Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time.

Science.gov (United States)

van Dijk, Aalt D J; Molenaar, Jaap

2017-01-01

The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time

Directory of Open Access Journals (Sweden)

Aalt D.J. van Dijk

2017-04-01

Full Text Available The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

Estudios morfo-anatómicos en nectarios florales y extraflorales de Triumfetta rhomboidea (Malvaceae, Grewioideae Morpho-anatomical studies of the floral and extrafloral nectaries of Triumfetta rhomboidea (Malvaceae, Grewioideae

Directory of Open Access Journals (Sweden)

Elsa Lattar

2009-07-01

Full Text Available La morfo-anatomía de los nectarios florales y extraflorales tricomáticos de Triumfetta rhomboidea Jacq. se estudió con microscopio óptico y microscopio electrónico de barrido. Las cinco glándulas nectaríferas florales, están localizadas en el androginóforo, mientras que los nectarios extraflorales se hallan en los márgenes de la base de la lámina en la hoja y en los márgenes de la bráctea. Las diferencias observadas entre ellos están dadas por el tamaño y la forma de las células epidérmicas basales, el número de las células del pie y de la cabezuela de los tricomas glandulares, los idioblastos del parénquima secretor y el tejido vascular que inerva los nectarios. El análisis de la varianza mostró diferencias significativas entre los nectarios florales y extraflorales en las siguientes variables: longitud y diámetro de la cabezuela, longitud y ancho del pie, pared periclinal de la célula epidérmica basal. Estos resultados fueron congruentes con el análisis de componentes principales (ACP. La longitud de cabezuela y la pared periclinal de la célula basal permitieron reconocer los tres tipos de nectarios, mientras el diámetro de cabezuela y la longitud y ancho de pie sólo diferenciaron los nectarios florales de los extraflorales. Los resultados de este trabajo se discuten en relación a información previa sobre el género.The morpho-anatomy of the floral and extrafloral trichomatic nectaries of Triumfetta rhomboidea Jacq. was studied by light and scanning electron microscope. Five nectariferous glands are located on the androgynophore, whereas extrafloral nectaries are on the margins at the base of the leaf and on the margins of the bract. The differences observed between them are the size and shape of the epidermal basal cells, the number of the foot and the head cells of the glandular trichomes, the idioblasts of the secretor parenchyma and the vascular tissue which innervates the nectaries. The analysis of variance

Nectar sugar production across floral phases in the Gynodioecious Protandrous Plant Geranium sylvaticum [corrected].

Science.gov (United States)

Varga, Sandra; Nuortila, Carolin; Kytöviita, Minna-Maarit

2013-01-01

Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separation of pollen dispersal and stigma receptivity) has rarely been examined. In this study, sugar production in nectar standing crop and secretion rate were investigated in Geranium sylvaticum, a gynodioecious plant species with protandry (i.e. with hermaphrodite flowers releasing their pollen before the stigma is receptive). We found that flowers from hermaphrodites produced more nectar than female flowers in terms of total nectar sugar content. In addition, differences in nectar production among floral phases were found in hermaphrodite flowers but not in female flowers. In hermaphrodite flowers, maximum sugar content coincided with pollen presentation and declined slightly towards the female phase, indicating nectar reabsorption, whereas in female flowers sugar content did not differ between the floral phases. These differences in floral reward are discussed in relation to visitation patterns by pollinators and seed production in this species.

Floral flavonoids and ultraviolet patterns in Viguiera (Compositae)

International Nuclear Information System (INIS)

Rieseberg, L.H.; Schilling, E.E.

1985-01-01

Variation occurs among species of Viguiera series Viguiera for ultraviolet (UV) absorption/reflection patterns of ligules. Floral flavonoids that cause UV absorption occur in epidermal papillae. Flavonoids are further localized to the proximal portion of the ligule in the seven taxa that have only proximal UV absorption. Floral flavonoids involved in UV absorption consist of flavone, flavonol, and anthochlor (chalcone/aurone) glycosides. Quercetin 3-methyl ether glycosides characterize the ligules of 10 taxa occurring in Baja California, Mexico, and nearby areas, and these taxa appear to form one taxonomic group. The anthochlor pair, marein/maritimein, characterizes V. dentata, and the lack of ligule flavonoids distinguishes V. potosina from the remaining taxa. The presence of the anthochlor pair, marein/maritimein, only in V. dentata and the lack of ligule flavonoids in V. potosina concur with other data to indicate that these species are not correctly placed with each other or with the other species currently included in series Viguiera. (author)

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum).

Science.gov (United States)

Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

2016-12-01

Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions.

Citogenética e biologia molecular em leucemia linfocítica crônica

OpenAIRE

Chauffaille,Maria de Lourdes L. F.

2005-01-01

O estudo das alterações cromossômicas em LLC é importante no auxílio ao diagnóstico, quando da identificação de doença clonal e no diagnóstico diferencial com outras linfoproliferações; no acompanhamento evolutivo ao permitir a detecção de alterações adicionais; na escolha terapêutica, como, por exemplo, na presença de del(17p) que confere resistência à terapia; no monitoramento do tratamento, ao permitir a avaliação de doença residual ou no diagnóstico da transformação (Síndrome de Richter)....

Pollination systems and floral traits in cerrado woody species of the Upper Taquari region (central Brazil

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F. Q. Martins

Full Text Available Plant species present flowers with varied morphological and functional features, which may be associated to pollination systems, including species pollinated by wind, beetles, moths, bees, small insects, birds, or bats. We calculated the frequencies of the pollination systems among woody species in five cerrado fragments in central-western Brazil and tested whether the pollination systems were indeed related to floral traits. We sampled 2,280 individuals, belonging to 121 species, ninety-nine of which were described in relation to all floral traits. Most species had diurnal anthesis, pale colors, and open flowers. The most frequent groups were those composed by the species pollinated by bees, small insects, and moths. A Principal Component Analysis of the species and floral traits showed that there was a grouping among species with some pollination systems, such as those pollinated mainly by beetles, moths, birds, and bats, for which inferences based on the floral traits are recommended in cerrado sites. For the species pollinated mainly by bees or small insects, inferences based on the floral traits are not recommended, due to the large dispersion of the species scores and overlapping between these two groups, which probably occurred due to the specificity absence in plant-pollinator relationships.

The Role of Abiotic Environmental Conditions and Herbivory in Shaping Bacterial Community Composition in Floral Nectar

Science.gov (United States)

Samuni-Blank, Michal; Izhaki, Ido; Laviad, Sivan; Bar-Massada, Avi; Gerchman, Yoram; Halpern, Malka

2014-01-01

Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that “everything is everywhere, but the environment selects”. Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria) and animals as dispersal vectors, the environmental and geographic factors that shape microbial communities in floral nectar are unknown. We studied culturable bacterial communities in Asphodelus aestivus floral nectar and in its typical herbivorous bug Capsodes infuscatus, along an aridity gradient. Bacteria were sampled from floral nectar and bugs at four sites, spanning a geographical range of 200 km from Mediterranean to semi-arid conditions, under open and bagged flower treatments. In agreement with the niche assembly hypothesis, the differences in bacterial community compositions were explained by differences in abiotic environmental conditions. These results suggest that microbial model systems are useful for addressing macro-ecological questions. In addition, similar bacterial communities were found in the nectar and on the surface of the bugs that were documented visiting the flowers. These similarities imply that floral nectar bacteria dispersal is shaped not only by air borne bacteria and nectar consumers as previously reported, but also by visiting vectors like the mirid bugs. PMID:24922317

Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae).

Science.gov (United States)

Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

2016-04-13

Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness.

Separating selection by diurnal and nocturnal pollinators on floral display and spur length in Gymnadenia conopsea.

Science.gov (United States)

Sletvold, Nina; Trunschke, Judith; Wimmergren, Carolina; Agren, Jon

2012-08-01

Most plants attract multiple flower visitors that may vary widely in their effectiveness as pollinators. Floral evolution is expected to reflect interactions with the most important pollinators, but few studies have quantified the contribution of different pollinators to current selection on floral traits. To compare selection mediated by diurnal and nocturnal pollinators on floral display and spur length in the rewarding orchid Gymnadenia conopsea, we manipulated the environment by conducting supplemental hand-pollinations and selective pollinator exclusions in two populations in central Norway. In both populations, the exclusion of diurnal pollinators significantly reduced seed production compared to open pollination, whereas the exclusion of nocturnal pollinators did not. There was significant selection on traits expected to influence pollinator attraction and pollination efficiency in both the diurnal and nocturnal pollination treatment. The relative strength of selection among plants exposed to diurnal and nocturnal visitors varied among traits and populations, but the direction of selection was consistent. The results suggest that diurnal pollinators are more important than nocturnal pollinators for seed production in the study populations, but that both categories contribute to selection on floral morphology. The study illustrates how experimental manipulations can link specific categories of pollinators to observed selection on floral traits, and thus improve our understanding of how species interactions shape patterns of selection.

Separable roles of UFO during floral development revealed by conditional restoration of gene function.

Science.gov (United States)

Laufs, Patrick; Coen, Enrico; Kronenberger, Jocelyne; Traas, Jan; Doonan, John

2003-02-01

The UNUSUAL FLORAL ORGANS (UFO) gene is required for several aspects of floral development in Arabidopsis including specification of organ identity in the second and third whorls and the proper pattern of primordium initiation in the inner three whorls. UFO is expressed in a dynamic pattern during the early phases of flower development. Here we dissect the role of UFO by ubiquitously expressing it in ufo loss-of-function flowers at different developmental stages and for various durations using an ethanol-inducible expression system. The previously known functions of UFO could be separated and related to its expression at specific stages of development. We show that a 24- to 48-hour period of UFO expression from floral stage 2, before any floral organs are visible, is sufficient to restore normal petal and stamen development. The earliest requirement for UFO is during stage 2, when the endogenous UFO gene is transiently expressed in the centre of the wild-type flower and is required to specify the initiation patterns of petal, stamen and carpel primordia. Petal and stamen identity is determined during stages 2 or 3, when UFO is normally expressed in the presumptive second and third whorl. Although endogenous UFO expression is absent from the stamen whorl from stage 4 onwards, stamen identity can be restored by UFO activation up to stage 6. We also observed floral phenotypes not observed in loss-of-function or constitutive gain-of-function backgrounds, revealing additional roles of UFO in outgrowth of petal primordia.

Caffeine in floral nectar enhances a pollinator's memory of reward.

Science.gov (United States)

Wright, G A; Baker, D D; Palmer, M J; Stabler, D; Mustard, J A; Power, E F; Borland, A M; Stevenson, P C

2013-03-08

Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees' bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.

Soil fungal effects on floral signals, rewards, and aboveground interactions in an alpine pollination web.

Science.gov (United States)

Becklin, Katie M; Gamez, Guadalupe; Uelk, Bryan; Raguso, Robert A; Galen, Candace

2011-08-01

Plants interact with above- and belowground organisms; the combined effects of these interactions determine plant fitness and trait evolution. To better understand the ecological and evolutionary implications of multispecies interactions, we explored linkages between soil fungi, pollinators, and floral larcenists in Polemonium viscosum (Polemoniaceae). Using a fungicide, we experimentally reduced fungal colonization of krummholz and tundra P. viscosum in 2008-2009. We monitored floral signals and rewards, interactions with pollinators and larcenists, and seed set for fungicide-treated and control plants. Fungicide effects varied among traits, between interactions, and with environmental context. Treatment effects were negligible in 2008, but stronger in 2009, especially in the less-fertile krummholz habitat. There, fungicide increased nectar sugar content and damage by larcenist ants, but did not affect pollination. Surprisingly, fungicide also enhanced seed set, suggesting that direct resource costs of soil fungi exceed indirect benefits from reduced larceny. In the tundra, fungicide effects were negligible in both years. However, pooled across treatments, colonization by mycorrhizal fungi in 2009 correlated negatively with the intensity and diversity of floral volatile organic compounds, suggesting integrated above- and belowground signaling pathways. Fungicide effects on floral rewards in P. viscosum link soil fungi to ecological costs of pollinator attraction. Trait-specific linkages to soil fungi should decouple expression of sensitive and buffered floral phenotypes in P. viscosum. Overall, this study demonstrates how multitrophic linkages may lead to shifting selection pressures on interaction traits, restricting the evolution of specialization.

Pollen diversity, viability and floral structure of some Musa genotypes

African Journals Online (AJOL)

Prof. Ogunji

Pollen diversity, viability and floral structure of some Musa genotypes ... at the Faculty of Agriculture & Natural Resources Management farm, Ebonyi State University,. Abakaliki. ..... Roots, tuber, plantains and bananas in human nutrition. Rome,.

Problemas na padronização da reação em cadeia da polimerase para diagnóstico da tuberculose pulmonar

Directory of Open Access Journals (Sweden)

Bollela Valdes R.

1999-01-01

Full Text Available OBJETIVO: Padronizar reação em cadeia da polimerase para diagnóstico de tuberculose pulmonar, comparando os resultados obtidos com as técnicas microbiológicas clássicas, e analisar seu uso numa região de alta prevalência da tuberculose. MÉTODOS: Foram descontaminadas, após a baciloscopia, 42 amostras de escarro de pacientes. Em seguida, procedeu-se ao cultivo em Lowenstein-Jensen e à reação em cadeia da polimerase com "primers" que amplificam um fragmento de 123 pares de base do genoma do Mycobacterium tuberculosis. RESULTADOS: Das 42 amostras de escarro, 10 apresentaram cultura positiva para M. tuberculosis. Dez foram positivas à baciloscopia e 16 mostraram-se positivas na reação em cadeia da polimerase. A sensibilidade e especificidade do teste em relação à cultura foi de 90% e 81%, respectivamente. CONCLUSÕES: A reação em cadeia da polimerase tem sensibilidade comparável à da cultura e pode ser realizada em apenas um dia, resultando em tratamento precoce e melhor controle da doença. A padronização e avaliação de técnicas de biologia molecular no diagnóstico da tuberculose no Brasil é imprescindível na discussão da implantação deste exame na rotina diagnóstica em centros de referência.

An ortholog of LEAFY in Jatropha curcas regulates flowering time and floral organ development.

Science.gov (United States)

Tang, Mingyong; Tao, Yan-Bin; Fu, Qiantang; Song, Yaling; Niu, Longjian; Xu, Zeng-Fu

2016-11-21

Jatropha curcas seeds are an excellent biofuel feedstock, but seed yields of Jatropha are limited by its poor flowering and fruiting ability. Thus, identifying genes controlling flowering is critical for genetic improvement of seed yield. We isolated the JcLFY, a Jatropha ortholog of Arabidopsis thaliana LEAFY (LFY), and identified JcLFY function by overexpressing it in Arabidopsis and Jatropha. JcLFY is expressed in Jatropha inflorescence buds, flower buds, and carpels, with highest expression in the early developmental stage of flower buds. JcLFY overexpression induced early flowering, solitary flowers, and terminal flowers in Arabidopsis, and also rescued the delayed flowering phenotype of lfy-15, a LFY loss-of-function Arabidopsis mutant. Microarray and qPCR analysis revealed several flower identity and flower organ development genes were upregulated in JcLFY-overexpressing Arabidopsis. JcLFY overexpression in Jatropha also induced early flowering. Significant changes in inflorescence structure, floral organs, and fruit shape occurred in JcLFY co-suppressed plants in which expression of several flower identity and floral organ development genes were changed. This suggests JcLFY is involved in regulating flower identity, floral organ patterns, and fruit shape, although JcLFY function in Jatropha floral meristem determination is not as strong as that of Arabidopsis.

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum)

Science.gov (United States)

Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

2018-01-01

Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions. PMID:29367803

Expression of proteinase inhibitor II proteins during floral development in Solanum americanum.

Science.gov (United States)

Sin, Suk-Fong; Chye, Mee-Len

2004-10-01

The heterologous expression of serine proteinase inhibitor II (PIN2) proteins confers insect resistance in transgenic plants, but little is known of their endogenous roles. We have cloned two cDNAs encoding Solanum americanum PIN2 proteins, SaPIN2a and SaPIN2b. SaPIN2a is highly expressed in stem, particularly in the phloem, suggesting it could possibly regulate proteolysis in the sieve elements. When SaPIN2a was expressed in transgenic lettuce, we observed an inhibition of endogenous trypsin- and chymotrypsin-like activities. Here, we demonstrate that both SaPIN2a and SaPIN2b are expressed in floral tissues that are destined to undergo developmental programmed cell death (PCD), suggesting possible endogenous roles in inhibiting trypsin- and chymotrypsin-like activities during flower development. Northern and western blot analyses revealed that SaPIN2a and SaPIN2b mRNAs and proteins show highest expression early in floral development. In situ hybridization analysis and immunolocalization on floral sections, localized SaPIN2a and SaPIN2b mRNAs and their proteins to tissues that would apparently undergo PCD: the ovules, the stylar transmitting tissue, the stigma and the vascular bundles. Detection of PCD in floral sections was achieved using terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) analysis. Examination of the mid-style before, and 1 day after, pollination revealed that high expression of SaPIN2a and SaPIN2b in the style was inversely correlated with PCD.

Biologia do jundiá Rhamdia quelen (Teleostei, Pimelodidae Biology of Rhamdia quelen (Teleostei, Pemelodidae

Directory of Open Access Journals (Sweden)

Levy de Carvalho Gomes

2000-03-01

Full Text Available O jundiá, Rhamdia quelen, é encontrado desde o centro da Argentina até o sul do México, e seu cultivo está aumentando no sul do Brasil. Portanto, o objetivo desta revisão é apresentar os dados existentes até o momento sobre a biologia dessa espécie. R. quelen pode atingir 50cm de comprimento e 3kg de peso, possui hábito noturno e habita locais calmos e profundos dos rios. Os alevinos suportam água do mar a 10%o, até 9,0g/l de sal comum e pH na faixa de 4,0 a 8,5, com melhor crescimento das larvas na faixa de pH de 8,0 a 8,5. É uma espécie euritérmica. Esse peixe é omnívoro, com tendência piscívora. A maturidade sexual é atingida no primeiro ano de vida. É uma espécie ovulípara e, na natureza, os cardumes desovam em locais com água limpa, calma e de fundo pedregoso. Não apresenta cuidado parental. Possui dois picos reprodutivos por ano (um no verão e outro na primavera e desova múltipla. A indução da desova apresentou bons resultados com gonadotrofina coriônica humana (HCG ou extrato hipofisário. O desenvolvimento embrionário de R. quelen é rápido e se dá entre 3 a 5 dias. O melhor alimento artificial para larvas de R. quelen é baseado em lecitina de soja, fígado bovino e levedura. Várias bactérias patogênicas e trematódeos digenéticos já foram identificados em R. quelen. Para um melhor aproveitamento dessa espécie na piscicultura, são necessários mais estudos relacionados ao efeito de parâmetros físicoquímicos da água, alimentação artificial e crescimento em cativeiro.The jundiá, Rhamdia quelen, occurs from Southern Mexico to Central Argentina, and the husbandry of this species is spreading in Southern Brazil. Consequently, the aim of this review is to present the available data of the biology of this species. R. quelen can reach 50cm of length and 3kg of weight, presents a nocturnal habit and lives in placid and deep waters of the rivers. Fingerlings support 10‰ seawater, up to 9g/l table

Legado Genético do Cromossoma Y . Caracterização do haplogrupo J em amostras de origem portuguesa com foco na zona centro

OpenAIRE

Albuquerque, Joana Isabel Silva de

2014-01-01

Dissertação de mestrado em Evolução e Biologia Humanas, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra Portugal revela um particular interesse na análise genética de populações modernas devido à complexidade da sua história nos últimos dois milénios, que envolveu uma estadia a longo prazo de populações bastante distintas ao nível da sua origem geográfica, religião e cultura. O grande contributo para o legado genético portugu...

36 CFR 12.10 - Floral and commemorative tributes.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Floral and commemorative tributes. 12.10 Section 12.10 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... of fresh cut or artificial flowers in or on a metal or other non-breakable rod or container...

Geographic variation in floral allometry suggests repeated transitions between selfing and outcrossing in a mixed mating plant.

Science.gov (United States)

Summers, Holly E; Hartwick, Sally M; Raguso, Robert A

2015-05-01

Isometric and allometric scaling of a conserved floral plan could provide a parsimonious mechanism for rapid and reversible transitions between breeding systems. This scaling may occur during transitions between predominant autogamy and xenogamy, contributing to the maintenance of a stable mixed mating system. We compared nine disjunct populations of the polytypic, mixed mating species Oenothera flava (Onagraceae) to two parapatric relatives, the obligately xenogamous species O. acutissima and the mixed mating species O. triloba. We compared floral morphology of all taxa using principal component analysis (PCA) and developmental trajectories of floral organs using ANCOVA homogeneity of slopes. The PCA revealed both isometric and allometric scaling of a conserved floral plan. Three principal components (PCs) explained 92.5% of the variation in the three species. PC1 predominantly loaded on measures of floral size and accounts for 36% of the variation. PC2 accounted for 35% of the variation, predominantly in traits that influence pollinator handling. PC3 accounted for 22% of the variation, primarily in anther-stigma distance (herkogamy). During O. flava subsp. taraxacoides development, style elongation was accelerated relative to anthers, resulting in positive herkogamy. During O. flava subsp. flava development, style elongation was decelerated, resulting in zero or negative herkogamy. Of the two populations with intermediate morphology, style elongation was accelerated in one population and decelerated in the other. Isometric and allometric scaling of floral organs in North American Oenothera section Lavauxia drive variation in breeding system. Multiple developmental paths to intermediate phenotypes support the likelihood of multiple mating system transitions. © 2015 Botanical Society of America, Inc.

Interações planta/beija-flor em tres comunidades vegetais da parte sul do Parque Nacional Natural Chiribiquete, Amazonas (Colombia)

OpenAIRE

Liliana Rosero Lasprila

2003-01-01

Resumo: Na parte sul do Parque Nacional Natural Chiribiquete, foram estudadas as interações planta/beija-flor em três comunidades vegetais diferenciadas em estrutura e composição florística: bosque de terra firme, bosque baixo das formações rochosas do Tepuy e bosque de "colúvio", que é transicional entre as duas anteriores comunidades. Foi determinada a composição florística das plantas ornitófilas, os atributos florais, fenologia da floração e oferta do recurso floral ao longo do ano nas tr...

