WorldWideScience

Sample records for acetolysis

  1. 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.

  2. High secondary [alpha]-deuterium kinetic isotope effect in the acetolysis and formolysis of dideuterioferrocenylmethyl benzoate

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, S. (Research Center of the Croatian Academy of Sciences and Arts, Zagreb (Croatia)); Kukric, Z.; Sutic, D. (Sarajevo Univ. (Yugoslavia). Faculty of Natural Sciences and Mathematics); Saunders, W.H. Jr. (Rochester Univ., NY (United States). Dept. of Chemistry)

    1992-02-01

    Acetolysis and formolysis of dideuterioferrocenylmethyl benzoate exhibit large secondary deuterium kinetic isotope effects and an abnormal temperature dependence. In the presence of LiClO[sub 4], which prevents the reversion from solvent-separated to contact ion-pairs, K[sub H]/K[sub D] at 25 [sup o]C amount to 1.53 [+-] 0.02 (acetolysis) and 1.48 [+-] 0.03 (formolysis). In the presence of LiClO[sub 4] the ratios of Arrhenius pre-exponential factors, A[sub H]/A[sub D], are significantly less than unity and amount to 0.49 [+-] 0.01 (acetolysis) and 0.38 [+-] 0.04 (formolysis). In the absence of LiClO[sub 4] the A[sub H]/A[sub D] ratios are much smaller (0.02 both in acetolysis and formolysis). We suggest that these surprisingly low values result from a change in rate-determining step over the temperature range, from formation of the solvent-separated ion-pair at low temperatures to reaction of the dissociated carbocation with solvent at the highest temperatures. Whether tunnelling plays any role in these solvolyses is discussed. (Author).

  3. Size modification of recent pollen grains under different treatments

    NARCIS (Netherlands)

    Reitsma, Tj.

    1969-01-01

    The effect of various chemicals on the size of recent pollen grains of Corylus avellana L. and Quercus robur L. was studied. The size of acetolysed grains was affected by the treatment prior to acetolysis and moreover by the duration of acetolysis. Preparation methods, which produce comparable sizes

  4. [Preparative approach to mannobiose and laminaribiose (author's transl)].

    Science.gov (United States)

    Thiem, J; Sievers, A; Karl, H

    1977-01-11

    For synthetic purposes mannobiose is isolated from the polysaccharide mannan of ivory nut flower. The chain length of mannan A is determined to approximately 15 mannose units on average with a definite distribution from 5 to 25 mannose units. Acetolysis is optimized and yields 41% mannobiose. The separation on Sephadex G-15 yields pure mannobiose, and in addition its higher homologues in gram amounts. Detection of the eluates is performed using a differential refractometer. Correspondingly laminaribiose can be obtained from the polysaccharides laminaran (brown algae Laminaria hyperborea) and pachyman (fungus Poria cocos Wolf, Bukuryo) by selectively optimized acetolysis in 30% yield. Depending on the starting material separations are favourably performed on silica gel or on Sephadex G-15. Laminaribiose and its higher homologues are obtained in gram amounts.

  5. The impact of oxidation on spore and pollen chemistry: an experimental study

    Science.gov (United States)

    Jardine, Phillip; Fraser, Wesley; Lomax, Barry; Gosling, William

    2016-04-01

    Sporomorphs (pollen and spores) form a major component of the land plant fossil record. Sporomorphs have an outer wall composed of sporopollenin, a highly durable biopolymer, the chemistry of which contains both a signature of ambient ultraviolet-B flux and taxonomic information. Despite the high preservation potential of sporopollenin in the geological record, it is currently unknown how sensitive its chemical signature is to standard palynological processing techniques. Oxidation in particular is known to cause physical degradation to sporomorphs, and it is expected that this should have a concordant impact on sporopollenin chemistry. Here, we test this by experimentally oxidizing Lycopodium (clubmoss) spores using two common oxidation techniques: acetolysis and nitric acid. We also carry out acetolysis on eight angiosperm (flowering plant) taxa to test the generality of our results. Using Fourier Transform infrared (FTIR) spectroscopy, we find that acetolysis removes labile, non-fossilizable components of sporomorphs, but has a limited impact upon the chemistry of sporopollenin under normal processing durations. Nitric acid is more aggressive and does break down sporopollenin and reorganize its chemical structure, but when limited to short treatments (i.e. ≤10 min) at room temperature sporomorphs still contain most of the original chemical signal. These findings suggest that when used carefully oxidation does not adversely affect sporopollenin chemistry, and that palaeoclimatic and taxonomic signatures contained within the sporomorph wall are recoverable from standard palynological preparations.

  6. 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.

  7. Le δ13C des grains de pollen : intérêt pour l'étude des paléovégétationsCarbon isotopic ratios of pollen: interest for palaeovegetations reconstructions

    Science.gov (United States)

    Descolas-Gros, Chantal; Calleja, Michel; Cour, Pierre; Richard, Paul; Perruchietti, Christiane; Jame, Patrick

    2001-06-01

    δ13C values of pollen grains belonging to different plant species (trees, herbaceous no poaceae, poaceae) were measured. Most of these temperate species are C3 plants with δ13C values between -28.6 ‰ and -21.7 ‰, the C4 plants have more positive values between -15.9 ‰ and -10 ‰. These results corroborate the interest of such measurements to differentiate C4 poaceae from C3 ones. Inside the same genus or the same species data variability is studied. Chemical treatment (acetolysis) of pollen grains induces a lowering of the values. These preliminary results are intended to help calibrate the pollen grains δ13C of modern plants in order to use δ13C of fossil pollen grains to reconstruct palaeovegetation variability responses to climatic factors.

