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The big‐bracted dogwood clade Benthamidia of Cornus is a typical example of the well‐known eastern Asia (EA) and North America (NA) floristic disjunction, with greater species diversity in EA than in NA. The lineage provides an opportunity to explore factors contributing to the plant diversity unevenness between EA and NA and test hypotheses on the origin of disjunct distribution from a phylogenetic perspective. We generated RAD‐seq data, conducted phylogenomic and biogeographic analyses for the clade with sampling of all species (9) and subspecies (10) currently recognized in floras. We also assessed species delineation and calculated phylogenetic diversity to evaluate the diversity unevenness between EA and NA. Finally, we examined variation of diversification rates and ecological niches on the phylogeny to explore potential causes underlying the observed diversity pattern. Our results revealed phylogenetic relationships congruent with previous studies and suggested a trans‐Beringian ancestral distribution of the clade Benthamidia in the mid‐Oligocene, dispersal from Mexico to eastern United States in the mid‐Miocene, and early diversification of the EA clade in SW China. Our results also confirmed greater phylogenetic diversity and diversification rate of the EA clade. Species delimitation analysis suggested 17 species in the clade Benthamidia, including all recognized subspecies. By integrating the results of molecular data with morphology, we proposed to retain the subspecies without changing their ranks. Our data suggested increased diversification rate in EA as an intrinsic factor explaining the greater species diversity in the region driven mainly by biogeographic isolation and partially by niche divergence. [ABSTRACT FROM AUTHOR]

Premise: A major goal of systematic biology is to uncover the evolutionary history of organisms and translate that knowledge into stable classification systems. Here, we integrate three sets of genome‐wide data to resolve phylogenetic relationships in Cornaceae (containing only Cornus s.l.), reconstruct the biogeographic history of the clade, and provide a revised classification using the PhyloCode to stabilize names for this taxonomically controversial group. Methods: We conducted phylogenetic analyses using 312 single‐copy nuclear genes and 70 plastid genes from Angiosperms353 Hyb‐Seq, plus numerous loci from RAD‐Seq. We integrated fossils using morphological data and produced a dated phylogeny for biogeographical analysis. Results: A well‐resolved, strongly supported, comprehensive phylogeny was obtained. Biogeographic analyses support an origin and rapid diversification of Cornus into four morphologically distinct major clades in the Northern Hemisphere (with an eastern Asian ancestor) during the late Cretaceous. Dispersal into Africa from eastern Asia likely occurred along the Tethys Seaway during the Paleogene, whereas dispersal into South America likely occurred during the Neogene. Diversification within the northern hemisphere likely involved repeated independent colonization of new areas during the Paleogene and Neogene along the Bering Land Bridge, the North Atlantic Land Bridge, and the Tethys Seaway. Thirteen strongly supported clades were named following rules of the PhyloCode. Conclusions: Our study provides an example of integrating genomic and morphological data to produce a robust, explicit species phylogeny that includes fossil taxa, which we translate into an updated classification scheme using the PhyloCode to stabilize names. [ABSTRACT FROM AUTHOR]

Restriction site‐associated DNA sequencing (RAD‐seq) enables obtaining thousands of genetic markers for phylogenomic studies. However, RAD‐seq data are subject to allele dropout (ADO) due to polymorphisms at enzyme cutting sites. We developed a new pipeline, RAD‐seq Allele Dropout Remedy in our study of the gymnosperm genus, Torreya, to mitigate ADO in outgroups by recovering missing loci from previously published transcriptomes. By using RADADOR to supplement Rad‐seq data in combination with plastome and mitochondrial gene sequences, morphology, and fossil records, we reconstructed the phylogenetic and biogeographic histories of the genus and tested hypotheses on anomalies of biodiversity of the eastern Asian‐North American floristic disjunction. Our results showed that our pipeline recovered many loci missing from the outgroup, and the improved data yielded a more robust phylogeny for Torreya. Using the fossilized birth–death model and divergence–extinction–cladogenesis method, we resolved a detailed biogeographic history of Torreya that suggested a Jurassic origin spanning Laurasia and differential speciation and extinction among continents accounting for modern diversity, which is biased toward eastern Asia (EA). The biogeographic results also supported a vicariance origin of modern Torreya from a widespread ancestor in EA and North America (NA) in the mid‐Eocene, and cross Beringian exchange in the early Paleogene before the vicariant isolation, in contrast to the "out of NA" pattern common to gymnosperms and to the "out of EA" hypothesis previously proposed for the genus. Furthermore, we observed phylogenetic discordance between the nuclear and plastid phylogenies for Torreya jackii, suggesting differential lineage sorting of plastid genomes among species of Torreya or plastid genome capture in T. jackii. [ABSTRACT FROM AUTHOR]