Floral development and evolution of capitulum structure in Anacyclus (Anthemideae, Asteraceae).

Science.gov (United States)

Bello, M Angélica; Álvarez, Inés; Torices, Rubén; Fuertes-Aguilar, Javier

2013-11-01

Most of the diversity in the pseudanthia of Asteraceae is based on the differential symmetry and sexuality of its flowers. In Anacyclus, where there are (1) homogamous capitula, with bisexual, mainly actinomorphic and pentamerous flowers; and (2) heterogamous capitula, with peripheral zygomorphic, trimerous and long-/short-rayed female flowers, the floral ontogeny was investigated to infer their origin. Floral morphology and ontogeny were studied using scanning electron microscope and light microscope techniques. Disc flowers, subtended by paleae, initiate acropetally. Perianth and androecium initiation is unidirectional/simultaneous. Late zygomorphy occurs by enlargement of the adaxial perianth lobes. In contrast, ray flowers, subtended by involucral bracts, initiate after the proximal disc buds, breaking the inflorescence acropetal pattern. Early zygomorphy is manifested through the fusion of the lateral and abaxial perianth lobes and the arrest of the adaxials. We report atypical phenotypes with peripheral 'trumpet' flowers from natural populations. The peripheral 'trumpet' buds initiate after disc flowers, but maintain an actinomorphic perianth. All phenotypes are compared and interpreted in the context of alternative scenarios for the origin of the capitulum and the perianth identity. Homogamous inflorescences display a uniform floral morphology and development, whereas the peripheral buds in heterogamous capitula display remarkable plasticity. Disc and ray flowers follow different floral developmental pathways. Peripheral zygomorphic flowers initiate after the proximal actinomorphic disc flowers, behaving as lateral independent units of the pseudanthial disc from inception. The perianth and the androecium are the most variable whorls across the different types of flowers, but their changes are not correlated. Lack of homology between hypanthial appendages and a calyx, and the perianth double-sided structure are discussed for Anacyclus together with potential

Geographic variation in floral traits and the capacity of autonomous selfing across allopatric and sympatric populations of two closely related Centaurium species.

Science.gov (United States)

Schouppe, Dorien; Brys, Rein; Vallejo-Marin, Mario; Jacquemyn, Hans

2017-04-21

Floral traits and the relative contribution of autonomous selfing to total seed set varies geographically and is often driven by the availability and abundance of suitable pollinators and/or the presence of co-flowering relatives. In the latter case, competition for pollinator services and costs of hybridization can select for floral traits that reduce interspecific gene flow and contribute to prezygotic isolation, potentially leading to geographic variation in floral divergence between allopatric and sympatric populations. In this study, we investigated variation in floral traits and its implications on the capacity of autonomous selfing in both allopatric and sympatric populations of two closely related Centaurium species(Gentianaceae) across two distinct geographic regions(UK and mainland Europe). Although the magnitude and direction of floral differentiation varied between regions, sympatric populations were always significantly more divergent in floral traits and the capacity to self autonomously than allopatric populations. These results indicate that mating systems can vary substantially within a species and that the joint occurrence of plant species can have a major impact on floral morphology and capacity of autonomous selfing, most likely as a way to reduce the probability of interspecific interference.

A genetic screen for modifiers of UFO meristem activity identifies three novel FUSED FLORAL ORGANS genes required for early flower development in Arabidopsis.

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Levin, J Z; Fletcher, J C; Chen, X; Meyerowitz, E M

1998-06-01

In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s) acting between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development.

Covariance and decoupling of floral and vegetative traits in nine Neotropical plants: a re-evaluation of Berg's correlation-pleiades concept.

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Armbruster, W S; Di Stilio, V S; Tuxill, J D; Flores, T C; Velásquez Runk, J L

1999-01-01

Nearly forty years ago R. L. Berg proposed that plants with specialized pollination ecology evolve genetic and developmental systems that decouple floral morphology from phenotypic variation in vegetative traits. These species evolve separate floral and vegetative trait clusters, or as she termed them, "correlation pleiades." The predictions of this hypothesis have been generally supported, but only a small sample of temperate-zone herb and grass species has been tested. To further evaluate this hypothesis, especially its applicability to plants of other growth forms, we examined the patterns of phenotypic variation and covariation of floral and vegetative traits in nine species of Neotropical plants. We recognized seven specific predictions of Berg's hypothesis. Our results supported some predictions but not others. Species with specialized pollination systems usually had floral traits decoupled (weak correlation; Canna and Eichornia) or buffered (relationship with shallow proportional slope; Calathea and Canna) from variation in vegetative traits. However, the same trend was also observed in three species with unspecialized pollination systems (Echinodorus, Muntingia, and Wedelia). One species with unspecialized pollination (Croton) and one wind-pollinated species (Cyperus) showed no decoupling or buffering, as predicted. While species with specialized pollination usually showed lower coefficients of variation for floral traits than vegetative traits (as predicted), the same was also true of species with unspecialized or wind pollination (unlike our prediction). Species with specialized pollination showed less variation in floral traits than did species with unspecialized or wind pollination, as predicted. However, the same was true of the corresponding vegetative traits, which was unexpected. Also in contrast to our prediction, plants with specialized pollination systems did not exhibit tighter phenotypic integration of floral characters than did species with

Floral development and vascularization help to explain merism evolution in Paepalanthus (Eriocaulaceae, Poales

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Arthur de Lima Silva

2016-12-01

Full Text Available Background Flowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur in Paepalanthus and a few other genera. The floral merism in an evolutionary context, however, is unclear. Paepalanthus encompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative studies of infrageneric groups in Paepalanthus and in Eriocaulaceae are lacking, albeit necessary to establish evolution of characters such as floral merism and their role as putative synapomorphies. Methods We studied the floral development and vascularization of eight species of Paepalanthus that belong to distinct clades in which dimery occurs, using light and scanning electron microscopies. Results Floral ontogeny in dimerous Paepalanthus shows lateral sepals emerging simultaneously and late-developing petals. The outer whorl of stamens is absent in all flowers examined here. The inner whorl of stamens becomes functional in staminate flowers and is reduced to staminodes in the pistillate ones. In pistillate flowers, vascular bundles reach the staminodes. Ovary vascularization shows ventral bundles in a commissural position reaching the synascidiate portion of the carpels. Three gynoecial patterns are described for the studied species: (1 gynoecium with a short style, two nectariferous branches and two long stigmatic branches, in most species; (2 gynoecium with a long style, two nectariferous branches and two short stigmatic branches, in P. echinoides; and (3 gynoecium with long style, absent nectariferous branches and two short stigmatic branches, in P. scleranthus. Discussion Floral development of the studied species corroborates the hypothesis that the sepals of dimerous flowers of Paepalanthus correspond to the lateral sepals of trimerous flowers. The position and vascularization of floral parts also show that, during dimery evolution in Paepalanthus

Flavonoids patterns of French honeys with different floral origin

NARCIS (Netherlands)

Soler, C.; Gil, M.I.; Garcia-Viguera, C.; Tomás-Barberán, F.A.

1995-01-01

The flavonoid profiles of 12 different unifloral French honey samples were analysed by HPLC to evaluate if these substances could be used as markers of the floral origin of honey. In this analysis, the characteristic flavonoids from propolis and/or beeswax (chrysin, galangin, tectochrysin,

[Floral syndrome and breeding system of Corydalis edulis].

Science.gov (United States)

Xia, Qing; Zhou, Shoubiao; Zhang, Dong; Chao, Tiancai

2012-05-01

A field investigation was conducted on the floral syndrome and breeding system of Corydalis edulis located in natural populations in campus of Anhui Normal University by out-crossing index, pollen-ovule ratio, artificial pollination and bagging experiment. The results showed that the plant was in bloom from March to May and flowering span among populations was 72 days. The flowering span for a raceme was 14-24 days. The life span of one single flower was approximately 5-10 days. Spatial positioning of stigma and anthers were spatially desperation on the day of anthesis. The filaments were shorter than the styles through pollen vitality and stigma receptivity experiments. A self-pollination breeding system was reflected by OCI 3, pollinators were required sometimes; A complex cross bred was indicated by P/O = 857.14, combined with the results of the bagging and artificial pollination experiment, the breeding system of C. edulis was mixed with self-pollination and outcrossing. The special floral structure and pests destroying may have a certain impact on seed-set rate.

Floral Trait Variations Among Wild Tobacco Populations Influence the Foraging Behavior of Hawkmoth Pollinators

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Alexander Haverkamp

2018-02-01

Full Text Available Most pollinators visit flowers in the search of nectar rewards. However, as the floral nectar can often not be directly detected by pollinators, many flower visitors use secondary metabolites such as odor- or taste-proxies to anticipate nectar quantity and quality. Plants might exploit these sensory inferences of the pollinator to increase their pollination rates without increasing their caloric investment into their floral rewards. Here we investigated the effects of natural variation in certain primary and secondary floral metabolites in three populations of the wild tobacco, Nicotiana attenuata, on the pollination behavior of the hawkmoth Manduca sexta. Although offering the same caloric value per flower, the plants of these populations differ in the compositions and concentrations of sugars within the nectar. Moreover, the flowers of these plants emitted highly contrasting levels of attractive floral volatiles (benzyl acetone, but did not differ in the amounts of defensive nectar metabolites (nicotine. In wind tunnel assays with M. sexta moths, plants from those populations that released the largest amount of benzyl acetone as well as those that had a higher ratio of nectar sucrose were more frequently visited and re-visited by the hawkmoth. High emissions of benzyl acetone additionally correlated with a higher time investment of the moths into individual flowers on each visit, leading to the largest foraging success of the moths on those flowers that were most strongly scented. We propose that it is the variation of flower metabolites and their detection by the pollinator rather than the actual caloric value of the nectar, which determines pollinator visitations to a certain flower population. Hence, plants could potentially create a specialist pollinator community by altering their floral signals, either by producing volatiles that pollinators prefer or by providing nectar sugars that pollinators are most sensitive to, while at the same

Translocation of heavy metals from soils into floral organs and rewards of Cucurbita pepo: Implications for plant reproductive fitness.

Science.gov (United States)

Xun, Erna; Zhang, Yanwen; Zhao, Jimin; Guo, Jixun

2017-11-01

Metals and metalloids in soil could be transferred into reproductive organs and floral rewards of hyperaccumulator plants and influence their reproductive success, yet little is known whether non-hyperaccumulator plants can translocate heavy metals from soil into their floral organs and rewards (i.e., nectar and pollen) and, if so, whether plant reproduction will be affected. In our studies, summer squash (Cucurbita pepo L. cv. Golden Apple) was exposed to heavy-metal treatments during bud stage to investigate the translocation of soil-supplemented zinc, copper, nickel and lead into its floral organs (pistil, anther and nectary) and rewards (nectar and pollen) as well as floral metal accumulation effects on its reproduction. The results showed that metals taken up by squash did translocate into its floral organs and rewards, although metal accumulation varied depending on different metal types and concentrations as well as floral organ/reward types. Mean foraging time of honey bees to each male and female flower of squash grown in metal-supplemented soils was shorter relative to that of plants grown in control soils, although the visitation rate of honeybees to both male and female flowers was not affected by metal treatments. Pollen viability, pollen removal and deposition as well as mean mass per seed produced by metal-treated squash that received pollen from plants grown in control soils decreased with elevated soil-supplemented metal concentrations. The fact that squash could translocate soil-supplemented heavy metals into floral organs and rewards indicated possible reproductive consequences caused either directly (i.e., decreasing pollen viability or seed mass) or indirectly (i.e., affecting pollinators' visitation behavior to flowers) to plant fitness. Copyright © 2017 Elsevier Inc. All rights reserved.

[The Laboratório de Biologia Infantil, 1935-1941: from forensic medicine to social assistance].

Science.gov (United States)

Silva, Renato da

2011-12-01

This analysis of the history of the Laboratório de Biologia Infantil (Children's Biology Laboratory) discusses topics related to childhood and adolescence published in the Arquivos de Medicina Legal e Identificação do Rio de Janeiro. It underscores the political-institutional and intellectual contexts that prompted the 1930s debate about childhood among physicians, teachers, educators, and politicians, with a special focus on Leonídio Ribeiro, founder and first editor of the journal. The Laboratório inaugurated a medical and scientific routine for studying, treating, and providing assistance within institutions that had been created to repress, care for, and cure, and as such it represented an important chapter in the history of so-called abandoned and delinquent childhood.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

Science.gov (United States)

Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

2014-01-01

In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

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Stefan Dötterl

Full Text Available In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues in dioecious sallow, Salix caprea, ii to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Mediator subunit18 controls flowering time and floral organ identity in Arabidopsis.

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Zhengui Zheng

Full Text Available Mediator is a conserved multi-protein complex that plays an important role in regulating transcription by mediating interactions between transcriptional activator proteins and RNA polymerase II. Much evidence exists that Mediator plays a constitutive role in the transcription of all genes transcribed by RNA polymerase II. However, evidence is mounting that specific Mediator subunits may control the developmental regulation of specific subsets of RNA polymerase II-dependent genes. Although the Mediator complex has been extensively studied in yeast and mammals, only a few reports on Mediator function in flowering time control of plants, little is known about Mediator function in floral organ identity. Here we show that in Arabidopsis thaliana, MEDIATOR SUBUNIT 18 (MED18 affects flowering time and floral organ formation through FLOWERING LOCUS C (FLC and AGAMOUS (AG. A MED18 loss-of-function mutant showed a remarkable syndrome of later flowering and altered floral organ number. We show that FLC and AG mRNA levels and AG expression patterns are altered in the mutant. Our results support parallels between the regulation of FLC and AG and demonstrate a developmental role for Mediator in plants.

Influencia del fotoperiodo en el desarrollo floral de plantas de Solidago chilensis, Aster ericoides ev. 'Monteeasino' y Solidago x luteus Influenee of photoperiod on floral development in plants of Solidago chilensis, Aster ericoides ev. 'Monteeasino' and Solidago x tuteus

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Flórez Roncancio Victor J.

1998-06-01

Full Text Available Solidago x luteus es un híbrido interespecífico entre Solidago ptarmicoides y Solidago canadensis. Este híbrido, Solidago chilensis y Aster ericoides cv. 'Montecasino' son las especies objeto del presente estudio. Son plantas típicas de días largos, las cuales crecen como rosetas en días cortos y son explotadas para flor de corte. Se observaron características vegetativas y reproductivas de estas especies en condiciones fotoperiódicas de 8h y 20h y, en Solidago x luteus, por su mejor performance en cuanto a la inducción floral, se realizaron estudios de comportamiento fotoperiódico del desarrollo desde el botón floral hasta antesis. En forma general, en las tres especies estudiadas, los fotoperíodos largos promueven inducción floral y aumento en el número de ramificaciones laterales y de hojas. En días cortos, las
plantas de Solidago chilensis permanecieron en roseta, en las de Solidago x luteus hubo inducción y antesis floral, en tanto que, en Aster ericoides, había plantas en roseta y plantas inducidas. La evidencia de que los días cortos aceleraban la antesis floral en plantas de Solidago x luteus, inducidas en
días largos, se fortaleció con el experimento de diferente duración en días cortos (5; 10 y 15 días; lo cual se confirmó en experimentos subsecuentes, en donde se comprobó que la planta responde a los fotoperíodos cortos (8h; 10h y 12h, acelerando la antesis y a los fotoperíodos largos (16h y 20h, retardándola y los fotoperiódos entre 12h y 16h (14h  estarían en una situación de transición entre días cortos y días largos, caracterizando, así, una respuesta cuantitativa con el aumento del fotoperíodo.
Solidago x luteus is a hybrid between Solidago ptarmicoides and Solidago canadensis. This hybrid, Solidago chilensis and Aster ericoides cv. 'Montecasino' are the subject of the present work. They are typically long-day plants which grow as rosettes in short days and are exploited as cut

Floral ontogeny of two Jatropha species (Euphorbiaceae s.s) and its systematic implications

International Nuclear Information System (INIS)

Liu, H.; Liao, J.

2015-01-01

Floral ontogeny of Jatropha multifida L. and Jatropha integerrima Jacq. (Euphorbiaceae) was studied using scanning electron microscopy (SEM). These two species possess unisexual male flowers and bisexual (with unfunctional staminodes) female flowers. In both male and female flowers, five sepal primordia arise in a 2/5 sequence on the periphery of the floral apex and initiate anticlockwise or clockwise in different floral buds. Five petal primordia initiate simultaneously alternate to sepals. Dicyclic stamens (obdiplostemony) arise in both male and female flowers. In J. multifida, five outer stamen primordia arise first simultaneously and then three inner stamens initiate simultaneously. However, in J. integerrima, ten stamen primordia arranged in two whorls initiate simultaneously. While the ovary is absent in the male flowers, in the female flowers, three carpel primordia appear simultaneously. With further development of the ovary the stamens degenerate in the female flowers, whereas in the male flowers, the stamens grow normally. Ancestral state reconstruction using MacClade indicates that stamen simultaneous vs. non-simultaneous initiation supports the phylogenetic analysis based on nuclear ribosomal DNA ITS sequence. (author)

Estructura de la cèl·lula (materials de suport a l'estudi) : grau en Biologia

OpenAIRE

Ponsoda Martí, Xavier Josep

2013-01-01

El documentforma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València. Teoria 1. Introducció Mètodes d'estudi en biologia cel·lular. Cèl·lula procariota i cèl·lula eucariota. Els virus, estructura i cicle vital. Organització de la cèl·lula procariota. Organització de la cèl·lula eucariota. La cèl·lula animal i vegetal. 2. La membrana plasmàtica Model de mosaic fluid. Components de les membranes. Receptors de m...

Cytological behaviour of floral organs and in silico characterization ...

Indian Academy of Sciences (India)

c Indian Academy of Sciences. RESEARCH ... have defects in number, size, shape and function. ... associated with 'floral bud distortion' in soybean. J. Genet. 95, 787–799] ... with different names, namely no podding syndrome in India, .... three independent runs. ... eluted from the agaros gel with sharp surgical blade without.

Pollination of Cypripedium plectrochilum (Orchidaceae) by Lasioglossum spp. (Halictidae): the roles of generalist attractants versus restrictive floral architecture.

Science.gov (United States)

Li, P; Luo, Y; Bernhardt, P; Kou, Y; Perner, H

2008-03-01

The pollination of Cypripedium plectrochilum Franch. was studied in the Huanglong Nature Reserve, Sichuan, China. Although large bees (Bombus, Apis), small bees (Ceratina, Lasioglossum), ants (Formica sp.), true flies (Diptera) and a butterfly were all found to visit the flowers, only small bees, including three Lasioglossum spp. (L. viridiclaucum, L. sichuanense and L. sp.; Halictidae) and one Ceratina sp., carried the flower's pollen and contacted the receptive stigma. Measurements of floral architecture showed that interior floral dimensions best fit the exterior dimensions of Lasioglossum spp., leading to the consistent deposition and stigmatic reception of dorsally-placed, pollen smears. The floral fragrance was dominated by one ketone, 3-methyl-Decen-2-one. The conversion rate of flowers into capsules in open (insect) pollinated flowers at the site was more than 38%. We conclude that, while pigmentation patterns and floral fragrance attracted a wide variety of insect foragers, canalization of interior floral dimensions ultimately determined the spectrum of potential pollinators in this generalist, food-mimic flower. A review of the literature showed that the specialised mode of pollination-by-deceit in C. plectrochilum, limiting pollinators to a narrow and closely related guild of 'dupes' is typical for other members of this genus.

How to be an attractive male: floral dimorphism and attractiveness to pollinators in a dioecious plant

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Waelti Marc O

2009-08-01

Full Text Available Abstract Background Sexual selection theory predicts that males are limited in their reproductive success by access to mates, whereas females are more limited by resources. In animal-pollinated plants, attraction of pollinators and successful pollination is crucial for reproductive success. In dioecious plant species, males should thus be selected to increase their attractiveness to pollinators by investing more than females in floral traits that enhance pollinator visitation. We tested the prediction of higher attractiveness of male flowers in the dioecious, moth-pollinated herb Silene latifolia, by investigating floral signals (floral display and fragrance and conducting behavioral experiments with the pollinator-moth, Hadena bicruris. Results As found in previous studies, male plants produced more but smaller flowers. Male flowers, however, emitted significantly larger amounts of scent than female flowers, especially of the pollinator-attracting compounds. In behavioral tests we showed that naïve pollinator-moths preferred male over female flowers, but this preference was only significant for male moths. Conclusion Our data suggest the evolution of dimorphic floral signals is shaped by sexual selection and pollinator preferences, causing sexual conflict in both plants and pollinators.

Uniformidade e diversidade no ensino da física básica: os cursos de física para biologia, desenho industrial e farmácia

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Coelho L.F.S.

2002-01-01

Full Text Available O ensino universitário de Física atinge uma ampla faixa de carreiras. Ele é tradicionalmente dicotômico: enquanto carreiras na área técnico-científica recebem um ensino uniformizado em quatro semestres e com encadeamento formal baseado no Cálculo, as das áreas biomédica e da interface técnico-humana recebem um ensino diversificado por carreira e durando um ou dois semestres. Diversos fatores alteram este quadro, em particular o crescimento mundialmente intenso de áreas como a Genética, a Ecologia, a Farmácia e a Informática. No Brasil, temos também a tendência centrífuga no ensino uniformizado da área técnico-científica. Entre os argumentos para esse esvaziamento do curso unificado, respectivamente levantados pelas unidades de origem dos alunos e pelas de Física, estão a diversidade das necessidades futuras dos alunos e a heterogeneidade da sua formação prévia. O estudo do resultado na prova de Física dos alunos classificados no Vestibular da UFRJ para o período 1994-1997 evidencia que a heterogeneidade é enorme para o conjunto de carreiras, mas que é muito menor quando focamos apenas a Engenharia. Portanto, ambas as explicações para os problemas destes cursos de Física são muito parciais e este estudo da heterogeneidade sugere que causas mais fundamentais estão em ação: a formação prévia dos estudantes, o currículo universitário (carga horária e conteúdo das disciplinas e o vestibular são inadequados. Numa segunda parte deste trabalho, são apresentadas três experiências na UFRJ de disciplinas de Física para áreas não-técnico-científicas: Biologia, Desenho Industrial e Farmácia. Em resumo, estas disciplinas têm forte conteúdo fenomenológico e qualitativo e são apoiadas em exemplos físicos relevantes para cada área. Isso, em geral, requer tanto um percentual de Física Moderna superior ao usual nos cursos para as áreas técnico-científicas quanto a constante atualização desses

Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

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Liliana M Cano

Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.

