Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Int J Mol Sci ; 25(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38396766

RESUMO

The manuscript provides an overview of recent scientific reports on the properties and range of health-promoting effects of acerola (Malpighia emarginata DC) fruits and leaves. Acerola is a natural raw material that, in its unprocessed form, is known to be a rich source of vitamin C and polyphenolic compounds. For this reason, the consumption of acerola may provide a number of health-promoting benefits, particularly related to its strong anti-free radical effects. The review discusses anti-inflammatory and anticancer effects of acerola fruit and leaves as well as its therapeutic effects on selected physiological processes in the human system. Their biochemical mechanisms are also explained. Recommendations for the consumption of acerola in the prevention of inflammatory and free radical diseases are presented. The part of the article devoted to anticancer effects of acerola describes the possibilities of using the edible parts of this raw material to obtain products and preparations of potential use in cancer prevention and therapy.


Assuntos
Antioxidantes , Malpighiaceae , Humanos , Antioxidantes/farmacologia , Antioxidantes/análise , Ácido Ascórbico/análise , Rutina , Frutas/química , Radicais Livres/análise , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/análise , Malpighiaceae/química , Malpighiaceae/fisiologia
2.
Protoplasma ; 260(4): 1047-1062, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36512090

RESUMO

The flowers of the species of Malpighiaceae in the Neotropical Region are relatively uniform in their morphology due to their dependence on oil-collecting bees as their main pollinators. However, many species of the genus Galphimia seem to have acquired a different floral syndrome, lacking markedly zygomorphic flowers and developed elaiophores in the calyx. Likewise, these species present anthers with great development, probably in response to the selection of pollinators that collect pollen. Galphimia australis incorporated some of these traits but also retained some residual characteristics typical of species pollinated by oil bees. This leads to many questions on how these flowers ensure their pollination. Inquiring about the reduction or modification of these characteristics allows us to understand how G. australis achieves a different pollination syndrome. In this research, we carry out a detailed morphological and anatomical study of the flowers and pollen grain devolvement of G. australis and floral visitors were observed and captured. Results were analyzed in order to determine how this species changed from the oil-floral syndrome, typical of neotropical Malpighiaceae, to one syndrome with pollen as the main reward.


Assuntos
Galphimia , Malpighiaceae , Animais , Abelhas , Polinização/fisiologia , Malpighiaceae/fisiologia , Flores/anatomia & histologia , Pólen/fisiologia
3.
Mol Phylogenet Evol ; 143: 106692, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31770589

RESUMO

Worldwide distributed tropical savannas were established only in the Miocene, with climatic cooling and rise of C4 grasses. However, there is evidence for an earlier presence of savanna-like vegetation in southern parts of South America. Here we investigated the biogeographic history of a clade of solitary bees which have endemic groups in areas covered by savannas and other types of open vegetation as well as forested areas. We hypothesized that these bees originated in savanna-like biomes and that shifts to forested areas and floral host shifts increased species diversification along their evolutionary history. We reconstructed a comprehensive phylogeny for Tapinotaspidini bees based majorly on original DNA sequences. We then used macroevolutionary tools to estimate ancestral range area and reconstructed ancestral habitat (open versus forested) and host plant association to analyze the effects of shifts in vegetation type and flower hosts on their diversification. Tapinotaspidini bees originated in the Paleocene and in a savanna-type, Cerrado-like, which is reinforced by reconstruction of open vegetation as the most probable ancestral area, thus bringing additional evidence to a much earlier origin of this vegetation type in South America. Shifts to forested areas occurred at least three times in a period of 30 Ma and were responsible for slight increases in diversification rates. Malpighiaceae is the ancestral floral host; host broadening occurred only in the Miocene and at least in three occasions. Host shifts, i.e. from Malpighiaceae to other oil families, occurred in the Eocene and Miocene. Both host broadening and host shifts did not significantly alter diversification rates, however exploitation of other oil sources were important in occupying new habitats. The link between biomes and host plant shifts and changes in diversification rate brings us additional insights into the evolution of bees and associated flora in South America.


