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Sample records for birch pollen isoallergens

  1. Quantitative DNA Analyses for Airborne Birch Pollen.

    Directory of Open Access Journals (Sweden)

    Isabell Müller-Germann

    Full Text Available Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR, which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8 and the other for a multi-copy gene (ITS. The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm, the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

  2. Efficacy of recombinant birch pollen vaccine for the treatment of birch-allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Pauli, Gabrielle; Larsen, Tina H; Rak, Sabina

    2008-01-01

    BACKGROUND: Recombinant DNA technology has the potential to produce allergen-specific immunotherapy vaccines with defined composition. OBJECTIVE: To evaluate the effectiveness of a new recombinant birch pollen allergen vaccine in patients with birch pollen allergy. METHODS: A multicenter......, randomized, double-blind, placebo-controlled trial was undertaken to compare the following 3 vaccines in 134 adults with birch pollen allergy: recombinant birch pollen allergen vaccine (rBet v 1a), licensed birch pollen extract, natural purified birch pollen allergen (nBet v 1), and placebo. Patients......-treated group. CONCLUSION: The rBet v 1-based vaccine was safe and effective in treating birch pollen allergy, and induced a highly specific immune response....

  3. Birch pollen allergy: molecular characterization and hypoallergenic products

    NARCIS (Netherlands)

    Schenk, M.F.

    2008-01-01

    Allergic diseases, such as hay fever and food allergy, affect a substantial part of the population in westernized countries. Pollen of the European white birch (Betula pendula) is a considerable cause of hay fever (seasonal allergic rhinitis) in northern and central Europe. The major birch pollen

  4. Oral allergy syndrome to chicory associated with birch pollen allergy

    NARCIS (Netherlands)

    Cadot, P.; Kochuyt, A.-M.; van Ree, R.; Ceuppens, J. L.

    2003-01-01

    BACKGROUND: A few cases of IgE-mediated chicory allergy with oral, cutaneous, and/or respiratory symptoms are reported. We present 4 patients with inhalant birch pollen allergy and oral allergy syndrome to chicory. IgE-binding proteins in chicory and cross-reactivity with birch pollen were studied.

  5. Food allergy to apple and specific immunotherapy with birch pollen

    DEFF Research Database (Denmark)

    Hansen, Kirsten Skamstrup; Khinchi, Marianne Søndergaard; Skov, Per Stahl

    2004-01-01

    Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen-allergic......Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen......-allergic patients were included in a double-blind, double-dummy, and placebo-controlled comparison of sublingual-swallow (SLIT) and subcutaneous (SCIT) administration of a birch pollen extract. Sixty-nine percent of these patients reported allergy to apple. The clinical reactivity to apple was evaluated by open...... oral challenges with fresh apple and a questionnaire. The immunoglobulin E (IgE)-reactivity was assessed by skin prick test (SPT), specific IgE, and leukocyte histamine release (HR). Forty patients were included in the final evaluation of the effect of SIT. The challenges were positive in 9 (SCIT), 6...

  6. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, Lars K; Malling, Hans-Jørgen

    2003-01-01

    a clinical characterization of skin test-positive subjects without symptoms and to ascertain the predictive values of common allergologic tests. METHODS: Asymptomatic adults with positive skin prick test results for birch (n = 15), nonatopic control subjects (n = 25), and birch pollen-allergic patients (n...... = 6) were followed through use of daily diary cards during 3 consecutive birch pollen seasons. At inclusion and at the 3-year follow-up visit, conjunctival and nasal challenges, intradermal late-phase reaction evaluation, and measurement of specific IgE were performed. RESULTS: Asymptomatic sensitized...

  7. Are the birch trees in Southern England a source of Betula pollen for North London?

    Science.gov (United States)

    Skjøth, C. A.; Smith, M.; Brandt, J.; Emberlin, J.

    2009-01-01

    Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts ( n = 60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200-0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

  8. Impact of urbanization of the proteome of birch pollen and its chemotactic activity on human granulocytes

    NARCIS (Netherlands)

    Bryce, M.; Drews, O.; Schenk, M.F.; Menzel, A.; Estrella, N.; Weichenmeier, I.; Smulders, M.J.M.; Buters, J.; Ring, J.; Gorg, A.; Behrendt, H.; Traidl-Hoffmann, C.

    2010-01-01

    Background: Epidemiologic studies reveal a dramatic increase in allergies in the last decades. Air pollution is considered to be one of the factors responsible for this augmentation. The aim of this study was to analyze the impact of urbanization on birch pollen. The birch pollen proteome was

  9. [Oral Allergy Syndrome Following Soy Milk Ingestion in Patients with Birch Pollen Allergy].

    Science.gov (United States)

    Yamamoto, Tetsuo; Asakura, Kohji; Shirasaki, Hideaki; Himi, Tetsuo

    2015-09-01

    Persons allergic to birch pollen often report oral and pharyngeal hypersensitivity to fruit and vegetables, due to immunological cross-reactivity between pollen and foods. This phenomenon is referred to as the oral allergy syndrome (GAS). Such cross-reactive antigen reactions mainly involve Bet v 1, which is the major birch-pollen allergen, and partially involve birch-pollen profilin Bet v 2. Soybean contains Bet v 1-related antigen (Gly m 4), and soy milk often causes the OAS with severe symptoms such as precordial and abdominal burning sensation because soy milk undergoes little denaturation, and this water-soluble liquid is consumed by most people rather quickly. We evaluated the frequency of the oAS after ingestion of soymilk and examined IgE antibodies to various allergens. A total of 167 patients [122 women, 45 men; age range, 4-72 years (mean age, 32 years)], who had experienced GAS episodes and had IgE birch--pollen antibodies, were interviewed. Using the CAP system, we examined IgE antibodies to birch pollen and other allergens. Of 167 patients, 161 were examined for IgE antibodies to Bet v 1, Bet v 2, Gly m 4, and soybean. We evaluated the frequency of the GAS after soy milk ingestion based on reports by GAS patients with birch pollen allergy, and evaluated the positive rates of some of the IgE antibodies. Among the 167 patients with birch-pollen allergy and GAS on ingestion of any of the foods, there were 16 cases (10%) with OAS following soy milk ingestion. In addition, the foods that caused OAS most often were apples (123 cases, 74%), peaches (67%), and cherries (55%), followed by pears (37%) and kiwi (37%). A higher CAP class for birch pollen, Bet v 1, Gly m 4, and soybean was associated with a higher prevalence of OAS to soy milk. Of 15 patients who had GAS on ingestion of soy milk and had birch-pollen allergy, 47% (7cases) were CAP class 1 for soybean and only 7% (case) was CAP class c2, whereas 93% (14cases) were CAP class 1 for Gly m 4, and 87% (3

  10. Daily home measurements of exhaled nitric oxide in asthmatic children during natural birch pollen exposure

    DEFF Research Database (Denmark)

    Vahlkvist, Signe; Sinding, Marianne; Skamstrup, Kirsten

    2006-01-01

    BACKGROUND: Fractional exhaled nitric oxide (FENO) is a sensitive marker of eosinophilic airway inflammation in asthma. Available methods have restricted measurements to the clinic, giving only a snapshot of the disease, which by nature is highly variable. OBJECTIVES: We sought to investigate...... the feasibility, repeatability, accuracy, sensitivity, and biologic plausibility of new handheld equipment for FENO measurements. We studied day-to-day home measurements of FENO during the birch pollen season in children with allergy to birch pollen and a history of mild asthma and rhinoconjunctivitis during...... this season, as well as in nonatopic children. METHODS: Eleven children with mild asthma and allergy to birch pollen, performed daily home measurements of FENO for 6 weeks before and during the birch pollen season by using a handheld FENO monitor (NIOX MINO). Additionally, FENO (chemiluminescence equipment...

  11. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States

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    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G.

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6 %-248 %. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions.

  12. Glutathione-S-transferase: a minor allergen in birch pollen due to limited release from hydrated pollen.

    Directory of Open Access Journals (Sweden)

    Stephan Deifl

    Full Text Available Recently, a protein homologous to glutathione-S-transferases (GST was detected in prominent amounts in birch pollen by proteomic profiling. As members of the GST family are relevant allergens in mites, cockroach and fungi we investigated the allergenic relevance of GST from birch (bGST.bGST was expressed in Escherichia coli, purified and characterized by mass spectrometry. Sera from 217 birch pollen-allergic patients were tested for IgE-reactivity to bGST by ELISA. The mediator-releasing activity of bGST was analysed with IgE-loaded rat basophil leukaemia cells (RBL expressing human FcεRI. BALB/c mice were immunized with bGST or Bet v 1. Antibody and T cell responses to either protein were assessed. IgE-cross-reactivity between bGST with GST from house dust mite, Der p 8, was studied with murine and human sera in ELISA. The release kinetics of bGST and Bet v 1 from birch pollen were assessed in water, simulated lung fluid, 0.9% NaCl and PBS. Eluted proteins were quantified by ELISA and analysed by immunoblotting.Only 13% of 217 birch pollen-allergic patients showed IgE-reactivity to bGST. In RBL assays bGST induced mediator release. Immunization of mice with bGST induced specific IgE and a Th2-dominated cellular immune response comparably to immunization with Bet v 1. bGST did not cross-react with Der p 8. In contrast to Bet v 1, only low amounts of bGST were released from pollen grains upon incubation in water and the different physiological solutions.Although bGST is abundant in birch pollen, immunogenic in mice and able to induce mediator release from effector cells passively loaded with specific IgE, it is a minor allergen for birch pollen-allergic patients. We refer this discrepancy to its limited release from hydrated pollen. Hence, bGST is an example demonstrating that allergenicity depends mainly on rapid elution from airborne particles.

  13. Ventilation scheme, room location and meteorological factors influence indoor birch pollen concentrations

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    Jochner, Susanne; Matiu, Michael; Michaelis, Rico; Menzel, Annette

    2017-04-01

    Allergenic pollen, often in co-occurrence with air pollutants from traffic and industries aggravating its pollen allergenicity, constitutes a major health risk for the urban population during the pollen season. Airborne pollen concentrations are traditionally monitored with fixed pollen traps mounted >10 m above ground on flat roof tops. However, the personal exposure of allergic people mostly depends on their main residences and the local emission patterns. Consequently, the assessment of indoor pollen is essential for human health since people stay most of the day inside buildings. In our study, hourly indoor birch pollen concentrations were measured on eight days in April 2015 with portable pollen traps in five rooms of a university building at Freising, Germany. A traditional pollen trap on the roof of the building provided the background birch pollen concentration which was compared to the respective outdoor values right in front of the rooms. The office and lab rooms were characterised by different aspects and window ventilation schemes. Meteorological data were equally measured at a nearby climate station and directly in front of the windows. The observed flowering phenology of 56 birch trees in the nearer surrounding partly explained daily peaks in airborne pollen concentrations. As expected, outdoor pollen concentrations were larger than indoor concentrations: Mean indoor/outdoor (I/O) ratio was highest (0.75) in a south oriented room with fully opened window and additional mechanical ventilation, followed by two rooms with fully opened windows orientated to the west and north (0.35, 0.12) and lowest in east oriented neighbouring rooms with tilted window (0.19) and with windows only opened for short ventilation (0.07). The latter two rooms even had a birch tree directly flowering in front of the façade. Hourly I/O ratios depended on meteorology and increased with outside temperature and wind speed oriented perpendicular to the window opening. As also

  14. MACC regional multi-model ensemble simulations of birch pollen dispersion in Europe

    NARCIS (Netherlands)

    Sofiev, M.; Berger, U.; Prank, M.; Vira, J.; Arteta, J.; Belmonte, J.; Bergmann, K.C.; Chéroux, F.; Elbern, H.; Friese, E.; Galan, C.; Gehrig, R.; Khvorostyanov, D.; Kranenburg, R.; Kumar, U.; Marécal, V.; Meleux, F.; Menut, L.; Pessi, A.M.; Robertson, L.; Ritenberga, O.; Rodinkova, V.; Saarto, A.; Segers, A.; Severova, E.; Sauliene, I.; Siljamo, P.; Steensen, B.M.; Teinemaa, E.; Thibaudon, M.; Peuch, V.H.

    2015-01-01

    This paper presents the first ensemble modelling experiment in relation to birch pollen in Europe. The seven-model European ensemble of MACC-ENS, tested in trial simulations over the flowering season of 2010, was run through the flowering season of 2013. The simulations have been compared with

  15. Recombinant Mal d 1 facilitates sublingual challenge tests of birch pollen-allergic patients with apple allergy.

    Science.gov (United States)

    Kinaciyan, T; Nagl, B; Faustmann, S; Kopp, S; Wolkersdorfer, M; Bohle, B

    2016-02-01

    It is still unclear whether allergen-specific immunotherapy (AIT) with birch pollen improves birch pollen-related food allergy. One reason for this may be the lack of standardized tests to assess clinical reactions to birch pollen-related foods, for example apple. We tested the applicability of recombinant (r) Mal d 1, the Bet v 1-homolog in apple, for oral challenge tests. Increasing concentrations of rMal d 1 in 0.9% NaCl were sublingually administered to 72 birch pollen-allergic patients with apple allergy. The dose of 1.6 μg induced oral allergy syndromes in 26.4%, 3.2 μg in 15.3%, 6.3 μg in 27.8%, 12.5 μg in 8.3%, 25 μg in 11.1%, and 50 μg in 4.2% of the patients. No severe reactions occurred. None of the patients reacted to 0.9% NaCl alone. Sublingual administration of 50 μg of rMal d 1 induced no reactions in three nonallergic individuals. Our approach allows straight forward, dose-defined sublingual challenge tests in a high number of birch pollen-allergic patients that inter alia can be applied to evaluate the therapeutic efficacy of birch pollen AIT on birch pollen-related food allergy. © 2015 The Authors. Allergy Published by John Wiley & Sons Ltd.

  16. An investigation of the possible immunological relationship between allergen extracts from birch pollen, hazelnut, potato and apple

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Løwenstein, H

    1978-01-01

    In a retrospective study on selected group of patients, the coincidence of birch pollen allergy and a clinically relevant positive prick test reaction to apples and potatoes was confirmed. Immunochemical comparison using the crossed line immunoelectrophoresis technique (CLIE) confirmed partial...... identity between birch pollen and hazelnut. By the same method no partial immunological identity between birch pollen and extracts and fresh peel from apples and potatoes was found. However, both apples and potatoes gave rise to non-immunological affinity precipitates. On this basis it is discussed...

  17. Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen

    Directory of Open Access Journals (Sweden)

    B. G. Pummer

    2012-03-01

    Full Text Available The ice nucleation of bioaerosols (bacteria, pollen, spores, etc. is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behaviour. The average freezing temperatures in laboratory experiments range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromolecules located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our experiments lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compounds.

  18. Numerical simulation of birch pollen dispersion with an operational weather forecast system.

    Science.gov (United States)

    Vogel, Heike; Pauling, Andreas; Vogel, Bernhard

    2008-11-01

    We included a parameterisation of the emissions of pollen grains into the comprehensive model system COSMO-ART. In addition, a detailed density distribution of birch trees within Switzerland was derived. Based on these new developments, we carried out numerical simulations of the dispersion of pollen grains for an episode that occurred in April 2006 over Switzerland and the adjacent regions. Since COSMO-ART is based on the operational forecast model of the German Weather Service, we are presenting a feasibility study of daily pollen forecast based on methods which have been developed during the last two decades for the treatment of anthropogenic aerosol. A comparison of the model results and very detailed pollen counts documents the current possibilities and the shortcomings of the method and gives hints for necessary improvements.

  19. Sustained efficacy and safety of a 300IR daily dose of a sublingual solution of birch pollen allergen extract in adults with allergic rhinoconjunctivitis: results of a double-blind, placebo-controlled study

    OpenAIRE

    Worm, Margitta; Rak, Sabina; de Blay, Frédéric; Malling, Hans-Jorgen; Melac, Michel; Cadic, Véronique; Zeldin, Robert K

    2014-01-01

    Background Allergic rhinoconjunctivitis (ARC) due to birch pollen is a growing health concern in Europe. Here, we report the efficacy and safety of 300IR birch pollen sublingual solution administered discontinuously for 2 consecutive years to patients with birch-associated allergic rhinoconjunctivitis. Methods Birch pollen-allergic adults were randomized in this double blind study to 300IR birch pollen sublingual solution or placebo, daily, starting 4 months before and continuing through the ...

  20. Exposure to high doses of birch pollen during pregnancy, and risk of sensitization and atopic disease in the child.

    Science.gov (United States)

    Kihlström, A; Lilja, G; Pershagen, G; Hedlin, G

    2003-09-01

    The role of maternal allergen exposure during pregnancy in sensitization and development of atopic disease in the child remains controversial. In the spring of 1993, extremely high levels of birch pollen were recorded in Stockholm, Sweden. In 1994, the corresponding pollen levels were low. The aim of this study was to assess the influence of exposure during pregnancy to high/low doses of birch pollen on the risk of sensitization and development of atopic disease in children. In addition, a comparison was made with children exposed to birch pollen in early infancy. Three hundred and eighty-seven children with atopic heredity, born in Stockholm in July-October 1993 or 1994 (mothers exposed during pregnancy), were investigated at age 4.5 years. The children were clinically examined and were skin prick tested (SPT) with inhalant and food allergens. IgE antibodies (RAST) against birch pollen and recombinant birch pollen allergen (rBet v 1) were analysed in serum. A comparison was made with a similar group of children exposed during the same incident, but in the first 3 months of life, in 1993. The children of mothers high-dose exposed during pregnancy in 1993 tended to be more sensitized (SPT > or = 3 mm) to birch pollen than the children with low-dose exposure during the corresponding period in 1994 (7.6 and 4.6%, respectively, OR: 1.7; 95% CI: 0.7-4.1). A similar but weak tendency was seen for positive RAST analyses (> or =0.35 kU/l) against birch pollen and rBet v 1. Children of mothers high-dose exposed during pregnancy were significantly less sensitized to birch pollen than the children high-dose exposed in early infancy (17.9%, OR: 0.4; 95% CI: 0.2-0.7). There was an overall trend towards a slightly increased prevalence of bronchial asthma, allergic rhinoconjunctivitis and atopic dermatitis in the group with mothers high-dose exposed during pregnancy, compared to those with low exposure. Exposure of the mother during pregnancy to high levels of birch pollen

  1. Oxidative Processing Lowers the Ice Nucleation Activity of Birch and Alder Pollen

    Science.gov (United States)

    Gute, Ellen; Abbatt, Jonathan P. D.

    2018-02-01

    Pollen carry water extractable compounds with ice nucleating (IN) activity. This study investigates whether the hydroxyl radical, as the major atmospheric oxidant, can affect the IN activity of silver birch and grey alder subpollen particles under in-cloud conditions for deposition freezing mode conditions at 234 K. It is found that oxidation increases the supersaturation ratio with respect to ice necessary for the onset of ice nucleation and decreases the fraction of particles which initiate ice nucleation. This reduction of IN activity under equivalent oxidation conditions does not occur with a mineral dust sample (Arizona Test Dust). Chemical analysis of fresh and oxidized pollen material indicates a change of molecular structure with a loss of conjugation and an increase in oxidized functional groups, such as carbonyls. This is the first demonstration that in-cloud oxidation may lower the IN abilities of biological particles such as pollen.

  2. NMR resonance assignments of a hypoallergenic isoform of the major birch pollen allergen Bet v 1.

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    Ahammer, Linda; Grutsch, Sarina; Wallner, Michael; Ferreira, Fatima; Tollinger, Martin

    2017-10-01

    In Northern America and Europe a great number of people are suffering from birch pollen allergy and pollen related food allergies. The trigger for these immunological reactions is the 17.5 kDa major birch pollen allergen Bet v 1, which belongs to the family of PR-10 (pathogenesis-related) proteins. In nature, Bet v 1 occurs as a mixture of various isoforms that possess different immunological properties despite their high sequence identities. Bet v 1.0102 (Bet v 1d), which is investigated here, is a hypoallergenic isoform of Bet v 1 and a potential candidate for allergen-specific immunotherapy. We assigned the backbone and side chain 1 H, 13 C and 15 N resonances of this protein and predicted its secondary structure. The NMR-chemical shift data indicate that Bet v 1.0102 is composed of three α-helices and a seven stranded β-sheet, in agreement with the known structure of the hyperallergenic isoform Bet v 1.0101 (Bet v 1a). Our resonance assignments create the foundation for detailed characterization of the dynamic properties of Bet v 1 isoforms by NMR relaxation measurements.

  3. Ara h 8, a Bet v 1-homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy

    NARCIS (Netherlands)

    Mittag, D.; Akkerdaas, J.; Ballmer-Weber, B.K.; Vogel, L.; Wensing, M.; Becker, W.M.; Koppelman, S.J.; Knulst, A.C.; Helbling, A.; Hefle, S.L.; Ree, R. van; Vieths, S.

    2004-01-01

    We recently described patients with soybean allergy mainly mediated by cross-reactivity to birch pollen allergens. A majority of those patients were reported to have peanut allergy. We sought to study the occurrence of peanut allergy in patients allergic to birch pollen and characterized the Bet v

  4. Ara h 8, a Bet v 1-homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy

    NARCIS (Netherlands)

    Mittag, Diana; Akkerdaas, Jaap; Ballmer-Weber, Barbara K.; Vogel, Lothar; Wensing, Marjolein; Becker, Wolf-Meinhard; Koppelman, Stef J.; Knulst, André C.; Helbling, Arthur; Hefle, Susan L.; van Ree, Ronald; Vieths, Stefan

    2004-01-01

    BACKGROUND: We recently described patients with soybean allergy mainly mediated by cross-reactivity to birch pollen allergens. A majority of those patients were reported to have peanut allergy. OBJECTIVE: We sought to study the occurrence of peanut allergy in patients allergic to birch pollen and

  5. The safety and efficacy of subcutaneous birch pollen immunotherapy - a one-year, randomised, double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, L K; Jacobi, H H

    2002-01-01

    BACKGROUND: There is only very limited documentation of the efficacy and safety of high-dose subcutaneous birch pollen immunotherapy (IT) in double-blind, placebo-controlled (DBPC) studies. Birch pollen is a major cause of allergic morbidity in northern Europe and in eastern parts of North America...

  6. Cooking birch pollen-related food: divergent consequences for IgE- and T cell-mediated reactivity in vitro and in vivo

    NARCIS (Netherlands)

    Bohle, Barbara; Zwölfer, Bettina; Heratizadeh, Annice; Jahn-Schmid, Beatrice; Antonia, Yuliya Dall; Alter, Mareike; Keller, Walter; Zuidmeer, Laurian; van Ree, Ronald; Werfel, Thomas; Ebner, Christof

    2006-01-01

    BACKGROUND: The major birch pollen allergen Bet v 1 cross-reacts with homologous food allergens, resulting in IgE-mediated oral allergy syndromes (OASs). To avoid this food, allergy allergologists and guidebooks advise patients to consume birch pollen-related foods after heating. OBJECTIVE: We

  7. The safety and efficacy of subcutaneous birch pollen immunotherapy - a one-year, randomised, double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Bødtger, U; Poulsen, Lars K.; Jacobi, H H

    2002-01-01

    There is only very limited documentation of the efficacy and safety of high-dose subcutaneous birch pollen immunotherapy (IT) in double-blind, placebo-controlled (DBPC) studies. Birch pollen is a major cause of allergic morbidity in northern Europe and in eastern parts of North America....

  8. Climate change and its impact on birch pollen quantities and the start of the pollen season an example from Switzerland for the period 1969-2006.

    Science.gov (United States)

    Frei, Thomas; Gassner, Ewald

    2008-09-01

    As published by the Intergovernmental Panel on Climate Change (IPCC) global warming is a reality and its impact is huge like the increase of extreme weather events, glacier recession, sea level rise and also effects on human health. Among them allergies to airborne pollen might increase or change in pattern due to the invasion of new allergic plants or due to different behavior of plants like earlier flowering. In this study we used the longest Swiss airborne pollen data set to examine the influence of the temperature increase on the time of flowering. In the case of Basel, where pollen data for 38 years are available, it was shown that due to a temperature increase the start of flowering in the case of birch occurred about 15 days earlier. Apart from a shift of the start of the flowering there is also a trend towards higher annual birch pollen quantities and an increase of the highest daily mean pollen concentrations. Due to global warming and because symptoms may appear earlier in the year people suffering from a pollen allergy might face a new unaccustomed situation.

  9. Prevention of birch pollen-related food allergy by mucosal treatment with multi-allergen-chimers in mice.

    Directory of Open Access Journals (Sweden)

    Elisabeth Hoflehner

    Full Text Available Among birch pollen allergic patients up to 70% develop allergic reactions to Bet v 1-homologue food allergens such as Api g 1 (celery or Dau c 1 (carrot, termed as birch pollen-related food allergy. In most cases, specific immunotherapy with birch pollen extracts does not reduce allergic symptoms to the homologue food allergens. We therefore genetically engineered a multi-allergen chimer and tested if mucosal treatment with this construct could represent a novel approach for prevention of birch pollen-related food allergy.BALB/c mice were poly-sensitized with a mixture of Bet v 1, Api g 1 and Dau c 1 followed by a sublingual challenge with carrot, celery and birch pollen extracts. For prevention of allergy sensitization an allergen chimer composed of immunodominant T cell epitopes of Api g 1 and Dau c 1 linked to the whole Bet v 1 allergen, was intranasally applied prior to sensitization.Intranasal pretreatment with the allergen chimer led to significantly decreased antigen-specific IgE-dependent β-hexosaminidase release, but enhanced allergen-specific IgG2a and IgA antibodies. Accordingly, IL-4 levels in spleen cell cultures and IL-5 levels in restimulated spleen and cervical lymph node cell cultures were markedly reduced, while IFN-γ levels were increased. Immunomodulation was associated with increased IL-10, TGF-β and Foxp3 mRNA levels in NALT and Foxp3 in oral mucosal tissues. Treatment with anti-TGF-β, anti-IL10R or anti-CD25 antibodies abrogated the suppression of allergic responses induced by the chimer.Our results indicate that mucosal application of the allergen chimer led to decreased Th2 immune responses against Bet v 1 and its homologue food allergens Api g 1 and Dau c 1 by regulatory and Th1-biased immune responses. These data suggest that mucosal treatment with a multi-allergen vaccine could be a promising treatment strategy to prevent birch pollen-related food allergy.

  10. Prevention of birch pollen-related food allergy by mucosal treatment with multi-allergen-chimers in mice.

    Science.gov (United States)

    Hoflehner, Elisabeth; Hufnagl, Karin; Schabussova, Irma; Jasinska, Joanna; Hoffmann-Sommergruber, Karin; Bohle, Barbara; Maizels, Rick M; Wiedermann, Ursula

    2012-01-01

    Among birch pollen allergic patients up to 70% develop allergic reactions to Bet v 1-homologue food allergens such as Api g 1 (celery) or Dau c 1 (carrot), termed as birch pollen-related food allergy. In most cases, specific immunotherapy with birch pollen extracts does not reduce allergic symptoms to the homologue food allergens. We therefore genetically engineered a multi-allergen chimer and tested if mucosal treatment with this construct could represent a novel approach for prevention of birch pollen-related food allergy. BALB/c mice were poly-sensitized with a mixture of Bet v 1, Api g 1 and Dau c 1 followed by a sublingual challenge with carrot, celery and birch pollen extracts. For prevention of allergy sensitization an allergen chimer composed of immunodominant T cell epitopes of Api g 1 and Dau c 1 linked to the whole Bet v 1 allergen, was intranasally applied prior to sensitization. Intranasal pretreatment with the allergen chimer led to significantly decreased antigen-specific IgE-dependent β-hexosaminidase release, but enhanced allergen-specific IgG2a and IgA antibodies. Accordingly, IL-4 levels in spleen cell cultures and IL-5 levels in restimulated spleen and cervical lymph node cell cultures were markedly reduced, while IFN-γ levels were increased. Immunomodulation was associated with increased IL-10, TGF-β and Foxp3 mRNA levels in NALT and Foxp3 in oral mucosal tissues. Treatment with anti-TGF-β, anti-IL10R or anti-CD25 antibodies abrogated the suppression of allergic responses induced by the chimer. Our results indicate that mucosal application of the allergen chimer led to decreased Th2 immune responses against Bet v 1 and its homologue food allergens Api g 1 and Dau c 1 by regulatory and Th1-biased immune responses. These data suggest that mucosal treatment with a multi-allergen vaccine could be a promising treatment strategy to prevent birch pollen-related food allergy.

  11. Birch pollen influence the severity of atopic eczema – prospective clinical cohort pilot study and ex vivo penetration study

    Directory of Open Access Journals (Sweden)

    Fölster-Holst R

    2015-10-01

    Full Text Available Regina Fölster-Holst,1 Jagoda Galecka,1 Sigo Weißmantel,1 Ute Dickschat,2 Frank Rippke,3 Kerstin Bohnsack,3 Thomas Werfel,4 Katja Wichmann,4 Matthias Buchner,1 Thomas Schwarz,1 Annika Vogt,5 Jürgen Lademann,5 Martina C Meinke5 1Department of Dermatology, Venerology and Allergy, University of Kiel, 2Wörth, 3Beiersdorf AG, Hamburg, 4Department of Dermatology, Venerology and Allergy, Division of Immunodermatology and Allergy Research, Hannover Medical School, Hannover, 5Department of Dermatology, Venerology and Allergology, Charité – Universitätsmedizin Berlin, Berlin, Germany Abstract: There is little clinical evidence for a correlation between the severity of atopic eczema (AE and pollen exposition. To obtain more data, we performed a clinical cohort pilot study about the influence of pollen on AE between sensitized and nonsensitized subjects and an experimental study addressing the cutaneous penetration of pollen into the skin. Fifty-five patients were monitored during birch pollen season. To study the cutaneous penetration, grass pollen allergens were applied on excised skin and the uptake in CD1c-expressing dendritic cells was investigated. The correlation between environmental pollen load and severity of the Scoring Atopic Dermatitis (SCORAD score and pruritus was observed, regardless of the status of sensitization. The sensitized group recovered significantly worse after the birch pollen season. Remarkably higher amounts of pollen allergens taken up by CD1c cells were detected in epidermal cells derived from skin explants with a disturbed epidermal barrier. These findings suggest an exacerbating role of pollen in AE utilizing the epidermal route. Keywords: aeroallergens, atopic eczema, seasonality, skin antigen-presenting cells, skin barrier penetration

  12. The Major Birch Pollen Allergen Bet v 1 Induces Different Responses in Dendritic Cells of Birch Pollen Allergic and Healthy Individuals

    Science.gov (United States)

    Smole, Ursula; Radauer, Christian; Lengger, Nina; Svoboda, Martin; Rigby, Neil; Bublin, Merima; Gaier, Sonja; Hoffmann-Sommergruber, Karin; Jensen-Jarolim, Erika; Mechtcheriakova, Diana; Breiteneder, Heimo

    2015-01-01

    Dendritic cells play a fundamental role in shaping the immune response to allergens. The events that lead to allergic sensitization or tolerance induction during the interaction of the major birch pollen allergen Bet v 1 and dendritic cells are not very well studied. Here, we analyzed the uptake of Bet v 1 and the cross-reactive celery allergen Api g 1 by immature monocyte-derived dendritic cells (iMoDCs) of allergic and normal donors. In addition, we characterized the allergen-triggered intracellular signaling and transcriptional events. Uptake kinetics, competitive binding, and internalization pathways of labeled allergens by iMoDCs were visualized by live-cell imaging. Surface-bound IgE was detected by immunofluorescence microscopy and flow cytometry. Allergen- and IgE-induced gene expression of early growth response genes and Th1 and Th2 related cytokines and chemokines were analyzed by real-time PCR. Phosporylation of signaling kinases was analyzed by Western blot. Internalization of Bet v 1 by iMoDCs of both donor groups, likely by receptor-mediated caveolar endocytosis, followed similar kinetics. Bet v 1 outcompeted Api g 1 in cell surface binding and uptake. MoDCs of allergic and healthy donors displayed surface-bound IgE and showed a pronounced upregulation of Th2 cytokine- and NFκB-dependent genes upon non-specific Fcε receptor cross-linking. In contrast to these IgE-mediated responses, Bet v 1-stimulation increased transcript levels of the Th2 cytokines IL-4 and IL-13 but not of NFκB-related genes in MoDCs of BP allergic donors. Cells of healthy donors were either unresponsive or showed elevated mRNA levels of Th1-promoting chemokines. Moreover, Bet v 1 was able to induce Erk1/2 and p38 MAPK activation in BP allergics but only a slight p38 activation in normal donors. In conclusion, our data indicate that Bet v 1 favors the activation of a Th2 program only in DCs of BP allergic individuals. PMID:25635684

  13. The major birch pollen allergen Bet v 1 induces different responses in dendritic cells of birch pollen allergic and healthy individuals.

    Directory of Open Access Journals (Sweden)

    Ursula Smole

    Full Text Available Dendritic cells play a fundamental role in shaping the immune response to allergens. The events that lead to allergic sensitization or tolerance induction during the interaction of the major birch pollen allergen Bet v 1 and dendritic cells are not very well studied. Here, we analyzed the uptake of Bet v 1 and the cross-reactive celery allergen Api g 1 by immature monocyte-derived dendritic cells (iMoDCs of allergic and normal donors. In addition, we characterized the allergen-triggered intracellular signaling and transcriptional events. Uptake kinetics, competitive binding, and internalization pathways of labeled allergens by iMoDCs were visualized by live-cell imaging. Surface-bound IgE was detected by immunofluorescence microscopy and flow cytometry. Allergen- and IgE-induced gene expression of early growth response genes and Th1 and Th2 related cytokines and chemokines were analyzed by real-time PCR. Phosporylation of signaling kinases was analyzed by Western blot. Internalization of Bet v 1 by iMoDCs of both donor groups, likely by receptor-mediated caveolar endocytosis, followed similar kinetics. Bet v 1 outcompeted Api g 1 in cell surface binding and uptake. MoDCs of allergic and healthy donors displayed surface-bound IgE and showed a pronounced upregulation of Th2 cytokine- and NFκB-dependent genes upon non-specific Fcε receptor cross-linking. In contrast to these IgE-mediated responses, Bet v 1-stimulation increased transcript levels of the Th2 cytokines IL-4 and IL-13 but not of NFκB-related genes in MoDCs of BP allergic donors. Cells of healthy donors were either unresponsive or showed elevated mRNA levels of Th1-promoting chemokines. Moreover, Bet v 1 was able to induce Erk1/2 and p38 MAPK activation in BP allergics but only a slight p38 activation in normal donors. In conclusion, our data indicate that Bet v 1 favors the activation of a Th2 program only in DCs of BP allergic individuals.

  14. Crystallization and preliminary X-ray analysis of birch-pollen allergen Bet v 1 in complex with a murine monoclonal IgG Fab' fragment

    DEFF Research Database (Denmark)

    Spangfort, M D; Mirza, Osman Asghar; Gajhede, M

    1999-01-01

    of the clinical symptoms of allergy. In order to study the structural basis of allergen-antibody interaction, a complex between the major birch-pollen allergen Bet v 1 and a Fab' fragment isolated from the murine monoclonal Bet v 1 antibody BV16 has been crystallized. Complex crystals belong to space group P1...

  15. Sustained efficacy and safety of a 300IR daily dose of a sublingual solution of birch pollen allergen extract in adults with allergic rhinoconjunctivitis: results of a double-blind, placebo-controlled study.

    Science.gov (United States)

    Worm, Margitta; Rak, Sabina; de Blay, Frédéric; Malling, Hans-Jorgen; Melac, Michel; Cadic, Véronique; Zeldin, Robert K

    2014-02-11

    Allergic rhinoconjunctivitis (ARC) due to birch pollen is a growing health concern in Europe. Here, we report the efficacy and safety of 300IR birch pollen sublingual solution administered discontinuously for 2 consecutive years to patients with birch-associated allergic rhinoconjunctivitis. Birch pollen-allergic adults were randomized in this double blind study to 300IR birch pollen sublingual solution or placebo, daily, starting 4 months before and continuing through the pollen season for two pollen seasons. Randomization was stratified according to the presence or absence of oral allergy syndrome (OAS). The primary efficacy endpoint was the Average Adjusted Symptom Score (AAdSS) over the second pollen season and was analyzed by ANCOVA. Secondary efficacy endpoints included the AAdSS over the first pollen period. Safety was evaluated by means of adverse event monitoring. 574 patients (284 in the active group and 290 in the placebo group) were randomized and 496 completed the study. Over the second pollen period, the least square (LS) mean AAdSS was significantly lower in the 300IR group than in the placebo group (LS mean difference -2.04, 95% CI [-2.69, -1.40], (p mouth edema. There were no reports of anaphylaxis. Pre- and co-seasonal treatment with 300IR birch pollen sublingual solution demonstrated sustained clinical efficacy over 2 pollen seasons and was well tolerated in adults with birch pollen-associated allergic rhinoconjunctivitis. Efficacy results were consistent in patients with and without oral allergy syndrome. ClinicalTrials.gov: NCT01731249.

  16. The impact of nitration on the structure and immunogenicity of the major birch pollen allergen Bet v 1.0101.

    Directory of Open Access Journals (Sweden)

    Chloé Ackaert

    Full Text Available Allergy prevalence has increased in industrialized countries. One contributing factor could be pollution, which can cause nitration of allergens exogenously (in the air or endogenously (in inflamed lung tissue. We investigated the impact of nitration on both the structural and immunological behavior of the major birch pollen allergen Bet v 1.0101 to determine whether nitration might be a factor in the increased incidence of allergy. Bet v 1.0101 was nitrated with tetranitromethane. Immune effects were assessed by measuring the proliferation of specific T-cell lines (TCLs upon stimulation with different concentrations of nitrated and unmodified allergen, and by measurement of cytokine release of monocyte-derived dendritic cells (moDCs and primary DCs (primDCs stimulated with nitrated versus unmodified allergen. HPLC-MS, crystallography, gel electrophoresis, amino acid analysis, size exclusion chromatography and molecular dynamics simulation were performed to characterize structural changes after nitration of the allergen. The proliferation of specific TCLs was higher upon stimulation with the nitrated allergen in comparison to the unmodified allergen. An important structural consequence of nitration was oligomerization. Moreover, analysis of the crystal structure of nitrated Bet v 1.0101 showed that amino acid residue Y83, located in the hydrophobic cavity, was nitrated to 100%. Both moDCs and primDCs showed decreased production of TH1-priming cytokines, thus favoring a TH2 response. These results implicate that nitration of Bet v 1.0101 might be a contributing factor to the observed increase in birch pollen allergy, and emphasize the importance of protein modifications in understanding the molecular basis of allergenicity.

  17. Oral administration of Lactobacillus plantarum CJLP133 and CJLP243 alleviates birch pollen-induced allergic rhinitis in mice.

    Science.gov (United States)

    Choi, S-P; Oh, H-N; Choi, C-Y; Ahn, H; Yun, H S; Chung, Y M; Kim, B; Lee, S J; Chun, T

    2018-03-01

    In this study, we evaluated the therapeutic efficacy of selected probiotics in a mouse model of birch pollen (BP)-induced allergic rhinitis. Oral administration of Lactobacillus plantarum CJLP133 and CJLP243 ameliorated the symptoms of BP-induced allergic rhinitis by reducing airway hyperresponsiveness, and both the histological scores and the number of infiltrated cells in the nasal cavities and lungs. Compared with those from vehicle-treated mice, bronchoalveolar lavage fluid and draining lymph node samples from CJLP133 and CJLP243-administrated mice showed diminished numbers of immune cells, increased secretion of a Th1-type cytokine (IFN-γ) and decreased production of Th2-type cytokines (IL-4, IL-5 and IL-13). Consistent with these results, levels of IL-4, IL-5, IL-13, serum IgE and BP-specific serum IgG1 were decreased, whereas secretion of IFN-γ and BP-specific serum IgG2a was augmented upon administration of CJLP133 and CJLP243 in mice. Oral administration of L. plantarum CJLP133 and CJLP243 alleviates symptoms of BP-induced allergic rhinitis in mice by recovering Th1/Th2 balance via enhancement of the Th1-type immune response. Lactobacillus plantarum CJLP133 and CJLP243 have therapeutic effects on BP-induced allergic rhinitis in an animal model. © 2017 The Society for Applied Microbiology.

  18. Detection and analysis of unusual features in the structural model and structure-factor data of a birch pollen allergen.

    Science.gov (United States)

    Rupp, Bernhard

    2012-04-01

    Physically improbable features in the model of the birch pollen structure Bet v 1d (PDB entry 3k78) are faithfully reproduced in electron density generated with the deposited structure factors, but these structure factors themselves exhibit properties that are characteristic of data calculated from a simple model and are inconsistent with the data and error model obtained through experimental measurements. The refinement of the 3k78 model against these structure factors leads to an isomorphous structure different from the deposited model with an implausibly small R value (0.019). The abnormal refinement is compared with normal refinement of an isomorphous variant structure of Bet v 1l (PDB entry 1fm4). A variety of analytical tools, including the application of Diederichs plots, Rσ plots and bulk-solvent analysis are discussed as promising aids in validation. The examination of the Bet v 1d structure also cautions against the practice of indicating poorly defined protein chain residues through zero occupancies. The recommendation to preserve diffraction images is amplified. © 2012 International Union of Crystallography. All rights reserved.

  19. Cloning of the minor allergen Api g 4 profilin from celery (Apium graveolens) and its cross-reactivity with birch pollen profilin Bet v 2.

    Science.gov (United States)

    Scheurer, S; Wangorsch, A; Haustein, D; Vieths, S

    2000-07-01

    Profilin is a panallergen that is recognized by IgE from about 20% of birch pollen- and plant food-allergic patients. A subgroup of celery-allergic patients shows IgE-reactivity with this minor allergen. To investigate the IgE-binding potential and cross-reactivity of celery profilin at the molecular level, this study was aimed at the cloning and immunological characterization of this allergen. Cloning, expression and purification of profilin from celery tuber to characterize its immunological properties and its cross-reactivity with birch pollen profilin. Cloning of celery profilin was performed by polymerase chain reaction using degenerated primers and a 5'RACE method for the identification of the unknown 5'-end of the cDNA. Expression was carried out in Escherichia coli BL21 (DE3) using a modified vector pET-30a. The recombinant profilin was purified by affinity chromatography on poly L-proline coupled to sepharose. Immunological characterization was performed by immunoblotting, EAST and IgE-inhibition experiments. The coding region of the cDNA of celery profilin was identified as a 399-bp open reading frame, coding for a protein of 133 amino acids with a calculated molecular weight of 14.3 kDa. The deduced amino acid sequence of the corresponding protein showed high identity with other plant profilins (71-82%) recently described as allergens. Celery profilin was isolated as highly pure nonfusion protein. The IgE-reactivity of celery profilin was similar to that of natural protein. Seven of 17 celery-allergic patients tested presented specific IgE-antibodies to the recombinant protein tested by immunoblotting. Inhibition experiments showed high cross-reactivity of IgE with both profilins from celery and birch pollen. Moreover, the biological activity of recombinant celery profilin was demonstrated by a histamine release assay. Celery profilin is an important allergenic compound in celery and shows high homology to birch pollen profilin, Bet v 2. According to the

  20. Suitability of temperature sum models to simulate the flowering period of birches on regional scale as basis for realistic predictions of the allergenic potential of atmospheric pollen loads

    Science.gov (United States)

    Biernath, Christian; Hauck, Julia; Klein, Christian; Thieme, Christoph; Heinlein, Florian; Priesack, Eckart

    2014-05-01

    Persons susceptible to allergenic pollen grains need to apply suppressive pharmacy before the occurrence of the first allergy symptoms. Patient targeted medication could be improved if forecasts of the allergenic potential of pollen (biochemical composition of the pollen grain) and the onset, duration, and end of the pollen season are precise on regional scale. In plant tissue the biochemical composition may change within hours due to the resource availability for plant growth and plant internal nutrient re-mobilization. As these processes highly depend on both, the environmental conditions and the development stage of a plant, precise simulations of the onset and duration of the flowering period are crucial to determine the allergenic potential of tissues and pollen. Here, dynamic plant models that consider the dependence of the chemical composition of tissue on the development stage of the plant embedded in process-based ecosystem models seem promising tools; however, today dynamic plant growth is widely ignored in simulations of atmospheric pollen loads. In this study we raise the question whether frequently applied temperature sum models (TSM) could precisely simulate the plant development stages in case of birches on regional scale. These TSM integrate average temperatures above a base temperature below which no further plant development is assumed. In this study, we therefore tested the ability of TSM to simulate the flowering period of birches on more than 100 sites in Bavaria, Germany over a period of three years (2010-2012). Our simulations indicate that the often applied base temperatures between 2.3°C and 3.5°C for the integration of daily or hourly average temperatures, respectively, in Europe are too high to adequately simulate the onset of birch flowering in Bavaria where a base temperature of 1°C seems more convenient. A more regional calibration of the models to sub-regions in Bavaria with comparable climatic conditions could further improve the

  1. Comparative studies on tree pollen allergens. X. Further purification and N-terminal amino acid sequence analyses of the major allergen of birch pollen (Betula verrucosa).

    Science.gov (United States)

    Vik, H; Elsayed, S

    1986-01-01

    The previously isolated major allergen of birch pollen (fraction BV45), Int. Archs Allergy appl. Immun. 68: 70-78 (1982), was further purified by recycling chromatography. The purified preparation was run on a high-performance liquid chromatography (HPLC) TSK-G-2000 gel filtration chromatography column and, finally, on paper high-volt electrophoresis. The protein recovered met the homogeneity criteria required for performing the N-terminal sequence analysis. The allergenic and antigenic reactivities of the HPLC-purified protein, designated BV45B, was examined. A single homogeneous precipitation line in crossed immunoelectrophoresis (CIE) was shown. Specific IgE-inhibition tests and immuno-autoradiographic prints indicated that this allergen could bind reaginic IgE specificially and with good affinity. The homogeneity of BV45B was examined by isoelectric focusing (IEF). Several minor bands of pI differences of less than 0.1 units were visible, demonstrating the existence of some molecular variants of this protein. The N-terminal sequence analysis of the molecule was performed, and the following four amino acids were tentatively shown by sequential cleavage: NH2-Ala-Gly-Ile-Val-. The demonstration of one dominant N-terminal 1-dimethyl-amino-5-naphthalene sulphonyl (DNS)-amino acid by polyamide thin-layer chromatography at each sequence step confirmed that the N-terminal residue of the protein was not blocked; the heterogeneity shown by the IEF system was merely due to the presence of several homologous polymorphic proteins with identical N-terminal amino acid, the adequacy of the purification repertoire used.

  2. [Questionnaire about the intake of and hypersensitivity to fruits, vegetables and nuts including birch pollen related foods].

    Science.gov (United States)

    Yamamoto, Tetsuo; Asakura, Kohji; Shirasaki, Hideaki; Himi, Tetsuo

    2013-07-01

    In Hokkaido and Scandinavia, birch pollen allergic persons are common and they often report oral and pharyngeal hypersensitivity to fruits and vegetables (oral allergy syndrome, OAS), because of immunological cross-reactivity. In Scandinavia, nuts as well as Rosaceae fruits such as apples were the foods most often reported to elicit symptoms. On the other hand, nuts are minor foods causing hypersensitivity in Japan. Even in Japan, regional differences of foods causing hypersensitivity have been reported, which may be related to the regional differences of elementary habit and pollen dispersion. In the present study, we evaluated the intake history of the foods and the frequency of food hypersensitivity in adults from the general population. Three hundreds and thirty nine subjects (20-67 years old) took part in the study. With a questionnaire survey, we asked them about their intake history and hypersensitive symptoms for 33 kinds of fruit, vegetables, and nuts. 30% of subjects had eaten Brazil nuts, 80% had eaten pomegranates, and 81% had eaten hazelnuts. And over 95% of subjects had eaten the other 30 foods. Those who had lived in Hokkaido for more than 20 years had a higher frequency of plum consumption than the others. Those who had lived in Hokkaido for more than 20 years had a lower frequency of loquat, fig and pomegranate consumption than the others. Food hypersensitivity was found in 52 subjects (15.3%). The most common symptom was OAS (46 subjects, 13.6%), and foods most frequently causing OAS were peach (21 subjects, 6.2%), cherry (19 subjects, 5.6%) and apple (17 subjects, 5.0%). 26 subjects (7.7%) reported OAS to Rosaceae fruits. The ratio of having OAS to consuming Rosaceae fruits was 11.0% in the group who had lived in Hokkaido for more than 20 years, which was higher than the group who has lived in Hokkaido for less than 20 years. The intake history of hazelnuts and Brazil nuts was very low, with a correspondingly low frequency of food

  3. Efficacy of sublingual vectorized recombinant Bet v 1a in a mouse model of birch pollen allergic asthma.

    Science.gov (United States)

    Tourdot, Sophie; Airouche, Sabi; Berjont, Nathalie; Moussu, Hélène; Betbeder, Didier; Nony, Emmanuel; Bordas-Le Floch, Véronique; Baron-Bodo, Véronique; Mascarell, Laurent; Moingeon, Philippe

    2013-05-28

    Second generation sublingual allergy vaccines based upon recombinant allergens combined with vector systems are being developed as an alternative to conventional allergen extracts. Herein, we evaluated the efficacy of a recombinant form of the major allergen Bet v 1a (rBet v 1a) formulated as a mucoadhesive particle in a preclinical model of birch pollen (BP) respiratory allergy. BALB/c mice were sensitized to BP extracts by intraperitoneal injections followed by aerosol exposures. Sensitized mice underwent sublingual immunotherapy (SLIT) twice a week for eight weeks with either a BP extract or rBet v 1a formulated in amylopectin-based microparticles (MPA). SLIT efficacy was assessed using whole body plethysmography, lung histology and cell counts in broncho-alveolar lavages (BAL) as read outs. BP and/or rBet v 1a-specific T cell and antibody responses were monitored in lung and serum, respectively. IgA levels were measured in saliva. Mice sensitized to BP exhibit chronic airway hyperresponsiveness (AHR), lung inflammation (documented by compliance and resistance measurements), eosinophil infiltrates in BAL, as well as Bet v 1-specific Th2 biased responses. Both SLIT with soluble rBet v 1a (50μg/dose) and BP extract (equivalent to 50μg rBet v 1 per dose) lead to a significant reduction in AHR, lung eosinophilia and Th2 responses. A sub-optimal dose of 5μg of rBet v 1a displays a similar level of efficacy with a significant decrease of Th2 responses when formulated with MPA microparticles. In addition, allergen vectorization with mucoadhesive particles allows a faster reduction in AHR in sensitized animals. We demonstrate in a murine model of chronic BP respiratory allergy the efficacy of SLIT with vectorized rBet v 1a. Thus, combining recombinant allergens with mucoadhesive vector systems paves the ground for improved second generation sublingual allergy vaccines. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Reactions of airway epithelial cells to birch pollen grains previously exposed to in situ atmospheric Pb concentrations: a preliminary assay of allergenicity.

    Science.gov (United States)

    Bellanger, Anne-Pauline; Bosch-Cano, Floriane; Millon, Laurence; Ruffaldi, Pascale; Franchi, Marielle; Bernard, Nadine

    2012-12-01

    A growing body of evidence suggests that interactions between pollen grains and environmental pollutants, especially air pollutants, could be of critical importance with regard to the increase in allergic responses observed in the past decades. Using birch pollen grains (BPG), a major allergy source in European countries, and lead (Pb), a highly toxic metal trace element (MTE) present in urban areas, the immune response of human epithelial cells exposed to BPG or to Pb-associated BPG was compared. The cellular response after exposure either to BPG, BPG exposed to 30 mg/L of Pb (BPG-30), or BPG exposed to 60 mg/L of Pb (BPG-60) was evaluated after two time lapses (2 and 6 h) by measuring mRNA levels of four mediators, including two inflammatory (interleukin-8 and interleukin-6) and two allergic (interleukin-5 [IL-5] and interleukin-13) cytokines. After 2 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-60 in comparison with exposure to BPG and BPG-30 (N (IL-5) = 1.9, Mann-Whitney test, p = 0.003). After 6 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-30 with N (IL-5) = 1.8 and to BPG-60 with N (IL-5) = 2.3 (Mann-Whitney test, p = 0.0029) in comparison with exposure to BPG. This first attempt to investigate the influence of pollution by MTE on pollen grain showed a dose-time-dependent increase in IL-5 gene expression after exposure to BPG combined to Pb.

  5. Chimeras of Bet v 1 and Api g 1 reveal heterogeneous IgE responses in patients with birch pollen allergy.

    Science.gov (United States)

    Gepp, Barbara; Lengger, Nina; Bublin, Merima; Hemmer, Wolfgang; Breiteneder, Heimo; Radauer, Christian

    2014-07-01

    Characterization of IgE-binding epitopes of allergens and determination of their patient-specific relevance is crucial for the diagnosis and treatment of allergy. We sought to assess the contribution of specific surface areas of the major birch pollen allergen Bet v 1.0101 to binding IgE of individual patients. Four distinct areas of Bet v 1 representing in total 81% of its surface were grafted onto the scaffold of its homolog, Api g 1.0101, to yield the chimeras Api-Bet-1 to Api-Bet-4. The chimeras were expressed in Escherichia coli and purified. IgE binding of 64 sera from Bet v 1-sensitized subjects with birch pollen allergy was determined by using direct ELISA. Specificity was assessed by means of inhibition ELISA. rApi g 1.0101, Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4 bound IgE from 44%, 89%, 80%, 78%, and 48% of the patients, respectively. By comparing the amount of IgE binding to the chimeras and to rApi g 1.0101, 81%, 70%, 75%, and 45% of the patients showed significantly enhanced IgE binding to Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4, respectively. The minority (8%) of the sera revealed enhanced IgE binding exclusively to a single chimera, whereas 31% showed increased IgE binding to all 4 chimeras compared with rApi g 1.0101. The chimeras inhibited up to 70% of IgE binding to rBet v 1.0101, confirming the specific IgE recognition of the grafted regions. The Bet v 1-specific IgE response is polyclonal, and epitopes are spread across the entire Bet v 1 surface. Furthermore, the IgE recognition profile of Bet v 1 is highly patient specific. Copyright © 2014 The Authors. Published by Mosby, Inc. All rights reserved.

  6. Allergic asthmatics show divergent lipid mediator profiles from healthy controls both at baseline and following birch pollen provocation.

    Directory of Open Access Journals (Sweden)

    Susanna L Lundström

    Full Text Available Asthma is a respiratory tract disorder characterized by airway hyper-reactivity and chronic inflammation. Allergic asthma is associated with the production of allergen-specific IgE and expansion of allergen-specific T-cell populations. Progression of allergic inflammation is driven by T-helper type 2 (Th2 mediators and is associated with alterations in the levels of lipid mediators.Responses of the respiratory system to birch allergen provocation in allergic asthmatics were investigated. Eicosanoids and other oxylipins were quantified in the bronchoalveolar lumen to provide a measure of shifts in lipid mediators associated with allergen challenge in allergic asthmatics.Eighty-seven lipid mediators representing the cyclooxygenase (COX, lipoxygenase (LOX and cytochrome P450 (CYP metabolic pathways were screened via LC-MS/MS following off-line extraction of bronchoalveolar lavage fluid (BALF. Multivariate statistics using OPLS were employed to interrogate acquired oxylipin data in combination with immunological markers.Thirty-two oxylipins were quantified, with baseline asthmatics possessing a different oxylipin profile relative to healthy individuals that became more distinct following allergen provocation. The most prominent differences included 15-LOX-derived ω-3 and ω-6 oxylipins. Shared-and-Unique-Structures (SUS-plot modeling showed a correlation (R(2 = 0.7 between OPLS models for baseline asthmatics (R(2Y[cum] = 0.87, Q(2[cum] = 0.51 and allergen-provoked asthmatics (R(2Y[cum] = 0.95, Q(2[cum] = 0.73, with the majority of quantified lipid mediators and cytokines contributing equally to both groups. Unique structures for allergen provocation included leukotrienes (LTB(4 and 6-trans-LTB(4, CYP-derivatives of linoleic acid (epoxides/diols, and IL-10.Differences in asthmatic relative to healthy profiles suggest a role for 15-LOX products of both ω-6 and ω-3 origin in allergic inflammation. Prominent differences at baseline levels indicate

  7. Allergic Asthmatics Show Divergent Lipid Mediator Profiles from Healthy Controls Both at Baseline and following Birch Pollen Provocation

    Science.gov (United States)

    Lundström, Susanna L.; Yang, Jun; Källberg, Henrik J.; Thunberg, Sarah; Gafvelin, Guro; Haeggström, Jesper Z.; Grönneberg, Reidar; Grunewald, Johan; van Hage, Marianne; Hammock, Bruce D.; Eklund, Anders; Wheelock, Åsa M.; Wheelock, Craig E.

    2012-01-01

    Background Asthma is a respiratory tract disorder characterized by airway hyper-reactivity and chronic inflammation. Allergic asthma is associated with the production of allergen-specific IgE and expansion of allergen-specific T-cell populations. Progression of allergic inflammation is driven by T-helper type 2 (Th2) mediators and is associated with alterations in the levels of lipid mediators. Objectives Responses of the respiratory system to birch allergen provocation in allergic asthmatics were investigated. Eicosanoids and other oxylipins were quantified in the bronchoalveolar lumen to provide a measure of shifts in lipid mediators associated with allergen challenge in allergic asthmatics. Methods Eighty-seven lipid mediators representing the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP) metabolic pathways were screened via LC-MS/MS following off-line extraction of bronchoalveolar lavage fluid (BALF). Multivariate statistics using OPLS were employed to interrogate acquired oxylipin data in combination with immunological markers. Results Thirty-two oxylipins were quantified, with baseline asthmatics possessing a different oxylipin profile relative to healthy individuals that became more distinct following allergen provocation. The most prominent differences included 15-LOX-derived ω-3 and ω-6 oxylipins. Shared-and-Unique-Structures (SUS)-plot modeling showed a correlation (R2 = 0.7) between OPLS models for baseline asthmatics (R2Y[cum] = 0.87, Q2[cum] = 0.51) and allergen-provoked asthmatics (R2Y[cum] = 0.95, Q2[cum] = 0.73), with the majority of quantified lipid mediators and cytokines contributing equally to both groups. Unique structures for allergen provocation included leukotrienes (LTB4 and 6-trans-LTB4), CYP-derivatives of linoleic acid (epoxides/diols), and IL-10. Conclusions Differences in asthmatic relative to healthy profiles suggest a role for 15-LOX products of both ω-6 and ω-3 origin in allergic

  8. Cor a 1-reactive T cells and IgE are predominantly cross-reactive to Bet v 1 in patients with birch pollen-associated food allergy to hazelnut.

    Science.gov (United States)

    Hofmann, Claudia; Scheurer, Stephan; Rost, Kathrin; Graulich, Edith; Jamin, Annette; Foetisch, Kay; Saloga, Joachim; Vieths, Stefan; Steinbrink, Kerstin; Adler, Henric S

    2013-05-01

    IgE- and T-cell cross-reactivity contribute to the birch pollen-food syndrome. We performed a comprehensive analysis of T-cell cross-reactivity in primary cell cultures, facilitating the identification of allergen-specific T-cell subpopulations from individual patients. Patients with birch pollen allergy and associated food allergy to hazelnuts, carrots, or both were analyzed for IgE cross-reactivity, T-cell responses, and T-cell cross-reactivity to recombinant Bet v 1.0101 (Bet v 1; birch), Cor a 1.0401 (Cor a 1; hazelnut), and Dau c 1.0104 (Dau c 1; carrot). A novel flow cytometry-based method using a 2-step staining process with fluorescent dyes was established to identify subpopulations of cross-reactive T cells. IgE-binding inhibition tests of individual sera revealed that the vast majority of Cor a 1-reactive IgE was cross-reactive to Bet v 1, whereas Bet v 1-reactive IgE was only partially inhibited by preincubation with Cor a 1. Primary stimulation of T cells with Bet v 1 or Cor a 1 resulted in a significant increase in specific responses to Cor a 1 or Bet v 1 after secondary stimulation, respectively, indicating T-cell cross-reactivity between birch and hazelnut allergens in all patients of the study cohort. Preactivation with Dau c 1 induced less pronounced effects. A novel flow cytometry-based proliferation assay identified a predominant Cor a 1/Bet v 1-cross-reactive T-cell subpopulation within highly Bet v 1/Cor a 1-responsive T cells. Analysis of primary allergen-specific T cells combined with flow cytometry-based proliferation assays facilitates investigation of allergen-specific T-cell subpopulations in subjects and might be helpful to evaluate the effect of birch-specific immunotherapy on pollen-associated food allergies. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  9. Pollen

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past vegetation and climate derived from pollen found in lake and ocean sediments. Parameter keywords describe what was measured in this data set....

  10. IgE and allergen-specific immunotherapy-induced IgG4recognize similar epitopes of Bet v 1, the major allergen of birch pollen.