Digital Gene Expression Analysis Based on De Novo Transcriptome Assembly Reveals New Genes Associated with Floral Organ Differentiation of the Orchid Plant Cymbidium ensifolium.

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Fengxi Yang

Full Text Available Cymbidium ensifolium belongs to the genus Cymbidium of the orchid family. Owing to its spectacular flower morphology, C. ensifolium has considerable ecological and cultural value. However, limited genetic data is available for this non-model plant, and the molecular mechanism underlying floral organ identity is still poorly understood. In this study, we characterize the floral transcriptome of C. ensifolium and present, for the first time, extensive sequence and transcript abundance data of individual floral organs. After sequencing, over 10 Gb clean sequence data were generated and assembled into 111,892 unigenes with an average length of 932.03 base pairs, including 1,227 clusters and 110,665 singletons. Assembled sequences were annotated with gene descriptions, gene ontology, clusters of orthologous group terms, the Kyoto Encyclopedia of Genes and Genomes, and the plant transcription factor database. From these annotations, 131 flowering-associated unigenes, 61 CONSTANS-LIKE (COL unigenes and 90 floral homeotic genes were identified. In addition, four digital gene expression libraries were constructed for the sepal, petal, labellum and gynostemium, and 1,058 genes corresponding to individual floral organ development were identified. Among them, eight MADS-box genes were further investigated by full-length cDNA sequence analysis and expression validation, which revealed two APETALA1/AGL9-like MADS-box genes preferentially expressed in the sepal and petal, two AGAMOUS-like genes particularly restricted to the gynostemium, and four DEF-like genes distinctively expressed in different floral organs. The spatial expression of these genes varied distinctly in different floral mutant corresponding to different floral morphogenesis, which validated the specialized roles of them in floral patterning and further supported the effectiveness of our in silico analysis. This dataset generated in our study provides new insights into the molecular mechanisms

Desenvolvimento e exigências térmicas de Trichogramma pretiosum Riley, criados em duas traças do tomateiro

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PRATISSOLI DIRCEU

2000-01-01

Full Text Available Estudou-se a biologia de Trichogramma pretiosum em ovos de Phthorimaea operculella (Zeller e Tuta absoluta (Meyrick em diferentes temperaturas (18, 20, 22, 25, 30 e 32ºC, 70±10% de umidade relativa e fotofase de 14 horas, com o objetivo de se determinarem as exigências térmicas, bem como o número de gerações durante o ano. Houve correlação inversa entre a duração do ciclo e o aumento de temperatura na faixa térmica estudada. A razão sexual, no entanto, não foi afetada pela temperatura quando o hospedeiro foi T. absoluta. A viabilidade de T. pretiosum, criado em P. operculella foi mais afetada que em T. absoluta. A exigência térmica, calculada pelo método da hipérbole, foi maior no tocante a T. absoluta (131,3 graus dia em relação a P. operculella (120,9 graus dia, e o limiar térmico inferior, respectivamente, 12,98 e 13,53°C. No que tange a ambas as espécies de traças, a longevidade do parasitóide sempre obedeceu à distribuição de Weibull. O potencial de aumento foi avaliado, em ambas as espécies de traças, com base no número de gerações anuais.

Direct and indirect effects of land use on floral resources and flower-visiting insects across an urban landscape

Science.gov (United States)

Matteson, K.C.; Grace, James B.; Minor, E.S.

2013-01-01

Although urban areas are often considered to have uniformly negative effects on biodiversity, cities are most accurately characterized as heterogeneous mosaics of buildings, streets, parks, and gardens that include both ‘good’ and ‘bad’ areas for wildlife. However, to date, few studies have evaluated how human impacts vary in direction and magnitude across a heterogeneous urban landscape. In this study, we assessed the distribution of floral resources and flower-visiting insects across a variety of land uses in New York City. We visited both green spaces (e.g. parks, cemeteries) and heavily developed neighborhood blocks (e.g. with high or low density residential zoning) and used structural equation modeling (SEM) to evaluate the direct and indirect effects of median income, vegetation, and development intensity on floral resources and insects in both settings. Abundance and taxonomic richness of flower-visiting insects was significantly greater in green spaces than neighborhood blocks. The SEM results indicated that heavily-developed neighborhoods generally had fewer flower-visiting insects consistent with reductions in floral resources. However, some low-density residential neighborhoods maintained high levels of floral resources and flower-visiting insects. We found that the effects of surrounding vegetation on floral resources, and thus indirect effects on insects, varied considerably between green spaces and neighborhood blocks. Along neighborhood blocks, vegetation consisted of a mosaic of open gardens and sparsely distributed trees and had a positive indirect effect on flower-visiting insects. In contrast, vegetation in urban green spaces was associated with increased canopy cover and thus had a negative indirect effect on flower-visiting insects through reductions in floral resources. In both neighborhood blocks and green spaces, vegetation had a positive direct effect on flower-visiting insects independent of the influence of vegetation on floral

Produtividade e qualidade de abacaxizeiro cv. Smooth Cayenne, cultivado comaplicação de doses e parcelamentos do nitrogênio, em Guaraçaí-SP Productivity and quality of pineapple cv. Smooth Cayenne, cultivated with nitrogen doses and splitting application in Guaraçaí-SP

Directory of Open Access Journals (Sweden)

Leandro Spegiorin Marques

2011-09-01

Full Text Available A adubação é um dos fatores que influem na produção e qualidade dos frutos; portanto, a necessidade de se estudar o efeito do nitrogênio aplicado antes e após a indução floral nestas características dos frutos de abacaxi é fundamental. Os objetivos deste trabalho foram avaliar a produtividade, o estado nutricional e os aspectos quantitativos e qualitativos dos frutos de abacaxizeiro 'Smooth Cayenne' submetidos a doses e parcelamentos do nitrogênio, cultivado em Guaraçaí-SP. O delineamento experimental adotado foi o de blocos ao caso, com quatro repetições e dezesseis tratamentos, num esquema fatorial 4x4, sendo quatro doses de N: 7,5; 15; 22,5 e 30 g planta-1 de N, e quatro parcelamentos: toda a dose aplicada antes da indução floral, metade da dose antes da indução floral e a outra metade após a indução, 2/3 da dose antes da indução e 1/3 da dose após a indução e toda a dose após a indução floral. A aplicação total do N após a indução floral, independentemente da dose, resultou em menores teores foliares de N e dimensões da folha "D", apresentando na colheita frutos pequenos, com menor índice de maturação e maior acidez. Para obtenção de frutos de abacaxi cv. Smooth Cayenne, com maior tamanho, massa e maior teor de SST e menor acidez, a adubação nitrogenada pode ser aplicada em dose total, antes da indução floral, ou parcelada 2/3 antes e 1/3 após esta indução. A adubação nitrogenada incrementou os teores foliares de N, entretanto não teve efeito nas dimensões, produtividade e qualidade de frutos de abacaxizeiro cv. Smooth Cayenne.Fertilization is one of the factors that influence the production and fruit quality, thus the need to study the nitrogen effect applied before and after the floral induction in pineapple fruit characteristics is fundamental. The aim of this study was to evaluate the productivity, nutritional status and the quantitative and qualitative aspects of pineapple fruits

Drought and increased CO2 alter floral visual and olfactory traits with context-dependent effects on pollinator visitation

Science.gov (United States)

William R. Glenny; Justin B. Runyon; Laura A. Burkle

2018-01-01

Climate change can alter species interactions essential for maintaining biodiversity and ecosystem function, such as pollination. Understanding the interactive effects of multiple abiotic conditions on floral traits and pollinator visitation are important to anticipate the implications of climate change on pollinator services. Floral visual and olfactory traits were...

Caffeine in floral nectar enhances a pollinator’s memory of reward

Science.gov (United States)

Wright, G. A.; Baker, D. D.; Palmer, M. J.; Stabler, D.; Mustard, J. A.; Power, E. F.; Borland, A. M.; Stevenson, P. C.

2015-01-01

Plant defence compounds occur in floral nectar, but their ecological role is not well-understood. We provide the first evidence that plant compounds pharmacologically alter pollinator behaviour by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times more likely to remember a learned floral scent than those rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar never exceeded the bees’ bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success. PMID:23471406

Biological parameters of the non-target pest Aphis gossypii Glover ...

African Journals Online (AJOL)

Thiago Mota

2013-04-17

Apr 17, 2013 ... Development and commercial use of Bollgard cotton in the USA nearly promises versus today reality. Plant. J. 27:489-501. Pessoa LGA, Souza B, Carvalho CF, Silva M (2004). Aspectos da biologia de Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) em quatro cultivares de Algodoeiro, em Laboratório.

Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: implications for flower visitation by bees

Science.gov (United States)

Rodriguez-Saona, Cesar; Parra, Leonardo; Quiroz, Andrés; Isaacs, Rufus

2011-01-01

Background and Aims Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined. Methods Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles. Key Results Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps. Conclusions Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in

Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: implications for flower visitation by bees.

Science.gov (United States)

Rodriguez-Saona, Cesar; Parra, Leonardo; Quiroz, Andrés; Isaacs, Rufus

2011-06-01

Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined. Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles. Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps. Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in increasing pollination of flowers.

Research on floral timing by ambient temperature comes into blossom

NARCIS (Netherlands)

Verhage, D.S.L.; Angenent, G.C.; Immink, R.G.H.

2014-01-01

The floral transition is an essential process in the life cycle of flower-bearing plants, because their reproductive success depends on it. To determine the right moment of flowering, plants respond to many environmental signals, including day length, light quality, and temperature. Small changes in

High floral bud abscission and lack of open flower abscission in Dendrobium cv. Miss Teen: rapid reduction of ethylene sensitivity in the abscission zone

NARCIS (Netherlands)

Bunya-atichart, K.; Ketsa, S.; Doorn, van W.G.

2006-01-01

We studied the abscission of floral buds and open flowers in cut Dendrobium inflorescences. Abscission of floral buds was high and sensitive to ethylene in all cultivars studied. Many open flowers abscised in most cultivars, but cv. Willie exhibited only small amount of floral fall and cv. Miss Teen

Pollinarium morphology and floral rewards in Brazilian Maxillariinae (Orchidaceae).

Science.gov (United States)

Singer, Rodrigo B; Koehler, Samantha

2004-01-01

There is strong support for the monophyly of the orchid subtribe Maxillariinae s.l., yet generic boundaries within it are unsatisfactory and need re-evaluation. In an effort to assemble sets of morphological characters to distinguish major clades within this subtribe, the pollinarium morphology and floral rewards of representative Brazilian species of this subtribe were studied. The study was based on fresh material from 60 species and seven genera obtained from cultivated specimens. Variation of pollinarium structure and floral rewards was assessed using a stereomicroscope and by SEM analysis. Four morphological types of pollinaria are described. Type 1 appears to be the most widespread and is characterized by a well-developed tegula. Type 2 lacks a stipe and the pollinia are attached directly to the viscidium. Type 3 also lacks a stipe, and the viscidium is rigid and dark. In Type 4, the stipe consists of the whole median rostelar portion and, so far, is known only from Maxillaria uncata. Nectar, trichomes, wax-like and resin-like secretions are described as flower rewards for different groups of species within the genus Maxillaria. Data on the biomechanics and pollination biology are also discussed and illustrated. In Maxillariinae flowers with arcuate viscidia, the pollinaria are deposited on the scuttellum of their Hymenopteran pollinators. In contrast, some flowers with rounded to rectangular, pad-like viscidia fix their pollinaria on the face of their pollinators. Pollinarium morphology and floral features related to pollination in Brazilian Maxillariinae are more diverse than previously suggested. It is hoped that the data presented herein, together with other data sources such as vegetative traits and molecular tools, will be helpful in redefining and diagnosing clades within the subtribe Maxillariinae.

Apresentação da XI Expedição Científica do Departamento de Biologia : GRACIOSA 2004.

OpenAIRE

Tavares, João

2005-01-01

XI Expedição Científica do Departamento de Biologia - Graciosa 2004. A Ilha Graciosa foi escolhida para a realização desta expedição científica por vários motivos e com diferentes objectivos, entre os quais salientamos: a sua situação geográfica; o seu reduzido tamanho; o grandioso e importante número de ilhéus que a rodeiam; os diversificados ecossistemas que a compõem. Neste projecto foi dada prioridade à zona costeira, que é sem dúvida uma verdadeira fronteira entre o mundo terrestre...

The early inflorescence of Arabidopsis thaliana demonstrates positional effects in floral organ growth and meristem patterning.

Science.gov (United States)

Plackett, Andrew R G; Powers, Stephen J; Phillips, Andy L; Wilson, Zoe A; Hedden, Peter; Thomas, Stephen G

2018-06-01

Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradicted by the existence of mutants with phenotypes visible in early flowers only. This phenomenon is demonstrated by mutants partially impaired in the biosynthesis of the phytohormone gibberellin (GA), in which floral organ growth is retarded in the first flowers to be produced but has recovered spontaneously by the 10th flower. We presently lack systematic data from multiple flowers across the Arabidopsis inflorescence to explain such changes. Using mutants of the GA 20-OXIDASE (GA20ox) GA biosynthesis gene family to manipulate endogenous GA levels, we investigated the dynamics of changing floral organ growth across the early Arabidopsis inflorescence (flowers 1-10). Modelling of floral organ lengths identified a significant, GA-independent gradient of increasing stamen length relative to the pistil in the wild-type inflorescence that was separable from other, GA-dependent effects. It was also found that the first flowers exhibited unstable organ patterning in contrast to later flowers and that this instability was prolonged by exogenous GA treatment. These findings indicate that the development of individual flowers is influenced by hitherto unknown factors acting across the inflorescence and also suggest novel functions for GA in floral patterning.

Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops

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LC Rodrigues

Full Text Available Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops.

Science.gov (United States)

Rodrigues, L C; Rodrigues, M

2015-01-01

Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

Avaliação de antibiose e não-preferência em cultivares de milho selecionados com resistência à lagarta-do-cartucho

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VIANA PAULO AFONSO

2000-01-01

Full Text Available Dentre os fatores que contribuem para reduzir a produtividade das lavouras de milho estão as pragas, destacando-se a lagarta-do-cartucho, Spodoptera frugiperda, a qual pode reduzir a produção em até 34%. Um dos métodos de controle de pragas, cujo custo é reduzido e não causa efeitos indesejáveis ao ambiente, é o desenvolvimento de cultivares resistentes. Diversas fontes de resistência foram identificadas, linhagens desenvolvidas, registradas e liberadas ao público; entretanto, pouca informação tem sido veiculada a respeito dos mecanismos e causas dessa resistência. O objetivo do presente trabalho foi estudar os mecanismos de resistência, não-preferência e antibiose em genótipos de milho selecionados, com resistência a S. frugiperda. Os ensaios foram conduzidos em laboratório e em casa de vegetação da EMBRAPA/CNPMS. O genótipo CMS 14C apresentou antibiose influindo negativamente na biologia de S. frugiperda. 'CMS 24' e 'CMS 23' apresentaram também esse mecanismo, porém em menor intensidade. Foi constatada não-preferência alimentar das lagartas para 'Zapalote Chico' e 'BR 201'. Não-preferência para oviposição foi constatada em 'CMS 14C' e 'Zapalote Chico'.

Saúde e antropologia: contribuições à interpretação da condição humana em ciências da saúde

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Tullio Seppilli

Full Text Available A interpretação do processo saúde/doença tem sido marcada pelo positivismo e pelas ciências naturais. A medicina/saúde ocidental concentrou uma atenção quase exclusiva às dimensões biológicas das patologias, demarcando sucessos cognitivos e operacionais, a biologia representando a verdadeira prova de rigor e objetividade. A função moduladora em relação às defesas orgânicas era atuada pelas dinâmicas psíquicas, a dimensão da subjetividade como lugar da ativa intermediação, em cada indivíduo, entre as esferas relacional e biológica. O reconhecimento dos fatores comportamentais e socioculturais desenvolveu-se fora do campo médico-institucional, seguindo linhas de investigação das disciplinas psicológicas e antropológicas. O texto tenta esboçar que um efetivo delineamento científico dos estudos sobre o homem somente pode fundar-se em uma abordagem sistêmica, em que os níveis biológico e histórico-social, que organizam a condição humana e realizam sua relação com o contexto, precisam ser examinados e interpretados em suas relações de integração, em sua recíproca autonomia e especificidade.

Saúde e antropologia: contribuições à interpretação da condição humana em ciências da saúde

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Tullio Seppilli

2011-09-01

Full Text Available A interpretação do processo saúde/doença tem sido marcada pelo positivismo e pelas ciências naturais. A medicina/saúde ocidental concentrou uma atenção quase exclusiva às dimensões biológicas das patologias, demarcando sucessos cognitivos e operacionais, a biologia representando a verdadeira prova de rigor e objetividade. A função moduladora em relação às defesas orgânicas era atuada pelas dinâmicas psíquicas, a dimensão da subjetividade como lugar da ativa intermediação, em cada indivíduo, entre as esferas relacional e biológica. O reconhecimento dos fatores comportamentais e socioculturais desenvolveu-se fora do campo médico-institucional, seguindo linhas de investigação das disciplinas psicológicas e antropológicas. O texto tenta esboçar que um efetivo delineamento científico dos estudos sobre o homem somente pode fundar-se em uma abordagem sistêmica, em que os níveis biológico e histórico-social, que organizam a condição humana e realizam sua relação com o contexto, precisam ser examinados e interpretados em suas relações de integração, em sua recíproca autonomia e especificidade.

Effect of floral display on reproductive success in terrestrial orchids

Czech Academy of Sciences Publication Activity Database

Kindlmann, Pavel; Jersáková, Jana

2006-01-01

Roč. 41, - (2006), s. 47-60 ISSN 0015-5551 R&D Projects: GA AV ČR(CZ) KJB6141302; GA ČR(CZ) GA206/00/1124 Keywords : deceptivity * floral display * orchid * reproductive success * reward Subject RIV: EF - Botanics Impact factor: 1.033, year: 2005

Floral biology and the effects of plant-pollinator interaction on ...

African Journals Online (AJOL)

Reproductive biology and patterns of plant-pollinator interaction are fundamental to gene flow, diversity and evolutionary success of plants. Consequently, we examined the magnitude of insect-plant interaction based on the dynamics of breeding systems and floral biology and their effects on pollination intensity, fruit and ...

Insect-flower interaction network structure is resilient to a temporary pulse of floral resources from invasive Rhododendron ponticum.

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Erin Jo Tiedeken

Full Text Available Invasive alien plants can compete with native plants for resources, and may ultimately decrease native plant diversity and/or abundance in invaded sites. This could have consequences for native mutualistic interactions, such as pollination. Although invasive plants often become highly connected in plant-pollinator interaction networks, in temperate climates they usually only flower for part of the season. Unless sufficient alternative plants flower outside this period, whole-season floral resources may be reduced by invasion. We hypothesized that the cessation of flowering of a dominant invasive plant would lead to dramatic, seasonal compositional changes in plant-pollinator communities, and subsequent changes in network structure. We investigated variation in floral resources, flower-visiting insect communities, and interaction networks during and after the flowering of invasive Rhododendron ponticum in four invaded Irish woodland sites. Floral resources decreased significantly after R. ponticum flowering, but the magnitude of the decrease varied among sites. Neither insect abundance nor richness varied between the two periods (during and after R. ponticum flowering, yet insect community composition was distinct, mostly due to a significant reduction in Bombus abundance after flowering. During flowering R. ponticum was frequently visited by Bombus; after flowering, these highly mobile pollinators presumably left to find alternative floral resources. Despite compositional changes, however, network structural properties remained stable after R. ponticum flowering ceased: generality increased, but quantitative connectance, interaction evenness, vulnerability, H'2 and network size did not change. This is likely because after R. ponticum flowering, two to three alternative plant species became prominent in networks and insects increased their diet breadth, as indicated by the increase in network-level generality. We conclude that network structure

Voltammetric sensor for electrochemical determination of the floral origin of honey based on a zinc oxide nanoparticle modified carbon paste electrode

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K. Tiwari

2018-04-01

Full Text Available A new methodology based on cyclic voltammetry using a chemically modified electrode has been developed for the discrimination of the floral origin of honey. This method involves an electronic tongue with an electrochemical sensor made from a carbon paste (CPs electrode where zinc oxide (ZnO nanoparticles are used as an electroactive binder material. The bare CPs electrode is evaluated for comparison. The electrochemical response of the modified electrode in 50 samples of five different floral types of honey has been analysed by the cyclic voltammetric technique. The voltammograms of each floral variety of honey reflect the redox properties of the ZnO nanoparticles present inside the carbon paste matrix and are strongly influenced by the nectar source of honey. Thus, each type of honey provides a characteristic signal which is evaluated by using principal component analysis (PCA and an artificial neural network (ANN. The result of a PCA score plot of the transient responses obtained from the modified carbon paste electrode clearly shows discrimination among the different floral types of honey. The ANN model for floral classification of honey shows more than 90 % accuracy. These results indicate that the ZnO nanoparticles modified carbon paste (ZnO Nps modified CPs electrode can be a useful electrode for discrimination of honey samples from different floral origins.

Selection by pollinators on floral traits in generalized Trollius ranunculoides (Ranunculaceae along altitudinal gradients.

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Zhi-Gang Zhao

Full Text Available Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral differentiation. We investigated the variation of Trollius ranunculoides flowers and its pollinators along an altitudinal gradient on the eastern Qinghai-Tibet Plateau, and measured phenotypic selection by pollinators on floral traits across populations. The results showed significant decline of visitation rate of bees along altitudinal gradients, while flies was unchanged. When fitness is estimated by the visitation rate rather than the seed number per plant, phenotypic selection on the sepal length and width shows a significant correlation between the selection strength and the altitude, with stronger selection at higher altitudes. However, significant decreases in the sepal length and width of T. ranunculoides along the altitudinal gradient did not correspond to stronger selection of pollinators. In contrast to the pollinator visitation, mean annual precipitation negatively affected the sepal length and width, and contributed more to geographical variation in measured floral traits than the visitation rate of pollinators. Therefore, the sepal size may have been influenced by conflicting selection pressures from biotic and abiotic selective agents. This study supports the hypothesis that lower pollinator availability at high altitude can intensify selection on flower attractive traits, but abiotic selection is preventing a response to selection from pollinators.