Premise: Large disjunctions in species distributions provide excellent opportunities to study processes that shape biogeographic patterns. One such disjunction is the eastern Asia–eastern North America (EA‐ENA) floristic disjunction. For many genera with this disjunction, species richness is greater in EA than in ENA; this pattern has been attributed, in part, to higher rates of molecular evolution and speciation in EA. Longer branch lengths have been found in some EA clades, relative to their ENA sister clades, suggesting that the EA lineages have evolved at a higher rate, possibly due to environmental heterogeneity, potentially contributing to the species richness anomaly. Methods: To evaluate whether rates of molecular evolution are elevated in EA relative to ENA, we used transcriptomes from species in 11 genera displaying this disjunction. Rates of molecular evolution were estimated for up to 385 orthologous nuclear loci per genus. Results: No statistically significant differences were identified in pairwise comparisons between EA and ENA sister species, suggesting equal rates of molecular evolution for both species; the data also suggest similar selection pressures in both regions. For larger genera, evidence likewise argues against more species‐rich clades having higher molecular evolutionary rates, regardless of region. Our results suggest that genes across multiple gene ontology categories are evolving at similar rates under purifying selection in species in both regions. Conclusions: Our data support the hypothesis that greater species richness in EA than ENA is due to factors other than an overall increase in rates of molecular evolution in EA. [ABSTRACT FROM AUTHOR]

Nyssa (Nyssaceae, Cornales) represents a classical example of the well‐known eastern Asian–eastern North American floristic disjunction. The genus consists of three species in eastern Asia, four species in eastern North America, and one species in Central America. Species of the genus are ecologically important trees in eastern North American and eastern Asian forests. The distribution of living species and a rich fossil record of the genus make it an excellent model for understanding the origin and evolution of the eastern Asian–eastern North American floristic disjunction. However, despite the small number of species, relationships within the genus have remained unclear and have not been elucidated using a molecular approach. Here, we integrate data from 48 nuclear genes, fossils, morphology, and ecological niche to resolve species relationships, elucidate its biogeographical history, and investigate the evolution of morphology and ecological niches, aiming at a better understanding of the well‐known EA–ENA floristic disjunction. Results showed that the Central American (CAM) Nyssa talamancana was sister to the remaining species, which were divided among three, rapidly diversified subclades. Estimated divergence times and biogeographical history suggested that Nyssa had an ancestral range in Eurasia and western North America in the late Paleocene. The rapid diversification occurred in the early Eocene, followed by multiple dispersals between and within the Erasian and North American continents. The genus experienced two major episodes of extinction in the early Oligocene and end of Neogene, respectively. The Central American N. talamancana represents a relic lineage of the boreotropical flora in the Paleocene/Eocene boundary that once diversified in western North America. The results supported the importance of both the North Atlantic land bridge and the Bering land bridge (BLB) for the Paleogene dispersals of Nyssa and the Neogene dispersals, respectively, as well as the role of Central America as refugia of the Paleogene flora. The total‐evidence‐based dated phylogeny suggested that the pattern of macroevolution of Nyssa coincided with paleoclimatic changes. We found a number of evolutionary changes in morphology (including wood anatomy and leaf traits) and ecological niches (precipitation and temperature) between the EA–ENA disjunct, supporting the ecological selection driving trait evolutions after geographic isolation. We also demonstrated challenges in phylogenomic studies of lineages with rapid diversification histories. The concatenation of gene data can lead to inference of strongly supported relationships incongruent with the species tree. However, conflicts in gene genealogies did not seem to impose a strong effect on divergence time dating in our case. Furthermore, we demonstrated that rapid diversification events may not be recovered in the divergence time dating analysis using BEAST if critical fossil constraints of the relevant nodes are not available. Our study provides an example of complex bidirectional exchanges of plants between Eurasia and North America in the Paleogene, but "out of Asia" migrations in the Neogene, to explain the present disjunct distribution of Nyssa in EA and ENA. [ABSTRACT FROM AUTHOR]

Understanding the consequences of exotic diseases on native forests is important to evolutionary ecology and conservation biology because exotic pathogens have drastically altered US eastern deciduous forests. Cornus florida L. (flowering dogwood tree) is one such species facing heavy mortality. Characterizing the genetic structure of C. florida populations and identifying the genetic signature of adaptation to dogwood anthracnose (an exotic pathogen responsible for high mortality) remain vital for conservation efforts. By integrating genetic data from genotype by sequencing (GBS) of 289 trees across the host species range and distribution of disease, we evaluated the spatial patterns of genetic variation and population genetic structure of C. florida and compared the pattern to the distribution of dogwood anthracnose. Using genome‐wide association study and gradient forest analysis, we identified genetic loci under selection and associated with ecological and diseased regions. The results revealed signals of weak genetic differentiation of three or more subgroups nested within two clusters—explaining up to 2%–6% of genetic variation. The groups largely corresponded to the regions within and outside the eastern Hot‐Continental ecoregion, which also overlapped with areas within and outside the main distribution of dogwood anthracnose. The fungal sequences contained in the GBS data of sampled trees bolstered visual records of disease at sampled locations and were congruent with the reported range of Discula destructiva, suggesting that fungal sequences within‐host genomic data were informative for detecting or predicting disease. The genetic diversity between populations at diseased vs. disease‐free sites across the range of C. florida showed no significant difference. We identified 72 single‐nucleotide polymorphisms (SNPs) from 68 loci putatively under selection, some of which exhibited abrupt turnover in allele frequencies along the borders of the Hot‐Continental ecoregion and the range of dogwood anthracnose. One such candidate SNP was independently identified in two prior studies as a possible L‐type lectin‐domain containing receptor kinase. Although diseased and disease‐free areas do not significantly differ in genetic diversity, overall there are slight trends to indicate marginally smaller amounts of genetic diversity in disease‐affected areas. Our results were congruent with previous studies that were based on a limited number of genetic markers in revealing high genetic variation and weak population structure in C. florida. [ABSTRACT FROM AUTHOR]

