the history of the group. Based on the phylogenetic results, ecological factors are compared for nine sister species pairs in Lapeirousia. KEY RESULTS: Seventeen pollinator shifts and ten changes in substrate types were inferred during the evolution of the genus Lapeirousia. Of the nine species pairs examined, all show divergence in pollination syndromes, while only four pairs present different substrate types. CONCLUSIONS: The available evidence points to a predominant influence of pollinator shifts over substrate types on the speciation process within Lapeirousia, contrary to previous studies that favoured a more important role for edaphic factors in these processes. This work also highlights the importance of biogeographical patterns in the study of pollination syndromes
Phylogenetics of Liliales: summarized evidence from combined analyses of five plastid and one mitochondrial loci
Occurrence of prolactinoma after estrogen treatment in a girl with constitutional tall stature.
In order to investigate interfamilial relationships of Liliales we analyzed a combined matrix of plastid rbcL, trnL intron, trnL-F intergenic spacer, matK, and ndhF, and mitochondrial atp1 DNA sequences. The results are generally congruent with previous broad analyses and provide higher bootstrap support for many relationships. Important changes relative to previous studies are the recognition of Petermanniaceae distinct from Colchicaceae and the tentative inclusion of Corsiaceae in the order. This brings the number of families in the order from nine to eleven. The additional data presented here strengthen the case for including Uvulariaceae in Colchicaceae and Calochortaceae in Liliaceae