Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 18(9): e0291122, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37682874

RESUMO

Welwitschia mirabilis Hook.f. (Welwitschiaceae, Gnetales) is a gymnosperm plant unique in its habit with an isolated taxonomic position. This species is dioecious, but no studies of its photosynthetic activity were conducted with examination of differences among male and female plants. To fill this gap, the day and night photosynthetic activity of male and female specimens of Welwitschia mirabilis cultivated in the botanical garden was studied in controlled conditions. Photosynthetic activity was studied using net photosynthetic rate (PN), stomatal conductance (gs) and intercellular CO2 concentration (Ci) parameters. Additionally, a normalized difference vegetation index (NDVI) was used to assess the condition among male and female plants in full sunlight. The studied Welwitschia plants revealed variability in photosynthetic activity both during the day and the night. The photosynthetic activity was low in the morning hours and higher in the afternoon. There is a difference in the photosynthetic activity during the night between sexes, being higher in female specimens. Stomatal density was evaluated separately for adaxial and abaxial leaf surfaces. Statistically significant differences in the stomatal density on abaxial and adaxial leaf surfaces were observed in both sexes, especially distinctive in female specimens. NDVI has revealed that there were weak differences between male and female plants.


Assuntos
Mirabilis , Sementes , Cycadopsida , Jardinagem , Hábitos
2.
Pestic Biochem Physiol ; 163: 216-226, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31973860

RESUMO

Due to the increasing use of chlorinated organic compounds, environmental pollution is a key issue in agricultural and industrial areas. In this study, biodegradation of chloroacetanilide herbicides, such as alachlor and metolachlor, by eight fungal strains of Trichoderma spp. originating from different microorganism collections was investigated. The tested fungi converted 80-99% of alachlor and 40-79% of metolachlor after 7 days of incubation. Biotransformation of herbicides was performed mainly by dechlorination and hydroxylation reactions. Eight alachlor metabolites and four byproducts of metolachlor conversion were detected in Trichoderma cultures, including two metolachlor intermediates for the first time identified in fungi. Moreover, in the cultures of six Trichoderma strains supplemented with chloroacetanilides, a decrease in toxicity was observed toward tested Artemia franciscana crustaceans. Simultaneously, 7 days after the application of the spores of T. koningii IM 0956, T. citrinoviride IM 6325, T. harzianum KKP 534, T. viride KKP 792 and T. virens DSM 1963 the length of roots and shoots of rapeseed seedlings treated with alachlor or metolachlor significantly increased. All tested strains exhibited plant growth-promoting traits, such as siderophore production, 1-aminocyclopropane-1-carboxylate deaminase (ACCD) activity, and phosphate solubilization, even in the presence of chloroacetanilide herbicides.


Assuntos
Herbicidas , Trichoderma , Acetamidas , Biodegradação Ambiental , Biotransformação
3.
Ecotoxicol Environ Saf ; 184: 109629, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31509783

RESUMO

To investigate the induction of oxidative stress and antioxidant response in the chloroacetanilides-degrading Trichoderma spp. under alachlor and metolachlor exposure, a comparative analysis using popular biomarkers was employed. An increased intracellular level of reactive oxygen species (ROS; especially superoxide anion [O2-]) as well as products of lipid and protein oxidation after 24 h incubation with the herbicides confirmed chloroacetanilide-induced oxidative stress in tested Trichoderma strains. However, the considerable decline in the ROS levels and the carbonyl group content (biomarkers of protein peroxidation) in a time-dependent manner and changes in the antioxidant enzyme activities indicated an active response against chloroacetanilide-induced oxidative stress and the mechanism of tolerance in tested fungi. Moreover, the tested herbicides clearly modified the phospholipids (PLs) content in Trichoderma spp. in the stationary phase of growth, which was manifested through the difference in phosphatidic acid (PA), phosphatidylethanolamine (PE) and phosphatidylcholines (PC) levels. Despite enhanced lipid peroxidation and changes in PLs in most tested fungi, only a slight modification in membrane integrity of Trichoderma spp. under chloroacetanilides exposure was noted. The obtained results suggest that the alterations in the antioxidant system and the PLs profile of Trichoderma spp. might be useful biomarkers of chloroacetanilide-induced oxidative stress.