CARACTERIZACIÓN DE LA MORFOLOGÍA FLORAL DE DOS CULTIVARES DE BERENJENA (Solanum melongena L. (Solanaceae FLORAL MORPHOLOGY CHARACTERIZATION OF TWO CULTIVARS OF EGGPLANT (Solanum melongena L. (Solanaceae

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Hermes Araméndiz Tatis

2009-12-01

Full Text Available La berenjena es una especie perteneciente al género Solanum, de gran importancia en la horticultura del Caribe colombiano. El estudio tuvo como objetivo describir la morfología floral de dos cultivares de berenjena “Long Purple” y “Criolla Lila”, que tienen origen geográfico diferente, utilizando para ello, una muestra aleatoria de 100 cojines florales por cultivar. Se estimaron la media, rango, varianza, desviación estándar, coeficiente de variación y se aplicó la prueba t, para determinar diferencias entre los dos cultivares. Los resultados indicaron que el cultivar “Long Purple”, presenta flores distílicas, en tanto que en el “Criollo Lila” se observó la presencia de tristilia. El potencial de producción de frutos, fue del 76,5% y 57,52%, para el “Criollo Lila” y “Long Purple”, respectivamente. Las flores brevistílicas en ambos cultivares, incrementan la aptitud masculina y por ende un desbalance entre las flores con funcionamiento masculino y hermafrodita.The eggplant is a specie of genus Solanum, of great importance in horticulture of colombian Caribbean region. The objective of study was to describe the floral morphology of two cultivars of eggplant “Long Purple” and “Lilac land race”, which have different geographic origin. We used a random sample of 100 floral cushions for cultivar. The mean, range, variance, standard deviation, variation coefficient were estimated. The t-test was applied to determine differences between two cultivars. The results indicated that genotype ‘Long Purple’, showed distylics flowers, while in the “Lilac land race” was observed the presence of tristylics flowers. The potential for production of fruit was 76.50% and 57.52% for the “Lilac land race” and “Long Purple”, respectively. Brevistylics flowers in the two cultivars, increased male fitness and thus produced a nonbalance on functioning between male and hermaphrodite flowers.

Post harvest of pink ginger floral stems treated with silver thiosulphate, sucrose, and calcium Pós-colheita de hastes de alpínia tratadas com tiossulfato de prata, sacarose e cálcio

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Antonio Tarciso C da Silva

2009-09-01

Full Text Available The Brazilian market of tropical flowers has been growing broadly with a strong participation of the Northeast Region, where the State of Alagoas stands out. Among the exporting tropical cut flowers, pink ginger (Alpinia purpurata (Vieill K. Schum has been one of the most promising species. Aiming at delaying senescence in floral stems of pink ginger, two laboratory experiments were carried out at the Agricultural Science Center of the Federal University of Alagoas. In the first experiment, three different exposure periods (30; 60, and 120 minutes to silver thiosulphate 1 mM were tested, followed or not by pulsing in a 20% sucrose solution, for 12 hours. In the second experiment, we evaluated the effect of adding calcium sulphate 50 and 100 mM, sodium silicate 1.25 and 2.5 mM, and the combination of calcium sulphate 50mM + sodium silicate 1.25mM on the hydric status and longevity of floral stems. In both experiments, the control treatment consisted of keeping stems in distilled water. Fresh biomass and quality of floral stems were determined every other day. Silver thiosulphate applied in pulsing for 60 minutes or more led to stem dehydration, whereas calcium sulphate improved both stem hydration and commercial durability.O mercado brasileiro de flores tropicais encontra-se em franco crescimento, com uma importante participação da região Nordeste, destacando-se o estado de Alagoas. Dentre as flores tropicais de corte para exportação, a alpínia (Alpiniapurpurata (Vieill K. Schum ocupa posição de destaque. Visando retardar a senescência das hastes florais de alpínia, cultivar Pink Ginger, foram conduzidos dois experimentos em laboratório no CCA da Universidade Federal de Alagoas. No primeiro, foram testados três tempos (30; 60 e 120 minutos de exposição ao tiossulfato de prata 1 mM, seguido ou não de pulsing em sacarose a 20%, por 12 horas. No segundo experimento foram verificados os efeitos nas relações hídricas e longevidade

Divulgação

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Equipe REB Ensino de Bioquímica

2015-06-01

Full Text Available A partir do 2015 faremos a divulgação de portais e materiais de ensino na área de Bioquímica, Biologia Molecular, Ciências, Biologia, Química e áreas correlatas.O objetivo é ampliar a divulgação e o acesso aos interessados visando a melhoria e a potencialização dos processos de aprendizagem.Caso tenha interesse em fazer a divulgação de seu material ou portal, escreva para contato@bioquimica.org.br indicando o título, resumo, instituição, responsável. Tempo de Ciências - PodCiência: podcasts de divulgação científicaPortal de divulgação científica por meio de podcasts nas áreas de Biologia e Química, desenvolvido no Instituto de Bioquímica Média Leopoldo de Meiswebsite: http://tempodeciencia.wix.com/site#!podcincia/c11nfFacebook: https://www.facebook.com/tempodeciencia Energia e Matéria - da fundamentação conceitual às aplicações tecnológicasLivro abordando a energia, matéria e suas transformações, abordando a temática de modo multidisciplinar, congregando a Biologia, Física e Química em uma obra que busca a integração dos conhecimentos na busca de novos caminhos para o ensino integrado e contextualizado, saindo da escala micro para a nanoscópica.1a Edição – 2015 – ISBN 9788578613280Carlos Alberto dos Santos (org, professor na Universidade Federal do Rio Grande do Sul B iblioteca Digital de CiênciasPortal que disponibiliza materiais (vídeos, áudios, textos, softwares, roteiros de aulas práticas na área de Biologia/ Ciênciias, Bioquímica e correlatas, desenvolvido no Laboratório de Tecnologias Educacionais (LTE, Instituto de Biologia, Unicamp.website:http://www.bdc.ib.unicamp.br

Drought and leaf herbivory influence floral volatiles and pollinator attraction

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Laura A. Burkle; Justin B. Runyon

2016-01-01

The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...

How to be sweet? Extra floral nectar allocation by Gossypium hirsutum fits optimal defense theory predictions

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Wäckers, F.L.; Bonifay, C.

2004-01-01

Plants employ nectar for two distinct functions. Floral nectar has traditionally been viewed in the context of pollination. Extrafloral nectar on the other hand, can act as an indirect defense, allowing the plant to recruit predators and parasitoids. Whereas this makes for a clear-cut categorization, in reality the functions may not be so discrete. Extrafloral nectar may serve a role in pollination, while floral nectar can be utilized by predators and parasitoids and thus can contribute to pl...

An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

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Eddy Risseeuw

Full Text Available Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

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Risseeuw, Eddy; Venglat, Prakash; Xiang, Daoquan; Komendant, Kristina; Daskalchuk, Tim; Babic, Vivijan; Crosby, William; Datla, Raju

2013-01-01

Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

Arabidopsis BLADE-ON-PETIOLE1 and 2 promote floral meristem fate and determinacy in a previously undefined pathway targeting APETALA1 and AGAMOUS-LIKE24.

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Xu, Mingli; Hu, Tieqiang; McKim, Sarah M; Murmu, Jhadeswar; Haughn, George W; Hepworth, Shelley R

2010-09-01

The transition to flowering is a tightly controlled developmental decision in plants. In Arabidopsis, LEAFY (LFY) and APETALA1 (AP1) are key regulators of this transition and expression of these genes in primordia produced by the inflorescence meristem confers floral fate. Here, we examine the role of architectural regulators BLADE-ON-PETIOLE1 (BOP1) and BOP2 in promotion of floral meristem identity. Loss-of-function bop1 bop2 mutants show subtle defects in inflorescence and floral architecture but in combination with lfy or ap1, synergistic defects in floral meristem fate and determinacy are revealed. The most dramatic changes occur in bop1 bop2 ap1-1 triple mutants where flowers are converted into highly branched inflorescence-like shoots. Our data show that BOP1/2 function distinctly from LFY to upregulate AP1 in floral primordia and that all three activities converge to down-regulate flowering-time regulators including AGAMOUS-LIKE24 in stage 2 floral meristems. Subsequently, BOP1/2 promote A-class floral-organ patterning in parallel with LFY and AP1. Genetic and biochemical evidence support the model that BOP1/2 are recruited to the promoter of AP1 through direct interactions with TGA bZIP transcription factors, including PERIANTHIA. These data reveal an important supporting role for BOP1/2 in remodeling shoot architecture during the floral transition. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

Evolution of floral symmetry Peter K Endress, Current Opinion in ...

Indian Academy of Sciences (India)

First page Back Continue Last page Graphics. Evolution of floral symmetry Peter K Endress, Current Opinion in Plant Biology 2001, 4:86–91. Polysymmetric (more than one plane of symmetry) to monosymmetric in angiosperm (flowering plants) evolution; the other way in Antirrhinaceae. Left and right handed helicity. Bees ...

“Bem biológico mesmo”: tensões entre ensino de biologia, currículo e sexualidade

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Neilton dos Reis

2018-01-01

Full Text Available Neste artigo, apresentamos uma argumentação teórica acerca da construção curricular e história das disciplinas escolares de Ciências e de Biologia e suas relações com os saberes do campo de gênero e sexualidade. Partimos da apresentação e problematização de uma das entrevistas que compuseram a pesquisa “Diversidade de Gêneros e Ensino de Biologia: casos de prazeres e corporeidades não-binárias” para, então, pensar como essas disciplinas se constituem, legitimando, ou não, determinados conhecimentos e conteúdos curriculares. Com isso, propomos uma ação questionadora dos posicionamentos que os currículos vêm promulgando, de forma a repensar os contornos nos quais a sexualidade tem sido delimitada na área das Ciências Biológicas. Palavras-chave: Currículo. Ensino de Biologia. Sexualidade.   “Really biological”: tensions between biology education, curriculum and sexuality ABSTRACT In this article, it is introduced a theoretical argumentation about curricular construction and scholar disciplines story of Science and Biology, and its relations to the knowledge about gender and sexuality. We started from presentation and questioning of one of the interviews that were included in the survey “Gender Diversity and Biology Education: Case of pleasures and corporealities non-binary” to then, think how these disciplines are legitimizing, or not, certain knowledge and content curriculum. Therefore, we propose an action questioning of the positions that curriculum have been promulgating in order to rethink the contours in which sexuality has been defined in the area of Biological Sciences. Keywords: Curriculum. Biology education. Sexuality.   “Bien biológico mismo”: tensiones entre la enseñanza de la biología, currículo y sexualidad RESUMEN En este artículo, presentamos una argumentación teórica acerca de la construcción curricular y de la historia de las disciplinas escolares de Ciencias y de Biología y

Determinação do ponto de colheita e indução à abertura floral do crisântemo cultivar White Polaris em diferentes concentrações de sacarose Stage of harvest and flower opening induction at different sucrose concentrations in spray chrysánthemum cv. White Polaris

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Victor Julio Flórez Roncancio

1995-01-01

Full Text Available Realizou-se pesquisa objetivando determinar o melhor entre quatro pontos de colheita da haste floral de crisântemos de maço do tipo pompom cv. White Polaris a concentração mais adequada de sacarose para tratamento de "pulsing" dessas hastes: estas foram colhidas em estufa de produção comercial, nos pontos preestabelecidos e transportadas para laboratório, onde foram totalmente imersas em água de torneira, à sombra, durante três horas. Selecionaram-se as hastes pela uniformidade do seu desenvolvimento e cortaram-nas sob água na base do caule, entre 50 e 60 cm, e identificadas, o que permitiu avaliar as mudanças morfológicas associadas às inflorescências individuais. As hastes foram distribuídas e mantidas nos diferentes tratamentos de "pulsing" durante 24 horas, à luz branca contínua de 1.500 lux, 60 a 90% de umidade relativa do ar e temperatura ambiente de 25 ± 2°C. Após o tratamento de "pulsing", as hastes foram transferidas para água destilada, permanecendo por 10 horas sob luz branca contínua, nas mesmas condições de laboratório citadas. A vida floral em vaso começou a ser avaliada na instalação do experimento, após o tratamento de "pulsing", e terminou quando as folhas e pétalas perderam a turgescência e o valor decorativo. As hastes colhidas em estádio de botão (25 e 50% de abertura das inflorescências apicais não alcançaram o ponto de abertura adequado em nenhuma das seis concentrações de sacarose (0 a 146,07 mol/m³; as concentrações de 116,9 146,1 mol/m³, porém, estimularam, em geral, a abertura de botões. Os pontos de colheita 1 e 2 (100 e 75% de abertura das inflorescências apicais respectivamente apresentaram bons resultados em todas as concentrações de sacarose.Flowers of spray chrysanthemum cv. White Polaris were cut at 4 stages and treated in pulsing solutions of distilled water plus 0 to 146.1 mol/m³ sucrose. The flowers were harvested in local commercial greenhouses, at various

Biologia molecular do câncer colorretal: uma revolução silenciosa em andamento Molecular biology of colorectal cancer: a silent revolution

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Mauro de Souza Leite Pinho

2008-09-01

Full Text Available Embora os estudos sobre biologia molecular permaneçam como a principal expectativa para o surgimento de novos conceitos e recursos para o tratamento do câncer colorretal, a ausência de resultados de real impacto do ponto de vista clínico ao longo dos últimos anos podem representar uma frustração para quem não esteja acompanhando de perto a evolução das pesquisas nesta área. Assim sendo, nosso objetivo no presente texto é apresentar uma breve revisão do caminho percorrido até o momento desde os trabalhos pioneiros sobre carcinogênese colorretal até as pesquisas mais recentes sobre proteômica, demonstrando assim o constante fluxo de grandes avanços os quais possibilitam uma previsão realista a curto ou médio prazo da disponibilização de recursos de amplo impacto, com potencial para alterar de forma relevante os resultados do tratamento desta importante doença.Despite remaining as the main hope for emerging new concepts and strategies for treatment of colorectal cancer, the lack of results with clinical impact over the last years may contribute to frustrate those not entirely aware about current research data. So, the aim of this paper is to present a brief review since the first molecular biology studies in colorectal carcinogenesis until recent advances in proteomics, in order to demonstrate the consistent production of new data supporting a realistic expectancy for a near future availability of high impact resources that may change dramatically the results of treatment of colorectal cancer.

Floral function: effects of traits on pollinators, male and female pollination success, and female fitness across three species of milkweeds (Asclepias).

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La Rosa, Raffica J; Conner, Jeffrey K

2017-01-01

Central questions in plant reproductive ecology are whether the functions of floral traits in hermaphrodites create conflict between sexes that could slow evolution, and whether individual floral traits function in pollinator attraction, efficiency, or both. We studied how floral traits affect pollinator visitation and efficiency, and how they affect male and female function and female fitness within and across three Asclepias species that differ in floral morphology. Using separate multiple regressions, we regressed pollen removal, deposition, and fruit number onto six floral traits. We also used path analyses integrating these variables with pollinator visitation data for two of the species to further explore floral function and its effects on fruit production. Most traits affected male pollination success only, and these effects often differed between species. The exception was increased slit length, which increased pollinia insertion in two of the species. There were no interspecific differences in the effects of the traits on female pollination success. All traits except horn reach affected pollination efficiency in at least one species, and horn reach and two hood dimensions were the only traits to affect pollinator attraction, but in just one species. Traits tended to function in only one sex, and more traits affected function through pollinator efficiency than through attraction. There was no significant link between female pollination success and female fitness in any of the three species; this pattern is consistent with fruit production not being limited by pollen deposition. © 2017 Botanical Society of America.

Time-Dependent Trapping of Pollinators Driven by the Alignment of Floral Phenology with Insect Circadian Rhythms

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Jenny Y. Y. Lau

2017-06-01

Full Text Available Several evolutionary lineages in the early divergent angiosperm family Annonaceae possess flowers with a distinctive pollinator trapping mechanism, in which floral phenological events are very precisely timed in relation with pollinator activity patterns. This contrasts with previously described angiosperm pollinator traps, which predominantly function as pitfall traps. We assess the circadian rhythms of pollinators independently of their interactions with flowers, and correlate these data with detailed assessments of floral phenology. We reveal a close temporal alignment between patterns of pollinator activity and the floral phenology driving the trapping mechanism (termed ‘circadian trapping’ here. Non-trapping species with anthesis of standard duration (c. 48 h cannot be pollinated effectively by pollinators with a morning-unimodal activity pattern; non-trapping species with abbreviated anthesis (23–27 h face limitations in utilizing pollinators with a bimodal circadian activity; whereas species that trap pollinators (all with short anthesis can utilize a broader range of potential pollinators, including those with both unimodal and bimodal circadian rhythms. In addition to broadening the range of potential pollinators based on their activity patterns, circadian trapping endows other selective advantages, including the possibility of an extended staminate phase to promote pollen deposition, and enhanced interfloral movement of pollinators. The relevance of the alignment of floral phenological changes with peaks in pollinator activity is furthermore evaluated for pitfall trap pollination systems.

Zooming-in on floral nectar: a first exploration of nectar-associated bacteria in wild plant communities.

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Alvarez-Pérez, Sergio; Herrera, Carlos M; de Vega, Clara

2012-06-01

Floral nectar of some animal-pollinated plants usually harbours highly adapted yeast communities which can profoundly alter nectar characteristics and, therefore, potentially have significant impacts on plant reproduction through their effects on insect foraging behaviour. Bacteria have also been occasionally observed in floral nectar, but their prevalence, phylogenetic diversity and ecological role within plant-pollinator-yeast systems remains unclear. Here we present the first reported survey of bacteria in floral nectar from a natural plant community. Culturable bacteria occurring in a total of 71 nectar samples collected from 27 South African plant species were isolated and identified by 16S rRNA gene sequencing. Rarefaction-based analyses were used to assess operational taxonomic units (OTUs) richness at the plant community level using nectar drops as sampling units. Our results showed that bacteria are common inhabitants of floral nectar of South African plants (53.5% of samples yielded growth), and their communities are characterized by low species richness (18 OTUs at a 16S rRNA gene sequence dissimilarity cut-off of 3%) and moderate phylogenetic diversity, with most isolates belonging to the Gammaproteobacteria. Furthermore, isolates showed osmotolerance, catalase activity and the ability to grow under microaerobiosis, three traits that might help bacteria to overcome important factors limiting their survival and/or growth in nectar. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Terapia floral em gatos domésticos (Felis catus, Linnaeus, 1758 portadores do complexo da doença respiratória felina: estudo clínico e hematológico Flower therapy in domestic cats (Felis catus, Linnaeus, 1758 with feline respiratory disease complex: clinical and hematological study

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R.F. Araújo

2010-12-01

Full Text Available A terapia floral é considerada, atualmente, prática médica alternativa utilizada em diversas situações clínicas, constituindo possibilidade a mais de prevenção e cura de muitas doenças de natureza física e emocional. Este estudo objetivou pesquisar o efeito das essências do Sistema Brasileiro de Florais Compostos de Joel Aleixo num mesmo grupo de gatos domésticos com sinais clínicos sugestivos de Doença Respiratória Felina (DRF, tratados em diferentes momentos (M0, M1, M2, M3. Foram utilizados 20 gatos domésticos, de ambos os sexos, sem raça definida, com idade média de 5,63 ± 3,02 anos criados em gatil na UFRPE. Os animais foram submetidos ao tratamento com os florais por via oral em duas etapas. Na primeira etapa com os florais Desintus Total e Helminthus Total por 14 dias, e na segunda etapa com os florais Antibius e Regius por 28 dias. Os resultados observados, quanto aos aspectos clínicos, foram redução de secreção nasal, secreção ocular e estertores pulmonares; desaparecimento de sinais clínicos como fezes alteradas, úlceras na cavidade oral, pêlos eriçados e permanência da hipertrofia dos linfonodos. Quanto aos aspectos hematológicos houve interferência nas variáveis relacionadas ao hemograma (hemoglobina, VCM, CHCM, leucócitos, linfócitos e monócitos. Conclui-se que a terapia floral mostrou-se eficaz em gatos domésticos com sinais sugestivos de DRF criados nas mesmas condições de manejo.Flower therapy is currently considered an alternative medical practice used in several clinical situations, providing another way to prevent and cure many diseases of physical and emotional nature. This study aimed to investigate the effect of essences of the Brazilian Compound Flower System of Joel Aleixo in one same group of domestic cats showing suggestive clinical signs of Feline Respiratory Disease (FRD, treated in different moments (M0, M1, M2, M3. Twenty domestic cats, males and females, of mixed breed, with

A FREQUÊNCIA DE QUESTÕES RELACIONADAS BIOTECNOLOGIA E TECNOLOGIAS DO DNA NO EXAME NACIONAL DO ENSINO MÉDIO (ENEM) E SUA IMPORTÂNCIA NO ENSINO BÁSICO

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Xavier, Cesar Silva

2017-01-01

O presente artigo analisa a frequência em que temas da Biotecnologia tem sido abordados no Exame Nacional do Ensino Médio (ENEM) e a importância da abordagem destes temas junto aos alunos do ensino básico. Foram analisadas as provas de Biologia do caderno amarelo das edições de 2009 a 2015 do ENEM e contabilizados os assuntos relacionados à temas específicos da Biotecnologia e tecnologias do DNA. Por meio desta pesquisa evidenciou-se que dentre os diversos temas da Biologia, o ENEM dedicou o ...

Unique morphological changes in plant pathogenic phytoplasma-infected petunia flowers are related to transcriptional regulation of floral homeotic genes in an organ-specific manner.

