The introduction of an invasive weed was not followed by the introduction of ethnobotanical knowledge: a review on the ethnobotany of Centaurea solstitialis L. (Asteraceae)

Invasive plants are known for their impacts to ecosystems and societies, but their potential cultural use tend to be unexplored. One important mechanism of plant invasion is the use of “allelochemicals” or “novel weapons”: chemical defenses which are new to their invaded habitats and that confer them competitive advantages. However, these chemicals are precisely what confers them ethnobotanical and medicinal properties. We reviewed the literature assessing the biogeography of the cultural uses of the model invasive plant yellow-starthistle (Centaurea solstitialis L.; Asteraceae), and assessed the extent to which the introduction of a weed native to Eurasia into several non-native world regions was paralleled by the spread of cultural uses from its native range. We found that the species was rich in pharmaceutically active compounds and that the species had been traditionally used for medicinal purposes, as raw material, and as food. However, ethnobotanical uses were reported almost exclusively in its native range, with no uses described for the non-native range, apart from honey production in California, Argentina, and Australia. Our study exemplifies how, when plant introductions are not paralleled synchronously by significant human migrations, cultural adoption can be extremely slow, even within the native range of the species. Invasive species can provide real-time insights into the cultural processes by which humans learn to use plants. This case study highlights how biological invasions and cultural expansions can be subjected to different constraints

Physico-Chemical Characterization of Some Diquaternary Salts of 4,4\u27-Bipyridine

The paper presents a study on the physicochemical properties of some new symmetrical diquaternary salts of 4,4\u27-bipyridine. The properties refer to the acid-basic and thermal behavior of these compounds. The chemical stability of these salts in solution was found to be pH dependant. Thus, in the basic medium they converted into amphionic compounds of the N-ylide type and the equilibrium between salt (acid character) and N-ylide (basic character) was observed. The acid-basic equilibrium was made evident by pH-meter titrations. The thermal stability was studied by the thermogravimetric analysis under dynamic temperature conditions. The complexity of degradation as a consequence of chemical structure was revealed and the kinetic and thermodynamic parameters of the degradation were determined

Experimental admixture among geographically disjunct populations of an invasive plant yields a global mosaic of reproductive incompatibility and heterosis

1. Invasive species have the ability to rapidly adapt in the new regions where they are introduced. Classic evolutionary theory predicts that the accumulation of genetic differences over time in allopatric isolation may lead to reproductive incompatibilities resulting in decreases in reproductive success and, eventually, to speciation. However, experimental evidence for this theoretical prediction in the context of invasive species is lacking. We aimed to test for the potential of allopatry to determine reproductive success of invasive plants, by experimentally admixing genotypes from six different native and non‐native regions of Centaurea solstitialis, an invasive forb for which preliminary studies have detected some degree of reproductive isolation between one native and non‐native region. 2. We grew plants under common garden conditions and outcrossed individuals originating from different source populations in the native and introduced range to evaluate reproductive success in terms of seed to ovule ratio produced. We also assessed geographical and genetic isolation among C. solstitialis regions as a potential driving factor of reproductive success. 3. Experimental admixture generated mixed fitness effects, including significant increases, decreases and no differences in reproductive success as compared to crosses within population (control). Centaurea solstitialis invasive populations in the Americas generated preponderantly negative fitness interactions, regardless of the pollen source, suggesting selection against immigrants and reinforcement. Other non‐native populations (Australia) as well as individuals from the native range of Spain demonstrated an increase in fitness for between‐region crosses, indicating inbreeding. These differences show an asymmetrical response to inter‐regional gene flow, but no evidence of isolation by distance. 4. Synthesis. The speed of adaptation and the accumulation of reproductive incompatibilities among allopatric populations of invasive species might be more rapid than previously assumed. Our data show a global mosaic of reproductive outputs, showcasing an array of evolutionary processes unfolding during colonization at large biogeographical scales

Experimental admixture among geographically disjunct populations of an invasive plant yields a global mosaic of reproductive incompatibility and heterosis