  8. 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.

  9. Palynomorphs in Holocene sediments from a paleolagoon in the coastal plain of extreme southern Brazil

    Directory of Open Access Journals (Sweden)

    Ebráilon Masetto

    2014-06-01

    Full Text Available This paper presents the results of a qualitative palynological analysis of a 140 cm-thick section of Holocene sediments from a paleolagoon, representing the last 2600 years, taken from an outcrop at Hermenegildo Beach (33º42'S; 53º18'W, located in the municipality of Santa Vitória do Palmar, in the state of Rio Grande do Sul, Brazil. Samples were treated with hydrochloric acid, hydrofluoric acid and potassium hydroxide, after which they were subjected to acetolysis and mounted on glycerin-coated slides for light microscopy analysis. Among the 48 palynomorphs identified were 25 fungi, eight algae, three bryophytes, and 12 pteridophytes. Brief descriptions and illustrations of each palynomorph are presented, together with ecological data from the organism of origin when possible. Our findings will serve as reference material for paleoenvironmental studies in the coastal plain of southern Brazil.

  10. Pollen storages in nests of bees of the genera Partamona, Scaura and Trigona (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    André Rodrigo Rech

    2011-09-01

    Full Text Available Bees and angiosperms established a mutualistic relationship along the evolutionary time. The aim of this study is to contribute for the understanding of this relation analyzing pollen stored by stingless bees colonies distributed along the Rio Negro. Fourteen species of Meliponini from the genera Partamona, Scaura, and Trigona were studied with regard to the content of pollen pots. The pollen material was removed from the pollen pots, homogenized, and prepared according to the usual acetolysis technique. The overlap of the trophic niche and the grouping of species by similarity of niches was calculated. The identification revealed 78 pollen types belonging to 36 families, being 37 types attractive and 16 considered as promoters of a temporary specialization event. With the results, it was possible to indicate a list of important plants for meliponiculture in the Amazon.

  11. Characterization of oligosaccharides from an antigenic mannan of Saccharomyces cerevisiae.

    Science.gov (United States)

    Young, M; Davies, M J; Bailey, D; Gradwell, M J; Smestad-Paulsen, B; Wold, J K; Barnes, R M; Hounsell, E F

    1998-08-01

    Mannans of the yeast Saccharomyces cerevisiae have been implicated as containing the allergens to which bakers and brewers are sensitive and also the antigen recognized by patients with Crohn's disease. A fraction of S. cerevisiae mannan, Sc500, having high affinity for antibodies in Crohn's patients has been characterized by NMR spectroscopy followed by fragmentation using alkaline elimination, partial acid hydrolysis and acetolysis. The released oligosaccharides were separated by gel filtration on a Biogel P4 column and analyzed by fluorescence labeling, HPLC and methylation analysis. The relationship between structure and antigen activity was measured by competitive ELISA. The antigenic activity of the original high molecular weight mannan could be ascribed to terminal Manalpha1-->3Manalpha1-->2 sequences which are rarely found in human glycoproteins but were over-represented in Sc500 compared to other yeast mannans.

  12. Identification of Sporopollenin as the Outer Layer of Cell Wall in Microalga Chlorella protothecoides

    Science.gov (United States)

    He, Xi; Dai, Junbiao; Wu, Qingyu

    2016-01-01

    Chlorella protothecoides has been put forth as a promising candidate for commercial biodiesel production. However, the cost of biodiesel remains much higher than diesel from fossil fuel sources, partially due to the high costs of oil extraction from algae. Here, we identified the presence of a sporopollenin layer outside the polysaccharide cell wall; this was evaluated using transmission electron microscopy, 2-aminoethanol treatment, acetolysis, and Fourier Transform Infrared Spectroscopy. We also performed bioinformatics analysis of the genes of the C. protothecoides genome that are likely involved in sporopollenin synthesis, secretion, and translocation, and evaluated the expression of these genes via real-time PCR. We also found that that removal of this sporopollenin layer greatly improved the efficiency of oil extraction. PMID:27446068

  13. Identification of Sporopollenin as the Outer Layer of Cell Wall in Microalga Chlorella protothecoides.

    Science.gov (United States)

    He, Xi; Dai, Junbiao; Wu, Qingyu

    2016-01-01

    Chlorella protothecoides has been put forth as a promising candidate for commercial biodiesel production. However, the cost of biodiesel remains much higher than diesel from fossil fuel sources, partially due to the high costs of oil extraction from algae. Here, we identified the presence of a sporopollenin layer outside the polysaccharide cell wall; this was evaluated using transmission electron microscopy, 2-aminoethanol treatment, acetolysis, and Fourier Transform Infrared Spectroscopy. We also performed bioinformatics analysis of the genes of the C. protothecoides genome that are likely involved in sporopollenin synthesis, secretion, and translocation, and evaluated the expression of these genes via real-time PCR. We also found that that removal of this sporopollenin layer greatly improved the efficiency of oil extraction. PMID:27446068