Assuntos
Abelhas/classificação , Animais , Abelhas/genética , Abelhas/fisiologia , Evolução Biológica , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fósseis/história , Pradaria , História Antiga , Malpighiaceae/crescimento & desenvolvimento , Malpighiaceae/fisiologia , Filogenia , Filogeografia , América do Sul
4.
Hig. aliment ; 33(288/289): 1472-1476, abr.-maio 2019. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1482185

RESUMO

O objetivo do presente trabalho foi avaliar a influência da concentração da maltodextrina e da temperatura de entrada de secagem sob as características físico-químicas de polpa de acerola em pó. As acerolas maduras foram selecionadas, lavadas, sanitizadas, enxaguadas e despolpada. As polpas foram divididas em quatro tratamentos, utilizando-se duas concentrações de maltodextrina (14 e 26%) que foram atomizadas em spray dryer em duas temperaturas (128 e 152°C). A polpa em pó e in natura foram analisadas quanto a umidade, SST, ATT, pH e carotenoides. De acordo com os resultados obtidos foi possível verificar que os teores de umidade foram influenciados pela temperatura e concentração de maltodextrina. A acidez da polpa em pó diminui com o aumento da do agente carreador. O teor de carotenoides não apresentou diferença significativa entre os tratamentos estudados. Para o processo de atomização da acerola por spray dryer indica-se o uso de maltodextrina a 26% independente da temperatura.


Assuntos
Dextrinas/efeitos adversos , Fenômenos Químicos , Malpighiaceae/fisiologia , Malpighiaceae/química , Temperatura Alta/efeitos adversos , Conservação de Alimentos
5.
Protoplasma ; 256(4): 1133-1144, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30953173

RESUMO

We analyzed the gynoecium morphology and anatomy of Tricomaria usillo in young and mature flowers from diverse populations in order to analyze the differentiation of structure and function of the parts of the carpel. We also aimed to find the potential pollinators and associate the morphology of the gynoecium with its role. We compare the characteristics of the gynoecium of T. usillo and discuss the carpel dimorphism with other genera within the Carolus clade in relation with their pollination syndromes. Carpels were processed according to classic techniques for scanning electron microscopy and bright field microscopy. We conducted field observation in different populations of T. usillo and captured the insects that were identified to specific level. The gynoecium of T. usillo shows inter-population and intra-individual variability. Some have three well-developed carpels, while most of them present two posterior carpels with differentiated styles and stigmas and the anterior one with a shorter style with or without stigma. The ovary has three locules with one ovule each. A compitum is formed and all ovules may be fecundated. However, fruits have generally one seed that develops in the anterior locule. Centris brethesi is the potential pollinator. The gynoecium of T. usillo reflects part of the variation in the carpel dimorphism that probably arose in the branch of the Carolus clade, and evolved in diverse ways in the lineages of this group. Tricomaria usillo seems to represent a recent transition towards reaching a stable form of carpel dimorphism and definitive division of labors of the carpels.


Assuntos
Flores/anatomia & histologia , Malpighiaceae/anatomia & histologia , Flores/fisiologia , Malpighiaceae/fisiologia , Microscopia Eletrônica de Varredura , Óvulo Vegetal/anatomia & histologia , Óvulo Vegetal/fisiologia , Polinização
6.
Plant Biol (Stuttg) ; 21(1): 167-175, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30184303

RESUMO

Long-lived flowers increase pollen transfer rates, but these entail high water and carbon maintenance costs. The retention of pollinated and reward-free old flowers enhances pollinator visitation to young receptive flowers by increasing floral display size. This mechanism is associated with acropetal inflorescences or changes in flower colour and openness, but the retention of unchanging solitary flowers remains overlooked. We examined pollination-dependent variation in floral longevity and determined stigmatic receptivity, pollen viability and pollen removal rates among flower ages in Kielmeyera regalis, a Neotropical savanna shrub. We also evaluated the effects of floral display size on pollinator visitation rates. Lastly, we determined whether old flowers are unvisited and exclusively increase pollinator attraction to young flowers through flower removal experiments. Regardless of pollination treatment, flowers lasted fully open with no detectable physical changes for 3 days. Over time, stigmas remained receptive but >95% of pollen was removed. Pollinator visitation significantly increased with floral display size and intermediate percentages (15-30%) of newly opened flowers. Accordingly, the retention of reward-free and unvisited old flowers increased young flower-pollinator interaction. Our results reveal the importance of a prolonged floral longevity in increasing pollinator attraction toward newly opened receptive flowers without changes in flower colour and form. We conclude that the retention of pollinated, reward-free and unvisited colour-unchanged old flowers in K. regalis is a strategy that counteracts the water use costs associated with the maintenance of large flowers with increased mate opportunities in a pollen-limited scenario.