Invasive species have the ability to rapidly adapt in the new regions where they are introduced. Classic evolutionary theory predicts that the accumulation of genetic differences over time in allopatric isolation may lead to reproductive incompatibilities resulting in decreases in reproductive success and, eventually, to speciation. However, experimental evidence for this theoretical prediction in the context of invasive species is lacking. We aimed to test for the potential of allopatry to determine reproductive success of invasive plants, by experimentally admixing genotypes from six different native and non-native regions of Centaurea solstitialis, an invasive forb for which preliminary studies have detected some degree of reproductive isolation between one native and non-native region. We grew plants under common garden conditions and outcrossed individuals originating from different source populations in the native and introduced range to evaluate reproductive success in terms of seed to ovule ratio produced. We also assessed geographical and genetic isolation among C. solstitialis regions as a potential driving factor of reproductive success. Experimental admixture generated mixed fitness effects, including significant increases, decreases and no differences in reproductive success as compared to crosses within population (control). Centaurea solstitialis invasive populations in the Americas generated preponderantly negative fitness interactions, regardless of the pollen source, suggesting selection against immigrants and reinforcement. Other non-native populations (Australia) as well as individuals from the native range of Spain demonstrated an increase in fitness for between-region crosses, indicating inbreeding. These differences show an asymmetrical response to inter-regional gene flow, but no evidence of isolation by distance. Synthesis. The speed of adaptation and the accumulation of reproductive incompatibilities among allopatric populations of invasive species might be more rapid than previously assumed. Our data show a global mosaic of reproductive outputs, showcasing an array of evolutionary processes unfolding during colonization at large biogeographical scales.Fil: Irimia, Ramona E.. Eberhard Karls Universität Tübingen; Alemania. Universidad de Coimbra; PortugalFil: Hierro, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Branco, Soraia. Universidad de Coimbra; PortugalFil: Sotes, Gastón Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Universidad de Chile; ChileFil: Cavieres, Lohengrin A.. Universidad de Chile; Chile. Universidad de Concepción; ChileFil: Eren, Ozkan. Adnan Menderes Universitesi; TurquíaFil: Lortie, Christopher J.. University of York; Reino UnidoFil: French, Kristine. No especifíca;Fil: Callaway, Ragan M.. University of Montana; Estados UnidosFil: Montesinos, Daniel. Universidad de Coimbra; Portuga

Extensive analysis of native and non-native Centaurea solstitialis L. populations across the world shows no traces of polyploidization

Centaurea solstitialis L. (yellow starthistle, Asteraceae) is a Eurasian native plant introduced as an exotic into North and South America, and Australia, where it is regarded as a noxious invasive. Changes in ploidy level have been found to be responsible for numerous plant biological invasions, as they are involved in trait shifts critical to invasive success, like increased growth rate and biomass, longer life-span, or polycarpy. C. solstitialis had been reported to be diploid (2n = 2x = 16 chromosomes), however, actual data are scarce and sometimes contradictory. We determined for the first time the absolute nuclear DNA content by flow cytometry and estimated ploidy level in 52 natural populations of C. solstitialis across its native and non-native ranges, around the world. All the C. solstitialis populations screened were found to be homogeneously diploid (average 2C value of 1.72 pg, SD = ±0.06 pg), with no significant variation in DNA content between invasive and non-invasive genotypes. We did not find any meaningful difference among the extensive number of native and non-native C. solstitialis populations sampled around the globe, indicating that the species invasive success is not due to changes in genome size or ploidy level

Espécies invasoras - abordagens ecológicas e genômicas para compreender a adaptação local e os estágios iniciais da especiação alopátrica

Tese de Doutoramento em Biociência, especialização em Ecologia, apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraInvasive species are a threat to biodiversity and economy, and extremely challenging to eradicate once established. Much research in invasion ecology had focused on understanding the factors behind invaders’ success in new environments relative to the native range, formulate invasion theories, predict species abundance and occurrence, and provide management solutions. Nowadays, the new advancements in genomic tools and sequencing technologies make possible to disentangle some of the underlying evolutionary processes of trait divergence and rapid adaptation characterizing species introduction and invasion in new habitats. The aim of this thesis was to explore the ecological and genomic basis of rapid adaptation and evolution in the invasive annual forb Centaurea solstitialis (yellow star-thistle), across its worldwide distribution, including sites in the native range (Turkey and Spain) and introduced range (Argentina, Chile, USA and Australia). The thesis focuses on four main directions: i) assessing the role of polyploidy and genome size on species success; ii) testing the allelopathic potential of leaf leachates iii) screening for reproductive isolation in allopatric populations, and iv) evaluating the adaptive phenotypic and genomic potential of introduced populations. In the introduction, I developed a brief systematic review by compiling information on the studies published in Centaurea solstitialis and indexed in the Web of Science during the past 70 years, to assess the current state of knowledge in this species. I identified a number of 365 relevant papers mostly with an ecological focus and having USA as the geographical region of the study. In the first chapter, I used flow cytometry to test the hypothesis that variation in genome size and changes in ploidy levels promote C. solstitialis invasion in the introduced range. I found no shifts in cytotype and similar genome size across native and non-native ranges, excluding the contribution of these factors to species invasiveness. Chapter II explored biogeographical variation in leaf allelochemical production and its effects on phytometer species between the two ranges, using three different leaf extract concentrations (0.25%, 0.5% and 0.75%) and germination bioassays tests. I found that C. solstitialis leaf leachates can have alellopathic potential, exhibiting substantial variation in chemical composition and inhibitory effects across regions. Results suggest that different selection pressures can act on the biochemical profiles in different regions. Chapter III utilized a novel approach in this study system by experimentally producing F1 hybrids of within-region and inter-region crosses to test for reproductive isolation. Results revealed a global mosaic of reproductive incompatibilities and fertilities with asymmetrical responses to inter-continental gene flow. Most negative and strong fitness interactions occurred in the Americas suggesting local adaptation and reinforcement against foreign pollen. In contrast, native Spain showed a preference for non-native pollen resulting in boosts in fertility. Results from this study show that reproductive isolation can emerge relatively fast in allopatry. The final chapter of my thesis explored the role of natural selection in species evolution in the introduced range by measuring neutral genetic differentiation (FST) at thousands of genome wide single nucleotide polymorphisms (SNPs) markers and comparing it with phenotypic differentiation (PST), in a common garden experiment. I also screened for SNPs under selection and performed gene annotation. Based on these data, introduced populations in California, USA had significantly higher PST for seed mass than FST, compared to the two native regions as well as non-native Chile, suggesting that increased seed size had evolved post-introduction in California. Moreover, phenotypic divergence in flowering time and spine length exceeded neutral expectation in the comparison between California and Australia. My research also shed light on the genes likely to be involved in invasiveness, revealing genes associated to regulatory processes and response to environmental stressors. This suggests local adaptation in introduced populations, and reveals the importance of traits related to reproduction and possibly of epigenetic factors in shaping C. solstitialis evolution. Taken together, the results of my PhD thesis have demonstrated the crucial aspect of incorporating biogeography in studying biological invasions, in order to capture variability in factors and processes important for species success in different regions, and pioneers the use of experimental inter-regional crosses to illustrate how gene flow and local adaptation interact across large geographical scales.As espécies invasoras são uma ameaça para a biodiversidade e a economia, sendo extremamente complicado erradicá-las uma vez estabelecidas. A maioria da investigação em ecologia da invasão focou-se em perceber os fatores inerentes ao sucesso das espécies invasoras em novos habitats em comparação com a área nativa, em formular teorias sobre a invasão, em prever a abundância e ocorrência de espécies, e em providenciar soluções de gestão. Hoje em dia, os avanços em ferramentas de genómica e em tecnologias de sequenciação tornam possível desvendar alguns dos processos evolutivos inerentes à divergência de características assim como perceber a adaptação rápida que caracteriza a introdução de espécies e a invasão de novos habitats. Os objetivos desta tese foram explorar a base ecológica e genómica da adaptação rápida e evolução na espécie invasora anual