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Himeno, Misako; Neriya, Yutaro; Minato, Nami; Miura, Chihiro; Sugawara, Kyoko; Ishii, Yoshiko; Yamaji, Yasuyuki; Kakizawa, Shigeyuki; Oshima, Kenro; Namba, Shigetou

2011-09-01

Abnormal flowers are often induced by infection of certain plant pathogens, e.g. phytoplasma, but the molecular mechanisms underlying these malformations have remained poorly understood. Here, we show that infection with OY-W phytoplasma (Candidatus Phytoplasma asteris, onion yellows phytoplasma strain, line OY-W) affects the expression of the floral homeotic genes of petunia plants in an organ-specific manner. Upon infection with OY-W phytoplasma, floral morphological changes, including conversion to leaf-like structures, were observed in sepals, petals and pistils, but not in stamens. As the expression levels of homeotic genes differ greatly between floral organs, we examined the expression levels of homeotic genes in each floral organ infected by OY-W phytoplasma, compared with healthy plants. The expression levels of several homeotic genes required for organ development, such as PFG, PhGLO1 and FBP7, were significantly downregulated by the phytoplasma infection in floral organs, except the stamens, suggesting that the unique morphological changes caused by the phytoplasma infection might result from the significant decrease in expression of some crucial homeotic genes. Moreover, the expression levels of TER, ALF and DOT genes, which are known to participate in floral meristem identity, were significantly downregulated in the phytoplasma-infected petunia meristems, implying that phytoplasma would affect an upstream signaling pathway of floral meristem identity. Our results suggest that phytoplasma infection may have complex effects on floral development, resulting in the unique phenotypes that were clearly distinct from the mutant flower phenotypes produced by the knock-out or the overexpression of certain homeotic genes. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

First report of predation on floral visitors by crab spiders on Croton selowii Baill. (Euphorbiaceae Primeiro registro de predação de visitantes florais por aranhas-caranguejo em Croton selowii Baill. (Euphorbiaceae

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Reinaldo Rodrigo Novo

2010-06-01

Full Text Available In the literature it has been extensively mentioned that crab spiders (Araneae: Thomisidae prey on floral visitors of several plant species. Here we present observations of Croton selowii Baill. (Euphorbiaceae, a monoecious species harboring individuals of crab spiders in an area of coastal vegetation of Pernambuco state, Brazil. The species is visited by several invertebrate orders, and some of them were preyed upon by the spiders, mainly Diptera species. The spiders rubbed the forelimbs within the flowers, which may constitute a strategy to camouflage these structures. Croton selowii seems to represent a suitable foraging site for the spiders, because it has a generalist pollination system (thus being visited by a wide range of invertebrate species and blooms in a period of low flower resource availability in the area.Na literatura tem sido amplamente registrado que aranhas Thomisidae predam visitantes florais de várias espécies de planta. Neste estudo nós apresentamos observações de Croton selowii Baill. (Euphorbiaceae, uma espécie monóica, abrigando aranhas Thomisidae em uma área de restinga de Pernambuco, Brasil. A espécie é visitada por invertebrados de várias ordens e vários deles são predados pelas aranhas, principalmente espécies de Diptera. As aranhas apresentaram um comportamento de esfregar as pernas dianteiras dentro das flores, o que pode ser interpretado como uma estratégia de camuflagem das pernas. Croton selowii parece representar um bom sítio de forrageamento para essas aranhas, pois possui um sistema de polinização generalista, sendo visitado por ampla gama de invertebrados e floresce em um período de baixa disponibilidade de flores na área.

Dos gêneros textuais utilizados na formação do professor de Biologia

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Odisséa Boaventura de Oliveira

2013-01-01

Full Text Available Problematiza-se nesta pesquisa os gêneros relatório e artigo científico escritos por 4 estudantes- estagiários na disciplina Prática de Ensino de Biologia, tomando-se as funções enunciativas locutor, enunciador e autor, conforme explicitadas por Orlandi (2003. Considera-se o locutor aquele que se representa como 'eu' no discurso; o enunciador é o que representa as 'perspectivas que o eu assume' no discurso e autor, quando se assume enquanto 'produtor' da linguagem, portanto afetado pelo contato com o social e suas coerções. A análise dos textos escritos aponta que tais gêneros não contribuíram expressivamente para manifestações subjetivas do ser e estar professor, por conta disso propõe-se a escrita de textos que levem o autor a se identificar com aquilo que escreve deixando ali suas marcas subjetivas.

FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice.

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Takuya Suzaki

2009-10-01

Full Text Available CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM in Arabidopsis thaliana. In rice (Oryza sativa, FLORAL ORGAN NUMBER2 (FON2, closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM. Here we show that the FON2 SPARE1 (FOS1 gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems.

Effect of Citrus floral extracts on the foraging behavior of the stingless bee Scaptotrigona pectoralis (Dalla Torre)

OpenAIRE

Grajales-Conesa,Julieta; Meléndez Ramírez,Virginia; Cruz-López,Leopoldo; Sánchez Guillén,Daniel

2012-01-01

Effect of Citrus floral extracts on the foraging behavior of the stingless bee Scaptotrigona pectoralis (Dalla Torre). Stingless bees have an important role as pollinators of many wild and cultivated plant species in tropical regions. Little is known, however, about the interaction between floral fragrances and the foraging behavior of meliponine species. Thus we investigated the chemical composition of the extracts of citric (lemon and orange) flowers and their effects on the foraging behavi...

Adubação foliar com micronutrientes em arroz irrigado, em área sistematizada

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Marchezan Enio

2001-01-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito da aplicação de micronutrientes em arroz irrigado, em área de várzea após a sistematização. Foi realizado durante três anos agrícolas em PLANOSSOLO Hidromórfico eutrófico arênico, instalado em local de onde foi retirada uma camada de solo de cerca de 30cm de profundidade. A adubação com N, P e K foi realizada de acordo com a recomendação técnica para a cultura. O delineamento experimental foi de blocos ao acaso com quatro repetições, constituído de um tratamento denominado "completo", contendo os micronutrientes boro (H3BO3, cobre (CuSO4, ferro (FeSO4, manganês (MnCl2, molibdênio (Na2MoO4 e zinco (ZnSO4 e de seis outros formados pela omissão de um micronutriente de cada vez, além de testemunha sem micronutrientes. Em 1996/97, foram aplicados 70g ha-1 Zn, 70g ha-1 Mn, 40g ha-1 Fe, 50g ha-1 B, 12,5g ha-1 Cu e 4g ha-1 Mo, via foliar, no perfilhamento e no início da formação do primórdio floral das plantas de arroz. Em 1997/98, foram utilizadas as mesmas soluções, porém com aplicação apenas no perfilhamento. Em 1998/99, as doses dos micronutrientes foram alteradas para 35g ha-1 Zn, 35g ha-1 Mn, 100g ha-1 B, 20g ha-1 Cu e 12g ha-1 Mo, aplicados no perfilhamento, não sendo utilizado o ferro no tratamento completo nem na composição dos demais tratamentos. A sistematização da área causou redução no teor de matéria orgânica, macro e micronutrientes, exceto o boro e aumento de alumínio no solo. Verificou-se que não houve efeito da aplicação foliar de micronutrientes no rendimento de grãos de arroz irrigado.

What shapes amino acid and sugar composition in Mediterranean floral nectars?

NARCIS (Netherlands)

Petanidou, T.; Van Laere, A.; Ellis, W.; Smets, E.

2006-01-01

We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring in a phryganic (East Mediterranean garrigue) community and investigated whether AA and sugar composition is shaped by evolutionary (plant phylogeny), ecological (flowering time as a direct effect of summer

Effects of range-wide variation in climate and isolation on floral traits and reproductive output of Clarkia pulchella.

Science.gov (United States)

Bontrager, Megan; Angert, Amy L

2016-01-01

Plant mating systems and geographic range limits are conceptually linked by shared underlying drivers, including landscape-level heterogeneity in climate and in species' abundance. Studies of how geography and climate interact to affect plant traits that influence mating system and population dynamics can lend insight to ecological and evolutionary processes shaping ranges. Here, we examined how spatiotemporal variation in climate affects reproductive output of a mixed-mating annual, Clarkia pulchella. We also tested the effects of population isolation and climate on mating-system-related floral traits across the range. We measured reproductive output and floral traits on herbarium specimens collected across the range of C. pulchella. We extracted climate data associated with specimens and derived a population isolation metric from a species distribution model. We then examined how predictors of reproductive output and floral traits vary among populations of increasing distance from the range center. Finally, we tested whether reproductive output and floral traits vary with increasing distance from the center of the range. Reproductive output decreased as summer precipitation decreased, and low precipitation may contribute to limiting the southern and western range edges of C. pulchella. High spring and summer temperatures are correlated with low herkogamy, but these climatic factors show contrasting spatial patterns in different quadrants of the range. Limiting factors differ among different parts of the range. Due to the partial decoupling of geography and environment, examining relationships between climate, reproductive output, and mating-system-related floral traits reveals spatial patterns that might be missed when focusing solely on geographic position. © 2016 Botanical Society of America.

Natural selection on floral morphology can be influenced by climate.

Science.gov (United States)

Campbell, Diane R; Powers, John M

2015-06-07

Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

MOVIMENTOS ENTRE A CULTURA ESCOLAR E CULTURA CIENTÍFICA: ANÁLISE DE ARGUMENTOS EM DIFERENTES CONTEXTOS

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Daniela Lopes-Scarpa

2013-12-01

Full Text Available Para investigar as relações entre a cultura científica e a cultura escolar, analisamos textos científicos e de alunos da educaçãobásica. Usou-se o padrão do argumento de Toulmin e marcaslinguísticas para identificar elementos dos argumentos. Verificamos que os alunos utilizam argumentos substanciais, enquanto que os argumentos dos cientistas são analíticos. A utilização diferenciada dos tempos verbais do discurso permitiu sugerir a transformação da biologia funcional em narrativa histórica. A seleção lexical e de qualificadores tornou visível o deslizamento entre valores de verdade e de conhecimento. Essa análise nos permitiu tecer considerações sobre o caráter híbrido do ensino de ciências.

Isolation and Properties of Floral Defensins from Ornamental Tobacco and Petunia1

Science.gov (United States)

Lay, Fung T.; Brugliera, Filippa; Anderson, Marilyn A.

2003-01-01

The flowers of the solanaceous plants ornamental tobacco (Nicotiana alata) and petunia (Petunia hybrida) produce high levels of defensins during the early stages of development. In contrast to the well-described seed defensins, these floral defensins are produced as precursors with C-terminal prodomains of 27 to 33 amino acids in addition to a typical secretion signal peptide and central defensin domain of 47 or 49 amino acids. Defensins isolated from N. alata and petunia flowers lack the C-terminal domain, suggesting that it is removed during or after transit through the secretory pathway. Immunogold electron microscopy has been used to demonstrate that the N. alata defensin is deposited in the vacuole. In addition to the eight canonical cysteine residues that define the plant defensin family, the two petunia defensins have an extra pair of cysteines that form a fifth disulfide bond and hence define a new subclass of this family of proteins. Expression of the N. alata defensin NaD1 is predominantly flower specific and is most active during the early stages of flower development. NaD1 transcripts accumulate in the outermost cell layers of petals, sepals, anthers, and styles, consistent with a role in protection of the reproductive organs against potential pathogens. The floral defensins inhibit the growth of Botrytis cinerea and Fusarium oxysporum in vitro, providing further support for a role in protection of floral tissues against pathogen invasion. PMID:12644678

Attraction of Plecia nearctica (dipter:bibionidae) to floral lures containing phenylacetaldehyde

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We observed that the floral odorant, phenylacetaldehyde (PAA), was attractive to both sexes of adult lovebugs (Plecia nearctica, Diptera: Bibionidae) in central and southern Florida. The addition of ß-myrcene and methyl salicylate to PAA did not improve the numbers of P. nearctica caught in delta tr...

Pyridine-type alkaloid composition affects bacterial community composition of floral nectar.

Science.gov (United States)

Aizenberg-Gershtein, Yana; Izhaki, Ido; Santhanam, Rakesh; Kumar, Pavan; Baldwin, Ian T; Halpern, Malka

2015-06-30

Pyridine-type alkaloids are most common in Nicotiana species. To study the effect of alkaloid composition on bacterial community composition in floral nectar, we compared the nicotine-rich wild type (WT) N. attenuata, the nicotine biosynthesis-silenced N. attenuata that was rich in anatabine and the anabasine-rich WT N. glauca plants. We found that the composition of these secondary metabolites in the floral nectar drastically affected the bacterial community richness, diversity and composition. Significant differences were found between the bacterial community compositions in the nectar of the three plants with a much greater species richness and diversity in the nectar from the transgenic plant. The highest community composition similarity index was detected between the two wild type plants. The different microbiome composition and diversity, caused by the different pyridine-type alkaloid composition, could modify the nutritional content of the nectar and consequently, may contribute to the change in the nectar consumption and visitation. These may indirectly have an effect on plant fitness.

Teor e composição do óleo essencial de inflorescências e folhas de Lavandula dentata L. em diferentes estádios de desenvolvimento floral e épocas de colheita Yield and composition of essential oil from inflorescences and leaves of lavender (Lavandula dentata L. in different flower development stages and harvest times

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M.A.M. Masetto

2011-01-01

Full Text Available O óleo essencial de Lavandula dentata L. possui importância econômica devido à utilização nas indústrias farmacêutica, cosmética e de higiene pessoal. O presente trabalho teve como objetivo avaliar o teor e a composição do óleo essencial de inflorescências e folhas de lavanda em diferentes estádios de desenvolvimento. O delineamento experimental foi inteiramente casualizado em esquema fatorial 2 x 3, sendo três estádios de desenvolvimento floral (botão, pré-antese/antese e senescente e duas épocas de colheita (janeiro e abril, com cinco repetições. As amostras de óleo essencial foram obtidas por hidrodestilação, sendo os constituintes analisados por cromatografia em fase gasosa acoplada à espectrometria de massas (CG/EM. Houve interação entre os fatores épocas de colheita e desenvolvimento floral no teor de óleo essencial das inflorescências, sendo observada média superior em botões florais colhidos em janeiro. Os estádios de desenvolvimento não alteraram o teor do óleo essencial das folhas. Os estádios de desenvolvimento influenciaram nos teores dos constituintes dos óleos essenciais das inflorescências e folhas. No óleo essencial em estádio de flor senescente da colheita de abril, observou-se teor elevado de 1,8-cineol, enquanto nos demais estádios de desenvolvimento os teores foram menores em ambas as épocas de colheita. Teores elevados de cânfora foram observados nos estádios de pré-antese/antese e senescente, na colheita de janeiro. O óleo essencial das folhas apresentou teor superior de 1,8-cineol em ramos com flores em estádio de pré-antese/antese. Os teores de cânfora e fenchona foram superiores em ramos contendo botões. O óleo essencial das folhas de ramos com botões e flores senescentes apresentou teor superior de linalol em relação ao óleo essencial das inflorescências.The essential oil of Lavandula dentata L. has economic importance due to its utilization by pharmaceutical

Differential expressions of putative genes in various floral organs of ...

African Journals Online (AJOL)

STORAGESEVER

2009-06-03

Jun 3, 2009 ... Full Length Research Paper. Differential expressions of putative genes in various floral organs of the Pigeon orchid (Dendrobium crumenatum) using GeneFishing. Faridah, Q. Z.1, 2, Ng, B. Z.3, Raha, A. R.4, Umi, K. A. B.5 and Khosravi, A. R.2*. 1Department of Biology, Faculty Science, University Putra ...

Flowering mechanisms, pollination strategies and floral scent analyses of syntopically co-flowering Homalomena spp. (Araceae) on Borneo.

Science.gov (United States)

Hoe, Y C; Gibernau, M; Maia, A C D; Wong, S Y

2016-07-01

In this study, the flowering mechanisms and pollination strategies of seven species of the highly diverse genus Homalomena (Araceae) were investigated in native populations of West Sarawak, Borneo. The floral scent compositions were also recorded for six of these species. The selected taxa belong to three out of four complexes of the section Cyrtocladon (Hanneae, Giamensis and Borneensis). The species belonging to the Hanneae complex exhibited longer anthesis (53-62 h) than those of the Giamensis and Borneensis complexes (ca. 30 h). Species belonging to the Hanneae complex underwent two floral scent emission events in consecutive days, during the pistillate and staminate phases of anthesis. In species belonging to the Giamensis and Borneensis complexes, floral scent emission was only evident to the human nose during the pistillate phase. A total of 33 volatile organic compounds (VOCs) were detected in floral scent analyses of species belonging to the Hanneae complex, whereas 26 VOCs were found in samples of those belonging to the Giamensis complex. The floral scent blends contained uncommon compounds in high concentration, which could ensure pollinator discrimination. Our observations indicate that scarab beetles (Parastasia gestroi and P. nigripennis; Scarabaeidae, Rutelinae) are the pollinators of the investigated species of Homalomena, with Chaloenus schawalleri (Chrysomelidae, Galeuricinae) acting as a secondary pollinator. The pollinators utilise the inflorescence for food, mating opportunities and safe mating arena as rewards. Flower-breeding flies (Colocasiomyia nigricauda and C. aff. heterodonta; Diptera, Drosophilidae) and terrestrial hydrophilid beetles (Cycreon sp.; Coleoptera, Hydrophilidae) were also frequently recovered from inflorescences belonging to all studied species (except H. velutipedunculata), but they probably do not act as efficient pollinators. Future studies should investigate the post-mating isolating barriers among syntopically co

Nectar sugars and bird visitation define a floral niche for basidiomycetous yeast on the Canary Islands.

Science.gov (United States)

Mittelbach, Moritz; Yurkov, Andrey M; Nocentini, Daniele; Nepi, Massimo; Weigend, Maximilian; Begerow, Dominik

2015-02-01

Studies on the diversity of yeasts in floral nectar were first carried out in the late 19th century. A narrow group of fermenting, osmophilous ascomycetes were regarded as exclusive specialists able to populate this unique and species poor environment. More recently, it became apparent that microorganisms might play an important role in the process of plant pollination. Despite the importance of these nectar dwelling yeasts, knowledge of the factors that drive their diversity and species composition is scarce. In this study, we linked the frequencies of yeast species in floral nectars from various host plants on the Canary Islands to nectar traits and flower visitors. We estimated the structuring impact of pollination syndromes (nectar volume, sugar concentration and sugar composition) on yeast diversity.The observed total yeast diversity was consistent with former studies, however, the present survey yielded additional basidiomycetous yeasts in unexpectedly high numbers. Our results show these basidiomycetes are significantly associated with ornithophilous flowers. Specialized ascomycetes inhabit sucrose-dominant nectars, but are surprisingly rare in nectar dominated by monosaccharides. There are two conclusions from this study: (i) a shift of floral visitors towards ornithophily alters the likelihood of yeast inoculation in flowers, and (ii) low concentrated hexose-dominant nectar promotes colonization of flowers by basidiomycetes. In the studied floral system, basidiomycete yeasts are acknowledged as regular members of nectar. This challenges the current understanding that nectar is an ecological niche solely occupied by ascomycetous yeasts.

Assessing risks and benefits of floral supplements in conservation biological control

NARCIS (Netherlands)

Winkler, K.; Wackers, F.L.; Termorshuizen, A.J.; Lenteren, van J.C.

2010-01-01

The use of flowering field margins is often proposed as a method to support biological control in agro-ecosystems. In addition to beneficial insects, many herbivores depend on floral food as well. The indiscriminate use of flowering species in field margins can therefore lead to higher pest numbers.

Study of the chemical composition of essential oils and floral waters ...

African Journals Online (AJOL)

This work aimed to study the chemical composition of essential oils and floral waters of Cymbopogon citratus (DC.) Stapf (Poaceae) from Senegal. The plants were collected in two different localities, Dakar and. Kaolack. The extracts were obtained by steam distillation from both fresh and dried plants and analyses carried.

Preferência Floral de Vespas (Hymenoptera, Vespidae no Rio Grande do Sul, Brasil

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Alexandre Somavilla

2012-03-01

Abstract Wasps integrate the floral visitors’ community and they can constitute a representative portion of the pollinators. For this reason, it was aimed to know and to analyze the floral preference of the Vespidae species and to investigate the use of floral resources for these wasps. The collects were performed between 2001 and 2008 in different localities of Rio Grande do Sul state (Estrela Velha, Santa Cruz do Sul, São Francisco de Paula e Sinimbu between 08:00 at 17:00 hours, utilizing entomological nets to catch the flower-visiting wasps. The collected specimens were deposited at the Coleção Entomológica de Santa Cruz do Sul (CESC. 1.483 specimens were captured belonging to 73 wasp species, whose 78.9% were Polistinae (30 species and 21.1% Eumeninae (43 species, visiting the flowers of 33 plant species classified in 16 botanical families; the families with the larger number of plant species were Asteraceae (12, Fabaceae (4 and Apiaceae (3. The plant species with the largest number of wasps collected was Schinus terebinthifolius Raddi (616, followed by Eryngium pandanifolium L. (137 and Eryngium horridum Spreng (122. The analysis of the trophic niche overlap of 26 species with four or more visited plant species, showed an overlap equal or higher than 50% in six cases.

Enhancing resource availability in agro-ecosystems for beneficial arthropods through floral provisioning

Science.gov (United States)

There has been a decline in beneficial arthropods (insects and spiders) including pollinators because of habitat destruction and intense management practices. Enhancing landscapes with additional floral and other non-crop habitats has the potential to attract pollinators, and predatory arthropods wh...

Atração e desenvolvimento de Leptoglossus gonagra (Fabr. (Hemiptera: Coreidae em cultivares de abóbora e moranga

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Baldin Edson Luiz Lopes

2002-01-01

Full Text Available As plantas da família Cucurbitaceae são seriamente prejudicadas pelo ataque de insetos, sendo que os danos ocorrem desde a germinação até a colheita e podem ser observados em todas as partes da planta. Dentre os insetos sugadores que atacam a abóbora (Cucurbita moschata e a moranga (C. maxima, as formas jovens e adultas do percevejo Leptoglossus gonagra (Fabr. (Hemiptera: Coreidae merecem destaque por sugarem a seiva das folhas, ramos e frutos novos, nos quais causam necroses, reduzindo a produção. Visando comparar a atratividade de plântulas de cultivares de abóbora e moranga a adultos deste percevejo e os efeitos desses materiais sobre a biologia de ninfas dessa espécie, realizaram-se ensaios sob condições de laboratório. Em teste de atratividade, o cultivar de abóbora BRA015113 destacou-se como o menos atrativo em relação ao cultivar de moranga Exposição, enquanto que o cultivar de abóbora BRA003531 foi o mais atrativo. Todos os cultivares provocaram 100% de mortalidade das ninfas, indicando a presença de componentes antibióticos, adversos ao desenvolvimento de L. gonagra.

Geometric morphometrics of functionally distinct floral organs in Iris pumila: Analyzing patterns of symmetric and asymmetric shape variations

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Radović Sanja

2017-01-01

Full Text Available The Iris flower is a complex morphological structure composed of two trimerous whorls of functionally distinct petaloid organs (the falls and the standards, one whorl of the stamens and one tricarpellary gynoecium. The petal-like style arms of the carpels are banded over the basal part of the falls, forming three pollination tunnels, each of which is perceived by the Iris pollinators as a single bilaterally symmetrical flower. Apart from the stamens, all petaloid floral organs are preferentially involved in advertising rewards to potential pollinators. Here we used the methods of geometric morphometrics to explore the shape variation in falls, standards and style arms of the Iris pumila flowers and to disentangle the symmetric and the asymmetric component of the total shape variance. Our results show that symmetric variation contributes mostly to the total shape variance in each of the three floral organs. Fluctuating asymmetry (FA was the dominant component of the asymmetric shape variation in the falls and the standards, but appeared to be marginally significant in the style arms. The values of FA indexes for the shape of falls (insects’ landing platforms and for the shape of standards (long-distance reward signals were found to be two orders of magnitude greater compared to that of the style arms. Directional asymmetry appeared to be very low, but highly statistically significant for all analyzed floral organs. Because floral symmetry can reliably indicate the presence of floral rewards, an almost perfect symmetry recorded for the style arm shape might be the outcome of pollinator preferences for symmetrical pollination units. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173007

Biologia de nidificação de Centris (Hemisiella trigonoides Lepeletier (Hymenoptera, Apidae, Centridini Nesting biology of Centris (Hemisiella trigonoides Lepeletier (Hymenoptera, Apidae, Centridini

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Cândida M. L. Aguiar

2006-06-01

Full Text Available O comportamento de nidificação de Centris (Hemisiella trigonoides Lepeletier, 1841, e o comportamento de seus cleptoparasitas foram estudados em Monte Santo, Bahia, Brasil. As abelhas construíram seus ninhos com uma mistura de solo e óleo, dentro de cavidades preexistentes na madeira de uma construção abandonada, assim como em gomos de bambu de 8 e 9 mm de diâmetro. Os ninhos completados tinham de uma a cinco células alongadas, arranjadas em uma série linear e orientadas horizontalmente. O tempo gasto para construir uma célula foi altamente variável, sendo em geral de 4,5 a 5,5 h. Após finalizar a construção da célula, as fêmeas fizeram uma ou duas viagens para coletar um líquido incolor, provavelmente óleo floral, usado para revestir as paredes internas da célula. Para aprovisionar uma célula foram realizadas de cinco a oito viagens de coleta para obtenção de pólen e néctar, e de quatro a seis viagens para coleta de óleo. Imediatamente após a oviposição, as fêmeas fecharam as células usando o solo que elas tinham coletado previamente. Três espécies cleptoparasitas pertencentes ao gênero Coelioxys Latreille, 1809 atacaram os ninhos. Entradas de cleptoparasitas dentro dos ninhos occorreram, na maioria dos casos, enquanto a fêmea hospedeira estava ausente do ninho. As fêmeas de C. (H. trigonoides apresentaram comportamentos defensivos para evitar parasitismo, tais como expulsar os parasitas e guardar os ninhos. Machos de C. (H. trigonoides usaram o local de nidificação como abrigo durante as horas mais quentes do dia, assim como para dormir. Eles deixavam as cavidades no dia seguinte entre 09:00 e 10:30 h. Isto sugere que machos e fêmeas têm padrões temporais de atividade distintos.The nesting behavior of Centris (Hemisiella trigonoides Lepeletier, 1841, and the behavior of their cleptoparasites were studied at Monte Santo, Bahia, Brazil. The females constructed their nests within preexisting holes in wood

Mapping floral resources for honey bees in New Zealand at the catchment scale.

Science.gov (United States)

Ausseil, Anne-Gaelle E; Dymond, John R; Newstrom, Linda

2018-03-12

Honey bees require nectar and pollen from flowers: nectar for energy and pollen for growth. The demand for nectar and pollen varies during the year, with more pollen needed in spring for colony population growth and more nectar needed in summer to sustain the maximum colony size and collect surplus nectar stores for winter. Sufficient bee forage is therefore necessary to ensure a healthy bee colony. Land-use changes can reduce the availability of floral resources suitable for bees, thereby increasing the susceptibility of bees to other stressors such as disease and pesticides. In contrast, land-based management decisions to protect or plant bee forage can enhance pollen and nectar supply to bees while meeting other goals such as riparian planting for water-quality improvement. Commercial demand for honey can also put pressure on floral resources through over-crowding of hives. To help understand and manage floral resources for bees, we developed a spatial model for mapping monthly nectar and pollen production from maps of land cover. Based on monthly estimated production data we mapped potential monthly supply of nectar and pollen to a given apiary location in the landscape. This is done by summing the total production within the foraging range of the apiary while subtracting the estimated nectar converted to energy for collection. Ratios of estimated supply over theoretical hive demand may then be used to infer a potential landscape carrying capacity to sustain hives. This model framework is quantitative and spatial, utilizing estimated flight energy costs for nectar foraging. It can contribute to management decisions such as where apiaries could be placed in the landscape depending on floral resources and where nectar limited areas may be located. It can contribute to planning areas for bee protection or planting such as in riparian vegetation. This would aid managed bee health, wild pollinator protection, and honey production. We demonstrate the methods in a

Estimativas de parâmetros populacionais e demográficos de Ozotoceros bezoarticus (Artiodactyla, Cervidae) em Piraí do Sul, Paraná, sul do Brasil Estimates of population and demographic parameters of Ozotoceros bezoarticus (Artiodactyla, Cervidae) in Piraí do Sul, Paraná, southern Brazil

OpenAIRE

Fernanda G. Braga; Yoshiko S. Kuniyoshi

2010-01-01

Este estudo foi realizado em duas propriedades particulares, situadas no município de Piraí do Sul, sul do Brasil. Foram realizadas 16 fases de campo mensais, com três dias de duração, no período compreendido entre fevereiro de 2001 e maio de 2002, com o objetivo de obter informações sobre a biologia do veado-campeiro (Ozotoceros bezoarticus Linnaeus, 1758) e identificar os principais fatores de impacto sobre o mesmo. Foram computadas 1.065 observações, estimando-se 71,45 indivíduos na popula...

Herbivore-Induced DNA Demethylation Changes Floral Signalling and Attractiveness to Pollinators in Brassica rapa.

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Roman T Kellenberger

Full Text Available Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities.

Study of the chemical composition of essential oils and floral waters ...

African Journals Online (AJOL)

This work aimed to study the chemical composition of essential oils and floral waters of Cymbopogon citratus (DC.) Stapf (Poaceae) from Senegal. The plants were collected in two different localities, Dakar and Kaolack. The extracts were obtained by steam distillation from both fresh and dried plants and analyses carried ...

The dilemma of being a fragrant flower: the major floral volatile attracts pollinators and florivores in the euglossine-pollinated orchid Dichaea pendula.

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Nunes, Carlos E P; Peñaflor, Maria Fernanda G V; Bento, José Maurício S; Salvador, Marcos José; Sazima, Marlies

2016-12-01

Volatile organic compounds (VOCs) mediate both mutualistic and antagonistic plant-animal interactions; thus, the attraction of mutualists and antagonists by floral VOCs constitutes an important trade-off in the evolutionary ecology of angiosperms. Here, we evaluate the role of VOCs in mediating communication between the plant and its mutualist and antagonist floral visitors. To assess the evolutionary consequences of VOC-mediated signalling to distinct floral visitors, we studied the reproductive ecology of Dichaea pendula, assessing the effects of florivores on fruit set, the pollination efficiency of pollinators and florivores, the floral scent composition and the attractiveness of the major VOC to pollinators and florivores. The orchid depends entirely on orchid-bees for sexual reproduction, and the major florivores, the weevils, feed on corollas causing self-pollination, triggering abortion of 26.4 % of the flowers. Floral scent was composed of approximately 99 % 2-methoxy-4-vinylphenol, an unusual floral VOC attractive to pollinators and florivores. The low fruit set from natural pollination (5.6 %) compared to hand cross-pollination (45.5 %) and low level of pollinator visitation [0.02 visits (flower hour) -1 ] represent the limitations to pollination. Our research found that 2-methoxy-4-vinylphenol mediates both mutualistic and antagonistic interactions, which could result in contrary evolutionary pressures on novo-emission. The scarcity of pollinators, not florivory, was the major constraint to fruit set. Our results suggest that, rather than anti-florivory adaptations, adaptations to enhance pollinator attraction and cross-pollination might be the primary drivers of the evolution of VOC emission in euglossine-pollinated flowers.

Floral Sources for Stingless Bees (Tetragonula iridipennis in Nellithurai Village, Tamilnadu, India

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K. Vijayakumar

2016-10-01

Full Text Available We documented 45 plant taxa belonging to 29 families and non-floral sources utilized by Tetragonula iridipennis for pollen, nectar and resin. The foragers of T. iridipennis were also found to collect non-floral resources like fruit juice, fruits kept in the market for sales and from falling and damaged mango and jasmine fruits. The mutualistic association between T. iridipennis colonies and Hemipterans was observed and documented. According to pollen analysis, all are appeared to be multifloral honeys. The families Arecaceae and Fabaceae had a significant importance amongst the samples represented by four pollen types. Coconut, Sunflower and Banana pollen types occurred most constantly among the samples. The present palynological analysis of honey samples can provide the accurate depiction of the bee flora in Nellithurai village. The present study to help the beekeepers to know the stingless bee flora and to identify the botanical origins of honey.

Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

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Tóth, Peter; Undas, Anna K.; Verstappen, Francel; Bouwmeester, Harro

2016-01-01

The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

Calendário floral de plantas melíferas nativas da Borda Oeste do Pantanal no Estado do Mato Grosso do Sul

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Suzana Maria Salis

2015-10-01

Full Text Available Resumo:O objetivo deste trabalho foi avaliar o padrão de floração, ao longo do ano, de plantas melíferas na Borda Oeste do Pantanal, no Maciço do Urucum, MS, bem como o tipo de recurso oferecido pela flora melífera, para elaborar um calendário floral para a região. A floração das plantas melíferas visitadas pelas abelhas nativas e africanizadas foi acompanhada quinzenalmente, por 3 anos consecutivos, tendo-se anotado a data de florescimento, o hábito de crescimento e os recursos coletados pelos insetos. Foram identificadas 160 espécies florescendo e sendo visitadas pelas abelhas, mas somente 73 espécies foram consideradas como plantas melíferas e incluídas no calendário floral, das quais 34 eram ervas, 17 árvores, 15 arbustos e 7 lianas. Foram observadas plantas melíferas em flor ao longo de todo o ano, com maior número no verão e menor no inverno. As ervas florescem mais intensamente no verão e no outono (janeiro-junho, enquanto as árvores e os arbustos, na primavera (final de setembro-dezembro. As lianas florescem, principalmente, no final do verão (março-abril. Néctar e pólen são oferecidos às abelhas ao longo de todo o ano, com diminuição da oferta nos meses de inverno (julho-setembro.

Efeitos de extratos de plantas na biologia de Spodoptera frugiperda (J. E. Smith, 1797 (Lepidoptera: Noctuidae mantida em dieta artificial Effects of plant extracts on the biology of Spodoptera frugiperda (J. E. Smith, 1797 (Lepidoptera: Noctuidae maintained under artificial diet

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Gilberto Pedreira Santiago

2008-06-01

Full Text Available Avaliaram-se os efeitos dos extratos aquosos a 10% de folhas e ramos de arruda (Ruta graveolens L., folhas e ramos de melão-de-são-caetano (Momordica charantia L., folhas do alecrim-pimenta (Lippia sidoides Cham. e fruto verde de mamona (Ricinus communis L., sobre a biologia da lagarta-do-cartucho do milho (Spodoptera frugiperda, mantida em dieta artificial. Os parâmetros avaliados foram duração e viabilidade das fases larval e pupal, peso de pupa, fecundidade, fertilidade e longevidade de adultos. Larvas de S. frugiperda recém-eclodidas foram colocadas em tubos de ensaio com dieta artificial, contendo os extratos de cada material testado. O extrato aquoso do fruto verde de R. communis apresentou bioatividade, nos parâmetros duração larval e pupal e peso de pupa. O extrato aquoso de R. graveolens reduziu o peso de pupa. A dieta contendo extrato de folhas e ramos de M. charantia reduziu a viabilidade larval e o peso de pupa. O extrato aquoso de folhas de L. sidoides não afetou as fases larval e pupal, reduziu a postura e a viabilidade de ovos e aumentou a longevidade de adultos de S. frugiperda. A viabilidade de pupa não foi afetada pelos extratos testados.The effects of aqueous extracts, at 10% concentration of leaves and branches of Ruta graveolens L., leaves and branches of Momordica charantia L., leaves of Lippia sidoides Cham. and green fruits of Ricinus communis L. were evaluated on the biology of fall armyworm (Spodoptera frugiperda maintained under artificial diet. The evaluated parameters were: duration and viability of the larval and pupal phases, pupa weight, fecundity, fertility and longevity of adults. Just-hatched larvae of S. frugiperda was placed in test tube with artificial diet containing extracts of each tested material. The aqueous extract of the green fruits of R. communis presented bioactivity upon duration and weight of larval and pupal phases. The aqueous extract of R. graveolens reduced weight of pupa. The diet

As práticas educativas e seus personagens na visão de estudantes recém-ingressados nos cursos de Química e Biologia Educational practices and their characters in freshman Chemistry and Biology major' students view

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Ana Luiza de Quadros

2010-01-01

Full Text Available Desenvolvemos o presente trabalho com o objetivo de identificar concepções sobre as relações em sala de aula apresentadas por alunos recém-ingressados nos cursos de Química e Biologia. Baseados em Bruner, usamos a narrativa como instrumento investigativo dessas concepções, solicitando aos alunos que se imaginassem professores e relatassem como seria um dia de suas vidas. Pela análise dos relatos, percebemos que o professor é aquele que estuda e se prepara para as aulas, transmite conhecimentos, motiva, contextualiza, tem uma boa relação com os alunos e é admirado por eles. Além disso, esse professor é considerado um profissional em tempo integral, trabalhando, sobretudo, no Ensino Médio, com alunos interessados e atenciosos. Entender como essas concepções se formaram e problematizá-las na formação inicial é importante.We developed the present work aiming to identify conceptions about the relationships in classroom presented by freshman Chemistry and Biology major' students. Based on Bruner, we have used narrative as investigative instrument of these conceptions, requesting the students to imagine themselves as teachers and to report how it would be one day of their lives. By the analysis of the stories we have perceived that the teacher is the one who studies and prepares the classes, transmits knowledge, motivates, contextualizes, has a good relationship with students and is admired by them. Moreover, this teacher is a full time professional, working mainly at High School with interested and considerate students. The understanding of how these conceptions were formed and discussing them among pre-service teachers is important.

Floral-dip transformation of flax (Linum usitatissimum) to generate transgenic progenies with a high transformation rate.

Science.gov (United States)

Bastaki, Nasmah K; Cullis, Christopher A

2014-12-19

Agrobacterium-mediated plant transformation via floral-dip is a widely used technique in the field of plant transformation and has been reported to be successful for many plant species. However, flax (Linum usitatissimum) transformation by floral-dip has not been reported. The goal of this protocol is to establish that Agrobacterium and the floral-dip method can be used to generate transgenic flax. We show that this technique is simple, inexpensive, efficient, and more importantly, gives a higher transformation rate than the current available methods of flax transformation. In summary, inflorescences of flax were dipped in a solution of Agrobacterium carrying a binary vector plasmid (T-DNA fragment plus the Linum Insertion Sequence, LIS-1) for 1 - 2 min. The plants were laid flat on their side for 24 hr. Then, plants were maintained under normal growth conditions until the next treatment. The process of dipping was repeated 2 - 3 times, with approximately 10 - 14 day intervals between dipping. The T1 seeds were collected and germinated on soil. After approximately two weeks, treated progenies were tested by direct PCR; 2 - 3 leaves were used per plant plus the appropriate T-DNA primers. Positive transformants were selected and grown to maturity. The transformation rate was unexpectedly high, with 50 - 60% of the seeds from treated plants being positive transformants. This is a higher transformation rate than those reported for Arabidopsis thaliana and other plant species, using floral-dip transformation. It is also the highest, which has been reported so far, for flax transformation using other methods for transformation.

Circadian clock gene LATE ELONGATED HYPOCOTYL directly regulates the timing of floral scent emission in Petunia.

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Fenske, Myles P; Hewett Hazelton, Kristen D; Hempton, Andrew K; Shim, Jae Sung; Yamamoto, Breanne M; Riffell, Jeffrey A; Imaizumi, Takato

2015-08-04

Flowers present a complex display of signals to attract pollinators, including the emission of floral volatiles. Volatile emission is highly regulated, and many species restrict emissions to specific times of the day. This rhythmic emission of scent is regulated by the circadian clock; however, the mechanisms have remained unknown. In Petunia hybrida, volatile emissions are dominated by products of the floral volatile benzenoid/phenylpropanoid (FVBP) metabolic pathway. Here we demonstrate that the circadian clock gene P. hybrida LATE ELONGATED HYPOCOTYL (LHY; PhLHY) regulates the daily expression patterns of the FVBP pathway genes and floral volatile production. PhLHY expression peaks in the morning, antiphasic to the expression of P. hybrida GIGANTEA (PhGI), the master scent regulator ODORANT1 (ODO1), and many other evening-expressed FVBP genes. Overexpression phenotypes of PhLHY in Arabidopsis caused an arrhythmic clock phenotype, which resembles those of LHY overexpressors. In Petunia, constitutive expression of PhLHY depressed the expression levels of PhGI, ODO1, evening-expressed FVBP pathway genes, and FVBP emission in flowers. Additionally, in the Petunia lines in which PhLHY expression was reduced, the timing of peak expression of PhGI, ODO1, and the FVBP pathway genes advanced to the morning. Moreover, PhLHY protein binds to cis-regulatory elements called evening elements that exist in promoters of ODO1 and other FVBP genes. Thus, our results imply that PhLHY directly sets the timing of floral volatile emission by restricting the expression of ODO1 and other FVBP genes to the evening in Petunia.

The potential role of B-function gene involved in floral development ...

African Journals Online (AJOL)

Camellia changii Ye, a rare and endangered species, has a phenotype that sepals frequently transform into petals. We assumed that this change would cause single C. changii Ye turned double flowers and this was confirmed by the double flowers we found in grafted C. changii Ye. The microstructure of floral organs ...

Floral to green: mating switches moth olfactory coding and preference.

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Saveer, Ahmed M; Kromann, Sophie H; Birgersson, Göran; Bengtsson, Marie; Lindblom, Tobias; Balkenius, Anna; Hansson, Bill S; Witzgall, Peter; Becher, Paul G; Ignell, Rickard

2012-06-22

Mating induces profound physiological changes in a wide range of insects, leading to behavioural adjustments to match the internal state of the animal. Here, we show for the first time, to our knowledge, that a noctuid moth switches its olfactory response from food to egg-laying cues following mating. Unmated females of the cotton leafworm (Spodoptera littoralis) are strongly attracted to lilac flowers (Syringa vulgaris). After mating, attraction to floral odour is abolished and the females fly instead to green-leaf odour of the larval host plant cotton, Gossypium hirsutum. This behavioural switch is owing to a marked change in the olfactory representation of floral and green odours in the primary olfactory centre, the antennal lobe (AL). Calcium imaging, using authentic and synthetic odours, shows that the ensemble of AL glomeruli dedicated to either lilac or cotton odour is selectively up- and downregulated in response to mating. A clear-cut behavioural modulation as a function of mating is a useful substrate for studies of the neural mechanisms underlying behavioural decisions. Modulation of odour-driven behaviour through concerted regulation of odour maps contributes to our understanding of state-dependent choice and host shifts in insect herbivores.

Identification and cloning of class II and III chitinases from alkaline floral nectar of Rhododendron irroratum, Ericaceae.

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Zha, Hong-Guang; Milne, Richard I; Zhou, Hong-Xia; Chen, Xiang-Yang; Sun, Hang

2016-10-01

Class II and III chitinases belonging to different glycoside hydrolase families were major nectarins in Rhododendron irroratum floral nectar which showed significant chitinolytic activity. Previous studies have demonstrated antimicrobial activity in plant floral nectar, but the molecular basis for the mechanism is still poorly understood. Two chitinases, class II (Rhchi2) and III (Rhchi3), were characterized from alkaline Rhododendron irroratum nectar by both SDS-PAGE and mass spectrometry. Rhchi2 (27 kDa) and Rhchi3 (29 kDa) are glycoside hydrolases (family 19 and 18) with theoretical pI of 8.19 and 7.04. The expression patterns of Rhchi2 and Rhchi3 were analyzed by semi-quantitative RT-PCR. Rhchi2 is expressed in flowers (corolla nectar pouches) and leaves while Rhchi3 is expressed in flowers. Chitinase in concentrated protein and fresh nectar samples was visualised by SDS-PAGE and chitinolytic activity in fresh nectar was determined spectrophotometrically via chitin-azure. Full length gene sequences were cloned with Tail-PCR and RACE. The amino acid sequence deduced from the coding region for these proteins showed high identity with known chitinases and predicted to be located in extracellular space. Fresh R. irroratum floral nectar showed significant chitinolytic activity. Our results demonstrate that class III chitinase (GH 18 family) also exists in floral nectar. The functional relationship between class II and III chitinases and the role of these pathogenesis-related proteins in antimicrobial activity in nectar is suggested.