Assuntos
Flores/fisiologia , Malpighiaceae/fisiologia , Pigmentação/fisiologia , Polinização/fisiologia , Animais , Abelhas/fisiologia , Pólen/fisiologia
7.
Protoplasma ; 255(5): 1433-1442, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29594351

RESUMO

The family Malpighiaceae, particularly in the Neotropic, shows a similar floral morphology. Although floral attraction and rewards to pollinators are alike, stigmas and styles show more diversity. The stigmas were described covered with a thin and impermeable cuticle that needs to be ruptured by the mechanical action of the pollinators. However, this characteristic was only mentioned for a few species and the anatomy and ultrastructure of the stigmas were not explored. In this work, we analyze the morphology, anatomy, and ultrastructure of the stigma and style of Callaeum psilophyllum. Moreover, we identify the potential pollinators in order to evaluate how the disposition of the stigmas is related with their size and its role in the exposure of the receptive stigmatic surface. Our observations indicate that Centris flavifrons, C. fuscata, C. tarsata, and C. trigonoides are probably efficient pollinators of C. psilophyllum. The three stigmas are covered by a cuticle that remained intact in bagged flowers. The flowers exposed to visitors show the cuticle broken, more secretion in the intercellular spaces between sub-stigmatic cells and abundant electron-dense components inside vacuoles in stigmatic papillae. This indicates that the stigmas prepares in similar ways to receive pollen grains, but the pollinator action is required to break the cuticle, and once pollen tubes start growing, stigmatic and sub-stigmatic cells release more secretion by a granulocrine process.


Assuntos
Malpighiaceae/fisiologia , Flores/metabolismo , Flores/fisiologia , Flores/ultraestrutura , Malpighiaceae/metabolismo , Malpighiaceae/ultraestrutura , Polinização/fisiologia
8.
Oecologia ; 180(4): 1103-12, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26686200

RESUMO

Several mistletoe species are able to grow and reproduce on both deciduous and evergreen hosts, suggesting a degree of plasticity in their ability to cope with differences in intrinsic host functions. The aim of this study was to investigate the influence of host phenology on mistletoe water relations and leaf gas exchange. Mistletoe Passovia ovata parasitizing evergreen (Miconia albicans) hosts and P. ovata parasitizing deciduous (Byrsonima verbascifolia) hosts were sampled in a Neotropical savanna. Photosynthetic parameters, diurnal cycles of stomatal conductance, pre-dawn and midday leaf water potential, and stomatal anatomical traits were measured during the peak of the dry and wet seasons, respectively. P. ovata showed distinct water-use strategies that were dependent on host phenology. For P. ovata parasitizing the deciduous host, water use efficiency (WUE; ratio of photosynthetic rate to transpirational water loss) was 2-fold lower in the dry season than in the wet season; in contrast, WUE was maintained at the same level during the wet and dry seasons in P. ovata parasitizing the evergreen host. Generally, mistletoe and host diurnal cycles of stomatal conductance were linked, although there were clear differences in leaf water potential, with mistletoe showing anisohydric behaviour and the host showing isohydric behaviour. Compared to mistletoes attached to evergreen hosts, those parasitizing deciduous hosts had a 1.4-fold lower stomatal density and 1.2-fold wider stomata on both leaf surfaces, suggesting that the latter suffered less intense drought stress. This is the first study to show morphophysiological differences in the same mistletoe species parasitizing hosts of different phenological groups. Our results provide evidence that phenotypical plasticity (anatomical and physiological) might be essential to favour the use of a greater range of hosts.