  14. PERKEMBANGAN MIKROGAMETOFIT DAN UJI VIABILITAS SERBUK SARI KELAPA (Cocos nucifera L. “Ancak”

    Directory of Open Access Journals (Sweden)

    Ni Luh Gede Cerli Tonika Sari

    2013-12-01

    Full Text Available The research observed the type of pollen shape, development of microgametophyte, andpollen viability of Cocos nucifera L. “Ancak”, that is the pollen structure Cocos nucifera L. usedpreparation with acetolysis method. Development of microgametophyte, and pollen viabilitywith germinated pollen in vitro used 0,8% of agar media in sugar solution 0%, 50%, and 70%.The result showed that the type of pollen shape Cocos nucifera L. “Ancak”: circular, sulkus,media, Subferoidal, P/E: (1.12-1.18. Development of microgametophyte Cocos nucifera L.“Ancak” the flowers are ripe generally at the level of uninucleate (> 60% and binukleat (<40%.Male gametes (trinukleat started on day 2,4. percentage of pollen viability in vitro low average(< 2.5%.Keywords: Pollen structure, microgametophyte, viability test, in vitro

  15. Plants used by Megachile (Moureapis) sp. (Hymenoptera: Megachilidae) in the provisioning of their nests.

    Science.gov (United States)

    Buschini, M L T; Rigon, J; Cordeiro, J

    2009-11-01

    This study was carried out in the Parque Municipal das Araucárias, located in the municipality of Guarapuava (PR) from May (06) to April (07). Its aim was to investigate which plants are used by Megachile (Moureapis) sp in provisioning of larvae, and to verify if this bee is oligolectic or polilectic. The collection of the plants was carried out during the bees activity period and in an area covering a 500 m radius from where the nests had been built. A sample of pollens from founded nests and from flowers was used to make permanent slides using the acetolysis method and with the aid of a light microscope, all pollen grains were examined in order to identify the plants used by this bee. A total of 80 pollen grain slides, from 16 nests were analysed. Although 99 plants were collected close to the bee's nesting site, in nest slides, the pollen of Ludwigia peruviana (36%) and Ludwigia sericea (63.6%) (Onagraceae) accounted for 99.6% of the total amount of pollen collected. With these results we are able to conclude that Megachile (Moureapis) sp is an oligolectic species and that these plants species are their important pollen source. PMID:19967192

  16. 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.

  17. Ostracod fauna across the Permian-Triassic boundary at Chongyang, Hubei Province, and its implication for the process of the mass extinction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Thirty species of 10 ostracod genera were identified from 440 fossil specimens isolated through the hot acetolysis of the rock samples collected across the Permian-Triassic boundary at Chongyang section. Twenty species of 6 genera are found to occur in the limestone of Changxing Formation, and 11 species of 7 genera above the main faunal mass extinction horizon. The os-tracod assemblages identified at the Chongyang section are obviously different from those previously reported in the contem-poraneous microbialites in Guangxi and Chongqing regions, not only in the ostracod components but also in the abundance of filter-feeding ostracods relative to the deposit-feeding ostracods, an indicator of the oxygen level of the seawater. This spatial difference in ostracod assemblages might reflect the diversity of oceanic environmental conditions after the end-Permian mass extinction. Ostracods disappear at 200 cm below and near the main mass extinction horizon, and on the top of the microbialites, respectively, showing an episodic and gradual collapse process at the Chongyang section. The carbon isotope composition is found to appear at 200 cm below the main mass extinction horizon, indicating the initial deterioration of oceanic environment. Fluctuation of the carbon isotope composition is obviously related with the episodic evolution of ostracod species, but not with the abundance of ostracods.

  18. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mohd-Arrabe' , A. B.; Noraini, Talip Noraini [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2013-11-27

    Rhizophora L. are common mangrove genus in Peninsular Malaysia, it contains 3 species and 1 hybrid (R. apiculata Blume, R. mucronata Lam., R. stylosa Griff., R. x lamarckii Montrouz). This genus has some unique adaptation towards extreme environment. Rhizophora has looping aerial stilt-root and uniformly viviparous. The aim of this study is to investigate the variation in the pollen morphology of Rhizophora that can be related to their habitat. Methods include in this study is pollen observation under light and acetolysis method under scanning electron microscope. Pollen type of Rhizophora species studied except hybrid species is classified tricolporate, shape spheroidal based on ratio of length polar axis/ length of equatorial axis (1.03 - 1.09). The exine ornamentation is perforate-reticulate for R. apiculata and R. mucronata, while R. stylosa is perforate. For the only hybrid in Peninsular Malaysia, R. x lamarckii (R. apiculata x R. stylosa) differs from others, tricolpate with the absence of porate, shape is subprolate and exine ornamentation is reticulate and striate in equatorial region. Pollenkitt is present due to the salty and extreme environment. This may enhance the volume of pollenkitt present surrounding the pollen grains in Rhizophora for protection and adaptation purposes. Based on these findings, it is evident that pollen morphology is somehow related to its natural habitat.

