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1.
Am J Bot ; 108(5): 828-843, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-34019302

RESUMEN

PREMISE: There is little direct evidence linking floral development and pollination biology in plants. We characterize both aspects in plain and ornamented flowers of Trimezieae (Iridaceae) to investigate how changes in floral ontogeny may affect their interactions with pollinators through time. METHODS: We examined floral ontogeny in 11 species and documented pollination biology in five species displaying a wide range of floral morphologies. We coded and reconstructed ancestral states of flower types over the tribal phylogeny to estimate the frequency of transition between different floral types. RESULTS: All Trimezieae flowers are similar in early floral development, but ornamented flowers have additional ontogenetic steps compared with plain flowers, indicating heterochrony. Ornamented flowers have a hinge pollination mechanism (newly described here) and attract more pollinator guilds, while plain flowers offer less variety of resources for a shorter time. Although the ornamented condition is plesiomorphic in this clade, shifts to plain flowers have occurred frequently and abruptly during the past 5 million years, with some subsequent reversals. CONCLUSIONS: Heterochrony has resulted in labile morphological changes during flower evolution in Trimezieae. Counterintuitively, species with plain flowers, which are endemic to the campo rupestre, are derived within the tribe and show a higher specialization than the ornamented species, with the former being visited by pollen-collecting bees only.


Asunto(s)
Iridaceae , Polinización , Animales , Abejas , Biología , Flores , Polen
2.
Mol Phylogenet Evol ; 161: 107163, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33831546

RESUMEN

Atlantic Forest Inselbergs (AFI) and Campos Rupestres (CR) are mountains and highlands of eastern South America, relatively poorly studied and highly threatened, which display extraordinary levels of plant endemism and richness. In spite of their geographical and environmental differences, the origin of the flora of CR and AFI are likely linked to each other, because several plant clades are distributed across both ecosystems. In addition to these studies, little has been investigated about the historical biogeographical connections between AFI and CR and most evolutionary studies are restricted to CR. Barbacenia (Velloziaceae) is widely spread and nearly endemic to the AFI and CR outcrops and thus represent an ideal system to study the biogeographical connections between CR and AFI. Besides, given the remarkable diversity of Barbacenia in CR compared to AFI, it appears that different factors were important drivers in the diversification of Barbacenia lineages, likely leading to different patterns of morphological diversification. Here, we integrate phylogenetic, biogeographic and morphological approaches to: (i) address whether AFI species of Barbacenia are monophyletic and thus a single colonization of AFI can be inferred; (ii) understand the timing and geographical origin of CR and AFI clades; (iii) compare morphological diversity between Barbacenia from AFI and CR under the hypothesis that these two systems have experienced similar levels of morphological diversification during their evolutionary history. To this end, we presented a phylogeny inferred using plastid (atpB-rbcL, trnH-psbA and trnL-trnF) and nuclear (ITS) markers and a complete sampling of AFI Barbacenia, estimated divergence times, reconstructed the ancestral areas of Barbacenia clades and compared their morphological diversity based on a dataset of 16 characters. Our results provided evidence for a diversification of Barbacenia from the Middle Miocene to Pleistocene, as suggested in previous studies. We suggest that stepping-stone dispersal across mountaintops in interplay with paleovegetation dynamics during the global Miocene cooling and Pleistocene climatic oscillations may played an important role in the range expansion of modern AFI Barbacenia lineages. Finally, our results also showed a significant differences in morphological diversity between AFI and CR clades, suggesting a long-term morphological stasis in AFI species.


Asunto(s)
Evolución Biológica , Ecosistema , Magnoliopsida/anatomía & histología , Magnoliopsida/clasificación , Filogenia , Filogeografía
3.
Biodivers Data J ; 8: e53135, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32617070