Evaluación de preservantes florales en la poscosecha de tres variedades de clavel estándar

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López Paola

2008-04-01

Full Text Available

En clavel es imprescindible el tratamiento poscosecha a base de tiosulfato de plata (STS, para garantizar una mayor longevidad floral; sin embargo, los tratamientos antietilénicos a base del ión plata implican contaminación ambiental. El objetivo de este estudio fue realizar la evaluación de diferentes compuestos en la poscosecha de clavel estándar variedades Nelson, Dream y Delphi, como posibles sustitutos del STS. Para este fin, se utilizaron tratamientos a base de STS, SR-AOA (ácido aminooxacético de liberación lenta y quitosan. En seguida a la cosecha de los tallos florales se realizó una simulación de viaje con una duración aproximada de 21 días; posteriormente, las flores fueron sometidas a evaluaciones de longevidad, velocidad de apertura, color y consumo de agua. En la evolución de la vida en florero, se observó la misma tendencia para las tres variedades: un primer grupo de mayor longevidad floral, conformado por los tratamientos a base de SR-AOA y STS, con un promedio de durabilidad de 14 a 20 días; y el segundo grupo, de menor longevidad floral, conformado por los tratamientos a base de quitosan, quitosan más ácido cítrico, quitosan más AOA y testigo absoluto, con una duración promedio de 6 a 8 días.

Tipos polínicos encontrados em colônias de abelhas africanizadas sujeitas à doença cria ensacada brasileira Pollen types found in africanized honeybees colonies submitted to brazilian sac brood disease

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Marta Rodrigues Pacheco

2009-10-01

Full Text Available O pólen de algumas espécies de Stryphnodendron (Mimosoidea, conhecidas popularmente por barbatimão, tem sido apontado como agente causador da mortandade de larvas pré-pupas observada na cria ensacada brasileira (CEB. Neste estudo, objetivou-se identificar os tipos polínicos encontrados em amostras de pólen coletadas em colméias de Apis mellifera L., no Estado do Rio de Janeiro, a fim de elucidar as fontes florais utilizadas por essa espécie de abelhas em períodos sujeitos a CEB, com especial atenção para a presença do pólen de Stryphnodendron spp. Foram coletadas amostras de pólen apícola e pão de abelhas em sete apiários, em três municípios do Estado do Rio de Janeiro. A amostragem foi tomada um mês antes e durante a ocorrência da CEB. As famílias botânicas mais representativas foram: Leguminosae, Euphorbiaceae, Asteraceae, Poaceae e Myrtaceae. O pólen de Stryphnodendron não esteve presente nas amostras analisadas. A ausência de Stryphnodendron no menu floral das colônias africanizadas acometidas pela CEB em condições naturais sugere outro fator causal para a CEB no Estado do Rio de Janeiro.The pollen of some Stryphnodendron species (Mimosoidea, commonly known as barbatimão, has been identified as a causative agent of pre-pulps larvae mortality, observed in Brazilian sac brood disease (BSB. The goal of this study is to identify the pollen types found in samples of pollen collected by Apis mellifera L. to elucidate the floral diet used by this honeybee specie in Rio de Janeiro state during the periods where BSB usually occurs. Particular attention was given to the pollen of Stryphnodendron spp presence. Samples of pollen and bee bread were collected from seven apiaries located in Rio de Janeiro state, Brazil. Sampling procedures were done a month before BSB usual occurrence and also during its occurrence. Leguminosae, Euphorbiaceae, Asteraceae, Poaceae and Myrtaceae were most representative botanical families on

Viability and infectivity analysis of Toxoplasma gondii under axenic conditions = Análise da viabilidade e infectividade de taquizoítas de Toxoplasma gondii em condições axênicas

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Ferreira-da-Silva, Marialice Fonseca

2010-01-01

Conclusões: nossos dados abrem novas perspectivas para o estudo de diferentes aspectos da biologia do Toxoplasma gondii, incluindo mecanismos de nutrição, ensaios experimentais de drogas in vitro, ou estudos da biologia celular e molecular diretamente sobre o parasito

Notes on the nesting biology of five species of Euglossini (Hymenoptera: Apidae in the Brazilian Amazon

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Fernando Carvalho-Filho

2017-04-01

Resumo. As abelhas-da-orquídea (Euglossini possuem tamanho médio a grande, corpo parcialmente ou completamente metálico e são relativamente comuns na região Neotropical. Apesar disso, a biologia de nidificação da maioria das espécies permanece desconhecida. Portanto, o objetivo deste estudo e fornecer novas informações sobre a biologia de nidificação de cinco espécies de Euglossini encontradas em área urbana e florestada da Amazônia Brasileira. Os ninhos de Eufriesea pulchra (Smithe Euglossa chalybeata Frieseforam registrados pela primeira vez, encontrados dentro de ninho de formiga Azteca sp. e em uma árvore apodrecida caída, respectivamente. O ninho de Euglossa townsendiCockerell foi registrado pela primeira vez em uma folha da planta ornamental Cordyline sp. (Asparagaceae. Euglossa intersecta Latreillefoi registrada nidificando dentro de um ninho abandonado de cupim e Euglossa cordata (Linnaeusfoi encontrada nidificando em uma maçaneta tubular de metal de uma janela.

Floral morphology and morphogenesis in Camptotheca (Nyssaceae), and its systematic significance.

Science.gov (United States)

Gong, Jing-Zhi; Li, Qiu-Jie; Wang, Xi; Ma, Yue-Ping; Zhang, Xiao-Hui; Zhao, Liang; Chang, Zhao-Yang; Ronse De Craene, Louis

2018-03-22

Camptotheca is endemic to China and there are limited data about the breeding system and morphogenesis of the flowers. Camptotheca is thought to be related to Nyssa and Davidia in Nyssaceae, which has sometimes been included in Cornaceae. However, molecular phylogenetic studies confirmed the inclusion of Camptotheca in Nyssaceae and its exclusion from Cornaceae. The aim of this study was to reveal developmental features of the inflorescence and flowers in Camptotheca to compare with related taxa in Cornales. Inflorescences and flowers of Camptotheca acuminata at all developmental stages were collected and studied with a scanning electron microscope and stereo microscope. Camptotheca has botryoids which are composed of several capitate floral units (FUs) that are initiated acropetally. On each FU, flowers are grouped in dyads that are initiated acropetally. All floral organs are initiated centripetally. Calyx lobes are restricted to five teeth. The hypanthium, with five toothed calyx lobes, is adnate to the ovary. The five petals are free and valvate. Ten stamens are inserted in two whorls around the central depression, in which the style is immersed. Three carpels are initiated independently but the ovary is syncarpous and unilocular. The ovule is unitegmic and heterotropous. Inflorescences are functionally andromonoecious varying with the position of the FUs on the inflorescence system. Flowers on the upper FU often have robust styles and fully developed ovules. Flowers on the lower FU have undeveloped styles and aborted ovules, and the flowers on the middle FU are transitional. Camptotheca possesses several traits that unify it with Nyssa, Mastixia and Diplopanax. Inflorescence and floral characters support a close relationship with Nyssaceae and Mastixiaceae but a distant relationship with Cornus. Our results corroborate molecular inferences and support a separate family Nyssaceae.

Floral Benzenoid Carboxyl Methyltransferases: From in Vitro to in Planta Function

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Effmert,U.; Saschenbrecker, S.; Ross, J.; Negre, F.; Fraser, C.; Noel, J.; Dudareva, N.; Piechulla, B.

2005-01-01

Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT's three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in plants depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses

Effect of floral bud reduction on flower longevity in Asiatic hybrids lilies.

NARCIS (Netherlands)

Meulen-Muisers, van der J.J.M.; Oeveren, van J.C.; Sandbrink, J.M.; Tuyl, van J.M.

1995-01-01

Floral bud abortion was found to be an undesirable source of non-genetic variation in breeding trials directed on the improvement of individual flower longevity in Asiatic hybrid lilies. It increased the longevity of the remaining flowers of the inflorescence. A similar response was found after

Molecular evolution and patterns of duplication in the SEP/AGL6-like lineage of the Zingiberales: a proposed mechanism for floral diversification.

Science.gov (United States)

Yockteng, Roxana; Almeida, Ana M R; Morioka, Kelsie; Alvarez-Buylla, Elena R; Specht, Chelsea D

2013-11-01

The diversity of floral forms in the plant order Zingiberales has evolved through alterations in floral organ morphology. One striking alteration is the shift from fertile, filamentous stamens to sterile, laminar (petaloid) organs in the stamen whorls, attributed to specific pollination syndromes. Here, we examine the role of the SEPALLATA (SEP) genes, known to be important in regulatory networks underlying floral development and organ identity, in the evolution of development of the diverse floral organs phenotypes in the Zingiberales. Phylogenetic analyses show that the SEP-like genes have undergone several duplication events giving rise to multiple copies. Selection tests on the SEP-like genes indicate that the two copies of SEP3 have mostly evolved under balancing selection, probably due to strong functional restrictions as a result of their critical role in floral organ specification. In contrast, the two LOFSEP copies have undergone differential positive selection, indicating neofunctionalization. Reverse transcriptase-polymerase chain reaction, gene expression from RNA-seq data, and in situ hybridization analyses show that the recovered genes have differential expression patterns across the various whorls and organ types found in the Zingiberales. Our data also suggest that AGL6, sister to the SEP-like genes, may play an important role in stamen morphology in the Zingiberales. Thus, the SEP-like genes are likely to be involved in some of the unique morphogenetic patterns of floral organ development found among this diverse order of tropical monocots. This work contributes to a growing body of knowledge focused on understanding the role of gene duplications and the evolution of entire gene networks in the evolution of flower development.

Floral thermogenesis of three species of Hydnora (Hydnoraceae) in Africa.

Science.gov (United States)

Seymour, Roger S; Maass, Erika; Bolin, Jay F

2009-10-01

Floral thermogenesis occurs in at least 12 families of ancient seed plants. Some species show very high rates of respiration through the alternative pathway, and some are thermoregulatory, with increasing respiration at decreasing ambient temperature. This study assesses the intensity and regulation of respiration in three species of African Hydnora that represent the Hydnoraceae, an unusual family of holoparasitic plants from arid environments. Long-term respirometry (CO(2) production) and thermometry were carried out on intact flowers of H. africana, H. abyssinica and H. esculenta in the field, and short-term measurements were made on floral parts during the protogynous flowering sequence. For H. africana, there was no temperature elevation in either the osmophores or the gynoecial chamber in any phase, and mass-specific respiration rates of the flower parts were low (maximum 8.3 nmol CO(2) g(-1) s(-1) in osmophore tissue). Respiration tracked ambient and floral temperatures, eliminating the possibility of the inverse relationship expected in thermoregulatory flowers. Hydnora abyssinica flowers had higher respiration (maximum 27.5 nmol g(-1) s(-1) in the osmophores) and a slight elevation of osmophore temperature (maximum 2.8 degrees C) in the female stage. Respiration by gynoecial tissue was similar to that of osmophores in both species, but there was no measurable elevation of gynoecial chamber temperature. Gynoecial chamber temperature of H. esculenta could reach 3.8 degrees C above ambient, but there are no respiration data available. Antheral tissue respiration was maximal in the male phase (4.8 nmol g(-1) s(-1) in H. africana and 10.3 nmol g(-1) s(-1) in H. abyssinica), but it did not raise the antheral ring temperature, which showed that thermogenesis is not a by-product of pollen maturation or release. The exceptionally low thermogenesis in Hydnora appears to be associated with scent production and possibly gynoecial development, but has little direct

Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

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Peter eTóth

2016-03-01

Full Text Available The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae, are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs, consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae.

Study on the Development of Yunnan Floral E-commerce

OpenAIRE

Kuang, Yulan; Li, Qifang; Ning, Wangyun

2013-01-01

Cut flower production in Yunnan accounts for 80% nationwide. In order to expand the Yunnan Flower sales channels, the promotion of the development of e-commerce is necessary. In 2012 China's online shopping users reached 247 million people, but e-commerce of fresh flowers lagged behind due to the constraints of preservation facilities and logistics cost. The analysis of the factors restricting the development of floral e-commerce and the proposition of solutions to this problem can promote fa...

Petunia × hybrida floral scent production is negatively affected by high-temperature growth conditions.

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Cna'ani, Alon; Mühlemann, Joelle K; Ravid, Jasmin; Masci, Tania; Klempien, Antje; Nguyen, Thuong T H; Dudareva, Natalia; Pichersky, Eran; Vainstein, Alexander

2015-07-01

Increasing temperatures due to changing global climate are interfering with plant-pollinator mutualism, an interaction facilitated mainly by floral colour and scent. Gas chromatography-mass spectroscopy analyses revealed that increasing ambient temperature leads to a decrease in phenylpropanoid-based floral scent production in two Petunia × hybrida varieties, P720 and Blue Spark, acclimated at 22/16 or 28/22 °C (day/night). This decrease could be attributed to down-regulation of scent-related structural gene expression from both phenylpropanoid and shikimate pathways, and up-regulation of a negative regulator of scent production, emission of benzenoids V (EOBV). To test whether the negative effect of increased temperature on scent production can be reduced in flowers with enhanced metabolic flow in the phenylpropanoid pathway, we analysed floral volatile production by transgenic 'Blue Spark' plants overexpressing CaMV 35S-driven Arabidopsis thaliana production of anthocyanin pigments 1 (PAP1) under elevated versus standard temperature conditions. Flowers of 35S:PAP1 transgenic plants produced the same or even higher levels of volatiles when exposed to a long-term high-temperature regime. This phenotype was also evident when analysing relevant gene expression as inferred from sequencing the transcriptome of 35S:PAP1 transgenic flowers under the two temperature regimes. Thus, up-regulation of transcription might negate the adverse effects of temperature on scent production. © 2014 John Wiley & Sons Ltd.

Biologia de Lutzomyia intermedia (Lutz & Neiva, 1912 e Lutzomyia longipalpis (Lutz & Neiva, 1912 (Diptera, Psychodidae em condições experimentais: II. Influência de fatores ambientais no comportamento das formas imaturas e adultas Biology of Lutzomyia intermedia (Lutz & Neiva, 1912 and Lutzomyia longipalpis (Lutz & Neiva, 1912 (Diptera, Psychodidae in experimental conditions: II. Influence of environmental factors in the behavior of immature stages and adults

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Elizabeth F. Rangel

1987-09-01

Full Text Available Com o objetivo de ampliar os conheciemntos sobre a biologia de Lutzomyia intermedia e Lutzomya longipalpis, mantidos em colônias autônomas no laboratório, apresentamos dados referentes a alterações em seu comportamento determinadas por influência de fatores ambientais. L. longipalpis foi mais fácil de criar, mais produtiva e mais resitente ás variações das condições ambientais; suga a qualquer hora do dia, enquanto que L. intermedia prefere fazê-lo ao crepúsculo e à noite, quando também ocorrem masi freqüentemente as desovas e as ecdises dos adultos das duas espécies. As fases imaturas de ambas as espécies resistem à imersão na água por até 1 hora e a baixa temperatura de 5ºC por até 6 horas.Proceeding on our studies on the biology of Lutzomyia intermedia and Lutzomyia longipalpis in closed colonies in the laboratory, we here present our observations on changes in their behavior caused by environmental conditions. L. longipaldis was easier to breed, more productive and more resistant to environmental changes; it feeds at any time of the day or night, while L. intermedia prefers to do it at sunset and at night, the preferencial time for oviposition and ecdysis of adults of both species. The immature stages of both species resisted to immersion in water for up to 1 hour and low temperature (5ºC for 1 to 6 hours.

Teaching Flower Structure & Floral Formulae--A Mix of the Real & Virtual Worlds

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Burrows, Geoff

2010-01-01

The study of flower structure is essential in plant identification and in understanding sexual reproduction in plants, pollination syndromes, plant breeding, and fruit structure. Thus, study of flower structure and construction of floral formulae are standard parts of first-year university botany and biology courses. These activities involve…

A sexually dimorphic corolla appendage affects pollen removal and floral longevity in gynodioecious Cyananthus delavayi (Campanulaceae.

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Yang Niu

Full Text Available The floral traits of bisexual flowers may evolve in response to selection on both male and female functions, but the relative importance of selection associated with each of these two aspects is poorly resolved. Sexually dimorphic traits in plants with unisexual flowers may reflect gender-specific selection, providing opportunities for gaining an increased understanding of the evolution of specific floral traits. We examined sexually dimorphic patterns of floral traits in perfect and female flowers of the gynodioecious species Cyananthus delavayi. A special corolla appendage, the throat hair, was investigated experimentally to examine its influences on male and female function. We found that perfect flowers have larger corollas and much longer throat hairs than female flowers, while female ones have much exerted stigmas. The presence of throat hairs prolonged the duration of pollen presentation by restricting the amount of pollen removed by pollen-collecting bees during each visit. Floral longevity was negatively related to the rate of pollen removal. When pollen removal rate was limited in perfect flowers, the duration of the female phases diminished with the increased male phase duration. There was a weak negative correlation between throat hair length and seed number per fruit in female flowers, but this correlation was not significant in perfect flowers. These results suggest that throat hairs may enhance male function in terms of prolonged pollen presentation. However, throat hairs have no obvious effect on female function in terms of seed number per fruit. The marked sexual dimorphism of this corolla appendage in C. delavayi is likely to have evolved and been maintained by gender-specific selection.

Adesão, proliferação e migração de células de astrocitoma humano U-87 em fibronectina, laminina e colágeno IV e a expressão e organização de vimentina e GFAP

OpenAIRE

Garcez, Ricardo Castilho

2004-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Neurociências O microambiente extracelular é capaz de modular a organização e expressão dos filamentos intermediários (vimentina, GFAP) durante os processos de adesão, proliferação, migração e diferenciação celular. A elucidação destes mecanismos é de relevante importância no estudo da biologia de células normais e tumorais. O presente trabalho visa compreender o env...

Reproductive biology of Palythoa caribaeorum and Protopalythoa variabilis (Cnidaria, Anthozoa, Zoanthidea from the southeastern coast of Brazil Biologia reprodutiva de Palythoa caribaeorum e Protopalythoa variabilis (Cnidaria: Anthozoa: Zoanthidea da costa sudeste do Brasil

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H. K. Boscolo

2005-02-01

Full Text Available The reproductive biology of Palythoa caribaeorum (Duchassaing & Michelotti 1860 and Protopalythoa variabilis (Duerden 1898 was studied through monthly samples from tagged colonies from June 1996 to June 1997, in São Sebastião channel, São Paulo, Brazil (45º26'W, 23º50'S. The gametogenesis was similar to that of other zoanthids as shown by histological preparations. Oocyte diameters and maturation stages of testis vesicles were evaluated on squash preparations. Both species showed sequential protogynic hermaphroditism, with high frequency of fertile polyps (83% in P. variabilis and 72% in P. caribaeorum, high frequency of colonies in female sex condition (65.3% of P. variabilis and 41.7% of P. caribaeorum, and apparently continuous gametogenesis. In P. caribaeorum, egg release was continuous and sperm release took place during half of the analyzed period. In P. variabilis, egg and sperm release occurred in April-May and February-March 1997, respectively.A biologia reprodutiva de Palythoa caribaeorum (Duchassaing & Michelotti 1860 e Protopalythoa variabilis (Duerden 1898 foi estudada por amostras mensais de colônias etiquetadas de junho de 1996 a junho de 1997, no canal de São Sebastião, São Paulo, Brasil (45º26'W, 23º50'S. A gametogênese apresentou-se semelhante à de outros zoantídeos, como evidenciado em preparações histológicas. O diâmetro dos oócitos e os estágios de maturação dos folículos testiculares foram avaliados por preparações do tipo "squash". Ambas as espécies mostraram hermafroditismo seqüencial protogínico, com alta freqüência de pólipos férteis (83% em P. variabilis e 72% em P. caribaeorum e de colônias na condição sexual feminina (65,3% para P. variabilis e 41,7% para P. caribaeorum, e, aparentemente, gametogênese contínua. Em P. caribaeorum, a liberação de oócitos foi contínua e a liberação de espermatozóides ocorreu durante metade do período analisado. Para P. variabilis, a libera

Biologia da polinização e sistema reprodutivo de Psychotria barbiflora DC. (Rubiaceae Pollination biology and breeding system of Psychotria barbiflora DC. (Rubiaceae

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Luciana Almeida Gomes Teixeira

2004-12-01

Full Text Available O estudo foi realizado no período de abril/1999 a setembro/2000, no Parque Estadual Dois Irmãos, Recife (PE Brasil, um remanescente de floresta Atlântica. Psychotria barbiflora é espécie subarbustiva (0,5-2,0m alt., com período de floração entre abril e julho e frutificação de junho a setembro. A espécie apresentou heterostilia do tipo distilia, com inflorescências terminais, pendentes, envoltas por brácteas que apresentaram coloração esverdeada durante a floração e tornaram-se arroxeadas na fase de frutificação. As flores abriram por volta das 4h30min e duraram até às 13h. O volume médio de néctar foi ca. 0,8 e 0,6µl e a concentração de açúcares, aproximadamente 22 e 24%, nas flores longistilas e brevistilas, respectivamente. Os morfos florais apresentaram semelhança em relação ao tamanho da corola, entretanto nas flores brevistilas os grãos de pólen foram maiores e em menor quantidade quando comparado com as flores longistilas. Psychotria barbiflora é melitófila, sendo polinizada por três espécies de abelhas, as quais coletaram néctar e pólen, e por uma espécie de vespa que coletou apenas néctar, em ambos os morfos florais. Baseando-se nos resultados das polinizações manuais e no crescimento dos tubos polínicos, pode-se concluir que esta espécie apresenta auto-incompatibilidade do tipo esporofítica, com formação de frutos apenas nos cruzamentos intermorfos.The reproductive biology of Psychotria barbiflora was investigated from April/1999 to September/2000, in the Dois Irmãos State Park, Recife, Pernambuco State, Brazil, an Atlantic Forest remnant. Psychotria barbiflora is a understory species (0.5-2.0m tall, which flowered between April and July and fruiting from June to September. The species presented heterostyly (distyly, and the flowers are arranged in terminal, pendant inflorescences, wrapped in bracts, which are greenish during the flowering period and become purple during the fruiting

T-DNA transfer and T-DNA integration efficiencies upon Arabidopsis thaliana root explant cocultivation and floral dip transformation.