    Science.gov (United States)

    Groh, N; von Loetzen, C S; Subbarayal, B; Möbs, C; Vogel, L; Hoffmann, A; Fötisch, K; Koutsouridou, A; Randow, S; Völker, E; Seutter von Loetzen, A; Rösch, P; Vieths, S; Pfützner, W; Bohle, B; Schiller, D

    2017-05-01

    Allergen-specific immunotherapy (AIT) with birch pollen generates Bet v 1-specific immunoglobulin (Ig)G 4 which blocks IgE-mediated hypersensitivity mechanisms. Whether IgG 4 specific for Bet v 1a competes with IgE for identical epitopes or whether novel epitope specificities of IgG 4 antibodies are developed is under debate. We sought to analyze the epitope specificities of IgE and IgG 4 antibodies from sera of patients who received AIT. 15 sera of patients (13/15 received AIT) with Bet v 1a-specific IgE and IgG 4 were analyzed. The structural arrangements of recombinant (r)Bet v 1a and rBet v 1a _11x , modified in five potential epitopes, were analyzed by circular dichroism and nuclear magnetic resonance spectroscopy. IgE binding to Bet v 1 was assessed by ELISA and mediator release assays. Competitive binding of monoclonal antibodies specific for Bet v 1a and serum IgE/IgG 4 to rBet v 1a and serum antibody binding to a non-allergenic Bet v 1-type model protein presenting an individual epitope for IgE was analyzed in ELISA and western blot. rBet v 1a _11x had a Bet v 1a - similar secondary and tertiary structure. Monomeric dispersion of rBet v 1a _11x was concentration and buffer-dependent. Up to 1500-fold increase in the EC 50 for IgE-mediated mediator release induced by rBet v 1a _11x was determined. The reduction of IgE and IgG 4 binding to rBet v 1a _11x was comparable in 67% (10/15) of sera. Bet v 1a-specific monoclonal antibodies inhibited binding of serum IgE and IgG 4 to 66.1% and 64.9%, respectively. Serum IgE and IgG 4 bound specifically to an individual epitope presented by our model protein in 33% (5/15) of sera. Patients receiving AIT develop Bet v 1a-specific IgG 4 which competes with IgE for partly identical or largely overlapping epitopes. The similarities of epitopes for IgE and IgG 4 might stimulate the development of epitope-specific diagnostics and therapeutics. © 2016 John Wiley & Sons Ltd.

  11. Vaccination for birch pollen allergy. Induction of affinity-matured or blocking IgG antibodies does not account for the reduced binding of IgE to Bet v 1

    DEFF Research Database (Denmark)

    Svenson, Morten; Jacobi, Henrik H; Bødtger, Uffe

    2003-01-01

    (Betula verrucosa) (Bet v 1), the major allergen in birch pollen, to serum IgG and IgE, separately and in competition. Sera from six birch pollen-allergic patients were obtained before and after 5 years of SAV, and binding was assessed with 125I-Bet v 1. Before SAV, IgG bound more than eight times...... the amount of Bet v 1 compared with IgE, and together they accounted for more than 85% of the serum binding capacity. While SAV induced minimal changes in IgE binding, the IgG binding capacities increased 6-32 times. In contrast, the binding avidities (K(d) 28-40pM) changed less than 20%, pre- and post......-SAV IgG provided similar inhibition of Bet v 1 binding to IgE at equimolar levels, and cross inhibition studies between IgG and IgE showed low inter-individual differences. Following SAV, all sera reduced Bet v 1 binding to CD23(+) cells, correlating with reduced binding of Bet v 1 to IgE (P...

  12. Vaccination for birch pollen allergy. Induction of affinity-matured or blocking IgG antibodies does not account for the reduced binding of IgE to Bet v 1

    DEFF Research Database (Denmark)

    Svenson, Morten; Jacobi, Henrik H; Bødtger, Uffe

    2003-01-01

    (Betula verrucosa) (Bet v 1), the major allergen in birch pollen, to serum IgG and IgE, separately and in competition. Sera from six birch pollen-allergic patients were obtained before and after 5 years of SAV, and binding was assessed with 125I-Bet v 1. Before SAV, IgG bound more than eight times...... the amount of Bet v 1 compared with IgE, and together they accounted for more than 85% of the serum binding capacity. While SAV induced minimal changes in IgE binding, the IgG binding capacities increased 6-32 times. In contrast, the binding avidities (K(d) 28-40pM) changed less than 20%, pre- and post......-SAV IgG provided similar inhibition of Bet v 1 binding to IgE at equimolar levels, and cross inhibition studies between IgG and IgE showed low inter-individual differences. Following SAV, all sera reduced Bet v 1 binding to CD23(+) cells, correlating with reduced binding of Bet v 1 to IgE (P

  13. Ice Nuclei from Birch Trees

    Science.gov (United States)

    Felgitsch, Laura; Seifried, Teresa; Winkler, Philipp; Schmale, David, III; Grothe, Hinrich

    2017-04-01

    While the importance of heterogeneous ice nucleation in the atmosphere is known, we still know very little about the substances triggering these freezing events. Recent findings support the theory that biological ice nuclei (IN) exhibit the ability to play an important role in these processes. Huffman et al. (2013) showed a burst of biological IN over woodlands triggered by rain events. Birch pollen are known to release a high number of efficient IN if incubated in water (Pummer et al. 2012). Therefore birches are of interest in our research on this topic. Plants native to the timberline, such as birch trees, have to cope with very cold climatic conditions, rendering freezing avoidance impossible. These plants trigger freezing in their extracellular spaces to control the freezing process and avoid intracellular freezing, which would have lethal consequences. The plants hereby try to freeze at a temperature well above homogeneous freezing temperatures but still at temperatures low enough to not be effected by brief night frosts. To achieve this, IN are an important tool. The specific objective of our work was to study the potential sources and distribution of IN in birch trees. We collected leaves, fruit, bark, and trunk cores from a series of mature birch trees in Tyrol, Austria at different altitudes and sampling sites. We also collected samples from a birch tree in an urban park in Vienna, Austria. Our data show a sampling site dependence and the distribution of IN throughout the tree. Our data suggest that leaves, bark, and wood of birch can function as a source of IN, which are easily extracted with water. The IN are therefore not restricted to pollen. Hence, the amount of IN, which can be released from birch trees, is tremendous and has been underrated so far. Future work aims to elucidate the nature, contribution, and potential ecological roles of IN from birch trees in different habitats. Huffman, J.A., Prenni, A.J., DeMott, P.J., Pöhlker, C., Mason, R

  14. Vaccination for birch pollen allergy

    DEFF Research Database (Denmark)

    Jakobsen, C G; Bodtger, U; Poulsen, Lars K.

    2005-01-01

    Allergen-specific immunotherapy (SIT) is associated with increased levels of allergen-specific IgG in serum. However, it is not clear to what extent qualitative changes in the allergen binding capacity of IgG may be induced as well.......Allergen-specific immunotherapy (SIT) is associated with increased levels of allergen-specific IgG in serum. However, it is not clear to what extent qualitative changes in the allergen binding capacity of IgG may be induced as well....

  15. Bee Pollen

    Science.gov (United States)

    ... Pollen Extract, Buckwheat Pollen, Extrait de Pollen d’Abeille, Honeybee Pollen, Honey Bee Pollen, Maize Pollen, Pine Pollen, Polen de Abeja, Pollen, Pollen d'Abeille, Pollen d’Abeille de Miel, Pollen de Sarrasin.

  16. Vegetable proteomics: the detection of Ole e 1 isoallergens by peptide matching of MALDI MS/MS spectra of underivatized and dansylated glycopeptides.

    Science.gov (United States)

    Napoli, Anna; Aiello, Donatella; Di Donna, Leonardo; Moschidis, Petros; Sindona, Giovanni

    2008-07-01

    Ole e 1 (NCBI entry gi|14424429) is the major allergen of Oleaceae family. Multiple isoforms and variants are present in varying degrees of distribution. In this report, we present a new approach to the resolution of multiple forms of Ole e 1 from whole antigen extracts, based on a preliminary chemical fractionation procedure followed by MALDI MS and MS/MS measurements. The characterization of Ole e 1 isoallergens was accomplished through the identification of the amino acid sequence including the glycosylation site and the structure of the glycan moieties. The structure feature of the identified Ole e 1.0102 (gi|2465127), main olive allergen [Olea europaea] (gi|13195753), Major pollen allergen Ole e 1 (gi|33329740) and Ole e 1c (gi|1362131) is represented by the point mutation K(106) --> I and by the presence of a glycan moiety. Two other variants Major pollen allergen (Allergen Ole e1) (Ole e I) (gi|14424429) and Ole e 1.0103 protein [Olea europea] (gi|2465129) were identified as nonglycosylated species. These results, partially in disagreement with Swiss-Prot annotation, were validated by matching the MALDI MS/MS spectra of the natural tryptic mixture with those obtained after deglycosylation.

  17. Silvical characteristics of sweet birch (Betula lenta)

    Science.gov (United States)

    William B. Leak

    1958-01-01

    Sweet birch (Betula lenta) is also known as black birch and cherry birch. It is commercially less important than the two principal members of the genus, yellow birch (Betula alleghaniensis) and paper birch (Betula papyrifera).

  18. Animal damage to birch

    Science.gov (United States)

    James S. Jordan; Francis M. Rushmore

    1969-01-01

    A relatively few animal species are responsible for most of the reported damage to the birches. White-tailed deer, yellow-bellied sapsuckers, porcupines, moose, and hares are the major animals involved. We will review reports of damage, discuss the underlying causes, and describe possible methods of control. For example, heavy deer browsing that eliminates birch...

  19. Differential IgE binding to isoallergens from Asian seabass (Lates calcarifer) in children and adults.

    Science.gov (United States)

    Sharp, Michael F; Kamath, Sandip D; Koeberl, Martina; Jerry, Dean R; O'Hehir, Robyn E; Campbell, Dianne E; Lopata, Andreas L

    2014-11-01

    Fish allergy is a common food allergy, with prevalence rates in the general population ranging between 0.2% and 2.3%. In both adults and children fish ranks in the top eight foods known to cause IgE mediated food allergy. Fish allergy is rarely outgrown and individuals with fish allergy may be allergic to some but not all species of fish. Whilst fish allergy occurs around the world, the characterization of allergenic components of individual species of fish has been largely confined to Northern hemisphere and European fish species. To date allergy to commonly consumed fish in the Asian-Pacific region including barramundi (Asian seabass; Lates calcarifer) have been less well investigated. The aim of this study was to identify and characterize allergenic proteins from barramundi in both fish allergic adult and pediatric patients. Serum from 17 fish allergic adults and children from Australia were characterized by immunoblotting and enzyme linked immunosorbent assays (ELISA) against raw and heated barramundi. Molecular analysis of identified allergens included genetic sequencing and generation of recombinant isoallergens. Two novel parvalbumin isoforms of the β-type were identified as the only allergens in barramundi and subsequently designated as Lat c 1.0101 and Lat c 1.0201 by the International Union of Immunological Societies. These two isoallergens do not differ in their ability to bind IgE antibodies, but are differentially expressed in barramundi tissue. This study characterized two novel heat stable parvalbumin allergens from barramundi, with differential IgE binding capacity between adults and pediatric patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Occupational allergy to flowers: immunoblot analysis of allergens in freesia, gerbera and chrysanthemum pollen.

    Science.gov (United States)

    van Toorenenbergen, A W

    2014-10-01

    High exposure to pollen from ornamental flowers can induce an IgE-mediated occupational allergy in florists and horticulture workers. We investigated IgE-binding antigens in chrysanthemum, freesia and gerbera pollen by immunoblot analysis and analysed the cross-reactivity of these pollen with birch, grass and mugwort pollen. In immunoblots with chrysanthemum pollen, major IgE-binding structures were seen with a molecular weight (MW) of approximately 25, 45 and 65 kD. In the immunoblots with freesia pollen, IgE from freesia pollen was directed against two proteins with an MW of approximately 15 kD. Most sera showed IgE binding to an approximately 15 kD band in gerbera pollen; with some sera additional bands were seen in the range of 30-50 kD. IgE binding to chrysanthemum pollen was inhibited by mugwort pollen only, whereas IgE binding to freesia pollen was suppressed by birch, grass and mugwort pollen. The inhibitory activity of birch and grass pollen extract on IgE binding to gerbera pollen extract was serum dependent and ranged from no inhibition to complete inhibition. Occupational exposure to many different flowers induced IgE against all three types of pollen. Exposure in greenhouses to gerbera flowers elicited mainly IgE against gerbera pollen. Mugwort pollen extract inhibited IgE binding to pollen from all three flowers. © 2014 John Wiley & Sons Ltd.

  1. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  2. Insect enemies of birch

    Science.gov (United States)

    James G. Conklin

    1969-01-01

    Native birches are subject to attack by insects at all stages of growth from the germinating seedling to the mature tree. All parts of the tree—roots, stem, branches, foliage, and even the developing seed—may be utilized as feeding sites by insects of one kind or another. An enumeration of the many insects recorded in the literature as feeders on...

  3. T cell epitopes of the major fraction of rye grass Lolium perenne (Lol p I) defined using overlapping peptides in vitro and in vivo. I. Isoallergen clone1A.

    Science.gov (United States)

    Bungy Poor Fard, G A; Latchman, Y; Rodda, S; Geysen, M; Roitt, I; Brostoff, J

    1993-10-01

    One hundred and fifteen overlapping synthetic peptides spanning the entire sequence of the iso-allergen clone1A of Lol p I from rye grass Lolium perenne were synthesized by the multi-pin technique. The peptides were overlapping 12mers, offset by two residues and overlapping by 10 residues. Sets of six adjacent overlapping peptides (except pool-1, 15, 20) were pooled and were used in vitro and in vivo to map the T cell epitopes on Lol p I. Six atopics who were skin test and RAST positive to rye grass showed T cell responses to L. perenne extract (LPE) and its major fraction (Lol p I). Five out of six showed T cell responses in vitro to peptide pool-17, while five non-atopics did not respond to any of the peptide pools. By testing the individual peptides of pool-17, we have located the T cell epitope on Lol p I. Interestingly, when we tested pool-17 and its single peptides in vivo by intradermal skin testing we found in one patient a typical DTH after 24-48 h to pool-17 and its peptides (peptides 3 and 4) which exactly matched the in vitro responses. By defining the T cell epitopes in this way a greater understanding of the allergic response to pollen will be obtained, and a more effective and less dangerous vaccine may be possible for treating patients with hay fever.

  4. Are there changes in Germany regarding the start of the pollen season, the season length and the pollen concentration of the most important allergenic pollens?

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Uwe [Centre for Human Biometeorological Research, Freiburg (Germany). German Meteorological Service; Glod, Tom [Univ. of Trier (Germany). FB Physical Geography

    2011-10-15

    For the regions Northwest, Northeast and Southern Germany we examined the main allergic pollen (Hazel, Alder, Birch, grasses and Mugwort) for trends on the basis of the pollen counts of the Pollen Information Service (PID) reference-stations. From these stations information about changes on the start of the pollen season, the season length and the total amount as well as the peak-concentration of pollen during the last years (1988-2009 for Northwest and Southern Germany and 1994-2009 for Northeast Germany) are examined. Possible trends are analysed by means of the Mann-Kendall test for their significance. The results demonstrate that the changes, regarding the start of the pollen season and the total pollen amount, are strongest in Southern and Northeast Germany. Data show for all regions that tree pollen becomes the significant allergen. (orig.)

  5. Pollen Season Trends (1973-2013 in Stockholm Area, Sweden.

    Directory of Open Access Journals (Sweden)

    Tomas Lind

    Full Text Available In the present study, the phenological and quantitative changes in the pollen seasons between 1973 and 2013 in the Stockholm region of Sweden were studied for nine types of pollen (hazel, alder, elm, birch, oak, grass, mugwort, willow and pine. Linear regression models were used to estimate the long term trends in duration, start- and end-dates, peak-values and the yearly accumulated pollen sums of the pollen seasons. The pollen seasons of several arboreal plant species (e.g. birch, oak and pine were found to start significantly earlier today compared to 41 years earlier, and have an earlier peak-date, while the season of other species seemed largely unaffected. However, the long term trends in the end-dates of pollen seasons differed between arboreal and herbaceous species. For herbaceous species (grass and mugwort, a significant change towards later end-dates was observed and the duration of season was found to have increased. A significant trend towards an earlier end-date was found in the majority of the arboreal plant species (i.e. elm, oak, pine and birch, but the length of the season seemed unaffected. A trend towards an increase in yearly concentrations of pollen was observed for several species; however the reasons for this phenomenon cannot be explained unambiguously by the present study design. The trend of increasing yearly mean air temperatures in the Stockholm area may be the reason to changed phenological patterns of pollen seasons.

  6. Lactobacillus strains differentially modulate cytokine production by hPBMC from pollen allergic patients

    NARCIS (Netherlands)

    Vissers, Y.M.; Snel, J.; Zuurendonk, P.F.; Kleerebezem, M.; Wichers, H.J.; Savelkoul, H.F.J.

    2011-01-01

    The objective of this study was to assess the potential immunomodulatory effect of six Lactobacillus strains on human peripheral blood mononuclear cells (hPBMC) isolated from allergic patients. hPBMC from patients allergic to birch pollen or grass pollen were cultured in vitro in the presence or

  7. Next generation immunotherapy for tree pollen allergies.

    Science.gov (United States)

    Su, Yan; Romeu-Bonilla, Eliezer; Heiland, Teri

    2017-10-03

    Tree pollen induced allergies are one of the major medical and public health burdens in the industrialized world. Allergen-Specific Immunotherapy (AIT) through subcutaneous injection or sublingual delivery is the only approved therapy with curative potential to pollen induced allergies. AIT often is associated with severe side effects and requires long-term treatment. Safer, more effective and convenient allergen specific immunotherapies remain an unmet need. In this review article, we discuss the current progress in applying protein and peptide-based approaches and DNA vaccines to the clinical challenges posed by tree pollen allergies through the lens of preclinical animal models and clinical trials, with an emphasis on the birch and Japanese red cedar pollen induced allergies.

  8. Birch regeneration: a stochastic model

    Science.gov (United States)

    William B. Leak

    1968-01-01

    The regeneration of a clearcutting with paper or yellow birch is expressed as an elementary stochastic (probabalistic) model that is computationally similar to an absorbing Markov chain. In the general case, the model contains 29 states beginning with the development of a flower (ament) and terminating with the abortion of a flower or seed, or the development of an...

  9. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bodtger, Uffe; Poulsen, Lars K.; Malling, Hans-Jørgen

    2003-01-01

    The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults.......The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults....

  10. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bodtger, Uffe; Poulsen, Lars K.; Malling, Hans-Jørgen

    2003-01-01

    The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults....

  11. Pollen production in selected species of anemophilous plants

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska

    2012-12-01

    Full Text Available In the study, structural features of flowers of the following allergenic plant species were analysed: Betula verrucosa, Secale cereale, Rumex acetosella, Plantago major and Artemisia vulgaris. Pollen production was established by calculating the number of pollen grains produced by the stamen, flower and inflorescence. The dates of occurrence and pollen grains concentration in the air of Lublin were determined. A positive correlation was found between the length of anthers and the number of pollen grains produced. The largest number of pollen grains per anther is produced by Secale cereale (22 360, whereas the smallest one by Plantago major (5 870. The other species produced intermediate numbers of pollen grains in the anther: Betula verrucosa - 11 160, Rumex acetosella - 10 850, Artemisia vulgaris - 9 580. The birch pollen season in Lublin lasts about a month, and pollen of this taxon reaches the highest airborne concentrations among the studied taxa. Low values of pollen concentrations are characteristic for rye and plantain, whereas slightly higher values are recorded for sorrel pollen. Mugwort pollen reaches high concentrations which are noted at the beginning of August.

  12. Birch's Law for fluid metals

    International Nuclear Information System (INIS)

    Shaner, J.W.; Hixson, R.S.; Winkler, M.A.; Boness, D.A.; Brown, J.M.

    1987-01-01

    By comparing acoustic velocities in fluid metals over a very wide range of densities we have established Birch's Law as an approximate representation over the entire liquid range. For a given liquid metal the acoustic velocity is close to linear in density, with a slope determined by the atomic weight. The measurements include isobaric expansion to less than half normal density, ultrasonics on molten metals at 1 atmosphere, and shock melted metals to greater than twice normal density

  13. Can we improve pollen season definitions by using the symptom load index in addition to pollen counts?

    International Nuclear Information System (INIS)

    Bastl, Katharina; Kmenta, Maximilian; Geller-Bernstein, Carmi; Berger, Uwe; Jäger, Siegfried

    2015-01-01

    Airborne pollen measurements are the foundation of aerobiological research and provide essential raw data for various disciplines. Pollen itself should be considered a relevant factor in air quality. Symptom data shed light on the relationship of pollen allergy and pollination. The aim of this study is to assess the spatial variation of local, regional and national symptom datasets. Ten pollen season definitions are used to calculate the symptom load index for the birch and grass pollen seasons (2013–2014) in Austria. (1) Local, (2) regional and (3) national symptom datasets are used to examine spatial variations and a consistent pattern was found. In conclusion, national datasets are suitable for first insights where no sufficient local or regional dataset is available and season definitions based on percentages provide a practical solution, as they can be applied in regions with different pollen loads and produce more constant results. - Highlights: • The definition of the pollen season has an impact on the calculated symptom load. • Pollen season definitions based on percentages of total pollen are a practical solution. • The symptom load index is a robust tool to assess the allergy burden in a population. • Local, regional and national burdens of pollen allergy sufferers are comparable. - The symptom load index is a robust tool to assess the allergy burden in a population. Local, regional and national burdens of pollen allergy sufferers are comparable

  14. Mimotopes for Api g 5, a Relevant Cross-reactive Allergen, in the Celery-Mugwort-Birch-Spice Syndrome.

    Science.gov (United States)

    Lukschal, Anna; Wallmann, Julia; Bublin, Merima; Hofstetter, Gerlinde; Mothes-Luksch, Nadine; Breiteneder, Heimo; Pali-Schöll, Isabella; Jensen-Jarolim, Erika

    2016-03-01

    In the celery-mugwort-birch-spice syndrome, a significant proportion of IgE is directed against high molecular weight (HMW) glycoproteins, including the celery allergen Api g 5. BIP3, a monoclonal antibody originally raised against birch pollen, recognizes HMW allergens in birch and mugwort pollens, celery, and Apiaceae spices. Our aim was to generate mimotopes using BIP3 for immunization against the HMW allergens relevant in the celery-mugwort-birch-spice cross reactivity syndrome. Mimotopes were selected from a random-peptide display library by BIP3 and applied in IgE inhibition assays. The 3 phage clones with the highest inhibitory capacity were chosen for immunization of BALB/c mice. Mouse immune sera were tested for IgG binding to blotted birch pollen extract and used for inhibiting patients' IgE binding. Furthermore, sera were tested for binding to Api g 5, to horseradish peroxidase (HRP) as a second glycoprotein, or to non-glycosylated control allergen Phl p 5 in ELISA, and the specific Api g 5-specific IgG titers were determined. Three rounds of biopanning resulted in phage clones exhibiting 7 different sequences including 1 dominant, 1-6-cyclo-CHKLRCDKAIA. Three phage clones had the capacity to inhibit human IgE binding and induced IgG to the HMW antigen when used for immunizing BALB/c mice. The induced BIP3-mimotope IgG reached titers of 1:500 specifically to Api g 5, but hardly reacted to glycoprotein HRP, revealing a minor role of carbohydrates in their epitope. The mimotopes characterized in this study mimic the epitope of BIP3 relevant for Api g 5, one of the cross-reactive HMW allergens relevant in the celery-mugwort-birch-spice syndrome. BIP3 mimotopes may be used in the future for hyposensitization in this clinical syndrome by virtue of good and specific immunogenicity.

  15. Immunoproteomic characterization of Ambrosia artemisiifolia pollen allergens in canine atopic dermatitis.

    Science.gov (United States)

    Ognjenovic, Jana; Milcic-Matic, Natalija; Smiljanic, Katarina; Vuckovic, Olga; Burazer, Lidija; Popovic, Nikola; Stanic-Vucinic, Dragana; Velickovic, Tanja Cirkovic

    2013-09-01

    Canine atopic dermatitis (CAD) is an immune system disorder that affects 10-15% of the canine population. Short ragweed (Ambrosia artemisiifolia) pollen represents one of the major seasonal sources of allergenic pollen proteins in Europe, particularly in the Pannonian valley of the Balkan region. In Serbia, about 66% of atopic dogs showed a positive intradermal skin test with its pollen extract, which is second to house dust mites. Therefore, characterization of Ambrosia artemisiifolia pollen components, in terms of defining major and minor allergens that induce clinically manifested allergic reaction in dogs, is important for valid diagnosis and efficient therapy. This study has, for the first time, characterized and identified major Ambrosia artemisiifolia allergens in CAD, using an immunoproteomic approach. To assess the prevalence of specific IgE in electrophoretically separated ragweed pollen proteins, individual reactivity of sera from dogs with CAD was analyzed and compared to the reactivity of sera from healthy dogs in the non-reducing conditions, which were found optimal for specific canine IgE detection. A specific IgE band (38 kDa) was recognized as the most dominant allergen in CAD, occurring in 81% of positive dog's sera. 2-D immunoblotting followed by a mass spectrometry peptide fingerprint analyses with pooled canine and human atopic sera, revealed that 38 kDa major Ambrosia atremisiifolia allergens in CAD were all five isoallergens of the Amb a 1 group (antigen E), including the previously named Amb a 2 (antigen K). In contrast to canine sera, human atopic sera also recognized lower mass allergens such as the β fragment of Amb a 1 and profilins (Amb a 8 variants). The most prominent ragweed proteins in CAD, represent, as in humans, variants of all five isoallergens of the Amb a 1 group (pectate lyase): Amb a 1.0101 and its natural variant E1XUL2, Amb a 1.0202, 1.0304, 1.0402 and the natural variant of Amb a 1.0501, E1XUM0, as well as the

  16. Management of birch for aesthetics and recreation

    Science.gov (United States)

    John H. Noyes

    1969-01-01

    When paper birch and yellow birch are managed for aesthetic and recreation purposes, timber values become secondary, although in some instances compatibility exists among the several objectives. At times, timber and wood-products production is excluded entirely in the interests of aesthetics and recreation. In keying forest-management practices to the appearance...

  17. [The effect of climate change on pollen allergy in the Netherlands].

    Science.gov (United States)

    de Weger, Letty A; Hiemstra, Pieter S

    2009-01-01

    Climate change can exert a range of effects on pollen, which might have consequences for pollen-allergic patients. New allergenic pollen types might appear in the Netherlands, like common ragweed and olive, which result in allergy patients developing allergies that scarcely occur in the Netherlands at present. Trees, such as birches and planes, might produce larger quantities of pollen, which could result in more severe symptoms. The pollen season might become longer thereby extending the period in which patients suffer from allergy symptoms. This extension of the pollen season could be due to a prolonged flowering period of certain species, e.g. grasses, or the appearance of new species that flower in late summer, e.g. common ragweed. Climate change could cause an increase in heavy thunderstorms on summer days in the grass pollen season, which are known to increase the chance of asthma exacerbations.

  18. Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

    Science.gov (United States)

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-01-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  19. Olive (Olea europea) and privet (Ligustrum vulgare) pollen allergens. Identification and cross-reactivity with grass pollen proteins.

    Science.gov (United States)

    Baldo, B A; Panzani, R C; Bass, D; Zerboni, R

    1992-10-01

    Protein blotting studies showed that three olive pollen components with mol. wts approximately 18-19, 20 and 40 kD can be considered to be major allergens. For privet pollen, the highest recognition frequencies were for allergens of mol. wts approximately 20, approximately 19, approximately 40 and approximately 70 kD. When results with the 62 subjects examined were separated into groups corresponding to their geographical locations, viz. Italy, France and Australia, subjects sensitized to olive, but not other pollens (some Italian subjects), were found to show higher frequencies of recognition of major olive allergens than subjects sensitized to olive pollen via cross-reacting allergens from unrelated pollen sources (the Australian and French subjects). Blotting, adsorption and elution and inhibition studies clearly demonstrated allergenic cross-reactivity (that is, antigenic cross-reactivity detected by IgE antibodies) between olive, privet, ryegrass (Lolium perenne) and couch grass (Bermuda grass: Cynodon dactylon) pollen components. As with our previous findings with birch pollen, we conclude that the presence of pollen-reactive IgE antibodies may not necessarily be a true reflection of the sensitizing pollen species.

  20. Management of birch for wildlife habitat

    Science.gov (United States)

    Samuel P. Shaw

    1969-01-01

    The list of wildlife species known to prefer paper birch and yellow birch as food ls a long one. To mention a few: beavers and porcupines chew on the bark and wood; sapsuckers feed on the sap; other songbirds—notably the redpoll, pine siskin, and chikadee—relish the seeds; ruffed grouse eat the catkins, buds, and seeds (in northern Maine and Canada...

  1. Paper birch decline in the Niobrara River Valley, Nebraska: Weather, microclimate, and birch stand conditions

    Science.gov (United States)

    Stroh, Esther D.; Miller, Joel P.

    2009-01-01

    The Niobrara River Valley in north-central Nebraska supports scattered stands of paper birch (Betula papyrifera Marsh), a species more typical of boreal forests. These birch stands are considered to be relictual populations that have persisted since the end of the Wisconsin glaciation, when regional flora was more boreal in nature (Wright 1970, Kaul and others, 1988). Dieback of canopy-sized birch has been observed throughout the Niobrara Valley in recent years, although no onset dates are documented. The current dieback event probably started around or after the early 1980’s. The study objectives were to understand microclimatic conditions in birch stands relative to nearby weather stations and historic weather conditions, and to assess current health conditions of individual birch trees. Temperature was measured every half-hour from June 2005 through October 2007 in 12 birch stands and individual birch tree health was measured as expressed by percent living canopy in these and 13 additional stands in spring 2006 and 2007. Birch site microclimate was compared to data from a National Weather Service station in Valentine, Nebraska, and to an automated weather station at The Nature Conservancy Niobrara Valley Preserve 24 kilometers north of Johnstown, Nebraska. Historic weather data from the Valentine station and another National Weather Service Station at Ainsworth, Nebraska, were used to reconstruct minimum and maximum temperature at The Nature Conservancy and one microclimate monitoring station using Kalman filtering and smoothing algorithms. Birch stand microclimate differed from local weather stations as well as among stands. Birch health was associated with annual minimum temperature regimes; those stands whose annual daily minimum temperature regimes were most like The Nature Conservancy station contained smaller proportions of living trees. Frequency of freeze/thaw conditions capable of inducing rootlet injury and subsequent crown dieback significantly have

  2. Aeroallergen analyses and their clinical relevance. II. Sampling by high-volume airsampler with immunochemical quantification versus Burkard pollen trap sampling with morphologic quantification

    DEFF Research Database (Denmark)

    Johnsen, C R; Weeke, E R; Nielsen, J

    1992-01-01

    operated 24 h a day. They were placed less than 5 m apart, and estimation of the pollen amount was made on a day-to-day basis during the pollen seasons, and on a weekly basis outside the seasons. The occurrence of the 3 clinically most important allergenic types of pollen, birch, grass, and mugwort......, was analysed, and close correlations between the 2 sampling techniques were found (rs 0.5-0.8, p 1 SQ-U/m3, respectively...

  3. High exposure to endotoxin in farming is associated with less new-onset pollen sensitisation

    DEFF Research Database (Denmark)

    Elholm, Grethe; Schlünssen, Vivi; Doekes, Gert

    2018-01-01

    of 1113 young Danish farmers and rural controls, with a mean age of 19 years at baseline. Sensitisation to birch pollen, grass pollen, cat dander and house dust mite was measured by specific IgE levels in serum samples from baseline and at 15 years' follow-up. Changes in sensitisation were analysed...... was not associated with significant changes in cat dander and house dust mite sensitisation. CONCLUSIONS: High exposure to endotoxin during young adulthood appears to protect against new onset of pollen sensitisation, independent of childhood farm exposure....

  4. Pollen analyses for pollination research, unacetolyzed pollen

    Directory of Open Access Journals (Sweden)

    Gretchen D. Jones

    2012-10-01

    Full Text Available Pollinators feed on the pollen, nectar, and other plant exudates that are associated with flowers. As a result of this feeding activity, pollen becomes attached to them. Analysis of this pollen can reveal what they eat, their dispersal patterns in and around cropping systems, and their role in pollination. However, finding pollen on and or in a pollinator depends on the technique used to recover pollen. Two very easy techniques are described in detail that have been used to recover pollen from a variety of pollinators including beneficial and harmful insects, spiders, bats, and other pollinators. These techniques can be used to recover pollen from internal tissues (gut, alimentary canal, crop, etc., external tissues (proboscis, legs, eyes, etc., or both. By using the proper technique, better pollen recovery can be made and thus better data can be obtained about the pollinators, the foods they eat, the plants they pollinate, their migration routes and source zones.

  5. Posttranslational modification of Birch and Ragweed allergen proteins by common gas phase pollutants, NO2 and O3

    Science.gov (United States)

    Mahmood, M. A.; Pope, F.; Bloss, W.

    2015-12-01

    The global incidence of hay fever has been rising for decades, however, the underlying reasons behind this rise remain unclear. It is hypothesized that exposure of pollen to common gas phase pollutants, such as nitrogen dioxide (NO2) and ozone (O3), increases the allergenicity of the pollen and thus increases hay fever incidence. Since atmospheric pollutants tend to have greater concentrations within urban areas (in particular NO2) the hypothesis suggests that greater allergenicity should occur in urban areas. Indeed, several studies do suggest higher hay fever incidence within urban areas compared to rural areas. Previous published work suggests a link between increased allergies with changes in the chemical composition of the pollen protein via posttranslational modification of the protein. This study investigates the posttranslational modification of two highly allergenic pollen species (Birch and Ragweed) that are common in Europe. Within the laboratory, we expose pollen grains to atmospherically relevant exposures of gas phase NO2, O3 and other common gas phase oxidants under a range of environmentally relevant conditions. The effects of the environmentally relevant exposures on the biochemistry of the pollen grains were probed using a proteomic approach (liquid chromatography coupled ultra-high resolution spectrometer). Our findings indicate the interaction between gas phase pollutants and pollen cause protein specific modifications; in particular, nitration occurs upon tyrosine residues and nitrosylation on cysteine residues. Possibly, these modifications may affect the immune response of the pollen protein, which may suggest a possible reason for increased allergies in reaction to such biologically altered protein. The laboratory-derived results will be supported with a time series analysis of asthma incidence rates for the London area, which take into account the pollen count, and pollutant concentrations. The implications of the results will be discussed

  6. Rapid Crustal Uplift at Birch Bay, Washington

    Science.gov (United States)

    Sherrod, B. L.; Kelsey, H. M.; Blakely, R. J.

    2010-12-01

    Geomorphology and coastal marsh stratigraphy suggest late Holocene uplift of the shoreline at Birch Bay, located northwest of Bellingham, Washington, during an earthquake on a shallow fault. LiDAR images show a raised, late Holocene shoreline along Birch Bay, with ~1 m of elevation difference between the modern shoreline and the inferred paleoshoreline. Commercial seismic reflection images reveal an anticline in Tertiary and possibly Quaternary deposits underlying Birch Bay. NW-trending magnetic anomalies are likely associated with the Birch Bay anticline and other nearby structures. Taken together, the geophysical data and lidar images suggest uplift of young deposits along a NW-trending blind reverse fault. Stratigraphy from Terrell Creek marsh, located just south of Birch Bay, shows freshwater peat buried by lower intertidal muds, indicating local submergence ~1300 yr BP. Stratigraphy of a 70-cm sediment core from Birch Bay marsh, sitting astride the anticline imaged with seismic reflection data, shows mud buried by detrital peat. One radiocarbon age from the core places the abrupt change from mud to peat prior to 1520-1700 yr BP. We divide fossil diatom assemblages straddling the mud-peat contact at Birch Bay into three zones. The oldest zone consists primarily of intertidal and marine diatoms, dominated by Paralia sulcata, Scoleoneis tumida, Grammataphora oceanica, and Gyrosigma balticum. An intermediate zone, beginning at the sharp contact between mud and overlying peat, consists of a mixture of brackish marsh and freshwater species, dominated by Diploneis interrupta, with lesser amounts of Aulacoseira sp., Pinnularia viridis, Eunotia pectinalis, and Paralia sulcata. A third and youngest zone lies in the upper half of the peat and is dominated by poorly preserved freshwater diatoms, mostly Aulacoseira cf. crassapuntata, Pinnularia viridis, P. maior, Eunotia pectinalis, and E. praerupta. Paleoecological inferences, based on distributions of modern diatoms

  7. Investigation of heterogeneous ice nucleation in pollen suspensions and washing water

    Science.gov (United States)

    Dreischmeier, Katharina; Budke, Carsten; Koop, Thomas

    2014-05-01

    Biological particles such as pollen often show ice nucleation activity at temperatures higher than -20 °C. Immersion freezing experiments of pollen washing water demonstrate comparable ice nucleation behaviour as water containing the whole pollen bodies (Pummer et al., 2012). It was suggested that polysaccharide molecules leached from the grains are responsible for the ice nucleation. Here, heterogeneous ice nucleation in birch pollen suspensions and their washing water was investigated by two different experimental methods. The optical freezing array BINARY (Bielefeld Ice Nucleation ARraY) allows the direct observation of freezing of microliter-sized droplets. The IN spectra obtained from such experiments with birch pollen suspensions over a large concentration range indicate several different ice nucleation active species, two of which are present also in the washing water. The latter was probed also in differential scanning calorimeter (DSC) experiments of emulsified sub-picoliter droplets. Due to the small droplet size in the emulsion samples and at small concentration of IN in the washing water, such DSC experiments can exhibit the ice nucleation behaviour of a single nucleus. The two heterogeneous freezing signals observed in the DSC thermograms can be assigned to two different kinds of ice nuclei, confirming the observation from the BINARY measurements, and also previous studies on Swedish birch pollen washing water (Augustin et al., 2012). The authors gratefully acknowledge funding by the German Research Foundation (DFG) through the project BIOCLOUDS (KO 2944/1-1) and through the research unit INUIT (FOR 1525) under KO 2944/2-1. We particularly thank our INUIT partners for fruitful collaboration and sharing of ideas and IN samples. S. Augustin, H. Wex, D. Niedermeier, B. Pummer, H. Grothe, S. Hartmann, L. Tomsche, T. Clauss, J. Voigtländer, K. Ignatius, and F. Stratmann, Immersion freezing of birch pollen washing water, Atmos. Chem. Phys., 13, 10989

  8. Pyrrolizidine alkaloids in pollen and pollen products.

    Science.gov (United States)

    Kempf, Michael; Heil, Sandra; Hasslauer, Iris; Schmidt, Lukas; von der Ohe, Katharina; Theuring, Claudine; Reinhard, Annika; Schreier, Peter; Beuerle, Till

    2010-02-01

    Recently, 1,2-dehydropyrrolizidine alkaloid (PA) ester alkaloids, found predominantly as their N-oxides (PANOs, pyrrolizidine N-oxides), have been reported in both honey and in pollen obtained directly from PA plants and pollen loads collected by bees, raising the possibility of health risks for consumers of these products. We confirm these findings in regard to floral pollen, using pollen collected directly from flowers of the known PA plants Senecio jacobaea, S. vernalis, Echium vulgare and pollinia of Phalaenopsis hybrids, and we extend analyses of 1,2-unsaturated PAs and 1,2-unsaturated PANOs to include bee-pollen products currently being sold in supermarkets and on the Internet as food supplements. PA content of floral pollen ranged from 0.5 to 5 mg/g. The highest values were observed in pollen obtained from Senecio species. Up to 95% of the PAs are found as PANOs. Detailed studies with S. vernalis revealed unique PA patterns in pollen and flowers. While seneciphylline was the most prominent PA in S. vernalis pollen, the flowers were dominated by senecionine. To analyze trace amounts of 1,2-unsaturated PAs in pollen products, our previously elaborated method consisting of strong cation exchange-SPE, two reduction steps followed by silylation and subsequent capillary high-resolution GC-MS using SIM mode was applied. In total, 55 commercially available pollen products were analyzed. Seventeen (31%) samples contained 1,2-unsaturated PAs in the range from 1.08 to 16.35 microg/g, calculated as retronecine equivalents. The 1,2-unsaturated PA content of pollen products is expressed in terms of a single sum parameter and no background information such as foraged plants, pollen analysis, etc. was needed to analyze the samples. The detection limit of overall procedure and the reliable quantitation limit were 0.003 and 0.01 microg/g, respectively.

  9. Pollen evidence for late pleistocene bering land bridge environments from Norton Sound, Northeastern Bering Sea, Alaska

    Science.gov (United States)

    Ager, T.A.; Phillips, R.L.

    2008-01-01

    After more than half a century of paleoenvironmental investigations, disagreements persist as to the nature of vegetation type and climate of the Bering land bridge (BLB) during the late Wisconsin (Sartan) glacial interval. Few data exist from sites on the former land bridge, now submerged under the Bering and Chukchi Seas. Two hypotheses have emerged during the past decade. The first, based on pollen data from Bering Sea islands and adjacent mainlands of western Alaska and Northeast Siberia, represents the likely predominant vegetation on the Bering land bridge during full-glacial conditions: graminoid-herb-willow tundra vegetation associated with cold, dry winters and cool, dry summer climate. The second hypothesis suggests that dwarf birch-shrub-herb tundra formed a broad belt across the BLB, and that mesic vegetation was associated with cold, snowier winters and moist, cool summers. As a step towards resolving this controversy, a sediment core from Norton Sound, northeastern Bering Sea was radiocarbon dated and analyzed for pollen content. Two pollen zones were identified. The older, bracketed by radiocarbon ages of 29,500 and 11,515 14C yr BP, contains pollen assemblages composed of grass, sedge, wormwood, willow, and a variety of herb (forb) taxa. These assemblages are interpreted to represent graminoid-herb-willow tundra vegetation that developed under an arid, cool climate regime. The younger pollen zone sediments were deposited about 11,515 14C yr BP, when rising sea level had begun to flood the BLB. This younger pollen zone contains pollen of birch, willow, heaths, aquatic plants, and spores of sphagnum moss. This is interpreted to represent a Lateglacial dwarf birch-heath-willow-herb tundra vegetation, likely associated with a wetter climate with deeper winter snows, and moist, cool summers. This record supports the first hypothesis, that graminoid-herb-willow tundra vegetation extended into the lowlands of the BLB during full glacial conditions of the

  10. Pollensomes as Natural Vehicles for Pollen Allergens.

    Science.gov (United States)

    Prado, Noela; De Linares, Concepción; Sanz, María L; Gamboa, Pedro; Villalba, Mayte; Rodríguez, Rosalía; Batanero, Eva

    2015-07-15

    Olive (Olea europaea) pollen constitutes one of the most important allergen sources in the Mediterranean countries and some areas of the United States, South Africa, and Australia. Recently, we provided evidence that olive pollen releases nanovesicles of respirable size, named generically pollensomes, during in vitro germination. Olive pollensomes contain allergens, such as Ole e 1, Ole e 11, and Ole e 12, suggesting a possible role in allergy. The aim of this study was to assess the contribution of pollensomes to the allergic reaction. We show that pollensomes exhibit allergenic activity in terms of patients' IgE-binding capacity, human basophil activation, and positive skin reaction in sensitized patients. Furthermore, allergen-containing pollensomes have been isolated from three clinically relevant nonphylogenetically related species: birch (Betula verrucosa), pine (Pinus sylvestris), and ryegrass (Lolium perenne). Most interesting, pollensomes were isolated from aerobiological samples collected with an eight-stage cascade impactor collector, indicating that pollensomes secretion is a naturally occurring phenomenon. Our findings indicate that pollensomes may represent widespread vehicles for pollen allergens, with potential implications in the allergic reaction. Copyright © 2015 by The American Association of Immunologists, Inc.

  11. Optimization of conditions for in vitro pollen germination and pollen ...

    African Journals Online (AJOL)

    Pollen germination and pollen tube growth might have a significant effect on fruit and seed production. This study was conducted to investigate the best medium for pollen germination and pollen tube growth of date palm male. Significant differences in percentages of pollen germination and pollen tube growth were ...

  12. Mapping of T cell epitopes of the major fraction of rye grass using peripheral blood mononuclear cells from atopics and non-atopics. II. Isoallergen clone 5A of Lolium perenne group I (Lol p I).

    Science.gov (United States)

    Bungy, G A; Rodda, S; Roitt, I; Brostoff, J

    1994-09-01

    Rye grass is the major cause of hay fever which currently affects 20% of the population. Lolium perenne group I (Lol p I) is a glycoprotein of 240 amino acid residues, representing the main allergen of rye grass. We have used peripheral blood mononuclear cells (PBMC) from controls and subjects allergic to rye grass and cultured them with L. perenne extract (LPE) and Lol p I and measured lymphocyte activation using thymidine incorporation. Patients were further studied against the 115 overlapping peptides of the iso-allergen clone 5A of Lol p I to see whether the 4 amino acid residue differences between clone 1A and clone 5A affect the T cell epitope and thus, lymphocyte activation. There are 24 peptide differences between isoallergen clone 1A and clone 5A occurring in pools 4, 13, 16 and 19 each one of which could be an immunodominant epitope. The PBMC from all allergic patients studied showed a strong proliferative response to LPE and Lol p I. Five immunogenic peptide pools, pool 6, 15, 16, 17 and 19 of the isoallergen clone 5A were also identified. Most of these pools are in the C-terminal region of Lol p I. Out of 20 pools tested in vitro 1 pool (pool-17) induced PBMC proliferation in five out of six patients who were not restricted to an HLA class II DR gene product. However, three out of the six subjects responded to various other peptide pools in addition to the immunodominant pool. In spite of the amino acid differences between the two clones, pool 17 still remains the immunodominant T cell epitope. Control subjects showed only weak responses to LPE and no detectable response to either Lol p I or peptide pools. From within the most active pool we have defined two peptides of the isoallergen clone 5A (identical in sequence with clone 1A) which stimulate lymphocytes from rye grass-sensitive patients in vitro. Previous studies with the two continuous sequences (193WGAVWRIDTPDK204 and 195AVWRIDTPDKLT206) tested in vivo by intradermal skin testing have shown

  13. Possible role of climate changes in variations in pollen seasons and allergic sensitizations during 27 years.

    Science.gov (United States)

    Ariano, Renato; Canonica, Giorgio Walter; Passalacqua, Giovanni

    2010-03-01

    Climate changes may affect the quality and amount of airborne allergenic pollens. The direct assessment of such an effect requires long observation periods and a restricted geographic area. To assess variations in pollens and allergic sensitizations across 27 years in relation to climate change in a specific region. We recorded pollen counts, season durations, and prevalences of sensitizations for 5 major pollens (birch, cypress, olive, grass, and Parietaria) in western Liguria between 1981 and 2007. Pollen counts were performed using a Hirst-type trap, and sensitizations were assessed by means of skin prick testing. Meteorologic data for the same period included average temperatures, direct radiation, humidity, number of sunny days, and rainfall. There was a progressive increase in the duration of the pollen seasons for Parietaria (+85 days), olive (+18 days), and cypress (+18 days), with an overall advance of their start dates. For Parietaria, there was an advance of 2 months in 2006 vs 1981. Also, the total pollen load progressively increased for the considered species (approximately 25% on average) except for grasses. Percentages of patients sensitized to the pollens increased throughout the years, whereas the percentage of individuals sensitized to house dust mite remained stable. These behaviors paralleled the constant increase in direct radiation, temperature, and number of days with a temperature greater than 30 degrees C. The progressive climate changes, with increased temperatures, may modify the global pollen load and affect the rate of allergic sensitization across long periods.

  14. The Banyan and the Birch Tree

    DEFF Research Database (Denmark)

    Lorenzen, Mark; Taeube, Florian A.

    Theoretical and empirical research on entrepreneurial networks is largely outcome-oriented and little integrated with family firm research. In this paper, we draw on social network and entrepreneurship literatures in order to investigate how family businesses build and make use of a variety of em...... compared to the plain structure of a birch tree describing Hollywood, where embedded ties can be different from familial ties....

  15. The pollen complex from postglacial sediments of the Laptev Sea as a bioindicator

    Science.gov (United States)

    Naidina, O. D.

    2014-05-01

    The first results of comparison of palynological analysis (pollen of terrestrial plants), SEM analysis of pollen morphology, and radiocarbon age dating (AMS14C) of sediments of the eastern shelf of the Laptev Sea show that the diverse taxonomic composition of pollen spectra provides an integrated idea of the vegetation and climate of the region over 11.2 calendar kiloyears. It is found that phases of the tree and shrub vegetation development (maxima of pollen of Betula sect. Nanae and Pinus s/g Haploxylon) correspond to the warm epochs in the Holocene. It is obvious that birch phytocoenoses first settled in the southern tundra subzone with increasing temperature, and then coniferous communities of forest tundra. An occurrence of pollen of shrubby birches (Nanae) suggests compliance of permafrost landscapes with cold climate conditions, i.e., with an annual average temperature of -2°C and amount of precipitation of less than 500 mm. Owing to a progressive increase in summer temperatures, dwarf cedar and pine communities advanced toward the seashore. The SEM analysis results show that a significant proportion of regional coniferous pollen belongs to representatives of Pinus pumila (Pall.) and P. sylvestris L. In addition, the SEM study of the exine of Pinus sylvestris L. and P. pumila (Pall.) Regel pollen grains confirmed polymorphism in coniferous pollen. According to the inverse relationship between climate and vegetation, frequent climate fluctuations that are typical of progressive and differential postglacial transgression were revealed. An increase in arboreal pollen transfer onto the shelf later than 9.1 cal. ka coincides with the time of forest boundary migration to the north due to the warming of the Earth's climate. At that time, the tundra vegetation was replaced by forest-tundra vegetation, the maximum stage of sea transgression began, and there appeared a trend of increasing temperature and moisture.

  16. Pollen reference collection digitization

    NARCIS (Netherlands)

    Ercan, F.E.Z.|info:eu-repo/dai/nl/41250085X; Donders, T.H.|info:eu-repo/dai/nl/290469872; Bijl, P.K.|info:eu-repo/dai/nl/314028110; Wagner, F.|info:eu-repo/dai/nl/173870783

    2016-01-01

    The extensive Utrecht University pollen reference collection holds thousands of pollen samples of many species and genera from all over the world and has been a basis for the widely-used North West European Pollen Flora. These samples are fixed on glass slides for microscopy use, but the aging

  17. Molecular characterization of Api g 1, the major allergen of celery (Apium graveolens), and its immunological and structural relationships to a group of 17-kDa tree pollen allergens.

    Science.gov (United States)

    Breiteneder, H; Hoffmann-Sommergruber, K; O'Riordain, G; Susani, M; Ahorn, H; Ebner, C; Kraft, D; Scheiner, O

    1995-10-15

    Individuals suffering from immediate hypersensitivity (type-I allergy) to a particular pollen frequently display intolerance to several foods of plant origin. In this respect, individuals sensitized to birch pollen and/or mugwort pollen frequently display type-I allergic symptoms after ingestion of celery. In this study, we expressed the major allergenic protein of celery, Api g 1, which is responsible for the birch-celery syndrome, in the form of a non-fusion protein. The open reading frame of the cDNA of Api g 1 codes for a protein of 153 amino acids with a molecular mass of 16.2 kDa and 40% identity (60% similarity) to the major allergen of birch pollen, Bet v 1. Furthermore, Api g 1 exhibited similar characteristics to (a) two proteins in parsley induced by fungal infection, (b) the major tree pollen allergens and (c) pathogenesis-related and stress-induced proteins in other plant species. The reactivity of recombinant Api g 1 with IgE antibodies present in sera from celery intolerant patients was comparable to that of the natural celery allergen. Cross-reactivity with Bet v 1 was proven by cross-inhibition experiments, which provides further support for the existence of the birch-celery syndrome and for the suggestion that allergies to some vegetable foods are epiphenomena to allergies caused by inhalation of tree pollen.

  18. Horse chestnut pollen quality

    Directory of Open Access Journals (Sweden)

    Ćalić Dušica

    2017-01-01

    Full Text Available Pollen quality of horse chestnut, expressed as pollen productivity, viability and germination was studied. Anthers of horse chestnut genotypes had pollen production from 3.66 to 5.06 x 103 pollen grains per anther, depending of genotype. Also, pollen of horse chestnut Ah1-Ah4 genotypes showed different viability (from 56 to 68%, after staining with fluorescein diacetate. Pollen germination of Ah1-Ah4 genotypes varied from 50-66% on basic medium. Inclusion of polyethylene glycol-PEG from 10%, 15% and 20% v/w increased pollen germination. The best results were achieved on medium with the largest PEG concentration. On these medium 76-91% pollen grains were germinated, depending of genotype. The best pollen quality, for all tested parameters, had genotype Ah2. Knowledge about morphology, production, viability, in vitro germination, tube growth as well as pollen: ovule ratio can be of great importance for future pollen biology studies. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173015

  19. Pollen immunotherapy reduces the development of asthma in children with seasonal rhinoconjunctivitis (the PAT-study)

    DEFF Research Database (Denmark)

    Möller, Christian; Dreborg, Sten; Ferdousi, Hosne A

    2002-01-01

    rhinoconjunctivitis. METHODS: From 6 pediatric allergy centers, 205 children aged 6 to 14 years (mean age, 10.7 years) with grass and/or birch pollen allergy but without any other clinically important allergy were randomized either to receive specific immunotherapy for 3 years or to an open control group. All...... provocation tests were carried out during the season(s) and during the winter. RESULTS: Before the start of immunotherapy, 20% of the children had mild asthma symptoms during the pollen season(s). Among those without asthma, the actively treated children had significantly fewer asthma symptoms after 3 years...

  20. Changes in the concentration of pollen over an 11-year period in a Polish urban environment

    Directory of Open Access Journals (Sweden)

    Barbara Majkowska-Wojciechowska

    2016-12-01

    Full Text Available Recent studies suggest that climate change can influence plant reproductive systems and have an impact on the increase in allergenic pollen in atmospheric air; highly allergenic pollen may intensify the allergic response in people. The aim of our study was to evaluate the seasonal dynamic concentration of the most allergenic pollen taxa, i.e., the following trees: Alnus, Corylus, Betula, and herbaceous plants: grasses (Poaceae, Artemisia, and Ambrosia, in the long-term period of 2003–2013 in the city of Lodz, Poland. Weekly airborne pollen concentrations were evaluated with a volumetric Lansoni pollen trap. The beginning and the end of the season were calculated by the 98% method. The birch (Betula pollen was at the highest level and accounted for 79%, followed by alder (Alnus – 19%, and hazel (Corylus – 2%. Among the herbaceous taxa, grasses (Poaceae pollen dominated – 79%, followed by mugwort (Artemisia – 18%, and ragweed (Ambrosia – 3%. Our findings indicate a lack of qualitative and quantitative change in the pollen produced over the 11-year period.

  1. Expression of bgt gene in transgenic birch (Betula platyphylla Suk ...

    African Journals Online (AJOL)

    Study on the characteristics of integration and expression is the basis of genetic stability of foreign genes in transgenic trees. To obtain insight into the relationship of transgene copy number and expression level, we screened 22 transgenic birch lines. Southern blot analysis of the transgenic birch plants indicated that the ...

  2. Expression of bgt gene in transgenic birch (Betula platyphylla Suk.)

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... Study on the characteristics of integration and expression is the basis of genetic stability of foreign genes in transgenic trees. To obtain insight into the relationship of transgene copy number and expression level, we screened 22 transgenic birch lines. Southern blot analysis of the transgenic birch.

  3. Induction of Eosinophilic Esophagitis by Sublingual Pollen Immunotherapy

    Directory of Open Access Journals (Sweden)

    Stephan Miehlke

    2013-09-01

    Full Text Available Sublingual immunotherapy (SLIT is increasingly investigated and utilized for the treatment of food and pollen allergies. Previous case reports suggested that eosinophilic esophagitis (EoE might develop as a long-term complication in children after completion of oral immunotherapy. Here, we describe a 44-year-old female with a medical history of pollinosis who for the first time in her life developed complete manifestation of EoE (peak eosinophils 164/high power field 4 weeks after initiation of SLIT using specific soluble allergens (hazelnut, birch, alder according to previous specific serum IgE testing. After discontinuation of SLIT, EoE resolved completely within 4 weeks without any other medical intervention. During a follow-up of 12 months the patient remained free of any esophageal symptoms. This is the first case report demonstrating a close and therefore likely causative association between pollen SLIT and EoE in an adult patient.

  4. Induction of eosinophilic esophagitis by sublingual pollen immunotherapy.

    Science.gov (United States)

    Miehlke, Stephan; Alpan, Oral; Schröder, Sören; Straumann, Alex

    2013-01-01

    Sublingual immunotherapy (SLIT) is increasingly investigated and utilized for the treatment of food and pollen allergies. Previous case reports suggested that eosinophilic esophagitis (EoE) might develop as a long-term complication in children after completion of oral immunotherapy. Here, we describe a 44-year-old female with a medical history of pollinosis who for the first time in her life developed complete manifestation of EoE (peak eosinophils 164/high power field) 4 weeks after initiation of SLIT using specific soluble allergens (hazelnut, birch, alder) according to previous specific serum IgE testing. After discontinuation of SLIT, EoE resolved completely within 4 weeks without any other medical intervention. During a follow-up of 12 months the patient remained free of any esophageal symptoms. This is the first case report demonstrating a close and therefore likely causative association between pollen SLIT and EoE in an adult patient.

  5. Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease

    Science.gov (United States)

    Zhang, R.; Duhl, T.; Salam, M. T.; House, J. M.; Flagan, R. C.; Avol, E. L.; Gilliland, F. D.; Guenther, A.; Chung, S. H.; Lamb, B. K.; VanReken, T. M.

    2014-03-01

    Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF/CMAQ) modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California (USA) for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to

  6. Isoform identification and characterization of Art v 3, the lipid-transfer protein of mugwort pollen.

    Science.gov (United States)

    Gadermaier, Gabriele; Harrer, Andrea; Girbl, Tamara; Palazzo, Paola; Himly, Martin; Vogel, Lothar; Briza, Peter; Mari, Adriano; Ferreira, Fatima

    2009-06-01

    Art v 3, the lipid-transfer protein (LTP) of Artemisia vulgaris pollen is a relevant allergen showing frequent cross-reactivity with homologues in other plants. Here we report the identification of four full-length Art v 3 sequences obtained by cDNA cloning using mass spectrometry-based sequencing. Two isoforms, Art v 3.0201 and Art v 3.0301 were expressed as soluble proteins in Escherichia coli Rosetta-gami B(DE3) pLysS using different expression systems. Purified natural and recombinant Art v 3 demonstrated similar secondary structures in circular dichroism analysis. All preparations showed high thermal stability but low resistance to gastric digestion with pepsin. Patient-specific IgE reactivity patterns to natural or recombinant isoallergens were observed among Art v 3-sensitized subjects. Using Immuno Solid-phase Allergen Chip (ISAC) assays, frequent cross-reactivity of Art v 3 with LTPs from peach and hazelnut was shown. The biological activity of both isoforms was comparable to the natural allergen in basophil release assays. The newly identified sequences provide the basis for recombinant mugwort LTP production enabling batch-to-batch reproducibility and thus ensuring high-quality products for diagnosis and therapy.

  7. Aerobiological study of pollen and mold in Seoul, Korea

    Directory of Open Access Journals (Sweden)

    Jae-Won Oh

    1998-01-01

    Full Text Available In a large number of allergic individuals, inhalant allergens are important causative and triggering agents in respiratory allergies. It is essential to survey the pollen and mold around the patient’s environment for the diagnosis and treatment of airborne allergy. Rotorod samplers were installed at well-ventilated places in seven collecting stations in Seoul, the capital of Korea, which has a population of 12 million. Airborne particles carrying allergens were collected daily from each station for 2 years (1 October 1995 to 30 September 1997. After being stained with Calberla’s fuchsin, they were identified, counted and recorded. The weather in Seoul was also recorded. Pollen was found from the middle of February through to the end of December. The peak date for pollen was 12 May (peak mean daily count: 701 grains/m3/day and for mold it was 23 June (peak mean daily count: 936 spores/m3/day. Alder, birch, pine, oak, maple, elm, juniper, willow, and gingko trees were prevalent during the tree season, lasting from the middle of February to late July. Then sagebrush, ragweed, Japanese hop, and pigweed followed during the weed season, which lasts from the middle of July to the end of December. In skin prick test results, house dust mite was the most common positive allergen in Seoul, followed by cockroach. Among the pollens, mugwort was the most common positive, followed by ragweed mix, alder, birch, and grasses mix. Among the molds, there were high counts of Cladosporium and Alternaria during the year, excluding January. Ascospore of Lepto-spheria was highest during the monsoon season.