Assuntos
Herbicidas/metabolismo , Estresse Oxidativo , Fosfolipídeos/metabolismo , Trichoderma/metabolismo , Acetamidas/metabolismo , Acetamidas/toxicidade , Antioxidantes/metabolismo , Biodegradação Ambiental , Herbicidas/toxicidade , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Trichoderma/efeitos dos fármacos
4.
Ecol Evol ; 9(12): 6833-6848, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31380019

RESUMO

Forest undergrowth plants are tightly connected with the shady and humid conditions that occur under the canopy of tropical forests. However, projected climatic changes, such as decreasing precipitation and increasing temperature, negatively affect understory environments by promoting light-demanding and drought-tolerant species. Therefore, we aimed to quantify the influence of climate change on the spatial distribution of three selected forest undergrowth plants, Dracaena Vand. ex L. species, D. afromontana Mildbr., D. camerooniana Baker, and D. surculosa Lindl., simultaneously creating the most comprehensive location database for these species to date. A total of 1,223 herbarium records originating from tropical Africa and derived from 93 herbarium collections worldwide have been gathered, validated, and entered into a database. Species-specific Maxent species distribution models (SDMs) based on 11 bioclimatic variables from the WorldClim database were developed for the species. HadGEM2-ES projections of bioclimatic variables in two contrasting representative concentration pathways (RCPs), RCP2.6 and RCP8.5, were used to quantify the changes in future potential species distribution. D. afromontana is mostly sensitive to temperature in the wettest month, and its potential geographical range is predicted to decrease (up to -63.7% at RCP8.5). Optimum conditions for D. camerooniana are low diurnal temperature range (6-8°C) and precipitation in the wettest season exceeding 750 mm. The extent of this species will also decrease, but not as drastically as that of D. afromontana. D. surculosa prefers high precipitation in the coldest months. Its potential habitat area is predicted to increase in the future and to expand toward the east. This study developed SDMs and estimated current and future (year 2050) potential distributions of the forest undergrowth Dracaena species. D. afromontana, naturally associated with mountainous plant communities, was the most sensitive to predicted climate warming. In contrast, D. surculosa was predicted to extend its geographical range, regardless of the climate change scenario.

5.
J Plant Physiol ; 229: 158-163, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30096586

RESUMO

2,4-dichlorophenoxyacetic acid (2,4-D) is among the most commonly used herbicides applied for weed control during wheat cultivation. However, its application could affect wheat growth. The present study investigates the effect of the ascomycetous fungus Trichoderma harzianum on lipid peroxidation, phospholipids, signaling lipids and phospholipase D in the seedlings of wheat (Triticum aestivum L.) treated with 2,4-D (2.5 mg L-1). In the group of 4-day-old seedlings exposed to the herbicide, increased lipid peroxidation and inhibition of growth were observed in shoots and roots. Moreover, elevated levels of oxylipins were noted. Among them, the amount of 13-HOTrE oxygenated from linolenic acid (18:3) increased the most significantly. Concurrently, in the seedlings inoculated with T. harzianum, growth was stimulated when the level of phosphatidylcholine (PC) increased. Moreover, in wheat seedlings treated with 2,4-D and T. harzianum, the level of lipid peroxidation was similar to that in the control and there was no increase observed in oxylipins and phospholipase D activity. T. harzianum might have partly alleviated the toxic effect of 2,4-D on wheat seedlings.