Assuntos
Adaptação Fisiológica , Secas , Erva-de-Passarinho/fisiologia , Folhas de Planta/fisiologia , Estações do Ano , Árvores/fisiologia , Água , Pradaria , Malpighiaceae/fisiologia , Melastomataceae/fisiologia , Erva-de-Passarinho/anatomia & histologia , Fenótipo , Fotossíntese/fisiologia , Folhas de Planta/anatomia & histologia , Estômatos de Plantas/anatomia & histologia , Estômatos de Plantas/fisiologia , Transpiração Vegetal/fisiologia , Clima Tropical
9.
Am J Bot ; 101(12): 2088-96, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25480706

RESUMO

UNLABELLED: • PREMISE OF THE STUDY: Few studies have analyzed the physiological performance of different life stages and the expression of ontogenetic niche shifts in lianas. Here, we analyzed the photosynthetic and morphological acclimation of seedlings of Stigmaphyllon lindenianum, Combretum fruticosum, and Bonamia trichantha to distinctive light conditions in a tropical dry forest and compared their response with the acclimation response of adult canopy lianas of the same species. We expected acclimation to occur faster through changes in leaf photochemistry relative to adaptation in morphology, consistent with the life history strategies of these lianas.• METHODS: Seedlings were assigned to the following light treatments: high light (HH), low light (LL), sun to shade (HL), and shade to sun (LH) in a common garden. After 40 d, HL and LH seedlings were exposed to opposite light treatments. Light response curves, the maximum photosynthetic rate in the field (Amax), and biomass allocation were monitored for another 40 d on leaves expanded before transfer.• KEY RESULTS: Photosynthetic responses, Amax, and biomass of Stigmaphyllon and Combretum varied with light availability. Physiological characters were affected by current light environment. The previous light environment (carryover effects) only influenced Amax. Morphological characters showed significant carryover effects. Stigmaphyllon showed high morphological and physiological plasticity. Sun-exposed seedlings of this liana increased stem biomass and switched from self-supporting to climbing forms.• CONCLUSIONS: Acclimation in seedlings of these lianas is consistent with the response of adult lianas in the canopy in direction, but not in magnitude. There was no evidence for ontogenetic niche shifts in the acclimation response.


Assuntos
Aclimatação , Combretum/fisiologia , Convolvulaceae/fisiologia , Escuridão , Malpighiaceae/fisiologia , Fotossíntese , Caules de Planta/crescimento & desenvolvimento , Biomassa , Combretum/anatomia & histologia , Combretum/crescimento & desenvolvimento , Convolvulaceae/anatomia & histologia , Convolvulaceae/crescimento & desenvolvimento , Ecossistema , Malpighiaceae/anatomia & histologia , Malpighiaceae/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Plântula/anatomia & histologia , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Estresse Fisiológico , Luz Solar , Clima Tropical
10.
Proc Natl Acad Sci U S A ; 111(16): 5914-9, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24706921

RESUMO

Many major branches in the Tree of Life are marked by stereotyped body plans that have been maintained over long periods of time. One possible explanation for this stasis is that there are genetic or developmental constraints that restrict the origin of novel body plans. An alternative is that basic body plans are potentially quite labile, but are actively maintained by natural selection. We present evidence that the conserved floral morphology of a species-rich flowering plant clade, Malpighiaceae, has been actively maintained for tens of millions of years via stabilizing selection imposed by their specialist New World oil-bee pollinators. Nine clades that have lost their primary oil-bee pollinators show major evolutionary shifts in specific floral traits associated with oil-bee pollination, demonstrating that developmental constraint is not the primary cause of morphological stasis in Malpighiaceae. Interestingly, Malpighiaceae show a burst in species diversification coinciding with the origin of this plant-pollinator mutualism. One hypothesis to account for radiation despite morphological stasis is that although selection on pollinator efficiency explains the origin of this unique and conserved floral morphology, tight pollinator specificity subsequently permitted greatly enhanced diversification in this system.