The eastern Asian (EA)–eastern North American (ENA) floristic disjunction represents a major pattern of phytogeography of the Northern Hemisphere. Despite 20 years of studies dedicated to identification of taxa that display this disjunct pattern, its origin and evolution remain an open question, especially regarding post‐isolation evolution. The blue‐ or white‐fruited dogwoods (BW) are the most species‐rich among the four major clades of Cornus L., consisting of ~35 species divided into three subgenera (subg. Yinquania, subg. Mesomora, and subg. Kraniopsis). The BW group provides an excellent example of the EA–ENA floristic disjunction for biogeographic study due to its diversity distribution centered in eastern Asia and eastern North America, yet its species relationships and delineation have remained poorly understood. In this study, we combined genome‐wide markers from RAD‐seq, morphology, fossils, and climate data to understand species relationships, biogeographic history, and ecological niche and morphological evolution. Our phylogenomic analyses with RAxML and MrBayes recovered a strongly supported and well‐resolved phylogeny of the BW group with three intercontinental disjunct clades in EA and ENA or Eurasia and North America, of which two are newly identified within subg. Kraniopsis. These analyses also recovered a potential new species but failed to resolve relationships within the C. hemsleyi–C. schindleri complex. In an effort to develop an approach to reduce computation time, analysis of different nodal age settings in treePL suggests setting a node's minimum age constraint to the lower bound of a fossil's age range to obtain similar ages to that of BEAST. Divergence time analyses with BEAST and treePL dated the BW stem back to the very Late Cretaceous and the divergence of the three subgenera in the Paleogene. By integrating fossil ages and morphology, a total evidence‐based dating approach was used in conjunction with time‐slice probabilities of dispersal under a DEC model to resolve ancestral ranges of each disjunct in the Miocene: Eurasia and ENA (disjunct 1), EA and western North America (disjunct 2), and EA (disjunct 3). The dated biogeographic history supports dispersal via the North Atlantic Land Bridge in the late Paleogene in disjunct 1 and dispersal via the Bering Land Bridge in the Miocene for disjuncts 2 and 3. Character mapping with a stochastic model in phytools and comparison of ecological niche, morphospace, and rate of evolution indicated differential divergence patterns in morphology, ecological niche, and molecules between disjunct sisters. Although morphological stasis was observed in most of the characters, evolutionary changes in growth habit and some features of leaf, flower, and fruit morphology occurred in one or both sister clades. A significant differentiation of ecological habitats in temperature, precipitation, and elevation between disjunct sisters was observed, suggesting a role of niche divergence in morphological evolution post‐isolation. The patterns of evolutionary rate between morphology and molecules varied among disjunct clades and were not always congruent between morphology and molecules, suggesting cases of non‐neutral morphological evolution driven by ecological selection. Our phylogenetic evidence and comparisons of evolutionary rate among disjunct lineages lend new insights into the formation of the diversity anomaly between EA and ENA, with particular support of an early diversification in EA. These findings, in conjunction with previous studies, again suggest that the EA–ENA disjunct floras are an assembly of lineages descended from the Mesophytic Forests that evolved from the early Paleogene "boreotropical flora" through varied evolutionary pathways across lineages. [ABSTRACT FROM AUTHOR]