Assuntos
Ácido 2,4-Diclorofenoxiacético/farmacologia , Trichoderma/patogenicidade , Triticum/metabolismo , Triticum/microbiologia , Estresse Oxidativo/fisiologia , Fosfatidilcolinas/metabolismo , Fosfolipase D/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Brotos de Planta/microbiologia , Plântula/efeitos dos fármacos , Plântula/metabolismo , Plântula/microbiologia , Triticum/efeitos dos fármacos
6.
Ecotoxicol Environ Saf ; 162: 1-9, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29957402

RESUMO

The filamentous fungus Trichoderma koningii is capable of fast and effective eliminate alachlor (90% after 72 h when added separately and 80-60% in the presence of 1-5 mM of copper). After 168 h over 99% elimination of alachlor resulted in detoxification and was connected with the mitigation of reactive oxygen species (ROS) production. Using MS/MS techniques, seven dechlorinated and hydroxylated metabolites were identified. Cytochrome P450 and laccase participate in biotransformation of the herbicide by this non-ligninolytic fungus. Laccase activity is stimulated both by copper and the mixture of copper and alachlor, which seems to be important for combined pollutants. T. koningii is characterized by high tolerance to copper (up to 7.5 mM). The metal content in mycelia reached 0.9-7.76 mg in 1 g of dry biomass. Our results suggest that T. koningii strain seems to be a promising tool for bioremediation of agricultural areas co-contaminated with copper-based fungicides and chloroacetanilide herbicides.


Assuntos
Acetamidas/metabolismo , Cobre/metabolismo , Herbicidas/metabolismo , Trichoderma/metabolismo , Acetamidas/toxicidade , Biodegradação Ambiental , Biotransformação , Cobre/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Herbicidas/toxicidade , Íons , Lacase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Trichoderma/efeitos dos fármacos , Trichoderma/enzimologia
7.
PLoS One ; 13(6): e0199677, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29933393

RESUMO

The study reports the response to herbicide of the 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading fungal strain Umbelopsis isabellina. A comparative analysis covered 41 free amino acids as well as 140 lipid species of fatty acids, phospholipids, acylglycerols, sphingolipids, and sterols. 2,4-D presence led to a decrease in fungal catalase activity, associated with a higher amount of thiobarbituric acid-reactive substances (TBARS). Damage to cells treated with the herbicide resulted in increased membrane permeability and decreased membrane fluidity. Detailed lipidomic profiling showed changes in the fatty acids composition such as an increase in the level of linoleic acid (C18:2). Moreover, an increase in the phosphatidylethanolamine/phosphatidylcholine ratio was observed. Analysis of fungal lipid profiles revealed that the presence of 2,4-D was accompanied by the accumulation of triacylglycerols, a decrease in ergosterol content, and a considerable rise in the level of sphingolipid ceramides. In the exponential phase of growth, increased levels of leucine, glycine, serine, asparagine, and hydroxyproline were found. The results obtained in our study confirmed that in the cultures of U. isabellina oxidative stress was caused by 2,4-D. The herbicide itself forced changes not only to membrane lipids but also to neutral lipids and amino acids, as the difference of tested compounds profiles between 2,4-D-containing and control samples was consequently lower as the pesticide degradation progressed. The presented findings may have a significant impact on the basic understanding of 2,4-D biodegradation and may be applied for process optimization on metabolomic and lipidomic levels.


Assuntos
Ácido 2,4-Diclorofenoxiacético , Membrana Celular/metabolismo , Fungos não Classificados/metabolismo , Herbicidas , Lipídeos de Membrana/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ácido 2,4-Diclorofenoxiacético/metabolismo , Ácido 2,4-Diclorofenoxiacético/farmacologia , Herbicidas/metabolismo , Herbicidas/farmacologia
8.
Lipids ; 53(4): 447-456, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29741213