  8. BIRCH: A user-oriented, locally-customizable, bioinformatics system

    Directory of Open Access Journals (Sweden)

    Fristensky Brian

    2007-02-01

    Full Text Available Abstract Background Molecular biologists need sophisticated analytical tools which often demand extensive computational resources. While finding, installing, and using these tools can be challenging, pipelining data from one program to the next is particularly awkward, especially when using web-based programs. At the same time, system administrators tasked with maintaining these tools do not always appreciate the needs of research biologists. Results BIRCH (Biological Research Computing Hierarchy is an organizational framework for delivering bioinformatics resources to a user group, scaling from a single lab to a large institution. The BIRCH core distribution includes many popular bioinformatics programs, unified within the GDE (Genetic Data Environment graphic interface. Of equal importance, BIRCH provides the system administrator with tools that simplify the job of managing a multiuser bioinformatics system across different platforms and operating systems. These include tools for integrating locally-installed programs and databases into BIRCH, and for customizing the local BIRCH system to meet the needs of the user base. BIRCH can also act as a front end to provide a unified view of already-existing collections of bioinformatics software. Documentation for the BIRCH and locally-added programs is merged in a hierarchical set of web pages. In addition to manual pages for individual programs, BIRCH tutorials employ step by step examples, with screen shots and sample files, to illustrate both the important theoretical and practical considerations behind complex analytical tasks. Conclusion BIRCH provides a versatile organizational framework for managing software and databases, and making these accessible to a user base. Because of its network-centric design, BIRCH makes it possible for any user to do any task from anywhere.

  9. BIRCH: a user-oriented, locally-customizable, bioinformatics system.

    Science.gov (United States)

    Fristensky, Brian

    2007-02-09

    Molecular biologists need sophisticated analytical tools which often demand extensive computational resources. While finding, installing, and using these tools can be challenging, pipelining data from one program to the next is particularly awkward, especially when using web-based programs. At the same time, system administrators tasked with maintaining these tools do not always appreciate the needs of research biologists. BIRCH (Biological Research Computing Hierarchy) is an organizational framework for delivering bioinformatics resources to a user group, scaling from a single lab to a large institution. The BIRCH core distribution includes many popular bioinformatics programs, unified within the GDE (Genetic Data Environment) graphic interface. Of equal importance, BIRCH provides the system administrator with tools that simplify the job of managing a multiuser bioinformatics system across different platforms and operating systems. These include tools for integrating locally-installed programs and databases into BIRCH, and for customizing the local BIRCH system to meet the needs of the user base. BIRCH can also act as a front end to provide a unified view of already-existing collections of bioinformatics software. Documentation for the BIRCH and locally-added programs is merged in a hierarchical set of web pages. In addition to manual pages for individual programs, BIRCH tutorials employ step by step examples, with screen shots and sample files, to illustrate both the important theoretical and practical considerations behind complex analytical tasks. BIRCH provides a versatile organizational framework for managing software and databases, and making these accessible to a user base. Because of its network-centric design, BIRCH makes it possible for any user to do any task from anywhere.

  10. Establishing an Alaskan birch syrup industry: Birch Syrup—It’s the Un-maple!TM

    Science.gov (United States)

    Marlene. Cameron

    2001-01-01

    Ten years ago a small group of Alaskans began commercial production of birch syrup from the sap of the paper birch, Betula papyrifera, and established an industry that is expanding in response to demand and has the potential to make a significant contribution to Alaska's economy. There are still many problems to be solved; research and...

  11. 75 FR 51987 - Birch Power Company and Sorenson Engineering; Birch Power Company and Sorenson Leasing L.L.C...

    Science.gov (United States)

    2010-08-24

    ... Company and Sorenson Engineering; Birch Power Company and Sorenson Leasing L.L.C.; Notice of Application... Leasing, L.L.C. (transferees) filed an application for transfer of license for the Birch Creek... Sorenson Leasing L.L.C., 5203 South 11th East, Idaho Falls, Idaho 83404, phone (208) 589-6908. FERC Contact...

  12. Regional Difference of Causative Pollen in Children with Allergic Rhinitis

    Science.gov (United States)

    2017-01-01

    The aim of this study was to investigate role of common pollen in Korean school-aged children with allergic rhinitis (AR) in 5 provinces (Incheon Metropolitan City-Gyeonggi Province, Chungcheongbuk-do, Gwangju Metropolitan City, Busan Metropolitan City, and Jeju Special Self-Governing Province), using a questionnaire and skin prick test, and to assess the differences among the residential regions. Among the enrolled 14,678 total children, 1,641 (22.0%) had AR. The sensitization rate to pollen (38.7%) was the second highest among examined allergens and significant differences were in the sensitization rates to trees, weeds, and grasses among the 5 provinces (P < 0.05). The sensitization to trees (25.2%) was the highest common among the pollen types and significant differences also were observed in the sensitization rates to alder, birch, Japanese cedar, oak, and elm among the 5 provinces. The sensitization rate to weeds (19.9%) was the second highest and significant differences were observed in the sensitization rate to Japanese hop, mugwort, and ragweed among the 5 provinces. The sensitization rate to house dust mite was 86.8%, the highest among examined allergens and that to Dermatophagoides farinae exhibited regional differences (P = 0.003) but not to D. farinae (P = 0.584). The sensitization rate to mold (13.5%) was the highest in Jeju and lowest in Busan, and a statistically significant difference was detected among the 5 provinces. These results support that examined pollen allergens are strongly associated with residential region due to regional causative pollen differences among children with AR within Korea to investigate the main pollen allergens. PMID:28480649

  13. Age-dependent sensitization to the 7S-vicilin-like protein Cor a 11 from hazelnut (Corylus avellana) in a birch-endemic region.

    Science.gov (United States)

    Verweij, M M; Hagendorens, M M; Trashin, S; Cucu, T; De Meulenaer, B; Devreese, B; Bridts, C H; De Clerck, L S; Ebo, D G

    2012-01-01

    Hazelnut (Corylus avellana) allergy exhibits age and geographically distinct sensitization patterns that have not yet been fully resolved. To study sensitization to Cor a 11 in different age groups of hazelnut-allergic patients and infants with atopic dermatitis (AD) sensitized to hazelnut in a birch-endemic region. Sera from 80 hazelnut-allergic patients, 33 infants under 1 year of age with AD (24 sensitized and 9 not sensitized to hazelnut), 32 healthy control individuals, and 29 birch pollen-allergic but hazelnut-tolerant individuals were tested for immunoglobulin (Ig) E reactivity to Cor a 11 by ImmunoCAP. IgE reactivity to Cor a 1.01, Cor a 1.04, Cor a 8, and Cor a 9 was studied by ISAC microarray. Forty patients (22 preschool children, 10 schoolchildren, and 8 adults) with systemic reactions on consumption of hazelnut were sensitized to Cor a 11 (respective rates of 36%, 40%, and 12.5%). Forty patients (6 preschool children, 10 schoolchildren, and 24 adults) reported oral allergy syndrome but only 2 of them (of preschool age) were sensitized to Cor a 11. Two (8%) of the AD infants sensitized to hazelnut showed IgE reactivity to Cor a 11. This reactivity was not observed in any of the AD infants without sensitization to hazelnut, in any of the birch-pollen allergic patients without hazelnut allergy, or in any of the healthy control individuals. Sensitization to Cor a 11 in a birch-endemic region is predominantly found in children with severe hazelnut allergy, a finding that is consistent with observations concerning sensitization to Cor a 9.

  14. Grass pollen symptoms interfere with the recollection of birch pollen symptoms - a prospective study of suspected, asymptomatic skin sensitization

    DEFF Research Database (Denmark)

    Assing, K; Bodtger, U; Poulsen, Lars K.

    2007-01-01

    Asymptomatic skin sensitization (AS) is a risk factor for the development of allergic symptoms. A meticulous definition of this condition requires a systematic assessment of clinical symptoms before inclusion....

  15. Long-Term Storage of Yellow and Paper Birch Seed

    Science.gov (United States)

    Knud E. Clausen

    1975-01-01

    Storage of yellow and paper birch seeds for 12 years does not appear practical but seed visibility can usually be maintained for at least 8 years, if the seeds are kept in closed containers at 36? to 40?F.

  16. Gnomonia canker, shoot blight, and leaf spot of yellow birch.

    Science.gov (United States)

    Kenneth J. Jr. Kessler

    1978-01-01

    Describes a canker, shoot blight, and leaf spot disease of yellow birch seedlings in the northern Great Lakes region and tells how and when trees become infected by the fungal causal agent, Gnomonia setacea.

  17. How honey bees carry pollen

    Science.gov (United States)

    Matherne, Marguerite E.; Anyanwu, Gabriel; Leavey, Jennifer K.; Hu, David L.

    2017-11-01

    Honey bees are the tanker of the skies, carrying thirty percent of their weight in pollen per foraging trip using specialized orifices on their body. How do they manage to hang onto those pesky pollen grains? In this experimental study, we investigate the adhesion force of pollen to the honeybee. To affix pollen to themselves, honey bees form a suspension of pollen in nectar, creating a putty-like pollen basket that is skewered by leg hairs. We use tensile tests to show that the viscous force of the pollen basket is more than ten times the honeybee's flight force. This work may provide inspiration for the design of robotic flying pollinators.

  18. Holocene pollen record from Lake Sokoch, interior Kamchatka (Russia), and its paleobotanical and paleoclimatic interpretation

    Science.gov (United States)

    Dirksen, Veronika; Dirksen, Oleg; van den Bogaard, Christel; Diekmann, Bernhard

    2015-11-01

    A pollen record, obtained from sediments of Lake Sokoch in mountain interior of the Kamchatka Peninsula, covers the last ca. 9600 years (all ages are given in calibrated years BP). Variations in local components, including pollen, spores and non-pollen palynomorphs, and related changes in sedimentation document the lake development from initially seepage and shallow basin to deeper lake during the mid Holocene and then to the hydrologically open system during the late Holocene. The studies of volcanic ashes from the lake sediment core show their complex depositional histories. Lake Sokoch occupies a former proglacial basin between two terminal moraines of the LGM time. The undated basal part of record before ca. 9600 year BP, however, does not reflect properly cold conditions. At that time, although shrublands and tundra dominated, stone birch and white birch forests have already settled in surroundings; the presence of alder woodland indicates wet and maritime-like climate. The subsequent forest advance suggesting warmer conditions was interrupted by the ca. 8000-7600 year BP spell of cooler climate. The following culmination of warmth is bracketed by the evidence of the first maximal forest extent between ca. 7400 and 5100 year BP. During that time, dramatic retreat of alder forest suggests a turn from maritime-like to more continental climate conditions. The cool and wet pulse after ca. 5100 year BP was pronounced as forests retreat while shrublands, meadows and bogs extended. An expansion of white birch forest since ca. 3500 year BP reflected the onset of drier climate, strengthening continentality and seasonal contrast. The second maximum of forests dominated by both stone and white birches occurred between ca. 2200 and 1700 year BP and indicated warming in association with relatively dry and increasingly continental climate. The following period was wetter and cooler, and minor outbreak of alder forest around ca. 1500 year BP suggests a short-term return of

  19. Allergies, asthma, and pollen

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000489.htm Allergies, asthma, and pollen To use the sharing features ... this page, please enable JavaScript. Things that make allergies or asthma worse are called triggers. It is ...

  20. Clinical efficacy of sublingual and subcutaneous birch pollen allergen-specific immunotherapy

    DEFF Research Database (Denmark)

    Khinchi, M S; Poulsen, Lars K.; Carat, F

    2004-01-01

    Both sublingual allergen-specific immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) have a documented clinical efficacy, but only few comparative studies have been performed.......Both sublingual allergen-specific immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) have a documented clinical efficacy, but only few comparative studies have been performed....

  1. Dynamic Behaviour of Birch and Sequoia at High Strain Rates

    Science.gov (United States)

    Bragov, A. M.; Lomunov, A. K.; Sergeichev, I. V.; Gray, G. T.

    2006-07-01

    This paper presents results of the dynamic mechanical response of for two structural woods, i.e. birch and sequoia. Monotonic and cyclic compression testing at room temperature of these materials was performed using a modified Kolsky method; a 20-mm diameter split-Hopkinson pressure bar (SHPB). The birch and sequoia specimens were loaded parallel and orthogonal to the grain of the wood, as well as, at other angles relative to the wood grain. The dynamic mechanical behavior of the two woods was measured as a function of loading orientation under a uniaxial stress state as well as under circumferential confinement using a collar surrounding the sample to quantify the effect of lateral confinement on mechanical behavior. The loading and unloading responses of both woods were found to exhibit nonlinear behavior and a strong dependency on the strain rate of loading. The dynamic stress-strain responses of the birch and sequoia showed a strong influence of grain orientation of the flow stress and fracture behavior. Examination of the damage evolution and fracture responses of the birch and sequoia displayed a strong dependence on grain orientation. Cyclic dynamic loading data, obtained using a modification of the original SHPB testing method, is also presented for the two structural woods studied. In addition to the SHPB tests, plane-wave Shockwave loading experiments were conducted and the shock adiabates for birch was obtained.

  2. Budburst phenology of white birch in industrially polluted areas

    International Nuclear Information System (INIS)

    Kozlov, Mikhail V.; Eraenen, Janne K.; Zverev, Vitali E.

    2007-01-01

    Effects of environmental contamination on plant seasonal development have only rarely been properly documented. Monitoring of leaf growth in mountain birch, Betula pubescens subsp. czerepanovii, around a nickel-copper smelter at Monchegorsk hinted advanced budburst phenology in most polluted sites. However, under laboratory conditions budburst of birch twigs cut in late winter from trees naturally growing around three point polluters (nickel-copper smelter at Monchegorsk, aluminium factory at Kandalaksha, and iron pellet plant at Kostomuksha) showed no relationship with distance from the emission source. In a greenhouse experiment, budburst phenology of mountain birch seedlings grown in unpolluted soil did not depend on seedling origin (from heavily polluted vs. clean sites), whereas seedlings in metal-contaminated soil demonstrated delayed budburst. These results allow to attribute advanced budburst phenology of white birch in severely polluted sites to modified microclimate, rather than to pollution impact on plant physiology or genetics. - Advanced budburst phenology in white birch in severely polluted sites is explained by modified microclimate, not by pollution impact on plant physiology

  3. RELATIONSHIP BETWEEN RECENT POLLEN DEPOSITION AND AIRBORNE POLLEN CONCENTRATION

    NARCIS (Netherlands)

    SPIEKSMA, FTM; NIKKELS, BH; BOTTEMA, S

    In the reconstruction of past or recent vegetation the study of deposited pollen plays an important role. As reference value, very often the pollen content of moss polsters (''moss cushions'') is assessed to estimate the pollen deposition (''influx'') from the air. Recently, the data from

  4. Comparative long-term trend analysis of daily weather conditions with daily pollen concentrations in Brussels, Belgium

    Science.gov (United States)

    Bruffaerts, Nicolas; De Smedt, Tom; Delcloo, Andy; Simons, Koen; Hoebeke, Lucie; Verstraeten, Caroline; Van Nieuwenhuyse, An; Packeu, Ann; Hendrickx, Marijke

    2018-03-01

    A clear rise in seasonal and annual temperatures, a gradual increase of total radiation, and a relative trend of change in seasonal precipitation have been observed for the last four decades in Brussels (Belgium). These local modifications may have a direct and indirect public health impact by altering the timing and intensity of allergenic pollen seasons. In this study, we assessed the statistical correlations (Spearman's test) between pollen concentration and meteorological conditions by using long-term daily datasets of 11 pollen types (8 trees and 3 herbaceous plants) and 10 meteorological parameters observed in Brussels between 1982 and 2015. Furthermore, we analyzed the rate of change in the annual cycle of the same selected pollen types by the Mann-Kendall test. We revealed an overall trend of increase in daily airborne tree pollen (except for the European beech tree) and an overall trend of decrease in daily airborne pollen from herbaceous plants (except for Urticaceae). These results revealed an earlier onset of the flowering period for birch, oak, ash, plane, grasses, and Urticaceae. Finally, the rates of change in pollen annual cycles were shown to be associated with the rates of change in the annual cycles of several meteorological parameters such as temperature, radiation, humidity, and rainfall.

  5. Comparative long-term trend analysis of daily weather conditions with daily pollen concentrations in Brussels, Belgium

    Science.gov (United States)

    Bruffaerts, Nicolas; De Smedt, Tom; Delcloo, Andy; Simons, Koen; Hoebeke, Lucie; Verstraeten, Caroline; Van Nieuwenhuyse, An; Packeu, Ann; Hendrickx, Marijke

    2017-10-01

    A clear rise in seasonal and annual temperatures, a gradual increase of total radiation, and a relative trend of change in seasonal precipitation have been observed for the last four decades in Brussels (Belgium). These local modifications may have a direct and indirect public health impact by altering the timing and intensity of allergenic pollen seasons. In this study, we assessed the statistical correlations (Spearman's test) between pollen concentration and meteorological conditions by using long-term daily datasets of 11 pollen types (8 trees and 3 herbaceous plants) and 10 meteorological parameters observed in Brussels between 1982 and 2015. Furthermore, we analyzed the rate of change in the annual cycle of the same selected pollen types by the Mann-Kendall test. We revealed an overall trend of increase in daily airborne tree pollen (except for the European beech tree) and an overall trend of decrease in daily airborne pollen from herbaceous plants (except for Urticaceae). These results revealed an earlier onset of the flowering period for birch, oak, ash, plane, grasses, and Urticaceae. Finally, the rates of change in pollen annual cycles were shown to be associated with the rates of change in the annual cycles of several meteorological parameters such as temperature, radiation, humidity, and rainfall.

  6. Root-Crown Relations of Young Sugar Maple and Yellow Birch

    Science.gov (United States)

    Carl H. Tubbs

    1977-01-01

    Young forest-grown sugar maple and yellow birch (1 to 6 inches d.b.h.) crowns were mapped and roots excavated. Crown dimensions were compared. Sugar maple roots usually terminated within a few feet of the crown perimeter. Yellow birch roots frequently terminated well outside crown perimeters and roots of birch were more irregularly distributed than those of maple....

  7. Consumer preferences and willingness to pay for character-marked cabinets from Alaska birch.

    Science.gov (United States)

    Geof Donovan; David. Nicholls

    2003-01-01

    Alaska birch lumber has a higher occurrence of defects (knots, bark pockets, flecks, spalting, etc.) when compared to competing hardwoods. These defects are a disadvantage when birch lumber is graded under standard National Hardwood Lumber Association (NHLA) grading rules. This paper examines whether defects and other character markings found in birch lumber may be an...

  8. Mycobionta of birch and birch stump roots and its possible effect on the infection by Armillaria spp. I.

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśna

    2014-08-01

    Full Text Available Zygorhynchus moelleri was the dominating species on/in roots of 2 year-old stumps of the 49 year-old birches. Trichoderma viride was more frequently found in the fine roots of living birches than in the fine roots of stumps though its population increased in thick roots of stumps. Occasionally the fungus also occurred on the surface of fine roots of stumps. Z. moelleri is known to produce indole 3-ethanol and indole-3 acetic acid which stimulate the growth of A. ostoyae rhizomorphs and phenoloxidizing enzymes which play an important role in the degradation of the wood. It seems that the accumulation of Z. moelleri and absence of bigger populations of T. viride on/in roots of 2-year-old stumps of the 49 year-old birches may result in an increase of their susceptibility to Armillaria infection.

  9. Hybridizing pines with diluted pollen

    Science.gov (United States)

    Robert Z. Callaham

    1967-01-01

    Diluted pollens would have many uses by the tree breeder. Dilutions would be particularly advantageous in making many controlled pollinations with a limited amount of pollen. They also would be useful in artificial mass pollinations of orchards or single trees. Diluted pollens might help overcome troublesome genetic barriers to crossing. Feasibility o,f using diluted...

  10. Germination and storage of pollen

    NARCIS (Netherlands)

    Visser, T.

    1955-01-01

    Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution

  11. Characteristics of T-cell and B-cell immune respoonses to pollen allergens in Bulgarian patients with pollinosis

    Directory of Open Access Journals (Sweden)

    ZHIVKA KOSTOVA

    2015-12-01

    Full Text Available Characterization of the pollen allergens and identification of the main T-cell and B-cell epitopes is of crucial importance, since the clarification of the cellular and molecular mechanisms will allow long-term control of this type allergic diseases and development of safe immunotherapeutic medication. The objective of this study was to identify which pollen allergens are responsible for the T-cell activation in atopic patients with pollinosis and to determine whether the same allergens are responsible for the IgE-mediated reactions. Thirty-seven patients with pollinosis and thirteen non-allergic subjects were recruited. Peripheral blood samples were collected out of the pollen season. T-cell responses (IFN-γ production towards different pollen allergens and levels of pollen specific IgE and IgG in the sera were measured by ELISA. The T-cell reactivity in most patients was directed towards the grass pollen B1, tree pollen I and autumn pollen B5. 70% of the allergic individuals responded to allergens from Lolium perenne, 84% to Dactylis glomerata, 11% to Phleum pratense, 65% to Betula pendula and 70% to Taxus baccata. Elevated serum levels of specific IgE in the allergic patients (p<0.01 were measured against the tree pollen I and autumn pollen, which include widespread deciduous trees (birch, willow, poplar and yew and Artemisia absinthium, respectively. Our results show that the T-cell reactivity and antibody responses may be directed towards different or the same allergens. In addition, we propose that short synthetic peptides, which contain overlapping T- and B-cell epitopes can be used for specific immunotherapy treatment if they lack antibody recognition domains.

  12. Pollen immunotherapy reduces the development of asthma in children with seasonal rhinoconjunctivitis (the PAT-study)

    DEFF Research Database (Denmark)

    Möller, Christian; Dreborg, Sten; Ferdousi, Hosne A

    2002-01-01

    BACKGROUND: Children with allergic rhinitis are likely to develop asthma. OBJECTIVE: The purpose of this investigation was to determine whether specific immunotherapy can prevent the development of asthma and reduce bronchial hyperresponsiveness in children with seasonal allergic...... rhinoconjunctivitis. METHODS: From 6 pediatric allergy centers, 205 children aged 6 to 14 years (mean age, 10.7 years) with grass and/or birch pollen allergy but without any other clinically important allergy were randomized either to receive specific immunotherapy for 3 years or to an open control group. All...

  13. Some physical and mechanical properties of African birch ...

    African Journals Online (AJOL)

    The use of locally manufactured or waste materials in structural buildings without loss of performance is very crucial to the growth of developing countries. This report provides the results of some physical and mechanical property tests carried out on air dried African birch (Anogeissus leiocarpus) timber grown in Nigeria.

  14. Timber resource of Minnesota's Aspen-Birch Unit, 1977.

    Science.gov (United States)

    John S. Jr. Spencer; Arnold J. Ostrom

    1979-01-01

    The fourth inventory of Minnesota's Aspen-Birch Unit shows solid gains in growing-stock and sawtimber volumes between 1962 and 1977, but a 13% decline in commercial forest area. This report gives statistical highlights and contains detailed tables of forest area a well as timber volume, growth, mortality, ownership, and use.

  15. Paper birch (Wiigwaas) of the Lake States, 1980-2010

    Science.gov (United States)

    W. Keith Moser; Mark H. Hansen; Dale Gormanson; Jonathan Gilbert; Alexandra Wrobel; Marla R. Emery; Michael J. Dockry

    2015-01-01

    Data on paper birch (Betula papyrifera L.; wiigwaas in the Ojibwe language), collected by the Forest Inventory and Analysis (FIA) program of the U.S. Forest Service on forested lands in the Great Lakes region (Michigan, Minnesota, and Wisconsin) from 1980 through 2010, are reported. Also presented are results and analysis of a supplemental inventory...

  16. Modern pollen and stomate deposition in lake surface sediments from across the treeline on the Kola Peninsula, Russia.

    Science.gov (United States)

    Gervais, B R.; MacDonald, G M.

    2001-04-01

    We sampled and analyzed surface sediments from 31 lakes along a latitudinal transect crossing the coniferous treeline on the Kola Peninsula, Russia. The major vegetation zones along the transect were tundra, birch-forest tundra, pine-forest tundra, and forest. The results indicate that the major vegetation types in our study area have distinct pollen spectra. Sum-of-squares cluster analysis and principal components analysis (PCA) groupings of pollen sites correspond to the major vegetation zones. PCA ordination of taxa indicates that the first axis separates taxa typical of the forest zone (Pinus, Picea) from taxa typical of tundra and forest-tundra zones (Polypodiaceae, Ericaceae, and Betula). The current position of the coniferous treeline, defined in our region by Pinus sylvestris, occurs roughly where Pinus pollen values reach 35% or greater. Arboreal pollen (AP)/non-arboreal pollen (NAP) ratios were calculated for each site and plotted against geographic distance along the transect. AP/NAP ratios of 7 or greater are found within pine-forest tundra and forest vegetation zones. Pinus stomates (dispersed stomatal guard cells) are absent from sites north of the coniferous treeline and all but two samples from the forested sites contain stomates. Stomate concentrations among the samples are highly variable and range from 10 to 458 per ml and positively correlate with the changing Pinus pollen values.

  17. Grass Pollen Allergens

    Science.gov (United States)

    Augustin, Rosa

    1959-01-01

    Heat and pH stability studies and experiments with organic solvents show that the A-antigens discussed in the preceding paper (Augustin, 1959c) are much more labile than the I- (`inner ring') antigens. Breakdown products and/or aggregates are produced which no longer precipitate with antisera to the original extracts, but act as inhibitors. Solutions of pollen allergens, on the other hand, are found to withstand even autoclaving for 15 min. at 20 atm. and vigorous boiling over the naked flame of a bunsen burner. None of the carbohydrates tested has a demonstrable effect on skin reactivity which is, however, destroyed by crystalline pepsin, crystalline trypsin, a crystalline mould protease and a tissue protease (a partially purified extract from rabbit spleen). It follows that the bulk of the allergens—if not all—are proteins. The relation of skin reactivity, immuno-electrophoretic patterns, carbohydrate and protein reactions to the selective destruction of the pollen antigens is investigated. Pollen components prove to have a somewhat wider range of electrophoretic mobilities than serum proteins and are probably as complicated a mixture. The most and least highly negatively charged components are without skin reactivity in allergic subjects. The skin reactive allergens appear to have the mobilities of α- and β-globulins. Not all the hay fever subjects react equally to all the components, and Cocksfoot and Timothy activity patterns vary in different subjects. ImagesFIG. 5 PMID:13795119

  18. Acute toxicity of birch tar oil on aquatic organisms

    Directory of Open Access Journals (Sweden)

    M. HAGNER

    2008-12-01

    Full Text Available Birch tar oil (BTO is a by-product of processing birch wood in a pyrolysis system. Accumulating evidence suggests the suitability of BTO as a biocide or repellent in terrestrial environments for the control of weeds, insects, molluscs and rodents. Once applied as biocide, BTO may end up, either through run-off or leaching, in aquatic systems and may have adverse effects on non-target organisms. As very little is known about the toxicity of BTO to aquatic organisms, the present study investigated acute toxicity (LC50/EC50 of BTO for eight aquatic organisms. Bioassays with the Asellus aquaticus (crustacean, Lumbriculus variegatus (oligochaeta worm, Daphnia magna (crustacean, Lymnea sp. (mollusc, Lemna minor (vascular plant, Danio rerio (fish, Scenedesmus gracilis (algae, and Vibrio fischeri (bacterium were performed according to ISO, OECD or USEPA-guidelines. The results indicated that BTO was practically nontoxic to most aquatic organisms as the median effective BTO concentrations against most organisms were >150 mg L-1. In conclusion, our toxicity tests showed that aquatic organisms are to some extent, invariably sensitive to birch tar oil, but suggest that BTO does not pose a severe hazard to aquatic biota. We deduce that, unless BTOs are not applied in the immediate vicinity of water bodies, no special precaution is required.;

  19. SUBLINGUAL SPECIFIC IMMUNOTHERAPY IN THE TREATMENT OF HAY FEVER CAUSED BY TREE POLLEN IN CHILDREN

    Directory of Open Access Journals (Sweden)

    I.M. Gaiduk

    2008-01-01

    Full Text Available The results of the investigation of effectiveness and safety of sublingual allergen specific immunotherapy (slit with tree pollen mixture for hay fever treatment in children are presented in the article. 42 children 4 to 18 years old with hay fever (allergic rhinoconjunctivitis, pollen asthma were included in the study. Birch, alder and hazel pollen sensitization was proved by skin prick test (positive in 5 patients and strongly positive in 37. 2 courses of slit out of flowering season were conducted in every child. Total dose of allergen was 43321 ± 73 PNU (3990 to 120 000 PNU after 1st course of slit, and 93 850 ± 128 PNU (8750 to 249 000 PNU after 2nd course. Effectiveness of the 1st course of slit was 3,5 points out of 4,0 and of the 2nd course — 3,8 points. Disease remission was registered in 59,5% patients after the 1st course of slit and in 83,3% patients after the 2nd course. Local side effects (tongue and throat itching, nausea and o edema of lips and systemic side effects (rhinorrhea, eye itching, fatiguability and bronchospasm of mild severity did not lead to treatment cessation. Slit is highly effective and safe method for hay fever treatment in children.Key words: pollen sensitization, sublingual allergen specific immunotherapy, children.

  20. Pollen characteristics and in vitro pollen germination of Cedrus ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... Sources1020: Ankara Üniversitesi Ziraat Fakultesi Yayinlari, Ankara p.155. Siregar IB, Sweet GB (2000).The Impact of extraction and storage conditions on the viability of radiata pine pollen. Silva Genetica, 49: 10-14. Stairs GR, Troendle V (1967). Male bud pollen radiosensitivity in selected conifer Species.

  1. Pollen characteristics and in vitro pollen germination of Cedrus ...

    African Journals Online (AJOL)

    This study aims to determine the germination characteristics, pollen tube developments, effects of germination media and temperature and incubation durations of the pollens obtained from the four clones (11342, 11344, 11345 and 11351) of Cedrus libani A. Rich. (Lebanon Cedrus) obtained from clonal seed orchard (with ...

  2. Mycobionta of birch and birch stump roots and its possible effect on the infection by Armillaria spp. II.

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśna

    2014-08-01

    Full Text Available This paper presents the differences in size and structure of mycobionta communities occurring in soil and on/i n roots of a 30 year-old birch and its stumps 2 years after cutting of the trees. Special attention was paid to the occurrence of Zygorhynchus moelleri and Trichoderma viride. The first species due to the metabolites produced may presumably stimulate the infection by Armlllaria. The second species is a well-known antagonist of Armillaria, Z. moelleri accounted only for 2.6, l.3 and 9.l % of the total number of isolates in rhizoplane as well as in the fine and thick roots of stumps, respectively. Trlchodcrma viride and T. virens were present in roots of Hve birch and its stumps only occasionally. The relatively big population of Mycelium radicis atrovirens- particularly in the fine roots of stumps is attributed to their high vitality and relatively lower level of root decomposition. It seems that the rate of stump root decomposilion does not favour their colonization by Z. moelleri and its supposed contribution in enhancing the infection by Armillaria might not be so distinct as on stumps of 49-year-old birches.

  3. Increase in pollen sensitization in Swedish adults and protective effect of keeping animals in childhood.

    Science.gov (United States)

    Bjerg, A; Ekerljung, L; Eriksson, J; Näslund, J; Sjölander, S; Rönmark, E; Dahl, Å; Holmberg, K; Wennergren, G; Torén, K; Borres, M P; Lötvall, J; Lundbäck, B

    2016-10-01

    To date, most studies of the 'allergy epidemic' have been based on self-reported data. There is still limited knowledge on time trends in allergic sensitization, especially among adults. To study allergic sensitization, its risk factors and time trends in prevalence. Within West Sweden Asthma Study (WSAS), a population-based sample of 788 adults (17-60 years) underwent skin prick tests (SPTs) for 11 aeroallergens 2009-2012. Specific IgE was analysed in 750 of the participants. Those aged 20-46 years (n = 379) were compared with the European Community Respiratory Health Survey sample aged 20-46 year from the same area (n = 591) in 1991-1992. Among those aged 20-46 years, the prevalence of positive SPT to pollen increased, timothy from 17.1% to 29.0% (P < 0.001) and birch from 15.6% to 23.7% (P = 0.002) between 1991-1992 and 2009-2012. Measurements of specific IgE confirmed these increases. Prevalence of sensitization to all other tested allergens was unchanged. In the full WSAS sample aged 17-60 years, any positive SPT was seen in 41.9%, and the dominating sensitizers were pollen (34.3%), animals (22.8%) and mites (12.6%). Pollen sensitization was strongly associated with rhinitis, whereas indoor allergens were more associated with asthma. Growing up with livestock or furred pets decreased the risk of sensitization, adjusted odds ratio 0.53 (0.28-0.995) and 0.68 (0.47-0.98), respectively. Pollen sensitization has increased in Swedish adults since the early 1990s, while the prevalence of sensitization to other allergens has remained unchanged. This is one plausible explanation for the increase in rhinitis 1990-2008 in Swedish adults, during which time the prevalence of asthma, which is more associated with perennial allergens, was stable. Contact with animals in childhood seems to reduce the risk of sensitization well into adulthood. One major factor contributing to the rise in pollen allergy is a significant increase in levels of birch and grass pollen over the past

  4. Pollen rain and pollen representation across a forest-páramo ecotone in northern Ecuador

    NARCIS (Netherlands)

    Moscol Olivera, M.; Duivenvoorden, J.F.; Hooghiemstra, H.

    2009-01-01

    Modern pollen spectra were studied in forest and páramo vegetation from the Guandera area, northern Ecuador. Pollen representation was estimated by comparing the presence of plant taxa from a recent vegetation survey with the pollen spectra in moss polsters and pollen traps. In total, 73 pollen taxa

  5. CHARACTERIZATION OF THE MAIZE POLLEN TRANSCRIPTOME

    Science.gov (United States)

    Pollen is a primary vehicle for transgene flow from engineered plants to their non-transgenic, native or weedy relatives. Hence, gene flow will be affected by pollen fitness (e.g., how well a particular pollen grain can outcompete other pollen present on the stigma and complete ...

  6. Pollen germination and pollen tube growth in ZP maize lines

    Directory of Open Access Journals (Sweden)

    Cerović Radosav

    2014-01-01

    Full Text Available The study was conducted on the in vitro pollen germination at 26°, 28°, 32° and 35°C for 24h of male parental lines, pollen tube growth in vivo in cross pollination of female and male parental lines that make couples in four hybrids: ZP 504 su (♀ ZPPL 51 × ♂ ZPPL 67; ZP 677 (♀ ZPPL 17 × ♂ ZPPL 201; ZP 704 (♀ ZPPL 109 × ♂ ZPPL 79, ZP 611 k (♀ ZPPL 126 × ♂ ZPPL 105, and the open pollination of female parental lines of the above mentioned hybrids. Pollen germination in vitro and pollen tube growth dynamics in vivo showed different genotypic specificities with the tests applied. The obtained results were discussed in the context of reproductive biology of ZP maize lines and aimed to create the preconditions for successful management and direction of the process in practice - seed production in certain environmental conditions.

  7. Evolutionary dynamics of birch (Betula aetnensis Rafin coppices on the Mount Etna (Sicily

    Directory of Open Access Journals (Sweden)

    Bagnato S

    2014-04-01

    Full Text Available Evolutionary dynamics of birch (Betula aetnensis Rafin coppices on the Mount Etna (Sicily. The aim of this paper is to evaluate the dynamics of Etna birch stands (Betula aetnensis Rafin following the cessation of silvicultural activities in the Etna Regional Park (Sicily. We investigated forest structure, natural regeneration, vegetation and deadwood in different forest types. Our findings highlighted three different dynamics for birch populations: stable birch stands in the high mountain area which might represent an edapho-climax forest; progressive dynamic birch stands in the intermediate mountain area, showing a gradual depletion of birch and a concomitant replacement with monospecific stands (calabrian pine, beech, oaks or mixed ones (with birch; pure birch stands (typical that tend to be regressive - especially under stressful conditions - and to be replaced by xerophilous grasslands. Following the cessation of coppicing and with stand ageing, the stumps transformation into more homogeneous stand structures have been increasing. Within the context of protected areas the restoration of coppice selection system (with appropriate adaptations could help to maintain the traditional forest landscape, acting as a silvicultural technique with low environmental and landscape impact.

  8. Sensitization rates of airborne pollen and mold in children

    Directory of Open Access Journals (Sweden)

    So Hyun Park

    2012-09-01

    Full Text Available &lt;B&gt;Purpose:&lt;/b&gt; Aeroallergens are important causative factors of allergic diseases. Previous studies on aeroallergen sensitization rates investigated patients groups that had visited pediatric allergy clinics. In contrast, we investigated sensitization rates in a general population group of elementary school to teenage students in Incheon, Jeju, and Ulsan. &lt;b&gt;Methods:&lt;/B&gt; After obtaining parental consent, skin-prick tests were performed on 5,094 students between March and June 2010. Elementary school students were tested for 18 common aeroallergens, whereas middle and high school students were tested for 25 allergens. The 25 allergens included &lt;I&gt;Dermatophagoides pteronyssinus, Dermatophagoides farinae&lt;/I&gt;, pollen (birch, alder, oak, Japanese cedar, pine, willow, elm, maple, Bermuda grass, timothy grass, rye grass, orchard grass, meadow grass, vernal grass, mugwort, Japanese hop, fat hen, ragweed, and plantain, and mold (&lt;I&gt;Penicillatum, Aspergillus, Cladosporium, and Alternaria&lt;/I&gt;. &lt;b&gt;Results:&lt;/b&gt; The sensitization rates in descending order were 25.79% (&lt;I&gt;D. pteronyssinus&lt;/I&gt; , 18.66% (&lt;I&gt;D. farinae&lt;/I&gt; , 6.20% (mugwort, and 4.07% (willow in Incheon; 33.35% (&lt;I&gt;D. pteronyssinus&lt;/I&gt; , 24.78% (&lt;I&gt;D. farinae&lt;/I&gt;, 15.36% (Japanese cedar, and 7.33% (Alternaria in Jeju; and 32.79% (D. pteronyssinus, 30.27% (D. farinae, 10.13% (alder, and 8.68% (birch in Ulsan. The dust mite allergen showed the highest sensitization rate among the 3 regions. The sensitization rate of tree pollen was the highest in Ulsan, whereas that of Alternaria was the highest in Jeju. The ragweed sensitization rates were 0.99% in Incheon, 1.07% in Jeju, and 0.81% in Ulsan. &lt;b&gt;Conclusion:&lt;/b&gt; The

  9. Effect of gamma rays doses on pollen germination, polysiphony and pollen tube elongation in Pinus patula Schiede et Deppe

    International Nuclear Information System (INIS)

    Katiyar, S.R.; Chauhan, Y.S.

    1987-01-01

    The present study aimed to study the effects of gamma radiation ( 60 Co) on pollen germination and pollen tube elongation in Pinus patula. Pollen germination and pollen tube elongation are stimulated by low doses of radiation. Although higher doses of radiation inhibit the germination of pollen, pollen tube elongation remains unaffected. Thus in Pinus patula pollen tube elongation is less radiosensitive than pollen germination. Compared to control pollen, irradiated pollen produced more number of long pollen tubes. Therefore pollen tube size can be improved using low doses of radiation. (author). 15 refs., 5 figs., 2 tables

  10. Geochemistry of the Birch Creek Drainage Basin, Idaho

    Science.gov (United States)

    Swanson, Shawn A.; Rosentreter, Jeffrey J.; Bartholomay, Roy C.; Knobel, LeRoy L.

    2003-01-01

    The U.S. Survey and Idaho State University, in cooperation with the U.S. Department of Energy, are conducting studies to describe the chemical character of ground water that moves as underflow from drainage basins into the eastern Snake River Plain aquifer (ESRPA) system at and near the Idaho National Engineering and Environmental Laboratory (INEEL) and the effects of these recharge waters on the geochemistry of the ESRPA system. Each of these recharge waters has a hydrochemical character related to geochemical processes, especially water-rock interactions, that occur during migration to the ESRPA. Results of these studies will benefit ongoing and planned geochemical modeling of the ESRPA at the INEEL by providing model input on the hydrochemical character of water from each drainage basin. During 2000, water samples were collected from five wells and one surface-water site in the Birch Creek drainage basin and analyzed for selected inorganic constituents, nutrients, dissolved organic carbon, tritium, measurements of gross alpha and beta radioactivity, and stable isotopes. Four duplicate samples also were collected for quality assurance. Results, which include analyses of samples previously collected from four other sites, in the basin, show that most water from the Birch Creek drainage basin has a calcium-magnesium bicarbonate character. The Birch Creek Valley can be divided roughly into three hydrologic areas. In the northern part, ground water is forced to the surface by a basalt barrier and the sampling sites were either surface water or shallow wells. Water chemistry in this area was characterized by simple evaporation models, simple calcite-carbon dioxide models, or complex models involving carbonate and silicate minerals. The central part of the valley is filled by sedimentary material and the sampling sites were wells that are deeper than those in the northern part. Water chemistry in this area was characterized by simple calcite-dolomite-carbon dioxide

  11. Pollen counts in the television media.

    Science.gov (United States)

    Giberson, J E; Murray, L W; Frenz, D A

    1997-01-01

    Allergists routinely supply pollen counts to television stations to assist allergy sufferers and to publicize their medical practices. This investigation examined how widely pollen counts are used in television news programming. The authors telephoned the news director or a meteorologist at 121 broadcast television stations in the nation's 30 largest Designated Market Areas (DMAs). They were asked if pollen counts were included or would be included in news programming during the 1995 pollen season. At least one television station in 28 DMAs included pollen counts in news programming. All five stations in the Washington, DC, DMA aired pollen counts; however, no stations in the Pittsburgh or Milwaukee DMAs carried pollen information. Approximately 49 million television households have access to pollen counts through a broadcast television station. Because these data appear important to television stations and to the public, the authors outline four measures to assure the reliability and meaningfulness of pollen information.

  12. Pollen analyses for pollination research, acetolysis

    Directory of Open Access Journals (Sweden)

    Gretchen D. Jones

    2014-08-01

    Full Text Available Analysis of the pollen associated with pollinators can reveal their role in pollination, the habitats and plants they visit, from where they migrated, what they eat, and dispersal patterns in and around cropping systems. However, finding pollen on and or in a pollinator depends on the technique used to recover the pollen. Acetolysis can be used to recover pollen from internal insect tissues (gut, alimentary canal, crop, etc., external tissues (proboscis, legs, eyes, etc. or both. Acetolysis is the best technique for recovering pollen because any tissue is dissolved and lipids and debris are removed from the sample and the pollen grains. This makes the diagnostic characteristics of the pollen grains more visible so that accurate pollen identification can be made. By using the proper technique, better pollen recovery can be made and thus better data can be obtained.

  13. Pollen Forecast and Dispersion Modelling

    Science.gov (United States)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  14. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    Science.gov (United States)

    Vogler, Frank; Konrad, Sebastian S. A.; Sprunck, Stefanie

    2015-01-01

    Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane. PMID:25954283

  15. Coconut (Cocos nucifera l.) pollen cryopreservation.

    Science.gov (United States)

    Karun, A; Sjini, K K; Niral, V; Amarnth, C H; Remya, P; Rajesh, M K; Samsudeen, K; Jerard, B A; Engelmann, F

    2014-01-01

    Coconut genetic resources are threatened by pests and pathogens, natural hazards and human activities. Cryopreservation is the only method allowing the safe and cost-effective long-term conservation of recalcitrant seed species such as coconut. The objective of this work was to test the effect of cryopreservation and of cryostorage duration on coconut pollen germination and fertility. Pollen of two coconut varieties (West Coast Tall WWCTW and Chowghat Orange Dwarf CODC) was collected in March-May over three successive years, desiccated to 7.5 % moisture content (FW) and cryopreserved by direct immersion in liquid nitrogen. Germination and pollen tube length (PTL) of desiccated and cryopreserved pollen were not significantly different for both WCT and COD over the three harvest months of the three consecutive years of study. Pollen germination ranged from 24 to 32 % in desiccated pollen whereas it was between 26 and 29 % in cryopreserved COD pollen. In the case of WCT, germination ranged from 30 to 31 % in desiccated pollen, while it was between 28 and 32 % in cryopreserved pollen. PTL of cryopreserved pollen ranged between 224-390 nm and 226-396 mm for COD and WCT, respectively. Germination of COD pollen varied between 29.0 and 44.1 % after 4 years and 1.0/1.5 years cryostorage, respectively. Germination of WCT pollen did not change significantly between 0 and 6 years cryostorage, being comprised between 32 (24 h) and 40 % (1.5 years). Germination and vigour of cryopreserved pollen were generally higher compared to that of pollen dried in oven and non-cryopreserved. Normal seed set was observed in COD and WCT palms using pollen cryostored for 6 months and 4 years. Cryopreserved pollen of five Tall and five Dwarf accessions displayed 24-31 % and 25-49 % germination, respectively. These results show that it is now possible to establish pollen cryobanks to contribute to coconut germplasm long-term conservation.

  16. Pollen morphology and viability in Bromeliaceae

    Directory of Open Access Journals (Sweden)

    EVERTON H. SOUZA

    2017-12-01

    Full Text Available ABSTRACT Pollen morphology characterization is important in taxonomy, conservation and plant breeding, and pollen viability studies can support breeding programs. This study investigated pollen morphology and male fertility in 18 species of Bromeliaceae with ornamental potential. For morphological characterization, pollen grains were acetolyzed and characterization of exine was done using scanning and transmission electron microscopy. Pollen viability was investigated by in vitro germination and histochemical tests. Species belonging to Aechmea and Ananas genera presented medium size pollen, except for Ae. fasciata, with large pollen. Al. nahoumii, P. sagenarius and the Vriesea species analyzed showed large pollen, except for V. carinata, with very large pollen. Pollen of Aechmea, Ananas and P. sagenarius presented bilateral symmetry, diporate, exine varying from tectate to semitectate. Al. nahoumii and Vriesea species presented pollen with bilateral symmetry, monocolpate; exine was semitectate, reticulate and heterobrochate. Germination percentage and tube growth were greater in SM and BKM media. Histochemical tests showed pollen viability above 70% for all species, except for Ananas sp. (40%. Pollen morphology is important for the identification of species, especially in this family, which contains a large number of species. High rates of viability favor fertilization and seed production, essential for efficient hybrid production and conservation.

  17. Pollen morphology and viability in Bromeliaceae.

    Science.gov (United States)

    Souza, Everton H; Souza, Fernanda V D; Rossi, Mônica L; Packer, Renan M; Cruz-Barros, Maria Amelia V; Martinelli, Adriana P

    2017-01-01

    Pollen morphology characterization is important in taxonomy, conservation and plant breeding, and pollen viability studies can support breeding programs. This study investigated pollen morphology and male fertility in 18 species of Bromeliaceae with ornamental potential. For morphological characterization, pollen grains were acetolyzed and characterization of exine was done using scanning and transmission electron microscopy. Pollen viability was investigated by in vitro germination and histochemical tests. Species belonging to Aechmea and Ananas genera presented medium size pollen, except for Ae. fasciata, with large pollen. Al. nahoumii, P. sagenarius and the Vriesea species analyzed showed large pollen, except for V. carinata, with very large pollen. Pollen of Aechmea, Ananas and P. sagenarius presented bilateral symmetry, diporate, exine varying from tectate to semitectate. Al. nahoumii and Vriesea species presented pollen with bilateral symmetry, monocolpate; exine was semitectate, reticulate and heterobrochate. Germination percentage and tube growth were greater in SM and BKM media. Histochemical tests showed pollen viability above 70% for all species, except for Ananas sp. (40%). Pollen morphology is important for the identification of species, especially in this family, which contains a large number of species. High rates of viability favor fertilization and seed production, essential for efficient hybrid production and conservation.

  18. National Allergy Bureau Pollen and Mold Report

    Science.gov (United States)

    ... Search AAAAI National Allergy Bureau Pollen and Mold Report Date: May 01, 2018 Location: San Antonio (2), ... 30/2018 ( click here to view ). Our Allergen Report Email Service can automatically email you daily pollen ...

  19. Effect of birch (Betula spp.) and associated rhizoidal bacteria on the degradation of soil polyaromatic hydrocarbons, PAH-induced changes in birch proteome and bacterial community

    Energy Technology Data Exchange (ETDEWEB)

    Tervahauta, Arja I. [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland)], E-mail: arja.tervahauta@uku.fi; Fortelius, Carola [EVTEK University of Applied Sciences, Vantaa (Finland); Tuomainen, Marjo [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland); Akerman, Marja-Leena [EVTEK University of Applied Sciences, Vantaa (Finland); Rantalainen, Kimmo [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland); Sipilae, Timo [Department of Biological and Environmental Sciences, University of Helsinki (Finland); Lehesranta, Satu J.; Koistinen, Kaisa M.; Kaerenlampi, Sirpa [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland); Yrjaelae, Kim [Department of Biological and Environmental Sciences, University of Helsinki (Finland)

    2009-01-15

    Two birch clones originating from metal-contaminated sites were exposed for 3 months to soils (sand-peat ratio 1:1 or 4:1) spiked with a mixture of polyaromatic hydrocarbons (PAHs; anthracene, fluoranthene, phenanthrene, pyrene). PAH degradation differed between the two birch clones and also by the soil type. The statistically most significant elimination (p {<=} 0.01), i.e. 88% of total PAHs, was observed in the more sandy soil planted with birch, the clearest positive effect being found with Betula pubescens clone on phenanthrene. PAHs and soil composition had rather small effects on birch protein complement. Three proteins with clonal differences were identified: ferritin-like protein, auxin-induced protein and peroxidase. Differences in planted and non-planted soils were detected in bacterial communities by 16S rRNA T-RFLP, and the overall bacterial community structures were diverse. Even though both represent complex systems, trees and rhizoidal microbes in combination can provide interesting possibilities for bioremediation of PAH-polluted soils. - Birch can enhance degradation of PAH compounds in the rhizosphere.

  20. Pollen loads of eucalypt and other pollen types in birds in NW Spain

    Directory of Open Access Journals (Sweden)

    María Calviño-Cancela

    2015-12-01

    Full Text Available Here we present the amount of pollen of eucalypt and pollen of other types for birds captured in two bird ringing stations for 14 months (March 2014 to April 2015 in NW Spain. Common and latin names of all birds species captured, together with the number of captured individuals (N, prevalence of eucalypt pollen (percentage of individuals with eucalypt pollen and of pollen of other types and average pollen loads per individual for eucalypt and other pollen types is presented. See [1] for further information and discussion.

  1. [The epidemiology of pollen allergy].

    Science.gov (United States)

    Charpin, D; Caillaud, D

    2014-04-01

    The prevalence of seasonal allergic rhinitis can be established through surveys performed in a sample of the general population. These surveys are based on a questionnaire, which could lead to an overestimate of prevalence rates, and on measurements of specific IgE, which need to be interpreted in the light of the responses to the questionnaire. Such surveys are few in France and need to be updated. Risk factors for seasonal allergic rhinitis are genetic, epigenetic and environmental. Relationships between exposure to pollen and health can be documented through ecological and panel surveys. Panel surveys may give information on threshold levels and dose-response relationships. In addition to pollen exposure, global warming and air pollutants act as cofactors. Monitoring of both pollen exposure and its health effects should be encouraged and strengthened. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  2. Seasonal dynamics of chemokine receptors and CD62L in subjects with asymptomatic skin sensitization to birch and grass pollen

    DEFF Research Database (Denmark)

    Assing, K; Bodtger, U; Poulsen, Lars K.

    2006-01-01

    Asymptomatic skin sensitization (AS) has been shown to be a risk factor for respiratory allergic disease. CCR4, CXCR1 and CD62L have all been assigned a role in the immunopathogenesis of allergy. Memory T-cell expression of CCR4, CXCR1 and CD62L has not hitherto been investigated in subjects...

  3. Strain-specific immunomodulatory effects of Lactobacillus plantarum strains on birch-pollen-allergic subjects out of season

    NARCIS (Netherlands)

    Snel, J.; Vissers, Y.M.; Smit, B.A.; Jongen, J.M.J.; Meulen, E.T.; Zwijsen, R.

    2011-01-01

    Background Allergic diseases are increasing world-wide, and according to the hygiene hypothesis may be related to a decreased exposure to environmental bacteria. Probiotic bacteria are recognized for their immunomodulating properties, and may benefit allergy patients. In vitro studies reveal

  4. Evidence of pollen tubes in paleozoic pteridosperms.

    Science.gov (United States)

    Rothwell, G W

    1972-02-18

    A saccate pollen grain with a branched pollen tube has been discovered within the pollen chamber of a fossil seed-fern ovule of Middle Pennsylvanian age. This suggests that microgametophytes comparable to those of living gymnosperms were produced by some Paleozoic pteridosperms.

  5. Pollen characteristics and in vitro pollen germination of Cedrus ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... 1Forest Tree Seeds and Tree Breeding Research Directory, Ankara, Turkey. 2Zonguldak Karaelmas ... germination rate in MS medium was achieved in clone no.11342 with 84.77% among the pollen samples of 2005. On the other hand ... Among these species, Cedrus libani A. Rich. (Lebanon. Cedar) is a ...

  6. Performance of moth larvae on birch in relation to altitude, climate, host quality and parasitoids

    OpenAIRE

    Virtanen, T.; Neuvonen, S.

    1999-01-01

    Abstract We studied topographical and year-to-year variation in the performance (pupal weights, survival) and larval parasitism of Epirrita autumnata larvae feeding on mountain birch in northernmost Finland in 1993-1996. We found differences in both food plant quality and parasitism between sites ranging from 80 m to 320 m above sea level. Variation in food plant quality had particularly marked effects on larval survival. The advanced phenology of the birches in relation to the start of the l...

  7. Study on the Modification of Bleached Eucalyptus Kraft Pulp Using Birch Xylan

    Science.gov (United States)

    Wenjia Han; Chuanshan Zhao; Thomas Elder; Rendang Yang; Dongho Kim; Yunqiao Pu; Jeffery Hsieh; Arthur J. Ragauskas

    2012-01-01

    In this study, birch xylan was deposited onto elementally chlorine free (ECF) bleached eucalyptus kraft pulp, and the corresponding changes in physical properties were determined. An aqueous 5% birch xylan solution at pH 9 was added to 5 wt% slurry of bleached kraft eucalyptus fibers, with stirring at 70 C for 15 min after which the pH was adjusted to 5–6. The xylan...

  8. A Stratigraphic Pollen Record from a Late Pleistocene Cypress Forest, Northern Gulf of Mexico Continental Shelf

    Science.gov (United States)

    Reese, A.; Harley, G. L.; DeLong, K. L.; Bentley, S. J.; Xu, K.; Gonzalez Rodriguez, S. M.; Truong, J. T.; Obelcz, J.; Caporaso, A.

    2017-12-01

    Stratigraphic pollen analysis was performed on a layer of preserved peat found near the bottom of a 4.75m vibracore taken in 18m of water off the coast of Orange Beach, Alabama. The core was taken from a site where the remains of a previously buried bald cypress (Taxodium distichum) forest was discovered after wave action, likely from Hurricane Ivan in 2004, scoured and removed the overlying Holocene/late Pleistocene sand sheet. Many of the cypress stumps found at the site are still in growth position, and rooted in the preserved terrestrial soils below. Radiocarbon dating of the peat recovered in core DF1 suggests that the sediment is likely Marine Isotope Stage 3 (MIS 3), or earlier. We hypothesize that the site was quickly buried and preserved by floodplain aggradation associated with sea-level rise that occurred near the end of MIS 3. This rare find provides an opportunity to study in situ fossil pollen from a glacial refugium in the Northern Gulf of Mexico. Pollen results from the lowermost sections within the peat layer show an assemblage consistent with a bald cypress/tupelo gum (Nyssa aquatica) backwater. This is eventually replaced by a more open, possibly brackish, environment, dominated by grasses (Poaceae) and sedges (Cyperaceae). During this change however, there is a brief but very interesting period where the pollen assemblage is likely analogous to the modern day Atlantic Coastal Plain Blackwater Levee/Bar Forests of North and South Carolina. In this modern assemblage, as well as the core samples, birch (Betula), oak (Quercus) and bald cypress are the dominant taxa, along with a strong presence of alder (Alnus), grasses and sedges. We hypothesize that these bar forests formed on areas of higher ground, which resulted from floodplain aggradation that accompanied sea level rise at the end of MIS 3.

  9. Vegetation of birch and aspen forests in the Pinega State Reserve

    Directory of Open Access Journals (Sweden)

    Sergey Yu. Popov

    2017-05-01

    Full Text Available The Pinega State Nature Reserve (Russia is located in the Arkhangelsk region in the northern taiga subzone. Together with spruce forests and mires, birch forests represent one of the most wide-spread plant communities of its territory. Birch forests cover 24.6% of the Reserve's area. Aspen forests are rare plant communities in the Pinega Reserve. These forests cover only 0.9% of the whole Reserve's area. The birch and aspen forests vegetation has been classified based on 82 relevès. Eleven associations could be distinguished, which represent six groups of associations. Detailed characteristics of these syntaxa are provided including their biodiversity analysis. The analysis allowed establishing that the revealed syntaxa differ in relation to habitat environmental conditions: e.g., soil moisture, trophicity, nitrogen saturation and soil acidity. Sphagnum and blueberry birch forests proved to be the poorest in nitrogen, in contrast to the richest humidoherbaceous and broad-grassed groups of birch forest associations. Broad-grassed birch forests in the Pinega Reserve inhabit the most drained locations, while humidoherbaceous and Sphagnum forests occur in lesser drained locations.

  10. Proteomics of pollen development and germination.

    Science.gov (United States)

    Dai, Shaojun; Wang, Tai; Yan, Xiufeng; Chen, Sixue

    2007-12-01

    In higher plants, pollen grains represent the vestiges of a highly reduced male gametophyte generation. After germination, the pollen tube delivers the sperm cells by tip-growing to the embryo sac for fertilization. Besides the intrinsic importance for sexual reproduction, pollen development and germination serve as an attractive system to address important questions related to cell division, cell differentiation, polar growth, cell-cell interaction, and cell fate. Recently, pollen functional specification has been well-studied using multidisciplinary approaches. Here, we review recent advances in proteomics of pollen development and germination.

  11. A Simple, Inexpensive Pollen Trap

    Science.gov (United States)

    P. E. Hoekstra

    1965-01-01

    Pollen plays a role of vital importance in the sexual reproduction of all plants but it is especially important in forestry. With few exceptions, sexual reproduction is the only link between succeeding generations in the forest. To be sure, vegetative reproduction is important for special purposes, but it will probably not be used on a mass scale in timber...

  12. Comparative Pollen Development in Dioscoreales

    NARCIS (Netherlands)

    Schols, P.; Furness, C.; Merckx, V.; Wilkin, P.; Smets, E.

    2005-01-01

    Pollen and orbicule ontogeny in representatives of three genera of Dioscoreales—Narthecium ossifragum Huds. (Nartheciaceae), Tacca artocarpifolia Seem. and Tacca chantrieri Andre´ (Dioscoreaceae), and Dioscorea communis (L.) Caddick & Wilkin (Dioscoreaceae)—is described and illustrated using LM,

  13. Pollen grains are efficient cloud condensation nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pope, F D, E-mail: fdp21@cam.ac.uk [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2010-10-15

    This letter presents a laboratory study investigating the ability of pollen grains to act as cloud condensation nuclei. The hygroscopicity of pollen is measured under subsaturated relative humidities using an electrodynamic balance. It is found, along with other results, that pollen exhibits bulk uptake of water under subsaturated conditions. Through the use of an environmental scanning electron microscope it was observed that the surface of pollen is wettable at high subsaturated humidities. The hygroscopic response of the pollen to subsaturated relative humidities is parametrized using {kappa}-Koehler theory and values of the parameter {kappa} for pollen are between 0.05 and 0.1. It is found that while pollen grains are only moderately hygroscopic, they can activate at critical supersaturations of 0.001% and lower, and thus pollen grains will readily act as cloud condensation nuclei. While the number density of pollen grains is too low for them to represent a significant global source of cloud condensation nuclei, the large sizes of pollen grains suggest that they will be an important source of giant cloud condensation nuclei. Low temperature work using the environmental scanning electron microscope indicated that pollen grains do not act as deposition ice nuclei at temperatures warmer than - 15 deg. C.