Abstract: Understanding intraspecific relationships between genetic and functional diversity is a major goal in the field of evolutionary biology and is important for conserving biodiversity. Linking intraspecific molecular patterns of plants to ecological pressures and trait variation remains difficult due to environment‐driven plasticity. Next‐generation sequencing, untargeted liquid chromatography–mass spectrometry (LC‐MS) profiling, and interdisciplinary approaches integrating population genomics, metabolomics, and community ecology permit novel strategies to tackle this problem. We analyzed six natural populations of the disease‐threatened Cornus florida L. from distinct ecological regions using genotype‐by‐sequencing markers and LC‐MS‐based untargeted metabolite profiling. We tested the hypothesis that higher genetic diversity in C. florida yielded higher chemical diversity and less disease susceptibility (screening hypothesis), and we also determined whether genetically similar subpopulations were similar in chemical composition. Most importantly, we identified metabolites that were associated with candidate loci or were predictive biomarkers of healthy or diseased plants after controlling for environment. Subpopulation clustering patterns based on genetic or chemical distances were largely congruent. While differences in genetic diversity were small among subpopulations, we did observe notable similarities in patterns between subpopulation averages of rarefied‐allelic and chemical richness. More specifically, we found that the most abundant compound of a correlated group of putative terpenoid glycosides and derivatives was correlated with tree health when considering chemodiversity. Random forest biomarker and genomewide association tests suggested that this putative iridoid glucoside and other closely associated chemical features were correlated to SNPs under selection. [ABSTRACT FROM AUTHOR]

Angiosperms evolved a great diversity of ways to display their flowers for reproductive success by variation in floral color, size, shape, scent, arrangements, and flowering time. The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences can drive new ecological adaptations, speciation, and angiosperm diversification. Evolutionary developmental biology (evo-devo) seeks to uncover the developmental and genetic basis underlying morphological diversification. Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution. A number of regulatory genes controlling floral and inflorescence development have been identified in model plants (e.g., Arabidopsis thaliana, Antirrhinum majus) using forward genetics and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics. Gene-regulatory networks that mediated the developmental progresses of floral and inflorescence development have also been established in some plant species. Meanwhile, phylogeny-based comparative analysis of morphological and genetic character has enabled the identification of key evolutionary events that lead to morphological complexity and diversification. Here we review the recent progress on evo-devo studies of floral display including floral symmetry, petal fusion, floral color, floral scent, and inflorescences. We also review the molecular genetic approaches applied to plant evo-devo studies and highlight the future directions of evo-devo. [ABSTRACT FROM AUTHOR]

In mature buds of the dwarf dogwood lineage (DW) of Cornus, petals and filaments form an 'x'-like box containing mechanical energy from the filaments to allow explosive pollen dispersal. As a start to understand the molecular mechanisms responsible for the origin of this unique structure in Cornus, we cloned and characterized the sequences of APETALA3 ( AP3) homologs from Cornus canadensis of the DW lineage and five other Cornus species, given the function of AP3 on petal and stamen development in Arabidopsis, and tested the function of CorcanAP3 using a stable Agrobacterium-mediated transformation system. The cloned CorAP3s ( AP3-like genes in Cornus) were confirmed to belong to the euAP3 lineage. qRT-PCR analysis indicated strong increase of CorcanAP3 expression in floral buds of wildtype C. canadensis. A hairpin construct of CorcanAP3 was successfully introduced into wild type plants of C. canadensis, resulting in significant reduction of CorcanAP3 expression and abnormal floral development. The abnormal floral buds lost the 'x' form and opened immaturely due to delay or retard of petal and stamen elongation and the push of style elongation. The results suggested CorcanAP3 may function to regulate the coordinated rate of development of petals and stamens in C. canadensis, necessary for the x-structure formation, although the exact molecular mechanism remains unclear. Comparison among six Cornus species indicated a greater ratio of stamen to petal and style growth in C. canadensis, suggesting an evolutionary change of CorAP3 expression pattern in the DW lineage, leading to the greater growth of filaments to form the 'x'-box. [ABSTRACT FROM AUTHOR]

TFL1-, AP1- and LFY-like genes are known to be key regulators of inflorescence development. However, it remains to be tested whether the evolutionary modifications of inflorescence morphology result from shifts in their expression patterns., We compared the spatiotemporal expression patterns of Cor TFL1, Cor AP1 and Cor LFY in six closely related Cornus species that display four types of closed inflorescence morphology using quantitative real-time polymerase chain reaction ( qRT- PCR) and RNA in situ hybridization. Character mapping on the phylogeny was conducted to identify evolutionary changes and to assess the correlation between changes in gene expression and inflorescence morphology., Results demonstrated variation of gene expression patterns among species and a strong correlation between Cor TFL1 expression and the branch index of the inflorescence type. Evolutionary changes in Cor TFL1 and Cor AP1 expression co-occurred on the phylogeny with the morphological changes underpinning inflorescence divergence., The study found a clear correlation between the expression patterns of Cor TFL1 and Cor AP1 and the inflorescence architecture in a natural system displaying closed inflorescences. The results suggest a role for the alteration in Cor TFL1 and Cor AP1 expression during the evolutionary modification of inflorescences in Cornus. We propose that a TFL1-like and AP1-like gene-based model may explain variation of closed inflorescences in Cornus and other lineages. [ABSTRACT FROM AUTHOR]