  19. MORPHOLOGICAL, ANATOMICAL, CYTOLOGICAL AND PALYNOLOGICAL CHARACTERIZATION OF TWO CULTIVARS OF ABELMOSCHUS MOSCHATUS (L. MEDIK (MALVACEAE

    Directory of Open Access Journals (Sweden)

    Dubey Kumari Priyanka

    2011-02-01

    Full Text Available Seeds of 2 cultivars (cultivars I: seed moisture content 3.5%, 100 seed weight 1.94 gm ± 0.03, seed size 3.47 mm ± 0.08 × 3.20 mm ± 0.06; cultivars II: seed moisture content 1.5%, 100 seed weight 1.25 gm ± 0.01, seed size 2.92 mm ± 0.07 × 3.33 mm ± 0.03 of Abelmoschus moschatus (L. Medik (Family: Malvaceae were grown in the Experimental plots of University of Kalyani (West Bengal plain; 22°99´ N, 88°45´ E, elevation 48 feet above sea level, sandy loamy soil, organic carbon 0.76%, soil pH 6.85 during the rainfed seasons of 2009 and 2010 (July to December and morphological (taxonomical details, anatomical (transverse sections of ovary, stem and root, stomatal, cytological (meiotic chromosome behavior and pollen attributes (fertility, viability and acetolysis studies were assessed. Results indicated marked differences between the cultivars and based on observations cultivar I is recommended as tall, branched whereas cultivar II as dwarf, unbranched types and the cultivars may further be explored for pharmacological research.

  20. Neighboring group participation in solvolysis, 13

    International Nuclear Information System (INIS)

    Carbon-14 kinetic isotope effects (k12/k14) were determined for the solvolysis of phenethyl (1a) and 2-(p-methoxyphenyl)ethyl (1b) p-nitrobenzenesulfonates in acetic, formic, and trifluoroacetic acids. Phenyl-1 carbon effects were all in the range of 1.02 - 1.04 except for the acetolysis of 1a (k12/k14 = 1.005), which has been proved to proceed mainly via the aryl unassisted (k sub(s)) pathway. In all other reactions, which proceed mainly via the aryl assisted (k sub(Δ)) pathway, the phenyl-1 carbon apparently changes its bonding in the transition states. A large α-carbon effect (1.131) and a small β-carbon effect (1.013) as well as a mediumphenyl-1 effect (1.022) were observed for the formolysis of 1b, whose mechanism is thought to be exclusive k sub(Δ) without troublesome ion-pair return. These observations, together with α- and β-deuterium effects reported already, enabled us to describe the qualitative nature of the bridged transition-state structure of the k sub(Δ) pathway, i.e., advanced C sub(α)-O bond rupture, slight C sub(α)-C sub(Ph-1) bond formation, C sub(α)-C sub(β) double bond formation, slight C sub(β)-C sub(Ph-1) bond rupture, and breakdown of aromaticity at the phenyl-1 position. These characteristics are very similar to those of the phenonium ion. (author)

  1. Nesting biology of an Oriental carpenter bee, Xylocopa (Biluna nasalis Westwood, 1838, in Thailand (Hymenoptera, Apidae, Xylocopinae

    Directory of Open Access Journals (Sweden)

    Watcharapong Hongjamrassilp

    2014-12-01

    Full Text Available The biological study of wild non-Apis bees can provide useful information that may help with the pollination of food crops and native plants in areas where the keeping of honey bee colonies is restricted or affected by CCD. Here, we describe the nesting biology of the Oriental large carpenter bee, Xylocopa (Biluna nasalis Westwood, 1838. An aggregation of more than 80+ bamboo nests of X. nasalis was discovered in Suan Pheung district, Ratch Buri province, Thailand on the 25th of May 2012. We collected 27 nests from the site to dissect, measure the external and internal nest architecture, and analyze the pollen composition of the pollen masses. X. nasalis constructs linear unbranched nests with nest entrance mostly located at the open-end of the bamboo culms. The nest length and the branch diameter of the nest entrance (excluding nesting edge are 25.40 ± 6.95 cm and 17.94 ± 6.00 mm, and the maximum number of provisioned cells is 8. A biased sex ratio of 8♀: 1♂ is reported, with up to 7 adults inhabiting in a single nest. 29 pollen types were identified from 14 pollen masses using an acetolysis method and visualization under both light microscope and scanning electron microscope. 13 pollen types were considered as major pollen sources (contribute ≥ 1% in total pollen volume; however, only 10 can be identified to family and generic levels. The dominant pollen sources are of the families Elaeagnaceae (Elaeagnus cf. latifolia, Euphorbiaceae (Croton, Fabaceae (Senna siamea and Cassia, Fagaceae (Lithocarpus and Castanopsis, and Lythraceae (Trapa which are mostly native to the region of Southeast Asia. The nesting architectural details should prove to be beneficial to beekeepers and researchers who are interested in trapping and studying X. nasalis, and the polylectic behavior of X. nasalis can be highly valuable for future crop pollination strategies, particularly for plants that require sonication of their poricidal anthers.

  2. Givetian ostracods of the Candás Formation (Asturias, North-western Spain): taxonomy, stratigraphy, palaeoecology, relationship to global events and palaeogeographical implications.