Assuntos
Abelhas/fisiologia , Flores/anatomia & histologia , Flores/fisiologia , Malpighiaceae/anatomia & histologia , Malpighiaceae/fisiologia , Polinização/fisiologia , Simbiose/fisiologia , Animais , Evolução Biológica , Dados de Sequência Molecular , Filogenia , Especificidade da Espécie
11.
An Acad Bras Cienc ; 86(1): 347-57, 2014 03.
Artigo em Inglês | MEDLINE | ID: mdl-24676172

RESUMO

Oil-collecting bees are the natural pollinators of oil-flower plants, but little is known about the pollination process and the effectiveness of their pollination service to the reproductive success of their host plants. In species of Byrsonima the reproductive system have been described as auto-compatible or self-incompatible. We studied the reproductive system of Byrsonima cydoniifolia, the fructification by means of short, medium and long-distance cross pollinations, the morphology and floral biology and the pollination interactions with species of oil-collecting bees. By means of controlled pollinations we found self-incompatibility caused by abortion of most self-pollinated flowers and demonstrated that the prevailing cross pollination ensuring the reproductive success of B. cydoniifolia is the long-distance cross pollination and Centridini bees; Epicharis nigrita, particularly, are the pollinators promoting the gene flow between genetically distinct populations.


Assuntos
Abelhas/fisiologia , Malpighiaceae/fisiologia , Polinização/fisiologia , Animais , Abelhas/classificação , Feminino , Masculino , Malpighiaceae/classificação , Reprodução
12.
C R Biol ; 337(1): 62-70, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24439552

RESUMO

Malpighiaceae ovules have a well-developed nucellus; previous observations indicate that during seed development, the endosperm does not proliferate, thus, remaining scarce. This study aimed at identifying the nutritive tissues during seed development in Malpighiaceae, focusing especially on the endosperm. We analysed the seed development of Janusia mediterranea, J. occhionii, Mascagnia cordifolia, and Tetrapterys chamaecerasifolia, which were collected and processed by traditional methods for light microscopy. Ovules are subcampylotropous, crassinucellate and unitegmic in Janusia and bitegmic in M. cordifolia and T. chamaecerasifolia. The nucellus is well developed and protrudes through the micropyle, touching the funicular obturator. During development, a pachychalaza is formed, and the integuments coalesce in bitegmic species. Through a series of nucellar cell divisions, the perisperm is formed. In Janusia species, the endosperm is not produced. In M. cordifolia and T. chamaecerasifolia, the endosperm is nuclear, but it is scarce and ephemeral. The mature seed is exalbuminous, and the perisperm is consumed, and thus, the mature embryo is total. The absence of endosperm in Janusia is newly observed for the family and indicates functional transfer for the abundant perisperm.


Assuntos
Malpighiaceae/fisiologia , Sementes/crescimento & desenvolvimento , Brasil , Endosperma , Flores/química , Frutas/química , Histocitoquímica , Malpighiaceae/genética , Valor Nutritivo , Óvulo Vegetal/química , Sementes/química
13.
Ann Bot ; 107(8): 1323-34, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21610210