Discovering local adaptation, its genetic underpinnings, and environmental drivers is important for conserving forest species. Ecological genomic approaches coupled with next-generation sequencing are useful means to detect local adaptation and uncover its underlying genetic basis in nonmodel species. We report results from a study on flowering dogwood trees ( Cornus florida L.) using genotyping by sequencing ( GBS). This species is ecologically important to eastern US forests but is severely threatened by fungal diseases. We analyzed subpopulations in divergent ecological habitats within North Carolina to uncover loci under local selection and associated with environmental-functional traits or disease infection. At this scale, we tested the effect of incorporating additional sequencing before scaling for a broader examination of the entire range. To test for biases of GBS, we sequenced two similarly sampled libraries independently from six populations of three ecological habitats. We obtained environmental-functional traits for each subpopulation to identify associations with genotypes via latent factor mixed modeling ( LFMM) and gradient forests analysis. To test whether heterogeneity of abiotic pressures resulted in genetic differentiation indicative of local adaptation, we evaluated Fst per locus while accounting for genetic differentiation between coastal subpopulations and Piedmont-Mountain subpopulations. Of the 54 candidate loci with sufficient evidence of being under selection among both libraries, 28-39 were Arlequin-BayeScan Fst outliers. For LFMM, 45 candidates were associated with climate (of 54), 30 were associated with soil properties, and four were associated with plant health. Reanalysis of combined libraries showed that 42 candidate loci still showed evidence of being under selection. We conclude environment-driven selection on specific loci has resulted in local adaptation in response to potassium deficiencies, temperature, precipitation, and (to a marginal extent) disease. High allele turnover along ecological gradients further supports the adaptive significance of loci speculated to be under selection. [ABSTRACT FROM AUTHOR]

The p-type (Bi,Sb)2Te3 bulks are prepared from ball-milling powders by resistance pressure sintering method and their thermoelectric properties are investigated as a function of ball milling time. Prolonging milling time would introduce more anti-site defects, interaction of vacancies and antisite defect, grain-boundaries and interface defects, leading to lower carrier concentration and mobility. The peak value of ZT = 1.0 is achieved at 300 K for the 5 h sample. When the testing temperature is over 323 K, the ZT value of the 0 h sample is higher than that of the 5 h sample. The effect of porosity on the thermoelectric properties is also investigated by effective medium theory. As the porosity increased, the electrical resistivity increases and the thermal conductivity decrease. [ABSTRACT FROM AUTHOR]

Repeated global climatic cooling and warming cycles during the Pleistocene played a major role in the distribution and evolution of the Earth biota. Here, we integrate phylogeography, coalescent-based Bayesian estimation of demographic history, and species distribution modeling (SDM) to understand the genetic patterns and biogeography of the flowering dogwood, Cornus florida subsp. florida L., since the Last Glacial Maximum (LGM). Natural populations of the species are severely threatened by dogwood anthracnose. We genotyped 306 plants from 73 locations of the species across most of its native distribution with three DNA regions from the plastid genome, ndhF-rpl32, rps16 and trnQ-rps16. The genealogy and haplotype network reconstruction revealed two haplotype lineages diverging ≈3.70 million years ago. We detected no clear geographic structuring of genetic variation, although significant local structure appeared to be evident, likely due to a combination of substantial localized seed dispersal by small mammals and small population size/limited sampling at a location. The spatial distribution of haplotype frequencies, estimated population demographic history, and results from hindcasting analysis using SDM suggested refugia in southeastern North America and population reduction during the LGM, followed by rapid post-glacial expansion to the north. Forecasting analysis using SDM predicted range shifts to the north under ongoing global warming. Our results further suggested that gene flow via seed dispersal has been high but insufficient to counter the effect of genetic drift. This study demonstrates the benefit of integrating genetic data and species distribution modeling to obtain corroborative evidence in elucidating recent biogeographic history and understanding of genetic patterns and species evolution. [ABSTRACT FROM AUTHOR]

Fothergilla (Hamamelidaceae) consists of Fothergilla gardenii (4 x) from the coastal plains of the southeastern USA, F. major (6 x) from the piedmont and mountains of the same region, and a few allopatric diploid populations of unknown taxonomic status. The objective of this study was to explore the relationships of the polyploid species with the diploid plants. Genotyping by sequencing (GBS) was applied to generate genome-wide molecular markers for phylogenetic and genetic structure analyses of 36 accessions of Fothergilla. Sanger sequencing of three plastid and one nuclear regions provided data for comparison with GBS-based results. Phylogenetic outcomes were compared using data from different sequencing runs and different software workflows. The different data sets showed substantial differences in inferred phylogenies, but all supported a genetically distinct 6 x F. major and two lineages of the diploid populations closely associated with the 4 x F. gardenii. We hypothesize that the 4 x F. gardenii originated through hybridization between the Gulf coastal 2 x and an extinct (or undiscovered) 2 x lineage, followed by backcrosses to the Atlantic coastal 2 x before chromosome doubling, and the 6 x F. major also originated from the 'extinct' 2 x lineage. Alternative scenarios are possible but are not as well supported. The origins and divergence of the polyploid species likely occurred during the Pleistocene cycles of glaciation, although fossil evidence indicates the genus might have existed for a much longer time with a wider past distribution. Our study demonstrates the power of combining GBS data with Sanger sequencing in reconstructing the evolutionary network of polyploid lineages. [ABSTRACT FROM AUTHOR]