RESUMEN

BACKGROUND: Isolated monoliths of granitic and/or gneissic rock rising abruptly from the surrounding landscape are known as inselbergs. Dome-shaped inselbergs are common throughout the Atlantic Forest in south-eastern Brazil, a region known as Sugarloaf Land (SLL). This study aimed to create the first checklist of vascular plant species occurring on lowland inselbergs in SLL, with a focus on vegetation islands. We used information from online databases, our own field sampling and data from previously-published studies. We found 548 vascular plant species (505 angiosperms; 43 ferns and lycophytes) belonging to 69 families and 212 genera. Of all identified species, 536 are native and 12 are naturalised. NEW INFORMATION: We updated the information currently available in Flora do Brasil 2020, as 59% of the angiosperms and 63% of the ferns and lycophytes on our checklist were not previously characterised as occurring on rock outcrops. As a first step towards generating a Virtual Herbarium of lowland inselberg vascular plants, we added barcode vouchers with images available online for 75% of the total number of vascular species. In the official lists of endangered species, 115 angiosperms and five ferns and lycophytes are mentioned. However, the conservation status of many species have not yet been evaluated (77% angiosperms; 88% ferns and lycophytes), thus this list is an important step towards their conservation. The information provided herein is essential for management programmes related to rock outcrops in Brazil as they are facing serious threats to conservation.

4.
Ann Bot ; 122(1): 165-180, 2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-29800276

RESUMEN

Background and Aims: The greater diversity of plant clades in the Neotropics compared to their relatives in Africa is a pervasive pattern in biogeography. To better understand the causes of this imbalance, we studied the diversification dynamics of the monocot family Velloziaceae. In addition to being conspicuously richer in the Neotropics compared to the Palaeotropics, many species of Velloziaceae exhibit extreme desiccation tolerance (i.e. 'resurrection' behaviour), and other ecological specializations to life on rocky outcrops, poor sandy soils, open vegetation and seasonally dry climates. Velloziaceae is also ecologically dominant in the campos rupestres, a habitat having exceptionally high plant diversity and endemism in Brazil. Methods: We reconstructed a densely sampled time-calibrated molecular phylogeny and used state-dependent and state-independent models to estimate rates of lineage diversification in relation to continent-scale geographical occurrence and functional traits associated with desiccation tolerance and water storage capacity. Key Results: Independent shifts to faster diversification occurred within two Neotropical lineages, Vellozia and Barbacenia. The Vellozia radiation was associated with the presence of conspicuous aerial stems, and was followed by decreasing diversification rates during the Oligocene, a time of rising global temperatures and expanding open areas around the world. The Barbacenia radiation was faster and more recent, occurring during the cooling conditions of the Miocene, and associated with the acquisition of aquiferous parenchyma on the leaves. Conclusions: High species richness of Velloziaceae in South America has been driven by faster diversification in lineages predominantly occurring in the campos rupestres, putatively by the evolution of adaptive strategies in response to independent climatic events. The radiation of Vellozia in particular might have played a key role in the assembly of the campos rupestres vegetation.


Asunto(s)
Biodiversidad , Magnoliopsida/genética , Adaptación Fisiológica , Evolución Biológica , Brasil , Desecación , Ecosistema , Magnoliopsida/fisiología , Magnoliopsida/efectos de la radiación , Fenotipo , Filogenia , Tallos de la Planta/genética , Tallos de la Planta/fisiología , Tallos de la Planta/efectos de la radiación
5.
Proc Natl Acad Sci U S A ; 114(40): 10695-10700, 2017 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-28923966

RESUMEN

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.


Asunto(s)
Biodiversidad , Bases de Datos Factuales , Plantas/clasificación , Bosque Lluvioso , Brasil
6.
Bol. latinoam. Caribe plantas med. aromát ; 15(4): 215-232, jul. 2016. tab
Artículo en Inglés | LILACS | ID: biblio-907539

RESUMEN

To investigate potential sources of novel grain protector compounds against Sitophilus zeamais (Coleoptera: Curculionidae), which is an important insect pest of stored cereals, this study evaluated the bioactivity of ethanolic extracts (66) prepared from 29 species belonging to 11 different genera of Neotropical Annonaceae. A screening assay demonstrated that the most pronounced bioactive effects on S. zeamais were caused by ethanolic extracts from Annona montana, A. mucosa, A. muricata, and A. sylvatica seeds, causing the death of all weevils exposed, almost complete inhibition of the F1 progeny and a drastic reduction in grain losses. Furthermore, the ethanolic extracts obtained from the leaves of A. montana, A. mucosa, A. muricata, and Duguetia lanceolata, especially A. montana and A. mucosa, demonstrated significant bioactive effects on the studied variables; however, the activity levels were less pronounced than in the seed extracts, and the response was dependent on the concentration used. This study is the first to report the activity of secondary metabolites from D. lanceolata on insects as well as the action of A. sylvatica on pests associated with stored grains.