  14. Taraxacum officinale pollen depresses seed set of montane wildflowers through pollen allelopathy

    Directory of Open Access Journals (Sweden)

    Deirdre Loughnan

    2014-08-01

    Full Text Available Plant species that share pollinators can suffer from interspecific pollen deposition. Male reproductive success is inevitably reduced by the loss of pollen to flowers of another species. Female reproductive success can be affected by reduced stigmatic area or, more strongly, through allelopathic effects by which the admixture of some foreign pollen reduces seed or fruit set. We tested for allelopathic effects of Taraxacum officinale (Asteracaeae pollen on the seed set of montane wildflowers Erythronium grandiflorum (Liliaceae and Erysimum capitatum (Brassicaceae, by hand-pollinating plants with pollen mixtures. Taraxacum is a common invasive species, which produces allelopathic chemicals in its root and vegetative tissue, making it a likely candidate for pollen allelopathy. Flowers of both species produced fewer well-developed seeds when pollinated with pollen mixtures containing Taraxacum pollen. The pollen-allelopathic potential of weedy dandelion may add to its ability to disrupt communities that it invades.

  15. Pollen selection under acid rain stress

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.

    1994-01-01

    To investigate whether acid rain stress induces pollen selection in nature, three different approaches were used, based on the assumption that the response of pollen grains to acid rain is controlled by an acid sensitive gene product. Germination of pollen from homozygous and heterozygous individuals under acid rain stress was examined to detect any differences in rate of germination between populations of homogeneous and heterogeneous pollen grains. In vitro and in vivo bulked segregant analysis using RAPDs was used to search for differences in DNA constitution between the survivors of acid rain stressed and non-acid rain stressed pollen populations in vitro and between the progenies of acid rain stressed and non-acid rain stressed populations during pollination, respectively. No evidence for the pollen selection under acid rain stress was obtained in any of the test systems. Inhibition of protein synthesis using cycloheximide led to significant reduction of tube elongation at 4 hr and had no effect on pollen germination at any time interval tested. Total proteins extracted from control and acid rain stressed pollen grain populations exhibited no differences. The reduction of corn pollen germination in vitro under acid rain stress was mainly due to pollen rupture. The present data indicates the reduction of pollen germination and tube growth under acid rain stress may be a physiological response rather than a genetic response. A simple, nontoxic, and effective method to separate germinated from ungerminated pollen grains has been developed using pollen from corn (Zea mays, L. cv. Pioneer 3747). The separated germinated pollen grains retained viability and continued tube growth when placed in culture medium.

  16. BASALIT trial: double-blind placebo-controlled allergen immunotherapy with rBet v 1-FV in birch-related soya allergy.

    Science.gov (United States)

    Treudler, R; Franke, A; Schmiedeknecht, A; Ballmer-Weber, B; Worm, M; Werfel, T; Jappe, U; Biedermann, T; Schmitt, J; Brehler, R; Kleinheinz, A; Kleine-Tebbe, J; Brüning, H; Ruëff, F; Ring, J; Saloga, J; Schäkel, K; Holzhauser, T; Vieths, S; Simon, J C

    2017-08-01

    Conflicting results exist on the effect of allergen immunotherapy (AIT) on pollen-related food allergy. We aimed to investigate the efficacy of one-year AIT with the folding variant (FV) of recombinant (r) Bet v 1 on birch-related soya allergy. Of 138 subjects with Bet v 1 sensitization, 82 were positive at double-blind placebo-controlled food challenge (DBPCFC) with soya. A total of 56 of 82 were randomized in the ratio of 2:1 (active: placebo). Per-protocol population (PPP) had received ≥150 μg of allergen or placebo preparation. lowest observed adverse effect levels (LOAEL), postinterventional occurrence of objective signs (objS) at any dose level, sIgE/IgG4 against Bet v 1 and Gly m 4. Between-group changes were investigated (ancova, Mann-Whitney U-test, Fisher exact test). Baseline characteristics including LOAELs were comparable in both groups with objS and subjS occurring in 82% and 95% of active (n = 38) vs 78% and 83% of placebo group (n = 18). After AIT, objS occurred in 24% and 47%, respectively. LOAEL group differences showed a beneficial tendency (P = 0.081) for LOAEL objective in PPP (30 active, 15 placebo). sIgG4 raised only in active group (Bet v 1: P = 0.054, Gly m 4: P = 0.037), and no relevant changes occurred for sIgE. Only 56% of the intended sample size was recruited. For the first time, we present data on the effect of rBet v 1-FV on birch-related soya allergy. rBet v 1-FV AIT induced significant immunogenic effects. Clinical assessment showed a tendency in favour of the active group but did not reach statistical significance. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Damping properties of sequoia and birch under shock loading

    International Nuclear Information System (INIS)

    Bolshakov, A.P.; Gerdjukov, N.N.; Zotov, E.V.; Novikov, S.A.; Sinitsin, V.A.; Scherbak, Y.I.

    1998-01-01

    The decrease mechanic effect on loads being transported, shock load limiters (dampers) are being widely used today. Usually, the materials having 'stress-strain' diagrams (σ-ε) of compression with a substantial portion, where σ = const., are used as dampers. Most widely used are dampers made of foam polystyrene having just the same compression diagram. Similar strain diagrams can be enlisted for some porous materials, timber under cross compression, perforated metallic crushers and some others. By selecting damper material, the level of transmitted to the protected object pressures can be varied from several to hundreds MPa. Timber, as being widely used and featuring good technologic properties together with low cost, becomes an attractive material to be used as the limiter of shock loads. This paper presents the results of stress-strain sequoia properties (USA deliverable) and birch properties (Volgo-Vyatski region) at dynamic (v = 10 m/s) and quasistatic (v ≅ 10 -4 m/s) loading rates. The samples (diameter 25 x 25 mm) cut at 0, 5, 10, 15, 30, 45 and 90 deg. angle relative to their fibre were tested on one-axis compression at -30, +20 and +65 deg. C and fixed humidity (ω = 6-7%). Dynamic tests employed Kolsky method performed at the facility including Hopkinson's compound rod (Zukas et al.,1985). Sample loading was executed by trapezoidal pulsed pressure created by the explosive device. Samples were heated and cooled by special thermostats. (authors)

  18. The impact of birch seedlings on evapotranspiration from a mined peatland: an experimental study in southern Quebec, Canada

    Directory of Open Access Journals (Sweden)

    E. Fay

    2009-03-01

    Full Text Available Dense stands of birch (Betula spp. on abandoned peat workings have often been identified as potential barriers to site restoration, but little research has been conducted to evaluate their impact on water resources. The objective of this experimental study was to determine whether birch seedlings established on an abandoned mined peatland in eastern Canada had a significant impact on evapotranspiration. Transpiration rates from birch seedlings planted in containers filled with Sphagnum compost were measured gravimetrically. Unplanted containers were used to similarly measure evaporation rates from bare peat. On average, the measured rates of evaporation (per unit area from peat were 2.5 times the rates of transpiration from birch leaves. However, if the total leaf area of a dense birch population established on an abandoned mined peatland is considered, the total amount of water lost through birch transpiration could be higher than that lost by evaporation from the peat surface. This study provides a rough estimate of potential water losses due to birch seedling transpiration, and indicates that a dense population of birch on a mined peatland may influence site hydrology even at the early establishment phase (seedlings. Consequently, recently abandoned mined peatlands should be restored rapidly to prevent the establishment of birch trees.

  19. Ecological and phytopathological status of birch stands on the territory of Krasnoyarsk group of districts

    Directory of Open Access Journals (Sweden)

    A. I. Tatarintsev

    2015-04-01

    Full Text Available According to inspection data, the health and vital status of birch (Betula pendula Roth. stands in Krasnoyarsk group of lands (southern part of Central Siberia were estimated (established as satisfactory in general; about half of birch stands near urbanized areas were weakened. The condition of stands decreased significantly with increased recreation use, the effect of technogenic pollution was negligible. The most valuable (important representatives of pathogenic biota identified on birch trees were infestations of necrotic cancer and rot diseases. In birch stands the bacterial dropsy was found to be widespread (agent of infection – Erwinia multivora Scz.-Parf, occurrence of the disease ranged from a single ill tree up to 10–38 % of the stands. The birch stands in taiga areas were affected to a greater extent than in forest-steppe; there were high yield class stands on moist soils. Prevalence of bacteriosis rose with increasing stand age and density and not dependent on recreation use level. Trees with dropsy are dead in fact or potentially. In taiga birch forests the infection and rot of roots was caused by honey agaric (Armillaria mellea sensu lato, that lead to single or, rarely, group tree drying and the fungus usually eliminated already weakened trees. Wood biomass was destroyed by complex of aphyllophorous Hymenomycetes, their hemiparasitic species caused stem rots that decreased stand marketability and also resulted in rot-realated wind-break accumulation. Occurrence of rot was significantly higher in second growth birch stands, possibly above 20 %; the relationship between rot prevalence and forest assessment was not revealed.

  20. Pollen development in Annona cherimola Mill. (Annonaceae. Implications for the evolution of aggregated pollen

    Directory of Open Access Journals (Sweden)

    Hormaza Jose I

    2009-10-01

    Full Text Available Abstract Background In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Results Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Conclusion Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer.

  1. Pollen development in Annona cherimola Mill. (Annonaceae). Implications for the evolution of aggregated pollen

    Science.gov (United States)

    Lora, Jorge; Testillano, Pilar S; Risueño, Maria C; Hormaza, Jose I; Herrero, Maria

    2009-01-01

    Background In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Results Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Conclusion Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer. PMID:19874617

  2. The long pollen tube journey and in vitro pollen germination of Phalaenopsis orchids.

    Science.gov (United States)

    Chen, Jhun-Chen; Fang, Su-Chiung

    2016-06-01

    Pollen biology in P. aphrodite. Orchids have a distinct reproductive program. Pollination triggers ovule development and differentiation within flowers, and fertilization occurs days to months after pollination. It is unclear how pollen tubes travel through the developing ovaries during ovule development and when pollen tubes arrive at the mature embryo sac to achieve fertilization. Here, we report a robust staining protocol to image and record the timing of pollen germination, progressive growth of pollen tubes in ovaries, and arrival of pollen tubes at embryo sacs in Phalaenopsis aphrodite. The pollen germinated and pollen tubes entered the ovary 3 days after pollination. Pollen tubes continued to grow and filled the entire cavity of the ovary as the ovary elongated and ovules developed. Pollen tubes were found to enter the matured embryo sacs at approximately 60-65 days after pollination in an acropetal manner. Moreover, these temporal changes in developmental events such as growth of pollen tubes and fertilization were associated with expression of molecular markers. In addition, we developed an in vitro pollen germination protocol, which is valuable to enable studies on pollen tube guidance and tip growth regulation in Phalaenopsis orchids and possibly in other orchid species.

  3. Pollen parameters estimates of genetic variability among newly ...

    African Journals Online (AJOL)

    Estimates of some pollen parameters where used to assess the genetic diversity among some newly selected Nigerian Roselle (Hibiscus sabdariffa L.). Standard procedures were used to determine the pollen parameters such as: percentage pollen fertility, percentage pollen sterility, pollen diameters as well as anther ...

  4. Potential health risk of allergenic pollen with climate change associated spreading capacity: Ragweed and olive sensitization in two German federal states.

    Science.gov (United States)

    Höflich, Conny; Balakirski, Galina; Hajdu, Zuzanna; Baron, Jens Malte; Kaiser, Lorraine; Czaja, Katharina; Merk, Hans F; Gerdsen, Sarah; Strassen, Ulrich; Bas, Murat; Bier, Henning; Dott, Wolfgang; Mücke, Hans-Guido; Straff, Wolfgang; Chaker, Adam; Röseler, Stefani

    2016-05-01

    Global climate changes may influence the geographical spread of allergenic plants thus causing new allergen challenges. Allergy patients from two German federal states were compared for their status quo sensitization to ragweed, an establishing allergen, olive, a non-established allergen, and the native allergens birch, mugwort, and ash. Between 2011 and 2013, 476 adult allergy patients per region were recruited. Patients completed a questionnaire, participated in a medical interview, and underwent skin prick testing and blood withdrawal for analysis of specific IgE to allergen components (ISAC technology). Data on regional pollen load from 2006 to 2011 were acquired from the German Pollen Information Service Foundation. Prick test reactivity to ragweed and ash, respectively, was lower in Bavaria than in NRW (ragweed: p=0.001, aOR=0.54; ash: p=0.001, aOR=0.59), whereas prick test reactivity to olive was higher (p=0.000, aOR=3.09). Prick test reactivity to birch and mugwort, respectively, did not significantly differ. 1% (1/127) of patients with prick test reactivity to ragweed showed sIgE to Amb a 1, and 65% (86/132) of olive-but-not-ash reactive patients showed sIgE to Ole e 1 (NRW: 67%, Bavaria: 65%; p=0.823, OR=0.91). Regional differences in sensitization pattern were neither explainable by cross-reactivity to pollen pan-allergens nor non-exposure variables nor by reported plant population or pollen data. Spread of ragweed and particularly olive may result in prompt occurrence of allergic symptoms. Early identification of invasive allergens due to climate change does need time and spatial close meshed measurement of respective indicator allergens and sensitization pattern. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  5. Pollen evidence for a mid-Holocene East Asian summer monsoon maximum in northern China

    Science.gov (United States)

    Wen, Ruilin; Xiao, Jule; Fan, Jiawei; Zhang, Shengrui; Yamagata, Hideki

    2017-11-01

    There is a controversy regarding whether the high precipitation delivered by an intensified East Asian summer monsoon occurred during the early Holocene, or during the middle Holocene, especially in the context of the monsoonal margin region. The conflicting views on the subject may be caused by chronological uncertainties and ambiguities in the interpretation of different climate proxies measured in different sedimentary sequences. Here, we present a detailed record of the Holocene evolution of vegetation in northern China based on a high-resolution pollen record from Dali Lake, located near the modern summer monsoon limit. From 12,000-8300 cal BP, the sandy land landscape changed from desert to open elm forest and shrubland, while dry steppe dominated the hilly lands and patches of birch forest developed in the mountains. Between 8300 and 6000 cal BP, elm forest was extensively distributed in the sandy lands, while typical steppe covered the hilly lands and mixed coniferous-broadleaved forests expanded in the mountains. Our pollen evidence contradicts the view that the monsoonal rainfall increased during the early Holocene; rather, it indicates that the East Asian summer monsoon did not become intensified until ∼8000 cal BP in northern China. The low precipitation during the early Holocene can be attributed to the boundary conditions, i.e., to the remnant high-latitude Northern Hemisphere ice sheets and the relatively low global sea level.

  6. [Effect of climatic changes on the phenology of plants and the presence of pollen in the air in Switzerland].

    Science.gov (United States)

    Schneiter, D; Bernard, B; Defila, C; Gehrig, R

    2002-04-01

    The phenologic observations carried out in Switzerland since 1951 show a clear tendency to the earlier appearance of the spring phases of development of the vegetation during last decades. As these phases are strongly influenced by the temperature, these results reinforce the hypothesis according to which the climatic reheating in progress strongly influences the development of the vegetation. The flowering and the release of the pollen of the plants allergens are significant phenologic phases for human health. Modifications in their dates of manifestation lead to a displacement of the periods of allergic risk. The analysis of the aerobiologic data of the Swiss stations over one duration of more than 20 years showed that the species which flower in winter and in spring were subject to the influence of the soft winters of the years 1990 to 2000. In certain areas the pollen of birch, for example, is nowadays waited on average 3 weeks earlier than 20 years ago, whereas the pollen of ash appears with one month in advance. The phenologic and aeropalynologic studies thus prove sensitive witnesses of the climatic change in progress. This last intervenes like an indirect but significant component of human health, in particular when the field of the allergies is considered.

  7. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Sharkey, Thomas D.; Calfapietra, Carlo; Karnosky, David F.

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO 2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO 2 protected photosynthesis of both species against moderate heat stress. Elevated CO 2 increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO 2 treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO 2 were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO 2 . Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO 2 confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  8. m-BIRCH: an online clustering approach for computer vision applications

    Science.gov (United States)

    Madan, Siddharth K.; Dana, Kristin J.

    2015-03-01

    We adapt a classic online clustering algorithm called Balanced Iterative Reducing and Clustering using Hierarchies (BIRCH), to incrementally cluster large datasets of features commonly used in multimedia and computer vision. We call the adapted version modified-BIRCH (m-BIRCH). The algorithm uses only a fraction of the dataset memory to perform clustering, and updates the clustering decisions when new data comes in. Modifications made in m-BIRCH enable data driven parameter selection and effectively handle varying density regions in the feature space. Data driven parameter selection automatically controls the level of coarseness of the data summarization. Effective handling of varying density regions is necessary to well represent the different density regions in data summarization. We use m-BIRCH to cluster 840K color SIFT descriptors, and 60K outlier corrupted grayscale patches. We use the algorithm to cluster datasets consisting of challenging non-convex clustering patterns. Our implementation of the algorithm provides an useful clustering tool and is made publicly available.

  9. The Puzzling Origin of the Acquaintance between Charlotte Lennox and Thomas Birch

    Directory of Open Access Journals (Sweden)

    Patricia L. Hamilton

    2015-03-01

    Full Text Available Scholars have puzzled over the origin of the relationship between Charlotte Lennox and Thomas Birch. That the two shared a cordial professional relationship in 1759 is not surprising, but it is unclear how and when Birch obtained the poem "The Dream, an ode by Miss Ramsey of 15" (ca. 1744-45 for his manuscript collection. Possibly Edward Cave, publisher of The Gentleman’s Magazine, or other professional associates such as Samuel Johnson or Samuel Richardson supplied it. But archival evidence indicates that Lady Isabella Finch, Lennox’s earliest patroness, was in contact with Birch in 1749, raising the question of whether she could have given Birch the poem. However, a different type of connection between Lennox and Birch is suggested by Lennox’s first novel, The Life of Harriot Stuart, written by Herself (1750, which mentions William Chillingworth, Isaac Barrow, and John Tillotson as theological influences. Lennox may have known of these three seventeenth-century divines through Birch’s biographical work on them.

  10. Birch mixture in spruce forest - a method to reduce the effects of acidification?

    International Nuclear Information System (INIS)

    Maartensson, Kristina.

    1996-01-01

    Acidification has lately been focus of increased attention in the business, industrial and public sectors. One measure that can prevent further acidification is the liming of forest soils. Another strategy would be to increase the admixture of deciduous tree species in conifer forest. This paper deals with the latter problem. From ecological and economical standpoints, the tree species offering the most advantageous admixture in Sweden would be birch, Betula pendula, and Norway spruce, Picea abies. Birch trees help to increase soil pH, while decreasing atmospheric deposition and protecting young spruce seedling from frost. The use of birch admixture need to be 50% or more to get required effect. This will lead to a reduction in spruce wood production. This need not to be a problem, however, since birch pulp will probably become more valuable in the future. The admixed forests have a higher biological diversity and are of greater value for recreation. Although spruce production on acidified sited is still high, further atmospheric deposition could lead to declines in production. Forest soils will eventually sustain serious damage if acid deposition continues to increase, which will require new alternatives for wood production be found. A high admixture of birch can offer a temporary respite if emission and deposition continue, but cannot completely compensate for the acidifying effects of present deposition levels. 26 refs, 2 figs

  11. The coexistence of bicellular and tricellular pollen in Annona cherimola (Annonaceae): Implications for pollen evolution

    OpenAIRE

    Lora, Jorge; Herrero Romero, María; Hormaza Urroz, José Ignacio

    2009-01-01

    Most angiosperms release bicellular pollen. However, in about one-third of extant angiosperms, the second pollen mitosis occurs before anthesis such that pollen is tricellular upon release. The shift from bicellular to tricellular development has occurred several times independently, but its causes are largely unknown. In this work, we observed the coexistence of both kinds of pollen at anther dehiscence in Annona cherimola, a species that belongs to the basal angiosperm family Annonaceae. Ex...

  12. Seed set, pollen morphology and pollen surface composition response to heat stress in field pea.

    Science.gov (United States)

    Jiang, Yunfei; Lahlali, Rachid; Karunakaran, Chithra; Kumar, Saroj; Davis, Arthur R; Bueckert, Rosalind A

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar. © 2015 John Wiley & Sons Ltd.

  13. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.

    Directory of Open Access Journals (Sweden)

    Melekber Sulusoglu

    2014-01-01

    Full Text Available Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.. Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride and IKI (iodine potassium iodide, were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.. Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  14. In vitro pollen viability and pollen germination in cherry laurel (Prunus laurocerasus L.).

    Science.gov (United States)

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r(2) = 0.0614 and r(2) = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  15. Controlling Hay Fever Symptoms with Accurate Pollen Counts

    Science.gov (United States)

    ... Hay fever and pollen counts Share | Controlling Hay Fever Symptoms with Accurate Pollen Counts This article has ... MD, FAAAAI Seasonal allergic rhinitis known as hay fever is caused by pollen carried in the air ...

  16. Experimental studies on mushroom and pollen drying

    Energy Technology Data Exchange (ETDEWEB)

    Midilli, Adnan; Olgun, Hayati; Ayhan, Teoman [Karadeniz Technical Univ., Mechanical Engineering Dept., Trabzon (Turkey)

    1999-07-01

    In this study, drying periods of mushrooms and pollens (for Anzer honey) were investigated. The experiments of mushrooms were carried out under both laboratory and shady- and sunny-atmospheric conditions and those of pollens were conducted in the drying cupboard heated by electric heater and under sunny atmospheric conditions. The temperature of the drying cupboard was regulated at 45degC during the drying experiment of pollen. The mass loss of pollens and the temperature of each shelf including pollens in the drying cupboard were measured. Drying curves of mushrooms and pollens for each experiment and the variation of the mass change ratio, the moisture ratio of pollens and the temperatures in the shelves with drying time were presented, respectively. Furthermore, their equations of drying curves and the average experimental uncertainty ratios were calculated based on the experimental results. It was concluded that mushrooms can be dried in the cupboards by using hot air at 50degC in a time period of 5-6 h, and the dried must be protected in vacuum, and the pollens also must be dried at temperatures between 40 and 45degC in a time period of 2.5-3 h without their losing the colour, flavour, smell and structure. The average experimental uncertainty ratio of mushrooms and pollens during the drying process were calculated to be 22 and 18% respectively. (Author)

  17. Potential role of soil calcium in recovery of paper birch following ice storm injury in Vermont, USA

    Science.gov (United States)

    Joshua M. Halman; Paul G. Schaberg; Gary J. Hawley; Christopher F. Hansen

    2011-01-01

    In recent years, an increased number of mature paper birch (Betula papyrifera Marsh.) and heart-leafed paper birch (B. papyrifera var. cordifolia (Regel) Fern.) in northeastern United States forests have exhibited decline symptoms including foliar loss, reduced fine branching, and tree mortality. We assessed crown health, radial...

  18. Aerodynamics and pollen ultrastructure in Ephedra.

    Science.gov (United States)

    Bolinder, Kristina; Niklas, Karl J; Rydin, Catarina

    2015-03-01

    Pollen dispersal is affected by the terminal settling velocity (Ut) of the grains, which is determined by their size, bulk density, and by atmospheric conditions. The likelihood that wind-dispersed pollen is captured by ovulate organs is influenced by the aerodynamic environment created around and by ovulate organs. We investigated pollen ultrastructure and Ut of Ephedra foeminea (purported to be entomophilous), and simulated the capture efficiency of its ovules. Results were compared with those from previously studied anemophilous Ephedra species.• Ut was determined using stroboscopic photography of pollen in free fall. The acceleration field around an "average" ovule was calculated, and inflight behavior of pollen grains was predicted using computer simulations. Pollen morphology and ultrastructure were investigated using SEM and STEM.• Pollen wall ultrastructure was correlated with Ut in Ephedra. The relative proportion and amount of granules in the infratectum determine pollen bulk densities, and (together with overall size) determine Ut and thus dispersal capability. Computer simulations failed to reveal any functional traits favoring anemophilous pollen capture in E. foeminea.• The fast Ut and dense ultrastructure of E. foeminea pollen are consistent with functional traits that distinguish entomophilous species from anemophilous species. In anemophilous Ephedra species, ovulate organs create an aerodynamic microenvironment that directs airborne pollen to the pollination drops. In E. foeminea, no such microenvironment is created. Ephedroid palynomorphs from the Cretaceous share the ultrastructural characteristics of E. foeminea, and at least some may, therefore, have been produced by insect-pollinated plants. © 2015 Botanical Society of America, Inc.

  19. De novo post-pollen mitosis II tobacco pollen tube transcriptome

    OpenAIRE

    Hafidh, S. (Said); Breznenová, K. (Katarína); Honys, D. (David)

    2012-01-01

    In our previous study we applied the Agilent 44K tobacco gene chip to introduce and analyze the tobacco male gametophyte transcriptome in mature pollen and 4h pollen tubes. Here we extended our analysis post-pollen mitosis II (PMII) by including a new data set obtained from more advanced stage of the ongoing progamic phase – pollen tubes cultivated in vitro for 24 h. Pollen mitosis II marks key events in the control of male gametophyte development, the production of two sperm cells. In bicell...

  20. Pollen productivity and morphology of pollen grains in two cultivars of honeyberry (Lonicera kamtschatica (Sevast. Pojark.

    Directory of Open Access Journals (Sweden)

    Małgorzata Bożek

    2012-12-01

    Full Text Available In the years 2004-2006, investigations on the abundance of pollen production in two cultivars of Lonicera kamtschatica (Sevast. Pojark. - Atut and Duet, were conducted at the Felin Experimental Farm of the Agricultural University in Lublin. Moreover, the viability of pollen grains was estimated and measurements of their size were taken. Ten flowers of both studied cultivars supplied 11.42 mg of pollen and the average pollen productivity per 1 ha of a several-years-old plantation was 30.04 kg. The pollen of the observed plants was eagerly collected by honey bees. Pollen grains of both cultivars are suboblate. Considering their size, they can be described as large ones (P=47.55 µm, E=60.37 µm. Pollen viability for both cultivars is high, about 95%.

  1. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    Science.gov (United States)

    Sénéchal, Hélène; Visez, Nicolas; Charpin, Denis; Shahali, Youcef; Peltre, Gabriel; Biolley, Jean-Philippe; Lhuissier, Franck; Couderc, Rémy; Yamada, Ohri; Malrat-Domenge, Audrey; Pham-Thi, Nhân; Poncet, Pascal; Sutra, Jean-Pierre

    2015-01-01

    This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed. PMID:26819967

  2. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    Directory of Open Access Journals (Sweden)

    Hélène Sénéchal

    2015-01-01

    Full Text Available This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed.

  3. Pollen viability and membrane lipid composition

    NARCIS (Netherlands)

    Bilsen, van D.G.J.L.

    1993-01-01

    In this thesis membrane lipid composition is studied in relation to pollen viability during storage. Chapter 1 reviews pollen viability, membranes in the dry state and membrane changes associated with cellular aging. This chapter is followed by a study of age-related changes in phospholipid

  4. Pollen Evolution in Yams (Dioscorea: Dioscoreaceae)

    NARCIS (Netherlands)

    Schols, P.; Wilkin, P.; Furness, C.; Huysmans, S.; Smets, E.

    2005-01-01

    Pollen character evolution in yams (Dioscorea: Dioscoreaceae) was investigated in relation to the phylogeny obtained from a recent combined analysis of rbcL and matK gene sequences. The following characters were evaluated: pollen size, aperture number, sexine ornamentation, perforation density, and

  5. Practical aspects of daily pollen census

    NARCIS (Netherlands)

    Quarles van Ufford, W.J.

    1967-01-01

    It is important for diagnostic purposes to keep a daily pollen count. Correlating this with hayfever symptoms, it is then possible to gain insights into critical hours and circumstances which favor an outbreak. Thus we learn to predict the severity of a pollen season and to take preventive measures.

  6. A combinatorial approach to angiosperm pollen morphology.

    Science.gov (United States)

    Mander, Luke

    2016-11-30

    Angiosperms (flowering plants) are strikingly diverse. This is clearly expressed in the morphology of their pollen grains, which are characterized by enormous variety in their shape and patterning. In this paper, I approach angiosperm pollen morphology from the perspective of enumerative combinatorics. This involves generating angiosperm pollen morphotypes by algorithmically combining character states and enumerating the results of these combinations. I use this approach to generate 3 643 200 pollen morphotypes, which I visualize using a parallel-coordinates plot. This represents a raw morphospace. To compare real-world and theoretical morphologies, I map the pollen of 1008 species of Neotropical angiosperms growing on Barro Colorado Island (BCI), Panama, onto this raw morphospace. This highlights that, in addition to their well-documented taxonomic diversity, Neotropical rainforests also represent an enormous reservoir of morphological diversity. Angiosperm pollen morphospace at BCI has been filled mostly by pollen morphotypes that are unique to single plant species. Repetition of pollen morphotypes among higher taxa at BCI reflects both constraint and convergence. This combinatorial approach to morphology addresses the complexity that results from large numbers of discrete character combinations and could be employed in any situation where organismal form can be captured by discrete morphological characters. © 2016 The Author(s).

  7. Preservation of cycad and Ginkgo pollen

    Science.gov (United States)

    Frederiksen, N.O.

    1978-01-01

    Pollen grains of Ginkgo, Cycas, and Encephalartos were chemically treated together with pollen of Quercus, Alnus, and Pinus, the latter three genera being used as standards. The experiments showed that: (1) boiling the pollen for 8-10 hours in 10% KOH had little if any effect on any of the grains; (2) lengthy acetolysis treatment produced some degradation or corrosion, particularly in Ginkgo and Cycas, but the grains of even these genera remained easily recognizable; (3) oxidation with KMnO4 followed by H2O2 showed that pollen of Ginkgo, Cycas, and Encephalartos remains better preserved than that of Quercus and Alnus, and although Ginkgo and Encephalartos probably are slightly less resistant to oxidation than Pinus, no great differences exists between these monosulcate types and Pinus. Thus the experiments show that, at least for sediments low in bacteria, cycad and Ginkgo pollen should be well represented in the fossil record as far as their preservational capabilities are concerned. ?? 1978.

  8. MICROBIAL QUALITY OF HONEY MIXTURE WITH POLLEN

    Directory of Open Access Journals (Sweden)

    Ján Mareček

    2011-02-01

    Full Text Available Normal 0 21 MicrosoftInternetExplorer4 The aim of this study was evaluation of microbial quality in raw materials (honey, pollen and evaluation of microbial quality in honey mixture with pollen (2.91 % and 3.85 % and also dynamics of microbial groups in honey mixtures with pollen after 14 days storage at the room temperature (approximately 25 °C and in cold store (8 °C. We used dilution plating method for testing of samples. Detections of total plate microbial count (aerobic and anaerobic microorganisms, sporulating bacteria, coliform bacteria, Bifidobacterium sp., Lactobacillus sp. and microscopic fungi were performed. In general, counts of microorganisms decreased in honey mixture with pollen compared to raw pollen and these counts increased compared to natural honey. Total plate count was 5.37 log KTJ.g-1 in pollen; 1.36 log KTJ.g-1 in honey; 2.97 log KTJ.g-1 in honey mixture with 2.91 % pollen and 2.04 log KTJ.g-1 in honey mixture with 3.85 % pollen. Coliform bacteria were detected in pollen (1.77 log KTJ.g-1. Then, we found coliform bacteria in one sample of honey mixtures with pollen (2.91 % - 1.00 log KTJ.g-1.Bifidobacterium species were detected only in raw pollen. We did not findLactobacillus sp. in any of the samples. Microscopic fungi were detected on two cultivating media. Yeasts were present in pollen sample (average 5.39 log KTJ.g-1, honey mixture with 2.91 % pollen (average 2.51 log KTJ.g-1 and honey mixture with 3.85 % pollen (average 1.58 log KTJ.g-1. Filamentous microscopic fungi were detectable in pollen (average 3.38 log KTJ.g-1, in honey (only on one medium: 1.00 log KTJ.g-1, in honey mixture with 2.91 % pollen (average 1.15 log KTJ.g-1 and in honey mixture with 3.85 % pollen (1.71 %. Raw pollen contained microscopic fungi as Absidiasp., Mucor sp., Alternaria sp. andEmericella nidulans. Honey mixture with 2.91 % pollen after storage (14 days contained lower microbial counts when compared with the sample

  9. Aerobiology and pollen allergy in Islamabad

    International Nuclear Information System (INIS)

    Abbas, S.; Raza, S.M.; Khan, M.A.

    2009-01-01

    Pollen allergies affect a significant proportion of Islamabad residents. Many patients with pollen allergy Are hospitalized in Islamabad in spring (February to April), fall seasons (July to September) and after monsoons. To determine the type and concentration of airborne pollens causing allergic diseases in the susceptible patients in Islamabad. The study was conducted from January 2005 to December 2006 and Burkard Volumetric Spore Trap' provided by the World Allergy Organization was used. This spore trap was placed in the F-10 area of Islamabad and samples were collected on weekly basis during the whole study period. To obtain the sample, the spore trap drum was loaded with a strip of sticky tape every week. The sampled sticky tape was then collected each week at a specified time and replaced with a fresh strip of sticky tape, which was then collected next week. This cycle , continued for whole study period. From each sample seven permanent slides were made and mounted with gelevitol mounting media; The slides were then examined microscopically. A total of 702 individuals irrespective of age or gender were included in the study. Skin prick tests were performed for pollens using allergen extracts of Hollister-Steir, USA and the results were recorded. The two flowering seasons in Islamabad i.e., spring and fall caused maximum pollen allergies. The Broussonetia papyrifera (paper mulberry) tree in spring, and the Cannabis sativa (bhang) weed in the fall season, Produced the highest seasonal pollen counts. In the spring season of 2005, Broussonetia papyrifera produced the highest pollen count, (73%) of the total pollen count, with a maximum count of 1390 pollen/cu meter of air/hour on 20th of March, while in 2006, it accounted for 75% of the total pollen-count with a maximum count of 1430 pollen/cu meter of air/hour on 10th of March. in fall Season of 2005, Cannabis sativa produced maximum pollen counts of 85 pollens/cu meter of air/hr on 18th of August, while in 2006

  10. Immunoproteomic tools are used to identify masked allergens: Ole e 12, an allergenic isoflavone reductase from olive (Olea europaea) pollen.

    Science.gov (United States)

    Castro, Lourdes; Crespo, Jesús F; Rodríguez, Julia; Rodríguez, Rosalía; Villalba, Mayte

    2015-12-01

    Proteins performing important biochemical activities in the olive tree (Olea europaea) pollen have been identified as allergens. One novel 37-kDa protein seems to be associated to the IgE-binding profile of a group of patients suffering allergy to peach and olive pollen. Three previously described olive pollen allergens exhibit very similar molecular mass. Our objective was to identify this allergen by using immunoproteomic approaches. After 2D-electrophoresis and mass spectrometry, peptide sequences from several IgE-binding spots, allowed identifying this new allergen, as well as cloning and DNA sequencing of the corresponding gene. The allergen, named Ole e 12, is a polymorphic isoflavone reductase-like protein of 308 amino acids showing 80% and 74% identity with birch and pear allergens, Bet v 6 and Pyr c 5, respectively. A prevalence of 33% in the selected population is in contrast to 4%-10% in groups of subjects suffering from pollinosis. Recombinant allergen was produced in Escherichia coli, and deeply characterised. Immunoblotting and ELISA detection as well as inhibition experiments were performed with polyclonal antisera and allergic patients' sera. The recombinant allergen retains the IgE reactivity of its natural counterpart. Close structural and immunological relationships between members of this protein family were supported by their IgG recognition in vegetable species. In summary, Ole e 12 is a minor olive pollen allergen, which gains relevance in patients allergic to peach with olive pollinosis. Proteomic approaches used to analyse this allergen provide useful tools to identify hidden allergens, relevant for several allergic populations and thus complete allergenic panels. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Antioxidants from slow pyrolysis bio-oil of birch wood: Application for biodiesel and biobased lubricants

    Science.gov (United States)

    Birch wood was slowly pyrolyzed to produce bio-oil and biochar. Slow pyrolysis conditions including reaction temperature, residence time, and particle size of the feed were optimized to maximize bio-oil yield. Particle size had an insignificant effect, whereas yields of up to 56% were achieved using...

  12. The population and seasonal dynamics of weevils developing in the soil of birch stands

    Science.gov (United States)

    E. Kula

    2003-01-01

    Curculionidae developing in the soil of birch stands in an air-polluted region were classified using the method of soil photoeclectors on the basis of their population dynamics (1986-2000) and phenology of their emergence from where they developed. In the course of 15 years we saw two evident culminations in the population density of Polydrusus undatus...

  13. Growth Response of Seedling Yellow Birch to Humus-Soil Mixtures

    Science.gov (United States)

    Carl H. Tubbs; Robert R. Oberg

    1966-01-01

    Previous observations of the establishment of yellow birch have cited the importance of mixed humus-mineral soil seedbeds. Godman and Krefting pointed out that both germination and growth were enhanced. Subsequent studies have shown that while germination in the absence of competition is adequate on mineral soil of a Podzol A under a wide variety of light and...

  14. Estimating the spread rate of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer using fluorescence

    Science.gov (United States)

    Toni Antikainen; Anti Rohumaa; Christopher G. Hunt; Mari Levirinne; Mark Hughes

    2015-01-01

    In plywood production, human operators find it difficult to precisely monitor the spread rate of adhesive in real-time. In this study, macroscopic fluorescence was used to estimate spread rate (SR) of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer. This method could be an option when developing automated real-time SR measurement for...

  15. 78 FR 50410 - Birch Power Company; Notice of Proposed Restricted Service List for a Programmatic Agreement

    Science.gov (United States)

    2013-08-19

    ... Project] Birch Power Company; Notice of Proposed Restricted Service List for a Programmatic Agreement Rule..., the Secretary may establish a restricted service list for a particular phase or issue in a proceeding. The restricted service list should contain the names of persons on the service list who, in the...

  16. Study of the betulin enriched birch bark extracts effects on human carcinoma cells and ear inflammation

    Directory of Open Access Journals (Sweden)

    Dehelean Cristina A

    2012-11-01

    Full Text Available Abstract Background Pentacyclic triterpenes, mainly betulin and betulinic acid, are valuable anticancer agents found in the bark of birch tree. This study evaluates birch bark extracts for the active principles composition. Results New improved extraction methods were applied on the bark of Betula pendula in order to reach the maximum content in active principles. Extracts were analyzed by HPLC-MS, Raman, SERS and 13C NMR spectroscopy which revealed a very high yield of betulin (over 90%. Growth inhibiting effects were measured in vitro on four malignant human cell lines: A431 (skin epidermoid carcinoma, A2780 (ovarian carcinoma, HeLa (cervix adenocarcinoma and MCF7 (breast adenocarcinoma, by means of MTT assay. All of the prepared bark extracts exerted a pronounced antiproliferative effect against human cancer cell lines. In vivo studies involved the anti-inflammatory effect of birch extracts on TPA-induced model of inflammation in mice. Conclusions The research revealed the efficacy of the extraction procedures as well as the antiproliferative and anti-inflammatory effects of birch extracts.

  17. The distribution of lignin in white birch wood as determined by bromination with TEM-EDXA

    International Nuclear Information System (INIS)

    Saka, S.; Goring, D.A.I.

    1988-01-01

    Ultraviolet absorbance and bromine uptake were measured on various morphological regions of birch wood. To facilitate precise comparison, observations were made on identical locations in successive cross sections. From the data, the concentration of lignin and the ratio of the guaiacyl to syringyl residues were determined. The results obtained were then compared with the previous findings from the use of UV microscopy alone

  18. High-Titer Methane from Organosolv-Pretreated Spruce and Birch

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2017-02-01

    Full Text Available The negative impact of fossil fuels and the increased demand for renewable energy sources has led to the use of novel raw material sources. Lignocellulosic biomass could serve as a possible raw material for anaerobic digestion and production of biogas. This work is aimed at using forest biomass, both softwood (spruce and hardwood (birch, as a raw material for anaerobic digestion. We examined the effect of different operational conditions for the organosolv pretreatment (ethanol content, duration of treatment, and addition of acid catalyst on the methane yield. In addition, we investigated the effect of addition of cellulolytic enzymes during the digestion. We found that inclusion of an acid catalyst during organosolv pretreatment improved the yields from spruce, but it did not affect the yields from birch. Shorter duration of treatment was advantageous with both materials. Methane yields from spruce were higher with lower ethanol content whereas higher ethanol content was more beneficial for birch. The highest yields obtained were 185 mL CH4/g VS from spruce and 259.9 mL CH4/g VS from birch. Addition of cellulolytic enzymes improved these yields to 266.6 mL CH4/g VS and 284.2 mL CH4/g VS, respectively.

  19. Polyoxometalate delignification of birch kraft pulp and effect on residual lignin

    Science.gov (United States)

    Biljana Bujanovic; Richard S. Reiner; Sally A. Ralph; Rajai H. Atalla

    2011-01-01

    To advance the understanding of delignification with polyoxometalates (POMs) that have been explored for use in bleaching of chemical pulps, the transformation of lignin during anaerobic treatment of birch kraft pulp with an equilibrated POM mixture composed of Na5(+2)[SiV1(-0.1)MoW10(+0.1)O

  20. Shading and root-shoot relations in saplings of silver birch, pedunculate oak and beech

    NARCIS (Netherlands)

    Hees, van A.F.M.; Clerkx, A.P.P.M.

    2003-01-01

    Silver birch (Betula pendula Roth), pedunculate oak (Quercus robur L.) and beech (Fagus sylvatica L.) can regenerate successfully under a canopy of Scots pine (Pinus sylvestris L.). Shading reduces plant growth and modifies plant form, two related aspects. This study focuses on the effects of

  1. Influence of edging practices on cutting yields of Alaska birch lumber

    Science.gov (United States)

    David L. Nicholls; J.W. Funck; C.C. Brunner; J.E. Reeb

    2009-01-01

    Birch lumber is often characterized by a high degree of knots, bark pockets, heartwood, and other features which force sawmill owners to decide whether to edge and trim boards to produce standard grade lumber vs. proprietary grade character-marked lumber. In addition, the edging strategies used with irregularly shaped flitches can greatly influence cut-stock recovery....

  2. Pollen dispersal in sugar beet production fields.

    Science.gov (United States)

    Darmency, Henri; Klein, Etienne K; De Garanbé, Thierry Gestat; Gouyon, Pierre-Henri; Richard-Molard, Marc; Muchembled, Claude

    2009-04-01

    Pollen-mediated gene flow has important implications for biodiversity conservation and for breeders and farmers' activities. In sugar beet production fields, a few sugar beet bolters can produce pollen as well as be fertilized by wild and weed beet. Since the crop, the wild beets, and the weed beets are the same species and intercross freely, the question of pollen flow is an important issue to determine the potential dispersal of transgenes from field to field and to wild habitats. We report here an experiment to describe pollen dispersal from a small herbicide-resistant sugar beet source towards male sterile target plants located along radiating lines up to 1,200 m away. Individual dispersal functions were inferred from statistical analyses and compared. Pollen limitation, as expected in root-production fields, was confirmed at all the distances from the pollen source. The number of resistant seeds produced by bait plants best fitted a fat-tailed probability distribution curve of pollen grains (power-law) dependent on the distance from the pollen source. A literature survey confirmed that power-law function could fit in most cases. The b coefficient was lower than 2. The number of fertilized flowers by background (herbicide-susceptible) pollen grains was uniform across the whole field. Airborne pollen had a fertilization impact equivalent to that of one adjacent bolter. The individual dispersal function from different pollen sources can be integrated to provide the pollen cloud composition for a given target plant, thus allowing modeling of gene flow in a field, inter-fields in a small region, and also in seed-production area. Long-distance pollen flow is not negligible and could play an important role in rapid transgene dispersal from crop to wild and weed beets in the landscape. The removing of any bolting, herbicide-resistant sugar beet should be compulsory to prevent the occurrence of herbicide-resistant weed beet, thus preventing gene flow to wild

  3. Honey bees preferentially consume freshly-stored pollen.

    Science.gov (United States)

    Carroll, Mark J; Brown, Nicholas; Goodall, Craig; Downs, Alexandra M; Sheenan, Timothy H; Anderson, Kirk E

    2017-01-01

    Honey bees (Apis mellifera) collect and store both honey and pollen in preserved forms. Pollen storage involves the addition of honey or nectar and oral secretions to pollen granules. It is controversial whether the duration of pollen storage alters the palatability or nutritive value of the pollen storage medium. We examined how bees utilize different-aged stored pollen during an extended pollen flow. The deposition of pollen into wax cells and subsequent consumption were monitored daily on 18 brood frames from 6 colonies over an 8d observation period. Despite a greater abundance of older stored pollen cells on brood frames, bees showed a marked preference for the consumption of freshly-stored pollen. Two to four day-old pollen cell contents were significantly more likely to be consumed, while pollen cell contents more than seven days old were eaten at much lower rates. Similar experiments that controlled for cell abundance and spatial effects using cage assays yielded the same result. One day-old stored pollen was consumed approximately three times more often than 10d-old stored pollen, and two times more often than 5d-old stored pollen. These consumption preferences for freshly-stored pollen occurred despite a lack of clear developmental advantages. Young adult workers reared for 7 days on 1d-, 5d-, or 10d-old stored pollen showed no difference in body mass, stored pollen consumption, hindgut fecal material accumulation, or hypopharyngeal gland (HPG) protein titers, suggesting that different-aged pollen stores did not vary in their nutritional value to adult bees. These findings are inconsistent with the hypothesis promoting a period of microbially-mediated, "beebread maturation" that results in greater palatability or nutritive value for aged pollen stores. Rather, stored pollen that is not eaten in the first few days accumulates as excess stores preserved in a less preferred, but nutritionally-similar state.

  4. Bee plant inventory and the pollen potentiality of Menagesha Suba ...

    African Journals Online (AJOL)

    The study was designed with the objectives of assessing the pollen yielding plant species and to establish, the flowering phenology of bee plants. Pollen was collected from the zander beehives using the pollen trap fitted to the entrance of beehives for two years. The pollen was identified using light microscope with a 400x ...

  5. Alnus as a disturbing factor in pollen diagrams

    NARCIS (Netherlands)

    Janssen, C.R.

    1959-01-01

    It is commonly accepted that percentages of pollen in a pollen diagram do not express the exact composition of forests in earlier times. This inaccuracy is due to several factors, for instance the different quantities of pollen produced by plants, the distance of transport etc. A pollen diagram

  6. Comparative pollen analysis of honeys from apiary and open ...

    African Journals Online (AJOL)

    Comparative pollen analysis of honeys from apiary and open markets in Nigeria and Bénin Republic. ... Eleven honey samples, six from the apiary and five from the open markets, were analysed for their pollen content. Pollen types ... Key words: Pollen, Bees, Guinea savanna, Botanical origin, Honey, Melissopalynology ...

  7. In vitro pollen quantity, viability and germination tests in quince ...

    African Journals Online (AJOL)

    Quince (Cydonia oblonga Mill.) cvs. Ekmek, Esme, Limon, Ege 2, Ege 22, Ege 25 and Quince-A rootstock pollens were collected in April from the unopened pink balloon-stage flowers on mature trees. The pollen amount was between 20063 pollen/flower ('Ege 25') and 11906 pollen/flower ('Limon') with hemacytometer.

  8. Pollen

    Science.gov (United States)

    ... About NIEHS Home Page Office of the Director Organizational Structure 2018-2023 Strategic Plan Advisory Boards & Councils Community ... Home Page About NIEHS Office of the Director Organizational Structure 2018-2023 Strategic Plan Advisory Boards & Councils Community ...

  9. Pollen Viability of Aeschynanthus tricolor Hook.

    Directory of Open Access Journals (Sweden)

    Vitri Garvita Gandadikusumah

    2017-04-01

    Full Text Available Aeschynanthus (Gesneriaceae is climbing or trailing epiphytes from the tropical forests of South-East Asia. Several species are widely cultivated for their attractive flowers, which usually scarlet with long corolla tubes and probably bird pollinated.This study was carried out on Aeschynanthus tricolor Hook. to determine in vitro germinability of (1 pollen collected from flowers at anthesis, on the day before anthesis, or up to five days after anthesis and (2 pollen collected on the day of anthesis and then stored at -20oC for 127 days. Germinability tests were carried out on pollen grains after stored for four hours in 10% sucrose solution. The highest in vitro germination percentage observed was pollen collected on the day of anthesis (96.3% and the lowest was pollen collected on the fifth day after anthesis (5.6%. The germination percentage of pollen after stored at -20oC was 98% at beginning and 22% after 127 days. From this research we can conclude that pollen of A. tricolor can be successfully collected and then stored for some time, will be practical benefit for plant breeding and conservation purposes.

  10. Pollen structure and function in caesalpinioid legumes.

    Science.gov (United States)

    Banks, Hannah; Rudall, Paula J

    2016-03-01

    A diverse range of pollen morphologies occurs within the large, paraphyletic legume subfamily Caesalpinioideae, especially among early-branching lineages. Previous studies have hypothesized an association between surface ornamentation and pollination syndrome or other aspects of pollen function such as desiccation tolerance and adaptations to accommodate volume changes. We reviewed caesalpinioid pollen morphology using light microscopy, scanning and transmission electron microscopy, in combination with a literature survey of pollination vectors. Pollen structural diversity is greatest in the early-branching tribes Cercideae and Detarieae, whereas Cassieae and Caesalpinieae are relatively low in pollen diversity. Functional structures to counter desiccation include opercula (lids) covering apertures and reduced aperture size. Structures preventing wall rupture during dehydration and rehydration include different forms of colpi (syncolpi, parasyncolpi, pseudocolpi), striate supratectal ornamentation, and columellate or granular wall structures that resist tensile or compressive forces respectively. Specialized aperture structures (Zwischenkörper) may be advantageous for efficient germination of the pollen tube. In Detarieae and Cercideae in particular, there is potential to utilize pollen characters to estimate pollination systems where these are unknown. Supratectal verrucae and gemmae have apparently evolved iteratively in Cercideae and Detarieae. At the species level, there is a potential correlation between striate/verrucate patterns and vertebrate pollination. © 2016 Botanical Society of America.

  11. Impacts of Elevated Atmospheric CO2 and O3 on Paper Birch (Betula papyrifera: Reproductive Fitness

    Directory of Open Access Journals (Sweden)

    Joseph N. T. Darbah

    2007-01-01

    Full Text Available Atmospheric CO2 and tropospheric O3 are rising in many regions of the world. Little is known about how these two commonly co-occurring gases will affect reproductive fitness of important forest tree species. Here, we report on the long-term effects of CO3 and O3 for paper birch seedlings exposed for nearly their entire life history at the Aspen FACE (Free Air Carbon Dioxide Enrichment site in Rhinelander, WI. Elevated CO2 increased both male and female flower production, while elevated O3 increased female flower production compared to trees in control rings. Interestingly, very little flowering has yet occurred in combined treatment. Elevated CO2 had significant positive effect on birch catkin size, weight, and germination success rate (elevated CO2 increased germination rate of birch by 110% compared to ambient CO2 concentrations, decreased seedling mortality by 73%, increased seed weight by 17%, increased root length by 59%, and root-to-shoot ratio was significantly decreased, all at 3 weeks after germination, while the opposite was true of elevated O3 (elevated O3 decreased the germination rate of birch by 62%, decreased seed weight by 25%, and increased root length by 15%. Under elevated CO2, plant dry mass increased by 9 and 78% at the end of 3 and 14 weeks, respectively. Also, the root and shoot lengths, as well as the biomass of the seedlings, were increased for seeds produced under elevated CO2, while the reverse was true for seedlings from seeds produced under the elevated O3. Similar trends in treatment differences were observed in seed characteristics, germination, and seedling development for seeds collected in both 2004 and 2005. Our results suggest that elevated CO2 and O3 can dramatically affect flowering, seed production, and seed quality of paper birch, affecting reproductive fitness of this species.

  12. Bee Pollen: Chemical Composition and Therapeutic Application

    Directory of Open Access Journals (Sweden)

    Katarzyna Komosinska-Vassev

    2015-01-01

    Full Text Available Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process.

  13. Pollen-projektiga Rootsis / Lembit Jakobson

    Index Scriptorium Estoniae

    Jakobson, Lembit

    2009-01-01

    Avastusõppe projektist "Pollen" Eesti (2006-2009) mille eesmärk on kõiki lapsi kaasav uurimisõpe. Kevadisel koolivaheajal tutvus kümmekond Eesti õpetajat uurimisõppega Stockholmi kahes algkoolis

  14. Intraspecific variation in pollen viability, germination and ...

    African Journals Online (AJOL)

    Oleaceae) cultivars 'Koroneiki', 'Mastoidis' and 'Kalamata' was studied with scanning electron microscopy to identify genotype- distinguishing characters that could be employed for morphological cultivar discrimination. Pollen viability and germination ...

  15. Evolutionarily conserved phenylpropanoid pattern on angiosperm pollen.

    Science.gov (United States)

    Fellenberg, Christin; Vogt, Thomas

    2015-04-01

    The male gametophyte of higher plants appears as a solid box containing the essentials to transmit genetic material to the next generation. These consist of haploid generative cells that are required for reproduction, and an invasive vegetative cell producing the pollen tube, both mechanically protected by a rigid polymer, the pollen wall, and surrounded by a hydrophobic pollen coat. This coat mediates the direct contact to the biotic and abiotic environments. It contains a mixture of compounds required not only for fertilization but also for protection against biotic and abiotic stressors. Among its metabolites, the structural characteristics of two types of phenylpropanoids, hydroxycinnamic acid amides and flavonol glycosides, are highly conserved in Angiosperm pollen. Structural and functional aspects of these compounds will be discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Pollen fertility studies in Jatropha L.

    OpenAIRE

    Sasikala. R; M.Paramathma; R. Kalaiyarasi

    2009-01-01

    Pollen fertility percentage is conducted for 10 Jatropha species and an interspecific backcrossing hybrid between Jatrophacurcas x Jatropha integerrima (BC3F1). Totally nine species namely Jatropha villosa var. villosa , Jatropha villosa var.villosa , Jatropha multifida, Jatropha podagrica, Jatropha maheswarii, Jatropha glandulifera, Jatropha gossypifolia,Jatropha integerrima and Jatropha curcas had more than 84 per cent of pollen fertility. BC3F1 hybrid recorded the highestpollen fertility p...

  17. Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

    Science.gov (United States)

    Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Kubin, Eero; Linkosalmi, Maiju; Melih Tanis, Cemal; Nadir Arslan, Ali

    2017-04-01

    Ecosystems' potential to provide services, e.g. to sequester carbon is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support various analyses of ecosystem functioning. We established a network of cameras for automated monitoring of phenological activity of vegetation in boreal ecosystems of Finland. Cameras were mounted on 14 sites, each site having 1-3 cameras. In this study, we used cameras at 11 of these sites to investigate how well networked cameras detect phenological development of birches (Betula spp.) along the latitudinal gradient. Birches are interesting focal species for the analyses as they are common throughout Finland. In our cameras they often appear in smaller quantities within dominant species in the images. Here, we tested whether small scattered birch image elements allow reliable extraction of color indices and changes therein. We compared automatically derived phenological dates from these birch image elements to visually determined dates from the same image time series, and to independent observations recorded in the phenological monitoring network from the same region. Automatically extracted season start dates based on the change of green color fraction in the spring corresponded well with the visually interpreted start of season, and field observed budburst dates. During the declining season, red color fraction turned out to be superior over green color based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with gradients based on phenological field observations from the same region. We conclude that already small and scattered birch image elements allow reliable extraction of key phenological dates for birch species. Devising cameras for species specific analyses of phenological timing will be useful for

  18. Hydrogenated graphenes by birch reduction: influence of electron and proton sources on hydrogenation efficiency, magnetism, and electrochemistry

    Czech Academy of Sciences Publication Activity Database

    Eng, A.Y.S.; Sofer, Z.; Huber, Š.; Bouša, D.; Maryško, Miroslav; Pumera, M.

    2015-01-01

    Roč. 21, č. 7 (2015), 16828-16838 ISSN 0947-6539 Institutional support: RVO:68378271 Keywords : hydrogenated graphenes * birch reduction * magnetism * electrochemistry * hydrogenation efficiency Subject RIV: CA - Inorganic Chemistry Impact factor: 5.771, year: 2015

  19. Pollen-related allergy in Europe.

    Science.gov (United States)

    D'Amato, G; Spieksma, F T; Liccardi, G; Jäger, S; Russo, M; Kontou-Fili, K; Nikkels, H; Wüthrich, B; Bonini, S

    1998-06-01

    The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropalynologic and allergologic studies have progressed to meet this need, and extensive international networks now provide regular pollen and hay-fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently, pollen calendars differ from one area to another; however, on the whole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Europe, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Mediterranean areas favor the production of pollen types that are rarely found in central and northern areas of the continent (e.g., the genera Parietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultural factors (e.g., importation of plants for urban parklands) and greater international travel (e.g., the expansion of the ragweed genus Ambrosia in France, northern Italy, Austria, and Hungary). Studies on allergen-carrying paucimicronic or submicronic airborne particles, which penetrate deep into the lung, are having a relevant impact on our understanding of pollinosis and its distribution throughout Europe.

  20. Plant Sterol Diversity in Pollen from Angiosperms.

    Science.gov (United States)

    Villette, Claire; Berna, Anne; Compagnon, Vincent; Schaller, Hubert

    2015-08-01

    Here we have examined the composition of free sterols and steryl esters of pollen from selected angiosperm species, as a first step towards a comprehensive analysis of sterol biogenesis in the male gametophyte. We detected four major sterol structural groups: cycloartenol derivatives bearing a 9β,19-cyclopropyl group, sterols with a double bond at C-7(8), sterols with a double bond at C-5(6), and stanols. All these groups were unequally distributed among species. However, the distribution of sterols as free sterols or as steryl esters in pollen grains indicated that free sterols were mostly Δ(5)-sterols and that steryl esters were predominantly 9β,19-cyclopropyl sterols. In order to link the sterol composition of a pollen grain at anthesis with the requirement for membrane lipid constituents of the pollen tube, we germinated pollen grains from Nicotiana tabacum, a model plant in reproductive biology. In the presence of radiolabelled mevalonic acid and in a time course series of measurements, we showed that cycloeucalenol was identified as the major neosynthesized sterol. Furthermore, the inhibition of cycloeucalenol neosynthesis by squalestatin was in full agreement with a de novo biogenesis and an apparent truncated pathway in the pollen tube.

  1. Ragweed (Ambrosia) pollen source inventory for Austria.

    Science.gov (United States)

    Karrer, G; Skjøth, C A; Šikoparija, B; Smith, M; Berger, U; Essl, F

    2015-08-01

    This study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004-2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe. A method for constructing top-down pollen source inventories for invasive ragweed plants in Austria, a country that is challenging in terms of topography and ragweed distribution. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  2. Influence of pollen nutrition on honey bee health: do pollen quality and diversity matter?

    Directory of Open Access Journals (Sweden)

    Garance Di Pasquale

    Full Text Available Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens and diversity (polyfloral pollen diet on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level, and on the tolerance to the microsporidian parasite Nosemaceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification, phenoloxidase (immunity and alkaline phosphatase (metabolism. We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health.

  3. Flowering and the Pollen Fertility in Iranian Garlic Clones

    Directory of Open Access Journals (Sweden)

    A. R. Abbasifar

    2015-06-01

    Full Text Available Garlic (Allium sativum L. cannot produce seed because it is a sterile plant. For studying bolting and determination of pollen fertility, 68 Iranian garlic clones were gathered from different parts of Iran and evaluated in Research Field of Horticultural Department, Faculty of Agriculture, Bu-Ali Sina University in 2010-2011 and 2011-2012. For determining the pollen fertility, some tests including specific RAPD marker, pollen germination, pollen viability detection using acetocarmine and in vitro culture of ovules and fruits were used. Results showed that 37 of Iranian garlic clones could produce scape and inflorescence. The percentage range of pollen stained with acetocarmine was from 0.5 up to 20 percent showing infertility of pollens. Lack of two markers (OPJ121300 and OPJ121700 and pollen tube growth proved the infertility of garlic clones pollen. Fruits and embryo sac were alive for more than two months, showing their potential for producing seeds following pollination with fertile pollens.

  4. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Orby, P.V.; Skjoth, C. A.

    2014-01-01

    In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  5. Gametophytic Pollen Tube Guidance: Attractant Peptides, Gametic Controls, and Receptors.

    Science.gov (United States)

    Higashiyama, Tetsuya; Yang, Wei-Cai

    2017-01-01

    Pollen tube guidance in flowering plants is a unique and critical process for successful sexual reproduction. The pollen tube that grows from pollen, which is the male gametophyte, precisely navigates to the embryo sac, which is the female gametophyte, within the pistil. Recent advances have clarified the molecular framework of gametophytic pollen tube guidance. Multiple species-specific attractant peptides are secreted from synergid cells, the proper development and function of which are regulated by female gametes. Multiple receptor-like kinases on the pollen tube tip are involved in sensing species-specific attractant peptides. In this Update article, recent progress in our understanding of the mechanism of gametophytic pollen tube guidance is reviewed, including attraction by synergid cells, control of pollen tube guidance by female gametes, and directional growth of the pollen tube by directional cue sensing. Future directions in the study of pollen tube guidance also are discussed. © 2017 American Society of Plant Biologists. All Rights Reserved.

  6. Arabidopsis adaptor protein 1G is critical for pollen development.

    Science.gov (United States)

    Feng, Chong; Wang, Jia-Gang; Liu, Hai-Hong; Li, Sha; Zhang, Yan

    2017-09-01

    Pollen development is a pre-requisite for sexual reproduction of angiosperms, during which various cellular activities are involved. Pollen development accompanies dynamic remodeling of vacuoles through fission and fusion, disruption of which often compromises pollen viability. We previously reported that the Y subunit of adaptor protein 1 (AP1G) mediates synergid degeneration during pollen tube reception. Here, we demonstrate that AP1G is essential for pollen development. AP1G loss-of-function resulted in male gametophytic lethality due to defective pollen development. By ultrastructural analysis and fluorescence labeling, we demonstrate that AP1G loss-of-function compromised dynamic vacuolar remodeling during pollen development and impaired vacuolar acidification of pollen. Results presented here support a key role of vacuoles in gametophytic pollen development. © 2017 Institute of Botany, Chinese Academy of Sciences.

  7. Marking live conifer pollen for long-distance dispersal experiments.

    Science.gov (United States)

    Williams, Claire G; von Aderkas, Patrick

    2011-01-01

    Study of long-distance dispersal (LDD) theory requires a method for marking live LDD pollen. Such a method must complement the more intensive sampling methods involving molecular cytogenetics, proteomics, and genomics. We have developed a new method for marking live Pinus taeda pollen using two dyes, rhodamine 123 and aniline blue, dissolved in a sucrose solution. Marked and unmarked pollen were compared with respect to in vitro germination, storage, terminal velocity and in vivo pollen-tube penetration of ovules. We found that: (1) both types of marked pollen retained their capacity for germination, (2) both types of marked pollen had similar aerodynamic properties as unmarked pollen controls, (3) marked pollen retained its germination capacity for 48 h, and (4) of the marked pollen, only the aniline-marked pollen penetrated ovules during pollination. Germination declined rapidly for both types of marked pollen after 48 h and before 37 days at -20°C storage, while the unmarked pollen lots retained 93% germination at all stages. Our method for marking live P. taeda pollen is feasible for tracing LDD pollen if released and deposited within 48 h of dye treatment.

  8. A 12,000-Yr Pollen Record off Cape Hatteras: Pollen Sources and Mechanisms of Pollen Dispersion

    Science.gov (United States)

    Naughton, F.; Keigwin, L.; Peteet, D.; Costas, S.; Desprat, S.; Oliveira, D.; de Vernal, A.; Voelker, A.; Abrantes, F.

    2015-01-01

    Integrating both marine and terrestrial signals from the same sediment core is one of the primary challenges for understanding the role of ocean-atmosphere coupling throughout past climate changes. It is therefore vital to understand how the pollen signal of a given marine record reflects the vegetation changes of the neighboring continent. The comparison between the pollen record of marine core JPC32 (KNR178JPC32) and available terrestrial pollen sequences from eastern North America over the last 12,170 years indicates that the pollen signature off Cape Hatteras gives an integrated image of the regional vegetation encompassing the Pee Dee river, Chesapeake and Delaware hydrographic basins and is reliable in reconstructing the past climate of the adjacent continent. Extremely high quantities of pollen grains included in the marine sediments off Cape Hatteras were transferred from the continent to the sea, at intervals 10,100-8800 cal yr BP, 8300-7500 cal yr BP, 5800- 4300 cal yr BP and 2100-730 cal yr BP, during storm events favored by episodes of rapid sea-level rise in the eastern coast of US. In contrast, pollen grains export was reduced during 12,170-10,150 cal yr BP and 4200- 2200 cal yr BP, during episodes of intense continental dryness and slow sea level rise episodes or lowstands in the eastern coast of US. The near absence of reworked pollen grains in core JPC32 contrasts with the high quantity of reworked material in nearby but deeper located marine sites, suggesting that the JPC32 recordwas not affected by the DeepWestern Boundary Current (DWBC) since the end of the Younger Dryas and should be considered a key site for studying past climate changes in the western North Atlantic.

  9. Response of winter chemical defense in Alaska paper birch and green alder to manipulation of plant carbon/nutrient balance.

    Science.gov (United States)

    Bryant, J P; Chapin, F S; Reichardt, P B; Clausen, T P

    1987-07-01

    Plant carbon/nutrient balance has been implicated as an important factor in plant defensive chemistry and palatability to herbivores. We tested this hypothesis by fertilizing juvenile growth form Alaska paper birch and green alder with N, P and N-plus-P in a balanced 2x2 factorial experiment. Additionally, we shaded unfertilized plants of both species. Fertilization with N and N-plus-P increased growth of Alaska paper birch, reduced the concentration of papyriferic acid in internodes and increased the palatability of birch twigs to snowshoe hares. Shading decreased birch growth, decreased the concentration of papyriferic acid in internodes and increased twig palatability. These results indicate that the defensive chemistry and palatability of winter-dormant juvenile Alaska paper birch are sensitive to soil fertility and shade. Conversely the defensive chemistry and palatability of green alder twigs to snowshoe hares were not significantly affected by soil fertility or shade. The greater sensitivity of Alaska paper birch defensive chemistry and palatability to snowshoe hares in comparison to green alder is in agreement with the hypothesis that early successional woody plants that are adapted to high resource availability are more plastic in their chemical responses to the physical environment than are species from less favorable environments.

  10. Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

    Directory of Open Access Journals (Sweden)

    Martens Maria

    2011-12-01

    Full Text Available Abstract Background The botanical relation between grass and cereal grains may be relevant when diagnosing food allergy to cereals. The aim was to investigate the diagnostic specificity of skin prick test (SPT and specific immunoglobulin E (sIgE tests to cereals and peanut in grass pollen allergic subjects without history of, and clinically reactions to foods botanically related to grass. Methods 70 subjects (41 females; mean age 32 years and 20 healthy controls (13 females; mean age 24 years were tested by open food challenge (OFC with cereals and peanut. SPT and sIgE both with Immulite® (Siemens and ImmunoCAP® (Phadia to grass and birch pollen, cereals, peanut and bromelain were performed. Results Of the 65 OFC-negative subjects 29-46% (SPT, depending on cut-off, 20% (Immulite and 38% (ImmunoCAP had positive results to one or more of the foods tested. Controls were negative in all tests. Cross-reactive carbohydrate determinants (CCD as evidenced by reaction to bromelain could explain only a minority of the measured IgE-sensitizations. Conclusion Grass pollen allergic patients with documented food tolerance to cereals and peanut may express significant sensitization. False-positive cereal or peanut allergy diagnoses may be a quantitatively important problem both in routine clinical work and epidemiological studies.

  11. Pollen of Southeast Asian Alchornea (Euphorbiaceae), with an overview of the pollen fossil record

    NARCIS (Netherlands)

    Bulalacao, L.J.; Ham, van der R.W.J.M.

    2003-01-01

    In order to evaluate pollen morphological descriptions of Alchornea in the literature, which are almost completely based on African and American species, the pollen of eight Southeast Asian species of Alchornea was investigated, using light and scanning electron microscopy. Very little variation

  12. Pollen and non-pollen palynomorphs from the Early Neolithic settlement of La Draga (Girona, Spain)

    NARCIS (Netherlands)

    Revelles, J.; Burjachs, F.; van Geel, B.

    2016-01-01

    Pollen and non-pollen palynomorphs (NPP) from the Early Neolithic settlement of La Draga have provided new palaeoenvironmental data concerning the establishment of the first farming societies in NE Iberian Peninsula. The analysis of samples from the archaeological profiles allowed the comprehension

  13. Storage and irradiation of Cucumis pollen and their influence on pollen vitality

    International Nuclear Information System (INIS)

    Oost, E.H.; Nijs, A.P.M. den

    1979-01-01

    In connection with an interspecific hybridization programme and a mentor pollen experiment in Cucumis, the optimal storage conditions and in vitro germination medium for both fresh and irradiated pollen of the cultivated cucumber and two wild African Cucumis species have been searched for. (Auth.)

  14. De novo post-pollen mitosis II tobacco pollen tube transcriptome

    Czech Academy of Sciences Publication Activity Database

    Hafidh, Said; Breznenová, Katarína; Honys, David

    2012-01-01

    Roč. 7, č. 8 (2012), s. 918-921 ISSN 1559-2316 R&D Projects: GA ČR GPP501/11/P321; GA ČR GA522/09/0858 Institutional research plan: CEZ:AV0Z50380511 Keywords : de novo pollen tube transcriptome * male gametophyte development * pollen tube growth Subject RIV: ED - Physiology

  15. Stability of transgenes in long-term micropropagation of plants of transgenic birch (Betula platyphylla).

    Science.gov (United States)

    Zeng, Fansuo; Qian, Jingjing; Luo, Wei; Zhan, Yaguang; Xin, Ying; Yang, Chuanping

    2010-01-01

    The stability of integration and expression level of transgenes in long-term micropropagation clones of transgenic birch (Betula platyphylla Suk.) was examined. Multiplexed PCR and reverse primer PCR demonstrated stable integration of transgenes into regenerated plants. Expression levels of the bgt and gus genes among shoot plantlets, subcultured 4, 7, 9 and 15 times, were significantly different. The transcriptional expression level of extraneous genes in regenerated plants decreased with increasing subculture number. Transcriptional gene silencing (TGS) occured in regenerated transgenic lines. The silencing rate of GUS in the 5th subculture plants was 22-65%. TGS in regenerated plants could be reactivated with 5-azacytidine (Azac) at 50-200 microM. GUS and BGT protein expression was reactivated in the micropropagated transgenic birch plants when treated with Azac. A decrease in expression level with increasing number of subcultures is thus associated with DNA methylation.

  16. Morphological and molecular characteristics of foliar nematode attacking silver birch (Betula pendula Roth in Poland

    Directory of Open Access Journals (Sweden)

    Chałańska A.

    2017-09-01

    Full Text Available Aphelenchoides fragariae (Ritzema Bos, 1890 Christie, 1932 was isolated from leaves of silver birch (Betula pendula Roth seedlings proving that the source of infection was anemones plants. This is the first report to our best knowledge showing that the source of nematode infection of a woody plant could be a perennial plant. A. fragariae was identified by morphometric and molecular analyses. Morphological diagnosis based on the bending shape of the tail of males and pronounced apex and rostrum proved to be the most accurate reliable characteristic. On the opposite, the high variability of the mucron shape in female tails made the identification by microscopic analyses difficult. Identification of the species was confirmed by analysis of 28S rDNA sequences. The morphometric data of adults extracted from silver birch was compared with that of nematodes isolated from Anemone hupehensis (Lemoine Lemoine. Males body length varied highly in samples collected from both host plant species.

  17. Effect of Different Pretreatment Methods on Birch Outer Bark: New Biorefinery Routes

    Directory of Open Access Journals (Sweden)

    Anthi Karnaouri

    2016-03-01

    Full Text Available A comparative study among different pretreatment methods used for the fractionation of the birch outer bark components, including steam explosion, hydrothermal and organosolv treatments based on the use of ethanol/water media, is reported. The residual solid fractions have been characterized by ATR-FTIR, 13C-solid-state NMR and morphological alterations after pretreatment were detected by scanning electron microscopy. The general chemical composition of the untreated and treated bark including determination of extractives, suberin, lignin and monosaccharides was also studied. Composition of the residual solid fraction and relative proportions of different components, as a function of the processing conditions, could be established. Organosolv treatment produces a suberin-rich solid fraction, while during hydrothermal and steam explosion treatment cleavage of polysaccharide bonds occurs. This work will provide a deeper fundamental knowledge of the bark chemical composition, thus increasing the utilization efficiency of birch outer bark and may create possibilities to up-scale the fractionation processes.

  18. Properties of plasticized composite films prepared from nanofibrillated cellulose and birch wood xylan

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Blomfeldt, Thomas O. J.; Hedenqvist, Mikael S.

    2012-01-01

    Xylans, an important sub-class of hemicelluloses, represent a largely untapped resource for new renewable materials derived from biomass. As with other carbohydrates, nanocellulose reinforcement of xylans is interesting as a route to new bio-materials. With this in mind, birch wood xylan was comb......Xylans, an important sub-class of hemicelluloses, represent a largely untapped resource for new renewable materials derived from biomass. As with other carbohydrates, nanocellulose reinforcement of xylans is interesting as a route to new bio-materials. With this in mind, birch wood xylan...... was combined with nanofibrillated cellulose (NFC) and films were cast with and without glycerol, sorbitol or methoxypolyethylene glycol (MPEG) as plasticizers. Microscopy revealed some NFC agglomeration in the composite films as well as a layered nanocellulose structure. Equilibrium moisture content...

  19. The clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults

    DEFF Research Database (Denmark)

    Osterballe, M.; Hansen, T.K.; Mørtz, Charlotte G

    2005-01-01

    season. OBJECTIVE: The aim of this study was to estimate the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults and to examine the diagnostic value of skin-prick test (SPT), histamine release and specific IgE compared with the outcome......BACKGROUND: Previous studies have described cross-reactivity between fresh fruits, vegetables and pollen. However, no data demonstrates the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults with and without symptoms in the pollen...... to fruits and vegetables in pollen-sensitized adults, but also a discrepancy between the prevalence of sensitization to fruits and vegetables and the clinical relevance in different pollen-sensitized groups with symptoms in the pollen season as a significant factor....

  20. Pollen grain sporoderm and types of dispersal units

    Directory of Open Access Journals (Sweden)

    Ettore Pacini

    2014-01-01

    Full Text Available The pollen of gymnosperms and angiosperms may be dispersed in monads, tetrads, polyads, massulae or compact pollinia. The monads and tetrads may form larger clumps of pollen because filiform pollen is tangled while other kinds of pollen can be glued by means of different devices. Exine and intine modify their structure to adapt to pollen dispersing units, exine in some cases can be absent. An additional layer, a thin callosic wall, can be present in some species beneath the intine; this occurs when pollen grains are slightly dehydrated before dispersal.

  1. Early flowering and seed production in a yellow birch progeny test

    Science.gov (United States)

    Knud E. Clausen

    1976-01-01

    Trees in a yellow birch progeny test began to bear seed when 7 years old and the proportion of fruiting trees increased in the following 2 years. Male catkins were produced at age 8 and the number of trees with males increased greatly the following years. Although there is much variation between and within families in earliness of flowering and in number of flowers and...

  2. Shelf life extension and sensory evaluation of birch tree sap using chemical preservatives

    Directory of Open Access Journals (Sweden)

    Maciej Bilek

    2016-10-01

    Full Text Available The aim of this study was to assess the stability of the birch tree sap, depending on the addition and concentration of two chemical factors, ie. potassium sorbate and acids: malic, citric or lactic. As in our previous studies we found that the optimal physical parameter to assess the stability of birch sap is turbidity measurement, we used turbidimeter for estimate the effectiveness of shelf life extending. Sensory evaluation was carried out by university sensory panel with 8 skilled people (students and teachers with pre-selection and basic training of sensory methodology. On the other hand artificial perception measurements were realized by electronic nose. Birch tree sap stability without addition of preservatives, both room temperature and refrigerated, is less than three days. The effectiveness of preservation of birch tree sap depends on the concentration of acids. Independently of storage temperature, samples that received stability during the whole one-month storage period, were those with potassium sorbate and three acids in the highest concentrations, ie. malic acid at 0.3%, citric acid at 0.5% and lactic acid at 0.5%. Unfortunately, concentrations of acids, which allow extension of shelf life at least for one month in a room temperature, are characterized by the worst sensory evaluation rating. Thus, they should be corrected by the use of additives for improving the flavor, such as fruit syrups or herbal extracts. On the other hand, additionally storage in a refrigerated conditions allows one-month-stability for the sample with the highest sensory evaluation rating, ie. with the addition of lactic acid at 0.1% and potassium sorbate, which taste not need to be corrected.

  3. Growth and Yield of 15-Year Plantations of Pine, Spruce and Birch in Agricultural Land

    Directory of Open Access Journals (Sweden)

    Daugaviete Mudrite

    2017-07-01

    Full Text Available The growth data and the potential returns from 15-year-old plantations of pine Pinus sylvestris L. (6 trial sites, spruce Picea abies Karst L. (9 trial sites and silver birch Betula pendula Roth (13 trial sites, established in abandoned agricultural lands in a variety of soil types (sod calcareous, anthrosols, podzolic, podzols, gley, podzolic gley, alluvial, using the planting density 2,500 and 3,300 and also 5,000 trees/ha are analysed.

  4. Root biomass production in young birch stands planted at four spacings on two different sites

    OpenAIRE

    Johansson, Tord

    2009-01-01

    The spatial distribution of trees above ground influences on the amount of root biomass and a low root biomass might decrease the total biomass production. The amount of biomass for fractions and distribution of downy and silver birch root systems was studied including the root distribution in cardinal points. The allometric relationship between stump diameter (DSH) and stump weight and between DSH and root weight and length for the two species was quantified. The 12-year-old trees had been g...

  5. Elevated Air Humidity Changes Soil Bacterial Community Structure in the Silver Birch Stand

    OpenAIRE

    Truu, Marika; Ostonen, Ivika; Preem, Jens-Konrad; L?hmus, Krista; N?lvak, Hiie; Ligi, Teele; Rosenvald, Katrin; Parts, Kaarin; Kupper, Priit; Truu, Jaak

    2017-01-01

    Soil microbes play a fundamental role in forest ecosystems and respond rapidly to changes in the environment. Simultaneously with the temperature increase the climate change scenarios also predict an intensified hydrological cycle for the Baltic Sea runoff region. The aim of this study was to assess the effect of elevated air humidity on the top soil microbial community structure of a silver birch (Betula pendula Roth.) stand by using a free air humidity manipulation facility (FAHM). The bact...

  6. Elevated Air Humidity Changes Soil Bacterial Community Structure in the Silver Birch Stand.

    Science.gov (United States)

    Truu, Marika; Ostonen, Ivika; Preem, Jens-Konrad; Lõhmus, Krista; Nõlvak, Hiie; Ligi, Teele; Rosenvald, Katrin; Parts, Kaarin; Kupper, Priit; Truu, Jaak

    2017-01-01

    Soil microbes play a fundamental role in forest ecosystems and respond rapidly to changes in the environment. Simultaneously with the temperature increase the climate change scenarios also predict an intensified hydrological cycle for the Baltic Sea runoff region. The aim of this study was to assess the effect of elevated air humidity on the top soil microbial community structure of a silver birch ( Betula pendula Roth.) stand by using a free air humidity manipulation facility (FAHM). The bacterial community structures of bulk soil and birch rhizosphere were analyzed using high-throughput sequencing of bacteria-specific16S rRNA gene fragments and quantification of denitrification related genes. The increased air humidity altered both bulk soil and rhizosphere bacterial community structures, and changes in the bacterial communities initiated by elevated air humidity were related to modified soil abiotic and biotic variables. Network analysis revealed that variation in soil bacterial community structural units is explained by altered abiotic conditions such as increased pH value in bulk soil, while in rhizosphere the change in absorptive root morphology had a higher effect. Among root morphological traits, the absorptive root diameter was strongest related to the bacterial community structure. The changes in bacterial community structures under elevated air humidity are associated with shifts in C, N, and P turnover as well as mineral weathering processes in soil. Increased air humidity decreased the nir and nosZ gene abundance in the rhizosphere bacterial community. The potential contribution of the denitrification to the N 2 O emission was not affected by the elevated air humidity in birch stand soil. In addition, the study revealed a strong link between the bacterial community structure, abundance of denitrification related genes, and birch absorptive root morphology in the ecosystem system adaptation to elevated air humidity.

  7. Mountain birch – potentially large source of sesquiterpenes into high latitude atmosphere

    Directory of Open Access Journals (Sweden)

    A. Arneth

    2009-11-01

    Full Text Available Emissions of volatile organic compounds (VOCs from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June–August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average α-farnesene emission potential in 2006 was almost 2600 ng gdw−1 h−1 (3.5 pmol gdw−1 s−1 while in 2007 α-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of α-farnesene, and the effect may last for several years.

  8. Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches

    International Nuclear Information System (INIS)

    Manninen, S.; Huttunen, S.; Vanhatalo, M.; Pakonen, T.; Haemaelaeinen, A.

    2009-01-01

    We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O 3 ) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O 3 , i.e. O 3 levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O 3 and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels. - Northern birches are responsive to ambient ozone levels.

  9. Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, Stefania, E-mail: spas@unipg.it [Department of Applied Biology, University of Perugia, Perugia (Italy); Tedeschini, Emma; Frenguelli, Giuseppe [Department of Applied Biology, University of Perugia, Perugia (Italy); Wopfner, Nicole; Ferreira, Fatima [Department of Molecular Biology, CD Laboratory for Allergy Diagnosis and Therapy, University of Salzburg, Salzburg (Austria); D' Amato, Gennaro [Division of Respiratory and Allergic Diseases, ' A. Cardarelli' High Speciality Hospital, Naples (Italy); Ederli, Luisa [Department of Applied Biology, University of Perugia, Perugia (Italy)

    2011-10-15

    Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O{sub 3}) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O{sub 3} fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O{sub 3} fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O{sub 3}, determined from the mRNA levels of the major allergens. We conclude that O{sub 3} can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: > O{sub 3} reduces the viability of ragweed pollen. > ROS and allergens of ragweed pollen were not affected by O{sub 3} exposure. > O{sub 3} enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. > O{sub 3} increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

  10. More than sixty origins of pantoporate pollen in angiosperms.

    Science.gov (United States)

    Prieu, Charlotte; Sauquet, Hervé; Gouyon, Pierre-Henri; Albert, Béatrice

    2017-12-01

    Apertures in pollen grains are key structures of the wall, involved in pollen tube germination and exchanges with the environment. Aperture types in angiosperms are diverse, but pollen with one and three apertures (including monosulcate and tricolpate, respectively) are the two most common types. Here, we investigate the phylogenetic distribution in angiosperms of pollen with many round, scattered apertures called pantoporate pollen. We constructed a morphological data set with species producing pantoporate pollen and representative angiosperm species with other pollen types, sampled from every angiosperm order, with a total of 1260 species distributed in 330 families. This data set was analyzed with parsimony to characterize the phylogenetic distribution of pantoporate pollen in angiosperms. We show that pantoporate pollen is distributed throughout most of the angiosperm tree, including early diverging angiosperms, monocots, and eudicots. However, this pollen type is usually restricted to a few species in a given group, and is seldom fixed at large taxonomical scales, with a few notable exceptions. Pantoporate pollen evolved many times during angiosperm history, but the persistence of this morphology in the long term is infrequent. This distribution pattern could indicate conflicting short-term and long-term selective pressures, pantoporate pollen being selected in the short run, but eliminated in the long run. Biological hypotheses supporting this scenario are discussed, in the context of both theoretical and empirical data on pollen biology. © 2017 Botanical Society of America.

  11. Pollen and spore monitoring in the world.

    Science.gov (United States)

    Buters, J T M; Antunes, C; Galveias, A; Bergmann, K C; Thibaudon, M; Galán, C; Schmidt-Weber, C; Oteros, J

    2018-01-01

    Ambient air quality monitoring is a governmental duty that is widely carried out in order to detect non-biological ("chemical") components in ambient air, such as particles of world and to create an interactive visualization of their distribution. The method employed to collect information was based on: (a) a review of the recent and historical bibliography related to pollen and fungal spore monitoring, and (b) personal surveys of the managers of national and regional monitoring networks. The interactive application was developed using the R programming language. We have created an inventory of the active pollen and spore monitoring stations in the world. There are at least 879 active pollen monitoring stations in the world, most of which are in Europe (> 500). The prevalent monitoring method is based on the Hirst principle (> 600 stations). The inventory is visualised as an interactive and on-line map. It can be searched, its appearance can be adjusted to the users' needs and it is updated regularly, as new stations or changes to those that already exist can be submitted online. The map shows the current situation of pollen and spore monitoring and facilitates collaboration among those individuals who are interested in pollen and spore counts. It might also help to improve the monitoring of biological particles up to the current level employed for non-biological components.

  12. Compound pollen cone in a Paleozoic conifer.

    Science.gov (United States)

    Hernandez-Castillo, G R; Rothwell, G W; Mapes, G

    2001-06-01

    A rich fossil biota from a Pennsylvanian age deposit of eastern North America contains numerous vegetative and fertile specimens that conform to a single species of primitive walchian conifers. Among the specimens is a compound pollen cone that comprises closely spaced, helically arranged, leaf-like bracts with axillary dwarf shoots. The specimen looks superficially similar to an ultimate vegetative conifer shoot, but there are small appendages in the axil of each bract that represent the fertile dwarf shoots. Dwarf shoots consist of an axis that bears sterile scales and sporophylls with erect pollen sacs. Pollen found in the sacs is monosaccate and conforms to the sporae dispersae genus Potonieisporites Bhardwaj. This cone is a compound shoot system that is morphologically equivalent to the ovulate cones of conifers and to the pollen cones of Paleozoic cordaitaleans and modern gnetophytes. Therefore, it is fundamentally different from the simple pollen cones of other fossil and modern conifers. Discovery of this specimen unexpectedly supports molecular studies that predict a close relationship between Coniferales and Gnetales, and provides fossil evidence to help reconcile the discordant phylogenetic hypotheses of seed plant systematics that have been developed from morphological and molecular data.

  13. Occupational Allergy to Peach (Prunus persica) Tree Pollen and Potential Cross-Reactivity between Rosaceae Family Pollens.

    Science.gov (United States)

    Jiang, Nannan; Yin, Jia; Mak, Philip; Wen, Liping

    2015-10-01

    Orchard workers in north China are highly exposed to orchard pollens, especially peach and other Rosaceae family pollens during pollination season. The aim of this study was to investigate whether occupational allergy to peach tree pollen as a member of Rosaceae family is IgE-mediated and to evaluate the cross-reactivity among Rosaceae family pollens. Allergen skin test and conjunctival challenge test were performed; enzyme linked immune-sorbent assay (ELISA), inhibiting ELISA, western immunoblotting and inhibiting western immunoblotting were done with Rosaceae family orchard pollens, including peach, apricot, cherry, apple and pear tree pollens. Mass spectrometry was also performed to probe the main allergen component and cross-reactive protein. Sensitizations to peach pollen were found in both skin test and conjunctival challenge in the patients. Serum specific IgE to three pollens (peach, apricot and cherry) were detected through ELISA. When peach pollen used as solid phase, ELISA inhibition revealed other four kinds of pollens capable of inducing partial to strong inhibitions (45% to 87%), with the strongest inhibition belonging to apricot pollen (87%). Western blotting showed predominant IgE binding to a 20 KD protein among these pollens, which appeared to be a cross-reactive allergen component through western blotting inhibition. It was recognized as a protein homologous to glutathione s-transferase 16 from Arabidopsis thaliana. Peach and other Rosaceae family tree pollen may serve as a potential cause of IgE mediated occupational respiratory disease in orchard workers in north China.

  14. Pollen proteomics: from stress physiology to developmental priming.

    Science.gov (United States)

    Chaturvedi, Palak; Ghatak, Arindam; Weckwerth, Wolfram

    2016-06-01

    Pollen development and stress. In angiosperms, pollen or pollen grain (male gametophyte) is a highly reduced two- or three-cell structure which plays a decisive role in plant reproduction. Male gametophyte development takes place in anther locules where diploid sporophytic cells undergo meiotic division followed by two consecutive mitotic processes. A desiccated and metabolically quiescent form of mature pollen is released from the anther which lands on the stigma. Pollen tube growth takes place followed by double fertilization. Apart from its importance in sexual reproduction, pollen is also an interesting model system which integrates fundamental cellular processes like cell division, differentiation, fate determination, polar establishment, cell to cell recognition and communication. Recently, pollen functionality has been studied by multidisciplinary approaches which also include OMICS analyses like transcriptomics, proteomics and metabolomics. Here, we review recent advances in proteomics of pollen development and propose the process of developmental priming playing a key role to guard highly sensitive developmental processes.

  15. [Hypersensitivity to pollen of Olea europea in patients with pollen allergy in Zadar County, Croatia].

    Science.gov (United States)

    Skitarelić, Natasa; Mazzi, Antun; Skitarelić, Neven; Misulić, Josko; Vuletić, Ana

    2010-06-01

    Olive pollen is one of the most common respiratory allergens in the Mediterranean countries. The aim of this study was to establish the frequency of hypersensitivity to the pollen of Olea europea in pollen allergic patients in the County of Zadar. The study included 671 patients with pollen allergy; 61 % were male and 39 % female. 53.5 % were children aged from 4 to 14 years and 46.5 % adolescents and adults from 15 to 59 years. We took their case history, clinically examined them, and tested using the skin prick test and enzymo-immunologic UniCAP test for specific IgE antibodies. For statistical analysis we used the chi-square test. Hypersensitivity to Olea europea pollen was confirmed in 8.8 % patients with pollen allergy. Among them, the most prevalent symptom was rhinitis (58 %). Most hypersensitive patients were urban residents. Only 3 % patients lived on an island. Judging by available data, our findings show the lowest hypersensitivity to olive pollen in the Mediterranean. A comparison with our two earlier studies did not show any fluctuation in this kind of hypersensitivity.

  16. Differential skin test reactivity to pollens in pollen food allergy syndrome versus allergic rhinitis.

    Science.gov (United States)

    Ta, Von; Scott, David R; Chin, William K; Wineinger, Nathan E; Kelso, John M; White, Andrew A

    2015-01-01

    Pollen food allergy syndrome (PFAS), also called oral allergy syndrome, is a form of food allergy in which uncooked foods cause allergic symptoms generally limited to the oral mucosa. It occurs in a subset of patients with pollen allergy, although not all patients have prominent rhinitis symptoms. PFAS is related to antigenic similarity between the pollen and food allergen. The size of skin test reactions in a group of subjects with pollen sensitivity with PFAS was compared with a group of subjects who were pollen sensitive and without PFAS. Self-reported rhinitis symptoms between the two groups were compared to identify if symptom severity differed. Twenty subjects with PFAS and 20 subjects with seasonal allergic rhinitis without PFAS were enrolled in the study. All the subjects underwent standard skin-prick testing to a panel of common allergens, including select fresh fruits and vegetables. The subjects completed a Mini Rhinoconjunctivitis Quality of Life Questionnaire as part of their clinical evaluation. The subjects with PFAS and those without PFAS were compared statistically. The subjects with PFAS had significantly larger-sized skin-prick test results specific to pollens (p allergic rhinitis and PFAS reported milder nasal symptoms in relation to pollen skin test result size when compared with allergic rhinitis controls without PFAS. Our study outlined basic differences between two seemingly similar patient groups with a particularly striking discordance between skin test result sizes and rhinitis symptoms. This discordance should be explored further to increase mechanistic understanding of allergen cross-reactivity in PFAS.

  17. The comparison of pollen abundance in air and honey samples

    OpenAIRE

    Ingrida Šaulienė; Laura Šukienė; Auste Noreikaite-Merkeliene; Vidmantas Pileckas

    2015-01-01

    Honey as a food has long been used in human nutrition and is still popular. Honey is important because of its therapeutic, prophylactic and strengthening value. Pollen is one of the most decisive components that ensure the quality and type of honey. Modern society becomes more and more sensitive to airborne pollen. Therefore, it is crucial to determine the composition of allergenic plant pollen in natural honey. For this purpose, we studied and compared pollen abundance in honey and air sampl...

  18. Forest tree pollen dispersal via the water cycle.

    Science.gov (United States)

    Williams, Claire G

    2013-06-01

    Pine pollen (Pinus spp.), along with other atmospheric particles, is dispersed by the water cycle, but this mode of dispersal requires cloud-pollen interactions that depend on taxon-specific biological properties. In the simplest form of this dispersal, pine pollen ascends vertically to altitudes of 2 to 6 km, where a fraction is captured by mixed-phase cloud formation. Captured pollen accretes into frozen droplets, which ultimately descend as rain, snow, or hail. Whether Pinus pollen can still germinate after its exposure to high-altitude freezing is pertinent to (1) how forests adapt to climate change and (2) potential gene flow between genetically modified plantation species and their conspecific relatives. • To address this question, pollen from four Old World and two New World Pinus species were subjected to immersion freezing, a common cloud formation mode, under laboratory conditions. • Some pollen grains immersed at -20°C for 15, 60, or 120 min in either a dehydrated or a water-saturated state were still capable of germination. After exposure, dehydrated pine pollen had higher germination (43.3%) than water-saturated pollen (7.6%). • Pine pollen exposed to freezing during cloud formation can still germinate, raising the question of whether rain-delivered live pollen might be linked to rain-facilitated pollination. Dispersal of live pine pollen via cloud formation and the water cycle itself deserves closer study.

  19. Diversity and conservation in maize pollen: Phenotypes and transcripts

    Science.gov (United States)

    In addition to its crucial role in seed production, pollen serves as a vector for gene flow between plant populations. Recently, pollen was identified as a mechanism for introduction of transgenes into non-transgenic populations. To investigate the genetic basis for pollen fitn...

  20. Pollen Contents Of Commercial Honeys Of Opi, Nsukka, Enugu ...

    African Journals Online (AJOL)

    Pollen analyses of seven honey samples from Opi-Nsukka Mini market were evaluated for their pollen composition. The results yielded a total of 77 plants belonging to 40 families of flowering plants. Thirty-three plants were identified to the generic level, while thirty-two plants were identified to the specific levels. The pollen ...

  1. Exploring storage protocols for yam ( Dioscorea spp.) pollen ...

    African Journals Online (AJOL)

    Implementation of pollen genebanks allows the conservation of plant genetic resources at the haploid level, pollen genetic manipulations, scheduling of hybrid seed production and improvement of breeding efficiency. To establish pollen storage protocols for various genotypes of West African yams, laboratory experiments ...

  2. Exploring storage protocols for yam (Dioscorea spp.) pollen ...

    African Journals Online (AJOL)

    Jane

    2011-08-08

    Aug 8, 2011 ... Implementation of pollen genebanks allows the conservation of plant genetic resources at the haploid level, pollen genetic manipulations, scheduling of hybrid seed production and improvement of breeding efficiency. To establish pollen storage protocols for various genotypes of West African yams, ...

  3. Pollen loncevity in ecologically different zones of Western Kenya ...

    African Journals Online (AJOL)

    The survival of pollen after dehiscence is an important factor affecting the geneflow. Studies were conducted to investigate the duration of pollen viability in two locations in western Kenya - Eldoret and Kakamega, representing the highland tropical and moist mid-altitude/transitional zones, respectively. Pollen was collected ...

  4. Saccharomyces cerevisiae Fermentation Effects on Pollen: Archaeological Implications

    Directory of Open Access Journals (Sweden)

    Crystal A. Dozier

    2016-03-01

    Full Text Available Pollen is the reproductive agent of flowering plants; palynology is utilized by archaeologists because sporopollenin, a major component in the exine of pollen grains, is resistant to decay and morphologically distinctive. Wine, beer, and mead have been identified in the archaeological record by palynological assessment due to indicator species or due to a pollen profile similar to that recovered from honey, a common source of sugar in a variety of fermented beverages. While most palynologists have assumed that pollen grains are resistant to alcoholic fermentation, a recent study in food science implies that pollen is a yeast nutrient because pollen-enriched meads produce more alcohol. The experiment presented here explores the potential distortion of the pollen record through fermentation by brewing a traditional, pollen-rich mead with Saccharomyces cerevisiae. In this experiment, the pollen grains did not undergo any discernible morphological changes nor were distorted in the pollen profile. Any nutrition that the yeast garners from the pollen therefore leaves sporopollenin intact. These results support palynological research on residues of alcoholic beverages and confirms that the fermentation process does not distort the pollen profile of the original substance. The paper concludes with the potential and limits of palynological study to assess fermentation within the archaeological record.

  5. Aerodynamics of saccate pollen and its implications for wind pollination.

    Science.gov (United States)

    Schwendemann, Andrew B; Wang, George; Mertz, Meredith L; McWilliams, Ryan T; Thatcher, Scott L; Osborn, Jeffrey M

    2007-08-01

    Pollen grains of many wind-pollinated plants contain 1-3 air-filled bladders, or sacci. Sacci are thought to help orient the pollen grain in the pollination droplet. Sacci also increase surface area of the pollen grain, yet add minimal mass, thereby increasing dispersal distance; however, this aerodynamic hypothesis has not been tested in a published study. Using scanning electron and transmission electron microscopy, mathematical modeling, and the saccate pollen of three extant conifers with structurally different pollen grains (Pinus, Falcatifolium, Dacrydium), we developed a computational model to investigate pollen flight. The model calculates terminal settling velocity based on structural characters of the pollen grain, including lengths, widths, and depths of the main body and sacci; angle of saccus rotation; and thicknesses of the saccus wall, endoreticulations, intine, and exine. The settling speeds predicted by the model were empirically validated by stroboscopic photography. This study is the first to quantitatively demonstrate the adaptive significance of sacci for the aerodynamics of wind pollination. Modeling pollen both with and without sacci indicated that sacci can reduce pollen settling speeds, thereby increasing dispersal distance, with the exception of pollen grains having robust endoreticulations and those with thick saccus walls. Furthermore, because the mathematical model is based on structural characters and error propagation methods show that the model yields valid results when sample sizes are small, the flight dynamics of fossil pollen can be investigated. Several fossils were studied, including bisaccate (Pinus, Pteruchus, Caytonanthus), monosaccate (Gothania), and nonsaccate (Monoletes) pollen types.

  6. The relationship of storage and viability of Lily pollen

    NARCIS (Netherlands)

    Rhee, H.K.; Lim, Jin Hee; Cho, Hae Ryong; Tuyl, van J.M.

    2003-01-01

    The study was conducted to estimate the pollen viability of eight lily genotypes and optimum storage conditions. Pollen viability was assessed by in vitro germination, FCR (Fluorochromatic raction) test and fruit set test. Pollen grains were stored in the dark chamber where the temperature was

  7. Identification of two highly specific pollen promoters using transcriptomic data.

    Science.gov (United States)

    Muñoz-Strale, Daniela; León, Gabriel

    2014-10-01

    The mature pollen grain displays a highly specialized function in angiosperms. Accordingly, the male gametophyte development involves many specific biological activities, making it a complex and unique process in plants. In order to accomplish this, during pollen development, a massive transcriptomic remodeling takes place, indicating the switch from a sporophytic to a gametophytic program and involving the expression of many pollen specific genes. Using microarray databases we selected genes showing pollen-specific accumulation of their mRNAs and confirmed this through RT-PCR. We selected five genes (POLLEN SPECIFIC GENE1-5) to investigate the pollen specificity of their expression. Transcriptional fusions between the putative promoters of these genes and the uidA reporter gene in Arabidopsis confirmed the pollen specific expression for at least two of these genes. The expression of the cytotoxin Barnase controlled by these promoters generated pollen specific ablation and male sterility. Through the selection of pollen specific genes from public datasets, we were able to identify promoter regions that confer pollen expression. The use of the cytotoxin Barnase allowed us to demonstrate its expression is exclusively limited to the pollen. These new promoters provide a powerful tool for the expression of genes exclusively in pollen. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Late Holocene Changes in Vegetation of the Mrągowo Lakeland (NE Poland as Registered in the Pollen Record from Lake Salęt

    Directory of Open Access Journals (Sweden)

    Szal Marta

    2014-04-01

    Full Text Available Pollen analysis of sediments from the upper part of bottom deposits from Lake Salęt allowed reconstruction of main stages of the Late Holocene vegetation transformation in the Mrągowo Lake District (from ca. 3600 cal. years BC and to correlate some of these changes with immigration and economic activity of local human groups. Significant spreading of secondary semi-natural birch forest, development of horn beam forest and increasing importance of anthropogenic open communities were the most characteristic features of vegetation evolution. A definite break down of elm took place between 2900 and 2500 cal. years BC, slightly after increased contribution of birch in wood lands. Disappearance of hazel around 1200 cal. years BC, accompanied by expansion of horn beam has been observed and should be linked with activity of the Ząbie-Szestno type culture and the Lusatian culture tribes during the Bronze Age, but not with a climate change. Considerable intensification of settlement processes recorded in the younger part of the Subatlantic chronozone was one of the important reasons that were responsible for quick changes in forest structure. Strong and continued deforestation started as early as the end of the 10th century AD and was substantially intensified in the first half of the 13th century.

  9. Climate warming and the decline of Taxus airborne pollen in urban pollen rain (Emilia Romagna, northern Italy).

    Science.gov (United States)

    Mercuri, A M; Torri, P; Casini, E; Olmi, L

    2013-01-01

    Woody plant performance in a changing global environment has always been at the centre of palaeoenvironmental and long-term climate reconstructions carried out by means of pollen analysis. In Mediterranean regions, Taxus constitutes the highest percentage in past pollen diagrams from cold or cool periods, and therefore it is generally considered a good index to infer climate features from past records. However, a comparison of these inferences with the true current trends in pollen production has not been attemped until now. This study reports the decline of airborne pollen of Taxus observed in Emilia Romagna, a region of northern Italy, during the period 1990-2007. Phenological observations on four male specimens and microscopic examination of fresh pollen were made in order to check Taxus flowering time and pollen morphology. Airborne pollen was monitored through continuous sampling with a Hirst volumetric sampler. In the 18-year long period of investigation, Taxus pollen production has decreased, while total woody pollen abundance in air has increased. The trend of the Taxus pollen season shows a delay at the beginning, a shortening of the pollen period, and an advance of the end of the pollen season. This was interpreted as a response to climate warming. In particular, Taxus follows the behaviour of winter-flowering plants, and therefore earlier pollination is favoured at low autumn temperatures, while late pollination occurs more often, most likely after warm autumn temperatures. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. Recent pollen spectra from the deciduous and coniferous-deciduous forests of Northeastern Minnesota: a study in pollen dispersal

    NARCIS (Netherlands)

    Janssen, C.R.

    1966-01-01

    Pollen samples were taken along nine transects across local vegetational belts bordering bogs or ponds in overall deciduous and coniferous-deciduous forest regions. Three types of pollen rain are distinguished: local, extralocal, and regional. Local pollen rain is derived from plants that grow at or

  11. [Identification of airborne pollen and airborne particles with pollen allergen (Cry j 1, Dac g) by aeroallergen immunoblotting technique].

    Science.gov (United States)

    Takahashi, Yuichi; Nagoya, Takao; Ohta, Nobuo

    2002-08-01

    After collection of airborne particles with a seven-day recording volumetric spore trap (Burkard model) using optically clear, pressure sensitive acrylic adhesive tapes, a dry PVDF membrane was pressed down firmly onto the adhesive tape, antigen-antibody reaction was performed in full contact with the tapes and PVDF membrane. Dark purple spots from airborne pollen allergens were examined under a light microscope to evaluate the form of pollens and particles wit h the antigenicity. It is clarified that identification of the form of pollens with the antigencity is possible not only pollens with the antigenicity but a pollen has already lost its shape, and it is also clarified that some airborne particular matters have the pollen antigencity. Airborne samples were collected during the Cryptomeria japonica or grass pollen season. Samples collected during the C. japonica pollen season were treated with anti-Cry j 1 monoclonal antibody, and those during the grass pollen season with anti-Dac g rabbit IgG. Samples collected during the C. japonica and the grass pollen peak season were treated with antibodies from sera of pollinosis patients. Spots originated not only from relevant pollen grains but also from parts of airborne particular matter have the pollen antigenicity and some spots could not observed for any kind of particles.

  12. Pollen morphology of the dichapetalaceae with special reference to evolutionary trends and mutual relationships of pollen types

    NARCIS (Netherlands)

    Punt, W.

    Pollen grains of all three genera of Dichapetalaceae (Dichapetalum, Stephanopodium and Tapura) comprising about 150 species have been studied. Twenty-nine pollen types were recognized and the family has to be considered eurypalynous. A key to the pollen types is added. Based on evolutionary trends

  13. Effects of three irradiation methods on pollen germination and pollen tube growth of Pinus thunbegii

    International Nuclear Information System (INIS)

    Li Guoping; Yang Lusheng; Chen Suying; Huang Zhiming; Hu Wenying

    2008-01-01

    The effect of 30 keV nitrogen ion beams, UV and γ-rays irradiation on pollen germination and pollen tube growth of Pinus thunbergii were investigated. Results showed that the biological effects induced by ion beam implantation were different from those induced by UV and γ-rays irradiation. The dose response curve of ion implantation treatment presented a particular 'saddle-likepattern, and ion implantation also significantly induced pollen tube tip swelling. These results indicated that low energy ion implantation might work in different way compared to UV and γ-rays irradiation. It was suggested that pollen could be served as an excellent model system to study the underlying mechanisms responsible for biological effects of ion beam irradiation at cellular level. (authors)

  14. Inherent optical properties of pollen particles: a case study for the morning glory pollen.

    Science.gov (United States)

    Liu, Chao; Yin, Yan

    2016-01-25

    Biological aerosols, such as bacteria, fungal spores, and pollens, play an important role on various atmospheric processes, whereas their inherent optical property is one of the most uncertainties that limit our ability to assess their effects on weather and climate. A numerical model with core-shell structure, hexagonal grids and barbs is developed to represent one kind of realistic pollen particles, and their inherent optical properties are simulated using a pseudo-spectral time domain method. Both the hexagonal grids and barbs substantially affect the modeled pollen optical properties. Results based on the realistic particle model are compared with two equivalent spherical approximations, and the significant differences indicate the importance of considering pollen geometries for their optical properties.

  15. Pollen calendar of the city of Salamanca (Spain). Aeropalynological analysis for 1981-1982 and 1991-1992.

    Science.gov (United States)

    Hernández Prieto, M; Lorente Toledano, F; Romo Cortina, A; Dávila González, I; Laffond Yges, E; Calvo Bullón, A

    1998-01-01

    We report a study on the contents of airborne pollen in the city of Salamanca (Spain) aimed at establishing a pollen calendar for the city for the yearly periods of maximum concentrations, relating these with quantifiable atmospheric variables over two two-year periods with an interval of 10 years between them: 1981-82 and 1991-92. The pollen was captured with Burkard spore-traps, based on Hirst's volumetric method. Determinations were made daily and were used to make preparations, previously stained with basic fuscin, for study under light microscopy at x 1,000 magnification. 946 preparations were analyzed, corresponding to the same number of days distributed over 150 weeks of the periods studied. The results afforded the identification of 48 different types of pollen grain: Grasses (Poaceae), Olea europea (olive), Quercus rotundifolia (Holm-oak), other Quercus spp. (Q. pyrenaica, Q. suber, Q. faginea, etc.), Cupressaceae (Cupressus sempervivens, C. arizonica, Juniperus communis etc.), Plantago (Plantago lanceolata, Plantago media, etc.), Pinaceae (Pinus communis, Abies alba, etc.), Rumex sp. (osier), Urtica dioica (nettle), Parietaria (Parietaria officinalis, P. judaica), Chenopodio-Amaranthaceae (Chenopodium sp., Amaranthus sp., Salsola kali, etc.), Artemisia vulgaris (Artemisia), other Compositae (Taraxacum officinalis, Hellianthus sp. etc.), Castanea sativa (Chestnut), Ligustrum sp. (privet), Betula sp. (birch), Alnus sp. (common alder), Fraxinus sp (ash), Populus sp. (poplar), Salix sp. (willow), Ulmus sp. (elm), Platanus sp. (plantain, plane), Carex sp. (sweet flag), Erica sp. (common heather), Leguminosae or Fabaceae:--Papillionaceae (Medicago sp.; Cercis sp., Robina sp.)--Cesalpinoideae Acacia sp. (Acacia),--Mimosoideae: Sophora japonica, Umbelliferae (Foeniculum sp., Cirsium sp., etc.), Centaurea sp., Cistus sp. (rock rose), Typha sp (bulrush), Mirtaceae (Myrtus communis), Juglans regia (Walnut), Galium verum, Filipendula sp. (spirea/drop wort), Rosaceae

  16. Non pollen palynomorphs in pollen slides: their determination and utilization in palaeoecology

    Czech Academy of Sciences Publication Activity Database

    Jankovská, Vlasta

    2008-01-01

    Roč. 48, supp.10-11 (2008), s. 488-490 ISSN 1068-7971. [Micropalaeontology: palaeobiological and geological aspects. Novosibirsk, 25.09.2008-27.09.2008] R&D Projects: GA ČR(CZ) GA205/06/0587 Institutional research plan: CEZ:AV0Z60050516 Keywords : Non pollen palynomorphs * pollen slides * palaeoreconstruction Subject RIV: EF - Botanics Impact factor: 0.850, year: 2008

  17. Extensive pollen flow but few pollen donors and high reproductive variance in an extremely fragmented landscape.

    Directory of Open Access Journals (Sweden)

    Rafael G Albaladejo

    Full Text Available Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (N(ep and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73-93%, fat-tailed dispersal kernels and large average pollination distances (δ = 229-412 m. However, they also agreed in detecting very few pollen donors (N(ep = 4.3-10.2 and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plants and 5.5% of males were responsible for 50% of pollinations. Although we did not find reduced levels of genetic diversity, the adult population showed high levels of biparental inbreeding (14% and strong spatial genetic structure (S(p = 0.012, probably due to restricted seed dispersal and scarce safe sites for recruitment. Overall, limited seed dispersal and the scarcity of successful pollen donors can be contributing to generate local pedigrees and to increase inbreeding, the prelude of genetic impoverishment.

  18. Extensive pollen flow but few pollen donors and high reproductive variance in an extremely fragmented landscape.

    Science.gov (United States)

    Albaladejo, Rafael G; Guzmán, Beatriz; González-Martínez, Santiago C; Aparicio, Abelardo

    2012-01-01

    Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (N(ep)) and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73-93%), fat-tailed dispersal kernels and large average pollination distances (δ = 229-412 m). However, they also agreed in detecting very few pollen donors (N(ep) = 4.3-10.2) and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plants and 5.5% of males were responsible for 50% of pollinations. Although we did not find reduced levels of genetic diversity, the adult population showed high levels of biparental inbreeding (14%) and strong spatial genetic structure (S(p) = 0.012), probably due to restricted seed dispersal and scarce safe sites for recruitment. Overall, limited seed dispersal and the scarcity of successful pollen donors can be contributing to generate local pedigrees and to increase inbreeding, the prelude of genetic impoverishment.

  19. Comprehensive Transcriptome Analysis of Response to Nickel Stress in White Birch (Betula papyrifera.

    Directory of Open Access Journals (Sweden)

    Gabriel Theriault

    Full Text Available White birch (Betula papyrifera is a dominant tree species of the Boreal Forest. Recent studies have shown that it is fairly resistant to heavy metal contamination, specifically to nickel. Knowledge of regulation of genes associated with metal resistance in higher plants is very sketchy. Availability and annotation of the dwarf birch (B. nana enables the use of high throughout sequencing approaches to understanding responses to environmental challenges in other Betula species such as B. papyrifera. The main objectives of this study are to 1 develop and characterize the B. papyrifera transcriptome, 2 assess gene expression dynamics of B. papyrifera in response to nickel stress, and 3 describe gene function based on ontology. Nickel resistant and susceptible genotypes were selected and used for transcriptome analysis. A total of 208,058 trinity genes were identified and were assembled to 275,545 total trinity transcripts. The transcripts were mapped to protein sequences and based on best match; we annotated the B. papyrifera genes and assigned gene ontology. In total, 215,700 transcripts were annotated and were compared to the published B. nana genome. Overall, a genomic match for 61% transcripts with the reference genome was found. Expression profiles were generated and 62,587 genes were found to be significantly differentially expressed among the nickel resistant, susceptible, and untreated libraries. The main nickel resistance mechanism in B. papyrifera is a downregulation of genes associated with translation (in ribosome, binding, and transporter activities. Five candidate genes associated to nickel resistance were identified. They include Glutathione S-transferase, thioredoxin family protein, putative transmembrane protein and two Nramp transporters. These genes could be useful for genetic engineering of birch trees.

  20. Post-treatment efficacy of discontinuous treatment with 300IR 5-grass pollen sublingual tablet in adults with grass pollen-induced allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Didier, A; Malling, H-J; Worm, Marcel

    2013-01-01

    Sustained efficacy over three pollen seasons of pre- and co-seasonal treatment with 300IR 5-grass pollen sublingual tablet has been demonstrated in adults with moderate-severe grass pollen-associated allergic rhinoconjunctivitis....

  1. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 3. Pollen Grains, Random Walks and Einstein. Sriram Ramaswamy. General Article Volume 5 Issue 3 March 2000 pp 16-34. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/005/03/0016-0034 ...

  2. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 12. Pollen Grains, Random Walks and Einstein. Sriram Ramaswamy. Volume 10 Issue 12 December 2005 pp 106-124. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/010/12/0106-0124 ...

  3. Changes to airborne pollen counts across Europe.

    Directory of Open Access Journals (Sweden)

    Chiara Ziello

    Full Text Available A progressive global increase in the burden of allergic diseases has affected the industrialized world over the last half century and has been reported in the literature. The clinical evidence reveals a general increase in both incidence and prevalence of respiratory diseases, such as allergic rhinitis (common hay fever and asthma. Such phenomena may be related not only to air pollution and changes in lifestyle, but also to an actual increase in airborne quantities of allergenic pollen. Experimental enhancements of carbon dioxide (CO[Formula: see text] have demonstrated changes in pollen amount and allergenicity, but this has rarely been shown in the wider environment. The present analysis of a continental-scale pollen data set reveals an increasing trend in the yearly amount of airborne pollen for many taxa in Europe, which is more pronounced in urban than semi-rural/rural areas. Climate change may contribute to these changes, however increased temperatures do not appear to be a major influencing factor. Instead, we suggest the anthropogenic rise of atmospheric CO[Formula: see text] levels may be influential.

  4. Grass Pollen Pollution from Biofuels Farming

    Czech Academy of Sciences Publication Activity Database

    Ratajová, A.; Tříska, Jan; Vrchotová, Naděžda; Kolář, L.; Kužel, S.

    2013-01-01

    Roč. 26, č. 4 (2013), s. 199-203 ISSN 2151-321X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : grass pollen pollution * biofuel s farming * temperate climate * PK-fertilization * N-fertilization * phenolic Subject RIV: EH - Ecology, Behaviour Impact factor: 0.556, year: 2013

  5. Stress as a Trigger of Pollen Embryogenesis

    Czech Academy of Sciences Publication Activity Database

    Žárský, Viktor; Soukupová, H.

    2000-01-01

    Roč. 27, č. 5 (2000), s. 411-413 ISSN 1015-5880 R&D Projects: GA AV ČR IAA5038907; GA ČR GA206/99/1138 Institutional research plan: CEZ:AV0Z5038910 Keywords : Heat shock proteins * pollen embryogenesis * stress Subject RIV: EB - Genetics ; Molecular Biology

  6. Lipids in pollen - They are different.

    Science.gov (United States)

    Ischebeck, Till

    2016-09-01

    During evolution, the male gametophyte of Angiosperms has been severely reduced to the pollen grain, consisting of a vegetative cell containing two sperm cells. This vegetative cell has to deliver the sperm cells from the stigma through the style to the ovule. It does so by producing a pollen tube and elongating it to many centimeters in length in some species, requiring vast amounts of fatty acid and membrane lipid synthesis. In order to optimize this polar tip growth, a unique lipid composition in the pollen has evolved. Pollen tubes produce extraplastidial galactolipids and store triacylglycerols in lipid droplets, probably needed as precursors of glycerolipids or for acyl editing. They also possess special sterol and sphingolipid moieties that might together form microdomains in the membranes. The individual lipid classes, the proteins involved in their synthesis as well as the corresponding Arabidopsis knockout mutant phenotypes are discussed in this review. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. The morphology of pollen presenter and polymorphism of pollen grains Taraxacum officinale F. H. Wigg.

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The study of the structure of the pollen presenter of Taraxacum officinale and morphology of pollen grains was conducted based on plant material sampled from three different sites. One of them was a forest meadow situated away from the city, and the other two were located in the city centre of Lublin. Light and electron scanning microscopy were used in the study. The pollen presenter in Taraxacum officinale occurs at the upper part of the style situated over the androecium and on the outer part of the stigma. Numerous unicellular trichomes are found on the entire surface of the epidermis of the presenter. The function of the presenter consists in transferring pollen grains above the androecium and corolla petals. Its activity does not stop after pollen release from anthers. Taraxacum pollen grains represent the Crepis - type. Most frequently, they are tricolporate, radially symmetric and isopolar. In terms of the size, they are included in medium-sized grains. In the material examined, many deformed and asymmetric grains were observed, though they were marked by high viability at the level of 96.5-99%. Grains with the largest average lengths of the equatorial and polar axes were found in plants sampled from the meadow situated out of town. In the plant material from all sites, grains with disturbances of the external structure occurred.

  8. In vitro pollen germination and pollen viability in passion fruit (Passiflora spp.

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2013-12-01

    Full Text Available The use of Passiflora species for ornamental purposes has been recently developed, but little is known about pollen viability and the potential for crossing different species. The objective of this study was to evaluate the pollen viability of six Passiflora species collected from different physiological stages of development through in vitro germination and histochemical analysis using dyes. The pollen was collected in three stages (pre-anthesis, anthesis and post-anthesis. Three compositions of culture medium were used to evaluate the in vitro germination, and two dyes (2,3,5-triphenyltetrazolium chloride, or TTC, and Lugol's solution were used for the histochemical analysis. The culture medium containing 0.03% Ca(NO3 4H2O, 0.02% of Mg(SO4 .7H2O, 0.01% of KNO3, 0,01% of H3BO3, 15% sucrose, and 0.8% agar, pH 7.0, showed a higher percentage of pollen grains germinated. Anthesis is the best time to collect pollen because it promotes high viability and germination. The Lugol's solution and TTC dye overestimated the viability of pollen, as all accessions showed high viability indices when compared with the results obtained in vitro.

  9. Evaluation of Holocene pollen records from the Romanian Plain.

    Science.gov (United States)

    Tomescu

    2000-05-01

    This study is a critical review of pollen analyses carried out on Holocene sequences from 15 sites in and near the Romanian Plain. Three sites come from natural sediments, 10 sites are from anthropogenic deposits and two are from both anthropogenic and natural settings. The general reconstruction is of a steppe-forest-steppe vegetation through the Holocene. The nature of the deposits, however, casts doubts on this reconstruction. Deposits of archaeological sites generally yield pollen spectra that are influenced by human activities and thus unsuitable for vegetation reconstructions. Loess deposits are also unfavorable for pollen preservation because of high pH and porosity. Consequently, pollen spectra from loess deposits are strongly biased by selective pollen destruction. Research and experiments carried out by several authors suggest that spectra dominated by Asteraceae, Poaceae, Chenopodiaceae or Pinus pollen in soils and loess are a result of selective pollen destruction, especially if low pollen concentrations, progressive pollen deterioration or high frequencies of deteriorated or unidentifiable pollen are evidenced. The fact that pollen records from the Romanian Plain come from loess, alkaline peat or archaeological sites reduces their reliability for reconstructions of vegetation. The vegetation history of similar regions in Hungary, Bulgaria and Turkey suggests that early Holocene steppe vegetation was gradually replaced by forest or forest-steppe vegetation in the late Holocene. Records from lake sediments are required to find out whether the Holocene vegetation history of the Romanian Plain was similar.

  10. Pollen Processing Behavior of Heliconius Butterflies: A Derived Grooming Behavior

    Science.gov (United States)

    Hikl, Anna-Laetitia; Krenn, Harald W.

    2011-01-01

    Pollen feeding behaviors Heliconius and Laparus (Lepidoptera: Nymphalidae) represent a key innovation that has shaped other life history traits of these neotropical butterflies. Although all flower visiting Lepidoptera regularly come in contact with pollen, only Heliconius and Laparus butterflies actively collect pollen with the proboscis and subsequently take up nutrients from the pollen grains. This study focused on the behavior of pollen processing and compared the movement patterns with proboscis grooming behavior in various nymphalid butterflies using video analysis. The proboscis movements of pollen processing behavior consisted of a lengthy series of repeated coiling and uncoiling movements in a loosely coiled proboscis position combined with up and down movements and the release of saliva. The proboscis-grooming behavior was triggered by contamination of the proboscis in both pollen feeding and non-pollen feeding nymphalid butterflies. Proboscis grooming movements included interrupted series of coiling and uncoiling movements, characteristic sideways movements, proboscis lifting, and occasionally full extension of the proboscis. Discharge of saliva was more pronounced in pollen feeding species than in non-pollen feeding butterfly species. We conclude that the pollen processing behavior of Heliconius and Laparus is a modified proboscis grooming behavior that originally served to clean the proboscis after contamination with particles. PMID:22208893

  11. The importance of cross-reactivity in grass pollen allergy

    Directory of Open Access Journals (Sweden)

    Aleksić Ivana

    2014-01-01

    Full Text Available According to the data obtained from in vivo and in vitro testing in Serbia, a significant number of patients have allergic symptoms caused by grass pollen. We examined the protein composition of grass pollens (Dactylis glomerata, Lolium perenne and Phleum pratense and cross-reactivity in patients allergic to grass pollen from our region. The grass pollen allergen extract was characterized by SDS-PAGE, while cross-reactivity of single grass pollens was revealed by immunoblot analysis. A high degree of cross-reactivity was demonstrated for all three single pollens in the sera of allergic patients compared to the grass pollen extract mixture. Confirmation of the existence of cross-reactivity between different antigenic sources facilitates the use of monovalent vaccines, which are easier to standardize and at the same time prevent further sensitization of patients and reduces adverse reactions. [Projekat Ministarstva nauke Republike Srbije, br. 172049 i br. 172024

  12. Pollen features of hazelnut (Corylus avellana L. from different habitats

    Directory of Open Access Journals (Sweden)

    Natalia Nikolaieva

    2014-04-01

    Full Text Available The aim of this work was to study general morphological characteristics of pollen grains of Corylus avellana L. Seven samples of pollen were investigated. Samples were collected from different habitats in Ukraine – from botanical gardens (Kyiv, Kamianets-Podilskyi and natural habitats (Kyiv region, Kamianets-Podilskyi, and Sumy region. We studied such morphological traits of pollen grains as length of polar and equatorial axes, diameter of pores, and shape of the pollen grain (elongation index. Analysis of morphological characters of pollen was carried out using electron microscope. Comparison of data was performed with the data of the base polleninfo.org. During research the differences in these parameters were marked. Pollen grains of C. avellana are generally isopolar, from suboblate to oblate or oblate-spheroidal, and contain 3 pores. The article contains an attempt to explain the size variations noted for the pollen collected from different habitats.

