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Premise of the Study We provide the largest phylogenetic analyses to date of Apocynaceae in terms of taxa and molecular data as a framework for analyzing the evolution of vegetative and reproductive traits. Methods We produced maximum‐likelihood phylogenies of Apocynaceae using 21 plastid loci sampled from 1045 species (nearly 25% of the family) and complete plastomes from 73 species. We reconstructed ancestral states and used model comparisons in a likelihood framework to analyze character evolution across Apocynaceae. Key Results We obtained a well‐supported phylogeny of Apocynaceae, resolving poorly understood tribal and subtribal relationships (e.g., among Amsonieae and Hunterieae, within Asclepiadeae), rejecting monophyly of Melodineae and Odontadenieae, and placing previously unsampled and enigmatic taxa (e.g., Pycnobotrya). We provide new insights into the evolution of Apocynaceae, including frequent shifts between herbaceousness and woodiness, reversibility of twining, integrated evolution of the corolla and gynostegium, and ancestral baccate fruits. Conclusions Increased sampling and selection of best‐fitting models of evolution provide more resolved and robust estimates of phylogeny and character evolution than obtained in previous studies. Evolutionary inferences are sensitive to choice of phylogenetic frameworks and models.

Premise of the Study We tested a hypothesis that predicts loss of chemical defenses on island plant populations (LCDIH) as an evolutionary response to limited herbivore pressures. Methods Using a common garden approach, we grew 16 populations (N = 286 seedlings) of Periploca laevigata, a Mediterranean shrub for which previous studies suggested that animal browsing elicits defensive responses mediated by tannins. Our experimental setting represented a wide latitudinal gradient (37–15°N) encompassing three island systems, virtually free of large herbivores, and three mainland areas. Putative chemical defenses were estimated from tannin–protein precipitation assays, and inducible responses in growth and chemical traits were assessed between seasons and by subjecting plants to a pruning treatment. Key Results We failed to find support for the LCDIH, since island populations (Canary Islands, Cape Verde) had increasingly higher constitutive levels of tannins at lower latitudes. Seasonality, but not experimental pruning, induced variation in levels of tannins in a consistent pattern across populations. Thus, net differences in leaf tannin concentration remained similar among geographical areas regardless of the factor considered, with latitude being the best explanatory factor for this trait over seasonal growth patterns. Conclusions Geographical variation in total tannin pools appears to be mediated by factors other than herbivore pressure in P. laevigata. We hypothesize that abiotic correlates of latitude not considered in our study have promoted high constitutive levels of leaf tannins across Macaronesian populations, which ultimately may explain the pattern of seasonal variation and latitudinal increase from Mediterranean to subtropical Cape Verde populations.

This study aimed to evaluate the antioxidant activity and total phenolic content (TPC) and total flavonoid content (TFC) of crude extracts obtained from three Asclepiadaceae species, namely, Calotropis procera L., Peruglaria tomentosa L., and Pentatropis spiralis (Forsk.) Decne. Both butanol and aq. methanol extracts of the three species showed the highest amount of phenol and flavonoid contents, which exhibited the greatest antioxidant activity in the scavenging of 2,2-diphenyl-2-picrylhydrazyl free radical (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation (ABTS), ferrous chelating effect (FIC), and hydroxyl radical (HDR) assays. Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, sponins, flavonoids, terpenoids, and glycosides. LC-MS analysis was carried out to identify the major compounds from each crude extract. A total of 12 phenolic compounds in the extracts of the 3 species were identified and quantified, including 9 flavonoids, 2 hydroxybenzoic acids, and 3 hydroxycinnamic acids. The current study also revealed a good correlation between total phenolic contents and the observed antioxidant activity of the crude extracts.