Para investigar las posibles fuentes de nuevos compuestos protectores de granos contra Sitophilus zeamais (Coleoptera: Curculionidae), una importante plaga de los cereales almacenados, este estudio evaluó la bioactividad de los extractos etanólicos (66) preparados a partir de 29 especies pertenecientes a 11 géneros distintos de Anonaceas Neotropicales. Un ensayo de selección demostró que los efectos bioactivos más relevantes sobre S. zeamais fueron causados por los extractos etanólicos de las semillas de Annona montana, de A. mucosa, de A. muricata y de A. sylvatica, que causaron la muerte de todos los gorgojos expuestos, la inhibición parcial de la progenie F1 y una drástica reducción de las pérdidas de grano. Además, los extractos etanólicos obtenidos de las hojas de A. montana, de A. mucosa, de A. muricata y de Duguetia lanceolata, especialmente de A. montana y de A. mucosa, demostraron efectos bioactivos significativos sobre las variables estudiadas. Sin embargo, los niveles de bioactividad fueron menores en comparación con los extractos de semillas, y la respuesta fue dependiente de la concentración utilizada. Este estudio es el primer relato sobre la actividad de los metabolitos secundarios de D. lanceolata sobre insectos, así como la acción de A. sylvatica sobre plagas asociadas a los granos almacenados.


Asunto(s)
Animales , Annonaceae/química , Repelentes de Insectos/análisis , Insecticidas/análisis , Extractos Vegetales/química , Gorgojos , Grano Comestible , Almacenamiento de Alimentos , Control de Insectos
7.
Nat Prod Commun ; 7(10): 1365-7, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23157012

RESUMEN

The volatile and non-volatile constituents of the unripe fruits of Magnolia ovata (A. St.-Hil.) Spreng. (Magnoliaceae) were studied. The essential oils were obtained by hydrodistillation of the fruit of two plant populations (A and B) and analyzed by GC/FID and GC/MS. The oil of sample A was rich in sesquiterpenes, mainly spathulenol (19.3%), while the oil of sample B showed a predominance of aliphatic compounds, mainly hexadecanoic acid (52.0%). Extracts of the dried fruit contained fourteen known compounds including nine lignoids (magnovatin A, magnovatin B, acuminatin, licarin A, oleiferin A, oleiferin C, kadsurenin M, 4-O-demethylkadsurenim M and 7-epi-virolin), two sesquiterpene lactones (parthenolide and michelenolide) and three alkaloids (lysicamine, lanuginosine and O-methylmoschatoline). Michelenolide, 7-epi-virolin and lisycamine are reported for the first time in the species, while the remaining compounds have already been reported in the leaves and/or trunk bark o f Magnolia ovata. Acetylation o f oleiferin A yielded a ne wcompound, acetyl oleiferin A, whose NMR data and that of michelenolide are furnished.


Asunto(s)
Frutas/química , Magnolia/química , Aceites Volátiles/química , Alcaloides/química , Cromatografía de Gases y Espectrometría de Masas , Lactonas/química , Espectroscopía de Resonancia Magnética , Sesquiterpenos/química
8.
Am J Bot ; 99(9): 1477-88, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22889618

RESUMEN

PREMISE OF THE STUDY: Vellozia hirsuta forms a complex presenting wide morphological and anatomical variation, resulting in five specific names and 14 morpho-anatomical patterns occurring in disjunct populations. We carried out a phylogeographical study to investigate the existence of correlation among the genetic and morphological patterns within this complex, and to determine whether it is composed of various species or should be treated as an ochlospecies, a species having widely polymorphic and weakly polytypic complex variation, with morphological characteristics varying independently. METHODS: We carried out phylogeographical analyses using cpDNA rpl32F-trnL intergenic region. KEY RESULTS: We found 20 haplotypes in 23 populations sampled. The populations are genetically structured (Φ(ST) = 0.818) into four phylogeographical groups demonstrating geographical structuring but with no correlation with morpho-anatomical patterns. Our analyses do not support recognizing any of the species now synonymized under Vellozia hirsuta. The northern populations were the most genetically differentiated and could be considered a distinct taxon, as they are also morphologically different. CONCLUSIONS: It is recommended that Vellozia hirsuta be considered a single enormously variable species. The patterns of variation within V. hirsuta probably are related to climatic changes that occurred during the Pleistocene Epoch in tropical Brazil when reductions in forest cover favored the expansion of V. hirsuta populations into extensive lowland areas. The expansion of forest cover at the end of the glaciations would have again restricted the occurrence of campos rupestres vegetation to high elevations, which constitute the current centers of diversity of this species.