RESUMO

BACKGROUND AND AIMS: Most Neotropical species of Malpighiaceae produce floral fatty oils in calyx glands to attract pollinating oil-collecting bees, which depend on this resource for reproduction. This specialized type of pollination system tends to be lost in members of the family that occur outside the geographic distribution (e.g. Africa) of Neotropical oil-collecting bees. This study focused on the pollination ecology, chemical ecology and reproductive biology of an oil flower species, Pterandra pyroidea (Malpighiaceae) from the Brazilian Cerrado. Populations of this species consist of plants with oil-secreting (glandular) flowers, plants with non-oil-secreting flowers (eglandular) or a mix of both plant types. This study specifically aims to clarify the role of eglandular morphs in this species. METHODS: Data on pollinators were recorded by in situ observations. Breeding system experiments were conducted by isolating inflorescences and by enzymatic reactions. Floral resources, pollen and floral oils offered by this species were analysed by staining and a combination of various spectroscopic methods. KEY RESULTS: Eglandular flowers of P. pyroidea do not act as mimics of their oil-producing conspecifics to attract pollinators. Instead, both oil-producing and oil-free flowers depend on pollen-collecting bees for reproduction, and their main pollinators are bumble-bees. Floral oils produced by glandular flowers are less complex than those described in closely related genera. CONCLUSIONS: Eglandular flowers represent a shift in the pollination system in which oil is being lost and pollen is becoming the main reward of P. pyroidea flowers. Pollination shifts of this kind have hitherto not been demonstrated empirically within Neotropical Malpighiaceae and this species exhibits an unusual transition from a specialized towards a generalized pollination system in an area considered the hotspot of oil-collecting bee diversity in the Neotropics. Transitions of this type provide an opportunity to study ongoing evolutionary mechanisms that promote the persistence of species previously involved in specialized mutualistic relationships.


Assuntos
Abelhas/fisiologia , Flores/fisiologia , Malpighiaceae/fisiologia , Óleos de Plantas/metabolismo , Polinização/fisiologia , Animais , Comportamento Animal , Evolução Biológica , Brasil , Cruzamento , Ecologia , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Feminino , Funções Verossimilhança , Modelos Logísticos , Masculino , Malpighiaceae/química , Malpighiaceae/genética , Fenótipo , Óleos de Plantas/análise , Pólen/fisiologia , Reprodução/fisiologia
14.
Plant Foods Hum Nutr ; 66(2): 129-35, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21503669

RESUMO

Genotoxic and antigenotoxic effects of acerola fruit at two stages of ripeness were investigated using mice blood cells. The results show that no ripeness stage of acerola extracts presented any genotoxic potential to damage DNA (Comet assay) or cytotoxicity (MTT assay). When antigenotoxic activity was analyzed, unripe fruit presented higher DNA protection than ripe fruit (red color) extract. The antioxidant capacity of substances also showed that unripe samples inhibit the free radical DPPH more significantly than the ripe ones. The results about determination of compounds made using HPLC showed that unripe acerola presents higher levels of vitamin C as compared to ripe acerola. Thus, vitamin C and the complex mixture of nutrients of Malpighia glabra L., and especially its ripeness stages, influenced the interaction of the fruit extract with the DNA. Acerola is usually consumed when ripe (red fruit), although it is the green fruit (unripe) that has higher potential as beneficial to DNA, protecting it against oxidative stress.


Assuntos
Antioxidantes/farmacologia , Dano ao DNA/efeitos dos fármacos , Malpighiaceae/química , Malpighiaceae/fisiologia , Extratos Vegetais/farmacologia , Animais , Antimutagênicos/farmacologia , Ácido Ascórbico/análise , Compostos de Bifenilo/metabolismo , Cromatografia Líquida de Alta Pressão , Ensaio Cometa , Testes Imunológicos de Citotoxicidade , Radicais Livres/metabolismo , Frutas/química , Frutas/fisiologia , Leucócitos/efeitos dos fármacos , Leucócitos/fisiologia , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Picratos/metabolismo
15.
J Anim Ecol ; 78(5): 1096-101, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19515098

RESUMO

1. In the Neotropics, most plants depend on animals for pollination. Solitary bees are the most important vectors, and among them members of the tribe Centridini depend on oil from flowers (mainly Malpighiaceae) to feed their larvae. This specialized relationship within 'the smallest of all worlds' (a whole pollination network) could result in a 'tiny world' different from the whole system. This 'tiny world' would have higher nestedness, shorter path lengths, lower modularity and higher resilience if compared with the whole pollination network. 2. In the present study, we contrasted a network of oil-flowers and their visitors from a Brazilian steppe ('caatinga') to whole pollination networks from all over the world. 3. A network approach was used to measure network structure and, finally, to test fragility. The oil-flower network studied was more nested (NODF = 0.84, N = 0.96) than all of the whole pollination networks studied. Average path lengths in the two-mode network were shorter (one node, both for bee and plant one-mode network projections) and modularity was lower (M = 0.22 and four modules) than in all of the whole pollination networks. Extinctions had no or small effects on the network structure, with an average change in nestedness smaller than 2% in most of the cases studied; and only two species caused coextinctions. The higher the degree of the removed species, the stronger the effect and the higher the probability of a decrease in nestedness. 4. We conclude that the oil-flower subweb is more cohesive and resilient than whole pollination networks. Therefore, the Malpighiaceae have a robust pollination service in the Neotropics. Our findings reinforce the hypothesis that each ecological service is in fact a mosaic of different subservices with a hierarchical structure ('webs within webs').


Assuntos
Abelhas/fisiologia , Malpighiaceae/fisiologia , Modelos Biológicos , Polinização/fisiologia , Animais , Biodiversidade
16.
Curr Biol ; 19(6): 514-7, 2009 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-19285402

RESUMO

The optimal deployment of reproductive resources by hermaphrodites to male versus female function (i.e., their sex allocation) depends directly on opportunities for mating. If hermaphrodites occur among females, selection should favor those with a male-biased allocation because increased male allocation enhances siring success when eggs are abundant. Similarly, when hermaphrodites co-occur with males, selection should favor those that bias their allocation toward their female function. We tested these predictions by allowing hermaphrodites of the plant Mercurialis annua to evolve in either the presence or absence of males. In the presence of males, hermaphrodites did not evolve, probably because they were already strongly female biased in the base population. However, hermaphrodites mating in the absence of males evolved greater male allocation, as predicted. Our results provide the first demonstration of an evolutionary response to the frequency of unisexuals in hermaphroditic sex allocation, and they verify the quantitative phase predicted by models for the transition between hermaphroditism and dioecy.


Assuntos
Transtornos do Desenvolvimento Sexual/psicologia , Identidade de Gênero , Comportamento Sexual Animal , Comportamento Sexual , Animais , Evolução Biológica , Cruzamentos Genéticos , Feminino , Flores/fisiologia , Humanos , Masculino , Malpighiaceae/genética , Malpighiaceae/fisiologia , Reprodução
17.
J Econ Entomol ; 102(1): 265-73, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19253645

RESUMO

Acerola (Malpighia emarginata DC; Malpighiaceae) is an important fruit crop in Brazil. Among its pollinators, Centris (Heterocentris) analis (F.) stands out due to its abundance at flowers and prompt acceptance of trap-nests. For the first time, we propose the commercial use of Centris bees as orchard pollinators. To develop protocols for rearing and management of these bees, we analyzed trap-nest acceptance, brood-cell construction, and larval diet in Acerola orchards. Although Centris species, in general, use numerous pollen host plants, females of C. analis showed remarkable flower fidelity to Acerola for pollen supply when nesting in the orchard. Such fidelity was previously expected only for floral oil collection. The ease of acceptance of trap-nests by females of C. analis, their prolonged yearly activity period, multivoltine life history, and high pollinator efficiency characterize C. analis as an excellent potentially manageable pollinator in Acerola orchards.


Assuntos
Abelhas/fisiologia , Malpighiaceae/fisiologia , Comportamento de Nidação , Polinização , Agricultura , Animais , Brasil , Dieta , Feminino , Larva/fisiologia , Fatores de Tempo
18.
Plant Biol (Stuttg) ; 10(5): 660-73, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18761504

RESUMO

Extrafloral nectaries are nectar-secreting structures that are especially common among the woody flora of the Brazilian cerrado, a savanna-like vegetation. In this study, we provide morphological and anatomical descriptions of extrafloral nectaries (EFNs) occurring on vegetative and reproductive organs of several plant species from the cerrado, and discuss their function and ecological relevance. We describe the morphology and anatomy of EFNs of 40 species belonging to 15 woody families using scanning electron microscopy and light microscopy. We categorise EFNs following a structural-topographical classification, and characterise the vascularised and complex nectaries, amorphous nectaries and secretory trichomes. Fabaceae, Bignoniaceae, Malpighiaceae and Vochysiaceae were the plant families with the majority of species having EFNs. Ten species possess more than one morphotype of gland structure. Observations and experimental field studies in the cerrado support the anti-herbivore role of EFN-gathering ants in this habitat. Additional morphological studies of EFNs-bearing plants, including other growth forms (e.g. herbs and lianas), are being undertaken and will hopefully cast further light on the ecological relevance of these glands in the cerrado, especially with respect to their attractiveness to multiple visitors.