    Science.gov (United States)

    Maillet, Sebastien; Milhau, Bruno; Vreulx, Michel; Posada, Luis-Carlos Sánchez De

    2016-01-01

    Asturian ostracods of the Givetian carbonate Candás Formation are documented for the first time from the Peran-Perlora and Carranques reference sections. More than 1,200 specimens were extracted from 44 samples by means of the hot acetolysis method. In all, 75 taxa are described herein, of which 21 are formally described and one, Evlanella peranensis Maillet n. sp., is new. All the taxa are marine benthic and belong to the Eifelian Mega-Assemblage. The assemblages recognized are representative of semi-restricted to shallow open-marine palaeoenvironments above the storm wave base. The stratigraphical distribution of the taxa shows a strong faunal renewal in the top of the Candás Formation. Long-ranging taxa found at the base of the formation, of which many are known from the base of the Middle Devonian, disappear within the base of the member C and are replaced above, around the Middle/Upper Givetian boundary, by more cosmopolitan taxa characteristic of the Frasnian. The lower half of the member C is also characterized both by unstable environments and occurrence of some short-ranging opportunistic ostracod taxa. This renewal within shallow water ostracod communities is probably a consequence of the global Taghanic Biocrisis, leading world-widely to extinctions in several faunal groups. Faunal affinities with Givetian ostracod taxa reported in other areas of the world reflect the commonly accepted palaeogeographical patterns. Close relations between the Cantabrian Zone (NW-Spain), the Armorican Massif (W-France), the Mouthoumet Massif (S-France) and North Africa (Morocco and Algeria) suggest a narrow oceanic space between the western European terranes and the northern Gondwanan margin that involves an advanced phase of closure of the Medio-European Ocean. PMID:27395904

  3. Botanical profile of bee pollen from the southern coastal region of Bahia, Brazil Perfil botânico do pólen apícola proveniente do litoral sul da Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Marcos da Costa Dórea

    2010-09-01

    Full Text Available This paper aims to identify the botanical origin of pollen loads collected by Apis mellifera L. in Canavieiras municipality, Bahia state. It provides a list of polliniferous plant species from the Atlantic Forest biome that are important for the development of regional apiculture. Using the acetolysis method, 35 bee-pollen samples were analyzed qualitatively and quantitatively. Results showed that pollen types Elaeis (23.99%, Mimosa pudica (22.78% and Cecropia (13.68% were the most abundant among the samples. These also showed the highest relative frequencies of the material studied and were important pollen sources for bees in the study area.O presente trabalho teve por objetivo identificar a origem botânica das bolotas de pólen coletadas pelas abelhas Apis mellifera L. no município de Canavieiras, Bahia, gerando uma lista de plantas poliníferas pertencentes ao bioma Mata Atlântica e importantes para o desenvolvimento da apicultura regional. Foram analisadas palinologicamente 35 amostras de pólen apícola, utilizando-se o processo de acetólise para, em seguida, serem feitas análises qualitativas e quantitativas. Os resultados revelaram que os tipos polínicos Elaeis (23,99%, Mimosa pudica (22,78% e Cecropia (13,68% foram os mais abundantes no pólen apícola analisado. Estes tipos polínicos também apresentaram as maiores frequências relativas de todo o material estudado e representam importantes plantas fontes de pólen para as abelhas na área estudada.

  4. Trans-α-xylosidase, a widespread enzyme activity in plants, introduces (1→4)-α-d-xylobiose side-chains into xyloglucan structures.

    Science.gov (United States)

    Franková, Lenka; Fry, Stephen C

    2012-06-01

    Angiosperms possess a retaining trans-α-xylosidase activity that catalyses the inter-molecular transfer of xylose residues between xyloglucan structures. To identify the linkage of the newly transferred α-xylose residue, we used [Xyl-(3)H]XXXG (xyloglucan heptasaccharide) as donor substrate and reductively-aminated xyloglucan oligosaccharides (XGO-NH(2)) as acceptor. Asparagus officinalis enzyme extracts generated cationic radioactive products ([(3)H]Xyl·XGO-NH(2)) that were Driselase-digestible to a neutral trisaccharide containing an α-[(3)H]xylose residue. After borohydride reduction, the trimer exhibited high molybdate-affinity, indicating xylobiosyl-(1→6)-glucitol rather than a di-xylosylated glucitol. Thus the trans-α-xylosidase had grafted an additional α-[(3)H]xylose residue onto the xylose of an isoprimeverose unit. The trisaccharide was rapidly acetolysed to an α-[(3)H]xylobiose, confirming the presence of an acetolysis-labile (1→6)-bond. The α-[(3)H]xylobiitol formed by reduction of this α-[(3)H]xylobiose had low molybdate-affinity, indicating a (1→2) or (1→4) linkage. In NaOH, the α-[(3)H]xylobiose underwent alkaline peeling at the moderate rate characteristic of a (1→4)-disaccharide. Finally, we synthesised eight non-radioactive xylobioses [α and β; (1↔1), (1→2), (1→3) and (1→4)] and found that the [(3)H]xylobiose co-chromatographed only with (1→4)-α-xylobiose. We conclude that Asparagus trans-α-xylosidase activity generates a novel xyloglucan building block, α-d-Xylp-(1→4)-α-d-Xylp-(1→6)-d-Glc (abbreviation: 'V'). Modifying xyloglucan structures in this way may alter oligosaccharin activities, or change their suitability as acceptor substrates for xyloglucan endotransglucosylase (XET) activity. PMID:22425285

