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1.
Am J Bot ; 110(6): e16199, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37318759

RESUMO

PREMISE: Many tropical plants are bat-pollinated, but these mammals often carry copious, multispecific pollen loads making bat-pollinated plants susceptible to heterospecific pollen deposition and reproductive interference. We investigated pollen transfer between sympatric bat-pollinated Burmeistera species and their response to heterospecific pollen deposition from each other. METHODS: We quantified conspecific and heterospecific pollen deposition for two populations of B. ceratocarpa, a recipient species in heterospecific pollen transfer interactions, that co-occur with different donor relatives (B. borjensis and B. glabrata). We then used a cross-pollination scheme using pollen mixtures to assess the species' responses to heterospecific pollen deposition in terms of fruit abortion and seed production. RESULTS: Burmeistera ceratocarpa received significantly more heterospecific pollen from its relatives at both sites than its own pollen was deposited on its relatives. However, heterospecific pollen deposition only affected seed production by B. borjensis and B. glabrata, but not by B. ceratocarpa, suggesting that early acting post-pollination barriers buffer the latter against reproductive interference. Crosses between sympatric and allopatric populations suggest that the study species are fully isolated in sympatry, while isolation between allopatric populations is strong but incomplete. CONCLUSIONS: We did not observe evidence of reproductive interference among our study species, because either heterospecific pollen deposition did not affect their seed production (B. ceratocarpa) or they receive heterospecific pollen only rarely (B. borjensis and B. glabrata). Frequent heterospecific pollen deposition might favor the evolution of barriers against foreign pollen (as in B. ceratocarpa) that alleviate the competitive costs of sharing low fidelity pollinators with co-occurring species.


Assuntos
Campanulaceae , Quirópteros , Animais , Quirópteros/fisiologia , Flores/fisiologia , Reprodução/fisiologia , Polinização/fisiologia , Pólen/fisiologia
2.
Biodivers Data J ; 11: e99603, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38327360

RESUMO

Background: Knowledge of Carex L. (true sedges) and Hypericum L. (St. John's wort) in the Neotropics is fragmentary. New information: As a result of a fieldwork campaign in Ecuador and revision of herbarium collections (K, QCA and QCNE), we present here relevant records of twelve Carex (Cyperaceae) and four Hypericum (Hypericaceae) species. Regarding Carex, we present the novel report for South America of C.aztecica, as well as the first Ecuadorian records for C.brehmeri, C.collumanthus, C.fecunda, C.melanocystis and C.punicola. The three later records have additional biogeographical significance, as they represent the new northern limit of these species. We also include observations for another five species included in the Ecuadorian Red List of Endemic Plants. As a result, the list of native Carex reported for Ecuador would now include 52 taxa. With regard to Hypericum, we include the new report of H.sprucei for the province of Bolívar, and the confirmation of the presence of three rare species (H.acostanum, H.matangense, H.prietoi) in their type localities, although with extremely low population sizes. We discuss their conservation status and implications.

3.
Biomed Pharmacother ; 150: 113016, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35483192

RESUMO

Zephyranthes carinata Herb., a specie of the Amaryllidoideae subfamily, has been reported to have inhibitory activity against acetylcholinesterase. However, scientific evidence related to their bioactive alkaloids has been lacking. Thus, this study describes the isolation of the alkaloids of this plant, and their inhibition of the enzymes acetylcholinesterase (eeAChE) and butyrylcholinesterase (eqBuChE), being galanthine the main component. Additionally, haemanthamine, hamayne, lycoramine, lycorine, tazettine, trisphaeridine and vittatine/crinine were also isolated. The results showed that galanthine has significant activity at low micromolar concentrations for eeAChE (IC50 = 1.96 µg/mL). The in-silico study allowed to establish at a molecular level the high affinity and the way galanthine interacts with the active site of the TcAChE enzyme, information that corroborates the result of the experimental IC50. However, according to molecular dynamics (MD) analysis, it is also suggested that galanthine presents a different inhibition mode that the one observed for galanthamine, by presenting interaction with peripheral anionic binding site of the enzyme, which prevents the entrance and exit of molecules from the active site. Thus, in vitro screening assays plus rapid computer development play an essential role in the search for new cholinesterase inhibitors by identifying unknown bio-interactions between bioactive compounds and biological targets.