  13. Monitoring, modelling and forecasting of the pollen season

    DEFF Research Database (Denmark)

    Scheifinger, Helfried; Belmonte, Jordina; Buters, Jeroen

    2013-01-01

    The section about monitoring covers the development of phenological networks, remote sensing of the season cycle of the vegetation, the emergence of the science of aerobiology and, more specifically, aeropalynology, pollen sampling instruments, pollen counting techniques, applications...... of aeropalynology in agriculture and the European Pollen Information System. Three data sources are directly related with aeropalynology: phenological observations, pollen counts and remote sensing of the vegetation activity. The main future challenge is the assimilation of these data streams into numerical pollen...... forecast systems. Over the last decades consistent monitoring efforts of various national networks have created a wealth of pollen concentration time series. These constitute a nearly untouched treasure, which is still to be exploited to investigate questions concerning pollen emission, transport...

  14. Exceptional preservation of Miocene pollen: plasmolysis captured in salt?

    Energy Technology Data Exchange (ETDEWEB)

    Durska, W.

    2016-07-01

    Exceptionally well-preserved Miocene pollen from the Bochnia salt mine of southern Poland is reported herein. The halite deposits within the salt mine belonging to Late Badenian (Miocene) marine evaporites originated in the Paratethys. Rounded and angular structures are present inside pollen grains. On the basis of the similarity with plasmolyzed pollen grains of modern plants, these structures are considered to represent cytoplasms plasmolyzed in the condensed brine prior to fossilization. Two forms of plasmolyzed cytoplasms (concave and convex) can be observed in modern pollen. Both are distinguished in the investigated fossil material. In porate and colporate grains the shape of the plasmolyzed cellular content is concave while in inaperturate it is convex. The plasmolysis form depends on the type of apertures and pollen shape. The percentage of pollen with fossilized cytoplasms within individual taxa is a valuable environmental indicator, as it depends on the proximity of the pollen-producing plant assemblages to the depositional setting. (Author)

  15. Ultrastructure of Withania Somnifera (L.) Dunal pollen grains

    International Nuclear Information System (INIS)

    Alwadie, H.M.

    2002-01-01

    Light, scanning and transmission electron microscopy were used to study the morphology and ultrastructure of Withania Somnifera (L.) Dunall pollen grains. Light microscopic examination revealed that the pollen grains are tri- or tetrazonocoplate grains, approximately as long as broad, measuring 29-um. Scanning electron microscopic observation showed that surface sculpturing of the pollen is scarbate-granulate. Ultrathin sections as examined by transmission electron microscope showed that the pollen contained numerous starch grains, lipid droplets, endoplasmic reticulum and vesicles of dictyosomes. Two layers of the pollen wall were also distinguished, the outer wall (exine) divided into ektexine and endexine as well as the inner layer (intine). The nutritive values of Withania pollen are discussed. The importance of studying the ultrastructure of pollen grains as a new tool in palynology is also discussed. (author)

  16. Super earth interiors and validity of Birch's Law for ultra-high pressure metals and ionic solids

    Science.gov (United States)

    Ware, Lucas Andrew

    2015-01-01

    Super Earths, recently detected by the Kepler Mission, expand the ensemble of known terrestrial planets beyond our Solar System's limited group. Birch's Law and velocity-density systematics have been crucial in constraining our knowledge of the composition of Earth's mantle and core. Recently published static diamond anvil cell experimental measurements of sound velocities in iron, a key deep element in most super Earth models, are inconsistent with each other with regard to the validity of Birch's Law. We examine the range of validity of Birch's Law for several metallic elements, including iron, and ionic solids shocked with a two-stage light gas gun into the ultra-high pressure, temperature fluid state and make comparisons to the recent static data.

  17. Diagnostic value of scratch-chamber test, skin prick test, histamine release and specific IgE in birch-allergic patients with oral allergy syndrome to apple

    DEFF Research Database (Denmark)

    Osterballe, M; Scheller, R; Stahl Skov, P

    2003-01-01

    BACKGROUND: The aim of the study was to examine the diagnostic value of skin prick test (SPT), scratch-chamber test (SCT), histamine release (HR) and specific immunoglobulin E (IgE) in birch-allergic patients with oral allergy syndrome to apple. METHODS: Ten birch-allergic patients with oral...

  18. PollenCALC: Software for estimation of pollen compatibility of self-incompatible allo- and autotetraploid species

    DEFF Research Database (Denmark)

    Aguirre, Andrea A; Wollenweber, Bernd; Frei, Ursula K

    2012-01-01

    available for predicting pollen haplotype frequencies and pollen compatibility in tetraploid species. Results PollenCALC is a software tool written in C++ programming language that can predict pollen compatibility percentages for polyploid species with a two-locus (S, Z) self-incompatibility system....... The program predicts pollen genotypes and frequencies based on defined meiotic parameters for allo- or autotetraploid species with a gametophytic S-Z SI system. These predictions can be used to obtain expected values for for diploid and for (allo- or autotetraploidy SI grasses. Conclusion The information...

  19. Repeated evolution of tricellular (and bicellular) pollen.

    Science.gov (United States)

    Williams, Joseph H; Taylor, Mackenzie L; O'Meara, Brian C

    2014-04-01

    Male gametophytes of seed plants are sexually immature at the time they are dispersed as pollen, but approximately 30% of flowering plants have tricellular pollen containing fully formed sperm at anthesis. The classic study of Brewbaker (1967: American Journal of Botany 54: 1069-1083) provided a powerful confirmation of the long-standing hypothesis that tricellular pollen had many parallel and irreversible origins within angiosperms. We readdressed the main questions of that study with modern comparative phylogenetic methods. We used our own and more recent reports to greatly expand the Brewbaker data set. We modeled trait evolution for 2511 species on a time-calibrated angiosperm phylogeny using (1) Binary State Speciation and Extinction (BiSSE), which accounts for the effect of species diversification rates on character transition rates and, (2) the hidden rates model (HRM), which incorporates variation in transition rates across a phylogeny. Seventy percent of species had bicellular pollen. BiSSE found a 1.9-fold higher bicellular to tricellular transition rate than in the reverse direction, and bicellular lineages had a 1.8-fold higher diversification rate than tricellular lineages. HRM found heterogeneity in evolutionary rates, with bidirectional transition rates in three of four rate classes. The tricellular condition is not irreversible. Pollen cell numbers are maintained at intermediate frequencies because lower net diversification rates of tricellular lineages are counterbalanced by slower state shifts to the bicellular condition. That tricellular lineages diversify slowly and give rise to bicellular lineages slowly reflects a linkage between the evolution of sporophyte lifestyles and the developmental lability of male gametophytes.

  20. Pollen sources in the Bojanów forest complex identified on honeybee pollen load by microscopic analysis

    Directory of Open Access Journals (Sweden)

    Ernest Stawiarz

    2017-11-01

    Full Text Available The aim of this study was to determine sources of pollen for the honeybee in the Bojanów forest complex, Nowa Dęba Forest District (southeastern Poland. Sampling of pollen loads from bees extended from the beginning of May until the end of September 2016 and was carried out at 7-day intervals using pollen traps mounted at the entrance of beehives. A total of 73 pollen load samples were collected from the study area. Fifty-nine taxa from 31 plant families were identified in the analyzed material. From 4 to 21 taxa (average 9.5 were recorded in one sample. The pollen of Brassicaceae (“others”, Taraxacum type, Solidago type, and Rumex had the highest frequency in the pollen loads examined. Apart from these four taxa, pollen grains of Rubus type, Poaceae (“others”, Calluna, Fagopyrum, Trifolium repens s. l., Phacelia, Aster type, Melampyrum, Quercus, Cornus, and Veronica were recorded in the dominant pollen group. The forest habitat taxa that provided pollen rewards to honeybees in the Bojanów forest complex were the following: Rubus, Calluna, Prunus, Tilia, Frangula alnus, Pinus, Quercus, Cornus, Robinia pseudoacacia, Salix, and Vaccinium. Apart from forest vegetation, the species from meadows and wastelands adjacent to this forest complex, represented by Taraxacum, Rumex, Plantago, Poaceae, Trifolium repens, and Solidago, proved to be an important source of pollen. The study indicates that forest communities are a valuable source of pollen for pollinating insects from early spring through to late fall.

  1. Lilium spp. pollen in China (Liliaceae: taxonomic and phylogenetic implications and pollen evolution related to environmental conditions.

    Directory of Open Access Journals (Sweden)

    Yun-peng Du

    Full Text Available Recent molecular and karyologic studies have significantly modified delimitation of Lilium. However, despite the importance of pollen evolution in the genus comprehensive studies with electron microscopy and evaluation of pollen evolution are lacking. Therefore, we studied pollen morphology in a sample of 65 individuals from 37 taxa covering all the sections distributed in the world, using scanning electron microscopy. Our collection of 49 individuals from 21 taxa covering all five sections in China was also included in the database. We found pollen tetrads in L. bakerianum. Based on present and previous studies, our results suggest that pollen from L. formosanum should be classified as a new type, Formosanum. Combined with morphological and molecular evidence, pollen sculpture patterns appear to reflect phylogenetic relationships and are useful for species or subsection delimitation. Based on a comprehensive survey and correlation with potential functional implications, we propose the following hypothesis: evolution of an exine sculpture shows pollen type trends from Martagon → Callose → Concolor → Formosanum. The evolutionary trend regarding pollen sculpture and size could be related to selective pressure to adapt to environmental conditions. Pollen size and shape showed a significantly positive correlation with annual precipitation, and smaller pollen grains appear to adapt better in habitats with extreme conditions. Evolution trends in exine sculpture do not appear to be definitively correlated with pollen size and shape.

  2. Lilium spp. pollen in China (Liliaceae): taxonomic and phylogenetic implications and pollen evolution related to environmental conditions.

    Science.gov (United States)

    Du, Yun-peng; Wei, Chi; Wang, Zhong-xuan; Li, Shuang; He, Heng-bin; Jia, Gui-xia

    2014-01-01

    Recent molecular and karyologic studies have significantly modified delimitation of Lilium. However, despite the importance of pollen evolution in the genus comprehensive studies with electron microscopy and evaluation of pollen evolution are lacking. Therefore, we studied pollen morphology in a sample of 65 individuals from 37 taxa covering all the sections distributed in the world, using scanning electron microscopy. Our collection of 49 individuals from 21 taxa covering all five sections in China was also included in the database. We found pollen tetrads in L. bakerianum. Based on present and previous studies, our results suggest that pollen from L. formosanum should be classified as a new type, Formosanum. Combined with morphological and molecular evidence, pollen sculpture patterns appear to reflect phylogenetic relationships and are useful for species or subsection delimitation. Based on a comprehensive survey and correlation with potential functional implications, we propose the following hypothesis: evolution of an exine sculpture shows pollen type trends from Martagon → Callose → Concolor → Formosanum. The evolutionary trend regarding pollen sculpture and size could be related to selective pressure to adapt to environmental conditions. Pollen size and shape showed a significantly positive correlation with annual precipitation, and smaller pollen grains appear to adapt better in habitats with extreme conditions. Evolution trends in exine sculpture do not appear to be definitively correlated with pollen size and shape.

  3. Considerations for the preparation of peat samples for palynology, and for the counting of pollen and non-pollen palynomorphs

    Directory of Open Access Journals (Sweden)

    F.M. Chambers

    2011-09-01

    Full Text Available Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis, which is often limited to the study of pollen and a few easily recognisable spores; however, a variety of other microfossils can be studied in peat deposits and can provide information on past environmental conditions. Among the so-called non-pollen palynomorphs (NPPs are fungal and algal spores that can be used as indicators for local hydrological changes and trophic conditions. This article provides an overview of aspects to consider and sample preparation methods for pollen, spores and other non-pollen palynomorph microfossils in peat deposits; advice on aids to pollen identification and counting; and a brief guide to the range of NPPs that can be counted from prepared subfossil-pollen microslides.

  4. Identification of sweet chesnut pollen in bee pollen pellet using using molecular analysis.

    Directory of Open Access Journals (Sweden)

    Jana Žiarovská

    2015-10-01

    Full Text Available Castanea sativa posses many characteristics that are used by human for different purposes, not only as a part of the food. One of them is the utilization of the sweet chesnut pollen for its pharmacological benefits. Actually, no information about the DNA based identification of the sweet chesnut exist. Here, an identification of Castanea sativa based on the specific DNA fragment amplification is described for the first time. Sweet chesnut identification was performed in the very complex sample of bee pollen pellets that were identified as to contain sweet chesnut pollen grains by morphological analysis. First, bioinformatic analysis was performed to find a Castanea sativa conservative part of galactol synthase gene. BLAST alignment of the CDS of GolS1 gene was performed by BLASTtn against plants nucleotide sequences in the NCBI database to ensure for the specifity or existing nucleotide differences. Then, specific primers were subsequently designed and PCR amplification was performed. All the PCRs have run in duplicates for pollen pellet sample and two independent samples of Castanea sativa pure pollen. Restriction cleavage of the PCR amplified fragment was performed to confirm the specifity of the obtained PCR product with the positive confirmation as the predicted three restriction fragments were obtained that fully correspond by the length to those from virtual clevage. Restriction endonuclease Hpy166II was used in restriction cleavage analysis. Castanea sativa pollen grains were confirmed reliable in multifloral pollen pellet by PCR and this approach has the potential to be used effectively for the authentication purposes of sweet chesnut.

  5. Performance of moth larvae on birch in relation to altitude, climate, host quality and parasitoids.

    Science.gov (United States)

    Virtanen, Tarmo; Neuvonen, Seppo

    1999-07-01

    We studied topographical and year-to-year variation in the performance (pupal weights, survival) and larval parasitism of Epirrita autumnata larvae feeding on mountain birch in northernmost Finland in 1993-1996. We found differences in both food plant quality and parasitism between sites ranging from 80 m to 320 m above sea level. Variation in food plant quality had particularly marked effects on larval survival. The advanced phenology of the birches in relation to the start of the larval period reduced pupal weights. Parasitism rates were different between years and between sites. The clearest site differences were in the proportions of different parasitoid species: Eulophus larvarum was most abundant at the lowest-altitude sites, and Cotesia jucunda at the highest. Differences in the performance of E. autumnata were related to temperature conditions: at higher temperatures, survival and the egg production index were lower, and larval parasitism was higher than at lower temperatures. The higher parasitism at higher temperatures was probably due to greater parasitoid activity during warmer days. In the comparison of different sources of spatial and annual variation in the performance of E. autumnata, the most important factor appeared to be egg mortality related to minimum winter temperature, followed by parasitism and, finally, the variation in food plant quality. If, as predicted, the climate gradually warms up, the effects of warmer summers on the outbreaks of E. autumnata suggest a decrease in outbreak intensity.

  6. Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches.

    Science.gov (United States)

    Manninen, S; Huttunen, S; Vanhatalo, M; Pakonen, T; Hämäläinen, A

    2009-05-01

    We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O(3)) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O(3), i.e. O(3) levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O(3) and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels.

  7. Quantification of Model Uncertainty in Modeling Mechanisms of Soil Microbial Respiration Pulses to Simulate Birch Effect

    Science.gov (United States)

    Elshall, A. S.; Ye, M.; Niu, G. Y.; Barron-Gafford, G.

    2014-12-01

    A Bayesian framework is developed to quantify predictive uncertainty in environmental modeling caused by uncertainty in modeling scenarios, model structures, model parameters, and data. An example of using the framework to quantify model uncertainty is presented to simulate soil microbial respiration pulses in response to episodic rainfall pulses (the "Birch effect"). A total of five models are developed; they evolve from an existing four-carbon (C) pool model to models with additional C pools and recently developed models with explicit representations of soil moisture controls on C degradation and microbial uptake rates. Markov chain Monte Carlo (MCMC) methods with generalized likelihood function (not Gaussian) are used to estimate posterior parameter distributions of the models, and the posterior parameter samples are used to evaluate probabilities of the models. The models with explicit representations of soil moisture controls outperform the other models. The models with additional C pools for accumulation of degraded C in the dry zone of the soil pore space result in a higher probability of reproducing the observed Birch pulses. A cross-validation is conducted to explore predictive performance of model averaging and of individual models. The Bayesian framework is mathematically general and can be applied to a wide range of environmental problems.

  8. Elastic and Strength Properties of Heat-Treated Beech and Birch Wood

    Directory of Open Access Journals (Sweden)

    Vlastimil Borůvka

    2018-04-01

    Full Text Available This paper deals with the impact of heat treatment on the elastic and strength properties of two diffuse porous hardwoods, namely Fagus sylvatica and Betula pendula. Two degrees of the heat treatment were used at temperatures of 165 °C and 210 °C. The dynamic and static elasticity modulus, bending strength, impact toughness, hardness, and density were tested. It is already known that an increase in treatment temperature decreases the mechanical properties and, on the other hand, leads to a better shape and dimensional stability. Higher temperatures of the heat treatment correlated with lower elastic and strength properties. In the case of higher temperature treatments, the decline of tested properties was noticeable as a result of serious changes in the chemical composition of wood. It was confirmed that at higher temperature stages of treatment, there was a more pronounced decrease in beech properties compared to those of the birch, which was the most evident in their bending strength and hardness. Our research confirmed that there is no reason to consider birch wood to be of a lesser quality, although it is regarded by foresters as an inferior tree species. After the heat treatment, the wood properties are almost the same as in the case of beech wood.

  9. Dominating IgE-binding epitope of Bet v 1, the major allergen of birch pollen, characterized by X-ray crystallography and site-directed mutagenesis

    DEFF Research Database (Denmark)

    Spangfort, Michael D; Mirza, Osman; Ipsen, Henrik

    2003-01-01

    approach to the engineering of allergen molecules with reduced IgE binding. In this study, we describe the identification and modification of a human IgE-binding epitope based on the crystal structure of Bet v 1 in complex with the BV16 Fab' fragment. The epitope occupies approximately 10% of the molecular...... surface area of Bet v 1 and is clearly conformational. A synthetic peptide representing a sequential motif in the epitope (11 of 16 residues) did not inhibit the binding of mAb BV16 to Bet v 1, illustrating limitations in the use of peptides for B cell epitope characterization. The single amino acid...... substitution, Glu(45)-Ser, was introduced in the epitope and completely abolished the binding of mAb BV16 to the Bet v 1 mutant within a concentration range 1000-fold higher than wild type. The mutant also showed up to 50% reduction in the binding of human polyclonal IgE, demonstrating that glutamic acid 45...

  10. Dominating IgE-binding epitope of Bet v 1, the major allergen of birch pollen, characterized by X-ray crystallography and site-directed mutagenesis

    DEFF Research Database (Denmark)

    Spangfort, Michael D; Mirza, Osman; Ipsen, Henrik

    2003-01-01

    Specific allergy vaccination is an efficient treatment for allergic disease; however, the development of safer vaccines would enable a more general use of the treatment. Determination of molecular structures of allergens and allergen-Ab complexes facilitates epitope mapping and enables a rational...

  11. Neonatal colonization of germ-free mice with Bifidobacterium longum prevents allergic sensitization to major birch pollen allergen Bet v 1

    Czech Academy of Sciences Publication Activity Database

    Schwarzer, Martin; Šrůtková, Dagmar; Schabussova, I.; Hudcovic, Tomáš; Akgün, J.; Wiedermann, U.; Kozáková, Hana

    2013-01-01

    Roč. 31, č. 46 (2013), s. 5405-5412 ISSN 0264-410X R&D Projects: GA ČR GA303/09/0449; GA MŠk 7AMB12AT020 Institutional support: RVO:61388971 Keywords : Allergy * Bifidobacterium * Germ-free mice Subject RIV: EC - Immunology Impact factor: 3.485, year: 2013

  12. The blocking activity of birch pollen-specific immunotherapy-induced IgG4 is not qualitatively superior to that of other IgG subclasses

    DEFF Research Database (Denmark)

    Ejrnaes, Anne M; Bødtger, Uffe; Larsen, Jørgen N

    2004-01-01

    blocking activity was found in the purified IgG4 fraction. There was no significant difference in the binding avidities (1/K(d)) measured in the two IgG fractions. Thus, it appears that SIT-induced specific IgG4 contributes to the IgG blocking of allergen binding to IgE in a simple quantitative manner...

  13. Crystallization and preliminary X-ray analysis of birch-pollen allergen Bet v 1 in complex with a murine monoclonal IgG Fab' fragment

    DEFF Research Database (Denmark)

    Spangfort, M D; Mirza, Osman Asghar; Gajhede, M

    1999-01-01

    The human type I allergic response is characterized by the presence of allergen-specific serum immunoglobulin E (IgE). Allergen-mediated cross-linking of receptor-bound IgE on the surface of mast cells and circulating basophils triggers the release of mediators, resulting in the development...

  14. Susceptibility to nasal and oral tolerance induction to the major birch pollen allergen Bet v 1 is not dependent on the presence of the microflora

    Czech Academy of Sciences Publication Activity Database

    Repa, A.; Kozáková, Hana; Hudcovic, Tomáš; Štěpánková, Renata; Hrnčíř, Tomáš; Tlaskalová, Helena; Pollak, A.; Wiedermann, U.

    2008-01-01

    Roč. 117, č. 1 (2008), s. 50-56 ISSN 0165-2478 R&D Projects: GA ČR(CZ) GA303/05/2249; GA ČR GA303/06/0974; GA AV ČR 1QS500200572 Institutional research plan: CEZ:AV0Z50200510 Keywords : gnotobiotics * mucosal immunity * allergy Subject RIV: EC - Immunology Impact factor: 2.858, year: 2008

  15. Pollen Ultrastructure of Genus Dendrobium Orchids as a Learning Resource

    Directory of Open Access Journals (Sweden)

    Lika Dwi Apriani

    2016-11-01

    Full Text Available Anggrek genus Dendrobium merupakan salah satu genus dari divisi spermatophyta yang merupakan kelompok tumbuhan yang berkembang dengan menggunakan biji. Tumbuhan berbiji tentu memiliki bunga sebagai alat perkembangan generatifnya. Perkembangan generatif pada bunga artinya pertemuan antara sel gamet jantan dan sel gamet betina. Sel gamet betina pada tumbuhan dihasilkan oleh putik, sedangkan sel gamet jantan disebut serbuk sari atau pollen. Genus Dendrobium merupakan salah satu kekayaan alam Indonesia, jumlahnya diperkirakan mencapai 275 spesies. Penelitian ini bertujuan untuk mengetahui bagaimana ultrastruktur pollen anggrek genus Dendrobium dari sepuluh spesies yang diamati menggunakan SEM. Jenis penelitian ini adalah deskriptif kualitatif. Hasil penelitian menunjukkan unit pollen untuk semua spesies yaitu kategori pollinia, sedangkan untuk polaritas pollen adalah apolar. Jenis aperture kesepuluh spesies yang diamati mempunyai aperture dengan pola yang tidak beraturan dan lebih dari enam yang disebut colpate. Bentuk pollen dari semua spesies yang diteliti bentuknya adalah subprolate hingga prolate dan ukuran pollen termasuk dalam kategori minuta hingga media. Ornamentasi pollen atau skluptur pollen tidak teridentifikasi dikarenakan ukuran pollen yang terlalu kecil, permukaan pollen terlihat kurang jelas. Sumber belajar yang digunakan adalah atlas.

  16. PECTIN METHYLESTERASE48 is involved in Arabidopsis pollen grain germination.

    Science.gov (United States)

    Leroux, Christelle; Bouton, Sophie; Kiefer-Meyer, Marie-Christine; Fabrice, Tohnyui Ndinyanka; Mareck, Alain; Guénin, Stéphanie; Fournet, Françoise; Ringli, Christoph; Pelloux, Jérôme; Driouich, Azeddine; Lerouge, Patrice; Lehner, Arnaud; Mollet, Jean-Claude

    2015-02-01

    Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme48-/- pollen grains. In contrast, the PME activity was lower in pme48-/-, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme48-/- with the optimum germination medium supplemented with 2.5 mm calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca(2+) necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination. © 2015 American Society of Plant Biologists. All Rights Reserved.

  17. Origin and Functional Prediction of Pollen Allergens in Plants.

    Science.gov (United States)

    Chen, Miaolin; Xu, Jie; Devis, Deborah; Shi, Jianxin; Ren, Kang; Searle, Iain; Zhang, Dabing

    2016-09-01

    Pollen allergies have long been a major pandemic health problem for human. However, the evolutionary events and biological function of pollen allergens in plants remain largely unknown. Here, we report the genome-wide prediction of pollen allergens and their biological function in the dicotyledonous model plant Arabidopsis (Arabidopsis thaliana) and the monocotyledonous model plant rice (Oryza sativa). In total, 145 and 107 pollen allergens were predicted from rice and Arabidopsis, respectively. These pollen allergens are putatively involved in stress responses and metabolic processes such as cell wall metabolism during pollen development. Interestingly, these putative pollen allergen genes were derived from large gene families and became diversified during evolution. Sequence analysis across 25 plant species from green alga to angiosperms suggest that about 40% of putative pollen allergenic proteins existed in both lower and higher plants, while other allergens emerged during evolution. Although a high proportion of gene duplication has been observed among allergen-coding genes, our data show that these genes might have undergone purifying selection during evolution. We also observed that epitopes of an allergen might have a biological function, as revealed by comprehensive analysis of two known allergens, expansin and profilin. This implies a crucial role of conserved amino acid residues in both in planta biological function and allergenicity. Finally, a model explaining how pollen allergens were generated and maintained in plants is proposed. Prediction and systematic analysis of pollen allergens in model plants suggest that pollen allergens were evolved by gene duplication and then functional specification. This study provides insight into the phylogenetic and evolutionary scenario of pollen allergens that will be helpful to future characterization and epitope screening of pollen allergens. © 2016 American Society of Plant Biologists. All rights reserved.

  18. UV-B absorbing pigments in spores: biochemical responses to shade in a high-latitude birch forest and implications for sporopollenin-based proxies of past environmental change

    Directory of Open Access Journals (Sweden)

    Terry V. Callaghan

    2011-08-01

    Full Text Available Current attempts to develop a proxy for Earth's surface ultraviolet-B (UV-B flux focus on the organic chemistry of pollen and spores because their constituent biopolymer, sporopollenin, contains UV-B absorbing pigments whose relative abundance may respond to the ambient UV-B flux. Fourier transform infrared (FTIR microspectroscopy provides a useful tool for rapidly determining the pigment content of spores. In this paper, we use FTIR to detect a chemical response of spore wall UV-B absorbing pigments that correspond with levels of shade beneath the canopy of a high-latitude Swedish birch forest. A 27% reduction in UV-B flux beneath the canopy leads to a significant (p<0.05 7.3% reduction in concentration of UV-B absorbing compounds in sporopollenin. The field data from this natural flux gradient in UV-B further support our earlier work on sporopollenin-based proxies derived from sedimentary records and herbaria collections.

  19. Comprehensive cell-specific protein analysis in early and late pollen development from diploid microsporocytes to pollen tube growth.

    Science.gov (United States)

    Ischebeck, Till; Valledor, Luis; Lyon, David; Gingl, Stephanie; Nagler, Matthias; Meijón, Mónica; Egelhofer, Volker; Weckwerth, Wolfram

    2014-01-01

    Pollen development in angiosperms is one of the most important processes controlling plant reproduction and thus productivity. At the same time, pollen development is highly sensitive to environmental fluctuations, including temperature, drought, and nutrition. Therefore, pollen biology is a major focus in applied studies and breeding approaches for improving plant productivity in a globally changing climate. The most accessible developmental stages of pollen are the mature pollen and the pollen tubes, and these are thus most frequently analyzed. To reveal a complete quantitative proteome map, we additionally addressed the very early stages, analyzing eight stages of tobacco pollen development: diploid microsporocytes, meiosis, tetrads, microspores, polarized microspores, bipolar pollen, desiccated pollen, and pollen tubes. A protocol for the isolation of the early stages was established. Proteins were extracted and analyzed by means of a new gel LC-MS fractionation protocol. In total, 3817 protein groups were identified. Quantitative analysis was performed based on peptide count. Exceedingly stage-specific differential protein regulation was observed during the conversion from the sporophytic to the gametophytic proteome. A map of highly specialized functionality for the different stages could be revealed from the metabolic activity and pronounced differentiation of proteasomal and ribosomal protein complex composition up to protective mechanisms such as high levels of heat shock proteins in the very early stages of development.

  20. Comprehensive Cell-specific Protein Analysis in Early and Late Pollen Development from Diploid Microsporocytes to Pollen Tube Growth*

    Science.gov (United States)

    Ischebeck, Till; Valledor, Luis; Lyon, David; Gingl, Stephanie; Nagler, Matthias; Meijón, Mónica; Egelhofer, Volker; Weckwerth, Wolfram

    2014-01-01

    Pollen development in angiosperms is one of the most important processes controlling plant reproduction and thus productivity. At the same time, pollen development is highly sensitive to environmental fluctuations, including temperature, drought, and nutrition. Therefore, pollen biology is a major focus in applied studies and breeding approaches for improving plant productivity in a globally changing climate. The most accessible developmental stages of pollen are the mature pollen and the pollen tubes, and these are thus most frequently analyzed. To reveal a complete quantitative proteome map, we additionally addressed the very early stages, analyzing eight stages of tobacco pollen development: diploid microsporocytes, meiosis, tetrads, microspores, polarized microspores, bipolar pollen, desiccated pollen, and pollen tubes. A protocol for the isolation of the early stages was established. Proteins were extracted and analyzed by means of a new gel LC-MS fractionation protocol. In total, 3817 protein groups were identified. Quantitative analysis was performed based on peptide count. Exceedingly stage-specific differential protein regulation was observed during the conversion from the sporophytic to the gametophytic proteome. A map of highly specialized functionality for the different stages could be revealed from the metabolic activity and pronounced differentiation of proteasomal and ribosomal protein complex composition up to protective mechanisms such as high levels of heat shock proteins in the very early stages of development. PMID:24078888

  1. Flow cytometric analysis of pollen grains collected from individual bees provides information about pollen load composition and foraging behaviour.

    Science.gov (United States)

    Kron, Paul; Kwok, Allison; Husband, Brian C

    2014-01-01

    Understanding the species composition of pollen on pollinators has applications in agriculture, conservation and evolutionary biology. Current identification methods, including morphological analysis, cannot always discriminate taxa at the species level. Recent advances in flow cytometry techniques for pollen grains allow rapid testing of large numbers of pollen grains for DNA content, potentially providing improved species resolution. A test was made as to whether pollen loads from single bees (honey-bees and bumble-bees) could be classified into types based on DNA content, and whether good estimates of proportions of different types could be made. An examination was also made of how readily DNA content can be used to identify specific pollen species. The method allowed DNA contents to be quickly found for between 250 and 9391 pollen grains (750-28 173 nuclei) from individual honey-bees and between 81 and 11 512 pollen grains (243-34 537 nuclei) for bumble-bees. It was possible to identify a minimum number of pollen species on each bee and to assign proportions of each pollen type (based on DNA content) present. The information provided by this technique is promising but is affected by the complexity of the pollination environment (i.e. number of flowering species present and extent of overlap in DNA content). Nevertheless, it provides a new tool for examining pollinator behaviour and between-species or cytotype pollen transfer, particularly when used in combination with other morphological, chemical or genetic techniques.

  2. Quality of durable cookies enriched with rape bee pollen

    Directory of Open Access Journals (Sweden)

    Miriam Solgajová

    2014-03-01

    Full Text Available The objective of this study was to enrich durable cookies with different additions of rape (Brassica napus var. napus bee pollen to increase nutritional properties of cookie samples and to improve technological and sensorial properties as well. Bee pollen is an important raw material due to its nutritional and functional properties. Cookie samples were prepared by substituting wheat flour with rape bee pollen in the amount of 16 % (1 g of bee pollen per cookie and 32 % (2 g of bee pollen per cookie using bee pollen from two localities Lenártovce and Nové Zámky. In baked samples beside sensory properties also chemical parameters and technological parameters of cookies were evaluated. It was found out that with the gradual addition of rape bee pollen the amount of ash content increased and the highest ash content was analysed in variants II and IV (0.71 and 0.77 % using 32 % addition of rape bee pollen. In terms of reducing sugars, addition of bee pollen caused that the content of reducing sugars in the products increased slightly. The highest reducing sugar content was determined in variant II. (24.59 %. On the other hand amount of crude protein the most considerably raised by addition of 2 g of pollen per cookie. The highest content of crude protein was analysed in variants II and IV (8.72 and 9.00 %. From the results of a linear models in which the dependent variables were the ash, crude protein and moisture it was determined the significant effect (p <0.05 only of the pollen addition. In the case of the model with the dependent variable reducing sugars it was found out significant effect (p<0.0001 of pollen addition and locality and their interactions. With the gradual addition of bee pollen values of technological parameters such as diameter and weight of cookies increased and thickness of products decreased. Based on sensory scores using a 9-point Hedonic scale the best sensorial acceptability (7.4 was found in variant I (1 g of bee

  3. Comparative Analysis of the Arabidopsis Pollen Transcriptome

    Czech Academy of Sciences Publication Activity Database

    Honys, David; Twell, D.

    2003-01-01

    Roč. 132, - (2003), s. 640ů652 ISSN 0032-0889 R&D Projects: GA AV ČR IAA5038207 Grant - others:Royal Society(GB) NATO Postdoctoral Fellowship (to D.H.) Institutional research plan: CEZ:AV0Z5038910; CEZ:MSM 113100003 Keywords : transcriptome profiling * Arabidopsis pollen * male gametophyte Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.634, year: 2003

  4. Assessing the Potential Stem Growth and Quality of Yellow Birch Prior to Restoration: A Case Study in Eastern Canada

    Directory of Open Access Journals (Sweden)

    Alexis Achim

    2013-09-01

    Full Text Available Past silvicultural treatments have resulted in the high-grading mixed temperate forests of Québec, Canada. Despite recognition of this issue, the low occurrence of yellow birch (Betula alleghaniensis Britton within current stands raises questions about the potential of the species to grow and eventually constitute a high-quality forest resource. The objective of this study was to assess this potential using tree characteristics, forest structure and additional site and climatic conditions as predictors. A total of 145 trees were sampled in two areas located in the same bioclimatic zone. Lower-Saguenay-Charlevoix was chosen as an area where a restoration plan could be implemented, whereas Portneuf was selected as a reference. We used nonlinear mixed models to investigate which environmental factors are likely to influence the radial growth and stem quality of yellow birch sample trees. Our results suggest that topographic and climatic conditions, as well as the competitive environment of the trees, are important factors to consider in the evaluation of yellow birch production. Despite the limited occurrence of yellow birch, the potential for growth and quality was high in the Lower-Saguenay-Charlevoix area. For equivalent topographic, climatic, and competitive environment conditions, there was no significant difference in either radial growth or stem quality with Portneuf. We suggest that the economic interest of producing high quality timber should be used to justify the implementation of a restoration strategy in the Lower-Saguenay-Charlevoix area.

  5. Comparison of various sampling methods for evaluation of biodiversity of true bugs (Heteroptera) in a birch forest

    Czech Academy of Sciences Publication Activity Database

    Kula, E.; Bryja, Josef

    2002-01-01

    Roč. 21, č. 2 (2002), s. 137-147 ISSN 1335-342X R&D Projects: GA ČR GA526/98/0537; GA MŽP SE/830/3/00 Institutional research plan: CEZ:AV0Z6093917 Keywords : Heteroptera * birch forest * biodiversity Subject RIV: GK - Forestry Impact factor: 0.246, year: 2002

  6. The influence of log soaking temperature on surface quality and integrity performance of birch (Betula pendula Roth) veneer

    Science.gov (United States)

    Anti Rohumaa; Toni Antikainen; Christopher G. Hunt; Charles R. Frihart; Mark Hughes

    2016-01-01

    Wood material surface properties play an important role in adhesive bond formation and performance. In the present study, a test method was developed to evaluate the integrity of the wood surface, and the results were used to understand bond performance. Materials used were rotary cut birch (Betula pendula Roth) veneers, produced from logs soaked at 20 or 70 °C prior...

  7. 78 FR 69848 - Birch Power Company; Notice of Proposed Revised Restricted Service List for a Programmatic Agreement

    Science.gov (United States)

    2013-11-21

    ...] Birch Power Company; Notice of Proposed Revised Restricted Service List for a Programmatic Agreement..., the Secretary may establish a restricted service list for a particular phase or issue in a proceeding. The restricted service list should contain the names of persons on the service list who, in the...

  8. Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems

    Directory of Open Access Journals (Sweden)

    Markus Armbruster

    2017-03-01

    Full Text Available Triterpene compounds like betulin, betulinic acid, erythrodiol, oleanolic acid and lupeol are known for many pharmacological effects. All these substances are found in the outer bark of birch. Apart from its pharmacological effects, birch bark extract can be used to stabilise semisolid systems. Normally, birch bark extract is produced for this purpose by extraction with organic solvents. Employing supercritical fluid technology, our aim was to develop a birch bark dry extract suitable for stabilisation of lipophilic gels with improved properties while avoiding the use of toxic solvents. With supercritical carbon dioxide, three different particle formation methods from supercritical solutions have been tested. First, particle deposition was performed from a supercritical solution in an expansion chamber. Second, the Rapid Expansion of Supercritical Solutions (RESS method was used for particle generation. Third, a modified RESS-procedure, forming the particles directly into the thereby gelated liquid, was developed. All three methods gave yields from 1% to 5.8%, depending on the techniques employed. The triterpene composition of the three extracts was comparable: all three gave more stable oleogels compared to the use of an extract obtained by organic solvent extraction. Characterizing the rheological behaviour of these gels, a faster gelling effect was seen together with a lower concentration of the extract required for the gel formation with the supercritical fluid (SCF-extracts. This confirms the superiority of the supercritical fluid produced extracts with regard to the oleogel forming properties.

  9. Academic Success for Students of Color . . . At What Cost? The Importance of School Context at Birch High School

    Science.gov (United States)

    Chambers, Terah T. Venzant; Tabron, Lolita A.

    2013-01-01

    Kiara, an African American rising freshman, has aspirations to become a medical doctor. She enrolls at Birch High School because of the reputation of the principal, Mr. Brown, whose vision for academic excellence permeates every corner of the school. Kiara graduates from high school with top honors, but realizes her success may have come at a…

  10. Pollen morphology of Cornus mas L. and Cornus sanguinea L.

    OpenAIRE

    Karlıoğlu Kılıç, Nurgül; Tuttu, Gamze

    2017-01-01

    Pollen morphology of Cornus mas L. and Cornus sanguinea L.Abstract: The pollen morphology of 2 species of the genus Cornus L. distributed in Turkey was studied with light and scanning electron microscope. The pollen of genus Cornus is 3-colporate. Pollen of the Cornus mas is spheroidal and Cornus sanguinea is subprolate. Size varies of Cornus mas pollen with the polar axis ranging from 21.54 to 27.36 μm and equatorial axis from 21.31 to 26.72 μm. Size varies of Cornus sanguinea pollen with po...

  11. She's the boss: signaling in pollen tube reception.

    Science.gov (United States)

    Kessler, Sharon A; Grossniklaus, Ueli

    2011-10-01

    In angiosperms, the sperm cells are carried within the pollen tubes (male gametophytes) to the female gametophyte so that double fertilization can occur. The female gametophyte exerts control over the male, with specialized cells known as synergids guiding the pollen tubes and controlling their behavior when they enter the female gametophyte so that the sperm cells can be delivered to the egg and central cell. Upon pollen tube arrival at the ovule, signal transduction cascades mediated by receptor-like kinases are initiated in both the synergid and the tip of the pollen tube, leading to synergid cell death and pollen tube rupture. In this review, we discuss the role of these receptors and of newly discovered members of the pollen tube reception pathway. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Citrus Allergy from Pollen to Clinical Symptoms

    Science.gov (United States)

    Iorio, Rosa Anna; Del Duca, Stefano; Calamelli, Elisabetta; Pula, Chiara; Lodolini, Magda; Scamardella, Fortuna; Pession, Andrea; Ricci, Giampaolo

    2013-01-01

    Allergy to citrus fruits is often associated with pollinosis and sensitization to other plants due to a phenomenon of cross-reactivity. The aims of the present study were to highlight the cross-reactivity among citrus and the major allergenic pollens/fruits, throughout clinical and molecular investigations, and to evaluate the sensitization frequency to citrus fruits in a population of children and adults with pollinosis. We found a relevant percentage of sensitisation (39%) to citrus fruits in the patients recruited and in all of them the IgE-mediated mechanism has been confirmed by the positive response to the prick-to-prick test. RT-PCR experiments showed the expression of Cit s 1, Cit s 3 and a profilin isoform, already described in apple, also in Citrus clementine pollen. Data of multiple sequence alignments demonstrated that Citrus allergens shared high percentage identity values with other clinically relevant species (i.e. Triticum aestivum, Malus domestica), confirming the possible cross-allergenicity citrus/grasses and citrus/apple. Finally, a novelty of the present work has been the expression of two phospholipaseA2 isoforms (PLA2 α and β) in Citrus as well as in Triticum pollens; being PLA2 able to generate pro-inflammatory factors, this enzyme could participate in the activation of the allergenic inflammatory cascade. PMID:23308273

  13. Citrus allergy from pollen to clinical symptoms.

    Directory of Open Access Journals (Sweden)

    Rosa Anna Iorio

    Full Text Available Allergy to citrus fruits is often associated with pollinosis and sensitization to other plants due to a phenomenon of cross-reactivity. The aims of the present study were to highlight the cross-reactivity among citrus and the major allergenic pollens/fruits, throughout clinical and molecular investigations, and to evaluate the sensitization frequency to citrus fruits in a population of children and adults with pollinosis. We found a relevant percentage of sensitisation (39% to citrus fruits in the patients recruited and in all of them the IgE-mediated mechanism has been confirmed by the positive response to the prick-to-prick test. RT-PCR experiments showed the expression of Cit s 1, Cit s 3 and a profilin isoform, already described in apple, also in Citrus clementine pollen. Data of multiple sequence alignments demonstrated that Citrus allergens shared high percentage identity values with other clinically relevant species (i.e. Triticum aestivum, Malus domestica, confirming the possible cross-allergenicity citrus/grasses and citrus/apple. Finally, a novelty of the present work has been the expression of two phospholipaseA2 isoforms (PLA2 α and β in Citrus as well as in Triticum pollens; being PLA2 able to generate pro-inflammatory factors, this enzyme could participate in the activation of the allergenic inflammatory cascade.

  14. Pollen-gamma irradiation on pineapple and pollination using irradiated pollen

    International Nuclear Information System (INIS)

    Benega, R.; Cisneros, A.; Martinez, J.; Arias, E.; Yabor, L.; Isidron, M.; Castillo, E.; Fernandez, J.

    1997-01-01

    In order to try to induce haploid plants, pineapple (Ananas comosus (L.) ;err.) pollen grains were gamma-rays irradiated with a Co 60 source at rates of doses from 0 to 300 Gy. The effect of gamma-rays on the generative-nucleus division and vitro pollen viability as well as, seed contents and plantlets obtained after pollinations was analysed. The were reducing in the division frequencies of generative nucleus at all assayed doses. The LD50 was achieved among 200 and 250 Gy. There were not differences on pollen viability in the rates of assayed doses. Seed contents were dose-dependent. The percentages of seed full and seed containing only embryos decreases at increasing of irradiation doses. Contrary effect was observed on the seed empty. Some plantlets regenerated from the different irradiation doses showed phenotypes with small and leaves and short inter nodes

  15. Urtica dioica pollen allergy: Clinical, biological, and allergomics analysis.

    Science.gov (United States)

    Tiotiu, Angelica; Brazdova, Andrea; Longé, Cyril; Gallet, Patrice; Morisset, Martine; Leduc, Virginie; Hilger, Christiane; Broussard, Cédric; Couderc, Rémy; Sutra, Jean-Pierre; Sénéchal, Hélène; Poncet, Pascal

    2016-11-01

    The most emblematic members of Urticaceae at allergic risk level are wall pellitories (Parietaria), whereas nettle (Urtica) pollen is considered as poorly allergenic. No allergen from nettle pollen has yet been characterized, whereas 4 are listed for Parietaria pollen by the International Union of Immunological Societies. Clinical and biological profiles of 2 adult men who developed symptoms against nettle pollen and/or leaves were studied. To characterize the allergic reaction and identify the potential nettle pollen sensitizing allergens. IgE-mediated reaction to nettle pollen extract was evaluated by skin prick test, immunoassay, nasal provocation, and basophil activation test. To characterize specific nettle pollen allergens, an allergomic (IgE immunoproteomic) analysis was performed combining 1- and 2-dimensional electrophoresis, IgE immunoblots of nettle pollen extract, identification of allergens by mass spectrometry, and database queries. The results of biological and immunochemical analyses revealed that the allergic rhinitis was due to Urtica dioica pollen in both patients. The allergomic analysis of nettle pollen extract allowed the characterization of 4 basic protein allergens: a thaumatin-like protein (osmotin) with a relative molecular mass of 27 to 29 kDa, a pectinesterase (relative molecular mass, 40 kDa), and 2 other basic proteins with relative molecular masses of 14 to 16 kDa and 43 kDa. There is no or only very weak allergen associations between pellitory and nettle pollen. Exposure to nettle pollen can be responsible of allergic symptoms, and several allergens were characterized. Unravelling the allergens of this underestimated allergy might help to improve diagnosis and care for patients, to predict cross-reactivities and design adapted specific immunotherapy. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  16. In vivo pollination with maize pollen stored in aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Broglia, M. [ENEA, Casaccia (Italy). Area Energia e Innovazione

    1994-11-01

    A hypertonic aqueous medium can be used to obtain non-bursting, non-germinating maize (zea mays L.) pollen suspensions, which can be stored at 0{sub 0}C preserving pollen viability. This medium could be used in different techniques for maize pollen genetic manipulation, but fertilization ability of such stored pollen has to be proved. In this work, pollen stored in different hypertonic media was used to perform in vivo pollinations by different techniques. Uncut silks and pollen filtered in a paste form were found necessary perequisites for a fruitfull pollen-silk interaction. In the 0.5-1.5 M range a highter sucrose concentration increases storability but decreases fertilization ability. Salts as KNO{sub 3} and CaCl{sub 2} were also explored in an osmotic concentration range. Considering that soluble calcium, needful for germination, can be lost from pollen in aqueous media, a hypertonic aqueous medium osmotically balanced in calcium and sucrose contents was tested as storage medium. Pollen stored several hours in this medium produced numerous seed sets; the high variability of the obtained results made evident the crucial role of silk status in successful pollinations.

  17. Fraxinus pollen as a source of environmental pollution

    Directory of Open Access Journals (Sweden)

    María Fernández-González

    2016-06-01

    Full Text Available In Southern Europe there are but a few studies focused on the allergenic impact of ash (Fraxinus pollen as a result of its scarce distribution. In the city of Ourense this type of pollen represents 2% of the total atmospheric pollen recorded. The goal of this study is to determine the atmospheric concentrations of Fraxinus pollen and its allergen in Ourense’s atmosphere in 2015, and to assess their relationship with the main meteorological variables. The aim is to assess whether the pollen counts match the actual exposure conditions for allergen-sensitive patients. A Lanzoni VPPS-2000 volumetric sampler was used for pollen sampling, whereas a Burkard Cyclone sampler was used for allergen detection.The flowering period of Fraxinus was long, having a duration of 76 days between the third week of January and the rst week of April as consequence of the asynchronous flowering of the different species growing in the study area. The presence of the ash allergen in the atmosphere can be detected using the main olive tree allergen, Ole e 1. Our study indicates that the combination of pollen counts and allergen quanti cation should be contemplated to estimate the real exposure of sensitive people. In the case of Fraxinus pollen, there may be allergy risk periods before and after the occurrence of the highest pollen concentrations in the atmosphere as a result of special rain and humidity conditions during its flowering period.

  18. Intra-inflorescence pollen viability in accessions of Brachiaria ruziziensis

    Directory of Open Access Journals (Sweden)

    Cristina Maria Pinto de Paula

    2014-05-01

    Full Text Available Knowledge about the pollen viability is important to ensure success in controlled hybridizations and, consequently, support breeding programs. The aims of this study were to evaluate the pollen viability in progenies of artificially induced tetraploid accessions of Brachiaria ruziziensis, and to verify if the position of the flower buds on the raceme affects the pollen viability rate. Staining of aborted and non-aborted pollen (Alexander’s technique was used to determine the viability of the pollen grains. Tetraploid accessions of B. ruziziensis plants had high pollen viability (x = 76.8% to x = 99.6%. Some of these plants had viability rates similar to diploid B. ruziziensis, showing that the induction of chromosome duplication by colchicine did not result in abnormalities in production and morphology of pollen grains. Pollen grains from middle and apical regions of the raceme presented higher viability rates (x = 97.9% and x = 97.7% respectively. The viability of pollen grains in artificially induced tetraploid accessions of B. ruziziensis plants was high, which may favor obtaining fertile descendants in possible crosses

  19. A DNA barcoding approach to characterize pollen collected by honeybees.

    Directory of Open Access Journals (Sweden)

    Andrea Galimberti

    Full Text Available In the present study, we investigated DNA barcoding effectiveness to characterize honeybee pollen pellets, a food supplement largely used for human nutrition due to its therapeutic properties. We collected pollen pellets using modified beehives placed in three zones within an alpine protected area (Grigna Settentrionale Regional Park, Italy. A DNA barcoding reference database, including rbcL and trnH-psbA sequences from 693 plant species (104 sequenced in this study was assembled. The database was used to identify pollen collected from the hives. Fifty-two plant species were identified at the molecular level. Results suggested rbcL alone could not distinguish among congeneric plants; however, psbA-trnH identified most of the pollen samples at the species level. Substantial variability in pollen composition was observed between the highest elevation locality (Alpe Moconodeno, characterized by arid grasslands and a rocky substrate, and the other two sites (Cornisella and Ortanella at lower altitudes. Pollen from Ortanella and Cornisella showed the presence of typical deciduous forest species; however in samples collected at Ortanella, pollen of the invasive Lonicera japonica, and the ornamental Pelargonium x hortorum were observed. Our results indicated pollen composition was largely influenced by floristic local biodiversity, plant phenology, and the presence of alien flowering species. Therefore, pollen molecular characterization based on DNA barcoding might serve useful to beekeepers in obtaining honeybee products with specific nutritional or therapeutic characteristics desired by food market demands.

  20. A study of airborne Ulmaceae pollen in Modena (northern Italy).

    Science.gov (United States)

    Torri, P; Accorsi, C A; Bandini Mazzanti, M; Zagni, A M

    1997-01-01

    We examined Ulmaceae airborne pollen at the Modena-Geophysical Observatory monitoring station in 1993. The pollen trap was placed 15 m above the ground. 365 daily slides were fully analyzed to obtain daily and bi-hourly pollen concentrations. Morphological analysis on native and introduced Ulmaceae pollen was also conducted between February 3rd and May 17th. Five pollen types were identified: Celtis cf. australis, Ulmus glabra, Ulmus cf. laevis, Ulmus cf. minor, and Ulmus minor/laevis. Pollen concentrations and percentages showed that the Elm family contributed little pollen to the air (about 1% of the total pollen recorded), Ulmus and Celtis being 0.9% and 0.04%, respectively. The maximum levels were 30 p/m3/24 hr and 118 p/m3/ 2 hr (Ulmus) and 4 p/m3/24 hr and 13 p/m3/2 hr (Celtis). The highest levels of Ulmus were during the morning and afternoon, while the afternoon was highest for Celtis. In general, Ulmaceae trees appear worth planting in urban areas, but Celtis pollen should also be monitored at human height.

  1. A statistical mixture model for estimating the proportion of unreduced pollen grains in perennial ryegrass (Lolium perenne L.) via the size of pollen grains

    NARCIS (Netherlands)

    Jansen, R.C.; Nijs, A.P.M. den

    1993-01-01

    The size of pollen grains is commonly used to indicate the ploidy level of pollen grains. In this paper observations of the diameter of pollen grains are evaluated from one diploid accession of perennial ryegrass (Lolium perenne L.), which was expected to produce diploid (unreduced) pollen grains in

  2. Soil Chemical and Microbial Properties in a Mixed Stand of Spruce and Birch in the Ore Mountains (Germany—A Case Study

    Directory of Open Access Journals (Sweden)

    Karoline Schua

    2015-06-01

    Full Text Available A major argument for incorporating deciduous tree species in coniferous forest stands is their role in the amelioration and stabilisation of biogeochemical cycles. Current forest management strategies in central Europe aim to increase the area of mixed stands. In order to formulate statements about the ecological effects of mixtures, studies at the stand level are necessary. In a mixed stand of Norway spruce (Picea abies (L. Karst. and silver birch (Betula pendula Roth in the Ore Mountains (Saxony, Germany, the effects of these two tree species on chemical and microbial parameters in the topsoil were studied at one site in the form of a case study. Samples were taken from the O layer and A horizon in areas of the stand influenced by either birch, spruce or a mixture of birch and spruce. The microbial biomass, basal respiration, metabolic quotient, pH-value and the C and N contents and stocks were analysed in the horizons Of, Oh and A. Significantly higher contents of microbial N were observed in the Of and Oh horizons in the birch and in the spruce-birch strata than in the stratum containing only spruce. The same was found with respect to pH-values in the Of horizon and basal respiration in the Oh horizon. Compared to the spruce stratum, in the birch and spruce-birch strata, significantly lower values were found for the contents of organic C and total N in the A horizon. The findings of the case study indicated that single birch trees have significant effects on the chemical and microbial topsoil properties in spruce-dominated stands. Therefore, the admixture of birch in spruce stands may distinctly affect nutrient cycling and may also be relevant for soil carbon sequestration. Further studies of these functional aspects are recommended.

  3. Considerations for the preparation of peat samples for palynology, and for the counting of pollen and non-pollen palynomorphs

    OpenAIRE

    Chambers, F.M.; van Geel, B.; van der Linden, M.

    2011-01-01

    Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis), which is often limited to the study of pollen and a few easily recognisable spores; however, a variety of other microfossils can be studied in peat deposits and can provide information on past environmental conditions. Among the so-called non-pollen palynomorphs (NPPs) are ...

  4. Soil Properties Control Glyphosate Sorption in Soils Amended with Birch Wood Biochar

    DEFF Research Database (Denmark)

    Kahawaththa Gamage, Inoka Damayanthi Kumari; Moldrup, Per; Paradelo, Marcos

    2016-01-01

    Abstract Despite a contemporary interest in biochar application to agricultural fields to improve soil quality and long-term carbon sequestration, a number of potential side effects of biochar incorporation in field soils remain poorly understood, e.g., in relation to interactions...... with agrochemicals such as pesticides. In a fieldbased study at two experimental sites in Denmark (sandy loam soils at Risoe and Kalundborg), we investigated the influence of birch wood biochar with respect to application rate, aging (7–19 months), and physico- chemical soil properties on the sorption coefficient......, Kd (L kg−1), of the herbicide glyphosate. We measured Kd in equilibrium batch sorption experiments with triplicate soil samples from 20 field plots that received biochar at different application rates (0 to 100 Mg ha−1). The results showed that pure biochar had a lower glyphosate Kd value as compared...

  5. Breeding increases the efficacy of Chondrostereum purpureum in the sprout control of birch.

    Directory of Open Access Journals (Sweden)

    Leena Hamberg

    Full Text Available We tested whether the pairing of selected isolates could be used to increase the efficiency of a decay fungus Chondrostereum purpureum (Pers. Ex Fr. Pouzar to control hardwood sprouting in Finland. We paired C. purpureum strains efficient in sprout control or highly active in laccase production, and tested the efficacy of their progeny in spout control experiments. This procedure resulted in a strain with an efficacy superior to that of the parental strains. The mortality of birch (Betula pendula Roth. and B. pubescens Ehrh. 1 cm in stump diameter was 78%, 56% and 9% for the best progeny, the best parental strain and the control, respectively. Mortality was only slightly higher for B. pendula than for B. pubescens but no significant differences were found between the number or maximum height of stump sprouts. Our results showed that cross breeding of this decay fungus is a good alternative in attempts to produce efficient biocontrol agents against hardwood sprouting.

  6. Simple methods for in vitro pollen germination and pollen preservation of selected species of the genus Agave

    Directory of Open Access Journals (Sweden)

    Sigifredo López Díaz

    2008-01-01

    Full Text Available Simple methods to evaluate the viability and to preserve Agave tequilana Weber var. azul and A. angustifolia Haw pollen were established. Pollen viability was assessed by improving a growing media and evaluating three common pollen germination media components: sucrose, boric acid, and calcium ion. Optimal germination of pollen was obtained at 0.300 M sucrose, 0.324 mM boric acid, and 1.219 mM calcium nitrate and incubated at a temperature of 25°C. Agave pollen was preserved in olive oil and organic solvents. Olive oil, which is immiscible with water, provides an anhydrous environment and limits available oxygen, conditions similar to those provided by some organic solvents. Fresh pollen was put into eppendorf tubes containing n-butanol, n-propanol, isopropanol, extra virgin olive oil and preserved at -20, 4, and 25°C. The germination of the preserved pollen was scored at different time periods during preservation employing the optimal germination medium. The viability of pollen grains preserved at -20°C in olive oil, proved olive oil as an efficient medium for agave pollen preservation for at least 6 months.

  7. Wood ants and a geometrid defoliator of birch: predation outweighs beneficial effects through the host plant.

    Science.gov (United States)

    Karhu, Kari J; Neuvonen, Seppo

    1998-02-01

    Soil amelioration by a wood-ant species and its consequences for the larval performance of autumnal moths feeding on mountain birch were studied at various distances from the nest mound. Soil nitrate and ammonium nitrogen did not show any clear relationship with distance. However, trees growing in the mound had over 20% more foliar nitrogen than more distant trees. When moth larvae were experimentally protected from predation, their survival rate and final weight tended to decrease with increasing distance. In a laboratory experiment with detached leaves, the relative growth rate of larvae was roughly 30% higher on leaves from trees located on the mound. Differences in larval performance refute the Plant Stress Hypothesis proposed by T.C.R. White and support P.W. Price's Plant Vigor Hypothesis. Predation by ants was examined along the same gradient in trees with and without a glue band that excluded ants from the canopy. Reduction in the daily survival rate of larvae attributable to ant predation was about 35% in trees growing in the mound and around 5% at a distance of 20 m. Other things being equal, about 25 times more larvae entering the penultimate instar would achieve the pupal stage outside the wood-ant territory than in the vicinity of the mound. While both the fertilizing and predatory influence of wood ants is clear, the domain of predation is much larger than the area where trees and their herbivores can exploit enhanced nutrient levels in and around ant mounds. The existence of undamaged green islands around ant mounds in otherwise totally defoliated mountain-birch forests cannot be explained by soil amelioration by wood ants but rather by their predatory activity.