RESUMO

Hydra, as sit-and-wait predators with limited food selectivity, could serve as model organisms for the analysis of the effect of a particular dietary component on growth and reproduction. We investigated the effect of food quality and of diets enriched with palmitic (PAM) or α-linolenic acid (ALA) on the life history traits of two hydra species: Hydra oligactis and Hydra vulgaris. We tested the hypothesis that a diet enriched with polyunsaturated fatty acids (PUFA) can stimulate growth and reproduction in simple metazoans with a sit-and-wait type of predatory strategy. Our results revealed that a diet based on Artemia nauplii, which are not a natural food for freshwater hydra, stimulated growth, asexual reproduction, and survival in hydra. Artemia nauplii were characterized by the highest lipid content of all used food sources. The analysis of the fatty acid content of hydra indicated the domination the n-6 fatty acids over n-3 (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and ALA). Arachidonic acid appeared to be the dominant PUFA in Hydra, irrespective of diet supplementation with palmitic acid or ALA. The dietary supplementation of ALA negatively affected the survival, asexual reproductive rate, and size of clonal offspring of H. oligactis and had no effect on the life history traits of H. vulgaris. Our results also suggest that the hydras are not able to efficiently convert ALA into other essential fatty acids, such as EPA and DHA. To our knowledge, this is the first report about the adverse effects of n-3 fatty acid supplementation in primitive metazoans such as hydra.


Assuntos
Hydra/efeitos dos fármacos , Hydra/fisiologia , Ácido Palmítico/farmacologia , Reprodução Assexuada/efeitos dos fármacos , Ácido alfa-Linolênico/farmacologia , Animais , Hydra/crescimento & desenvolvimento , Análise de Sobrevida
9.
Lasers Med Sci ; 33(7): 1521-1526, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29725945

RESUMO

Endothelium plays a key role in maintaining vascular homeostasis by secreting active factors involved in many biological processes such as hemostasis, angiogenesis, and inflammation. Hyperglycemia in diabetic patients causes dysfunction of endothelial cells. Soluble fractions of adhesion molecules like sE-selectin and vascular cell adhesion molecule (sVCAM) are considered as markers of endothelial damage. The low-level laser therapy (LLLT) effectively supports the conventional treatment of vascular complications in diabetes, for example hard-to-heal wounds in patients with diabetic foot syndrome. The aim of our study was to evaluate the effect of low-energy laser at the wavelength of 635 nm (visible light) and 830 nm (infrared) on the concentration of adhesion molecules: sE-selectin and sVCAM in the supernatant of endothelial cell culture of HUVEC line. Cells were cultured under high-glucose conditions of 30 mM/L. We have found an increase in sE-selectin and sVCAM levels in the supernatant of cells cultured under hyperglycemic conditions. This fact confirms detrimental influence of hyperglycemia on vascular endothelial cell cultures. LLLT can modulate the inflammation process. It leads to a decrease in sE-selectin and sVCAM concentration in the supernatant and an increase in the number of endothelial cells cultured under hyperglycemic conditions. The influence of LLLT is greater at the wavelength of 830 nm.


Assuntos
Moléculas de Adesão Celular/metabolismo , Hiperglicemia/metabolismo , Hiperglicemia/radioterapia , Terapia com Luz de Baixa Intensidade , Contagem de Células , Selectina E/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos da radiação , Humanos , Hiperglicemia/patologia , Solubilidade , Molécula 1 de Adesão de Célula Vascular/metabolismo
10.
Environ Sci Pollut Res Int ; 25(3): 2738-2743, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29139072

RESUMO

The chemical 2,4-dichlorophenoxyacetic acid (2,4-D) is used in agriculture as a herbicide. Its intensive use has an adverse effect on the environment. This study involved examining the degradation of 2,4-D compound by the filamentous fungus Umbelopsis isabellina. After 5 days of incubation, 98% of the herbicide (added at 25 mg L-1) was found to be removed. The elimination of 2,4-D by U. isabellina was connected with the formation of 2,4-dichlorophenol (2,4-DCP), which resulted in a 60% decrease in the sample toxicity toward Artemia franciscana larvae. The metabolism of 2,4-D was inhibited by the addition of metyrapone, a known cytochrome P450 inhibitor. It provides evidence that cytochrome P450 system is involved in 2,4-D metabolism in U. isabellina.