Genome size variation is of fundamental biological importance and has been a longstanding puzzle in evolutionary biology. Several hypotheses for genome size evolution including neutral, maladaptive, and adaptive models have been proposed, but the relative importance of these models remains controversial., Primulina is a genus that is highly diversified in the Karst region of southern China, where genome size variation and the underlying evolutionary mechanisms are poorly understood. We reconstructed the phylogeny of Primulina using DNA sequences for 104 species and determined the genome sizes of 101 species. We examined the phylogenetic signal in genome size variation, and tested the fit to different evolutionary models and for correlations with variation in latitude and specific leaf area ( SLA)., The results showed that genome size, SLA and latitudinal variation all displayed strong phylogenetic signals, but were best explained by different evolutionary models. Furthermore, significant positive relationships were detected between genome size and SLA and between genome size and latitude., Our study is the first to investigate genome size evolution on such a comprehensive scale and in the Karst region flora. We conclude that genome size in Primulina is phylogenetically conserved but its variation among species is a combined outcome of both neutral and adaptive evolution. [ABSTRACT FROM AUTHOR]

Philadelphus (Hydrangeaceae) comprises 60 or fewer species distributed disjunctly in eastern Asia, eastern and western North America to Central America, and southeastern Europe and western Asia. The genus is highly valued in horticulture, but poorly understood regarding taxonomy, species relationships, and biogeographic history. The present study was the first phylogenetic and biogeographic analysis of Philadelphus using both nuclear and chloroplast DNA markers to evaluate classification schemes and to elucidate the biogeographic origin. Our results suggest that Philadelphus is a paraphyletic group with the monotypic genus Carpenteria nested within. Three major lineages were identified in the Philadelphus-Carpenteria clade, each strongly supported by the molecular data. Biogeographic analysis using the Bayes-DIVA method (implemented in the newly developed RASP) and divergence time dating with BEAST resolved the origin and early diversification of Philadelphus s.l. (including Carpenteria) in western North America (including Mexico) in the Eocene. The lineage diversified and subsequently spread into Asia and other areas in the late Tertiary or Neogene to obtain a worldwide distribution. The study adds an additional example of an 'out of western North America' migration in the phylogeographic history of the northern hemisphere. [ABSTRACT FROM AUTHOR]

The arcto-Tertiary relictual flora is comprised of many genera that occur non-contiguously in the temperate zones of eastern Asia, Europe, eastern North America, and western North America. Within each distributional area, species are typically endemic and may thus be widely separated from closely related species within the other areas. It is widely accepted that this common pattern of distribution resulted from of the fragmentation of a once more-continuous arcto-Tertiary forest. The historical biogeographic events leading to the present-day disjunction have often been investigated using a phylogenetic approach. Limitations to these previous studies have included phylogenetic uncertainty and uncertainty in ancestral range reconstructions. However, the recently described Bayes-DIVA method handles both types of uncertainty. Thus, we used Bayes-DIVA analysis to reconstruct the stem lineage distributions for 185 endemic lineages from 23 disjunct genera representing 17 vascular plant families. In particular, we asked whether endemic lineages within each of the four distributional areas more often evolved from (1) widespread ancestors, (2) ancestors dispersed from other areas, or (3) endemic ancestors. We also considered which of these three biogeographic mechanisms may best explain the origins of arcto-Tertiary disjunct endemics in the neotropics. Our results show that eastern Asian endemics more often evolved from endemic ancestors compared to endemics in Europe and eastern and western North America. Present-day endemic lineages in the latter areas more often arose from widespread ancestors. Our results also provide anecdotal evidence for the importance of dispersal in the biogeographic origins of arcto-Tertiary species endemic in the neotropics. [ABSTRACT FROM AUTHOR]

Establishing the phylogenetic and demographic history of rare plants improves our understanding of mechanisms that have led to their origin and can lead to valuable insights that inform conservation decisions. The Atlantic coastal plain of eastern North America harbours many rare and endemic species, yet their evolution is poorly understood. We investigate the rare Sandhills lily ( Lilium pyrophilum), which is endemic to seepage slopes in a restricted area of the Atlantic coastal plain of eastern North America. Using phylogenetic evidence from chloroplast, nuclear internal transcribed spacer and two low-copy nuclear genes, we establish a close relationship between L. pyrophilum and the widespread Turk's cap lily, L. superbum. Isolation-with-migration and coalescent simulation analyses suggest that (i) the divergence between these two species falls in the late Pleistocene or Holocene and almost certainly post-dates the establishment of the edaphic conditions to which L. pyrophilum is presently restricted, (ii) vicariance is responsible for the present range disjunction between the two species, and that subsequent gene flow has been asymmetrical and (iii) L. pyrophilum harbours substantial genetic diversity in spite of its present rarity. This system provides an example of the role of edaphic specialization and climate change in promoting diversification in the Atlantic coastal plain. [ABSTRACT FROM AUTHOR]

Thiophene-2,5-dicarboxylic acid, benzene-1,3-dicarboxylic acid, or furan-2,5-di-carboxylic acid, respectively, reacted with various β-amino alcohols in toluene under reflux within 24 h, to form nine bis(oxazoline)s (-) in good yields through water deprivation via a one-pot reaction. The synthetic method is facile and efficient and deserves great application potentials in the research and development in the area of bis(oxazoline)s. J. Heterocyclic Chem., (2010). [ABSTRACT FROM AUTHOR]

The general phylogeographical paradigm for eastern North America (ENA) is that many plant and animal species retreated into southern refugia during the last glacial period, then expanded northward after the last glacial maximum (LGM). However, some taxa of the Gulf and Atlantic Coastal Plain (GACP) demonstrate complex yet recurrent distributional patterns that cannot be explained by this model. For example, eight co-occurring endemic plant taxa with ranges from New York to South Carolina exhibit a large disjunction separating northern and southern populations by >300 km. Pyxidanthera (Diapensiaceae), a plant genus that exhibits this pattern, consists of two taxa recognized as either species or varieties. We investigated the taxonomy and phylogeography of Pyxidanthera using morphological data, cpDNA sequences, and amplified fragment length polymorphism markers. Morphological characters thought to be important in distinguishing Pyxidanthera barbulata and P. brevifolia demonstrate substantial overlap with no clear discontinuities. Genetic differentiation is minimal and diversity estimates for northern and southern populations of Pxyidanthera are similar, with no decrease in rare alleles in northern populations. In addition, the northern populations harbour several unique cpDNA haplotypes. Pyxidanthera appears to consist of one morphologically variable species that persisted in or near its present range at least through the latter Pleistocene, while the vicariance of the northern and southern populations may be comparatively recent. This work demonstrates that the refugial paradigm is not always appropriate and GACP endemic plants, in particular, may exhibit phylogeographical patterns qualitatively different from those of other ENA plant species. [ABSTRACT FROM AUTHOR]

Knowledge regarding the origin and maintenance of hybrid zones is critical for understanding the evolutionary outcomes of natural hybridization. To evaluate the contribution of historical contact vs. long-distance gene flow in the formation of a broad hybrid zone in central and northern Georgia that involves Aesculus pavia, A. sylvatica, and A. flava, three cpDNA regions (matK, trnD-trnT, and trnH-trnK) were analyzed. The maternal inheritance of cpDNA in Aesculus was confirmed via sequencing of matK from progeny of controlled crosses. Restriction site analyses identified 21 unique haplotypes among 248 individuals representing 29 populations from parental species and hybrids. Haplotypes were sequenced for all cpDNA regions. Restriction site and sequence data were subjected to phylogeographic and population genetic analyses. Considerable cpDNA variation was detected in the hybrid zone, as well as ancestral cpDNA polymorphism; furthermore, the distribution of haplotypes indicates limited interpopulation gene flow via seeds. The genealogy and structure of genetic variation further support the historical presence of A. pavia in the Piedmont, although they are at present locally extinct. In conjunction with previous allozyme studies, the cpDNA data suggest that the hybrid zone originated through historical local gene flow, yet is maintained by periodic long-distance pollen dispersal. [ABSTRACT FROM AUTHOR]

DNA sequences were generated for matK and ITS for 68 and 103 samples of Cornus to reconstruct a species level phylogeny of the genus. The results support the monophyly of most subgenera, except subg. Kraniopsis and subg. Cornus. Subgenus Kraniopsis was suggested to exclude C. peruviana from South America and subg. Afrocrania and subg. Sinocornus were nested within subg. Cornus. Four major clades corresponding to groups also recognizable by morphological differences were revealed: the big-bracted dogwoods (BB) including subg. Cynoxylon, subg. Syncarpea, and subg. Discocrania, the dwarf dogwoods (DW) including subg. Arctocrania, the cornelian cherries (CC) including subg. Cornus, subg. Sinocornus, and subg. Afrocrania, and the blue- or white-fruited dogwoods (BW) including subg. Kraniopsis, subg. Mesomora, and subg. Yinquania. This finding is consistent with previous studies with more limited sampling. The single South American species C. peruviana was found to be sister to the Asian C. oblonga of subg. Yinquania, adding a fourth intercontinental disjunction in the genus that was previously unknown. Species relationships within the subgenera were clearly resolved except for the relatively large subg. Syncarpea and subg. Kraniopsis. Phylogenetic analyses of total evidence combining morphology, matK, ITS, and previously published rbcL and 26S rDNA sequences resolved the relationships among subgenera as (BW(CC(BB,DW))). Biogeographic analyses using DIVA with or without fossils resulted in different inferences of biogeographic history of the genus, indicating the importance of fossil data in biogeographic analyses. The phylogeny based on the total evidence tree including fossils supports an origin and early Tertiary diversification of Cornus in Europe and multiple trans-Atlantic migrations between Europe and North America by the early Tertiary. It also supports that distribution of the few species in the southern hemisphere was not ancestral, but a result of migration from the north. This evidence rejects a previous hypothesis of a southern hemispheric origin of the genus. [ABSTRACT FROM AUTHOR]

Deals with a study which examined phylogenetic relationships and the evolution of Chrysosplenium using matK sequence data. Materials and methods; Results; Discussion.

Provides information concerning the botanical aspects involving the Saxifraga svalbardensis. What the data suggested; Information on the related species of the saxifraga and svalbard; Analysis of fifteen populations.

Provides information on a study using comparative matK sequencing to elucidate further relationships within Cornales. Methodology and materials used to conduct the study; Results of the study; Discussion on the results.

An introduction is presented in which the editor discusses various reports within the issue on topics including plant phylogeny, plant morphology and plant evolution.

The article explores the origins of polyploid Fothergilla (Hamamelidaceae) collected from southeastern U.S. and their evolutionary relationships with the diploid plants. It cites the application of genotyping by sequencing (GBS) to produce the molecular markers, the phylogenetic and genetic structure analyses of accessions of Fothergilla which include F. gardenii and F. major, the substantial differences in inferred phylogenies, and the power of combining GBS data with Sanger sequencing.

Despite increasing interest in the molecular mechanisms of floral diversity, few studies have investigated the developmental and genetic bases of petaloid bracts. This study examined morphological patterns of bract initiation and expression patterns of B-class MADS-box genes in bracts of several Cornus species. We suggest that petaloid bracts in this genus may not share a single evolutionary origin., Developmental pathways of bracts and spatiotemporal expression of B-class genes in bracts and flowers were examined for four closely related dogwood species., Divergent morphological progressions and gene expression patterns were found in the two sister lineages with petaloid bracts, represented by Cornus florida and Cornus canadensis. Phylogeny-based analysis identified developmental and gene expression changes that are correlated with the evolution of petaloid bracts in C. florida and C. canadensis., Our data support the existence of independent evolutionary origins of petaloid bracts in C. canadensis and C. florida. Additionally, we suggest that functional transference within B-class gene families may have contributed to the origin of bract petaloidy in C. florida. However, the underlying mechanisms of petaloid bract development likely differ between C. florida and C. canadensis. In the future this hypothesis can be tested by functional analyses of Cornus B-class genes. [ABSTRACT FROM AUTHOR]

Purpose: Increasing evidence indicates that neuroinflammation plays a critical role in the pathogenesis of mesial temporal lobe epilepsy (MTLE). The aim of this study was to investigate the dynamic expression of interleukin (IL)-1β as a proinflammatory cytokine and microRNA (miR)-146a as a posttranscriptional inflammation-associated microRNA (miRNA) in the hippocampi of an immature rat model and children with MTLE. Methods: To study the expression of IL-1β and miR-146a, we performed a reverse transcription polymerase chain reaction, Western blot, and real-time quantitative PCR on the hippocampi of immature rats at 11 days of age. Expression was monitored in the acute, latent, and chronic stages of disease (2 h and 3 and 8 weeks after induction of lithium-pilocarpine status epilepticus, respectively), and in control hippocampal tissues corresponding to the same timeframes. Similar expression methods were applied to hippocampi obtained from children with MTLE and normal controls. Key Findings: The expression of IL-1β and miR-146a in both children and immature rats with MTLE differs according to the stage of MTLE development. Both IL-1β and miR-146a are significantly up-regulated, but in opposite ways: IL-1β expression is highest in the acute stage, when expression of miR-146a is at its lowest level; miR-146a expression is highest in the latent stage, when IL-1β expression is at its lowest level. Both IL-1β and miR-146a are up-regulated in the chronic stage, but not as much as in the other stages. Significance: Our study is the first to focus on the expression of miR-146a in the immature rat model of lithium-pilocarpine MTLE and in children with MTLE. We have detected that the expression of proinflammatory cytokine IL-1β and posttranscriptional inflammation-associated miR-146a is variable depending on the disease stage. Furthermore, both IL-1β and miR-146a are up-regulated in immature rats and children with MTLE. Our findings elucidate the role of inflammation in the pathogenesis of MTLE in the immature rat model and children. Therefore, modulation of the IL-1β-miR-146a axis may be a novel therapeutic target in the treatment of MTLE. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C6H4Br2ClN, all atoms but Br are located on a crystallographic mirror plane. The crystal packing is stabilized by offset π–π stacking. [ABSTRACT FROM AUTHOR]