Assuntos
Alcaloides , Amaryllidaceae , Acetilcolinesterase/metabolismo , Alcaloides/farmacologia , Amaryllidaceae/química , Amaryllidaceae/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Simulação de Acoplamento Molecular
5.
Plants (Basel) ; 10(12)2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34961157

RESUMO

Natural products are one of the main sources for developing new drugs. The alkaloids obtained from the plant family Amaryllidaceae have interesting structures and biological activities, such as acetylcholinesterase inhibition potential, which is one of the mechanisms used for the palliative treatment of Alzheimer's disease symptoms. Herein we report the alkaloidal profile of bulbs and leaves extracts of Crinum × amabile collected in Ecuador and their in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. Using Gas Chromatography coupled to Mass Spectrometry (GC-MS), we identified 12 Amaryllidaceae alkaloids out of 19 compounds detected in this species. The extracts from bulbs and leaves showed great inhibitory activity against AChE and BuChE, highlighting the potential of Amaryllidaceae family in the search of bioactive molecules.

6.
Sci Rep ; 11(1): 17591, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475460

RESUMO

Particulate matter (PM) accounts for millions of premature deaths in the human population every year. Due to social and economic inequality, growing human dissatisfaction manifests in waves of strikes and protests all over the world, causing paralysis of institutions, services and circulation of transport. In this study, we aim to investigate air quality in Ecuador during the national protest of 2019, by studying the evolution of PM2.5 (PM ≤ 2.5 µm) concentrations in Ecuador and its capital city Quito using ground based and satellite data. Apart from analyzing the PM2.5 evolution over time to trace the pollution changes, we employ machine learning techniques to estimate these changes relative to the business-as-usual pollution scenario. In addition, we present a chemical analysis of plant samples from an urban park housing the strike. Positive impact on regional air quality was detected for Ecuador, and an overall - 10.75 ± 17.74% reduction of particulate pollution in the capital during the protest. However, barricade burning PM peaks may contribute to a release of harmful heavy metals (tire manufacture components such as Co, Cr, Zn, Al, Fe, Pb, Mg, Ba and Cu), which might be of short- and long-term health concerns.

8.
Am J Bot ; 108(6): 1042-1057, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34156704

RESUMO

PREMISE: A disjunct distribution, where a species' geographic range is discontinuous, can occur through vicariance or long-distance dispersal. Approximately 75 North American plant species exhibit a ~650 km disjunction between the Ozark and Appalachian regions. This disjunction is attributed to biogeographic forces including: (1) Eocene-Oligocene vicariance by the formation of the Mississippi embayment; (2) Pleistocene vicariance from interglacial flooding; (3) post-Pleistocene northward colonization from separate glacial refugia; (4) Hypsithermal vicariance due to climate fluctuations; and (5) recent long-distance dispersal. We investigated which of these pathways most likely gave rise to the Appalachian-Ozark disjunction in Delphinium exaltatum. METHODS: We genotyped populations of D. exaltatum from five Ozark and seven Appalachian localities, analyzed genetic structure, tested the order and timing of divergences using DIYABC, and conducted niche reconstructions up to 21,000 years before present (YBP). RESULTS: Populations fell into five main genetic clusters, i.e., a group in the central Appalachians, and four "lowland" groups. DIYABC analyses showed the central Appalachian and lowland lineages diverging 11,300 to17,000 YBP, and the lowland groups diverging 6800 to 10,900 YBP. Niche reconstructions showed that suitable climate for the central Appalachian lineage experienced large spatial discontinuity starting 14,000 YBP, such that divergence and persistence before this period is less plausible than divergence thereafter. CONCLUSIONS: Our results did not fully support any of the original hypotheses. Rather, the oldest divergence likely occurred after 13,500 YBP through expansion into newly opened habitat in the Appalachians. The Appalachian-Ozark disjunction likely resulted from northward dispersal of the lowland lineage as climate warmed during the Holocene.


Assuntos
Ecossistema , Variação Genética , Região dos Apalaches , Mississippi , América do Norte , Filogenia , Filogeografia
9.
S Afr J Bot ; 136: 91-99, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32982003

RESUMO

Alzheimer's disease is considered the most common cause of dementia and, in an increasingly aging population worldwide, the quest for treatment is a priority. Amaryllidaceae alkaloids are of main interest because of their cholinesterase inhibition potential, which is the main palliative treatment available for this disease. We evaluated the alkaloidal profile and the in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of bulb alkaloid extract of Phaedranassa dubia and Phaedranassa brevifolia collected in Ecuador. Using gas chromatography coupled to mass spectrometry (GC-MS), we identified typical Amaryllidaceae alkaloids in these species, highlighting the presence of lycorine-type alkaloids in P. dubia and haemanthamine/crinine-type in P. brevifolia. The species P. dubia and P. brevifolia showed inhibitory activities against AChE (IC50 values of 25.48 ± 0.39 and 3.45 ± 0.29 µg.mL-1, respectively) and BuChE (IC50 values of 114.96 ± 4.94 and 58.89 ± 0.55 µg.mL-1, respectively). Computational experiments allowed us to understand the interactions of the alkaloids identified in these samples toward the active sites of AChE and BuChE. In silico, some alkaloids detected in these Amaryllidaceae species presented higher estimated binding free energy toward BuChE than galanthamine. This is the first study about the alkaloid profile and biological potential of P. brevifolia species.

10.
Data Brief ; 31: 105845, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32637474

RESUMO

This data reports a list of all trees DBH > 10 cm in four 50 × 50 m (0.25 ha) permanent plots at Mashpi Rainforest Biodiversity Reserve in the Ecuadorian Chocó forest. Plots were established within an altitudinal gradient from 800 to 1200 m. We collected, labelled, measure and identify all trees found within the plots. All voucher specimens are available at the herbarium of Universidad Tecnológica Indoamérica (HUTI) in Quito, Ecuador. We found a total 133 stems representing 93 species and 36 families. Each plot had between 27 and 40 trees. Our list of species includes four threatened species under IUCN criteria. We also report the number of individuals of each species and its diameter at breast height (DBH) and height. This information is a baseline for further studies to contribute to the conservation of the Chocó, one of the 35 biodiversity hotspots is the Tumbes-Chocó-Magdalena. Even though this area is one of the most biodiverse in the planet, the botanical composition of the Chocó is still poorly known.

11.
Molecules ; 25(9)2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32365796

RESUMO

It is estimated that 50 million people in the world live with dementia, 60-70% of whom suffer from Alzheimer's disease (AD). Different factors are involved in the development of AD, including a reduction in the cholinergic neurotransmission level. The Amaryllidaceae plant family contains an exclusive, large, and still understudied alkaloid group characterized by a singular skeleton arrangement and a broad spectrum of biological activities. The chemistry and biodiversity of Ecuadorian representatives of the Phaedranassa genus (Amaryllidaceae) have not been widely studied. In this work, five Ecuadorian Phaedranassa species were examined in vitro for their activity towards the enzymes acetyl- (AChE) and butyrylcholinesterase (BuChE), and the alkaloid profile of bulb extracts was analyzed by GC-MS. The species Phaedranassa cuencana and Phaedranassa dubia showed the most AChE and BuChE inhibitory activity, respectively. To obtain insight into the potential role of the identified alkaloids in these inhibitory effects, docking experiments were carried out, and cantabricine showed in silico inhibitory activity against both cholinesterase structures. Our results show that Amaryllidaceae species from Ecuador are a potential source of new drugs for the palliative treatment of AD.