Assuntos
Ácido 2,4-Diclorofenoxiacético/análise , Sistema Enzimático do Citocromo P-450/metabolismo , Fungos/metabolismo , Herbicidas/análise , Poluentes do Solo/análise , Ácido 2,4-Diclorofenoxiacético/metabolismo , Biodegradação Ambiental , Fungos/enzimologia , Herbicidas/metabolismo , Inativação Metabólica , Modelos Teóricos , Oxirredução , Poluentes do Solo/metabolismo
11.
Sensors (Basel) ; 16(7)2016 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-27355949

RESUMO

This paper presents the results of verification of certain non-contact measurement methods of plant scanning to estimate morphological parameters such as length, width, area, volume of leaves and/or stems on the basis of computer models. The best results in reproducing the shape of scanned objects up to 50 cm in height were obtained with the structured-light DAVID Laserscanner. The optimal triangle mesh resolution for scanned surfaces was determined with the measurement error taken into account. The research suggests that measuring morphological parameters from computer models can supplement or even replace phenotyping with classic methods. Calculating precise values of area and volume makes determination of the S/V (surface/volume) ratio for cacti and other succulents possible, whereas for classic methods the result is an approximation only. In addition, the possibility of scanning and measuring plant species which differ in morphology was investigated.


Assuntos
Simulação por Computador , Dessecação , Plantas/anatomia & histologia , Aloe/anatomia & histologia , Processamento de Imagem Assistida por Computador , Lasers , Fenótipo , Folhas de Planta/anatomia & histologia , Reprodutibilidade dos Testes
12.
Lasers Med Sci ; 31(5): 825-31, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26861982

RESUMO

Diabetes mellitus is considered to be a very serious lifestyle disease leading to cardiovascular complications and impaired wound healing observed in the diabetic foot syndrome. Chronic hyperglycemia is the source of the endothelial activation. The inflammatory process in diabetes is associated with the secretion of inflammatory cytokines by endothelial cells, e.g., tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6). The method of phototherapy using laser beam of low power (LLLT-low-level laser therapy) effectively supports the conventional treatment of diabetic vascular complications such as diabetic foot syndrome. The aim of our study was to evaluate the effect of low-power laser irradiation at two wavelengths (635 and 830 nm) on the secretion of inflammatory factors (TNF-α and IL-6) by the endothelial cell culture-HUVEC line (human umbilical vein endothelial cell)-under conditions of hyperglycemia. It is considered that adverse effects of hyperglycemia on vascular endothelial cells may be corrected by the action of LLLT, especially with the wavelength of 830 nm. It leads to the reduction of TNF-α concentration in the supernatant and enhancement of cell proliferation. Endothelial cells play an important role in the pathogenesis of diabetes; however, a small number of studies evaluate an impact of LLLT on these cells under conditions of hyperglycemia. Further work on this subject is warranted.


Assuntos
Células Endoteliais/efeitos da radiação , Hiperglicemia/radioterapia , Interleucina-6/efeitos da radiação , Terapia com Luz de Baixa Intensidade/métodos , Fator de Necrose Tumoral alfa/efeitos da radiação , Linhagem Celular , Proliferação de Células/efeitos da radiação , Citocinas/efeitos da radiação , Humanos , Veias Umbilicais
13.
Laterality ; 21(1): 76-84, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26305485

RESUMO

Lateralization developed very early in evolution and it is a characteristic of a wide range of representatives from the animal kingdom. The aim of the present study was to examine the spontaneous laterality in mice (Mus musculus) with the T-maze test. We wanted to check if this kind of functional asymmetry occurs at a population level, and also if there are gender differences in this regard. The study involved 40 mice Crl:CD1. The research procedure was simple: mice had to choose one arm of the T-shaped apparatus to find the exit. The animals performed the 10 trails one after another. We took into account only the animals' fist reactions while preparing results. Most of the animals (68%) chose the right arm of the maze. The lateralization was stronger among females--75% of them had preferences for the right side. The majority of animals, which preferred the right side, were from the food deprivation group. However, the results did not unequivocally resolve whether mice evince the functional asymmetry at the population level, or whether there are gender differences in this area. Further research with a larger group and multiple observations for each animal are required to answer these questions.