Abstract Hancornia speciosa (Apocynaceae) trees are valuable for several communities that survive from collecting their fruits. However, H. speciosa is threatened due to the increasing deforestation in the Brazilian Cerrado. This study aimed to identify the loss and solution sources, and their importance in terms of loss or income gain on H. speciosa trees applying the Percentage of Importance Indice (% I.I.). The % I.I. separated the loss sources [e.g., sap-sucking Phenacoccus madeirensis on leaves = 46.25%)] on the percentage of reduction of fruit production (e.g., 0.004%), calculated the attention level (e.g., 0.0937/leaf), with a total lost production of 0.02% (≈ 24 total lost fruits). The solution sources spiders, predator thrips Holopothrips sp., and Chrysoperla sp. showed the highest % I.I. on H. speciosa trees, increasing system productivity by 0.01% (≈ 16 total saved fruits). Spiders were the most important predator group, saving 13 fruits (I.G.=0.009%) and the tending ants reduced around 0.19 fruits (I.G.=-0.0003%). The loss sources and ants are not harmful to H. speciosa trees on the natural system - Cerrado, but, in future commercial crops (e.g., monoculture), they can cause significant damages to fruit production. Resumo As árvores de Hancornia speciosa (Apocynaceae) são valiosas para várias comunidades que sobrevivem da coleta de seus frutos. No entanto, H. speciosa está ameaçada devido ao crescente desmatamento no Cerrado brasileiro. Este estudo teve como objetivo identificar as fontes de perda e solução, e sua importância em termos de perda ou ganho de renda em árvores de H. speciosa aplicando a Percentagem de Índice de Importância (% I.I.). O % I.I. separou as fontes de perda [ex.: Phenacoccus madeirensis sugador de seiva nas folhas = 46,25%)] na porcentagem de redução da produção de frutos (ex.: 0,004%), calculou o nível de atenção (ex.: 0,0937/folha), com uma produção total perdida de 0,02% (≈ 24 frutos perdidos no total). As fontes de solução aranhas, tripes predadores Holopothrips sp. e Chrysoperla sp. apresentaram os maiores % I.I. em árvores de H. speciosa, aumentando a produtividade do sistema em 0,01% (≈ 16 frutos totais salvos). As aranhas foram o grupo predador mais importante, salvando 13 frutos (I.G.=0,009%) e as formigas cuidadoras reduziram cerca de 0,19 frutos (I.G.=-0,0003%). As fontes de perda e formigas não são prejudiciais às árvores de H. speciosa no sistema natural - Cerrado, mas, em futuras culturas comerciais (ex.: monocultura), podem causar danos significativos à produção de frutos.

Apocynaceae and Orchidaceae are two angiosperm families with extreme flower synorganization. They are unrelated, the former in eudicots, the latter in monocots, but they converge in the formation of pollinia and pollinaria, which do not occur in any other angiosperm family, and for which extreme synorganization of floral organs is a precondition. In each family extensive studies on flower development and evolution have been performed; however, newer comparative studies focusing on flower synorganization and involving both families together are lacking. For this study an extensive search through the morphological literature has been conducted. Based on this and my own studies on flowers in various Apocynaceae and Orchidaceae and complex flowers in other angiosperms with scanning electron microscopy and with microtome section series, a review on convergent floral traits in flower development and architecture in the two families is presented. There is a tendency of protracted development of synorganized parts in Apocynaceae and Orchidaceae (development of synorganization of two or more organs begins earlier the more accentuated it is at anthesis). Synorganization (or complexity) also paves the way for novel structures. One of the most conspicuous such novel structures in Apocynaceae is the corona, which is not the product of synorganization of existing organs; however, it is probably enhanced by synorganization of other, existing, floral parts. In contrast to synorganized parts, the corona appears developmentally late. Synorganization of floral organs may lead to a large number of convergences in clades that are only very distantly related. The convergences that have been highlighted in this comparative study should be developmentally investigated directly in parallel in future studies.

Belonging to the Brazilian flora, the species Hancornia speciosa (Gomes), known as mangabeira, has bioactive compounds of interest, such as flavonoids, xanthones, and proanthocyanidins. The objective of this study was to determine how the supplementation of sugars in culture medium affects the osmotic potential of the medium, as well as its influence on cell growth and on the concentration of phenolic compounds. For this purpose, after 90 days of subculture, 20 mL aliquots of the cultures were added to flasks containing 20 mL of medium with different sugars (glucose, fructose, sucrose, mannitol, and sorbitol) under a 16-h photoperiod with a spectral range between 400 and 700 nm of photosynthetically active radiation (45–55 μmol m −2  s −1 ) in a shaker at 110 rpm. After 30 days, the pH, electrical conductivity, osmotic potential, biomass accumulation, and concentrations of phenolic compounds were evaluated. Regardless of their concentration in the medium, the sugars sorbitol and mannitol provided more unfavorable conditions for water absorption at the cellular level, reducing the water potential of the medium. Sucrose favored greater water absorption and biomass accumulation. Among the various sugar concentrations, 3% (30 g/L) sucrose or glucose improved the accumulation of fresh and dry cell weight and the production of polyphenols such as chlorogenic acid, epicatechin, rosmarinic acid, hesperidin, rutin, and quercetin. In addition, they resulted in a higher osmotic potential of the medium and larger cells than other carbon sources. Despite the differences in cell size, no culture conditions compromised cell survival.

Despite sequestration of toxins being a common coevolutionary response to plant defence in phytophagous insects, the macroevolution of the traits involved is largely unaddressed. Using a phylogenetic approach comprising species from four continents, we analysed the ability to sequester toxic cardenolides in the hemipteran subfamily Lygaeinae, which is widely associated with cardenolide-producing Apocynaceae. In addition, we analysed cardenolide resistance of their Na⁺/K⁺-ATPases, the molecular target of cardenolides. Our data indicate that cardenolide sequestration and cardenolide-resistant Na⁺/K⁺-ATPase are basal adaptations in the Lygaeinae. In two species that shifted to non-apocynaceous hosts, the ability to sequester was secondarily reduced, yet Na⁺/K⁺-ATPase resistance was maintained. We suggest that both traits evolved together and represent major coevolutionary adaptations responsible for the evolutionary success of lygaeine bugs. Moreover, specialization on cardenolides was not an evolutionary dead end, but enabled this insect lineage to host shift to cardenolide-producing plants from distantly related families.

The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy.

Plant-soil feedback is recognized as the mutual interaction between plants and soil microorganisms, but its role on the biological invasion of the Brazilian tropical seasonal dry forest by invasive plants still remains unclear. Here, we analyzed and compared the arbuscular mycorrhizal fungi (AMF) communities and soil characteristics from the root zone of invasive and native plants, and tested how these AMF communities affect the development of four invasive plant species (Cryptostegia madagascariensis, Parkinsonia aculeata, Prosopis juliflora, and Sesbania virgata). Our field sampling revealed that AMF diversity and frequency of the Order Diversisporales were positively correlated with the root zone of the native plants, whereas AMF dominance and frequency of the Order Glomerales were positively correlated with the root zone of invasive plants. We grew the invasive plants in soil inoculated with AMF species from the root zone of invasive (I changed) and native (I unaltered) plant species. We also performed a third treatment with sterilized soil inoculum (control). We examined the effects of these three AMF inoculums on plant dry biomass, root colonization, plant phosphorous concentration, and plant responsiveness to mycorrhizas. We found that I unaltered and I changed promoted the growth of all invasive plants and led to a higher plant dry biomass, mycorrhizal colonization, and P uptake than control, but I changed showed better results on these variables than I unaltered. For plant responsiveness to mycorrhizas and fungal inoculum effect on plant P concentration, we found positive feedback between changed-AMF community (I changed) and three of the studied invasive plants: C. madagascariensis, P. aculeata, and S. virgata.

Decalepis arayalpathra, a critically endangered plant species, has a restricted and fragmented population in Southern Western Ghats, India. This study is a first attempt to evaluate genetic diversity and population structure in the nine wild populations of D. arayalpathra based on molecular pattern realized through the marker assays. Principal coordinate analysis (PCoA) and Nei’s unweighted pair-group method with arithmetic average (UPGMA)-based hierarchical clustering of both the marker assays suggest strong genetic clustering between the individuals corresponding to their geographical ranges. Mantel test also corroborates a close genetic proximity between genetic and geographic data (r = 0.389). Population genetic analysis revealed low levels of gene flow [inter-simple sequence repeat (ISSR) = 0.289 and random amplified polymorphic DNA (RAPD) = 0.847] between the populations, in line with high genetic differentiation (Gst = 0.531 with ISSR and 0.440 with RAPD), which was also supported by analysis of molecular variance (AMOVA), that 54 % (ISSR) and 64 % (RAPD) total variation resided within populations. Bayesian model-based STRUCTURE analysis detected three genetic clusters showing the high degree of admixture within population. Based on the findings, such as inbreeding depression and the loss of genetic diversity, suggestions for conservation strategies are provided to preserve the genetic resources of this endangered species.