Assuntos
Amaryllidaceae/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Acetilcolinesterase/química , Alcaloides/química , Alcaloides/farmacologia , Sítios de Ligação , Descoberta de Drogas , Equador , Cromatografia Gasosa-Espectrometria de Massas , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Ligação Proteica , Relação Estrutura-Atividade
12.
Ecology ; 100(12): e02894, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31531983

RESUMO

We compiled a data set for all tree species collected to date in lowland Amazonian Ecuador in order to determine the number of tree species in the region. This data set has been extensively verified by taxonomists and is the most comprehensive attempt to evaluate the tree diversity in one of the richest species regions of the Amazon. We used four main sources of data: mounted specimens deposited in Ecuadorian herbaria only, specimen records of a large-scale 1-hectare-plot network (60 plots in total), data from the Missouri Botanical Garden Tropicos® database (MO), and literature sources. The list of 2,296 tree species names we provide in this data set is based on 47,486 herbarium records deposited in the following herbaria: Alfredo Paredes Herbarium (QAP), Catholic University Herbarium (QCA), Herbario Nacional del Ecuador (QCNE), Missouri Botanical Garden (MO), and records from an extensive sampling of 29,768 individuals with diameter at breast height (dbh) ≥10 cm recorded in our plot network. We also provide data for the relative abundance of species, geographic coordinates of specimens deposited in major herbaria around the world, whether the species is native or endemic, current hypothesis of geographic distribution, representative collections, and IUCN threat category for every species recorded to date in Amazonian Ecuador. These data are described in Metadata S1 and can be used for macroecological, evolutionary, or taxonomic studies. There are no copyright restrictions; data are freely available for noncommercial scientific use (CC BY 3.0). Please see Metadata S1 (Class III, Section B.1: Proprietary restrictions) for additional information on usage.

13.
Mol Biol Rep ; 46(3): 3519-3522, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30929161

RESUMO

Tropical anurans are among the most diverse and vulnerable organisms on Earth, yet the evolutionary mechanisms behind their diversity remain relatively unexplored. Epipedobates anthonyi is a poison frog that inhabits southern Ecuador and northern Peru along a broad elevational range (0-1800 m). Throughout its range, this species exhibits variation in phenotypic traits, such as color, advertisement calls, and alkaloid composition. The aim of this study is to isolate and characterize microsatellite loci to investigate patterns of genetic variation within the species. Using a next-generation sequencing approach to screen an enriched genomic library, we report twelve polymorphic microsatellite loci. The number of alleles per locus ranged from 7 to 15 per population. For the two populations tested, mean observed heterozygosity was 0.69 and 0.79, and mean expected heterozigosity was 0.84 and 0.85 respectively. Only locus EAN002 showed significant departure of HWE in both populations. None of the loci showed consistent null alleles in both populations. Also, no evidence of linkage disequilibrium was found across loci. In this paper, we report for the first time 12 microsatellite loci for E. anthonyi. These markers will be used to further elucidate evolutionary mechanisms underlying genetic and phenotypic variation across the species' range.