Asunto(s)
Geografía , Magnoliopsida/anatomía & histología , Magnoliopsida/genética , Teorema de Bayes , Análisis por Conglomerados , ADN de Cloroplastos/genética , ADN Intergénico/genética , Variación Genética , Genética de Población , Haplotipos/genética , Fenotipo , Filogenia
9.
Ann Bot ; 110(3): 689-702, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22711695

RESUMEN

BACKGROUND AND AIMS: The Neotropical tribe Trimezieae are taxonomically difficult. They are generally characterized by the absence of the features used to delimit their sister group Tigridieae. Delimiting the four genera that make up Trimezieae is also problematic. Previous family-level phylogenetic analyses have not examined the monophyly of the tribe or relationships within it. Reconstructing the phylogeny of Trimezieae will allow us to evaluate the status of the tribe and genera and to examine the suitability of characters traditionally used in their taxonomy. METHODS: Maximum parsimony and Bayesian phylogenetic analyses are presented for 37 species representing all four genera of Trimezieae. Analyses were based on nrITS sequences and a combined plastid dataset. Ancestral character state reconstructions were used to investigate the evolution of ten morphological characters previously considered taxonomically useful. KEY RESULTS: Analyses of nrITS and plastid datasets strongly support the monophyly of Trimezieae and recover four principal clades with varying levels of support; these clades do not correspond to the currently recognized genera. Relationships within the four clades are not consistently resolved, although the conflicting resolutions are not strongly supported in individual analyses. Ancestral character state reconstructions suggest considerable homoplasy, especially in the floral characters used to delimit Pseudotrimezia. CONCLUSIONS: The results strongly support recognition of Trimezieae as a tribe but suggest that both generic- and species-level taxonomy need revision. Further molecular analyses, with increased sampling of taxa and markers, are needed to support any revision. Such analyses will help determine the causes of discordance between the plastid and nuclear data and provide a framework for identifying potential morphological synapomorphies for infra-tribal groups. The results also suggest Trimezieae provide a promising model for evolutionary research.


Asunto(s)
Núcleo Celular/genética , Flores/anatomía & histología , Iridaceae/clasificación , Iridaceae/genética , Hojas de la Planta/anatomía & histología , Plastidios/genética , Teorema de Bayes , ADN de Plantas , Evolución Molecular , Iridaceae/anatomía & histología , Filogenia , Análisis de Secuencia de ADN
10.
Ann Bot ; 108(1): 87-102, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21693665

RESUMEN

BACKGROUND AND AIMS: The amount of data collected previously for Velloziaceae neither clarified relationships within the family nor helped determine an appropriate classification, which has led to huge discordance among treatment by different authors. To achieve an acceptable phylogenetic result and understand the evolution and roles of characters in supporting groups, a total evidence analysis was developed which included approx. 20 % of the species and all recognized genera and sections of Velloziaceae, plus outgroups representatives of related families within Pandanales. METHODS: Analyses were undertaken with 48 species of Velloziaceae, representing all ten genera, with DNA sequences from the atpB-rbcL spacer, trnL-trnF spacer, trnL intron, trnH-psbA spacer, ITS ribosomal DNA spacers and morphology. KEY RESULTS: Four groups consistently emerge from the analyses. Persistent leaves, two phloem strands, stem cortex divided in three regions and violet tepals support Acanthochlamys as sister to Velloziaceae s.s., which are supported mainly by leaves with marginal bundles, transfusion tracheids and inflorescence without axis. Within Velloziaceae s.s., an African Xerophyta + Talbotia clade is uniquely supported by basal loculicidal capsules; an American clade, Barbacenia s.l. + Barbaceniopsis + Nanuza + Vellozia, is supported by only homoplastic characters. Barbacenia s.l. (= Aylthonia + Barbacenia + Burlemarxia + Pleurostima) is supported by a double sheath in leaf vascular bundles and a corona; Barbaceniopsis + Nanuza + Vellozia is not supported by an unambiguous character, but Barbaceniopsis is supported by five characters, including diclinous flowers, Nanuza + Vellozia is supported mainly by horizontal stigma lobes and stem inner cortex cells with secondary walls, and Vellozia alone is supported mainly by pollen in tetrads. CONCLUSIONS: The results imply recognition of five genera (Acanthochlamys (Xerophyta (Barbacenia (Barbaceniopsis, Vellozia)))), solving the long-standing controversies among recent classifications of the family. They also suggest a Gondwanan origin for Velloziaceae, with a vicariant pattern of distribution.