  8. CO 2 elevation improves photosynthetic performance in progressive warming environment in white birch seedlings.

    Science.gov (United States)

    Zhang, Shouren; Dang, Qing-Lai

    2013-01-01

    White birch (Betula paperifera Mash) seedlings were exposed to progressively warming in greenhouses under ambient and elevated CO 2 concentrations for 5 months to explore boreal tree species' potential capacity to acclimate to global climate warming and CO 2 elevation. In situ foliar gas exchange, in vivo carboxylation characteristics and chlorophyll fluorescence were measured at temperatures of 26 (o)C and 37 (o)C. Elevated CO 2 significantly increased net photosynthetic rate (Pn) at both measurement temperatures, and Pn at 37 (o)C was higher than that at 26 (o)C under elevated CO 2. Stomatal conductance (gs) was lower at 37 (o)C than at 26 (o)C, while transpiration rate (E) was higher at 37 (o)C than that at 26 (o)C. Elevated CO 2 significantly increased instantaneous water-use efficiency (WUE) at both 26 (o)C and 37 (o)C, but WUE was markedly enhanced at 37 (o)C under elevated CO 2. The effect of temperature on maximal carboxylation rate (Vcmax), PAR-saturated electron transport rate (Jmax) and triose phosphate utilization (TPU) varied with CO 2, and the Vcmax and Jmax were significantly higher at 37 (o)C than at 26 (o)C under elevated CO 2. However, there were no significant interactive effects of CO 2 and temperature on TPU. The actual photochemical efficiency of PSII (DF/ Fm'), total photosynthetic linear electron transport rate through PSII (JT) and the partitioning of JT to carboxylation (Jc) were higher at 37 (o)C than at 26 (o)C under elevated CO 2. Elevated CO 2 significantly suppressed the partitioning of JT to oxygenation (Jo/JT). The data suggest that the CO 2 elevation and progressive warming greatly enhanced photosynthesis in white birch seedlings in an interactive fashion.

  9. The AMS dating of pollen from syngenetic ice-wedge ice

    Energy Technology Data Exchange (ETDEWEB)

    Vasil' chuk, Alla C. E-mail: vasilch@orc.ru; Kim, Jong-Chan; Vasil' chuk, Yurij K

    2004-08-01

    The features of pollen occurrence in ice-wedge ice such as: size of pollen of tundra plants, incoming pollen into frost cracks together with melt water, dust and partially from host sediment and also clay envelopes around pollen grains caused the pretreatment methods of ice-wedge ice samples. Good preservation of thin-wall pollen grains of Salix and Liliaceae after pretreatment evidenced appropriate pretreatment procedure. There is evident correlation between pollen dates and re-deposited pollen and spores content. However an interpretation of {sup 14}C dating of pollen concentrate is required independent time scale such as annual laminas or the AMS dates of macro or microfossils.

  10. Inbreeding and oubreeding effects on pollen fitness and zygote survival in Silene nutans (Caryophyllaceae)

    DEFF Research Database (Denmark)

    Hauser, Thure Pavlo; Siegismund, H.R.

    2000-01-01

    inbreeding depression, oubreeding effects, outcrossing, pollen fitness, selfing, Silene nutans, zygote survival......inbreeding depression, oubreeding effects, outcrossing, pollen fitness, selfing, Silene nutans, zygote survival...

  11. Tracking maize pollen development by the Leaf Collar Method.

    Science.gov (United States)

    Begcy, Kevin; Dresselhaus, Thomas

    2017-12-01

    An easy and highly reproducible nondestructive method named the Leaf Collar Method is described to identify and characterize the different stages of pollen development in maize. In plants, many cellular events such as meiosis, asymmetric cell division, cell cycle regulation, cell fate determination, nucleus movement, vacuole formation, chromatin condensation and epigenetic modifications take place during pollen development. In maize, pollen development occurs in tassels that are confined within the internal stalk of the plant. Hence, identification of the different pollen developmental stages as a tool to investigate above biological processes is impossible without dissecting the entire plant. Therefore, an efficient and reproducible method is necessary to isolate homogeneous cell populations at individual stages throughout pollen development without destroying the plant. Here, we describe a method to identify the various stages of pollen development in maize. Using the Leaf Collar Method in the maize inbreed line B73, we have determined the duration of each stage from pollen mother cells before meiosis to mature tricellular pollen. Anther and tassel size as well as percentage of pollen stages were correlated with vegetative stages, which are easily recognized. The identification of stage-specific genes indicates the reproducibility of the method. In summary, we present an easy and highly reproducible nondestructive method to identify and characterize the different stages of pollen development in maize. This method now opens the way for many subsequent physiological, morphological and molecular analyses to study, for instance, transcriptomics, metabolomics, DNA methylation and chromatin patterns during normal and stressful conditions throughout pollen development in one of the economically most important grass species.

  12. In vitro pollen germination, pollen tube growth and longevity in some ...

    African Journals Online (AJOL)

    Loquat (Eriobotrya japonica Lindl.) is one of the most perspective trees with tasty fruits suitable for commercial production in Iran. However, self-incompatibility of most loquat cultivars makes it necessary to select good pollinizers in breeding and orchard establishment programs. Therefore, studies on pollen viability traits of ...

  13. Interference of the Histone Deacetylase Inhibits Pollen Germination and Pollen Tube Growth in Picea wilsonii Mast.

    Directory of Open Access Journals (Sweden)

    Yaning Cui

    Full Text Available Histone deacetylase (HDAC is a crucial component in the regulation of gene expression in various cellular processes in animal and plant cells. HDAC has been reported to play a role in embryogenesis. However, the effect of HDAC on androgamete development remains unclear, especially in gymnosperms. In this study, we used the HDAC inhibitors trichostatin A (TSA and sodium butyrate (NaB to examine the role of HDAC in Picea wilsonii pollen germination and pollen tube elongation. Measurements of the tip-focused Ca2+ gradient revealed that TSA and NaB influenced this gradient. Immunofluorescence showed that actin filaments were disrupted into disorganized fragments. As a result, the vesicle trafficking was disturbed, as determined by FM4-64 labeling. Moreover, the distribution of pectins and callose in cell walls was significantly altered in response to TSA and NaB. Our results suggest that HDAC affects pollen germination and polarized pollen tube growth in Picea wilsonii by affecting the intracellular Ca2+ concentration gradient, actin organization patterns, vesicle trafficking, as well as the deposition and configuration of cell wall components.

  14. In vitro pollen germination, pollen tube growth and longevity in some ...

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... Loquat (Eriobotrya japonica Lindl.) is one of the most perspective trees with tasty fruits suitable for commercial production in Iran. However, self-incompatibility of most loquat cultivars makes it necessary to select good pollinizers in breeding and orchard establishment programs. Therefore, studies on pollen ...

  15. Impact of cytomixis on meiosis, pollen viability and pollen size in ...

    Indian Academy of Sciences (India)

    Srinivas

    29. Ashraf M and Gohil R N 1994 Cytology of legumes of Kashmir. Himalaya V. Cytomixis and chromosome migration in. Astragalus subuliformis DC; Nucleus 37 119–122. Bahl J R and Tyagi B R 1988 Cytomixis in pollen mother cells of.

  16. Variations in pollen counts largely explained by climate and weather

    Science.gov (United States)

    Jung, Stephan; Damialis, Athanasios; Estrella, Nicole; Jochner, Susanne; Menzel, Annette

    2017-04-01

    The interaction between climate and vegetation is well studied within phenology. Climatic / weather conditions affect e.g. flowering date, length of vegetation period, start and end of the season and the plant growth. Besides phenological stages also pollen counts can be used to investigate the interaction between climate and vegetation. Pollen emission and distribution is directly influenced by temperature, wind speed, wind direction and humidity/precipitation. The objective of this project is to study daily/sub daily variations in pollen counts of woody and herbaceous plant species along an altitudinal gradient with different climatic conditions during the vegetation period. Measurements of pollen were carried out with three volumetric pollen traps installed at the altitudes 450 m a.s.l (Freising), 700 m a.s.l (Garmisch-Partenkirchen), and 2700 m a.s.l (Schneefernerhaus near Zugspitze) representing gradient from north of Munich towards the highest mountain of Germany. Airborne pollen concentrations were recorded during the years 2014-2015. The altitudinal range of these three stations accompanied by different microclimates ("space for time approach") can be used as proxy for climate change and to assess its impact on pollen counts and thus allergenic risk for human health. For example the pollen season is shortened and pollen amount is reduced at higher sites. For detailed investigations pollen of the species Plantago, Quercus, Poaceae, Cupressaceae, Cyperacea, Betula and Platanus were chosen, because those are found in appropriate quantities. In general, pollen captured in the pollen traps to a certain extent has its origin from the immediate surrounding. Thus, it mirrors local species distribution. But furthermore the distance of pollen transport is also based on (micro-) climatic conditions, land cover and topography. The pollen trap shortly below the summit of Zugspitze (Schneefernerhaus) has an alpine environment without vegetation nearby. Therefore, this

  17. Standardization of different media for in vitro pollen germination of ...

    African Journals Online (AJOL)

    Almond is an important nut crop which, mostly for fruit set, needs the pollination of flowers followed by fertilization. Therefore, pollen viability and its germination capability are essential. To optimize the pollen culture medium of almond and standardization of the best medium, the present study was carried out with 48 different ...

  18. Pollen morphology and variability of Tulipa hungarica Borb

    African Journals Online (AJOL)

    Yomi

    2012-01-10

    Jan 10, 2012 ... tion we investigate the pollen characters. The aim of this study was to investigate Đerdap tulip pollen characters and viability and to discover the best stage of microspore development for androgenesis induction. MATERIALS AND METHODS. Closed flower buds of 5 cm size (Figure 2A) of T. hungarica origi ...

  19. Pollen morphology and diversity in some Nigerian species of ...

    African Journals Online (AJOL)

    Pollen morphology and diversity were studied in five Nigerian species of Jatropha L. (Euphorbiaceae) using acetolysis method and Light Microscopy (LM) with a view to assessing the taxonomic importance of pollen characters in the classification and delimitation of members of genus Jatropha L. Overall results showed that ...

  20. (Cocos nucifera) pollens for removal of Cu (II)

    African Journals Online (AJOL)

    GREGO

    Accepted 21 November, 2006. The ability of undyed and dyed coconut pollens to remove Cu(II) and Zn(II) from single ion solutions ... Key words: Adsorption dynamics, dyed coconut pollen grains, chemisorptions, heavy metals removal. INTRODUCTION ... Metal ion produced and released during industrial acti- vities pose a ...

  1. Evaluation of pollen viability, stigma receptivity and fertilization ...

    African Journals Online (AJOL)

    To provide theoretical basis for artificial pollination in Lagerstroemia indica L., pollen viability and stigma receptivity were tested and the morphological change of stigma was observed. Pollen viability tested by in vitro culture, stigma receptivity examined by benzidine-H2O2 testing and fruit set estimated by field artificial ...

  2. Banana nectar as a medium for testing pollen viability and ...

    African Journals Online (AJOL)

    A quick and reliable method for evaluating pollen quality is essential in a breeding program, especially in a crop such as banana that is characterized by high male and female sterility. In this study the germination and viability of banana pollen was evaluated in a sucrose solution and diluted banana nectar. Twenty banana ...

  3. Sporophytic control of pollen tube growth and guidance in maize

    Science.gov (United States)

    Lausser, Andreas; Kliwer, Irina; Srilunchang, Kanok-orn; Dresselhaus, Thomas

    2010-01-01

    Pollen tube germination, growth, and guidance (progamic phase) culminating in sperm discharge is a multi-stage process including complex interactions between the male gametophyte as well as sporophytic tissues and the female gametophyte (embryo sac), respectively. Inter- and intra-specific crossing barriers in maize and Tripsacum have been studied and a precise description of progamic pollen tube development in maize is reported here. It was found that pollen germination and initial tube growth are rather unspecific, but an early, first crossing barrier was detected before arrival at the transmitting tract. Pollination of maize silks with Tripsacum pollen and incompatible pollination of Ga1s/Ga1s-maize silks with ga1-maize pollen revealed another two incompatibility barriers, namely transmitting tract mistargeting and insufficient growth support. Attraction and growth support by the transmitting tract seem to play key roles for progamic pollen tube growth. After leaving transmitting tracts, pollen tubes have to navigate across the ovule in the ovular cavity. Pollination of an embryo sac-less maize RNAi-line allowed the role of the female gametophyte for pollen tube guidance to be determined in maize. It was found that female gametophyte controlled guidance is restricted to a small region around the micropyle, approximately 50–100 μm in diameter. This area is comparable to the area of influence of previously described ZmEA1-based short-range female gametophyte signalling. In conclusion, the progamic phase is almost completely under sporophytic control in maize. PMID:19926683

  4. Airborne pollen and suicide mortality in Tokyo, 2001-2011.

    Science.gov (United States)

    Stickley, Andrew; Sheng Ng, Chris Fook; Konishi, Shoko; Koyanagi, Ai; Watanabe, Chiho

    2017-05-01

    Prior research has indicated that pollen might be linked to suicide mortality although the few studies that have been undertaken to date have produced conflicting findings and been limited to Western settings. This study examined the association between the level of airborne pollen and suicide mortality in Tokyo, Japan in the period from 2001 to 2011. The daily number of suicide deaths was obtained from the Japanese Ministry of Health, Labour and Welfare, with pollen data being obtained from the Tokyo Metropolitan Institute of Public Health. A time-stratified case-crossover study was performed to examine the association between different levels of pollen concentration and suicide mortality. During the study period there were 5185 male and 2332 female suicides in the pollen season (February to April). For men there was no association between airborne pollen and suicide mortality. For women, compared to when there was no airborne pollen, the same-day (lag 0) pollen level of 30 to Tokyo. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Pollen morphology of the Euphorbiaceae with special reference to taxonomy

    NARCIS (Netherlands)

    Punt, W.

    1962-01-01

    In the present study pollen morphology of the Euphorbeaceae is treated as an additional character in taxonomy. Besides the greater part of the genera occurring in the system of PAX and K. HOFFMANN (1931), most of the genera published after 1931 are studied. The pollen grains have been described with

  6. Modern pollen data from the Canadian Arctic, 1972-1973

    Science.gov (United States)

    Nichols, Harvey; Stolze, Susann

    2017-05-01

    This data descriptor reports results of a 1972-73 baseline study of modern pollen deposition in the Canadian Arctic to originally aid interpretation of Holocene pollen diagrams from that region, especially focussed on the arctic tree-line. The data set is geographically unique due to its extent, and allows the assessment of the effects of modern climate change on northern ecosystems, including fluctuations of the a arctic tree-line. Repeated sampling was conducted along an interior transect at 29 sites from the Boreal Forest to the High Arctic, with five additional coastal sites covering a total distance of 3,200 km. Static pollen samplers captured both local pollen and long-distance pollen wind-blown from the Boreal Forest. Moss and lichen polsters provided multi-year pollen fallout to assess the effectiveness of the static pollen samplers. The local vegetation was recorded at each site. This descriptor provides information on data archived at the World Data Center PANGAEA, which includes spreadsheets detailing site and sample information as well as raw and processed pollen data obtained on over 500 samples.

  7. Cytological evidences of pollen abortion in Ornithogalum caudatum Ait

    African Journals Online (AJOL)

    Administrator

    2011-10-19

    Oct 19, 2011 ... Ornithogalum caudatum Ait exhibits strong physiological adaptability; however, it suffers a serious menace of pollen abortion, as almost no seed is formed in the plants. In the current study, chromosome karyotype of root-tip cells (RTC) during mitosis, and chromosome behavior of pollen mother cells.

  8. Pollen loads and specificity of native pollinators of lowbush blueberry.

    Science.gov (United States)

    Moisan-Deserres, J; Girard, M; Chagnon, M; Fournier, V

    2014-06-01

    The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem.

  9. Borassodendron (Palmae) in the Southeast Asian fossil pollen record

    NARCIS (Netherlands)

    Maloney, B.K.

    2000-01-01

    Borassodendron machadonis pollen occurred throughout the Holocene pollen record of Nong Thale Song Hong, Thailand, until about 4000 BP. It was also present in one sample from Khok Phanom Di, Thailand, and in the Mahakam Delta, Kalimantan, records, but B. machadonis has not been reported from the

  10. Variation in pollen competitive ability in diverse maize lines

    Science.gov (United States)

    Although pollen occupies a small fraction of the angiosperm life cycle, it is of interest for both basic and applied scientific reasons. Seed production depends on a functional male gametophyte achieving fertilization following pollination. Pollen also serves as a vector for ge...

  11. Effects of palm pollen on folliculogenesis process after treatment ...

    African Journals Online (AJOL)

    Abstract. Background and purpose: Palm pollen is a good source of natural antioxidants and has a high level of health benefits and nutritional value. The purpose of this study was to investigate effects of palm pollen on folliculogenesis process after treatment with cyclophosphamide among rats. Materials and Methods: This ...

  12. Pollen diversity, viability and floral structure of some Musa genotypes

    African Journals Online (AJOL)

    This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained from the Musa field germplasm bank at the Faculty of Agriculture & Natural Resources Management farm, Ebonyi State University, Abakaliki. Palynological investigation was carried ...

  13. Determination of pollen viability, germination ratios and morphology ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... regions (Asma, 2000). Flowering and fertilization are critical for fruit set in stone fruits. There are several barriers for fertilization. Poor or malfunctioning pollen production is among these barriers in apricot genotypes. It is known that internal and external factors limit pollen production, viability and germination ...

  14. The pollen-collecting activities of some andrenid bees

    NARCIS (Netherlands)

    Dingemans-Bakels, F.N.

    1972-01-01

    Information about the pollen-collecting activities of bees is usually based on field observations. From such records it cannot be inferred whether pollen was actually collected, as bees, especially the males, also may visit flowers to suck honey or to rest. One may expect more exact data from an

  15. Cytological evidences of pollen abortion in Ornithogalum caudatum Ait

    African Journals Online (AJOL)

    Ornithogalum caudatum Ait exhibits strong physiological adaptability; however, it suffers a serious menace of pollen abortion, as almost no seed is formed in the plants. In the current study, chromosome karyotype of root-tip cells (RTC) during mitosis, and chromosome behavior of pollen mother cells (PMC) during meiosis in ...

  16. Tetrazolium chloride as an indicator of pine pollen germinability

    Science.gov (United States)

    Stanton A. Cook; Robert G. Stanley

    1960-01-01

    Controlled pollination in forest tree breeding requires pollen of known germination capacity. Methods of determining pollen viability include germination in a hanging drop, in a moist atmosphere, on agar gel, or in a sugar solution (DUFFIELD, 1954; DILLON et al., 1957). Errors commonly arise in the application of these techniques because maximum...

  17. Reconstructing Earth's Past Climates: The Hidden Secrets of Pollen

    Science.gov (United States)

    Steele, Adrienne; Warny, Sophie

    2013-01-01

    "Palynology" is the study of fossil pollen and spores, and these tiny grains can provide fundamental information about past climates on Earth. Among their many unique and useful properties, pollen and spores are composed of some of the most chemically resistant organic compounds found in nature. They are also produced in vast quantities…

  18. Rainfall and temperature effects on flowering and pollen productions ...

    African Journals Online (AJOL)

    Production of non-functional pollen by plant reduces effectiveness of pollination. A study was carried out at Cocoa Research Institute of Nigeria, Ibadan to determine the influence of rainfall and temperature on flowering intensity of selected clones of Upper Amazon cocoa (Theobroma cacao), as well as its pollen fertility.

  19. Influence of gamma irradiation on pollen viability, germination ability ...

    African Journals Online (AJOL)

    July 9th, 11th, 15th, 21st and 28th) and pollen age (0th and 1st days) on the pollen viability, germination ability and fruit and seed-set were investigated in pumpkin (Cucurbita moschata Duchesne ex Poir.) and winter squash (Cucurbita maxima ...

  20. rainfall and temperature effects on flowering and pollen productions ...

    African Journals Online (AJOL)

    Production of non-functional pollen by plant reduces effectiveness of pollination. A study was carried out at. Cocoa Research Institute of Nigeria, Ibadan to determine the influence of rainfall and temperature on flowering intensity of selected clones of Upper Amazon cocoa (Theobroma cacao), as well as its pollen fertility.

  1. Pollen tube germination in maize does not require transcriptomic changes

    Science.gov (United States)

    One objective for our group is to better understand the molecular and genetic basis of pollen and pollen tube function, given its critical role in seed production and its importance as a means of gene flow between plant populations. We compared gene expression levels in seedlings...

  2. Differential Effects of Carbohydrates on Arabidopsis Pollen Germination.

    Science.gov (United States)

    Hirsche, Jörg; García Fernández, José M; Stabentheiner, Edith; Großkinsky, Dominik K; Roitsch, Thomas

    2017-04-01

    Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Pollen viability and germination in Jatropha ribifolia and Jatropha ...

    African Journals Online (AJOL)

    The aim of this work is to assess pollen viability using the staining technique and in vitro germination with different concentrations of sucrose in Jatropha ribifolia and Jatropha mollissima, contributing to the knowledge of the reproductive biology and subsidizing their conservation, management and utilization. Pollen viability ...

  4. Signalling and the cytoskeleton of pollen tubes of Papaver rhoeas

    NARCIS (Netherlands)

    Snowman, B.N.; Geitmann, A.; Clarke, S.R.; Staiger, C.J.; Franklin, F.C.H.; Emons, A.M.C.; Franklin-Tong, V.E.

    2000-01-01

    Self-incompatibility (SI) is a genetically controlled system used by many flowering plants to prevent self-pollination, often by the inhibition of pollen tube growth. The importance of cytosolic free calcium, [Ca2+]i, for the regulation of pollen tube growth is well known. We have established, using

  5. Pollen aroma fingerprint of two sunflower (Helianthus annuus L.) genotypes characterized by different pollen colors.

    Science.gov (United States)

    Bertoli, Alessandra; Fambrini, Marco; Doveri, Silvia; Leonardi, Michele; Pugliesi, Claudio; Pistelli, Luisa

    2011-09-01

    Samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (Helianthus annuus L.) and characterized by a different color, i.e., white-cream (WC) and orange (O), were analyzed by the HS-SPME (headspacesolid phase microextraction)/GC/MS technique. This study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. In the GC/MS fingerprints of the WC and O genotypes, 61 and 62 volatile compounds were identified, respectively. Monoterpene hydrocarbons (34% in O vs. 28% in WC) and sesquiterpene hydrocarbons (37% in O vs. 31% in WC) were ubiquitous in all samples analyzed and represented the main chemical classes. α-Pinene (21% in O vs. 20% in WC) and sabinene (11% in O vs. 6% in WC) were the dominant volatiles, but also a full range of aliphatic hydrocarbons and their oxygenated derivatives gave a decisive contribution to the aroma composition (10% in O vs. 12% in WC). In addition, dendrolasin (3% in O vs. 4% in WC) and some minor constituents such as (E)-hex-2-en-1-ol (0.4% in O vs. 0.1% in WC) were pointed out not only for their contribution to the pollen scent, but also for their well-known role in the plant ecological relationships. Having evaluated two pollen morphs with different carotenoid-based colors, the study sought to highlight also the presence of some volatile precursors or derivatives of these pigments in the aroma. However, the pollen aroma of the two selected genotypes made a specific chemical contribution to the sunflower inflorescence scent without any influence on carotenoid derivatives. 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  6. Pollen morphological study in Bordasia bicornis (Malvaceae

    Directory of Open Access Journals (Sweden)

    Graciela Ana Cuadrado

    2003-01-01

    Full Text Available Pollen grains of Bordasia bicornis Krapov. were studied and described with light and scanningelectron microscopy. They showed palynological affinity with species of genus Sida L,therefore they were compared with 39 species of Argentina, Brasil, Colombia. Mexico, SouthAfrica, India, Thailand, Philippines, Texas and Florida U.S.A. Bibliographic and personal datawere used. Affinities in the structure of the exine and height of the spines as well as differencesin apertures number and pores without thicker ring were found

  7. Botany: a record-breaking pollen catapult.

    Science.gov (United States)

    Edwards, Joan; Whitaker, Dwight; Klionsky, Sarah; Laskowski, Marta J

    2005-05-12

    The release of stored elastic energy often drives rapid movements in animal systems, and plant components employing this mechanism should be able to move with similar speed. Here we describe how the flower stamens of the bunchberry dogwood (Cornus canadensis) rely on this principle to catapult pollen into the air as the flower opens explosively. Our high-speed video observations show that the flower opens in less than 0.5 ms--to our knowledge, the fastest movement so far recorded in a plant.

  8. Pollinators, geitonogamy and a model of pollen transfer

    International Nuclear Information System (INIS)

    Di Pasquale, C.

    1995-12-01

    A model of pollination that considers the amount of geitonogamous pollen transfer in different flowers and plants is presented. We assumed in this work self-incompatible plant species and we studied how pollination is affected by different round trips described by pollinator from its nest, taking into account the fraction geitonogamy and the fraction pollen export. A deterministic model and a stochastic model of pollen transfer were developed from which we found that when pollinators describe a uniform sequence (visit the same number of flowers in each plant), individuals receive the maximum outcross pollen or minimum self pollen. That is, from the point of view of fertilization, the optimal number of flowers visited in each plant depends on the number of flowers of the plant, the length of the visit and the number of individuals. (author). 18 refs, 1 fig

  9. STUDY ON POLLEN VIABILITY AS BIOINDICATOR OF AIR QUALITY

    Directory of Open Access Journals (Sweden)

    Florentina ŞTEFLEA

    2012-01-01

    Full Text Available The aim of this research is to estimate the relationship between pollen viability and atmospheric pollution (in polluted and non-polluted conditions. The study was carried out in the city of Timisoara. Two areas, with different intensity of road traffic (very high and absent but all characterized by the presence of the same plant species, were selected. The pollen of herbaceous spontaneous species, arboreal species and a shrub species was used (Robinia pseudacacia, Aesculus x carnea, Catalpa bignonioides, Albizzia julibrissin, Rosa canina, Sambucus nigra, Malva neglecta, Ranunculus acer, Trifolium repens, Cichorium intybus. The pollen of these species was treated with TTC (2, 3, 5 Tryphenil-Tetrazolium-Chloride staining solution and viability was then estimated by light microscopy. The results of the mean pollen viability percentage of the examined species are reported. Pollen viability of herbaceous plants is significantly different between the two environments.

  10. In vitro pollen germination of five citrus species

    International Nuclear Information System (INIS)

    Khan, S.A.; Perveen, A.

    2014-01-01

    The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

  11. [High temperature stres on crop pollen: a review].

    Science.gov (United States)

    Lu, Ming-Hui; Gong, Zhen-Hui; Chen, Ru-Gang; Huang, Wei; Li, Da-Wei

    2009-06-01

    High temperature has already become a noticeable environmental factor for crop production, while plant pollen was the most sensitive organ to high temperature stress. In this paper, the cytological, physiological, and molecular biological studies on the high temperature stress on crop pollen were reviewed, aimed to provide ideas for maintaining high productive ability of crops under high temperature stress. The cytological effects of high temperature on crop pollen included the changes of arrangement patterns of rough endoplasmic reticulum in tapetum cells, the irregularity of vascular bundle sheath cells in connective tissue, and the reduction of vesicle production by dictyosomes of pollen tube, etc.; physiological effects involved the incapacity of timely recovery of Ca2+ homeostasis, the changes of growth regulators contents, and the slowing down of carbohydrate metabolism, etc.; and molecular biological effects manifested in the insufficient induction of heat shock proteins and the inhibition of other functional genes for pollen development, etc.

  12. Pollen irradiation and possible gene transfer in Nicotiana species

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1985-01-01

    Progeny from crosses of Nicotiana langsdorffii with gamma irradiated pollen of Nicotiana alata ‘Crimson Bedder’ showed skewed segregation in the F2 favoring the maternal parent. This is probably not gene transfer in a strict sense, rather just an extreme case of reduced transmission of irradiated...... chromosomes, leading to massive overrepresentation of maternal genes. Gene transfer or mutational loss may explain some anomalous F1 plants. Segregation in the F2 progeny showed the presence of several genes from the irradiated pollen. Crosses of Nicotiana sylvestris, N. plumbaginifolia N. paniculata......, and Petunia parodii with irradiated pollen from N. alata and Petunia hybrida showed no evidence of gene transfer, nor did experiments with irradiated mentor pollen. This indicates that gene transfer with irradiated pollen between non-crossing species or between species giving sterile hybrids is probably...

  13. POLLEN MORPHOLOGY OF CROCUS L.(IRIDACEAE IN BULGARIA

    Directory of Open Access Journals (Sweden)

    UZUNDZHALIEVA KATYA SPASOVA

    2012-06-01

    Full Text Available The pollen of the wild species from the genus Crocus L., spread in Bulgaria has been analyzed. The investigations, made by light microscope show that the pollen of these species is spherical in shape and round in outlines, comparatively big. These morphological characteristics of the pollen of the wild Bulgarian Crocuses define it as a primitive one [6]. The Scanning Electron Microscope investigations, made by Beug [1], established two types of pollen morphology. The results of our investigation led to the conclusion that the same types are also presented in Bulgarian species: – C.biflorus –type, or syncolpate and C.vernus – type, or inaperturate. Eight of the species belong to the first type and only C. pallasii belongs to the second. The pollen of C. reticulatus is with quite unclear aperture – maybe transition to the inaperturate type.

  14. A model to predict the beginning of the pollen season

    DEFF Research Database (Denmark)

    Toldam-Andersen, Torben Bo

    1991-01-01

    In order to predict the beginning of the pollen season, a model comprising the Utah phenoclirnatography Chill Unit (CU) and ASYMCUR-Growing Degree Hour (GDH) submodels were used to predict the first bloom in Alms, Ulttirrs and Berirln. The model relates environmental temperatures to rest completion...... and bud development. As phenologic parameter 14 years of pollen counts were used. The observed datcs for the beginning of the pollen seasons were defined from the pollen counts and compared with the model prediction. The CU and GDH submodels were used as: 1. A fixed day model, using only the GDH model...... for fruit trees are generally applicable, and give a reasonable description of the growth processes of other trees. This type of model can therefore be of value in predicting the start of the pollen season. The predicted dates were generally within 3-5 days of the observed. Finally the possibility of frost...

  15. Pollen morphology of the Onobrychis sect. Heliobrychis in Iran

    Directory of Open Access Journals (Sweden)

    Roya Karamian

    2010-01-01

    Full Text Available Pollen morphology of 20 species belonging to Onobrychis sect. Heliobrychis was studied in Iran. The pollen grains from the herbarium specimens were prepared by acetolysis method and then 8 quantitative characters were studied by light microscopy. Data analysis was carried out by cluster analysis and principal component analysis methods. Pollen grains of the sections were 3-colpate with reticulate ornamentation. Results of the study showed that although the pollen grains in the section were comparatively homogenous, but had a considerable variation in the studied quantitative characters. However among the studied characters, equatorial and polar diameters of pollen grains were the most significant characters. The members of the section can be divided into 3 groups based on these characters.

  16. Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China

    Science.gov (United States)

    Sun, Ai-Qing; Zhang, Chun-Qing; Wu, Cheng-Lai; Gao, Qing-Rong

    2015-01-01

    abstract The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wheat-growing region in 2009. The pollen suspension velocity was 0.3–0.4 m/s. The highest pollen densities were detected in the north, northwest, and south of the pollen source. Pollen was dispersed over distances greater than 245 m in the northwest and northeast directions. At the pollen source center, pollen density decreased with increasing vertical height. In the north of the pollen source, the pollen density from 65 m to 225 m showed a wave-mode decrease with increasing height. The horizontal transport of pollen over longer distances fitted polynomial equations. In the north, the pollen density was highest at 45 m from the pollen source, and decreased with increasing distance. In the northwest, the pollen density showed a double-peak trend. In the northeast, pollen density was highest from 45 m to 125 m from the source. Wind speeds greater than the pollen suspension velocity and the duration of continuous gusts were the main factors affecting pollen dispersal. This information will be useful for determining the spatial isolation distances for hybrid seed production and for the commercial production of transgenic wheat. PMID:25658025

  17. An operational phenological model for numerical pollen prediction

    Science.gov (United States)

    Scheifinger, Helfried

    2010-05-01

    The general prevalence of seasonal allergic rhinitis is estimated to be about 15% in Europe, and still increasing. Pre-emptive measures require both the reliable assessment of production and release of various pollen species and the forecasting of their atmospheric dispersion. For this purpose numerical pollen prediction schemes are being developed by a number of European weather services in order to supplement and improve the qualitative pollen prediction systems by state of the art instruments. Pollen emission is spatially and temporally highly variable throughout the vegetation period and not directly observed, which precludes a straightforward application of dispersion models to simulate pollen transport. Even the beginning and end of flowering, which indicates the time period of potential pollen emission, is not (yet) available in real time. One way to create a proxy for the beginning, the course and the end of the pollen emission is its simulation as function of real time temperature observations. In this work the European phenological data set of the COST725 initiative forms the basis of modelling the beginning of flowering of 15 species, some of which emit allergic pollen. In order to keep the problem as simple as possible for the sake of spatial interpolation, a 3 parameter temperature sum model was implemented in a real time operational procedure, which calculates the spatial distribution of the entry dates for the current day and 24, 48 and 72 hours in advance. As stand alone phenological model and combined with back trajectories it is thought to support the qualitative pollen prediction scheme at the Austrian national weather service. Apart from that it is planned to incorporate it in a numerical pollen dispersion model. More details, open questions and first results of the operation phenological model will be discussed and presented.

  18. Image analysis in automatic system of pollen recognition

    Directory of Open Access Journals (Sweden)

    Piotr Rapiejko

    2012-12-01

    Full Text Available In allergology practice and research, it would be convenient to receive pollen identification and monitoring results in much shorter time than it comes from human identification. Image based analysis is one of the approaches to an automated identification scheme for pollen grain and pattern recognition on such images is widely used as a powerful tool. The goal of such attempt is to provide accurate, fast recognition and classification and counting of pollen grains by computer system for monitoring. The isolated pollen grain are objects extracted from microscopic image by CCD camera and PC computer under proper conditions for further analysis. The algorithms are based on the knowledge from feature vector analysis of estimated parameters calculated from grain characteristics, including morphological features, surface features and other applicable estimated characteristics. Segmentation algorithms specially tailored to pollen object characteristics provide exact descriptions of pollen characteristics (border and internal features already used by human expert. The specific characteristics and its measures are statistically estimated for each object. Some low level statistics for estimated local and global measures of the features establish the feature space. Some special care should be paid on choosing these feature and on constructing the feature space to optimize the number of subspaces for higher recognition rates in low-level classification for type differentiation of pollen grains.The results of estimated parameters of feature vector in low dimension space for some typical pollen types are presented, as well as some effective and fast recognition results of performed experiments for different pollens. The findings show the ewidence of using proper chosen estimators of central and invariant moments (M21, NM2, NM3, NM8 NM9, of tailored characteristics for good enough classification measures (efficiency > 95%, even for low dimensional classifiers

  19. Do pollen donors with fastest-growing pollen tubes sire the best offspring in an anemophilous tree, Betula pendula (Betulaceae)?

    Science.gov (United States)

    Pasonen, H L; Pulkkinen, P; Käpylä, M

    2001-05-01

    The relationship between pollen and progeny performance has been a subject of many studies but the evidence for pollen-tube growth rate as an indicator of progeny fitness is equivocal. We used an anemophilous tree, Betula pendula, to examine the relationship between pollen-tube growth rate and seed and seedling performance. We crossed nine maternal plants with pollen from six pollen donors in a clonal B. pendula seed orchard, measured the pollen-tube growth rates for every cross, and analyzed the performance of the resulting seeds and seedlings. The only significant positive correlation was found between pollen-tube growth rate and seed mass when we controlled for seed number per inflorescence. Using seed mass as a covariate, we found that only maternal parent had a significant effect on the number of seeds per inflorescence, the percentage of germinable and embryonic seeds, and early seedling growth. Both maternal and paternal parents had significant effects on seedling height after 85 d of growth. These results are in concordance with the general view that maternal effects are usually most apparent in seed characters and during early plant growth. This study does not provide strong evidence for the theory of pollen-tube growth rate as an indicator of progeny quality.

  20. Considerations for the preparation of peat samples for palynology, and for the counting of pollen and non-pollen palynomorphs

    NARCIS (Netherlands)

    Chambers, F.M.; van Geel, B.; van der Linden, M.

    2011-01-01

    Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis), which is often limited to the study of pollen and a few easily recognisable

  1. Ion Implantation Hampers Pollen Tube Growth and Disrupts Actin Cytoskeleton Organization in Pollen Tubes of Pinus thunbergii

    International Nuclear Information System (INIS)

    Li Guoping; Yang Lusheng; Huang Qunce; Qin Guangyong

    2008-01-01

    Pollen grains of Pinus thunbergii Parl. (Japanese black pine) were implanted with 30 keV nitrogen ion beams and the effects of nitrogen ion implantation on pollen tube growth in vitro and the organization of actin cytoskeleton in the pollen tube cell were investigated using a confocal laser scanning microscope after fluorescence labeling. Treatment with ion implantation significantly blocked pollen tube growth. Confocal microscopy showed that ion implantation disrupted actin filament cytoskeleton organization in the pollen tube. It was found that there was a distinct correlation between the inhibition of pollen tube growth and the disruption of actin cytoskeleton organization, indicating that an intact actin cytoskeleton is essential for continuous pollen tube elongation in Pinus thunbergii. Although the detailed mechanism for the ion-implantation-induced bioeffect still remains to be elucidated, the present study assumes that the cytoskeleton system in pollen grains may provide a key target in response to ion beam implantation and is involved in mediating certain subsequent cytological changes.

  2. Effect of smoke derivatives on in vitro pollen germination and pollen tube elongation of species from different plant families

    Czech Academy of Sciences Publication Activity Database

    Kumari, A.; Papenfus, H. B.; Kulkarni, M. G.; Pošta, Martin; van Staden, J.

    2015-01-01

    Roč. 17, č. 4 (2015), s. 825-830 ISSN 1435-8603 Institutional support: RVO:61388963 Keywords : karrikinolide * pollen germination * pollen tube growth * smoke-water * trimethylbutenolide Subject RIV: CC - Organic Chemistry Impact factor: 2.216, year: 2015

  3. Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbling mode

    Science.gov (United States)

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP...

  4. Effects of decadal exposure to interacting elevated CO2 and/or O3 on paper birch (Betula papyrifera) reproduction

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Kubiske, Mark E.; Nelson, Neil; Oksanen, Elina; Vapaavuori, Elina; Karnosky, David F.

    2008-01-01

    We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO 2 and/or O 3 on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO 2 increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O 3 also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO 2 + O 3 ) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO 2 may have a largely positive impact on forest tree reproduction and regeneration while elevated O 3 will likely have a negative impact. - In this study, we found that elevated CO 2 enhances and elevated O 3 decreases birch reproduction and early seedling growth

  5. [Study of some characteristics of morphogenesis and germination of Pinus pallasiana D. Don. pollen].

    Science.gov (United States)

    Koba, V P

    2004-01-01

    Investigation of Pinus pallasiana D. Don. pollen morphogenesis in natural forest plantations of the southern slope of the Main ridge of Crimean mountains has been carried out. Some abnormalities of pollen grain and pollen tube formation in the course of pollen germination in vitro are described. The dynamics of developmental abnormalities of P. allasiana male gametophyte is characterized.

  6. Pollen morphology and variability of Tulipa hungarica Borb | Ćalić ...

    African Journals Online (AJOL)

    Pollen morphology of the endemic species Tulipa hungarica Borb was investigated with the goal of diversity protection and conservation. Morphology of pollen was evaluated using a scanning electron microscopy. Pollen grain was monosulcate with perforate striate exine surface. Also, pollen of T. hungarica showed ...

  7. Effects of boron and gibberellic acid on in vitro pollen germination of ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... study the various factors that affect the pollen viability. In vitro pollen germination rates are considered the best indicator of pollen viability (Shivanna et al., 1991). Most researchers advise on the use of sucrose solution as pollen germination media. Besides boric acid, calcium, gibberellic acid, agar, etc. may ...

  8. Untargeted metabolomic analysis of tomato pollen development and heat stress response

    NARCIS (Netherlands)

    Paupière, Marine J.; Müller, Florian; Li, Hanjing; Rieu, Ivo; Tikunov, Yury M.; Visser, Richard G.F.; Bovy, Arnaud G.

    2017-01-01

    Key message: Pollen development metabolomics.Abstract: Developing pollen is among the plant structures most sensitive to high temperatures, and a decrease in pollen viability is often associated with an alteration of metabolite content. Most of the metabolic studies of pollen have focused on a

  9. Pollen morphology of the genus Hydnocarpus (Flacourtiaceae) with notes on related genera

    NARCIS (Netherlands)

    Schaeffer, J.

    1972-01-01

    Pollen grains of 34 species of the genus Hydnocarpus (Flacourtiaceae) are described. Two pollen types, one of which is subdivided in two subtypes, are distinguished. Within Flacourtiaceae the pollen of Hydnocarpus is more or less isolated, but the related genus Chlorocarpa has rather similar pollen.

  10. Characterization of the maize pollen transcriptome: Validation of microarray results using quantitative real-time PCR

    Science.gov (United States)

    Pollen is the primary means of gene flow between plants and plant populations and plays a critical role in seed production. Pollen fitness can be defined as the ability of a particular pollen grain to outcompete other pollen present on the stigma and complete fertilization, thus ...

  11. Impact of ectohumus application in birch and pine nurseries on the presence of soil mites (Acari, Oribatida in particular

    Directory of Open Access Journals (Sweden)

    Klimek Andrzej

    2016-03-01

    Full Text Available Intensively used forest nurseries are characterised by degradation processes that lead to a drop in the quality of seedlings. The main reason of this problem is a decrease in biological soil diversity. Therefore, an attempt of nursery soil enrichment by introducing ectohumus – as compost and fresh litter – from the pine forest was carried out. The research was carried out in 2009–2011 in the Bielawy forest nursery near the city of Toruń, Poland. The objective of the study was to determine the impact of organic fertilisation (compost made up of forest humus and mulching using fresh ectohumus on the density and community composition of Acari mites and on species composition of oribatid mites (Oribatida in the nurseries of silver birch and Scots pine. Mites, especially oribatid mites, were treated as bioindicators of soil biological activity. Research has shown that mulching using fresh ectohumus caused a multiple increase in the density of mites, especially in saprophagous mites Oribatida. Oribatid mites were clearly more numerous in birch cultivation than in that of pine. Overall, 27 species of oribatid mites were found. Mulching resulted in a significant growth in species diversity in both cultivations. The most numerous oribatid mite in the area under the study was Oribatula tibialis. This species was present in all plots and showed clear preference for birch cultivation. Tectocepheus velatus and Oppiella nova, common and known to be present in a variety of environments, were slightly less numerous.

  12. Effects of long-term elevated ultraviolet-B radiation on phytochemicals in the bark of silver birch (Betula pendula)

    Energy Technology Data Exchange (ETDEWEB)

    Tegelberg, R.; Julkunen-Tiitto, R. [Joensuu Univ., Dept. of Biology, Joensuu (Finland); Aphalo, P. J. [Joensuu Univ., Faculty of Forestry, Joensuu (Finland)

    2002-12-01

    The effects of long-term ultraviolet-B radiation on the concentrations of secondary metabolites such as phenolics and terpenoids in the bark of silver birch saplings were studied. The effects of ultraviolet-B on the concentrations of the main soluble sugars such as sucrose, raffinose, and glucose in silver birch stem were also investigated, given that they are involved in the transpiration and allocation of assimilated carbon, and UV-B-induced changes may affect tree growth. Concentrations of sucrose, raffinose and glucose in bark were found to be higher in UV-treated saplings than in saplings grown in ambient radiation, indicating that stem carbohydrate metabolism was changed by long-term exposure to elevated UV radiation. Saplings in elevated UV-A + UV-B radiation treatment and UV-A radiation control treatment had shown significantly increased concentrations of certain UV-absorbing phenolics compared with saplings in ambient radiation. No effect of radiation treatment was observed on non-UV-B-absorbing terpenoids. These observations led to the conclusion that plant parts accumulate specific phenolic UV-filters in response to UV radiation exposure. The accumulation of sugars in the stems of silver birch saplings in response to UV radiation is believed to affect tree growth, possibly because of a reduction of alpha-cellulose content and consequent reduction in cell wall production. 36 refs., 1 tab., 2 figs.

  13. Features of secondary birch young stands in low mountain Pokuttya (Ukrainian Carpathian mts.

    Directory of Open Access Journals (Sweden)

    S. Y. Milevskaya

    2015-06-01

    Full Text Available Forest landscapes of the region during the last 3–5 centuries undergone the profound anthropogenic transformation. Secondary young stands occupy 25% of the total forest area. The problem of derivatives is particularly relevant for the modern forest typology in the Carpathian region. It requires the reflection in its dynamic trends shaping the stands, especially mixed young stands. The aim of our study consisted in getting the knowledge of the structural features of the secondary phytocoenosis of birch young stands in this area.The object of the study was age class I saplings growing in the mountainous part of Pokuttya, particularly in the basin of the Lutshka River. The conceptual basis of our study is the modern dynamic vision that every forest type is a consecutive series of forest plant communities within each type of homogeneous growing conditions. We apply methods of ecological-floristic research of the Brown-Blanke school in the interpretation of the Polish school phytosociology. However we also take into account both syntaxonomy generalizations of the Ukrainian scientists. The actual material comprises the original geobotanical studies with fixation of the vast majority of species in plant communities. Mainly the species having diagnostic value to separate syntaxons were taken into account in the analytical processing. Young forest stands (with the height of 8–12 m and crown cover of 70% together form the trees Betula pendula and B. pubescens. Fairly numerous admixture is formed by trees Alnus incana; besides, there are Fagus sylvatica, Populus tremula, Quercus robur, Padus avium. For dominants, they can be called “grey-alder birch blackberry sedge bracken fern” – Betula pendula+Alnus incana–Rubus caesius–Carex brizoides+Pteridium aquilinum. It is rich in floristic composition of the plant communities. They contain at least 12 species of trees, 3 species of shrubs, 4 species of bushes and 89 species of herbs. Diagnostic

  14. Comparative pollen morphological analysis in the subgenera Passiflora and Decaloba

    Directory of Open Access Journals (Sweden)

    TALIANE L. SOARES

    2017-10-01

    Full Text Available ABSTRACT The genus Passiflora is the most diversified of the Passifloraceae, and its palynology presents wide morphological variability. The objective of the study was to evaluate the pollen morphology of 18 Passiflora species in order to identify informative pollinic characteristics to contribute to the taxonomic classification of the genus. The morphology of the pollen grains and the exine structure were investigated using light microscopy and scanning electron microscopy. Differences in the pollen morphology were found in the studied species, mainly in terms of shape, pollen aperture and ornamentation pattern of the exine. Most of the species belonging to the subgenus Passiflora presented ornamented 6-syncolpate pollen grains with an oblate-spheroidal shape and an exine with large lumens. In the subgenus Decaloba the pollen grains were 6-colporate, 12-colpate and 12-colporate, with subprolate to prolate-spheroidal shape, as well as an exine with smaller lumen size and few ornamented. The pollen morphology of the species of the subgenera Passiflora and Decaloba has shown palynological characteristics that have specific diagnostic value, thus allowing a better understanding of the taxonomy of the genus Passiflora.

  15. Comparative pollen morphological analysis in the subgenera Passiflora and Decaloba.

    Science.gov (United States)

    Soares, Taliane L; Jesus, Onildo N; Souza, Everton H; Rossi, Mônica L; Oliveira, Eder J

    2017-10-16

    The genus Passiflora is the most diversified of the Passifloraceae, and its palynology presents wide morphological variability. The objective of the study was to evaluate the pollen morphology of 18 Passiflora species in order to identify informative pollinic characteristics to contribute to the taxonomic classification of the genus. The morphology of the pollen grains and the exine structure were investigated using light microscopy and scanning electron microscopy. Differences in the pollen morphology were found in the studied species, mainly in terms of shape, pollen aperture and ornamentation pattern of the exine. Most of the species belonging to the subgenus Passiflora presented ornamented 6-syncolpate pollen grains with an oblate-spheroidal shape and an exine with large lumens. In the subgenus Decaloba the pollen grains were 6-colporate, 12-colpate and 12-colporate, with subprolate to prolate-spheroidal shape, as well as an exine with smaller lumen size and few ornamented. The pollen morphology of the species of the subgenera Passiflora and Decaloba has shown palynological characteristics that have specific diagnostic value, thus allowing a better understanding of the taxonomy of the genus Passiflora.

  16. Microwave-Assisted Drying for the Conservation of Honeybee Pollen

    Directory of Open Access Journals (Sweden)

    Angelo Canale

    2016-05-01

    Full Text Available Bee pollen is becoming an important product thanks to its nutritional properties, including a high content of bioactive compounds such as essential amino acids, antioxidants, and vitamins. Fresh bee pollen has a high water content (15%–30% wt %, thus it is a good substrate for microorganisms. Traditional conservation methods include drying in a hot air chamber and/or freezing. These techniques may significantly affect the pollen organoleptic properties and its content of bioactive compounds. Here, a new conservation method, microwave drying, is introduced and investigated. The method implies irradiating the fresh pollen with microwaves under vacuum, in order to reduce the water content without reaching temperatures capable of thermally deteriorating important bioactive compounds. The method was evaluated by taking into account the nutritional properties after the treatment. The analyzed parameters were phenols, flavonoids, with special reference to rutin content, and amino acids. Results showed that microwave drying offers important advantages for the conservation of bee pollen. Irrespective of microwave power and treatment time, phenol and flavonoid content did not vary over untreated fresh pollen. Similarly, rutin content was unaffected by the microwave drying, suggesting that the microwave-assisted drying could be a powerful technology to preserve bioprotective compounds in fresh pollen.

  17. Pollen characters of Firmiana malayana Kostem. (Malvaceae: Sterculoideae) in Malaysia

    Science.gov (United States)

    Amirul-Aiman, A. J.; Noraini, T.; Nurul-Aini, C. A. C.; Idris, S.; Suhaniza, R.

    2018-04-01

    Firmiana malayana also known as "Bullocks eye or Mata Lembu" in Malaysia and can be found along riverbanks and open forests in Peninsular Malaysia and seldom planted in populated areas. The flowers of the Firmiana malayana are vivid orange in colour, on tassels up to 12 cm long. Usually this species will shed its leaves after a dry period and remains bare for six to eight weeks. The objective of this study is to determine the pollen morphological characteristics of the Firmiana malayana in order to add more information on the species under the family of Sterculiaceae in Malaysia. Methods for this study includes acetolysis technique for the pollens and viewed under light microscope and scanning electron microscope. Results shown that the pollens of the species Firmiana malayana appeared to be monad and dyad with tricolporate class with both porate and colpus present. The shape of this species is prolate with P/E index of 1.49. This species was considered as medium-size pollens as the pollens ranges from 26 - 36 µm. The ornamentation of the pollen is reticulate where the ornamentation is network-like pattern formed by exine elements of lumen and murus. Based on the results obtained, pollen morphology is a great tool that can aid in plant identification and classification as well having taxonomic values.

  18. Morphology and viability of castor bean genotypes pollen grains

    Directory of Open Access Journals (Sweden)

    Maria Selma Alves Silva Diamantino

    2016-01-01

    Full Text Available The objective of this work was to characterize the morphology and viability of the pollen of 15 genotypes of castor bean (Ricinus communis L. and to generate information that can assist in the selection of highly promising male parents for future use in genetic improvement programs aimed at producing seeds for oil extraction. Acetolysis and scanning electron microscopy was used to characterize the morphology of the pollen. The viability of the pollen grains was estimated by in vitro germination and colorimetric analysis (acetocarmine 2% and 2, 3, 5-triphenyltetrazolium chloride 1%. For the in vitro germination, pollen grains were grown in 10 types of solidified culture medium consisting of different concentrations of sucrose, boric acid, calcium nitrate, magnesium sulfate and potassium nitrate. The pollen grains had the following characteristics: medium size, isopolar and subspheroidal shape, radial symmetry, circular ambit, 3-colporate, elongated endoapertures, tectate exine and granulated sexine. The acetocarmine dye overestimated pollen viability. The media M5 and M8 were the most efficient at promoting the germination of pollen grains. The studied genotypes had high levels of viability and can therefore be used as male parents in genetic improvement programs.

  19. Therapeutic effect of bee pollens on acute radiation sickness

    International Nuclear Information System (INIS)

    Wang Mingsuo; Huang Chaoqun; Chen Zhen; Huang Meiying; Jiang Ying; Wang Tao

    1997-09-01

    The therapeutic effect of bee pollens on acute radiation sickness were evaluated by observing the changes in the peripheral white blood cell (PWBC) count, the total activity of superoxide dismutase (SOD) and the levels of lipid peroxides (LPO) in sera of the irradiated rats following P.O. administration of bee pollens. It was found that bee pollens could remarkably help irradiated rats recover from radiation-induced injury. The functions of bee pollens might be summarized as follows: (1) Stimulating Proliferation of PWBC. The PWBC count of the bee pollens group showed no significant difference as compared with the normal control group on the 30 th day postirradiation. (2) Enhancing antioxidative effect of clearing free radicals. The total activity of serum SOD in the bee pollens group increased by 6.48% as compared with the normal control group on the 30 th day after irradiation, and the LPO levels i.e. MDA and POV in sera of the irradiated rats decreased by 54.73% and 21.60% respectively. The result suggests that using bee pollens as antiradiation and health-promoting agents in clinical treatment of acute radiation sickness and during radiotherapy of patients with tumors may has certain practical value. (12 refs., 2 figs., 2 tabs.)

  20. On the Relationship between Pollen Size and Genome Size

    Directory of Open Access Journals (Sweden)

    Charles A. Knight

    2010-01-01

    Full Text Available Here we test whether genome size is a predictor of pollen size. If it were, inferences of ancient genome size would be possible using the abundant paleo-palynolgical record. We performed regression analyses across 464 species of pollen width and genome size. We found a significant positive trend. However, regression analysis using phylogentically independent contrasts did not support the correlated evolution of these traits. Instead, a large split between angiosperms and gymnosperms for both pollen width and genome size was revealed. Sister taxa were not more likely to show a positive contrast when compared to deeper nodes. However, significantly more congeneric species had a positive trend than expected by chance. These results may reflect the strong selection pressure for pollen to be small. Also, because pollen grains are not metabolically active when measured, their biology is different than other cells which have been shown to be strongly related to genome size, such as guard cells. Our findings contrast with previously published research. It was our hope that pollen size could be used as a proxy for inferring the genome size of ancient species. However, our results suggest pollen is not a good candidate for such endeavors.

  1. Precipitation signal in pollen rain from tropical forests, South India.

    Science.gov (United States)

    Barboni, D; Bonnefille, R

    2001-04-01

    We have analyzed the pollen content of 51 surface soil samples collected in tropical evergreen and deciduous forests from the Western Ghats of South India sampled along a west to east gradient of decreasing rainfall (between 11 degrees 30-13 degrees 20'N and 75 degrees 30-76 degrees 30'E). Values of mean annual precipitation (Pann, mm/yr) have been calculated at each of the 51 sampling sites from a great number of meteorological stations in South India, using a method of data interpolation based on artificial neural network. Interpolated values at the pollen sites of Pann range from 1200 to 5555mm/yr, while mean temperature of the coldest month (MTCO) remains >15 degrees C and humidity factor (AET/PET, the actual evapotranspiration to potential evapotranspiration ratio) remains also included between 65 and 72%.Results are presented in the form of percentage pollen diagrams where samples are arranged according to increasing values of annual precipitation. They indicate that the climatic signal of rainfall is clearly evidenced by distinct pollen associations. Numerical analyses show that annual precipitation is an important parameter explaining the modern distribution of pollen taxa in this region. Pollen taxa markers of high rainfall (Pann >2500mm/yr) are Mallotus type, Elaeocarpus, Syzygium type, Olea dioica, Gnetum ula, and Hopea type, associated with Ixora type and Caryota. Pollen taxa markers of low rainfall (Pann <2500mm/yr) are Melastomataceae/Combretaceae, Maytenus type, Lagerstroemia and Grewia. The proportions of evergreen taxa and of arboreal taxa vary according to rainfall values. Indeed, when rainfall is <2500mm/yr, percentage of arboreal pollen (AP) is <50% and proportion of evergreen taxa is <20%. When rainfall exceeds 2500mm/yr, AP values average 70%, and proportion of evergreen taxa increases from 60 to 90%. Moreover, a good correlation between precipitation and proportion of evergreen taxa (0.85) presumes that precipitation can be estimated from

  2. Pollen Stoichiometry May Influence Detrital Terrestrial and Aquatic Food Webs

    Directory of Open Access Journals (Sweden)

    Michał Filipiak

    2016-12-01

    Full Text Available Pollen rains may temporally mitigate nutritional limitations experienced by terrestrial and aquatic detritivores by supplying stoichiometrically balanced food during periods of detritivore growth and development (spring-summer. This may affect the functioning of food webs and thus influence fundamental processes, e.g., by enabling fungi to decompose nutritionally scarce litter. Nutritional limitation may be studied within the framework of ecological stoichiometry by comparing the stoichiometric mismatches experienced by organisms feeding on various foods. To this end, the elemental compositions of pine pollen, litter and detritivores (fungi, protozoans, worms, insects, mites, millipedes, isopods and slugs were compared, as were the stoichiometric mismatches experienced by the detritivores feeding on litter and pollen. Additionally, the contribution of pollen to the nutrient flow from the land to aquatic ecosystems was estimated through a literature review. Compared to litter, pine pollen is a stoichiometrically well-balanced food source in terms of its C:N:P ratio but also because of its high concentrations of K, S and Cu and its favorable Zn:Fe ratio. This characteristic is especially suitable to fungi, which may be responsible for the redistribution of pollen-derived nutrients in food webs, particularly aquatic ones. Pollen rains of various plant species act as temporal pulses of nutrients that are rapidly utilized and quickly introduced into the food web, so calculations of annual biomass input may be misleading. Pollen is an easily available, digestible and nutritious food for fungi, bacteria, protozoans and various groups of invertebrates, which suggests that pollen plays an important role in within- and cross-ecosystem nutrient cycling.

  3. Impact of cytomixis on meiosis, pollen viability and pollen size in ...

    Indian Academy of Sciences (India)

    Srinivas

    mother cells of Medicago sativa L.; J. Heredity 94 512–516. Bhat T A, Parveen S and Khan A H 2006 MMS-induced cytomixis in pollen mother cells of broad bean (Vicia faba L.); Turk. J. Bot. 30 273–279. Bione N C P, Pagliarini M S and de Toledo J F F 2000 Meiotic behavior of several Brazilian soybean varieties; Genet.

  4. Variation patterns of pollen production in palm flowers

    DEFF Research Database (Denmark)

    Alapetite, Elodie; Barfod, Anders; Albert, Beatrice

    2016-01-01

    pollen production and stamen number has never been so far investigated. The diversity in stamen number observed among palms species and genera provides an ideal case study to test for such a correlation, taking into account phylogenetic constraints. Based on a survey of flowers from 82 species...... representative of the various palm tribes and compared it to stamen number, we show that pollen production in palms ranges from hundreds to millions grains. There is a relationship between stamen number and pollen production in our sampling, particularly in Coryphoideae and Arecoideae where there is a tendency...

  5. Ubisch bodies and pollen ontogeny in Oxalis articulata Savigny.

    Science.gov (United States)

    Rosenfeldt, Sonia; Galati, Beatriz G

    2005-12-01

    The correlation between the ontogeny of Ubisch bodies and pollen development in Oxalis articulata was studied with Transmission Electron Microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells are related to Ubisch bodies, sporopollenin and pollen-kitt formation. The pro-orbicules have the appearance of lipid globuli and their formation is related to the endoplasmic reticulum of rough type (ERr). The lipid globules or pro-orbicules disappear in the mature Ubisch bodies, and the places that they occupied remain free of contents or with pollen-kitt.

  6. Mathematical Modeling of the High Temperature Treatment of Birch in a Prototype Furnace

    Directory of Open Access Journals (Sweden)

    Duygu Kocaefe

    2013-01-01

    Full Text Available In recent years, various wood modification technologies have been commercialized as alternatives to the traditional chemical treatments for wood preservation. The high temperature heat treatment of wood is one of these commercially viable and environmentally friendly alternative wood modification technologies. During this treatment, wood is heated to temperatures above 200°C by contacting it with hot gas. The chemical structure of wood changes leading to increased dimensional stability and resistance to microorganisms. Wood darkens making it aesthetically more attractive. However, it loses some of its elasticity. Therefore, the high temperature heat treatment has to be optimized for each species and each technology. The mathematical modeling is an important tool for optimization. It can also be used as a powerful tool for furnace modification and design. A reliable and predictive model was developed to simulate numerically the heat treatment process. Heat treatment experiments were carried out in the prototype furnace of the University of Quebec at Chicoutimi. The model was validated by comparing the predictions with the experimental data. In this paper, the results of the model applied to birch heat treatment are presented. The model predictions are in good agreement with the data.