Assuntos
Anuros/genética , Alelos , Animais , Equador , Frequência do Gene/genética , Loci Gênicos , Genética Populacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Desequilíbrio de Ligação , Repetições de Microssatélites , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético/genética , Análise de Sequência de DNA
14.
Thomson, Scott A; Pyle, Richard L; Ahyong, Shane T; Alonso-Zarazaga, Miguel; Ammirati, Joe; Araya, Juan Francisco; Ascher, John S; Audisio, Tracy Lynn; Azevedo-Santos, Valter M; Bailly, Nicolas; Baker, William J; Balke, Michael; Barclay, Maxwell V. L; Barrett, Russell L; Benine, Ricardo C; Bickerstaff, James R. M; Bouchard, Patrice; Bour, Roger; Bourgoin, Thierry; Boyko, Christopher B; Breure, Abraham S. H; Brothers, Denis J; Byng, James W; Campbell, David; Ceriaco, Luis M. P; Cernak, Istvan; Cerretti, Pierfilippo; Chang, Chih-Han; Cho, Soowon; Copus, Joshua M; Costello, Mark J; Cseh, Andras; Csuzdi, Csaba; Culham, Alastair; D'Elia, Guillermo; d'Acoz, Cedric d'Udekem; Daneliya, Mikhail E; Dekker, Rene; Dickinson, Edward C; Dickinson, Timothy A; van Dijk, Peter Paul; Dijkstra, Klaas-Douwe B; Dima, Balint; Dmitriev, Dmitry A; Duistermaat, Leni; Dumbacher, John P; Eiserhardt, Wolf L; Ekrem, Torbjorn; Evenhuis, Neal L; Faille, Arnaud; Fernandez-Trianam, Jose L; Fiesler, Emile; Fishbein, Mark; Fordham, Barry G; Freitas, Andre V. L; Friol, Natalia R; Fritz, Uwe; Froslev, Tobias; Funk, Vicki A; Gaimari, Stephen D; Garbino, Guilherme S. T; Garraffoni, Andre R. S; Geml, Jozsef; Gill, Anthony C; Gray, Alan; Grazziotin, Felipe Gobbi; Greenslade, Penelope; Gutierrez, Eliecer E; Harvey, Mark S; Hazevoet, Cornelis J; He, Kai; He, Xiaolan; Helfer, Stephan; Helgen, Kristofer M; van Heteren, Anneke H; Garcia, Francisco Hita; Holstein, Norbert; Horvath, Margit K; Hovenkamp, Peter H; Hwang, Wei Song; Hyvonen, Jaakko; Islam, Melissa B; Iverson, John B; Ivie, Michael A; Jaafar, Zeehan; Jackson, Morgan D; Jayat, J. Pablo; Johnson, Norman F; Kaiser, Hinrich; Klitgard, Bente B; Knapp, Daniel G; Kojima, Jun-ichi; Koljalg, Urmas; Kontschan, Jeno; Krell, Frank-Thorsten; Krisai-Greilhuberm, Irmgard; Kullander, Sven; Latelle, Leonardo; Lattke, John E; Lencioni, Valeria; Lewis, Gwilym P; Lhano, Marcos G; Lujan, Nathan K; Luksenburg, Jolanda A; Mariaux, Jean; Marinho-Filho, Jader; Marshall, Christopher J; Mate, Jason F; McDonough, Molly M; Michel, Ellinor; Miranda, Vitor F. O; Mitroiulm, Mircea-Dan; Molinari, Jesus; Monks, Scott; Moore, Abigail J; Moratelli, Ricardo; Muranyi, David; Nakano, Takafumi; Nikolaeva, Svetlana; Noyes, John; Ohl, Michael; Oleas, Nora H; Orrell, Thomas; Pall-Gergele, Barna; Pape, Thomas; Papp, Viktor; Parenti, Lynne R; Patterson, David; Pavlinov, Igor Ya; Pine, Ronald H; Poczai, Peter; Prado, Jefferson; Prathapan, Divakaran; Rabeler, Richard K; Randall, John E; Rheindt, Frank E; Rhodin, Anders G. J; Rodriguez, Sara M; Rogers, D. Christopher; Roque, Fabio de O; Rowe, Kevin C; Ruedas, Luis A; Salazar-Bravo, Jorge; Salvador, Rodrigo B; Sangster, George; Sarmiento, Carlos E; Schigel, Dmitry S; Schmidt, Stefan; Schueler, Frederick W; Segers, Hendrik; Snow, Neil; Souza-Dias, Pedro G. B; Stals, Riaan; Stenroos, Soili; Stone, R. Douglas; Sturm, Charles F; Stys, Pavel; Teta, Pablo; Thomas, Daniel C; Timm, Robert M; Tindall, Brian J; Todd, Jonathan A; Triebel, Dagmar; Valdecasas, Antonio G; Vizzini, Alfredo; Vorontsova, Maria S; de Vos, Jurriaan M; Wagner, Philipp; Watling, Les; Weakley, Alan; Welter-Schultes, Francisco; Whitmore, Daniel; Wilding, Nicholas; Will, Kipling; Williams, Jason; Wilson, Karen; Winston, Judith E; Wuster, Wolfgang; Yanega, Douglas; Yeates, David K; Zaher, Hussam; Zhang, Guanyang; Zhang, Zhi-Qiang; Zhou, Hong-Zhang.
PLoS. Biol. ; 16(3): e2005075, 2018.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib15045
15.
Ecol Evol ; 7(22): 9639-9650, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29187996