Asunto(s)
Evolución Biológica , Magnoliopsida/clasificación , Filogenia , África , Secuencia de Bases , ADN de Plantas/genética , Evolución Molecular , Magnoliopsida/anatomía & histología , Magnoliopsida/genética , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , América del Sur
11.
J Nat Prod ; 72(8): 1529-32, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19658431

RESUMEN

Two new lignans, magnovatins A (1) and B (2), along with nine known compounds, were isolated from the leaves of Magnolia ovata. The known compounds were identified as acuminatin (3), licarin A (4), kadsurenin M, 4-O-demethylkadsurenin M, oleiferin A, oleiferin C, spathulenol, parthenolide, and 11,13-dehydrocompressanolide. In addition, compounds 1 and 2 yielded four new derivatives (1a, 1b, 2a, and 2b). The structures of the new compounds were established on the basis of spectrometric data evaluation. Free-radical scavenging and antimicrobial activities of the major compunds 1, 3, and 4 were investigated.


Asunto(s)
Antibacterianos/aislamiento & purificación , Depuradores de Radicales Libres/aislamiento & purificación , Magnolia/química , Plantas Medicinales/química , Antibacterianos/química , Antibacterianos/farmacología , Brasil , Escherichia coli/efectos de los fármacos , Flavonoides/aislamiento & purificación , Flavonoides/farmacología , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Glicósidos/aislamiento & purificación , Glicósidos/farmacología , Lignanos/aislamiento & purificación , Lignanos/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Hojas de la Planta/química , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Levaduras/efectos de los fármacos
12.
J Ethnopharmacol ; 124(3): 369-76, 2009 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-19524658

RESUMEN

AIM OF THE STUDY: Magnolia ovata (A.St.-Hil.) Spreng (formerly Talauma ovata), known as "pinha-do-brejo" or "baguaçu", is a large tree widely distributed in Brazil. Its trunk bark has been used in folk medicine against fever. However, no data have been published to support the antipyretic ethnopharmacological use. This study investigated the antipyretic and anti-inflammatory effects of the ethanolic extract (EEMO), dichloromethane fraction (DCM), and the isolated compound costunolide. MATERIALS AND METHODS: The antipyretic and anti-inflammatory activities were evaluated in experimental models of fever and inflammation in mice. RESULTS: The oral administration of EEMO, DCM and costunolide inhibited carrageenan (Cg)-induced paw oedema (ID(50) 72.35 (38.64-135.46) mg/kg, 5.8 (2.41-14.04) mg/kg and 0.18 (0.12-0.27) mg/kg, respectively) and was effective in abolishing lipopolysaccharide (LPS)-induced fever (30 mg/kg, 4.5 mg/kg and 0.15 mg/kg, respectively). EEMO was also effective in reducing cell migration in the pleurisy model. Intraplantar injection of costunolide also reduced the paw oedema, myeloperoxidase and N-acetyl-glucosaminidase activity induced by Cg in mice. CONCLUSIONS: Collectively, these results show, for the first time, that extracts obtained from Magnolia ovata possess antipyretic and anti-inflammatory properties, and costunolide appears to be the compound responsible for these effects.


Asunto(s)
Analgésicos no Narcóticos/farmacología , Antiinflamatorios no Esteroideos/farmacología , Magnolia/química , Sesquiterpenos/farmacología , Acetilglucosaminidasa/metabolismo , Animales , Carragenina , Movimiento Celular/efectos de los fármacos , Edema/inducido químicamente , Edema/prevención & control , Etanol , Exudados y Transudados/metabolismo , Fiebre/inducido químicamente , Fiebre/prevención & control , Indicadores y Reactivos , Leucocitos/efectos de los fármacos , Lipopolisacáridos , Masculino , Cloruro de Metileno , Ratones , Peroxidasa/metabolismo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Cavidad Pleural/citología , Sesquiterpenos/química , Solventes
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