  5. 赤芝孢子粉中一个葡聚糖的分离纯化与结构鉴定%Isolation and Structural Determination of a Glucan from the Spores of Ganoderma lucidum

    Institute of Scientific and Technical Information of China (English)

    鲍幸峰; 方积年

    2001-01-01

    A water soluble, (1→6)-branched, (1→4) linked D-glucan (LB-B1),[α]21D=+174.2° (c 0.87, H2O), was obtained from a hot-water extract of the sporoderm-broken spores of Ganoderma lucidum (Fr.) Karst by HPSEC, with 0.001 mol/L sodium hydroxide as the eluant, the molecular weight (Mw) of LB-B1 was estimated to be 9.3×103. From the results of total hydrolysis, methylation analysis, acetolysis and 1D, 2D-NMR experimentation, it was concluded that LB-B1 was composed of repeating units with the following structure:%从破壁的赤芝(Ganodermalucidum(Fr.)Karst)孢子粉中分离纯化到一个水溶性的、以1,4连接的D-葡萄糖为主链、在6位接1,6连接葡萄糖的α-D-葡聚糖。高效分子排阻色谱测定,重均分子量为9.3×103,[α]21D=+174.2°(c0.87,H2O)。通过糖组成分析,甲基化反应,乙酰解及一维和二维核磁等光谱解析,确定其结构如下:

  6. Diversidad de orbículas en Poaceae

    Directory of Open Access Journals (Sweden)

    Marcelo R Lovisolo

    2012-06-01

    Full Text Available Anteras de diez especies de Poaceae de la Provincia de Buenos Aires (Argentina fueron investigadas con microscopio electrónico de barrido y de transmisión. Las orbículas pueden ser definidas como corpúsculos de tamaño variable que muestran la misma electrodensidad, reacción a los colorantes, autofluorescencia y resistencia a la acetólisis que la exina del grano de polen. Las orbículas se encuentran revistiendo el interior del lóculo de la antera, a menudo adheridas a una membrana tapetal. En este estudio se identificaron cuatro tipos y cuatro subtipos diferentes de orbículas. Se concluye que los distintos tipos morfológicos de orbículas descriptos en este trabajo son representativos de cada una de las tribus estudiadas, por lo que se sugiere que la morfología de estos corpúsculos podría ser un carácter utilizado en estudios sistemáticos.Orbicules diversity in Poaceae. Anthers of ten species of Poaceae from the province of Buenos Aires (Argentina were investigated with scanning and transmission electron microscopes. The orbicules can be defined as corpuscles of variable size that show the same electron-density, reaction to the dyes, autofluorescence and resistance to acetolysis as pollen exine does. The orbicules are randomly dispersed on the inner anther locule and they are often attached to a tapetal membrane. In this study, four different types and four subtypes of orbicules were identified. We conclude that the different orbicules types described in this work are representative of the studied tribes, and we suggest that the orbicules morphology may be a useful character in systematic studies.

  7. Palynological characteristics of the heterostylous subspecies of Linum mucronatum Bertol

    Directory of Open Access Journals (Sweden)

    Talebi, S. M.

    2014-12-01

    Full Text Available Linum mucronatum is a heterostylous species from sect. Syllinum with four subspecies in Iran. The present study examines palynological characteristics of the heterostylous subspecies of Linum mucronatum, pollen characters of brevistylous individuals (pins as well as longistylous individuals (thrums of these plants by scanning electron microscope and light microscope using the prolonged acetolysis procedure. Sixteen qualitative and quantitative characters were investigated. Pollen equatorial shapes varied between pin and thrum individuals of each subspecies with the exception of L. mucronatum subsp. assyriacum. Pollen sculptures varied between pin and thrum samples of each subspecies and were seen in the gemmate, clavate and baculate shapes. In addition, quantitative palynological characters differed between plants and ANOVA test showed significant variations for traits such as equatorial length, colpi width and apocolpium diameter. Hetrostylous individuals of each subspecies were separated from others in the UPGMA tree and also in the PCO and PCA plots. This study confirmed variations in pollen features between pin and thrum individuals of each subspecies.Linum mucronatum es una especie con heterostilia, que pertenece a la sección Syllinum del género Linum, y tiene cuatro subespecies en Irán. En el presente estudio se examinan las características palinológicas de las subespecies heterostilas de Linum mucronatum Bertol., así como los caracteres polínicos de individuos de los morfos brevistilo (pin y longistilo (thrum de estas plantas, mediante microscopía electrónica de scanning y microscopía óptica usando el método de acetolisis prolongada. Se estudiaron un total de 16 caracteres cualitativos y cuantitativos. La forma ecuatorial del polen varía entre los morfos pin y thrum en todas las subspecies, excepto en L. mucronatum subsp. assyriacum. La ornamentación también varía entre las muestras de morfos pin y thrum de cada subespecie

  8. Pollen analysis in honey samples from the two main producing regions in the Brazilian northeast

    Directory of Open Access Journals (Sweden)