RESUMO

Using complementary metrics to evaluate phylogenetic diversity can facilitate the delimitation of floristic units and conservation priority areas. In this study, we describe the spatial patterns of phylogenetic alpha and beta diversity, phylogenetic endemism, and evolutionary distinctiveness of the hyperdiverse Ecuador Amazon forests and define priority areas for conservation. We established a network of 62 one-hectare plots in terra firme forests of Ecuadorian Amazon. In these plots, we tagged, collected, and identified every single adult tree with dbh ≥10 cm. These data were combined with a regional community phylogenetic tree to calculate different phylogenetic diversity (PD) metrics in order to create spatial models. We used Loess regression to estimate the spatial variation of taxonomic and phylogenetic beta diversity as well as phylogenetic endemism and evolutionary distinctiveness. We found evidence for the definition of three floristic districts in the Ecuadorian Amazon, supported by both taxonomic and phylogenetic diversity data. Areas with high levels of phylogenetic endemism and evolutionary distinctiveness in Ecuadorian Amazon forests are unprotected. Furthermore, these areas are severely threatened by proposed plans of oil and mining extraction at large scales and should be prioritized in conservation planning for this region.

16.
PhytoKeys ; (48): 1-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25931969

RESUMO

New species of the genera Stenomesson and Eucharis (Amaryllidaceae) are described from Ecuador. Stenomessonecuadorense is the second species of the genus reported from that country, and the only endemic one. It is related to Stenomessonminiatum and Stenomessoncampanulatum, both from Peru, with which it shares orange flower color and the fusion of the staminal corona to the perianth tube. It differs from Stenomessonminiatum by the non-urceolate perianth, from Stenomessoncampanulatum by its shorter stamens and longer perianth, and from both by its lower montane, cloud forest habitat. Eucharisruthiana, found in the vicinity of Zamora, is related to Eucharismoorei from which it differs by the narrower leaves and tepals; short, deeply cleft staminal corona; the long teeth on either side of the free filaments; the narrowly subulate, incurved free filaments; and the shorter style. The green mature fruit and campanulate floral morphology place it in Eucharissubg.Heterocharis.


ResumenNuevas especies de los géneros Stenomesson y Eucharis (Amaryllidaceae) se describen para Ecuador. Stenomessonecuadorense es la segunda especie del género reportada de ese país y la única endémica. Está relacionada con Stenomessonminiatum y Stenomessoncampanulatum, ambos de Perú, con la que comparte el color naranja de la flor y la fusión de la copa estaminal al tubo del perianto. Se diferencia de Stenomessonminiatum por el perianto no urceolado, de Stenomessoncampanulatum por sus estambres más cortos y perianto más largo, yde ambos por su hábitat en bosque nuboso montano de baja altitud. Eucharisruthiana, que se encuentra en las cercanías de Zamora, está relacionada con Eucharismoorei, de cual difiere por las hojas y tépalos estrechos, copa estaminal corta y profundamente hendida, los dientes largos a ambos lados de los filamentos libres, filamentos libres encurvos y ligeramente subulados, y el estilo más corto. El fruto maduro verde y morfología floral campanulada lo posicionan en Eucharis subgénero Heterocharis.