  7. The formation of pollen in male flowers and yearly atmospheric pollen counts of Cryptomeria japonica in the following year

    Directory of Open Access Journals (Sweden)

    Hideaki Taira

    1998-01-01

    Full Text Available Prediction of yearly atmospheric pollen counts is a very important component in the prevention of allergenic symptoms. We investigated the relationship between atomspheric pollen counts and the formation of male flowers of Cryptomeriajaponica D. Don (C. japonica. An atmospheric pollen survey of C. japonica was conducted from 1983 to 1996 using a Durham’s sampler. A regression analysis was performed between the total pollen count and July temperature in previous years. The atmospheric pollen counts of C. japonica had a high positive correlation with the mean temperature in July of the previous year. However, the predicted using average mean July temperature records of the previous year were insufficient, especially in years following high pollen count. In experimental conditions, using 60 C. japonica trees in pots, the formation of male flowers was shown to increase with a rise in incubation temperature. In a forest of C. japonica, our results showed that the length and weight of new needle growth from old needles, which produced many flowers in the previous year, were shorter and lighter, respectively. These aerobiological and plant physiological studies provide evidence that a smaller number of pollen counts are a common result in a year following one in which many male flowers are produced, even if the mean July temperature of that year was high.

  8. Proteomics identification of differentially expressed proteins associated with pollen germination and tube growth reveals characteristics of germinated Oryza sativa pollen.

    Science.gov (United States)

    Dai, Shaojun; Chen, Taotao; Chong, Kang; Xue, Yongbiao; Liu, Siqi; Wang, Tai

    2007-02-01

    Mature pollen from most plant species is metabolically quiescent; however, after pollination, it germinates quickly and gives rise to a pollen tube to transport sperms into the embryo sac. Because methods for collecting a large amount of in vitro germinated pollen grains for transcriptomics and proteomics studies from model plants of Arabidopsis and rice are not available, molecular information about the germination developmental process is lacking. Here we describe a method for obtaining a large quantity of in vitro germinating rice pollen for proteomics study. Two-dimensional electrophoresis of approximately 2300 protein spots revealed 186 that were differentially expressed in mature and germinated pollen. Most showed a changed level of expression, and only 66 appeared to be specific to developmental stages. Furthermore 160 differentially expressed protein spots were identified on mass spectrometry to match 120 diverse protein species. These proteins involve different cellular and metabolic processes with obvious functional skew toward wall metabolism, protein synthesis and degradation, cytoskeleton dynamics, and carbohydrate/energy metabolism. Wall metabolism-related proteins are prominently featured in the differentially expressed proteins and the pollen proteome as compared with rice sporophytic proteomes. Our study also revealed multiple isoforms and differential expression patterns between isoforms of a protein. These results provide novel insights into pollen function specialization.

  9. Grass pollen immunotherapy: where are we now.

    Science.gov (United States)

    Würtzen, Peter A; Gupta, Shashank; Brand, Stephanie; Andersen, Peter S

    2016-01-01

    During allergen immunotherapy (AIT), the allergic patient is exposed to the disease-inducing antigens (allergens) in order to induce clinical and immunological tolerance and obtain disease modification. Large trials of grass AIT with highly standardized subcutaneous and sublingual tablet vaccines have been conducted to document the clinical effect. Induction of blocking antibodies as well as changes in the balance between T-cell phenotypes, including induction of regulatory T-cell subtypes, have been demonstrated for both treatment types. These observations increase the understanding of the immunological mechanism behind the clinical effect and may make it possible to use the immunological changes as biomarkers of clinical effect. The current review describes the recent mechanistic findings for subcutaneous immunotherapy and sublingual immunotherapy/tablet treatment and discusses how the observed immunological changes translate into a scientific foundation for the observed clinical effects of grass pollen immunotherapy and lead to new treatment strategies for grass AIT.

  10. Automated DNA extraction from pollen in honey.

    Science.gov (United States)

    Guertler, Patrick; Eicheldinger, Adelina; Muschler, Paul; Goerlich, Ottmar; Busch, Ulrich

    2014-04-15

    In recent years, honey has become subject of DNA analysis due to potential risks evoked by microorganisms, allergens or genetically modified organisms. However, so far, only a few DNA extraction procedures are available, mostly time-consuming and laborious. Therefore, we developed an automated DNA extraction method from pollen in honey based on a CTAB buffer-based DNA extraction using the Maxwell 16 instrument and the Maxwell 16 FFS Nucleic Acid Extraction System, Custom-Kit. We altered several components and extraction parameters and compared the optimised method with a manual CTAB buffer-based DNA isolation method. The automated DNA extraction was faster and resulted in higher DNA yield and sufficient DNA purity. Real-time PCR results obtained after automated DNA extraction are comparable to results after manual DNA extraction. No PCR inhibition was observed. The applicability of this method was further successfully confirmed by analysis of different routine honey samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

    International Nuclear Information System (INIS)

    Berenbrock, C.; Kjelstrom, L.C.

    1997-01-01

    Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed

  12. Regulatory networks in pollen development under cold stress

    Directory of Open Access Journals (Sweden)

    Kamal Dev Sharma

    2016-03-01

    Full Text Available Cold stress modifies anthers’ metabolic pathways to induce pollen sterility. Cold-tolerant plants, unlike the susceptible ones, produce high proportion of viable pollen. Anthers in susceptible plants, when exposed to cold stress, increase abscisic acid (ABA metabolism and reduce ABA catabolism. Increased ABA negatively regulates expression of tapetum cell wall bound invertase and monosaccharide transport genes resulting in distorted carbohydrate pool in anther. Cold-stress also reduces endogenous levels of the bioactive gibberellins (GAs, GA4 and GA7, in susceptible anthers by repression of the GA biosynthesis genes. Here we discuss recent findings on mechanisms of cold susceptibility in anthers which determine pollen sterility. We also discuss differences in regulatory pathways between cold-stressed anthers of susceptible and tolerant plants that decide pollen sterility or viability.

  13. Pollen morphology of European bladderworts (Utricularia L., Lentibulariaceae)

    Czech Academy of Sciences Publication Activity Database

    Beretta, M.; Rodondi, G.; Adamec, Lubomír; Andreis, C.

    2014-01-01

    Roč. 205, č. 1 (2014), s. 22-30 ISSN 0034-6667 Institutional support: RVO:67985939 Keywords : Utricularia * pollen morphology * determination key Subject RIV: EF - Botanics Impact factor: 1.940, year: 2014

  14. Pollen genetic markers for detection of mutagens in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Nilan, R.A.; Rosichan, J.L.; Arenaz, P.; Hodgdon, A.L.; Kleinhofs, A.

    1980-01-01

    To utilize and exploit pollen for in situ mutagen monitoring, screening and toxicology, the range of genetic traits in pollen must be identified and analyzed. To be useful for the development of mutagen detection systems proteins should be: (1) activity stainable or immunologically identifiable in the pollen, (2) the products of one to three loci; and (3) gametophytic and nuclear in origin. Several proteins, including alcohol dehydrogenase in maize, which meet these criteria are discussed. The waxy locus in barley and maize which controls starch deposition for pollen screening and mutant detection. Thirty waxy mutant lines, induced by sodium azide and gamma-rays are characterized for spontaneous and induced reversion frequencies, allelism, karyotype, amylose content, and UDPglucose glucosyltransferase (waxy gene product) activity. Twelve mutant alleles are being mapped by recombinant frequencies.

  15. Change in Ragweed Pollen Season, 1995-2015

    Data.gov (United States)

    U.S. Environmental Protection Agency — This figure shows how the length of ragweed pollen season changed at 11 locations in the central United States and Canada between 1995 and 2015. Data were provided...

  16. Assessment of Bollgard II cotton pollen mediated transgenes flow to ...

    African Journals Online (AJOL)

    Assessment of Bollgard II cotton pollen mediated transgenes flow to conventional cotton in the farming conditions of Burkina Faso. Bourgou Larbouga, Sanfo Denys, Tiemtore C Bernard, Traore Oula, Sanou Jacob, Traore Karim ...

  17. Incidence of atmospheric pollen in the Pretoria Witwatersrand ...

    African Journals Online (AJOL)

    -Witwatersrand-Vereeniging region (PWV) since 1987. Two Burkard 7-day recording traps were used in Johannesburg and Pretoria, and 11 gravity samplers were installed at various sites in the PWV. An analysis of the pollen component and ...

  18. Pollen analyses of Pleistocene hyaena coprolites from Montenegro and Serbia

    Directory of Open Access Journals (Sweden)

    Argant Jacqueline

    2007-01-01

    Full Text Available The results of pollen analyses of hyaena coprolites from the Early Pleistocene cave of Trlica in northern Montenegro and the Late Pleistocene cave of Baranica in southeast Serbia are described. The Early Pleistocene Pachycrocuta brevirostris, and the Late Pleistocene Crocuta spelaea are coprolite-producing species. Although the pollen concentration was rather low, the presented analyses add considerably to the much-needed knowledge of the vegetation of the central Balkans during the Pleistocene. Pollen extracted from a coprolite from the Baranica cave indicates an open landscape with the presence of steppe taxa, which is in accordance with the recorded conditions and faunal remains. Pollen analysis of the Early Pleistocene samples from Trlica indicate fresh and temperate humid climatic conditions, as well as the co-existence of several biotopes which formed a mosaic landscape in the vicinity of the cave.

  19. Do urban canyons influence street level grass pollen concentrations?

    DEFF Research Database (Denmark)

    Hertel, Ole; Gerorge Peel, Robert; Kennedy, Roy

    2014-01-01

    In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre...... street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found...... source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were...

  20. Microsporogenesis in vivo and in vitro. Autofluorescence of pollen wall of Lilium and changes in pollen wall of Gasteria in Lilium anther

    OpenAIRE

    M. T. Willemse

    2014-01-01

    Autafluarescence of the pollen wall of Lilium shows a correlative change with its development. When the pollen of Gasteria is injected into the anther of Lilium, it exhibits almost the same characteristics of wall autofluorescence as those of Lilium. Only the last stages of wall development are dissimilar. During this period the pollenkitt sticks to the pollen wall in Lilium only. The conclusion is that in the exine of Gasteria pollen, in contact with the locular fluid of Lilium, polymerizati...

  1. Has Pollination Mode Shaped the Evolution of Ficus Pollen?

    Science.gov (United States)

    Wang, Gang; Chen, Jin; Li, Zong-Bo; Zhang, Feng-Ping; Yang, Da-Rong

    2014-01-01

    Background The extent to which co-evolutionary processes shape morphological traits is one of the most fascinating topics in evolutionary biology. Both passive and active pollination modes coexist in the fig tree (Ficus, Moraceae) and fig wasp (Agaonidae, Hymenoptera) mutualism. This classic obligate relationship that is about 75 million years old provides an ideal system to consider the role of pollination mode shifts on pollen evolution. Methods and Main Findings Twenty-five fig species, which cover all six Ficus subgenera, and are native to the Xishuangbanna region of southwest China, were used to investigate pollen morphology with scanning electron microscope (SEM). Pollination mode was identified by the Anther/Ovule ratio in each species. Phylogenetic free regression and a correlated evolution test between binary traits were conducted based on a strong phylogenetic tree. Seventeen of the 25 fig species were actively pollinated and eight species were passively pollinated. Three pollen shape types and three kinds of exine ornamentation were recognized among these species. Pollen grains with ellipsoid shape and rugulate ornamentation were dominant. Ellipsoid pollen occurred in all 17 species of actively pollinated figs, while for the passively pollinated species, two obtuse end shapes were identified: cylinder and sphere shapes were identified in six of the eight species. All passively pollinated figs presented rugulate ornamentation, while for actively pollinated species, the smoother types - psilate and granulate-rugulate ornamentations - accounted for just five and two among the 17 species, respectively. The relationship between pollen shape and pollination mode was shown by both the phylogenetic free regression and the correlated evolution tests. Conclusions Three pollen shape and ornamentation types were found in Ficus, which show characteristics related to passive or active pollination mode. Thus, the pollen shape is very likely shaped by pollination mode

  2. Pollen : a biological indicator for climate, geographical, and soil conditions

    OpenAIRE

    Attard, Everaldo; Callus, Joseph

    2008-01-01

    The monitoring of pollen concentrations over time, delivers detailed information on droughts and desertification in the monitored area. The change in pollen concentration of typical plant species for the specific area over time makes it possible to predict its status such as extinction and overpopulation. Therefore risk analysis on the future development of the surrounding ecosystems are possible Such systems include the Mediterranean maquis, vegetation of dunes or wetlands, as well as ext...

  3. [Skin sensitization to pollens in Morocco. Multicenter study].

    Science.gov (United States)

    Yazidi, A A; Nejjari, C; Bartal, M

    2001-10-01

    The objective of this study was to determine the prevalence of skin sensitization to certain pollens in some regions of Morocco. This multicentric study involving 10 centres included a consecutive series of 640 patients consulting for the first time between february and april 1998 for asthma and/or rhinitis and/or conjunctivitis. Skin prick tests (SPT) were performed with stallerpointes (Stallergenes) and interpreted according to standard procedures. Pollinosis was ascertained when SPT was positive to one or more pollens. Epi-Info was used to analyze the data. SPT were positive in 75.9% and prevalence of sensitization to pollens was equal to 28% (179 cases). It ranked second after house dust mites (63%), olive, 5 grass, cupressus, parietaria and corylus sensitization were encountered in 19.8%, 10.9%, 3.8%, 1.7% and 1.3% respectively. Prevalence of sensitization to pollens didn't vary significatively according to age: 25.4% in females versus 31.1% in males (p = 0.13). Prevalence of pollen sensitization was 26.6% in case of asthma versus 30.9% in non asthmatics patients (p = 0.30), 30.1% in case of rhinitis versus 16.9% in non rhinitics (p = 0.009), 36.4% in case of conjunctivitis versus 22.7% in case without conjunctivitis (p Tanger (27.3%), Rabat (21.8%), Safi (21.3%), Casablanca (11.6%) and El Jadida (10%). The prevalence was up to 84.3% when symptoms were predominant in spring versus 16.8% in other seasons (p < 0.0001). Thus, although SPT did not include numerous other pollens, olive pollinosis seems to be prevalent in Morocco, followed by allergy to grass pollen. Such studies need to be carried out in line with pollen count.

  4. How far can we simplify in vitro diagnostics for grass pollen allergy?: A study with 17 whole pollen extracts and purified natural and recombinant major allergens

    NARCIS (Netherlands)

    van Ree, R.; van Leeuwen, W. A.; Aalberse, R. C.

    1998-01-01

    BACKGROUND: Current diagnostics for grass pollen allergy are composed of mixtures of pollen of different grass species. Their complex composition hampers accurate standardization. OBJECTIVE: The aim of the study was to investigate whether mixtures of grass pollen extracts can be replaced by a single

  5. Temperature sensitivity of a numerical pollen forecast model

    Science.gov (United States)

    Scheifinger, Helfried; Meran, Ingrid; Szabo, Barbara; Gallaun, Heinz; Natali, Stefano; Mantovani, Simone

    2016-04-01

    Allergic rhinitis has become a global health problem especially affecting children and adolescence. Timely and reliable warning before an increase of the atmospheric pollen concentration means a substantial support for physicians and allergy suffers. Recently developed numerical pollen forecast models have become means to support the pollen forecast service, which however still require refinement. One of the problem areas concerns the correct timing of the beginning and end of the flowering period of the species under consideration, which is identical with the period of possible pollen emission. Both are governed essentially by the temperature accumulated before the entry of flowering and during flowering. Phenological models are sensitive to a bias of the temperature. A mean bias of -1°C of the input temperature can shift the entry date of a phenological phase for about a week into the future. A bias of such an order of magnitude is still possible in case of numerical weather forecast models. If the assimilation of additional temperature information (e.g. ground measurements as well as satellite-retrieved air / surface temperature fields) is able to reduce such systematic temperature deviations, the precision of the timing of phenological entry dates might be enhanced. With a number of sensitivity experiments the effect of a possible temperature bias on the modelled phenology and the pollen concentration in the atmosphere is determined. The actual bias of the ECMWF IFS 2 m temperature will also be calculated and its effect on the numerical pollen forecast procedure presented.

  6. How does pollen versus seed dispersal affect niche evolution?

    Science.gov (United States)

    Aguilée, Robin; Shaw, Frank H; Rousset, François; Shaw, Ruth G; Ronce, Ophélie

    2013-03-01

    In heterogeneous landscapes, the genetic and demographic consequences of dispersal influence the evolution of niche width. Unless pollen is limiting, pollen dispersal does not contribute directly to population growth. However, by disrupting local adaptation, it indirectly affects population dynamics. We compare the effect of pollen versus seed dispersal on the evolution of niche width in heterogeneous habitats, explicitly considering the feedback between maladaptation and demography. We consider two scenarios: the secondary contact of two subpopulations, in distinct, formerly isolated habitats, and the colonization of an empty habitat with dispersal between the new and ancestral habitat. With an analytical model, we identify critical levels of genetic variance leading to niche contraction (secondary contact scenario), or expansion (new habitat scenario). We confront these predictions with simulations where the genetic variance freely evolves. Niche contraction occurs when habitats are very different. It is faster as total gene flow increases or as pollen predominates in overall gene flow. Niche expansion occurs when habitat heterogeneity is not too high. Seed dispersal accelerates it, whereas pollen dispersal tends to retard it. In both scenarios very high seed dispersal leads to extinction. Overall, our results predict a wider niche for species dispersing seeds more than pollen. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  7. Influence of wind direction on pollen concentration in the atmosphere

    Science.gov (United States)

    Silva Palacios, I.; Tormo Molina, R.; Muñoz Rodríguez, A. F.

    The daily pollen concentration in the atmosphere of Badajoz (SW Spain) was analysed over a 6-year period (1993-1998) using a volumetric aerobiological trap. The results for the main pollination period are compared with the number of hours of wind each day in the four quadrants: 1 (NE), 2 (SE), 3 (SW) and 4 (NW). The pollen source distribution allowed 16 pollen types to be analysed as a function of their distribution in the four quadrants with respect to the location of the trap. Four of them correspond to species growing in an irrigated farmland environment (Amaranthaceae-Chenopodiaceae, Plantago, Scirpus, and Typha), five to riparian and woodland species (Salix, Fraxinus, Alnus, Populus, and Eucalyptus), four to urban ornamentals (Ulmus, Arecaceae, Cupressaceae, and Casuarina), and three which include the most frequent pollen grains of widely distributed species (Poaceae, Quercus, and Olea). The results show that the distribution of the sources and the wind direction play a very major role in determining the pollen concentration in the atmosphere when these sources are located in certain quadrants, and that the widely distributed pollen sources show no relationship with wind direction. In some years the values of the correlations were not maintained, which leads one to presume that, in order to draw significant conclusions and establish clear patterns of the influence of wind direction, a continuous and more prolonged study will be required.

  8. Pollen fall-out from a tropical vegetation mosaic.

    Science.gov (United States)

    Walker; Sun

    2000-07-01

    Pollen fall-out into 60 Oldfield traps set in 11 localities and a variety of vegetational contexts on an upland in tropical northeast Australia, range from 0.5k to 20k (mean 3.5k)grcm(-2)a(-1). The ranges attributable to the four major vegetation types in which the traps were situated overlap to such an extent as would make it virtually impossible to allocate an 'unknown' pollen count to a vegetation type on the basis of total pollen influx alone. Nevertheless, the composition of the pollen clearly differs according to the vegetation in which it is trapped and the amounts of other vegetation types within at least 100m. Substantial variations in catches from closely placed traps suggest the influence of very local site, including meteorological, conditions on the results. Pollen is carried between vegetation types, much less far from rainforest than from sclerophyll forest and woodland, regrowth scrub or herbaceous vegetation, but there is no numerically significant ubiquitous 'background' fall-out in the region. The data impose some constraints on the interpretation of fossil pollen spectra but also potentially permit a greater precision in some aspects of such applications.

  9. Securing maximum diversity of Non Pollen Palynomorphs in palynological samples

    DEFF Research Database (Denmark)

    Enevold, Renée; Odgaard, Bent Vad

    2015-01-01

    Palynology is no longer synonymous with analysis of pollen with the addition of a few fern spores. A wide range of Non Pollen Palynomorphs are now described and are potential palaeoenvironmental proxies in the palynological surveys. The contribution of NPP’s has proven important to the interpreta......Palynology is no longer synonymous with analysis of pollen with the addition of a few fern spores. A wide range of Non Pollen Palynomorphs are now described and are potential palaeoenvironmental proxies in the palynological surveys. The contribution of NPP’s has proven important.......g. Schulz & Shumilovskikh 2013). Increasingly it has become customary for palynologists to quantify at least some of the NPP’s appearing on the pollen slides (e.g. Strother et al. 2015, Odgaard 1994). Are these samples representative of the initial NPP assemblages? The usual sample preparation method...... for pollen analysis is based on acetylization (Erdtman 1969) and HF-treatment which are of variable destructiveness to the NPP’s. Some NPP’s might completely vanish and the prepared sample might hold less NPP diversity than the initial NPP assemblage. Consequently, it may be advisable to consider...

  10. Localization of actin in pollen tubes of Ornithogalum virens L.

    Directory of Open Access Journals (Sweden)

    Małgorzata Stępka

    2014-01-01

    Full Text Available The germinating pollen grain (in vivo on the stigma or in vitro in germination medium forms a pollen tube which transports the vegetative nucleus and generative cell/two sperm cells participating in the process of double fertilization. The growth of the tube and the transport of organelles and the cells occur due to two major motor systems existing in the pollen tubes of higher plants: the tubuline-dynein/kinesin and the actin-myosin system. In pollen tubes of Ornithogalum virens the actin filaments were labelled with TRITC-phalloidin (2 µg/ml in the PIPES buffer and the 10% sucrose, without the fixative and DMSO. Omission of the fixative and permeabilizing agent (DMSO allowed better preservation of the structure, and the "fluorescence" of actin was observed in living pollen tubes. Observations in CLSM (confocal laser scanning microscope showed that actin is distributed in the vicinity of the cell membrane. This could support the view that actin filaments and the plasmalemma form the pollen tube cortex along which the cytoplasmic movement of organelles, and cell transport occurs.

  11. Nursing protects honeybee larvae from secondary metabolites of pollen

    Science.gov (United States)

    Lucchetti, Matteo A.; Kilchenmann, Verena; Glauser, Gaetan; Praz, Christophe

    2018-01-01

    The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen of Echium vulgare on honeybee adults and larvae. Echimidine, a PA present in E. vulgare pollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen. PMID:29563265

  12. Factors affecting quantity of pollen dispersal of spray cut chrysanthemum (Chrysanthemum morifolium).

    Science.gov (United States)

    Wang, Xiao-Guang; Wang, Hai-Bin; Chen, Fa-Di; Jiang, Jia-Fu; Fang, Wei-Min; Liao, Yuan; Teng, Nian-Jun

    2014-01-06

    Spray cut chrysanthemum is a vital flower with high ornamental value and popularity in the world. However, the excessive quantity of pollen dispersal of most spray cut chrysanthemum is an adverse factor during its flowering stage, and can significantly reduce its ornamental value and quickly shorten its vase life. More seriously, excessive pollen grains in the air are usually harmful to people, especially for those with pollen allergies. Therefore, in order to obtain some valuable information for developing spray cut chrysanthemum with less-dispersed or non-dispersed pollen in the future breeding programs, we here investigated the factors affecting quantity of pollen dispersal of spray cut chrysanthemum with four cultivars, i.e. 'Qx-097', 'Noa', 'Qx-115', and 'Kingfisher', that have different quantity of pollen dispersal. 'Qx-097' with high quantity of pollen dispersal has 819 pollen grains per anther, 196.4 disk florets per inflorescence and over 800,000 pollen grains per inflorescence. The corresponding data for 'Noa' with low quantity of pollen dispersal are 406, 175.4 and over 350,000, respectively; and 219, 144.2 and nearly 160,000 for 'Qx-115' without pollen dispersal, respectively. 'Kingfisher' without pollen dispersal has 202.8 disk florets per inflorescence, but its anther has no pollen grains. In addition, 'Qx-097' has a very high degree of anther cracking that nearly causes a complete dispersal of pollen grains from its anthers. 'Noa' has a moderate degree of anther cracking, and pollen grains in its anthers are not completely dispersed. However, the anthers of 'Qx-115' and 'Kingfisher' do not crack at all. Furthermore, microsporogenesis and pollen development are normal in 'Qx-097', whereas many microspores or pollen degenerate in 'Noa', most of them abort in 'Qx-115', and all of them degrade in 'Kingfisher'. These results suggest that quantity of pollen dispersal in spray cut chrysanthemum are mainly determined by pollen quantity per anther, and

  13. Viable suspensions of maize (Zea mays L.) pollen with exogenous DNA

    Energy Technology Data Exchange (ETDEWEB)

    Broglia, M. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Innovazione

    1996-12-01

    A viable suspension of maize pollen in aqueous medium containing exogenous DNA would be a suitable tool in attempting maize genetic transformation via pollen grains by different techniques. In this work the effects of addition of DNA to hypertonic aqueous media able to preserve maize pollen viability were investigated. An almost total loss of viability was found when pollen was incubated with native DNA in water or sucrose medium due to the immediate sticking of DNA on the pollen wall. Calcium in the incubation medium avoided DNA sticking preserving pollen fertilization ability. Pre-washing of pollen in hypertonic sucrose solution was proved to remove DNA binding components from the pollen wall. PEG 20%, that is known to inhibit pollen, and silk nucleases, was also used instead of sucrose, without any reduction in the seed-set yields.

  14. Types of Pollen Dispersal Units in Orchids, and their Consequences for Germination and Fertilization

    Science.gov (United States)

    Pacini, Ettore; Hesse, Michael

    2002-01-01

    The various pollen dispersal units (PDU) found in orchids are discussed together with possible evolutionary trends and the consequences for germination and fertilization. Orchids with monad and tetrad pollen form more complex dispersal units by means of pollenkitt, elastoviscin, a callosic wall, common walls or a combination of these. Evolutionary trends include (1) from pollenkitt to elastoviscin; (2) from monad to tetrads and multiples of tetrads; (3) from partially dehydrated (30 %) pollen; and (4) from monad pollen to PDUs with many pollen grains. The biological consequences concern both male and female reproductive systems. Some features of the male side are present in all orchids irrespective of the pollen dispersal unit, whereas other characters are found only in orchids with pollinia; the same applies for the female counterpart. Pollen grains of orchids with pollinia germinate at least 24 h after pollination because the pollen grains/tetrads must swell and make space for the growth of pollen tubes. PMID:12102520

  15. Gametophytic Pollen Tube Guidance: Attractant Peptides, Gametic Controls, and Receptors1[OPEN

    Science.gov (United States)

    2017-01-01

    Pollen tube guidance in flowering plants is a unique and critical process for successful sexual reproduction. The pollen tube that grows from pollen, which is the male gametophyte, precisely navigates to the embryo sac, which is the female gametophyte, within the pistil. Recent advances have clarified the molecular framework of gametophytic pollen tube guidance. Multiple species-specific attractant peptides are secreted from synergid cells, the proper development and function of which are regulated by female gametes. Multiple receptor-like kinases on the pollen tube tip are involved in sensing species-specific attractant peptides. In this Update article, recent progress in our understanding of the mechanism of gametophytic pollen tube guidance is reviewed, including attraction by synergid cells, control of pollen tube guidance by female gametes, and directional growth of the pollen tube by directional cue sensing. Future directions in the study of pollen tube guidance also are discussed. PMID:27920159

  16. Pollen tube branching in the ovary of five species of Oenothera

    Directory of Open Access Journals (Sweden)

    Renata Śnieżko

    2014-01-01

    Full Text Available Flowers of Oenothera hookeri Torr. et Gray, Oe. brevistylis and Oe. lamarkiana de Vries were pollinated after anthesis by insects. Oe. biennis L., Oe. suaveolens Desf and sulfurea were selfpollinated in the buds. Pollen morphology was slightly different: Oe. hookeri have regular, triporated pollen, often germinating through two pores; in Oe. suaveolens many pollen grains had callose patches on the intine; in Oe. brevistylis tetraporated pollen were more often than in other species; in Oe. lamarckiana many pollen grains were empty; in Oe. biennis and Oe. suaveolens pollen grain size and viability varied. The pollen tube growth and fertilization were similar in 5 species and can be considered as typical for Oenothera. In the ovary pollen tubes branched and changed their growth direction. Near micropyle they formed short branches to the inner integument. In the nucellus the pollen tube became swollen.

  17. Seed set variation in wildClarkiapopulations: teasing apart the effects of seasonal resource depletion, pollen quality, and pollen quantity.

    Science.gov (United States)

    Hove, Alisa A; Mazer, Susan J; Ivey, Christopher T

    2016-09-01

    In habitats where resource availability declines during the growing season , selection may favor early-flowering individuals. Under such ephemerally favorable conditions, late-blooming species (and individuals) may be particularly vulnerable to resource limitation of seed production. In California, a region prone to seasonal drought, members of the annual genus Clarkia are among the last to flower in the spring. We compared pollen limitation (PL) of seed set and outcrossing rates between early- and late-flowering individuals in two mixed-mating Clarkia taxa to detect whether flowering time is associated with changes in seed set due to resource depletion, PL, or increased selfing. In 2008-2010, we hand-pollinated one flower on a total of 1855 individual plants either Early (near the onset of flowering) or Late (near the end of flowering) in the flowering season and compared seed set to adjacent, open-pollinated flowers on the same stem. To assess the contribution of pollen quality to reproduction, we first (2008) used allozymes to estimate outcrossing rates of seeds produced by Early and Late open-pollinated flowers. Second (2009), we conducted an anther-removal experiment to estimate self-pollen deposition. Seed set in Clarkia unguiculata was not pollen-limited. Clarkia xantiana ssp . xantiana was pollen-limited in 2008 and 2010, but not 2009. PL did not differ between Early and Late treatments. In both taxa, seed set of Early flowers was greater than Late flowers, but not due to PL in the latter. Reproduction was generally pollinator-dependent. Most pollen deposition was xenogamous, and outcrossing rates were >0.7 - and similar between Early and Late periods. These results suggest that pollen receipt and pollen quality remain seasonally consistent. By contrast, the resources necessary to provision seeds decline, reducing the fitness benefits associated with resource allocation to ovules.

  18. Can spatial data substitute temporal data in phenological modelling? A survey using birch flowering.

    Science.gov (United States)

    Jochner, Susanne; Caffarra, Amelia; Menzel, Annette

    2013-12-01

    In addition to the evaluation of long-term series, the analysis of spatial gradients, such as urbanization gradients, may be helpful in assessing phenological responses to global warming. But are phenological responses of birch (Betula pendula Roth) assessed by temperature variations comparable over time and space and can spatially calibrated models predict long-term phenological data adequately? We calibrated and tested linear regression models and the process-based DORMPHOT model on phenological and temperature data sampled along an urbanization gradient in 2010 and 2011 in the German cities Munich and Ingolstadt (spatial data). Additionally, we analysed data from the German Meteorological Service for the period 1991-2010 (long-term data). The model comparison showed that the DORMPHOT model performed better than the linear model. Therefore, the importance of forcing and chilling sums as well as photoperiod, factors which were all considered in the DORMPHOT model, was evident. Models calibrated on spatial data produced good predictions of spatial data, but they were less adequate for predicting long-term data. Therefore, a time-for-space substitution might not always be appropriate. This finding was also confirmed by a comparison of temperature response rates. The rate of change in the spatial data (-4.4 days °C(-1)) did not match the changes observed in the long-term data (-1.9 days °C(-1)). Consequently, it is important not to generalize results derived from one specific study method, but their inherent methodological, spatial and temporal peculiarities have to be considered.

  19. Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.

    Science.gov (United States)

    de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

    2014-07-01

    Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. © 2013 John Wiley & Sons Ltd.

  20. Distribution and turnover of 137Cs in birch forest ecosystems: influence of precipitation chemistry

    International Nuclear Information System (INIS)

    Thørring, H.; Skuterud, L.; Steinnes, E.

    2012-01-01

    The aim of the present work was to study radioactive caesium in soil and plants from birch forests subject to different chemical climate. Four areas and three types of precipitation regimes were considered, representing a natural climatic range found in Norway: (A) acidic precipitation (southernmost part of the country); (B) precipitation rich in “sea salts”/marine cations (coastal areas); and (C) + (D) low concentrations of sea salts (inland areas). The results showed significant regional differences in plant uptake between the investigated areas. For instance the aggregated soil-to-plant transfer coefficients (Tag) were generally up to 7–8 times higher for the area receiving acid rain. Differences in caesium speciation partly explained the regional variability - e.g. the exchangeable fraction ranged from 1 to 40% (with the largest fraction of exchangeable caesium found in southernmost Norway). Transfer coefficients estimated on the basis of exchangeable fractions showed no significant differences between the areas of highest (A) and lowest (C) Tags. However, exchangeable fractions taken into consideration, the uptake of 137 Cs in plants in the acid rain-influenced area is still about twice that in the sea salt influenced area B. A significantly lower concentration of soluble base cations and a higher share of acid components in soils in area A is a likely explanation for this observation. - Highlights: ► Precipitation quality affects soil chemistry and plant uptake of Cs. ► Soil-to-plant transfer of Cs was highest in a coastal area receiving acid rain. ► Differences in Cs speciation partly explained regional transfer variability.

  1. Down-Regulating CsHT1, a Cucumber Pollen-Specific Hexose Transporter, Inhibits Pollen Germination, Tube Growth, and Seed Development.

    Science.gov (United States)

    Cheng, Jintao; Wang, Zhenyu; Yao, Fengzhen; Gao, Lihong; Ma, Si; Sui, Xiaolei; Zhang, Zhenxian

    2015-06-01

    Efficient sugar transport is needed to support the high metabolic activity of pollen tubes as they grow through the pistil. Failure of transport results in male sterility. Although sucrose transporters have been shown to play a role in pollen tube development, the role of hexoses and hexose transporters is not as well established. The pollen of some species can grow in vitro on hexose as well as on sucrose, but knockouts of individual hexose transporters have not been shown to impair fertilization, possibly due to transporter redundancy. Here, the functions of CsHT1, a hexose transporter from cucumber (Cucumis sativus), are studied using a combination of heterologous expression in yeast (Saccharomyces cerevisiae), histochemical and immunohistochemical localization, and reverse genetics. The results indicate that CsHT1 is a plasma membrane-localized hexose transporter with high affinity for glucose, exclusively transcribed in pollen development and expressed both at the levels of transcription and translation during pollen grain germination and pollen tube growth. Overexpression of CsHT1 in cucumber pollen results in a higher pollen germination ratio and longer pollen tube growth than wild-type pollen in glucose- or galactose-containing medium. By contrast, antisense suppression of CsHT1 leads to inhibition of pollen germination and pollen tube elongation in the same medium and results in a decrease of seed number per fruit and seed size when antisense transgenic pollen is used to fertilize wild-type or transgenic cucumber plants. The important role of CsHT1 in pollen germination, pollen tube growth, and seed development is discussed. © 2015 American Society of Plant Biologists. All Rights Reserved.

  2. Elevated air humidity affects hydraulic traits and tree size but not biomass allocation in young silver birches (Betula pendula

    Directory of Open Access Journals (Sweden)

    Arne eSellin

    2015-10-01

    Full Text Available As changes in air temperature, precipitation, and air humidity are expected in the coming decades, studies on the impact of these environmental shifts on plant growth and functioning are of major importance. Greatly understudied aspects of climate change include consequences of increasing air humidity on forest ecosystems, predicted for high latitudes. The main objective of this study was to find a link between hydraulic acclimation and shifts in trees’ resource allocation in silver birch (Betula pendula Roth in response to elevated air relative humidity (RH. A second question was whether the changes in hydraulic architecture depend on tree size. Two years of application of increased RH decreased the biomass accumulation in birch saplings, but the biomass partitioning among aboveground parts (leaves, branches, and stems remained unaffected. Increased stem Huber values (xylem cross-sectional area to leaf area ratio observed in trees under elevated RH did not entail changes in the ratio of non-photosynthetic to photosynthetic tissues. The reduction of stem-wood density is attributable to diminished mechanical load imposed on the stem, since humidified trees had relatively shorter crowns. Growing under higher RH caused hydraulic conductance of the root system (KR to increase, while KR (expressed per unit leaf area decreased and leaf hydraulic conductance increased with tree size. Saplings of silver birch acclimate to increasing air humidity by adjusting plant morphology (live crown length, slenderness, specific leaf area, and fine-root traits and wood density rather than biomass distribution among aboveground organs. The treatment had a significant effect on several hydraulic properties of the trees, while the shifts were largely associated with changes in tree size but not in biomass allocation.

  3. The Late Glacial and Holocene development of vegetation in the area of a fossil lake in the Skaliska Basin (north-eastern Poland inferred from pollen analysis and radiocarbon dating

    Directory of Open Access Journals (Sweden)

    Kołaczek Piotr

    2013-06-01

    Full Text Available The development of vegetation in the Skaliska Basin has been reconstructed on the basis of palynological analysis and radiocarbon dating (AMS technique of 6 sites from the late phase of the Bolling- Allerod interstadial complex to modern times. Although the area covers 90 km2, the mosaic character of habitats led to the development of different patterns of vegetation changes during the Late Glacial and Holocene. Only one site located in the eastern part of the Skaliska Basin reflected the ‘pine phase’ of Allerod, and this is the oldest data on vegetation in the Skaliska Basin. Interesting discrepancies were recorded during the Younger Dryas when patches of shrublands with Juniperus were distinct around some of the sites, while steppe with Artemisia was common in others. The beginning of the Holocene brought an expansion of birch-pine forest, but around 9600 cal. BC a cold oscillation took place which was reflected in an increase in birch in the woodlands in the western and eastern part of the Skaliska Basin. In the Preboreal chronozone elm (Ulmus also expanded in the area but its appearance was non-synchronous. The vegetation of the Boreal chronozone was similar in the whole area and the most characteristic feature was the rapid expansion of hazel (Corylus avellana which displaced Betula from the most of its sites. At that time a distinct redeposition of pollen material in the Parchatka river valley was detected which was probably the effect of an increase in fluvial activity of the river (humid oscillation. The following stage of vegetation development was climax woodlands with Tilia cordata, Ulmus, Quercus, Corylus avellana, and Alnus in damp places. At the beginning of the Subboreal chronozone the expansion of Quercus took place, which was subsequently replaced by Picea abies and partly Carpinus betulus. The pattern of Picea abies expansion distinctly presents two maxima which is characteristic of many sites in the north-eastern Poland

  4. Calcium in pollen-pistil interaction in `Petunia hybrida Hor`. Pt. 1. Localization of Ca{sup 2+} ions in mature pollen grain using pyroantimonate and autoradiographic methods

    Energy Technology Data Exchange (ETDEWEB)

    Bednarska, E.; Butowt, R. [Uniwersytet Mikolaja Kopernika, Torun (Poland)

    1994-12-31

    The localization of Ca{sup 2+} in the mature pollen grain and the flow of these ions the somatic tissues of the anther to the pollen grains has been studied using pyroantimonate and autoradiographic methods. In the pollen grain, Ca{sup 2+} ions have been localized in the sporoderm in the cytoplasmic vesicles of probably dictyosomal origin. Calcium ions were transported into the sporoderm together with the compounds of degenerating tapetum. The material of degenerating tapetum forms pollen coat surrounding the mature pollen grains. (author). 18 refs, 9 figs.

  5. Current glimpse of airborne allergenic pollen in Indian subcontinent

    Directory of Open Access Journals (Sweden)

    Kavita Ghosal

    2015-12-01

    Full Text Available Respiratory allergic diseases such as bronchial asthma, rhinitis, urticaria, atopic dermatitis have been steadily increasing all over the world, including India. Owing to its alarming trend, several aerobiological surveys have been undertaken in different parts of India to delineate the variety of pollen and spore load. In this review, we have reported the current state of aerobiological knowladge in India with particular reference to allergenic airborn pollen occurence in 2001–2015. Pollen have been found to contribute a significant proportion in the air and caused allergy symptoms in the local inhabitants. Aerobiological records, a questionnaire survey and hospitalization records have been employed for the analysis. Holoptelea integrifolia, Amaranthus spinosus in northern region, Sorghum vulgare, Pennisetum, Gynandropsis gynandra, Parthenium hysterophorus, Dolichandrone platycalyx in southern regions, and Parthenium hysterophorus from the western region; Cynodon dactylon, Cenchrus ciliaris in the central area; Acacia auriculiformis, Cleome gynandra, Catharanthus roseus, Phoenix sylvestris, Areca catechu, and Lantana camara in the eastern regions as potential aeroallergens in India. The statistical approach confirmed the correlation between hospitalization rate associated with allergy-related health troubles and the prevalent allergenic pollen in the air. The Poaceae group has been found to be dominant throughout India. Immuno-biochemical studies identified various protein with allergenic potential found in the pollen recorded. Epitope identification and homology of the major allergenic protein Cat r1 of Catharanthus sp and Par j 1 of Parietaria judaica have been found. Identification of allergenic pollen grains and the modern approach concerning cross-reactivity and epitope revelation of dominant airborne pollen have important clinical implications for the prevention, diagnosis and treatments of allergic diseases in India.

  6. Nuclear membrane localization during pollen development and apex-focused polarity establishment of SYP124/125 during pollen germination in Arabidopsis thaliana.

    Science.gov (United States)

    Ichikawa, Mie; Iwano, Megumi; Sato, Masa H

    2015-12-01

    Establishment of apex-polarity. Elongation of the pollen tube is a highly coordinated process involving polarized secretion of cell wall and membrane materials to the apical region. We investigated changes in the localization of soluble NSF attachment proteins (SNAREs) in developing pollen grains and the pollen tube for transgenic Arabidopsis expressing pollen-specific plasma-membrane Qa-SNAREs (SYP124, 125 and 131) fused with the green fluorescent protein (GFP). The expression of SYP124 and SYP125 was firstly detected in the microspore nuclear membrane during pollen mitosis II. Although SYP124, 125 and 131 accumulated throughout the cytosol in the mature pollen grain, GFP-SYP124 and GFP-SYP125 were highly concentrated in the apical or subapical regions of the elongating pollen tube with slightly different localization patterns, whereas GFP-SYP131 was uniformly localized to the plasma membrane of the pollen tube. The apex-focused polarity of GFP-SYP125 was established coincident with formation of a Ca(2+) gradient before pollen germination. These results suggest that SNAREs function differentially in the same cells and that at least two distinct membrane transport pathways are involved in the pollen development and the pollen tube germination and elongation.

  7. Use of MODIS Satellite Data to Evaluate Juniperus spp. Pollen Phenology to Support a Pollen Dispersal Model, PREAM, to Support Public Health Allergy Alerts

    Science.gov (United States)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A.; Nickovic, S.; Prasad, A.; Pejanovic, G. A.; Vukovic, A.; VandeWater, P. K.; Budge, A. M.; hide

    2013-01-01

    Pollen can be transported great distances. Van de Water et. al., 2003 reported Juniperus spp. pollen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. The DREAM (Dust REgional Atmospheric Model) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and concentrations of dust. We are modifying the DREAM model to incorporate pollen transport. Pollen emission is based on MODIS-derived phenology of Juniperus spp. communities. Ground-based observational records of pollen release timing and quantities will be used as model verification. This information will be used to support the Centers for Disease Control and Prevention s National Environmental Public Health Tracking Program and the State of New Mexico environmental public health decision support for asthma and allergies alerts

  8. Use of MODIS Satellite Data to Evaluate Juniperus spp. Pollen Phenology to Support a Pollen Dispersal Model, PREAM, to Support Public Health Allergy Alerts

    Science.gov (United States)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A. R.; Nickovic, S.; Prasad, A. K.; Pejanovic, G.; Vukovic, A.; Van De Water, P. K.; Budge, A.; Hudspeth, W. B.; Krapfl, H.; Toth, B.; Zelicoff, A.; Myers, O.; Bunderson, L.; Ponce-Campos, G.; Menache, M.; Crimmins, T. M.; Vujadinovic, M.

    2012-12-01

    Pollen can be transported great distances. Van de Water et. al., 2003 reported Juniperus spp. pollen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. The DREAM (Dust REgional Atmospheric Model, Nickovic et al. 2001) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and concentrations of dust. We are modifying the DREAM model to incorporate pollen transport. Pollen emission is based on MODIS-derived phenology of Juniperus spp. communities. Ground-based observational records of pollen release timing and quantities will be used as model verification. This information will be used to support the Centers for Disease Control and Prevention's National Environmental Public Health Tracking Program and the State of New Mexico environmental public health decision support for asthma and allergies alerts.

  9. Molecular evidence that most RNAs required for germination and pollen tube growth are stored in the mature pollen grain in petunia.

    Science.gov (United States)

    Ishimizu, Takeshi; Kodama, Hiroaki; Ando, Toshio; Watanabe, Masao

    2010-01-01

    After landing on the stigma, the pollen grain germinates and elongates a tube to deliver its generative nuclei to the egg cell of the ovule. The molecular mechanisms involved in the drastic morphological changes in the pollen grain during this fertilization process remain largely unknown. In this study, the expression of 732 randomly selected genes in petunia pollen and pollen tubes was analyzed by microarray and quantitative PCR analyses. We found no evidence for up-regulation of any of these genes in the pollen tube. Our findings provide support at the gene level for the longstanding hypothesis that pollen germination and tube growth are not dependent on new RNA synthesis and that the large number of RNAs required for germination and tube growth are stored in mature pollen grains.

  10. The effect of cisplatin administration on certain trace elements homeostasis in rats and the protective effect of silver birch (Betula pendula) sap.

    Science.gov (United States)

    Muselin, Florin; Dumitrescu, Eugenia; Berbecea, Adina; Doma, Alexandru Octavian; Brezovan, Diana; Savici, Jelena; Trif, Alexandra; Cristina, Romeo Teodor

    2018-02-07

    A clinically active structure with known antitumor activities is cisplatin (CDDP), but this it comes with toxicity characteristics which can be faded by the beneficial effects of Silver birch (Betula pendula) sap. We aimed to assess the cisplatin activity on: Mn, Mg, Cu, Fe and Zn homeostasis in rats and to observe the effect of birch sap. Healthy Wistar rats (n = 10/group) were divided in four groups: Control: receiving 1 mL saline I.P. way + water; E1: cisplatin 20 mg kgbw -1 , I.P.; E2: cisplatin 20 mg kgbw -1 , I.P. + birch sap and Control sap group: 1 mL saline I.P. + birch sap. Blood was collected: at the trial's start and after 48 h, and blood and organs (liver, kidney and spleen) for the cytoarchitecture investigation and readings were sampled after seven days. Samples were processed in nitric acid by microwave digestion and readings were completed by flame atomic absorption spectroscopy, the outcomes being statistically analyzed by ANOVA. Cisplatin produced a significant imbalance in the trace elements homeostasis, the birch sap administration recovering them usual homeostasis status. Comparatively with the Control, rats exposed to cisplatin presented a not significant (p > 0.05) decrease of Zn (-26.74%) and Mg (-10.25%), a significant (p  0.05) increase of Mn (+28.16%). Birch sap administration after Cisplatin was followed by restoration or nevertheless significant increase (p sap against diverse cisplatin deleterious side-effects. Copyright © 2018 Elsevier GmbH. All rights reserved.

  11. Pollen structure and development in Nymphaeales: insights into character evolution in an ancient angiosperm lineage.

    Science.gov (United States)

    Taylor, Mackenzie L; Cooper, Ranessa L; Schneider, Edward L; Osborn, Jeffrey M

    2015-10-01

    A knowledge of pollen characters in early-diverging angiosperm lineages is essential for understanding pollen evolution and the role of pollen in angiosperm diversification. In this paper, we report and synthesize data on mature pollen and pollen ontogeny from all genera of Nymphaeales within a comparative, phylogenetic context and consider pollen evolution in this early-diverging angiosperm lineage. We describe mature pollen characters for Euryale, Barclaya, and Nymphaea ondinea, taxa for which little to no structural data exist. We studied mature pollen for all nymphaealean genera using light, scanning electron, and transmission electron microscopy. We reviewed published reports of nymphaealean pollen to provide a comprehensive discussion of pollen characters in water lilies. Nymphaeales exhibit diversity in key pollen characters, including dispersal unit size, ornamentation, aperture morphology, and tapetum type. All Nymphaeales pollen are tectate-columellate, exhibiting one of two distinct patterns of infratectal ultrastructure-a thick infratectal space with robust columellae or a thin infratectal space with thin columellae. All genera have pollen with a lamellate endexine that becomes compressed in the proximal, but not distal wall. This endexine ultrastructure supports the operculate hypothesis for aperture origin. Nymphaeaceae pollen exhibit a membranous granular layer, which is a synapomorphy of the family. Variation in pollen characters indicates that significant potential for lability in pollen development was present in Nymphaeales at the time of its divergence from the rest of angiosperms. Structural and ontogenetic data are essential for interpreting pollen characters, such as infratectum and endexine ultrastructure in Nymphaeales. © 2015 Botanical Society of America.

  12. Long-term storage method for soft X-ray irradiated 'Hyuganatsu' pollen

    International Nuclear Information System (INIS)

    Yano, S.; Tanaka, M.; Ohara, N.

    2008-01-01

    The long-term storage conditions for 'Hyuganatsu ' pollen that had been irradiated with soft X-rays was examined. This study, was aimed at production of 'Tosa-buntan' without formation of nuclear fruit. 1. We evaluated the germination rate of pollen that had been irradiated with soft X-ray (500 or 1,000 Gy) and stored at 3 deg C, -20 deg C, and -40 deg C. The germination rate was the same as that of unirradiated pollen, even after storage for 1 year. Soft X-ray irradiation did not influence the storage attributes of pollen. 2. In unirradiated pollen and pollen that had been irradiated with soft X-ray (500 or 1,000 Gy), temperature conditions necessary for storing from 3 months to 1 year were -20 deg C or less, and pollen stored at -40 deg C had a higher germination rate after 1 year. 3. The germination rate was 1% or less in 4 months if silica gel was sealed into a gas barrier bag with 1,000 Gy-irradiated pollen at a rate of 10:1 (w/w). The ability to germinate was completely lost after 1 year in these conditions. 4. We evaluated the effect of sealing methods on 1,000 Gy-irradiated pollen stored at -20 deg C. There was no difference in germination rates among pollen stored in gas-barrier bags, vacuum-packaged pollen, and pollen stored with nitrogen in gas-barrier bags. Moreover, the germination rate of 750 Gy-irradiated pollen stored at -20 deg C decreased from 3 months onwards when pollen was stored with a free-oxygen absorber (Ageless ZP). 5. Pollen that was treated with acetone before or after soft X-ray irradiation (750 Gy) withstood long-term storage of 1 year. Long-term storage was possible if pollen was stored at -20 deg C, as is the case for rough pollen

  13. Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

    Science.gov (United States)

    Aboulaich, Nadia; Achmakh, Lamiaa; Bouziane, Hassan; Trigo, M. Mar; Recio, Marta; Kadiri, Mohamed; Cabezudo, Baltasar; Riadi, Hassane; Kazzaz, Mohamed

    2013-03-01

    Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008-2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114-173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m3. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2-78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33-42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.

  14. Spatial variation of modern pollen in Oregon and southern Washington, USA.

    Science.gov (United States)

    Minckley; Whitlock

    2000-10-01

    Surface sediments from 95 lakes provide information on the spatial variation of modern pollen spectra in Oregon and southern Washington. Percentages for 13 pollen types were compared within and between vegetation zones to characterize regional patterns of pollen spectra. The percentage data were also compared with climate variables to determine relationships between pollen percentages and regional climate gradients. The composition of modern pollen spectra corresponds well with the distribution of the pollen producers. Most pollen assemblages were generally dominated by Pinus, but those west of the Cascade Range were dominated by Alnus. Low percentages of Pseudotsuga/Larix, Tsuga mertensiana, Abies, and Picea pollen coincided with local occurrence of the trees. The distributions of the pollen data were arranged along gradients of temperature and effective moisture. West of the Cascade Range, Alnus, Tsuga heterophylla, Pseudotsuga/Larix, and Cupressaceae pollen were abundant and correlate well with moderate temperature and high effective moisture. In the shrub-steppe and woodlands east of the Cascade Range, where effective moisture is low, Artemisia, Cupressaceae, and Pinus pollen were dominant. At high elevations, Pinus, T. mertensiana, Abies, and Picea were common pollen types in areas with short growing seasons and high effective moisture. Pollen percentages collected from lake surface sediments, moss polsters, and soils were compared within a number of vegetation types to assess their similarity. The three types of sample yielded similar results for forested areas, but lake sediment samples from upper- and lower-treeline sites captured a more regional picture of the vegetation.

  15. Flowering phenology and potential pollen emission of threeArtemisiaspecies in relation to airborne pollen data in Poznań (Western Poland).

    Science.gov (United States)

    Bogawski, Paweł; Grewling, Łukasz; Frątczak, Agata

    Artemisia pollen is an important allergen in Europe. In Poznań (Western Poland), three Artemisia species, A. vulgaris , A. campestris and A. absinthium , are widely distributed. However, the contributions of these species to the total airborne pollen are unknown. The aim of the study was to determine the flowering phenology and pollen production of the three abovementioned species and to construct a model of potential Artemisia pollen emission in the study area. Phenological observations were conducted in 2012 at six sites in Poznań using a BBCH phenological scale. Pollen production was estimated by counting the pollen grains per flower and recalculating the totals per inflorescence, plant and population in the study area. Airborne pollen concentrations were obtained using a Hirst-type volumetric trap located in the study area. Artemisia vulgaris began to flower the earliest, followed by A. absinthium and then A. campestris . The flowering of A. vulgaris corresponded to the first peak in the airborne pollen level, and the flowering of A. campestris coincided with the second pollen peak. The highest amounts of pollen per single plant were produced by A. vulgaris and A. absinthium . A. campestris produced considerably less pollen, however, due to its common occurrence, it contributed markedly (30 %) to the summation of total of recorded pollen. A. vulgaris is the most important pollen source in Poznań, but the roles of two other Artemisia species cannot be ignored. In particular, A. campestris should be considered as an important pollen contributor and likely might be one of the main causes of allergic reactions during late summer.

  16. An experimental test of whether habitat corridors affect pollen transfer.

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Patricia A.; Levey, Douglas J.

    2005-02-01

    Abstract. Negative effects of habitat fragmentation are thought to be diminished when habitat patches are joined by a corridor. A key assumption is that corridors facilitate exchange rates of organisms between otherwise isolated patches. If the organisms are pollinators, corridors may be important for maintaining genetically viable populations of the plants that they pollinate. We tested the hypothesis that corridors increase the movement of insect pollinators into patches of habitat and thereby increase pollen transfer for two species of plants, one pollinated by butterflies (Lantana camara) and the other by bees and wasps (Rudbeckia hirta). We worked in an experimental landscape consisting of 40 greater than or equal to 1-ha patches of early-successional habitat in a matrix of forest. Within each of eight experimental units, two patches were connected by a corridor (150 X 25 m), and three were not. Patch shape varied to control for the area added by the presence of a corridor. Differences in patch shape also allowed us to test alternative hypotheses of how corridors might function. The Traditional Corridor Hypothesis posits that corridors increase immigration and emigration by functioning as movement conduits between patches. The Drift Fence Hypothesis posits that corridors function by ‘‘capturing’’ organisms dispersing through the matrix, redirecting them into associated habitat patches. Using fluorescent powder to track pollen, we found that pollen transfer by butterflies between patches connected by a corridor was significantly higher than between unconnected patches (all values mean plus or minus 1 SE: 59% plus or minus 9.2% vs. 25% plus or minus 5.2% of flowers receiving pollen). Likewise, pollen transfer by bees and wasps was significantly higher between connected patches than between unconnected patches (30% plus or minus 4.2% vs. 14.5% plus or minus 2.2%). These results support the Traditional Corridor Hypothesis. There was little support, however

  17. Climate Change and Future Pollen Allergy in Europe.

    Science.gov (United States)

    Lake, Iain R; Jones, Natalia R; Agnew, Maureen; Goodess, Clare M; Giorgi, Filippo; Hamaoui-Laguel, Lynda; Semenov, Mikhail A; Solomon, Fabien; Storkey, Jonathan; Vautard, Robert; Epstein, Michelle M

    2017-03-01

    Globally, pollen allergy is a major public health problem, but a fundamental unknown is the likely impact of climate change. To our knowledge, this is the first study to quantify the consequences of climate change upon pollen allergy in humans. We produced quantitative estimates of the potential impact of climate change upon pollen allergy in humans, focusing upon common ragweed ( Ambrosia artemisiifolia ) in Europe. A process-based model estimated the change in ragweed's range under climate change. A second model simulated current and future ragweed pollen levels. These findings were translated into health burdens using a dose-response curve generated from a systematic review and from current and future population data. Models considered two different suites of regional climate/pollen models, two greenhouse gas emissions scenarios [Representative Concentration Pathways (RCPs) 4.5 and 8.5], and three different plant invasion scenarios. Our primary estimates indicated that sensitization to ragweed will more than double in Europe, from 33 to 77 million people, by 2041-2060. According to our projections, sensitization will increase in countries with an existing ragweed problem (e.g., Hungary, the Balkans), but the greatest proportional increases will occur where sensitization is uncommon (e.g., Germany, Poland, France). Higher pollen concentrations and a longer pollen season may also increase the severity of symptoms. Our model projections were driven predominantly by changes in climate (66%) but were also influenced by current trends in the spread of this invasive plant species. Assumptions about the rate at which ragweed spreads throughout Europe had a large influence upon the results. Our quantitative estimates indicate that ragweed pollen allergy will become a common health problem across Europe, expanding into areas where it is currently uncommon. Control of ragweed spread may be an important adaptation strategy in response to climate change. Citation: Lake IR

  18. Enhanced airborne radioactivity during a pine pollen release episode

    Energy Technology Data Exchange (ETDEWEB)

    Tschiersch, J.; Frank, G.; Roth, P.; Wagenpfeil, F. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany). Inst. fuer Strahlenschutz; Watterson, J. [AEA Technology, Culham (United Kingdom)

    1999-07-01

    A single episode of pine pollen release in the highly contaminated area of Novozybkov, Russian Federation, which led to enhanced atmospheric concentrations of {sup 137}Cs is discussed. The pollen grains were sampled by a rotating arm impactor and analysed by gamma-spectrometry for {sup 137}Cs activity and by image analysis for their size. In the vicinity of a forest, a maximum concentration of 4.5{+-}0.4 mBq m{sup -3} was measured, and a mean activity per pollen grain of 260{+-}80 nBq was determined. The emission rate of the Novozybkov mixed pine forest was estimated to be approximately 400 Bq m{sup -2} per year. Because of the large size of pine pollen grains (about 50 {mu}m) and the short emission period of 5-8 days per year, the estimated potential annual inhalation doses are very low. Biological emissions including pollen release may be a source of increased airborne radionuclide concentrations at larger distance from the source areas as well. (orig.)

  19. Personalized symptoms forecasting for pollen-induced allergic rhinitis sufferers

    Science.gov (United States)

    Voukantsis, D.; Berger, U.; Tzima, F.; Karatzas, K.; Jaeger, S.; Bergmann, K. C.

    2015-07-01

    Hay fever is a pollen-induced allergic reaction that strongly affects the overall quality of life of many individuals. The disorder may vary in severity and symptoms depending on patient-specific factors such as genetic disposition, individual threshold of pollen concentration levels, medication, former immunotherapy, and others. Thus, information services that improve the quality of life of hay fever sufferers must address the needs of each individual separately. In this paper, we demonstrate the development of information services that offer personalized pollen-induced symptoms forecasts. The backbone of these services consists of data of allergic symptoms reported by the users of the Personal Hay Fever Diary system and pollen concentration levels (European Aeroallergen Network) in several sampling sites. Data were analyzed using computational intelligence methods, resulting in highly customizable forecasting models that offer personalized warnings to users of the Patient Hay Fever Diary system. The overall system performance for the pilot area (Vienna and Lower Austria) reached a correlation coefficient of r = 0.71 ± 0.17 (average ± standard deviation) in a sample of 219 users with major contribution to the Pollen Hay Fever Diary system and an overall performance of r = 0.66 ± 0.18 in a second sample of 393 users, with minor contribution to the system. These findings provide an example of combining data from different sources using advanced data engineering in order to develop innovative e-health services with the capacity to provide more direct and personalized information to allergic rhinitis sufferers.

  20. [Description and value of the Microvision system for pollen analysis].

    Science.gov (United States)

    Thibaudon, M; Lachasse, C

    2004-09-01

    Currently, two techniques of analysis are classically used by the aerobiological networks: the technique of the 12 vertical lines allow to follow the evolution by bi-hourly periods of pollination, but the segmentation of the sample doesn't allow to visualise pollen clouds of short duration; the technique of 2 or 3 horizontal lines allow to follow the daily evolution, but only the daily totals are recorded. The MICROVISION system adapted by the RNSA to the pollen analysis allow to keep the horizontal method, which is faster and continue, and to record automatically in the database the hourly or bi-hourly data. So each pollen is recorded by its coordinates with a precision of 1 micron (1.8 seconds). First, we realised a cartography of the impaction of the pollen grains on the strip, in order to locate the more representative horizontal lines. Secondly, the coupling of the microscope with the Microvision system and the software of data acquiring elaborated by the RNSA allow to propose a more reliable and faster procedure for pollen analysis.