Assuntos
Metabolismo dos Carboidratos , Magnoliopsida/ultraestrutura , Bignoniaceae/fisiologia , Bignoniaceae/ultraestrutura , Brasil , Ecossistema , Fabaceae/fisiologia , Fabaceae/ultraestrutura , Magnoliopsida/fisiologia , Malpighiaceae/fisiologia , Malpighiaceae/ultraestrutura
19.
Arch Latinoam Nutr ; 56(2): 101-9, 2006 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-17024954

RESUMO

The acerola (Malpighia emarginata Sessé y Mociño ex DC) is a wild plant grown in zones of tropical and subtropical climate. Acerola is origin from South of Mexico, Central America and Septentrional area of South America. Its scientific name was adopted in 1986 by the International Council of Vegetable Genetic Resources. Malpighia emarginata has a subglobulose drupa fruit with three seeds which account between the 19 - 25% of the total weight. The diameter and weight of the fruit varies between 1 - 4 cm and 2 - 15 g, respectively. The fruit shows green color when it is developing, which changes to yellow and red tones when it is mature. Each plant produces annually 20 - 30 kg of fruits. This fruit contents macro and micronutrients: proteins (0.21-0.80 g/100 g), fats (0.23-0.80 g/100 g), carbohydrates (3.6-7.80 g/100 g), mineral salts (iron 0.24, calcium 11.7, phosphorus 17.1 mg/100 g) and vitamins (thiamine 0.02, riboflavine 0.07, piridoxine 8.7 mg/100 g). Its high content in vitamin C (695 a 4827 mg/100 g) is remarkable, therefore acerola has an increasing economic value by its great consume during last years. Acerola also presents carotenoids and bioflavonoids which provide important nutritive value and its potential use as antioxidant. Brazil has a climate and soil appropriate for the culture of acerola, thus this country is the main mundial productor. Acerola is commercialised as juices, jams, ices, gelatins, sweets or liquors. Bibliographical data have been mainly supplied by Electronic Resources of the University of Seville and the University do Vale do Itajaí (Santa Catarina, Brazil).


Assuntos
Ácido Ascórbico/análise , Frutas/química , Malpighiaceae/química , Proteínas de Plantas/análise , Antioxidantes/análise , Carotenoides/análise , Análise de Alimentos , Frutas/classificação , Frutas/fisiologia , Humanos , Malpighiaceae/classificação , Malpighiaceae/fisiologia , Valor Nutritivo
20.
New Phytol ; 166(2): 663-72, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15819928

RESUMO

This study is aimed to understand the role of life-history traits in determining the genetic structure of populations. We used Erythroxylum havanense, a distylous shrub with synchronous and massive patterns of flowering and fruiting. We suggest that the high concentration of ephemeral resources produced by mass flowering satiates both pollinators and frugivores, restricting gene flow and leading to genetic differentiation among populations. Using random amplified polymorphic DNAs as genetic markers, we estimated genetic diversity and structure statistics to quantify the amount and distribution of genetic variation within and among five populations from the Pacific coast of Mexico. High levels of genetic variation within populations and significant differentiation among populations located very near to each other were found. Furthermore, spatial autocorrelation analysis indicated the presence of significant genetic structure at short spatial distances. We suggest that by influencing the foraging behavior of pollinators and frugivores, mass flowering may produce the observed patterns of genetic structure, while small differences in flowering or fruiting phenology could further reinforce the isolation of nearby populations.


Assuntos
Flores/fisiologia , Variação Genética , Malpighiaceae/genética , Animais , Comportamento Alimentar , Frutas/fisiologia , Malpighiaceae/fisiologia , México , Filogenia , Fatores de Tempo , Clima Tropical
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...