17.
J Hered ; 103(4): 557-69, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22563126

RESUMO

The Tropical Andes is a diversity hotspot for plants, but there is a scant knowledge about patterns of genetic variation within its constituent species. Phaedranassa tunguraguae is an IUCN endangered plant species endemic to a single valley in the Ecuadorian Andes. We estimate the levels of genetic differentiation across the geographic distribution of P. tunguraguae using 12 microsatellite loci. We discuss factors that might influence the genetic structure of this species. Genetic distance was used to evaluate relationship among populations and geographic patterns. Bayesian methods were used to investigate population structure, migration, evidence of recent bottlenecks, and time of divergence. The 7 populations form 2 genetic clusters. These clusters show highly significant differentiation between them, along with isolation by distance. Allele richness decreases from the most diverse westernmost population to the least diverse easternmost population. The species overall shows an excess of homozygotes, with highest levels of inbreeding in the easternmost population. We found evidence of recent bottleneck events. Migration rates were in general low but were higher between populations within each of the clusters. Time of divergence between populations was related to historical volcanic activity in the area. Based on our results, we propose 2 management units for P. tunguraguae.


Assuntos
Espécies em Perigo de Extinção , Liliaceae/genética , Alelos , Teorema de Bayes , DNA de Plantas/química , Variação Genética , Geografia , Homozigoto , Repetições de Microssatélites , Dinâmica Populacional
18.
PLoS One ; 4(10): e7353, 2009 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-19806212

RESUMO

BACKGROUND: The Cocoseae is one of 13 tribes of Arecaceae subfam. Arecoideae, and contains a number of palms with significant economic importance, including the monotypic and pantropical Cocos nucifera L., the coconut, the origins of which have been one of the "abominable mysteries" of palm systematics for decades. Previous studies with predominantly plastid genes weakly supported American ancestry for the coconut but ambiguous sister relationships. In this paper, we use multiple single copy nuclear loci to address the phylogeny of the Cocoseae subtribe Attaleinae, and resolve the closest extant relative of the coconut. METHODOLOGY/PRINCIPAL FINDINGS: We present the results of combined analysis of DNA sequences of seven WRKY transcription factor loci across 72 samples of Arecaceae tribe Cocoseae subtribe Attaleinae, representing all genera classified within the subtribe, and three outgroup taxa with maximum parsimony, maximum likelihood, and Bayesian approaches, producing highly congruent and well-resolved trees that robustly identify the genus Syagrus as sister to Cocos and resolve novel and well-supported relationships among the other genera of the Attaleinae. We also address incongruence among the gene trees with gene tree reconciliation analysis, and assign estimated ages to the nodes of our tree. CONCLUSIONS/SIGNIFICANCE: This study represents the as yet most extensive phylogenetic analyses of Cocoseae subtribe Attaleinae. We present a well-resolved and supported phylogeny of the subtribe that robustly indicates a sister relationship between Cocos and Syagrus. This is not only of biogeographic interest, but will also open fruitful avenues of inquiry regarding evolution of functional genes useful for crop improvement. Establishment of two major clades of American Attaleinae occurred in the Oligocene (ca. 37 MYBP) in Eastern Brazil. The divergence of Cocos from Syagrus is estimated at 35 MYBP. The biogeographic and morphological congruence that we see for clades resolved in the Attaleinae suggests that WRKY loci are informative markers for investigating the phylogenetic relationships of the palm family.


Assuntos
Arecaceae/genética , Cocos/genética , Teorema de Bayes , Evolução Biológica , DNA/metabolismo , Genes de Plantas , Geografia , Funções Verossimilhança , Repetições de Microssatélites , Modelos Genéticos , Modelos Estatísticos , Filogenia , Folhas de Planta/metabolismo , Análise de Sequência de DNA , Fatores de Transcrição/metabolismo
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