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Ghedira, Rim; De Buck, Sylvie; Van Ex, Frédéric; Angenon, Geert; Depicker, Ann

2013-12-01

T-DNA transfer and integration frequencies during Agrobacterium-mediated root explant cocultivation and floral dip transformations of Arabidopsis thaliana were analyzed with and without selection for transformation-competent cells. Based on the presence or absence of CRE recombinase activity without or with the CRE T-DNA being integrated, transient expression versus stable transformation was differentiated. During root explant cocultivation, continuous light enhanced the number of plant cells competent for interaction with Agrobacterium and thus the number of transient gene expression events. However, in transformation competent plant cells, continuous light did not further enhance cotransfer or cointegration frequencies. Upon selection for root transformants expressing a first T-DNA, 43-69 % of these transformants showed cotransfer of another non-selected T-DNA in two different light regimes. However, integration of the non-selected cotransferred T-DNA occurred only in 19-46 % of these transformants, indicating that T-DNA integration in regenerating root cells limits the transformation frequencies. After floral dip transformation, transient T-DNA expression without integration could not be detected, while stable T-DNA transformation occurred in 0.5-1.3 % of the T1 seedlings. Upon selection for floral dip transformants with a first T-DNA, 8-34 % of the transformants showed cotransfer of the other non-selected T-DNA and in 93-100 % of them, the T-DNA was also integrated. Therefore, a productive interaction between the agrobacteria and the female gametophyte, rather than the T-DNA integration process, restricts the floral dip transformation frequencies.

Pollination ecology and floral function of Brown’s peony (Paeonia brownii in the Blue Mountains of northeastern Oregon

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Nan Vance

2013-03-01

Full Text Available Brown’s peony, Paeonia brownii (Paeoniaceae, is one of only two peony species native to the Western Hemisphere, yet its pollination ecology and breeding system have never been documented. Using flowering individuals of an endemic colony in the Blue Mountains of Oregon, U.S., we investigated the peony’s pollination system and floral function. We also examined pollen/carpel interactions through experimental pollinations aided by fluorescence microscopy. Paeonia brownii appears to be self compatible and mostly protogynous with floral traits of a generalist pollination system. The flowers appear to attract insects by producing abundant floral nectar secreted from lobes of a perigynous disc throughout their 9-15-days of anthesis. The most common pollen vectors were wasp queens (Vespidae, the large flower fly Criorhina caudata (Syrphidae, and females of Lasioglossum spp. (Halictidae, all of which foraged exclusively for nectar. Whether collected from foraging wasps and flies, anthers, or stigmas, about half the pollen grains appeared fertile. The number of ovules per carpel was about 19. Seed set (seeds/ovule of naturally pollinated flowers was about 20% with about 4 viable seeds per follicle. The number of fertile pollen grains transferred to the stigma under natural conditions was highly variable but generally low, which may have contributed in part to the low rate of seed set. This study raises further questions about the role of pollen sterility, floral nectar and vespid wasps in shaping a pollinator system that is unusual in Paeonia.

Variação temporal e espacial na dieta de Trachelyopterus galeatus (Siluriformes, Auchenipteridae em dois reservatórios no semiárido Neotropical

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José I. M. Sousa

2017-11-01

Full Text Available RESUMO Alimentação de peixes propicia dados para discussão de aspectos teóricos atendendo a propósitos como o conhecimento básico da biologia de uma determinada espécie através do entendimento da organização trófica em um determinado ambiente. Assim, objetivou-se analisar a composição alimentar e a morfologia, associadas ao hábito alimentar de Trachelyopterus galeatus (Linnaeus, 1766 e avaliar as alterações da dieta ao longo do tempo. As coletas dos indivíduos ocorreram trimestralmente, durante os meses de fevereiro, maio, agosto e novembro de 2013, por meio de redes de esperas com diferentes malhas distribuídas em oito pontos no reservatório de Santa Cruz e em cinco pontos no reservatório de Umari, ambos localizados no Rio Grande do Norte. Dos itens identificados da dieta foram obtidas as frequências de ocorrência e volumétrica, combinadas no cálculo de Índice Alimentar (IAi. Os volumes dos itens foram ordenados em NMDS e as suas diferenças testadas em PERMANOVA, a contribuição de cada item alimentar para as diferenças entre os reservatórios foi avaliada através da análise SIMPER. As análises dos conteúdos alimentares permitiram a classificação da espécie como carnívora, constatando-se significativas alterações temporais em sua dieta, com as características morfológicas em conformidade ao consumo dos itens alimentares.

Floral evolution of Philodendron subgenus Meconostigma (Araceae.

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Letícia Loss de Oliveira

Full Text Available Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK and two nuclear (ETS and 18S markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

Floral evolution of Philodendron subgenus Meconostigma (Araceae).

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de Oliveira, Letícia Loss; Calazans, Luana Silva Braucks; de Morais, Érica Barroso; Mayo, Simon Joseph; Schrago, Carlos Guerra; Sakuragui, Cassia Mônica

2014-01-01

Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

Período reprodutivo de fêmeas de Hypostomus commersoni Valenciennes, 1836, em uma barragem na bacia do rio Uruguai

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Rita Cristina Gomes Galarça

2014-03-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2014v27n2p87 O cascudo Hypostomus commersoni, nativo da Bacia do Rio Uruguai, pertencente à família Loricariidae, é encontrado habitualmente em ambientes lênticos e tem sua biologia ainda pouco conhecida na região do Pampa Brasileiro. Foi verificado o período reprodutivo pela análise da variação mensal do índice gonadossomático (IGS, do índice hepatossomático (IHS, e o fator de condição gonadal (∆K, além da observação macroscópica do estádio de desenvolvimento gonadal. Após a análise dos resultados pode se concluir que a espécie em estudo tem seu período reprodutivo de setembro estendendo-se a janeiro, atingindo seu pico de reprodução em novembro. Os indicadores IHS e ∆K apresentaram-se mais elevados no mês de outubro, demonstrando uma melhor condição gonadal e o IHS revelou um acúmulo de reservas lipídicas para fornecer energia na vitelogênese, no mês antecedente ao pico de reprodução, sendo desta forma, bons indicadores que corroboram com o período de reprodução determinado.

VALIDACIÓN DE MODELOS DE PREDICCIÓN DEL DESARROLLO FLORAL DEL AGUACATE 'HASS' DESARROLLADOS PARA NAYARIT, EN VARIOS CLIMAS DE MICHOACÁN

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S. Salazar-García

2009-01-01

Full Text Available Utilizando registros de temperatura ambiental y desarrollo floral obtenidos de 1998 al 2006 de una zona con clima semicálido subhúmedo del estado de Nayarit, se desarrollaron cinco modelos de predicción del desarrollo floral para brotes de los flujos vegetativos de invierno y verano de aguacate "Hass". El objetivo de esta investigación fue evaluar los modelos de predicción generados en Nayarit, para estimar capacidad para predecir el desarrollo floral de brotes de los flujos vegetativos de invierno, primavera y verano de "Hass" en los principales climas de la región aguacatera del estado de Michoacán. El modelo de predicción veranoDFA¿19 desarrollado en Nayarit, mostró una elevada capacidad de predicción del desarrollo floral en brotes del flujo de verano (R2 = 0.94, para un conjunto de datos de los cuatro climas del estado de Michoacán en donde se concentra el 85 % de la superficie aguacatera: cálido subhúmedo Aw1(w, semicálido subhúmedo (AC(w0(w, semicálido subhúmedo (AC(w1(w + (AC(w2(w y templado subhúmedo C(w2(w. Los demás modelos de predicción probados en Michoacán no pronosticaron el desarrollo floral en brotes de los flujos vegetativos de invierno, primavera o verano en ninguno de los climas estudiados.

SEP-class genes in Prunus mume and their likely role in floral organ development.

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Zhou, Yuzhen; Xu, Zongda; Yong, Xue; Ahmad, Sagheer; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

2017-01-13

Flower phylogenetics and genetically controlled development have been revolutionised during the last two decades. However, some of these evolutionary aspects are still debatable. MADS-box genes are known to play essential role in specifying the floral organogenesis and differentiation in numerous model plants like Petunia hybrida, Arabidopsis thaliana and Antirrhinum majus. SEPALLATA (SEP) genes, belonging to the MADS-box gene family, are members of the ABCDE and quartet models of floral organ development and play a vital role in flower development. However, few studies of the genes in Prunus mume have yet been conducted. In this study, we cloned four PmSEPs and investigated their phylogenetic relationship with other species. Expression pattern analyses and yeast two-hybrid assays of these four genes indicated their involvement in the floral organogenesis with PmSEP4 specifically related to specification of the prolificated flowers in P. mume. It was observed that the flower meristem was specified by PmSEP1 and PmSEP4, the sepal by PmSEP1 and PmSEP4, petals by PmSEP2 and PmSEP3, stamens by PmSEP2 and PmSEP3 and pistils by PmSEP2 and PmSEP3. With the above in mind, flower development in P. mume might be due to an expression of SEP genes. Our findings can provide a foundation for further investigations of the transcriptional factors governing flower development, their molecular mechanisms and genetic basis.

Phenological cycle and floral development of Chloraea crispa (Orchidaceae)

OpenAIRE

Steinfort, Ursula; Cisternas, Mauricio A; García, Rolando; Vogel, Hermine; Verdugo, Gabriela

2012-01-01

Chloraea crispa Lindl. is a terrestrial orchid endemic to Chile that has potential to be a novel alternative for the cut flower industry. The objectives of this study were to describe the phenological cycle and floral bud development of C. crispa to determine the timing of initiation and differentiation of the spike. During the summer, plants are dormant. The renewal buds are located at the top of the rhizome, next to the buds from which the shoot of the previous season originated. From the e...

Especiação e seus mecanismos: histórico conceitual e avanços recentes

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Eduardo Colley

2013-12-01

Full Text Available Apresenta uma abordagem histórica sobre conceitos gerais de especiação e seus mecanismos, a partir das ideias primordiais até as teorias mais recentes que visam elucidar a origem da biodiversidade. Sabe-se que especiação é um tema polêmico e complexo que abrange praticamente todas as linhas de pesquisa dentro da biologia, além da geologia e da paleontologia. O objetivo principal do artigo é clarificar os conceitos teóricos sobre a origem das espécies animais, na ordem cronológica em que foram estabelecidos, ao longo do desenvolvimento da biologia evolutiva como ciência.

[Analysis of the components of floral scent in Glochidion puberum using gas chromatography-mass spectrometry with dynamic headspace adsorption].

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Huang, Daihong; Zhang, Zhenguo; Chen, Guoping; Li, Houhun; Shi, Fuchen

2015-03-01

The floral scent plays the important key role in maintaining the obligate pollination mutualism between Glochidion plants and Epicephala moths. In the study, the dynamic headspace adsorption technique was employed to collect the floral scent emitted by Glochidion puberum, gas chromatography coupled with mass spectrometry (GC-MS) was used for the detection and identification of volatile chemical components in headspace samples of flowers from G. puberum. The peak area normalization was used to determine the relative contents of each odour component. The results showed that 45 compounds mainly consisting of monoterpenes and sesquiterpenes were isolated from the floral scent produced by G. puberum. Especially, both linalool (38.06%) and β-elemene (23.84%) were considered as the major scent components of G. puberum. It was speculated that linalool and β-elemene may be the two potential compounds attracting female Epicephala moths. The study provided the basic data for further electroantennographic detection and bioassays to identify the compounds having the actual physiological activity to female Epicephala moths.

Regeneration and transformation of Eucalyptus grandis

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Esteki, Leila

2013-01-01

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas Eucalyptus grandis is the most widely used species in planted forests in tropical and subtropical areas. The traits of interest underlying Eucalyptus breeding programs concern productivity and wood quality for the pulp and paper industry, as well as biotic and abiotic stress tolerance. The development of an efficient transformation protocol is necessary to explore eucalypt resources th...

Germinação de pólen e aplicação de ácido bórico em botões florais de nespereiras

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Paulyene Vieira Nogueira

2015-03-01

Full Text Available O objetivo do trabalho foi estabelecer meio de cultura e avaliar a germinação de grãos de pólen in vitro e após a aplicação de boro na panícula em cultivares de nespereira. Foi determinado o meio de cultura ideal para germinação dos grãos de pólen e avaliada a porcentagem de germinação utilizando pólen da cultivar Mizauto. Também avaliou-se o melhor estágio de desenvolvimento floral e horário do dia para coleta do pólen, bem como o tempo de incubação para sua germinação. Após estabelecido o meio, foi determinada a germinação de nove cultivares: Mizauto, Mizuho, Fukuhara, Parmogi, Centenária, Kurisaki, Néctar de Cristal, Mizumo e Precoce de Campinas. Em campo, avaliou-se a aplicação de ácido bórico em panículas de nespereiras Mizauto, nas concentrações 600 mg L–1, 1.200 mg L–1 e 1.800 mg L–1, além do controle sem aplicação. O meio de cultura estabelecido foi de 200 g L–1 de sacarose, 1.200 mg L–1 de ácido bórico, solidificado com 10 g L–1 de agar e pH 6, incubado por sete horas. O melhor estágio do botão floral foi na pré-antese, coletado entre 14 e 18 horas. A aplicação de 900 mg L–1 de ácido bórico em campo elevou a germinação dos grãos de pólen para 57,68%.

Floral scent compounds of Amazonian Annonaceae species pollinated by small beetles and thrips.

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Jürgens, A; Webber, A C; Gottsberger, G

2000-11-01

Chemical analysis (GC-MS) yielded a total of 58 volatile compounds in the floral scents of six species of Annonaceae distributed in four genera (Xylopia, Anaxagorea, Duguetia, and Rollinia), Xylopia aromatica is pollinated principally by Thysanoptera and secondarily by small beetles (Nitidulidae and Staphylinidae), whereas the five other species were pollinated by Nitidulidae and Staphylinidae only. Although the six Annonaceae species attract a similar array of pollinator groups, the major constituents of their floral scents are of different biochemical origin. The fragrances of flowers of Anaxagorea brevipes and Anaxagorea dolichocarpa were dominated by esters of aliphatic acids (ethyl 2-methylbutanoate, ethyl 3-methylbutanoate), which were not detected in the other species. Monoterpenes (limonene, p-cymene, alpha-pinene) were the main scent compounds of Duguetia asterotricha, and naphthalene prevailed in the scent of Rollinia insignis flowers. The odors of X. aromatica and Xylopia benthamii flowers were dominated by high amounts of benzenoids (methylbenzoate, 2-phenylethyl alcohol).

Floral and reproductive biology of Alcantarea nahoumii (Bromeliaceae, a vulnerable endemic species of the Atlantic Forest

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Maria Josirene Souza Moreira Bastos

Full Text Available ABSTRACT Alcantarea nahoumii occurs exclusively in the state of Bahia, Brazil, and is classified as vulnerable due to deforestation and frequent fires in the region. Knowledge of floral and reproductive biology is fundamental to understanding ecological interactions, as well as the reproductive success of plant species. The objective of this study was to evaluate the floral and reproductive biology of A. nahoumii in an Atlantic Forest fragment with regard to phenology, pollen viability, stigma receptivity, pollination ecology and reproductive systems, all of which are important parameters for of the development of conservation strategies for the species. Anthesis is diurnal and heterogeneous, starting at 6:30 a.m. and lasting until 8:00 a.m. Highest germination percentages and greatest pollen tube lengths were obtained in BK culture medium. Histochemical tests revealed high pollen viability (89.71 %. Stigma receptivity occurred during anthesis and lasted for up to 24 hours after floral opening. Alcantarea nahoumii exhibited preferential allogamy and self-compatibility, and required a pollinator to production of viable seeds. Sixteen species of pollinators were observed visiting A. nahoumii, among which were five hummingbird species. Even though its reproductive system is efficient, this bromeliad remains threatened mainly due to habitat fragmentation caused by deforestation, burning and predatory extractivism.

Efeito da concentração de sacarose na germinação in vitro do pólen de cinco acessos de bacurizeiro (Platonia insignis MART.

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Valdomiro Aurélio Barbosa de Souza

2013-09-01

Full Text Available O bacurizeiro é uma das espécies fruteiras nativas de maior importância socioeconômica das regiões Norte e Meio-Norte do Brasil. No entanto, ainda há carência de conhecimentos científicos sobre a espécie, especialmente sobre sua biologia floral, mecanismos reprodutivos e viabilidade do pólen. O conhecimento sobre a viabilidade do pólen é fundamental para o melhoramento genético, especialmente quando se tem em mente a realização de hibridizações controladas. O objetivo deste trabalho foi avaliar o efeito da sacarose e de acessos na viabilidade do pólen de bacurizeiro por meio da germinação in vitro. Avaliaram-se cinco acessos (BGB 6, BGB 11, BGB 48, BGB 32 e BGB 16 de bacurizeiro combinados com um tratamento-controle, sem sacarose, e quatro concentrações de sacarose (5; 7,5; 10 e 20%, em delineamento inteiramente ao acaso, em arranjo fatorial 5 x 5, com oito repetições. Na maioria dos acessos, a germinação in vitro do pólen atingiu um máximo (71,1 e 63,0% entre as concentrações de sacarose de 9,4 e 9,7% e, a partir daí, caiu de forma drástica até atingir um percentual inferior a 10% de germinação na concentração de 20% de sacarose. Foram encontrados bons percentuais de germinação (entre 63,0 e 77,1% para todos os acessos, com exceção do acesso BGB 16, que não alcançou 50%.

Methylation effect on chalcone synthase gene expression determines anthocyanin pigmentation in floral tissues of two Oncidium orchid cultivars.

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Liu, Xiao-Jing; Chuang, Yao-Nung; Chiou, Chung-Yi; Chin, Dan-Chu; Shen, Fu-Quan; Yeh, Kai-Wun

2012-08-01

The anthocyanin-biosynthetic pathway was studied in flowers of Oncidium Gower Ramsey with yellow floral color and mosaic red anthocyanin in lip crests, sepals and petals, and compared with the anthocyanin biosynthesis in flowers of Oncidium Honey Dollp, a natural somatoclone derived from tissue culture of Gower Ramsey, with a yellow perianth without red anthocyanins in floral tissues. HPLC analysis revealed that the red anthocyanin in lip crests of the Gower Ramsey cultivar comprised peonidin-3-O-glucoside, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside, whereas Honey Dollp was devoid of anthocyanin compounds. Among the five anthocyanin-biosynthetic genes, OgCHS was actively expressed in lip crests of Gower Ramsey flowers, but no transcripts of OgCHS were detected in Honey Dollp floral tissues. Transient expression of OgCHS by bombardment confirmed that recovery of the OgCHS gene expression completed the anthocyanin pathway and produced anthocyanin compounds in lip crests of Honey Dollp flowers. Transcription factor genes regulating anthocyanin biosynthesis showed no distinctive differences in the expression level of OgMYB1, OgbHLH and OgWD40 between the two cultivars. A methylation assay revealed that the promoter of OgCHS was not methylated in Gower Ramsey, while a positive methylation effect was present in the upstream promoter region of OgCHS in Honey Dollp. Overall, our results suggest that the failure of anthocyanin accumulation in Honey Dollp floral tissues may be attributed to inactivation of the OgCHS gene resulting from the epigenetic methylation of 5'-upstream promoter region.

Assessing pollinators’ use of floral resource subsidies in agri-environment schemes: An illustration using Phacelia tanacetifolia and honeybees

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Rowan Sprague

2016-11-01

Full Text Available Background Honeybees (Apis mellifera L. are frequently used in agriculture for pollination services because of their abundance, generalist floral preferences, ease of management and hive transport. However, their populations are declining in many countries. Agri-Environment Schemes (AES are being implemented in agricultural systems to combat the decline in populations of pollinators and other insects. Despite AES being increasingly embedded in policy and budgets, scientific assessments of many of these schemes still are lacking, and only a few studies have examined the extent to which insect pollinators use the floral enhancements that are part of AES and on which floral components they feed (i.e., pollen and/or nectar. Methods In the present work, we used a combination of observations on honeybee foraging for nectar/pollen from the Californian annual plant Phacelia tanacetifolia in the field, collection of pollen pellets from hives, and pollen identification, to assess the value of adding phacelia to an agro-ecosystem to benefit honeybees. Results It was found that phacelia pollen was almost never taken by honeybees. The work here demonstrates that honeybees may not use the floral enhancements added to a landscape as expected and points to the need for more careful assessments of what resources are used by honeybees in AES and understanding the role, if any, which AES play in enhancing pollinator fitness. Discussion We recommend using the methodology in this paper to explore the efficacy of AES before particular flowering species are adopted more widely to give a more complete illustration of the actual efficacy of AES.

Behavior and diversity of floral visitors to Campomanesia adamantium (Myrtaceae)

OpenAIRE

NUCCI, MATEUS; ALVES-JUNIOR, ALTER VIEIRA

2017-01-01

Abstract Considering the important roles of pollinators in ecosystem services, their identification and studies of their behavior would be extremely important to efforts directed towards their preservation and management. With the aim of examining the diversity and behavior of the floral visitors to Campomanesia adamantium (Cambessédes) O. Berg (“guavira”) and how they act in the pollination process, a total of 31 species belonging to the orders Hymenoptera (79.30 %), Coleoptera (11.34 %), Di...

Representações do Corpo Feminino na Menopausa: Estudo Etnográfico em um Hospital-Escola Brasileiro

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Rebeca Buzzo Feltrin

Full Text Available Resumo: O pensamento científico sobre o corpo da mulher sofreu várias modificações no decorrer do tempo. Isto ocorre porque a biologia interage com a história e a cultura para produzir uma experiência única sobre a saúde. No caso específico da menopausa, ela deixou de ser entendida como uma ocorrência natural do processo de envelhecimento da mulher e passou a ser vista como uma doença que requer intervenção médica e farmacêutica. Este artigo analisa como esta nova perspectiva sobre a menopausa aparece no contexto de atendimento do Ambulatório de Menopausa do Centro de Atenção Integral à Saúde da Mulher - CAISM. Buscou-se em particular conhecer as narrativas das mulheres atendidas em função da menopausa e identificar a influência do modelo médico-científico vigente em tais narrativas. A análise se baseia em material coletado no hospital-escola durante o período de setembro de 2009 a outubro de 2010, abrangendo observações no Ambulatório de Menopausa e dos materiais informativos que lá são distribuídos, entrevistas com mulheres e profissionais de saúde, além do acompanhamento do grupo de apoio psicológico oferecido no local. São apresentadas evidências da construção do conhecimento médico-científico sobre a menopausa a partir de um padrão "masculino" de normalidade, que representa o corpo feminino como doente e inferior.

The Biosynthesis of Unusual Floral Volatiles and Blends Involved in Orchid Pollination by Deception: Current Progress and Future Prospects.

Science.gov (United States)

Wong, Darren C J; Pichersky, Eran; Peakall, Rod