Centaurea solstitialis (cardo-estrelado amarelo), ao longo da sua distribuição à escala global, incluindo populações das áreas nativa (Turquia e Espanha) e invadidas (Argentina, Chile, EUA e Austrália). A tese foca-se em quatro direções principais: i) avaliação do papel da poliploidia e tamanho de genoma no sucesso da espécie; ii) teste do potencial alelopático de lixiviados foliares; iii) avaliação do isolamento reprodutivo em populações alopátricas; e iv) avaliação da potencial adaptativo fenotípico e genómico das populações introduzidas. Na introdução, desenvolvi uma breve revisão sistemática através da compilação de informação sobre os estudos publicados em Centaurea solstitialis e indexados na “Web of Science” durante os últimos 70 anos, para avaliar o estado atual do conhecimento nesta espécie. Identifiquei 365 artigos relevantes com um foco ecológico e tendo os EUA como área geográfica de estudo. No primeiro capítulo, utilizei a citometria de fluxo para testar a hipótese que a variação no tamanho do genoma e alterações nos níveis de ploidia promovem a invasão de C. solstitialis na área onde foi introduzida. Não foram encontradas alterações no citotipo, enquanto que o tamanho do genoma foi semelhante ao longo das áreas nativas e não nativas, excluindo a possibilidade destes fatores contribuírem para a invasão da espécie. No capítulo II explorei a variação biogeográfica na produção aleloquímica das folhas e os seus efeitos nas espécies fitométricas entre as duas áreas, usando três concentrações diferentes de extrato foliar (0,25%, 0,5% e 0,75%) e testes de bioensaios de germinação. Descobri que lixiviados foliares de C. solstitialis podem ter potencial alelopático, exibindo variação substancial na composição química e efeitos inibitórios em todas as regiões. Os resultados sugerem que diferentes pressões seletivas podem atuar nos perfis bioquímicos nas diferentes regiões. No capítulo III utilizei uma nova abordagem neste sistema de estudo, produzindo experimentalmente híbridos F1 de cruzamentos dentro e entre regiões para testar o isolamento reprodutivo. Os resultados revelaram um mosaico global de incompatibilidades e fertilidades reprodutivas com respostas assimétricas ao fluxo génico intercontinental. A maioria das interações de fitness negativas ocorreram nas Américas, sugerindo adaptação local e reforço contra pólen estrangeiro. Por outro lado, a área nativa de Espanha mostrou preferência pelo pólen não nativo, resultando num aumento da fertilidade. Os resultados deste estudo mostram que o isolamento reprodutivo pode emergir relativamente rápido em alopatria. O capítulo final da minha tese explorou o papel da seleção natural na evolução das espécies na área invadida medindo a diferenciação genética neutra (FST) em milhares de marcadores de polimorfismos de nucleotídeo único (SNPs) ao longo de todo o genoma e sua comparação com a diferenciação fenotípica (PST), numa experiência de estufa. Também examinei SNPs sob seleção e realizei anotação de genes. Com base nestes dados, as populações introduzidas na Califórnia, nos EUA, apresentaram PST significativamente maior para o peso das sementes do que o FST, em comparação com as duas regiões nativas e o Chile não nativo, sugerindo que o aumento do tamanho das sementes evoluiu após a introdução na Califórnia. Além disso, a divergência fenotípica no tempo de floração e comprimento dos espinhos excedeu a expectativa neutra na comparação entre a Califórnia e a Austrália. A minha investigação também lançou novos dados sobre os genes que estão provavelmente envolvidos na invasão, revelando genes associados a processos regulatórios e com a resposta a estressores ambientais. Isto sugere adaptação local em populações introduzidas e revela a importância de características relacionadas com reprodução e, possivelmente, fatores epigenéticos relacionados com a evolução de C. solstitialis. Em suma, os resultados da minha tese de doutoramento demonstraram que é crucial a incorporação da biogeografia no estudo de invasões biológicas, a fim de capturar a variabilidade em fatores e processos importantes para o sucesso de espécies em diferentes regiões, e é pioneira no uso de cruzamentos inter-regionais experimentais para ilustrar como o fluxo génico e a adaptação local interagem ao longo de grandes escalas geográficas.POPH/ES

Taxonomic revision of Rochefortia Sw. (Ehretiaceae, Boraginales)

Rochefortia is a small taxon of woody plants in the Ehretiaceae (Boraginales) exhibiting coriaceous leaves with cystoliths, small whitish flowers and drupaceous fruits containing four pyrenes. It shares the dioecious sex distribution with its sister group Lepidocordia and can be delimited from the latter (and all other Ehretiaceae) by the presence of thorns. Neotropical Rochefortia is distributed over most Caribbean islands, Central America and northern South America. Twenty-eight validly published names (corresponding to twenty-one typified taxa at the species level and below) are available in Rochefortia, but the precise number of species to be accepted has been elusive before this revision.In the course of the present revision, 353 herbarium collections, comprising approximately 540 Rochefortia specimens, were entried into a BRAHMS data base providing information about protologues and types and retrospective georeferences if possible. Based on the combination of molecular and morphological data we propose to recognise nine species of Rochefortia, namely R. acanthophora, R. bahamensis, R. barloventensis, R. cubensis, R. cuneata, R. lundellii, R. oblongata, R. spinosa and R. stellata (the remaining nineteen validly published names are synonymised under such names). Morphological description of each species and an identification key are provided