    Geni da S. Sodré

    2007-09-01

    Full Text Available Knowledge about the botanical source of honey is very important for the beekeeper while it indicates adequate and abundant supply sources of nectar and pollen for the bees, thus contributing toward improved yield. The present study means to identify the pollen types occurring in 58 samples of honey produced in two states of the northeastern region of Brazil, Piauí (38 samples and Ceará (20 samples, and to verify the potential of the honey plants during the months of February to August. The samples were obtained directly from beekeepers in each state and analyzed at the Apiculture Laboratory of the Entomology Section of Escola Superior de Agricultura "Luiz de Queiroz", USP, Piracicaba, State of São Paulo, Brazil. The pollen analysis was performed using the acetolysis method. The samples were submitted to both a qualitative and a quantitative analysis. The dominant pollen in the State of Ceará is from Mimosa caesalpiniaefolia, M. verrucosa, Borreria verticillata, Serjania sp., and a Fabaceae pollen type, while in the State of Piauí it is from Piptadenia sp., M. caesalpiniaefolia, M. verrucosa, Croton urucurana and Tibouchina sp.O conhecimento da origem botânica do mel é de grande importância para o apicultor por indicar fontes adequadas e de abundante suprimento de néctar e pólen para as abelhas, contribuindo, desta forma, para uma melhor produção. O presente estudo teve como objetivo identificar os tipos polínicos em 58 amostras de méis produzidos em dois estados da região nordeste do Brasil, Piauí (38 amostras e Ceará (20 amostras, verificando o potencial das plantas apícolas durante os meses de fevereiro a agosto. As amostras foram obtidas diretamente de apicultores de cada Estado e analisadas no Laboratório de Apicultura do Setor de Entomologia da Escola Superior de Agricultura "Luiz de Queiroz", USP, Piracicaba, Estado de São Paulo. A análise polínica foi realizada utilizando-se o método da acetólise. As amostras foram

  9. The Influence of Garden Size and Floral Cover on Pollen Deposition in Urban Community Gardens

    Directory of Open Access Journals (Sweden)

    Kevin C. Matteson

    2009-01-01

    Full Text Available Many cucurbits, such as cucumbers, squashes and pumpkins, depend on pollinating bees in order to set fruit. However, fruit yield and progeny vigor in these plants generally decreases as heterospecific pollen deposition increases. We studied how the spatial area dedicated to cucumbers (Cucumis sativis, versus other flowering plants, influenced the deposition of conspecific and heterospecific pollen on cucumber plants in New York City community gardens. We also examined the effect of garden size on conspecific and heterospecific pollen deposition on cucumber plants. Female flowers were collected from potted cucumber plants that had been experimentally placed into the gardens, specifically for this study, or that were established in raised beds by members of the community garden. In the laboratory, pollen grains were isolated from the flower by acetolysis, and the number of heterospecific and conspecific cucumber pollen grains were quantified. Conspecific pollen deposition was positively and significantly associated with the size of a community garden, as well as with the area of each garden dedicated to non-cucumber, flowering plants (i.e. floral cover and the area of each garden dedicated to cucumber plants (i.e. cucumber cover. Although floral cover explained a greater proportion of the variance, cucumber cover had the strongest effect on conspecific pollen deposition. Heterospecific pollen deposition was positively and significantly related to garden area. However, no significant relationship was found between heterospecific pollen deposition and floral cover, or cucumber cover. Based upon these results, we hypothesize that floral cover positively impacts conspecific pollen deposition by attracting a greater number of pollinators into an urban garden, and that total cucumber area positively impacts conspecific pollen deposition when pollinators are locally foraging within a garden. We suggest that the arrangement of plants within a garden can

  10. Palinomorfos de fungos e criptógamas em sedimentos quaternários de duas matas com Araucária, Planalto leste do Rio Grande do Sul, Brasil Palynomorphs of fungi and cryptogams in Quaternary sediments from two Araucaria forests, Eastern Plateau of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Caroline Scherer

    2008-03-01

    HCl, HF, KOH, acetolysis and slide mounts in glycerol-jelly. Light microscopy was used in the analysis. Palynomorphs of eight fungi, six algae, five bryophytes and 19 pteridophytes are presented. The description of each palynomorph is followed by illustrations and, whenever possible, by ecological data from the original organism. Distinct palynomorphs preserved in the sediments reveal the potential of this material in providing relevant environmental information, in association with pollen grains, in the study of genesis and expansion of the Araucaria forest.

  11. Levantamento da flora apícola em Santa Luzia do Paruá, Sudoeste da Amazônia, Maranhão Survey of bee flora in Santa Luzia do Paruá, Southwest Amazonia, Maranhão

    Directory of Open Access Journals (Sweden)

    Luiz Junior Pereira Marques

    2011-03-01

    Full Text Available Foi realizado o levantamento das plantas visitadas por Apis mellifera L. através de análise polínica no município de Santa Luzia do Paruá, Maranhão, localizado a noroeste do Estado, em região amazônica. A temperatura média anual varia entre 26 °C e 27 °C, com umidade relativa do ar anual entre 79 a 82% e precipitação pluviométrica entre 2000 a 2400 mm anuais. O estudo foi conduzido entre agosto de 2005 e julho de 2006 em três apiários da região, com coletas mensais de mel, pólen e plantas, que foram submetidas ao método de acetólise. Os tipos polínicos das amostras de mel foram identificados e contados para a determinação da freqüência relativa média. Nas amostras de pólen foi realizada apenas a identificação dos tipos polínicos por meio da comparação com os polens das plantas (botões florais depositados em coleção de referência. As principais famílias utilizadas por A. mellifera foram Amaranthaceae, Arecaceae, Asteraceae, Urticaceae, Euphorbiaceae, Lamiaceae, Fabaceae-Mimosoideae, Flacourtiaceae, Myrtaceae, Poaceae e Rubiaceae. Em amostras de mel, no período chuvoso destacaram-se os tipos polínicos de Mimosa pudica, Borreria e um tipo indeterminado da família Arecaceae. No período de safra foram representativos Hyptis e um tipo indeterminado de Asteraceae. Os tipos polínicos mais constantes nas amostras de pólen foram Euterpe oleracea, Asteraceae tipo 1, Mimosa pudica e Borreria.The plant species visited by Apis mellifera L. were surveyed by pollen analysis in Santa Luzia do Paruá municipality, located in northwestern Maranhão state. Natural vegetation is Amazon rainforest, mean annual temperature varies between 26°C and 27°C, relative air humidity between 79 and 82%, and total rainfall between 2000 and 2400 mm. This study was conducted from August 2005 to July 2006 in three apiaries of the region, with monthly sampling of honey, pollen and plants. The samples were analyzed by the acetolysis method

  12. Proterozoic microfossils revealing the time of algal divergences

    Science.gov (United States)

    Moczydlowska-Vidal, Malgorzata

    2010-05-01

    Proterozoic microfossils revealing the time of algal divergences Małgorzata Moczydłowska-Vidal Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, SE 752 36 Uppsala, Sweden (malgo.vidal@pal.uu.se) Morphological and reproductive features and cell wall ultrastructure and biochemistry of Proterozoic acritarchs are used to determine their affinity to modern algae. The first appearance datum of these microbiota is traced to infer a minimum age of the divergence of the algal classes to which they may belong. The chronological appearance of microfossils that represent phycoma-like and zygotic cysts and vegetative cells and/or aplanospores, respectively interpreted as prasinophyceaen and chlorophyceaen microalgae, is related to the Viridiplantae phylogeny. These divergence times differ from molecular clock estimates, and the palaeontological evidence suggests that they are older. The best examples of unicellular, organic-walled microfossils (acritarchs) from the Mesoproterozoic to Early Ordovician are reviewed to demonstrate features, which are indicative of their affinity to photosynthetic microalgae. The first indication that a microfossil may be algal is a decay- and acid-resistant cell wall, which reflects its biochemistry and ultrastructure, and probably indicates the ability to protect a resting/reproductive cyst. The biopolymers synthesized in the cell walls of algae and in land plants ("plant cells"), such as sporopollenin/algaenan, are diagnostic for photosynthetic taxa and were inherited from early unicellular ancestors. These preservable cell walls are resistant to acetolysis, hydrolysis and acids, and show diagnostic ultrastructures such as the trilaminar sheath structure (TLS). "Plant cell" walls differ in terms of chemical compounds, which give high preservation potential, from fungal and animal cell walls. Fungal and animal cells are fossilized only by syngenetic permineralization, whereas "plant cells" are fossilized as body

  13. Morphology and pollen viability of Lolium multiflorum Lam. Morfologia e viabilidade polínica de Lolium multiflorum Lam.

    Directory of Open Access Journals (Sweden)

    Renata de Castro Nunes

    2012-04-01

    Full Text Available Study and characterization of pollen grains are essential for different areas, especially taxonomy, genetic improvement, phylogeny, and paleobotany. As yet, there are no reports on pollen morphology of genotypes of naturalized Lolium multiflorum Lam., introduced cultivars or breeding populations, diploid or polyploid. Ten genotypes of annual ryegrass (L. multiflorum were evaluated for the viability of pollen grains using propionic carmine and Alexander's stains, while morphology was assessed by the acetolysis technique. Measures of polar axis (P, equatorial diameter (E, exine thickness, and analysis of pollen grains were obtained by scanning electron microscopy (SEM. All genotypes showed high rate of pollen viability (> 89% for both stains. There were differences between genotypes in the following quantitative traits: polar axis, equatorial diameter, exine, endexine, ektexine, and P/E ratio. Pollen grains were characterized as small, monoporates, with circular and non-prominent apertures. In addition to helping distinction of pollen grains, morphometric differences can be used later to compare ploidy levels, thus assisting in breeding programs of the species.O estudo e a caracterização do grão de pólen são fundamentais para diferentes áreas, em especial, para a taxonomia, o melhoramento genético, a filogenia e a paleobotânica. Para genótipos de Lolium multiflorum Lam., naturalizados no Brasil, cultivares introduzidas ou populações de melhoramento, diploides e poliploides, não existem relatos sobre a caracterização morfopolínica. Nesse trabalho foram analisados dez gentótipos de azevém anual (L. multiflorum. A viabilidade dos grãos de pólen foi verificada por coloração com os corantes carmim propiônico e Alexander e a morfologia por meio da técnica de acetólise, sendo obtidas medidas do eixo polar (P, do diâmetro equatorial (E, e da espessura da exina, e análise dos grãos de pólen por microscopia eletrônica de