Assuntos
Comportamento Exploratório/fisiologia , Lateralidade Funcional/fisiologia , Caracteres Sexuais , Animais , Feminino , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos ICR , Orientação/fisiologia
14.
Lasers Med Sci ; 30(1): 273-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25231826

RESUMO

Growth factors as vascular endothelial growth factor (VEGF), produced by the endothelial cells, take an essential part in pathological and physiological angiogenesis. The possibility of angiogenesis modulation by application of laser radiation may contribute to the improvement of its use in this process. Thus, the aim of the study was to investigate the influence of low-level laser therapy (LLLT) on the proliferation of endothelial cells, secretion of VEGF-A and presence of soluble VEGF receptors (sVEGFR-1 and sVEGFR-2) in the medium after in vitro culture. Isolated human umbilical vein endothelial cells (HUVECs) were irradiated using a diode laser at a wavelength of 635 nm and power density of 1,875 mW/cm(2). Depending on radiation energy density, the experiment was conducted in four groups: I 0 J/cm(2) (control group), II 2 J/cm(2), III 4 J/cm(2), and IV 8 J/cm(2). The use of laser radiation wavelength of 635 nm, was associated with a statistically significant increase in proliferation of endothelial cells (p = 0.0041). Moreover, at 635-nm wavelength, all doses of radiation significantly reduced the concentration of sVEGFR-1 (p = 0.0197).


Assuntos
Células Endoteliais/efeitos da radiação , Terapia com Luz de Baixa Intensidade/métodos , Neovascularização Fisiológica , Técnicas de Cultura de Células , Proliferação de Células , Endotélio Vascular , Células Endoteliais da Veia Umbilical Humana , Humanos , Lasers Semicondutores , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
15.
PhytoKeys ; (26): 101-12, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24194672

RESUMO

A morphologically distinct element of the group of Dracaena species from Thailand and Burma with undifferentiated leaf sheaths, no leaf blade central costa, free tepals and free thickened filaments known as Chan nuu or Chan pha krai in Thai is shown to be a distinct species, Dracaena kaweesakii Wilkin & Suksathan based on habit, leaf base and margin, inflorescence axis indumentum and floral characters. It is described and illustrated. Ecological and conservation status assessment information are provided.

16.
Mol Phylogenet Evol ; 60(1): 122-36, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21459153

RESUMO

Phylogenetic relationships of the monocot family Hypoxidaceae (Asparagales), which occurs mainly in the Southern Hemisphere, were reconstructed using four plastid DNA regions (rbcL, trnL intron, trnL-F intergenic spacer, and trnS-G intergenic spacer) for 56 ingroup taxa including all currently accepted genera and seven species of the closely related families Asteliaceae, Blandfordiaceae, and Lanariaceae. Data were analyzed by applying parsimony, maximum likelihood and Bayesian methods. The intergenic spacer trnS-G--only rarely used in monocot research--contributed a substantial number of potentially parsimony informative characters. Hypoxidaceae consist of three well-supported major clades, but their interrelationships remain unresolved. Our data indicate that in the Pauridia clade one long-distance dispersal event occurred from southern Africa to Australia. Long-distance dispersal scenarios may also be likely for the current distribution of Hypoxis, which occurs on four continents. In the Curculigo clade, the present distribution of Curculigo s.s. on four continents could support a Gondwanan origin, but the level of divergence is too low for this hypothesis to be likely. The main clades correspond well with some floral characters, habit and palynological data, whereas chromosomal data exhibit plasticity and probably result from polyploidization and subsequent dysploidy and/or aneuploidy. Evolutionary flexibility is also suggested by the number of reported pollination syndromes: melittophily, myophily, sapromyophily, and cantharophily. Based on our phylogenetic results, we suggest cautious nomenclatural reorganization to generate monophyly at the generic level.


Assuntos
Magnoliopsida/classificação , Magnoliopsida/genética , Filogenia , Plastídeos/genética , Teorema de Bayes , DNA Espaçador Ribossômico/genética , Evolução Molecular , Íntrons/genética , Magnoliopsida/anatomia & histologia , Dados de Sequência Molecular , Filogeografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA