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Sample records for quercus suber em

  1. Volatile Organic Compound Emission from Quercus suber, Quercus canariensis, and its hybridisation product Quercus afares

    Science.gov (United States)

    Welter, S.; Bracho Nuñez, A.; Staudt, M.; Kesselmeier, J.

    2009-04-01

    Oaks represent one of the most important plant genera in the Northern hemisphere and include many intensively VOC emitting species. The major group constitutes the isoprene emitters, but also monoterpene emitters and non-emitters can be found. These variations in the oak species might partly be due to their propensity for inter- and intraspecific hybridisation. This study addresses the foliar VOC production of the former hybridisation product the deciduous Quercus afares and its parents, two very distant species: the evergreen monoterpene emitter Quercus suber and the deciduous isoprene emitter Quercus canariensis. The measurements were performed in Southern France, applying two different methods. Plants were investigated in situ in the field with a portable gas exchange measuring system as well as in the laboratory on cut branches with an adapted enclosure system. Quercus afares was found to be a monoterpene emitting species. However, the monoterpene emission was lower and the composition different to that of Quercus suber. Whereas Quercus suber trees belonged to the pinene type most individuals of Quercus afares were identified to represent a limonene type. Quercus canariensis emitted besides high amounts of isoprene also linalool and (Z)-3-hexenylacetate. Emissions from Quercus suber and Quercus afares were higher in the field measurements than in the laboratory on cut branches whereas Quercus canariensis exhibited lower isoprene emissions from cut branches. The results demonstrate the need of further emission studies on a plant species level.

  2. Cork Oak Trees (Quercus suber L.).

    Science.gov (United States)

    Alvarez, Rubén; Toribio, Mariano; Cortizo, Millán; Ordás Fernández, Ricardo-Javier

    2006-01-01

    A transformation system for selected mature Quercus suber L. trees using Agrobacterium tumefaciens has been established. Embryos obtained from recurrent proliferating embryogenic masses are inoculated with AGL1 strain harbouring the plasmid pBINUbiGUSint, which carries the nptII and uidA genes. Evidence of stable transgene integration is obtained by polymerase chain reaction for nptII and uidA genes, Southern blotting and expression of the uidA gene. The transgenic embryos are germinated and successfully transferred to soil.

  3. Phylogeographical Variation of Chloroplast DNA in Cork Oak (Quercus suber)

    OpenAIRE

    Lumaret, Roselyne; TRYPHON-DIONNET, MATHIEU; MICHAUD, HENRI; SANUY, AURÉLIE; IPOTESI, EMILIE; Born, Céline; MIR, CÉLINE

    2005-01-01

    • Background and Aims In the last decades, the geographical location of the centre of origin of Quercus suber (cork oak), a strictly western Mediterranean oak species, has been the subject of controversy.

  4. Flower Bud Differentiation in Quercus suber L.

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    Maria Carolina Varela

    2016-06-01

    Full Text Available Background and Purpose: Cork oak (Quercus suber L. is one of the most important forest species growing in the Western Mediterranean region. This investigation intends to assess the timing of flowering differentiation of cork oak and contribute to the deepening of the knowledge about the process of the sexual reproduction of the species. Materials and Methods: In 2010 four trees were selected (9, 14, 24, 25 from a plot of 25 trees located at Quinta da Serra, Portugal. A total of 240 buds were collected from these four trees, on three days (8, 14 and 23 March, from 4 branches per tree and 5 positions per branch for the assessment of meristem differentiation. Results: Meristem differentiation analysed on the sampling days revealed there were only vegetative structures by 8 March; a few male and female primordia on 14 March; and fully differentiated reproductive structures on 23 March. Conclusions: Flowering sex determination of cork oak occurs about one month before the flowering onset.

  5. Cork oak (Quercus suber L.) seedlings acclimate to elevated

    OpenAIRE

    2012-01-01

    Leaf gas-exchange, leaf and shoot anatomy, wood density and hydraulic conductivity were investigated in seedlings of Quercus suber L. grown for 15 months either at elevated (700 lmol mol-1) or normal (350 lmol mol-1) ambient atmospheric CO2 concentrations. Plants were grown in greenhouses in a controlled environment: relative humidity 50% (±5), temperature similar to external temperature and natural light conditions. Plants were supplied with nutrients and two water re...

  6. Dimeric and trimeric hydrolyzable tannins from Quercus coccifera and Quercus suber.

    Science.gov (United States)

    Ito, Hideyuki; Yamaguchi, Koji; Kim, Tae-Hoon; Khennouf, Seddik; Gharzouli, Kamel; Yoshida, Takashi

    2002-03-01

    Three new hydrolyzable tannins, cocciferins D(1) (1), D(2) (2), and T(1) (4), were isolated from the leaves of Quercus coccifera. Cocciferin D(2) (2) and two additional new tannins, cocciferins D(3) (3) and T(2) (5), were also obtained from the leaves of Quercus suber. Their oligomeric structures were elucidated on the basis of spectroscopic methods and chemical evidence. Compounds 2, 3, and 5 were rare oligomers possessing glucose cores with both open-chain and pyranose forms.

  7. Antimutagenicity of a suberin extract from Quercus suber cork.

    Science.gov (United States)

    Krizková, L; Lopes, M H; Polónyi, J; Belicová, A; Dobias, J; Ebringer, L

    1999-12-13

    The possible protective effect of a suberin extract from Quercus suber cork on acridine orange (AO)-, ofloxacin- and UV radiation-induced mutagenicity (bleaching activity) in Euglena gracilis was examined. To our knowledge, the present results are the first attempt to analyse suberin in relation to mutagenicity of some chemicals. Suberin exhibits a significant dose-dependent protective effect against AO-induced mutagenicity and the concentration of 500 micrograms/ml completely eliminates the Euglena-bleaching activity of AO. The mutagenicity of ofloxacin is also significantly reduced in the presence of suberin (125, 250 and 500 micrograms/ml). However, the moderate protective effect of suberin on UV radiation-induced mutagenicity was observed only at concentrations 500 and 1000 micrograms/ml. Our data shows that suberin extract from Q. suber cork possess antimutagenic properties and can be included in the group of natural antimutagens acting in a desmutagenic manner.

  8. Resprouting of Quercus suber in NE Spain after fire

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    Pausas, J.G. [Centro de Estudios Ambientales del Mediterraneo, Valencia (Spain)

    1997-11-01

    Many Mediterranean species have evolved strategies that allow them to survive periodic wildfires. Quercus suber trees resprout after fire, some from stem buds and others from basal buds only. In the former case the canopy recovers quickly. In the latter case the stem dies but the tree survives and regrows from basal sprouts. The probability of stem death and the degree of height recovery were studied after a fire in a Q. suber forest in NE Spain using logistic regression analysis. The results suggest that most trees survive after fire; the probability of stem death is negatively related to tree diameter; and recovery is positively related to tree diameter and to bark thickness. Implication for management and conservation of cork-oak forests are discussed 22 refs, 2 figs, 3 tabs

  9. Improved genetic transformation of cork oak (Quercus suber L.).

    Science.gov (United States)

    Alvarez-Fernández, Rubén; Ordás, Ricardo-Javier

    2012-01-01

    An Agrobacterium-mediated transformation system for selected mature Quercus suber L. trees has been established. Leaf-derived somatic embryos in an early stage of development are inoculated with an AGL1 strain harboring a kanamycin-selectable plasmid carrying the gene of interest. The transformed embryos are induced to germinate and the plantlets transferred to soil. This protocol, from adult cork oak to transformed plantlet, can be completed in about one and a half years. Transformation efficiencies (i.e., percentage of inoculated explants that yield independent transgenic embryogenic lines) vary depending on the cork oak genotype, reaching up to 43%.

  10. SSR markers for Quercus suber tree identification and embryo analysis.

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    Gómez, A; Pintos, B; Aguiriano, E; Manzanera, J A; Bueno, M A

    2001-01-01

    Three Quercus simple sequence repeat (SSR) markers were amplified by polymerase chain reaction (PCR) from nuclear DNA extracts of trees and in vitro-induced haploid embryos from anther cultures of Quercus suber L. These markers were sufficiently polymorphic to identify 10 of 12 trees located in two Spanish natural areas. The same loci have been analyzed in anther-derived haploid embryos showing the parental tree allele segregation. All the alleles were present in the haploid progeny. The presence of diverse alleles in embryos derived from the same anther demonstrated that they were induced on multiple microspores or pollen grains and they were not clonally propagated. Also, diploid cultures and mixtures of haploid-diploid tissues were obtained. The origin of such cultures, either somatic or gametic, was elucidated by SSR markers. All the embryos showed only one allele, corroborating a haploid origin. Allelic composition of the haploid progeny permitted parental identification among all analyzed trees.

  11. Temperature stress effects in Quercus suber leaf metabolism.

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    Chaves, Inês; Passarinho, José António P; Capitão, Cláudio; Chaves, Maria Manuela; Fevereiro, Pedro; Ricardo, Cândido P P

    2011-10-15

    Based on projections that climate changes are will intensify in the near future, it is important to understand how plants respond to climate. Consequently, we have been studying the effect of contrasting temperatures on leaf metabolism of Quercus suber, an important Mediterranean oak. Potted plants were grown under controlled conditions for 53 days at 28°C or 10°C. The accumulation of major soluble metabolites was analyzed by NMR. The relative levels of transcripts of genes encoding key enzymes of the shikimate and phenylpropanoid pathway (CS, PAL, CAD and ChS) were examined by means of quantitative, real-time RT-PCR. At 10°C, in the pre-existing leaves, the concentrations of sucrose, quercitol and catechin were higher, as were PAL and ChS transcripts. At 28°C, however, it was the concentration of quinic acid that was higher, as were the concentrations of CS and CAD transcripts. We conclude that contrasting temperatures greatly influence Q. suber metabolism and that a deeper analysis of the effects of more extreme temperatures is needed to understand the possible effects of temperature changes on Q. suber metabolism and physiology.

  12. Large-scale patterns of Quercus ilex, Quercus suber, and Quercus pyrenaica regeneration in central-western Spain

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Rolo, Víctor; Moreno, Gerardo

    2010-01-01

    categories, from small seedlings to large saplings, and for the three oak species studied, especially the evergreens. Of the Quercus ilex, Q. suber, and Q. pyrenaica plots studied, 49%, 62%, and 20% were lacking any small seedlings, and 82%, 96%, and 56% did not have any large saplings, respectively......In Central-Western Spain, forests and woodlands composed of Quercus sp. support outstanding levels of biodiversity, but there is increasing concern about their long-term persistence due to a lack of regeneration. We hypothesize that this regenerative lack is operating on a large geographic scale...... and Q. suber were positively correlated with all understory variables, suggesting that the presence of pioneer shrubs represent a major safe site for early tree recruitment, independent from specific shrub species. © 2010 Springer Science+Business Media, LLC....

  13. Cryopreservation of Quercus suber and Quercus ilex embryonic axes: in vitro culture, desiccation and cooling factors.

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    Gonzalez-Benito, M Elena; Prieto, Roberto-Moreno; Herradon, Esther; Martin, Carmen

    2002-01-01

    This study examines different factors included in the cryopreservation protocols for Quercus ilex and Q. suber embryonic axes. In vitro incubation temperature played an important role in the appropriate development of Q. ilex axes, as 15 degrees C was superior to 25 degrees C. Q. suber axes proved to be more sensitive to desiccation and cooling. Poor survival (35%) was observed when axes were included into cryovials and then in liquid nitrogen, and none when immersed in sub-cooled liquid nitrogen (-210 degrees C). Q. ilex axes showed poorly organised development in vitro (c. 50% of non-cooled axes showed shoot development). However, c. 80% survival was observed after cryopreservation (either in liquid nitrogen or sub-cooled liquid nitrogen at 0.34 g water / g dry weight), of which c. 15% showed shoot development.

  14. Presence of env-like sequences in Quercus suber retrotransposons.

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    Carvalho, M; Ribeiro, T; Viegas, W; Morais-Cecilio, L; Rocheta, M

    2010-01-01

    The main difference between LTR retrotransposons and retroviruses is the presence of the envelope (env) gene in the latter, downstream of the pol gene. The env gene is involved in their infectious capacity. Here we report the presence of env-like sequences in the genome of Quercus suber (cork oak), one of the most economically important Portuguese species. These gene sequences were isolated through DNA amplification between RNaseH conserved motifs and 3' LTR, based on the structure of copia retrotransposons. Phylogenetic analysis revealed that almost all the clones isolated are clustered with Cyclops-2, a Ty3-gypsy element identified in Pisum sativum, except one clustered with gypsy and copia retroelements found in different species. This suggests the existence of a potential ancestral sequence of the env gene, prior to the separation of Ty3-gypsy and Ty1-copia retrotransposons. Additionally, the isolated env-like sequences showed 26-39% of homology with env-like sequences characterized in viruses. The origin of env-like sequences in retrotransposons from host plant taxa is discussed.

  15. The diversification of terpene emissions in Mediterranean oaks: lessons from a study of Quercus suber, Quercus canariensis and its hybrid Quercus afares.

    Science.gov (United States)

    Welter, Saskia; Bracho-Nuñez, Araceli; Mir, Céline; Zimmer, Ina; Kesselmeier, Jürgen; Lumaret, Roselyne; Schnitzler, Jörg-Peter; Staudt, Michael

    2012-09-01

    Interspecific gene flow is common in oaks. In the Mediterranean, this process produced geographical differentiations and new species, which may have contributed to the diversification of the production of volatile terpenes in the oak species of this region. The endemic North African deciduous oak Quercus afares (Pomel) is considered to be a stabilized hybrid between the evergreen Quercus suber (L.) and the deciduous Quercus canariensis (Willd.), presumably being monoterpene and isoprene emitters, respectively. In a common garden experiment, we examined the terpene emission capacities, terpene synthase (TPS) activities and nuclear genetic markers in 52 trees of these three oak species. All but one of the Q. suber and Q. canariensis trees were found to be genetically pure, whereas most Q. afares trees possessed a mixed genotype with a predominance of Q. suber alleles. Analysis of the foliar terpene emissions and TPS activities revealed that all the Q. canariensis trees strongly produced isoprene while all the Q. suber trees were strong monoterpene producers. Quercus afares trees produced monoterpenes as well but at more variable and significantly lower rates, and with a monoterpene pattern different than that observed in Q. suber. Among 17 individuals tested, one Q. afares tree emitted only an insignificant amount of terpenes. No mixed isoprene/monoterpene emitter was detected. Our results suggest that the capacity and pattern of volatile terpene production in Algerian Q. afares populations have strongly diverged from those of its parental species and became quantitatively and qualitatively reduced, including the complete suppression of isoprene production.

  16. Effect of tannins from Quercus suber and Quercus coccifera leaves on ethanol-induced gastric lesions in mice.

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    Khennouf, Seddik; Benabdallah, Hassiba; Gharzouli, Kamel; Amira, Smain; Ito, Hideyuki; Kim, Tae-Hoon; Yoshida, Takashi; Gharzouli, Akila

    2003-02-26

    The gastroprotective effects of 70% acetone extracts of Quercus suber and Quercus coccifera leaves and of tannins (pedunculagin, castalagin, phillyraeoidin A, and acutissimin B) purified from these extracts were examined in the mouse using the ethanol-induced gastric ulcer model. Both extracts (25, 50, and 100 mg/kg), given orally, prevented the formation of ethanol-induced lesions in the stomach. The percent protection varied between 68 and 91%. Purified tannins (50 mg/kg) were also effective in protecting the stomach against ethanol, and the percent protection varied from 66 to 83%. Castalagin was the most potent. Both extracts and all of the tannins tested (10, 25, and 50 microg/mL) strongly inhibited (55-65%) the lipid peroxidation of rabbit brain homogenate. These results suggest that the gastroprotective effects of extracts of Q. suber and Q. coccifera leaves and the purified tannins in this experimental model are related to their anti-lipoperoxidant properties.

  17. Identification of DNA-microsatellite markers for the characterization of somatic embryos in Quercus suber.

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    Gómez-Garay, Arancha; Bueno, Angeles; Pintos, Beatriz

    2013-01-01

    Nuclear DNA-microsatellite markers led the possibility to characterize individually both Quercus suber trees and somatic embryos. The genotype inferred by SSR markers opens the possibility to obtain a fingerprint for clonal lines identification. Furthermore, allow to infer the origin of somatic embryos from haploid cells (microspores) or from diploid tissues. Using few SSR markers from other Quercus species and an automatic system based in fluorescence, it is possible to obtain a high discrimination power between genotypes. This method is sufficient to assign tissues to an individual tree with high statistical certainty. Nevertheless, it is necessary to take care to select the adequate DNA extraction method to avoid PCR inhibitors present in diverse Q. suber tissues.

  18. A neighborhood analysis of the consequences of Quercus suber decline for regeneration dynamics in Mediterranean forests.

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    Ibáñez, Beatriz; Gómez-Aparicio, Lorena; Stoll, Peter; Ávila, José M; Pérez-Ramos, Ignacio M; Marañón, Teodoro

    2015-01-01

    In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber). Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis) were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species' relative abundance and canopy trees' health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current forests to shift into

  19. A neighborhood analysis of the consequences of Quercus suber decline for regeneration dynamics in Mediterranean forests.

    Directory of Open Access Journals (Sweden)

    Beatriz Ibáñez

    Full Text Available In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber. Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species' relative abundance and canopy trees' health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current

  20. Diurnal and seasonal emissions of volatile organic compounds from cork oak ( Quercus suber) trees

    Science.gov (United States)

    Pio, C. A.; Silva, P. A.; Cerqueira, M. A.; Nunes, T. V.

    The emissions of volatile organic compounds from Quercus suber (cork oak) were investigated at two rural sites in Portugal using a branch enclosure method with subsequent analysis by gas chromatography/flame ionization detection. Q. suber leaves released important amounts of monoterpenes, mainly in the form of limonene, α-pinene, β-pinene and sabinene. However, significant temporal and intraspecific variations in the relative abundance of the dominant compounds were found during this survey. Emissions from Q. suber were strongly dependent on light and temperature, showing a similar behaviour to that of plant species known to be isoprene producers. But, this work also revealed that, although at lower rates, emissions of monoterpenes continued in the dark for several hours. Emission rates were quite well predicted by algorithms based on the Guenther and Tingey equations; correlations of measurements with modelled data were, on average, r2=0.80. A pronounced seasonal variation was recorded for the emissions of monoterpenes. During the 1-yr study period, standard emission rates ranged between a minimum of 0.2 μg g dw-1 h -1, in winter, and a maximum of 20-30 μg g dw-1 h -1, in summer.

  1. Photosynthesis of Quercus suber is affected by atmospheric NH3 generated by multifunctional agrosystems.

    Science.gov (United States)

    Pintó-Marijuan, Marta; Da Silva, Anabela Bernardes; Flexas, Jaume; Dias, Teresa; Zarrouk, Olfa; Martins-Loução, Maria Amélia; Chaves, Maria Manuela; Cruz, Cristina

    2013-12-01

    Montados are evergreen oak woodlands dominated by Quercus species, which are considered to be key to biodiversity conservation and ecosystem services. This ecosystem is often used for cattle breeding in most regions of the Iberian Peninsula, which causes plants to receive extra nitrogen as ammonia (NH(3)) through the atmosphere. The effect of this atmospheric NH(3) (NH(3atm)) on ecosystems is still under discussion. This study aimed to evaluate the effects of an NH(3atm) concentration gradient downwind of a cattle barn in a Montado area. Leaves from the selected Quercus suber L. trees along the gradient showed a clear influence of the NH(3) on δ(13)C, as a consequence of a strong limitation on the photosynthetic machinery by a reduction of both stomatal and mesophyll conductance. A detailed study of the impact of NH(3atm) on the photosynthetic performance of Q. suber trees is presented, and new mechanisms by which NH(3) affects photosynthesis at the leaf level are suggested.

  2. Drought-induced photosynthetic inhibition and autumn recovery in two Mediterranean oak species (Quercus ilex and Quercus suber).

    Science.gov (United States)

    Vaz, M; Pereira, J S; Gazarini, L C; David, T S; David, J S; Rodrigues, A; Maroco, J; Chaves, M M

    2010-08-01

    Responses of leaf water relations and photosynthesis to summer drought and autumn rewetting were studied in two evergreen Mediterranean oak species, Quercus ilex spp. rotundifolia and Quercus suber. The predawn leaf water potential (Ψ(lPD)), stomatal conductance (gs) and photosynthetic rate (A) at ambient conditions were measured seasonally over a 3-year period. We also measured the photosynthetic response to light and to intercellular CO₂ (A/PPFD and A/C(i) response curves) under water stress (summer) and after recovery due to autumn rainfall. Photosynthetic parameters, Vc(max), J(max) and triose phosphate utilization (TPU) rate, were estimated using the Farquhar model. RuBisCo activity, leaf chlorophyll, leaf nitrogen concentration and leaf carbohydrate concentration were also measured. All measurements were performed in the spring leaves of the current year. In both species, the predawn leaf water potential, stomatal conductance and photosynthetic rate peaked in spring, progressively declined throughout the summer and recovered upon autumn rainfall. During the drought period, Q. ilex maintained a higher predawn leaf water potential and stomatal conductance than Q. suber. During this period, we found that photosynthesis was not only limited by stomatal closure, but was also downregulated as a consequence of a decrease in the maximum carboxylation rate (Vc(max)) and the light-saturated rate of photosynthetic electron transport (J(max)) in both species. The Vc(max) and J(max) increased after the first autumnal rains and this increase was related to RuBisCo activity, leaf nitrogen concentration and chlorophyll concentration. In addition, an increase in the TPU rate and in soluble leaf sugar concentration was observed in this period. The results obtained indicate a high resilience of the photosynthetic apparatus to summer drought as well as good recovery in the following autumn rains of these evergreen oak species.

  3. Frequent cytoplasmic exchanges between oak species that are not closely related: Quercus suber and Q. ilex in Morocco.

    Science.gov (United States)

    Belahbib, N; Pemonge, M H; Ouassou, A; Sbay, H; Kremer, A; Petit, R J

    2001-08-01

    Chloroplast (cp) and mitochondrial (mt) DNA variation were studied in 97 populations of cork oak (Quercus suber) in Morocco; in 31 of these populations, holm oak (Quercus ilex), a clearly distinct species, also occurred and was compared with Q. suber. Three cpDNA and one mtDNA primer pairs were used in the survey, each in combination with one restriction enzyme. Six haplotypes belonging to two very divergent lineages were detected; one lineage predominates in each species, and is probably ancestral, as inferred from comparisons with other oak species. In the mixed-species populations, cytoplasmic genomes were frequently shared across species, as indicated by an introgression ratio of 0.63. This index is a new measure of the propensity of species to share locally genetic markers, varying from zero (complete differentiation) to one (no differentiation). By contrast, more closely related deciduous oak species (Q. robur, Q. petraea and Q. pubescens) have introgression ratios varying from 0.82 to 0.97. The introgression events appear to have been more frequent in the direction Q. ilex (female) x Q. suber (male), a finding which seems attributable to the flowering phenology of these two species. This asymmetry may have favoured immigration of Q. suber beyond its main range, in regions already colonized by Q. ilex. There, rare hybridization and further introgression through long distance pollen flow have established populations that are morphologically indistinguishable from Q. suber but that have cytoplasmic genomes originating from the local Q. ilex populations.

  4. PHYTOGEOGRAPHY OF QUERCUS SUBER L. IN LAZIO (CENTRAL ITALY: A CAUSALISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    B. SCHIRONE

    2008-01-01

    Full Text Available A descriptive statistical approach to the causalistic distribution of Quercus suber in Lazio (Central Italy, based on presence/absence data and mean values of an array of environmental variables standardized on a geographical 6,9 x 5,5 Km grid, shows that only temperature, precipitation, elevation and slope are significant. At this scale, soil conditions and aspect are apparently no limiting factors to the colonization ability of the species. A simulated potential range, based on this parameterization, identifies a larger area than the one occupied by the species today. It suggests that competition and human disturbance might account for the large gaps and discontinuities in the real range. Since inland disjunct outposts still lie either outside or at the boundary of this simulated range, their establishment is likely to have originated under macroclimatic conditions different from the present day ones.

  5. PHYTOGEOGRAPHY OF QUERCUS SUBER L. IN LAZIO (CENTRAL ITALY: A CAUSALISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    F. SPADA

    2008-04-01

    Full Text Available A descriptive statistical approach to the causalistic distribution of Quercus suber in Lazio (Central Italy, based on presence/absence data and mean values of an array of environmental variables standardized on a geographical 6,9 x 5,5 Km grid, shows that only temperature, precipitation, elevation and slope are significant. At this scale, soil conditions and aspect are apparently no limiting factors to the colonization ability of the species. A simulated potential range, based on this parameterization, identifies a larger area than the one occupied by the species today. It suggests that competition and human disturbance might account for the large gaps and discontinuities in the real range. Since inland disjunct outposts still lie either outside or at the boundary of this simulated range, their establishment is likely to have originated under macroclimatic conditions different from the present day ones.

  6. Epigenetic marks in the mature pollen of Quercus suber L. (Fagaceae).

    Science.gov (United States)

    Ribeiro, Teresa; Viegas, Wanda; Morais-Cecílio, Leonor

    2009-03-01

    We have analysed the distribution of epigenetic marks for histone modifications at lysine residues H3 and H4, and DNA methylation, in the nuclei of mature pollen cells of the Angiosperm tree Quercus suber; a monoecious wind pollinated species with a protandrous system, and a long post-pollination period. The ultrasonic treatment developed for the isolation of pollen nuclei proved to be a fast and reliable method, preventing the interference of cell wall autofluorescence in the in situ immunolabelling assays. In contrast with previous studies on herbaceous species with short progamic phases, our results are consistent with a high level of silent (5-mC and H3K9me2) epigenetic marks on chromatin of the generative nucleus, and the prevalence of active marks (H3K9me3 and H4Kac) in the vegetative nucleus. The findings are discussed in terms of the pollination/fertilization timing strategy adopted by this plant species.

  7. Genetic transformation of selected mature cork oak (Quercus suber L.) trees.

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    Alvarez, R; Alonso, P; Cortizo, M; Celestino, C; Hernández, I; Toribio, M; Ordás, R J

    2004-10-01

    A transformation system for selected mature cork oak (Quercus suber L.) trees using Agrobacterium tumefaciens has been established. Embryos obtained from recurrent proliferating embryogenic masses were inoculated with A. tumefaciens strains EHA105, LBA4404 or AGL1 harbouring the plasmid pBINUbiGUSint [carrying the neomycin phosphotransferase II (nptII) and beta-glucuronidase (uidA) genes]. The highest transformation efficiency (4%) was obtained when freshly isolated explants were inoculated with A. tumefaciens strain AGL1. Evidence of stable transgene integration was obtained by PCR for the nptII and uidA genes, Southern blotting and expression of the uidA gene. The transgenic embryos were germinated and successfully transferred to soil.

  8. Quercus Suber L. Cork Extracts Induce Apoptosis in Human Myeloid Leukaemia HL-60 Cells.

    Science.gov (United States)

    Bejarano, Ignacio; Godoy-Cancho, Belén; Franco, Lourdes; Martínez-Cañas, Manuel A; Tormo, María A

    2015-08-01

    Quercus suber L. cork contains a diversity of phenolic compounds, mostly low molecular weight phenols. A rising number of reports support with convergent findings that polyphenols evoke pro-apoptotic events in cancerous cells. However, the literature related to the anti-cancer bioactivity of Q. suber L. cork extractives (QSE) is still limited. Herein, we aim to describe the antitumor potential displayed by cork extractives obtained by different extraction methods in the human promyelocytic leukaemia cells. In order to quantify the effects of QSE on cancer cells viability, phosphatidylserine exposure, caspase-3 activity, mitochondrial membrane potential and cell cycle were evaluated. The results indicated that the QSE present a time-dependent and dose-dependent cytotoxicity in the human promyelocytic leukaemia cells. Such a noxious effect leads these leukaemia cells to their death through apoptotic processes by altering the mitochondrial outer membrane potential, activating caspase-3 and externalizing phosphatidylserine. However, cells cycle progression was not affected by the treatments. This study contributes to open a new way to use this natural resource by exploiting its anti-cancer properties. Moreover, it opens new possibilities of application of cork by-products, being more efficient in the sector of cork-based agriculture. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Studies on the ectomycorrhizal community in a declining Quercus suber L. stand.

    Science.gov (United States)

    Lancellotti, Enrico; Franceschini, Antonio

    2013-10-01

    This survey was carried out in a Quercus suber L. stand with many trees affected by the disease "oak decline". Its aim was to obtain information about both the belowground ectomycorrhizal fungal community in a declining Q. suber stand as a whole, and the ectomycorrhizal fungal community of individual tree (EFT) detected in healthy and diseased plants. To this end, we first categorized the trees into four different decline classes (one for healthy plants and three for diseased plants) and then, by using morphological and molecular tools, we identified the ectomycorrhizas isolated from samples collected near the trees with different declining classes. The ectomycorrhizal community as a whole was seen to be composed of numerous ectomycorrhizal fungal species, only some of which appeared to be dominant (Cenococcum geophilum, Lactarius chrysorrheus, and some species of Tomentella genus), while most occurred sporadically. Results show that all root tips observed are mycorrhized and that decline class does not influence the number of ectomycorrhizal root tips found in the EFTs, thus oak decline does not impact the investment in ectomycorrhizal symbiosis. However, some statistical differences can be observed in the values of evenness and taxonomic distinctness in the EFT associated with trees with different states of health. Finally, both the analysis of similarity test and the ordination technique highlight a compositional difference between the EFT associated with trees in different health conditions, but also suggest that other factors may play a role in causing these differences.

  10. Cryopreservation of Quercus suber somatic embryos by encapsulation-dehydration and evaluation of genetic stability.

    Science.gov (United States)

    Fernandes, Pedro; Rodriguez, Eleazar; Pinto, Glória; Roldán-Ruiz, Isabel; De Loose, Marc; Santos, Conceição

    2008-12-01

    We describe an encapsulation and dehydration procedure for the cryopreservation of cork oak (Quercus suber L.) somatic embryos that resulted in at least 90% survival. Genetic stability of the regenerated material was assessed by flow cytometry (FCM), amplified fragment length polymorphisms (AFLP) and simple sequence repeats (SSR). Cryopreservation of embryogenic clusters involved encapsulation of each cluster in an alginate bead, followed by a 3-day culture in 0.7 M sucrose and subsequent desiccation to 25 or 35% water content (WC), followed by freezing in liquid nitrogen. Thawed, cryopreserved somatic embryos had high viability and exhibited long-term survival. No morphological differences were observed between somatic embryos desiccated to 25 and 35% WC. Analysis of DNA ploidy stability of control (i.e., encapsulated and dehydrated but not frozen) and cryopreserved material by flow cytometry showed no significant differences. Similarly, DNA-marker analyses (AFLPs and SSR) revealed no significant differences between control and cryopreserved samples at the DNA-sequence level. Nonetheless, because polymorphisms were found between control material and samples cryopreserved and desiccated to 25% WC, the 35% WC method is recommended for cryopreservation of this tissue type. Cryopreservation of Q. suber somatic embryos by this encapsulation-dehydration procedure has potential for use in long-term conservation programs.

  11. Differential DNA Methylation Patterns Are Related to Phellogen Origin and Quality of Quercus suber Cork

    Science.gov (United States)

    Costa, Augusta; Roussado, Cristóvão; Gonçalves, Elsa; Costa, Rita; Graça, José; Oliveira, M. Margarida

    2017-01-01

    DNA methylation is thought to influence Quercus suber cork quality, which is the main constraint for its economic valorisation. However, a deep knowledge of the cytosine methylation patterns disclosing the epigenetic variability of trees with different cork quality types is totally missing. This study investigates the hypothesis that variations in DNA methylation contribute to differences in cork cellular characteristics directly related to original or traumatic phellogen activity. We used MSAPs (Methylation Sensitive Amplified Polymorphism) to assess DNA methylation patterns of cork and leaf tissues of Q. suber adult trees growing in three cork oak stands. The relationship between the detected polymorphisms and the diversity of cork quality traits was explored by a marker-trait analysis focusing on the most relevant quality characteristics. Populations differed widely in cork quality, but only slightly in degree of epigenetic differentiation. Four MSAP markers (1.3% of the total) were significantly associated with the most noteworthy quality traits: wood inclusions (nails) and porosity. This evidence supports the potential role of cytosine methylation in the modulation of differential phellogen activity either involved in localized cell death or in pore production, resulting in different cork qualities. Although, the underlying basis of the methylation polymorphism of loci affecting cork quality traits remain unclear, the disclosure of markers statistically associated with cork quality strengthens the potential role of DNA methylation in the regulation of these traits, namely at the phellogen level. PMID:28045988

  12. Differential DNA Methylation Patterns Are Related to Phellogen Origin and Quality of Quercus suber Cork.

    Science.gov (United States)

    Inácio, Vera; Barros, Pedro M; Costa, Augusta; Roussado, Cristóvão; Gonçalves, Elsa; Costa, Rita; Graça, José; Oliveira, M Margarida; Morais-Cecílio, Leonor

    2017-01-01

    DNA methylation is thought to influence Quercus suber cork quality, which is the main constraint for its economic valorisation. However, a deep knowledge of the cytosine methylation patterns disclosing the epigenetic variability of trees with different cork quality types is totally missing. This study investigates the hypothesis that variations in DNA methylation contribute to differences in cork cellular characteristics directly related to original or traumatic phellogen activity. We used MSAPs (Methylation Sensitive Amplified Polymorphism) to assess DNA methylation patterns of cork and leaf tissues of Q. suber adult trees growing in three cork oak stands. The relationship between the detected polymorphisms and the diversity of cork quality traits was explored by a marker-trait analysis focusing on the most relevant quality characteristics. Populations differed widely in cork quality, but only slightly in degree of epigenetic differentiation. Four MSAP markers (1.3% of the total) were significantly associated with the most noteworthy quality traits: wood inclusions (nails) and porosity. This evidence supports the potential role of cytosine methylation in the modulation of differential phellogen activity either involved in localized cell death or in pore production, resulting in different cork qualities. Although, the underlying basis of the methylation polymorphism of loci affecting cork quality traits remain unclear, the disclosure of markers statistically associated with cork quality strengthens the potential role of DNA methylation in the regulation of these traits, namely at the phellogen level.

  13. Comparison between ethanol and hexane for oil extraction from Quercus suber L. fruits

    Directory of Open Access Journals (Sweden)

    Abreu, José M.F.

    2003-12-01

    Full Text Available The aim of this study was to (i evaluate the feasibility of replacing n-hexane with ethanol for the extraction of oil from Quercus suber fruits and (ii optimize, at lab scale, sample preparation and extraction time for both solvents used (n-hexane vs. anhydrous ethanol. For both solvents, the effect of the conditioning process on extraction yield was evaluated. Therefore, a full factorial design was used as a function of four variables: dehulling (with vs. without husks, and thermal treatment of the crushed material (40ºC vs. 75ºC, at different times (5 min vs. 120 min and pressures (10 kPa vs. 100 kPa. Higher oil yields were obtained with n-hexane when dehulled fruits were conditioned under atmospheric pressure. Better yields were obtained with n-hexane, when dehulled material was treated at 75ºC for 90 min. Ethanol was not adequate for oil extraction from Quercus fruits, since other materials rather than oil were also extracted.El objetivo de este estudio fue (i evaluar la posibilidad de reemplazar el n-hexano por el etanol para la extracción del aceite de los frutos de Quercus suber y (ii optimizar, a escala de laboratorio, la preparación de la muestra y el tiempo de extracción para ambos solventes (n-hexano vs. etanol anhidro. Para ambos solventes, se ha evaluado el efecto del proceso de acondicionamiento en el rendimiento de la extracción. Para ello, se ha empleado un diseño factorial completo como función de cuatro variables: descascarillado (con vs sin cascarilla, y tratamiento térmico del material triturado (40ºC vs. 75ºC, a diferentes tiempos (5 min vs. 120 min y presiones (10 kPa vs. 100 kPa. Los rendimientos más elevados de extracción de aceite se obtuvieron con n-hexano cuando los frutos descascarillados se acondicionaron a presión atmosférica. Cuando el material descascarillado fue tratado a 75ºC por 90 min, se obtuvieron mejores rendimientos con n-hexano. El etanol demostró no ser adecuado para la

  14. Proteomic analysis from haploid and diploid embryos of Quercus suber L. identifies qualitative and quantitative differential expression patterns.

    Science.gov (United States)

    Gómez, Aranzazu; López, Juan Antonio; Pintos, Beatriz; Camafeita, Emilio; Bueno, Ma Angeles

    2009-09-01

    Quercus suber L. is a Mediterranean forest species with ecological, social and economic value. Clonal propagation of Q. suber elite trees has been successfully obtained from in vitro-derived somatic and gametic embryos. These clonal lines play a main role in breeding and genetic studies of Q. suber. To aid in unravelling diverse genetic and biological unknowns, a proteomic approach is proposed. The proteomic analysis of Q. suber somatic and gametic in vitro culture-derived embryos, based on DIGE and MALDI-MS, has produced for the first time proteomic data on this species. Seventeen differentially expressed proteins have been identified which display significantly altered levels between gametic and somatic embryos. These proteins are involved in a variety of cellular processes, most of which had been neither previously associated with embryo development nor identified in the genus Quercus. Some of these proteins are involved in stress and pollen development and others play a role in the metabolism of tannins and phenylpropanoids, which represent two of the major pathways for the synthesis of cork chemical components. Furthermore, the augmented expression levels found for specific proteins are probably related to the homozygous state of a doubled-haploid sample. Proteins involved in synthesis of cork components can be detected at such early stages of development, showing the potential of the method to be useful in searching for biomarkers related to cork quality.

  15. Early markers are present in both embryogenesis pathways from microspores and immature zygotic embryos in cork oak, Quercus suber L

    OpenAIRE

    2014-01-01

    Background: In Quercus suber, cork oak, a Mediterranean forest tree of economic and social interest, rapid production of isogenic lines and clonal propagation of elite genotypes have been achieved by developing in vitro embryogenesis from microspores and zygotic embryos respectively. Despite its high potential in tree breeding strategies, due to their recalcitrancy, the efficiency of embryogenesis in vitro systems in many woody species is still very low since factors responsible for embryogen...

  16. Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber

    Directory of Open Access Journals (Sweden)

    Margarida eRocheta

    2014-11-01

    Full Text Available Monoecious species provide a comprehensive system to study the developmental programs underlying the establishment of female and male organs in unisexual flowers. However, molecular resources for most monoecious non-model species are limited, hampering our ability to study the molecular mechanisms involved in flower development of these species. The objective of this study was to identify differentially expressed genes during the development of male and female flowers of the monoecious species Quercus suber, an economically important Mediterranean tree. Total RNA was extracted from different developmental stages of Q. suber flowers. Non-normalised cDNA libraries of male and female flowers were generated using 454 pyrosequencing technology producing a total of 962,172 high-quality reads with an average length of 264 nucleotides. The assembly of the reads resulted in 14,488 contigs for female libraries and 10,438 contigs for male libraries. Comparative analysis of the transcriptomes revealed genes differentially expressed in early and late stages of development of female and male flowers, some of which have been shown to be involved in pollen development, in ovule formation and in flower development of other species with a monoecious, dioecious or hermaphroditic sexual system. Moreover, we found differentially expressed genes that have not yet been characterised and others that have not been previously shown to be implicated in flower development. This transcriptomic analysis constitutes a major step towards the characterisation of the molecular mechanisms involved in flower development in a monoecious tree with a potential contribution towards the knowledge of conserved developmental mechanisms in other species.

  17. Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber.

    Science.gov (United States)

    Rocheta, Margarida; Sobral, Rómulo; Magalhães, Joana; Amorim, Maria I; Ribeiro, Teresa; Pinheiro, Miguel; Egas, Conceição; Morais-Cecílio, Leonor; Costa, Maria M R

    2014-01-01

    Monoecious species provide a comprehensive system to study the developmental programs underlying the establishment of female and male organs in unisexual flowers. However, molecular resources for most monoecious non-model species are limited, hampering our ability to study the molecular mechanisms involved in flower development of these species. The objective of this study was to identify differentially expressed genes during the development of male and female flowers of the monoecious species Quercus suber, an economically important Mediterranean tree. Total RNA was extracted from different developmental stages of Q. suber flowers. Non-normalized cDNA libraries of male and female flowers were generated using 454 pyrosequencing technology producing a total of 962,172 high-quality reads with an average length of 264 nucleotides. The assembly of the reads resulted in 14,488 contigs for female libraries and 10,438 contigs for male libraries. Comparative analysis of the transcriptomes revealed genes differentially expressed in early and late stages of development of female and male flowers, some of which have been shown to be involved in pollen development, in ovule formation and in flower development of other species with a monoecious, dioecious, or hermaphroditic sexual system. Moreover, we found differentially expressed genes that have not yet been characterized and others that have not been previously shown to be implicated in flower development. This transcriptomic analysis constitutes a major step toward the characterization of the molecular mechanisms involved in flower development in a monoecious tree with a potential contribution toward the knowledge of conserved developmental mechanisms in other species.

  18. Molecular characterization of Quercus suber MYB1, a transcription factor up-regulated in cork tissues.

    Science.gov (United States)

    Almeida, Tânia; Menéndez, Esther; Capote, Tiago; Ribeiro, Teresa; Santos, Conceição; Gonçalves, Sónia

    2013-01-15

    The molecular processes associated with cork development in Quercus suber L. are poorly understood. A previous molecular approach identified a list of genes potentially important for cork formation and differentiation, providing a new basis for further molecular studies. This report is the first molecular characterization of one of these candidate genes, QsMYB1, coding for an R2R3-MYB transcription factor. The R2R3-MYB gene sub-family has been described as being involved in the phenylpropanoid and lignin pathways, both involved in cork biosynthesis. The results showed that the expression of QsMYB1 is putatively mediated by an alternative splicing (AS) mechanism that originates two different transcripts (QsMYB1.1 and QsMYB1.2), differing only in the 5'-untranslated region, due to retention of the first intron in one of the variants. Moreover, within the retained intron, a simple sequence repeat (SSR) was identified. The upstream regulatory region of QsMYB1 was extended by a genome walking approach, which allowed the identification of the putative gene promoter region. The relative expression pattern of QsMYB1 transcripts determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) revealed that both transcripts were up-regulated in cork tissues; the detected expression was several times higher in newly formed cork harvested from trees producing virgin, second or reproduction cork when compared with wood. Moreover, the expression analysis of QsMYB1 in several Q. suber organs showed very low expression in young branches and roots, whereas in leaves, immature acorns or male flowers, no expression was detected. These preliminary results suggest that QsMYB1 may be related to secondary growth and, in particular, with the cork biosynthesis process with a possible alternative splicing mechanism associated with its regulatory function.

  19. Regulation of transpirational water loss in Quercus suber trees in a Mediterranean-type ecosystem.

    Science.gov (United States)

    Otieno, D O; Schmidt, M W T; Kurz-Besson, C; Lobo Do Vale, R; Pereira, J S; Tenhunen, J D

    2007-08-01

    Sap flux density in branches, leaf transpiration, stomatal conductance and leaf water potentials were measured in 16-year-old Quercus suber L. trees growing in a plantation in southern Portugal to understand how evergreen Mediterranean trees regulate water loss during summer drought. Leaf specific hydraulic conductance and leaf gas exchange were monitored during the progressive summer drought to establish how changes along the hydraulic pathway influence shoot responses. As soil water became limiting, leaf water potential, stomatal conductance and leaf transpiration declined significantly. Predawn leaf water potential reflected soil water potential measured at 1-m depth in the rhizospheres of most trees. The lowest predawn leaf water potential recorded during this period was -1.8 MPa. Mean maximum stomatal conductance declined from 300 to 50 mmol m(-2) s(-1), reducing transpiration from 6 to 2 mmol m(-2) s(-1). Changes in leaf gas exchange were attributed to reduced soil water availability, increased resistances along the hydraulic pathway and, hence, reduced leaf water supply. There was a strong coupling between changes in soil water content and stomatal conductance as well as between stomatal conductance and leaf specific hydraulic conductance. Despite significant seasonal differences among trees in predawn leaf water potential, stomatal conductance, leaf transpiration and leaf specific hydraulic conductance, there were no differences in midday leaf water potentials. The strong regulation of changes in leaf water potential in Q. suber both diurnally and seasonally is achieved through stomatal closure, which is sensitive to changes in both liquid and vapor phase conductance. This sensitivity allows for optimization of carbon and water resource use without compromising the root-shoot hydraulic link.

  20. Detection of hybrids in nature: application to oaks (Quercus suber and Q. ilex).

    Science.gov (United States)

    Burgarella, C; Lorenzo, Z; Jabbour-Zahab, R; Lumaret, R; Guichoux, E; Petit, R J; Soto, A; Gil, L

    2009-05-01

    Powerful and accurate detection of first-generation (F1) hybrids and backcrosses in nature is needed to achieve a better understanding of the function and dynamics of introgression. To document the frequency of ongoing interspecific gene exchange between two Mediterranean evergreen oaks, the cork oak (Quercus suber) and the holm oak (Q. ilex), we analyzed 1487 individuals originating from across the range of the two species using eight microsatellite loci and two Bayesian clustering approaches (implemented in the programs STRUCTURE and NEWHYBRIDS). Simulated data were used to assess the differences between the two clustering methods and to back up the choice of the threshold value for the posterior probability to discriminate admixed from pure individuals. We found that the use of STRUCTURE resulted in the highest power to detect hybrids, whereas NEWHYBRIDS provided the highest accuracy. Irrespective of the approach, the two species were clearly distinguished as independent genetic entities without any prior information. In contrast with previous reports, we found no evidence for unidirectional introgression. The overall hybridization rate was very low (<2% of introgressed individuals). Only two individuals were identified as F1 hybrids and five as early backcrosses. This work shows that the combined application of the two complementary Bayesian approaches and their systematic validation with simulations, fit for the case at hand, helps gain resolution in the identification of admixed individuals.

  1. Assessment of ploidy stability of the somatic embryogenesis process in Quercus suber L. using flow cytometry.

    Science.gov (United States)

    Loureiro, J; Pinto, G; Lopes, T; Dolezel, J; Santos, C

    2005-08-01

    Flow cytometry analyses were used to verify the ploidy stability of Quercus suber L. somatic embryogenesis process. Leaf explants of two adult cork oak trees (QsG0 and QsG5) of the North of Portugal were inoculated on MS medium with 2,4-D and zeatin. After 3 months, calluses with embryogenic structures were isolated and transferred to fresh MS medium without growth regulators and somatic embryo evolution was followed. Morphologically normal somatic embryos (with two cotyledons) and abnormal somatic embryos (with one or three cotyledons) were used in this assay. Flow cytometry combined with propidium iodide staining was employed to estimate DNA ploidy levels and nuclear DNA content of somatic embryos and leaves from mother plants. No significant differences (P< or =0.05) were detected among embryos, and between the embryos and the mother plants. Also, after conversion of these embryos, no significant morphological differences were observed among the somatic embryo-derived plants. These results and further studies using converted plantlet leaves and embryogenic callus tissue indicate that embryo cultures and converted plantlets were stable with regard to ploidy level. As no major somaclonal variation was detected our primary goal of "true-to-type" propagation of cork oak using somatic embryogenesis was assured at this level. The estimation of the 2C nuclear DNA content for this species is similar to the previously obtained value.

  2. Recurrent fires and environment shape the vegetation in Quercus suber L. woodlands and maquis.

    Science.gov (United States)

    Schaffhauser, Alice; Curt, Thomas; Véla, Errol; Tatoni, Thierry

    2012-06-01

    The effects of fire recurrence on vegetation patterns in Quercus suber L. and Erica-Cistus communities in Mediterranean fire-prone ecosystems of south-eastern France were examined on stands belonging to 5 fire classes, corresponding to different numbers of fires (from 0 to 4) and time intervals between fires since 1959. A common pool of species was identified among the plots, which was typical of both open and closed maquis. Fire recurrence reduced the abundance of trees and herbs, whereas it increased the abundance of small shrubs. Richness differed significantly between the most contrasting classes of fire recurrence, with maximal values found in control plots and minimal values in plots that had burned recurrently and recently. Equitability indices did not vary significantly, in contrast to Shannon's diversity index which mostly correlated with richness. Forest ecosystems that have burnt once or twice in the last 50 years were resilient; that is to say they recovered a biomass and composition similar to that of the pre-fire state. However, after more than 3-4 fires, shrubland communities displayed lower species richness and diversity indices than unburned plots. The time since the last fire and the number of fires were the most explanatory fire variables, governing the structure of post-fire plant communities. However, environmental factors, such as slope or exposure, also made a significant contribution. Higher rates of fire recurrence can affect the persistence or expansion of shrublands in the future, as observed in other Mediterranean areas.

  3. Proteins associated with cork formation in Quercus suber L. stem tissues.

    Science.gov (United States)

    Ricardo, Cândido P P; Martins, Isabel; Francisco, Rita; Sergeant, Kjell; Pinheiro, Carla; Campos, Alexandre; Renaut, Jenny; Fevereiro, Pedro

    2011-08-12

    Cork (phellem) formation in Quercus suber stem was studied by proteomic analysis of young shoots of increasing age (Y0, Y1 and Y4) and recently-formed phellem (Y8Ph) and xylem (Y8X) from an 8-year-old branch. In this study 99 proteins were identified, 45 excised from Y8X and 54 from Y8Ph. These ones, specifically associated with phellem, are of "carbohydrate metabolism" (28%), "defence" (22%), "protein folding, stability and degradation" (19%), "regulation/signalling" (11%), "secondary metabolism" (9%), "energy metabolism" (6%), and "membrane transport" (2%). The identification in phellem of galactosidases, xylosidases, apiose/xylose synthase, laccases and diphenol oxidases suggests intense cell wall reorganization, possibly with participation of hemicellulose/pectin biosynthesis and phenol oxidation. The identification of proteasome subunits, heat shock proteins, cyclophylin, subtilisin-like proteases, 14-3-3 proteins, Rab2 protein and enzymes interacting with nucleosides/nucleic acids gives additional evidence for cellular reorganization, involving cellular secretion, protein turnover regulation and active control processes. The high involvement in phellem of defence proteins (thioredoxin-dependent peroxidase, glutathione-S-transferase, SGT1 protein, cystatin, and chitinases) suggests a strong need for cell protection from the intense stressful events occurring in active phellem, namely, desiccation, pests/disease protection, detoxification and cell death. Identically, highly enhanced defence functions were previously reported for potato periderm formation.

  4. Demonstration of pectic polysaccharides in cork cell wall from Quercus suber L.

    Science.gov (United States)

    Rocha, S M; Coimbra, M A; Delgadillo, I

    2000-06-01

    Scanning electron microscopy (SEM) and chemical analysis were used to observe the cell wall changes that occur in cork with "mancha amarela", when compared to a standard cork. To mimic the microbial attack exhibited in cork with mancha amarela, the standard cork was treated enzymatically with commercial pectinase and hemicellulase preparations. The tissues treated with pectinase were comparable with those attacked with mancha amarela. Both were composed by deformed and wrinkly cells and exhibited cell wall separation at the middle lamella level, which suggests solubilization/removal of the pectic polysaccharides. The cork cell wall material, prepared as alcohol-insoluble residue, was fractionated by hot water (Pect(H)()2(O)) and hot dilute acid (Pect(acid)). The relatively large amount of hexuronic acid and the occurrence of Ara in the SPect(H)()2(O) and SPect(acid) allow to confirm, as far as we know, for the first time the presence of pectic polysaccharides in the cell walls of cork from Quercus suber L. They accounted for ca. 1.5% of the cork and may consist of polymers with long side chains of arabinosyl residues. These polymers have to be taken into account in any realistic model of the cork cell wall. Cork with mancha amarela contained a smaller amount of pectic polysaccharides (ca. 0.5%), which confirms that the cellular separation observed by SEM is related to the degradation/removal of the middle lamella pectic polysaccharides.

  5. Composition of suberin extracted upon gradual alkaline methanolysis of Quercus suber L. cork.

    Science.gov (United States)

    Lopes, M H; Gil, A M; Silvestre, A J; Neto, C P

    2000-02-01

    The monomeric composition of suberin extracts obtained by gradual alkaline methanolysis of Quercus suber cork was determined by gas chromatography-mass spectrometry (GC-MS). Results show that 1-alkanols and alkanoic and alpha,omega-alkanedioic acids are preferentially removed upon mild alkaline conditions, whereas mid-chain-modified omega-hydroxyalkanoic acids are preferentially removed under stronger alkaline conditions. Saturated omega-hydroxyalkanoic acids are found to be abundant in all suberin extracts. These results are consistent with two distinct suberin fractions with different locations in cork cell walls and/or esterification degrees. It is proposed that these fractions correlate with the two main suberin peaks in the solid state (13)C NMR spectra of cork and suberin extracts. Quantitative GC-MS analysis showed that suberin monomers comprise approximately 30% (w/w) of the suberin extracts, the remaining comprising nonvolatile structures with high M(n) values, as measured by vapor pressure osmometry. The presence of a large fraction of high molecular weight aliphatic structures in suberin extracts is supported by the corresponding NMR spectra.

  6. Corky, a gypsy-like retrotransposon is differentially transcribed in Quercus suber tissues

    Directory of Open Access Journals (Sweden)

    Rocheta Margarida

    2012-08-01

    Full Text Available Abstract Background Transposable elements (TEs make up a large part of eukaryotic genomes. Due to their repetitive nature and to the fact that they harbour regulatory signals, TEs can be responsible for chromosomal rearrangements, movement of gene sequences and evolution of gene regulation and function. Retrotransposon ubiquity raises the question about their function in genomes and most are transcriptionally inactive due to rearrangements that compromise their activity. However, the activity of TEs is currently considered to have been one of the major processes in genome evolution. Findings We report on the characterization of a transcriptionally active gypsy-like retrotransposon (named Corky from Quercus suber, in a comparative and quantitative study of expression levels in different tissues and distinct developmental stages through RT-qPCR. We observed Corky’s differential transcription levels in all the tissues analysed. Conclusions These results document that Corky’s transcription levels are not constant. Nevertheless, they depend upon the developmental stage, the tissue analysed and the potential occurring events during an individuals’ life span. This modulation brought upon by different developmental and environmental influences suggests an involvement of Corky in stress response and during development.

  7. Antioxidant and biological properties of bioactive phenolic compounds from Quercus suber L.

    Science.gov (United States)

    Fernandes, Ana; Fernandes, Iva; Cruz, Luís; Mateus, Nuno; Cabral, Miguel; de Freitas, Victor

    2009-12-09

    Phenolic compounds, namely, hydrolyzable tannins and low molecular weight phenolic compounds, were isolated and purified from Portuguese cork from Quercus suber L. Some of these compounds were studied to evaluate their antioxidant activity, including free-radical scavenging capacity (DPPH method) and reducing capacity (FRAP method). All compounds tested showed significant antioxidant activity, namely, antiradical and reducing properties. The antiradical capacity seemed to increase with the presence of galloyl groups. Regarding the reducing capacity, this structure-activity relationship was not so clear. These compounds were also studied to evaluate the growth inhibitory effect on the estrogen responsive human breast cancer cell line (ER+) MCF-7 and two other colon cancer cell lines (Caco-2 and HT-29). Generally, all the compounds tested exhibited, after a continuous exposure during a 48 h period, a dose-dependent growth inhibitory effect. Relative inhibitory activity was primarily related to the number of phenolic hydroxyl groups (galloyl and HHDP moieties) found in the active structures, with more groups generally conferring increased effects, except for HHDP-di-galloyl-glucose. Mongolicain B showed a greater potential to inhibit the growth of the three cell lines tested, identical to the effect observed with castalagin. Since these compounds are structurally related with each other, this activity might be based within the C-glycosidic ellagitannin moiety.

  8. Histology of Organogenic and Embryogenic Responses in Cotyledons of Somatic Embryos of Quercus Suber L.

    Science.gov (United States)

    Puigderrajols; Celestino; Suils; Toribio; Molinas

    2000-05-01

    In cork oak (Quercus suber L.), recurrent embryogenesis is produced in vitro through autoembryony without exogenous plant growth regulators (PGRs); secondary embryos appear on the embryo axis but seldom on cotyledons. Focusing mainly on the histological origin of neoformations, we investigated the influence of the embryo axis and exogenous PGRs on the embryogenic potential of somatic embryo cotyledons. Isolated cotyledons of somatic embryos became necrotic when cultured on PGR-free medium but gave secondary embryos when cultured on media containing benzyladenine and naphthaleneacetic acid. Cotyledons of cork oak somatic embryos are competent to give embryogenic responses. Isolated cotyledons without a petiole showed a lower percentage of embryogenic response than did those with a petiole. In petioles, somatic embryos arose from inner parenchyma tissues following a multicellular budding pattern. Joined to the embryo axis, cotyledons did not show morphogenic responses when cultured on PGR-free medium but revealed budlike and phylloid formations when cultured on medium with PGRs. The different morphogenic behavior displayed by somatic cotyledons indicates an influence of the embryo axis and indicates a relationship between organogenic and embryogenic regeneration pathways.

  9. Cryopreservation of embryogenic cultures from mature Quercus suber trees using vitrification.

    Science.gov (United States)

    Valladares, Silvia; Toribio, Mariano; Celestino, Cristina; Vieitez, Ana M

    2004-01-01

    Recent progress in somatic embryogenesis from selected mature trees of Quercus suber, has led to a demand for maintenance of a large number of selected embryogenic lines. To facilitate the management of this material a protocol for the long-term storage of this germplasm should be defined. This study reports on the use of a simple vitrification procedure for the successful cryopreservation of three cork oak embryogenic lines. High embryo recovery levels (88-93 percent) were obtained by first preculturing 2-4 mg clumps of two or three globular embryos on semisolid medium containing 0.3 M sucrose for three days, followed by incubation in PVS2 vitrification solution at 0 degree C for 60 min before direct immersion in liquid nitrogen. The mean number of embryos produced per explant was significantly greater for cryostored embryos than for untreated stock cultures, but the productivity of the latter was recovered in subsequent subcultures of the material produced by cryostored embryos. The germination and plant regeneration rates achieved by cultures derived from cryostored embryos, around 60 percent, were similar to those of non-cryopreserved stock cultures.

  10. Enzymatic isolation and structural characterisation of polymeric suberin of cork from Quercus suber L.

    Science.gov (United States)

    Rocha, S M; Goodfellow, B J; Delgadillo, I; Neto, C P; Gil, A M

    2001-01-10

    An enzymatic method has been used to isolate, for the first time, polymeric suberin from the bark of Quercus suber L. or cork. This was achieved by solvent extraction (dichloromethane, ethanol and water), followed by a step-by-step enzymatic treatment with cellulase, hemicellulase and pectinase, and a final extraction with dioxane/water. The progress of suberin isolation was monitored by Fourier transform infrared spectroscopy using a photoacoustic cell (FTIR-PAS). The material obtained (polymeric suberin (PS)) was characterised by solid-state and liquid-state nuclear magnetic resonance, FTIR-PAS and vapour pressure osmometry, and compared with the suberin fraction obtained by alkaline depolymerisation (depolymerised suberin (DS)). The results showed that PS is an aliphatic polyester of saturated and unsaturated fatty acids, with an average molecular weight (M(w)) of 2050 g mol(-1). Although this fraction represents only 10% of the whole suberin of cork, its polymeric nature gives valuable information about the native form of the polymer. DS was found to have an average M(w) of 750 g mol(-1) and to comprise a significant amount of acidic and alcoholic short aliphatic chains.

  11. Epigenetic and hormonal profile during maturation of Quercus Suber L. somatic embryos.

    Science.gov (United States)

    Pérez, Marta; Viejo, Marcos; LaCuesta, Maite; Toorop, Peter; Cañal, María Jesús

    2015-01-15

    Somatic embryogenesis is a powerful alternative to conventional mass propagation of Quercus suber L. However, poor quality and incomplete maturation of somatic embryos restrict any application. Given that epigenetic and hormonal control govern many developmental stages, including maturation of zygotic embryos, global DNA methylation and abscisic acid (ABA) were analyzed during development and maturation of cork oak somatic embryos. Our results indicated that development of somatic embryos concurred with a decrease in 5-mdC. In contrast, endogenous ABA content showed a transient increase with a peak in immature E2 embryos denoting the onset of the maturation phase. A cold stratification phase was necessary for embryos to acquire germination ability, which coincided with a significant decrease in 5-mdC and ABA content. Immunohistochemical analyses showed that there was a specific spatial-temporal regulation during embryogenesis, particularly after the cold treatment. The acquisition of germination capacity concurred with a general low 5-mdC signal in the root meristem, while retention of the 5-mdC signal was mainly located in the shoot meristem and provascular tissues. Conversely, ABA immunolocalization was mainly located in the root and shoot apical meristems. Furthermore, a strong decrease in the ABA signal was observed in the root cap after the stratification treatment suggesting a role for the root cap during development of somatic embryos. These results suggest that, in addition to ABA, epigenetic control appears to play an important role for the correct maturation and subsequent germination of cork oak somatic embryos.

  12. Diurnal changes in photoprotective mechanisms in leaves of cork oak (Quercus suber) during summer.

    Science.gov (United States)

    Faria, T.; García-Plazaola, J. I.; Abadía, A.; Cerasoli, S.; Pereira, J. S.; Chaves, M. M.

    1996-01-01

    Daily variations in photoprotective mechanisms were studied in sun and shade leaves of 40-year-old cork oak (Quercus suber L.) trees during early summer in Portugal. Although trees were not severely water stressed because predawn leaf water potentials remained high, photosynthesis and stomatal conductance decreased at midday. The midday depression in gas exchange was not reversed by short-term exposure to "optimal" conditions of temperature, light and vapor pressure deficit. Chlorophyll a fluorescence, maximum photochemical yield of photosystem II and the quantum yield of noncyclic electron transport showed midday depressions, but recovered by the evening. Both short-term changes in the components of the xanthophyll cycle (reversible de-epoxidation of violaxanthin during the day) as well as long-term changes (higher xanthophyll content in sun compared with shade leaves) were detected and may play a role in the dissipation of excess energy at midday. Because the activities of enzymes of the antioxidant system, superoxide dismutase and ascorbate peroxidase, were high enough to cope with the increase in oxygen reactive species likely to arise under the stressful conditions of midday, we conclude that these enzymes may provide an additional mechanism for energy dissipation.

  13. The distribution of Quercus suber chloroplast haplotypes matches the palaeogeographical history of the western Mediterranean.

    Science.gov (United States)

    Magri, D; Fineschi, S; Bellarosa, R; Buonamici, A; Sebastiani, F; Schirone, B; Simeone, M C; Vendramin, G G

    2007-12-01

    Combining molecular analyses with geological and palaeontological data may reveal timing and modes for the divergence of lineages within species. The Mediterranean Basin is particularly appropriate for this kind of multidisciplinary studies, because of its complex geological history and biological diversity. Here, we investigated chloroplast DNA of Quercus suber populations in order to detect possible relationships between their geographical distribution and the palaeogeographical history of the western Mediterranean domain. We analysed 110 cork oak populations, covering the whole distribution range of the species, by 14 chloroplast microsatellite markers, among which eight displayed variation among populations. We identified five haplotypes whose distribution is clearly geographically structured. Results demonstrated that cork oak populations have undergone a genetic drift geographically consistent with the Oligocene and Miocene break-up events of the European-Iberian continental margin and suggested that they have persisted in a number of separate microplates, currently found in Tunisia, Sardinia, Corsica, and Provence, without detectable chloroplast DNA modifications for a time span of over 15 million years. A similar distribution pattern of mitochondrial DNA of Pinus pinaster supports the hypothesis of such long-term persistence, in spite of Quaternary climate oscillations and of isolation due to insularity, and suggests that part of the modern geographical structure of Mediterranean populations may be traced back to the Tertiary history of taxa.

  14. Characterization of the responses of cork oak (Quercus suber) to iron deficiency.

    Science.gov (United States)

    Gogorcena, Y; Molias, N; Larbi, A; Abadía, J; Abadía, A

    2001-12-01

    We studied responses of cork oak (Quercus suber L.) to iron (Fe) deficiency by comparing seedlings grown hydroponically in nutrient solution with and without Fe. Seedlings grown without Fe developed some responses typical of the Strategy I group of Fe-efficient plants, including two- and fourfold increases in plasma membrane ferric chelate reductase activity of root tips after 2 and 4 weeks of culture in the absence of Fe, respectively. Moreover, seedlings grown hydroponically for 2 weeks without Fe caused marked decreases in the pH of the nutrient solution, indicating that root plasma membrane ATPase activity was induced by Fe deficiency. Iron deficiency also caused marked decreases in leaf chlorophyll and carotenoid concentrations, and chlorophyll concentrations were decreased more than carotenoid concentrations. Iron deficiency resulted in an 8% decrease in the dark-adapted efficiency of photosystem II and a 43% decrease in efficiency of photosystem II at steady-state photosynthesis. No major root morphological changes were observed in seedlings grown without Fe, although seedlings grown in Fe-deficient nutrient solution had light-colored roots in contrast to the dark brown color of control roots.

  15. Lignin Composition and Structure Differs between Xylem, Phloem and Phellem in Quercus suber L.

    Science.gov (United States)

    Lourenço, Ana; Rencoret, Jorge; Chemetova, Catarina; Gominho, Jorge; Gutiérrez, Ana; del Río, José C.; Pereira, Helena

    2016-01-01

    The composition and structure of lignin in different tissues—phellem (cork), phloem and xylem (wood)—of Quercus suber was studied. Whole cell walls and their respective isolated milled lignins were analyzed by pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS), two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) and derivatization followed by reductive cleavage (DFRC). Different tissues presented varied p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) lignin compositions. Whereas lignin from cork has a G-rich lignin (H:G:S molar ratio 2:85:13), lignin from phloem presents more S-units (H:G:S molar ratio of 1:58:41) and lignin from xylem is slightly enriched in S-lignin (H:G:S molar ratio 1:45:55). These differences were reflected in the relative abundances of the different interunit linkages. Alkyl-aryl ethers (β–O–4′) were predominant, increasing from 68% in cork, to 71% in phloem and 77% in xylem, as consequence of the enrichment in S-lignin units. Cork lignin was enriched in condensed structures such as phenylcoumarans (β-5′, 20%), dibenzodioxocins (5–5′, 5%), as corresponds to a lignin enriched in G-units. In comparison, lignin from phloem and xylem presented lower levels of condensed linkages. The lignin from cork was highly acetylated at the γ-OH of the side-chain (48% lignin acetylation), predominantly over G-units; while the lignins from phloem and xylem were barely acetylated and this occurred mainly over S-units. These results are a first time overview of the lignin structure in xylem, phloem (generated by cambium), and in cork (generated by phellogen), in agreement with literature that reports that lignin biosynthesis is flexible and cell specific. PMID:27833631

  16. Carbon storage in degraded cork oak (Quercus suber forests on flat lowlands in Morocco

    Directory of Open Access Journals (Sweden)

    Oubrahim H

    2016-02-01

    Full Text Available The present study aims to quantify the carbon stored in a degraded cork oak (Quercus suber L. ecosystem in the north west of Morocco, in view of potential management implications. To this end, carbon stocks were evaluated in the first 100 cm of the soil, the cork oak trees, and the understorey species (both above- and belowground. Results show that the total carbon stocks in the cork oak ecosystem ranges from 65 to 237 Mg ha-1 with a mean value of 121 Mg ha-1. The first 100 cm of the soil (including the forest floor represents the largest carbon pool (~51% of the total organic carbon of the ecosystem. Tree biomass (above- and belowground tissues of cork oak represents the second largest pool (47%, whereas the contribution of the understorey is less than 2%. Within the first 100 cm of the soil, over 87% of all the soil organic carbon is situated in the first 40 cm of the soil depth. The amount of carbon stored here ranges from 30 to 110 Mg ha-1and these organic carbon stocks vary considerably with the stand basal area of the cork oak (R2 = 0.82. In practice, the carbon stocks of the different pools considered are strongly correlated with the stand density of the cork oak stands. In the semi-arid forest ecosystems of our study, management prescriptions aiming at increasing the standing biomass of the cork oak should thus considerably contribute, both directly through tree biomass and indirectly through increased soil organic matter, to efficient carbon sequestration.

  17. Effects of cadmium on cork oak (Quercus suber L.) plants grown in hydroponics.

    Science.gov (United States)

    Gogorcena, Yolanda; Larbi, Ajmi; Andaluz, Sofia; Carpena, Ramón O; Abadía, Anunciación; Abadía, Javier

    2011-12-01

    Cork oak (Quercus suber L.) is an autochthonous tree species that is being used for reforestation in heavy-metal-contaminated areas in Spain. A hydroponics experiment was carried out to characterize the effects of Cd on several morphological and physiological parameters in this species, including shoot length, nutrient concentrations and allocation in different organs, leaf pigment concentrations, photosynthetic efficiency, root ferric chelate reductase (FCR) activity and organic acid concentrations in xylem sap. Four different Cd treatments were applied, adding Cd chelated with EDTA or as chloride salt at two different concentrations (10 and 50 µM Cd). After 1 month of Cd treatment, plant growth was significantly inhibited in all treatments. Results indicate that Cd accumulates in all organs 7- to 500-fold when compared with control plants. The highest Cd concentration was found in the 50 µM CdCl(2) treatment, which led to concentrations of ~30, 123 and 1153 µg Cd g(-1) dry weight in leaves, stems and roots, respectively. In the strongest Cd treatments the concentrations of P and Ca decreased in some plant parts, whereas the Mn leaf concentrations decreased with three of the four Cd treatments applied. The concentrations of chlorophyll and carotenoids on an area basis decreased, whereas the (zeaxanthin plus antheraxanthin)/(total violaxanthin cycle carotenoids) ratio and the non-photochemical quenching increased significantly in all Cd treatments. Cadmium treatments caused significant increases in the activity of the enzyme FCR in roots and in the concentrations of organic acids in xylem sap. Some of the physiological changes found support the fact that Cd induces a deficiency of Fe in cork oak, although the plant Fe concentrations were not reduced significantly. At higher concentrations the effects of Cd were more pronounced, and were more marked when Cd was in the free ion form than when present in the form of Cd-EDTA.

  18. Lignin Composition and Structure Differs between Xylem, Phloem and Phellem in Quercus suber L.

    Science.gov (United States)

    Lourenço, Ana; Rencoret, Jorge; Chemetova, Catarina; Gominho, Jorge; Gutiérrez, Ana; Del Río, José C; Pereira, Helena

    2016-01-01

    The composition and structure of lignin in different tissues-phellem (cork), phloem and xylem (wood)-of Quercus suber was studied. Whole cell walls and their respective isolated milled lignins were analyzed by pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS), two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) and derivatization followed by reductive cleavage (DFRC). Different tissues presented varied p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) lignin compositions. Whereas lignin from cork has a G-rich lignin (H:G:S molar ratio 2:85:13), lignin from phloem presents more S-units (H:G:S molar ratio of 1:58:41) and lignin from xylem is slightly enriched in S-lignin (H:G:S molar ratio 1:45:55). These differences were reflected in the relative abundances of the different interunit linkages. Alkyl-aryl ethers (β-O-4') were predominant, increasing from 68% in cork, to 71% in phloem and 77% in xylem, as consequence of the enrichment in S-lignin units. Cork lignin was enriched in condensed structures such as phenylcoumarans (β-5', 20%), dibenzodioxocins (5-5', 5%), as corresponds to a lignin enriched in G-units. In comparison, lignin from phloem and xylem presented lower levels of condensed linkages. The lignin from cork was highly acetylated at the γ-OH of the side-chain (48% lignin acetylation), predominantly over G-units; while the lignins from phloem and xylem were barely acetylated and this occurred mainly over S-units. These results are a first time overview of the lignin structure in xylem, phloem (generated by cambium), and in cork (generated by phellogen), in agreement with literature that reports that lignin biosynthesis is flexible and cell specific.

  19. Lignin composition and structure differs between xylem, phloem and phellem in Quercus suber L.

    Directory of Open Access Journals (Sweden)

    Ana Lourenço

    2016-10-01

    Full Text Available The composition and structure of lignin in different tissues - phellem (cork, phloem and xylem (wood - of Quercus suber was studied. Whole cell walls and their respective isolated milled lignins were analyzed by pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS, two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR and derivatization followed by reductive cleavage (DFRC. Different tissues presented varied p-hydroxyphenyl:guaiacyl:syringyl (H:G:S lignin compositions. Whereas lignin from cork has a G-rich lignin (H:G:S molar ratio 2:85:13, lignin from phloem presents more S-units (H:G:S molar ratio of 1:58:41 and lignin from xylem is slightly enriched in S-lignin (H:G:S molar ratio 1:45:55. These differences were reflected in the relative abundances of the different interunit linkages. Alkyl-aryl ethers (β–O–4´ were predominant, increasing from 68% in cork, to 71% in phloem and 77% in xylem, as consequence of the enrichment in S-lignin units. Cork lignin was enriched in condensed structures such as phenylcoumarans (β-5´, 20%, dibenzodioxocins (5-5´, 5%, as corresponds to a lignin enriched in G-units. In comparison, lignin from phloem and xylem presented lower levels of condensed linkages. The lignin from cork was highly acetylated at the γ-OH of the side-chain (48% lignin acetylation, predominantly over G-units; while the lignins from phloem and xylem were barely acetylated and this occurred mainly over S-units. These results are a first time overview of the lignin structure in xylem, phloem (generated by cambium, and in cork (generated by phellogen, in agreement with literature that lignin biosynthesis is flexible and cell specific.

  20. Quercus suber range dynamics by ecological niche modelling: from the Last Interglacial to present time

    Science.gov (United States)

    Vessella, Federico; Simeone, Marco Cosimo; Schirone, Bartolomeo

    2015-07-01

    Ecological Niche Modelling (ENM) is widely used to depict species potential occurrence according to environmental variables under different climatic scenarios. We tested the ENM approach to infer past range dynamics of cork oak, a keystone species of the Mediterranean Biome, from 130 ka to the present time. Hindcasting implications would deal with a better species risk assessment and conservation management for the future. We modelled present and past occurrence of cork oak using seven ENM algorithms, starting from 63,733 spatially unique presence points at 30 arc-second resolution. Fourteen environmental variables were used and four time slices were considered (Last Interglacial, Last Glacial Maximum, mid-Holocene and present time). A threshold-independent evaluation of the goodness-of-fit of the models was evaluated by means of ROC curve and fossil or historical evidences were used to validate the results. Four weighted average maps depicted the dynamics of area suitability for cork oak in the last 130 ka. The derived species autoecology allowed its long-term occurrence in the Mediterranean without striking range reduction or shifting. Fossil and historical post-processing validation support the modelled past spatial extension and a neglected species presence at Levantine until the recent time. Despite the severe climatic oscillation since the Last Glacial Maximum, cork oak potential distribution area experienced limited range changes, confirming its strong link with the Mediterranean Basin. The ecological amplitude of Quercus suber could be therefore adopted as a reference to trace the Mediterranean bioclimate area. A better knowledge of the past events of Mediterranean vegetation, a wider range of study species and environmental determinants are essential to inform us about its current state, its sensitivity to human impact and the potential responses to future changes.

  1. Reference gene selection for quantitative real-time PCR normalization in Quercus suber.

    Science.gov (United States)

    Marum, Liliana; Miguel, Andreia; Ricardo, Cândido P; Miguel, Célia

    2012-01-01

    The use of reverse transcription quantitative PCR technology to assess gene expression levels requires an accurate normalization of data in order to avoid misinterpretation of experimental results and erroneous analyses. Despite being the focus of several transcriptomics projects, oaks, and particularly cork oak (Quercus suber), have not been investigated regarding the identification of reference genes suitable for the normalization of real-time quantitative PCR data. In this study, ten candidate reference genes (Act, CACs, EF-1α, GAPDH, His3, PsaH, Sand, PP2A, ß-Tub and Ubq) were evaluated to determine the most stable internal reference for quantitative PCR normalization in cork oak. The transcript abundance of these genes was analysed in several tissues of cork oak, including leaves, reproduction cork, and periderm from branches at different developmental stages (1-, 2-, and 3-year old) or collected in different dates (active growth period versus dormancy). The three statistical methods (geNorm, NormFinder, and CV method) used in the evaluation of the most suitable combination of reference genes identified Act and CACs as the most stable candidates when all the samples were analysed together, while ß-Tub and PsaH showed the lowest expression stability. However, when different tissues, developmental stages, and collection dates were analysed separately, the reference genes exhibited some variation in their expression levels. In this study, and for the first time, we have identified and validated reference genes in cork oak that can be used for quantification of target gene expression in different tissues and experimental conditions and will be useful as a starting point for gene expression studies in other oaks.

  2. Reference gene selection for quantitative real-time PCR normalization in Quercus suber.

    Directory of Open Access Journals (Sweden)

    Liliana Marum

    Full Text Available The use of reverse transcription quantitative PCR technology to assess gene expression levels requires an accurate normalization of data in order to avoid misinterpretation of experimental results and erroneous analyses. Despite being the focus of several transcriptomics projects, oaks, and particularly cork oak (Quercus suber, have not been investigated regarding the identification of reference genes suitable for the normalization of real-time quantitative PCR data. In this study, ten candidate reference genes (Act, CACs, EF-1α, GAPDH, His3, PsaH, Sand, PP2A, ß-Tub and Ubq were evaluated to determine the most stable internal reference for quantitative PCR normalization in cork oak. The transcript abundance of these genes was analysed in several tissues of cork oak, including leaves, reproduction cork, and periderm from branches at different developmental stages (1-, 2-, and 3-year old or collected in different dates (active growth period versus dormancy. The three statistical methods (geNorm, NormFinder, and CV method used in the evaluation of the most suitable combination of reference genes identified Act and CACs as the most stable candidates when all the samples were analysed together, while ß-Tub and PsaH showed the lowest expression stability. However, when different tissues, developmental stages, and collection dates were analysed separately, the reference genes exhibited some variation in their expression levels. In this study, and for the first time, we have identified and validated reference genes in cork oak that can be used for quantification of target gene expression in different tissues and experimental conditions and will be useful as a starting point for gene expression studies in other oaks.

  3. Removal of chromium (VI in aqueous environments using cork and heat-treated cork samples from Quercus cerris and Quercus suber

    Directory of Open Access Journals (Sweden)

    Ali Şen

    2012-11-01

    Full Text Available Chromium (VI removal and its reduction to chromium (III from aqueous solution by untreated and heat-treated Quercus cerris and heat-treated Quercus suber black agglomerate cork granules was investigated. Initial screening studies revealed that among the sorbents tested, untreated Q. cerris and Q. suber black agglomerate are the most efficient in the removal of Cr(VI ions and were selected for adsorption essays. Heat treatment adversely affected chromium adsorption and chromium (VI reduction in Q. cerris cork. The highest metal uptake was found at pH 3.0 for Q. cerris and pH 2.0 for black agglomerate. The experimental data fitted the Langmuir model and the calculated qmax was 22.98 mg/g in black agglomerate and 21.69 mg/g in untreated Q. cerris cork. The FTIR results indicated that while in black agglomerate, lignin is the sole component responsible for Cr(VI sorption, and in untreated Q. cerris cork, suberin and polysaccharides also play a significant role on the sorption. The SEM-EDX results imply that chromium has a homogenous distribution within both cork granules. Also, phloemic residues in Q. cerris granules showed higher chromium concentration. The results obtained in this study show that untreated Q. cerris and black agglomerate cork granules can be an effective and economical alternative to more costly materials for the treatment of liquid wastes containing chromium.

  4. Differential DNA Methylation Patterns Are Related to Phellogen Origin and Quality of Quercus suber Cork

    National Research Council Canada - National Science Library

    Inácio, Vera; Barros, Pedro M; Costa, Augusta; Roussado, Cristóvão; Gonçalves, Elsa; Costa, Rita; Graça, José; Oliveira, M. Margarida; Morais-Cecílio, Leonor

    2017-01-01

    .... suber adult trees growing in three cork oak stands. The relationship between the detected polymorphisms and the diversity of cork quality traits was explored by a marker-trait analysis focusing on the most relevant quality...

  5. Quantitative RT-PCR analysis of differentially expressed genes in Quercus suber in response to Phytophthora cinnamomi infection.

    Science.gov (United States)

    Ebadzad, Ghazal; Cravador, Alfredo

    2014-01-01

    cDNA-AFLP methodology was used to gain insight into gene fragments differentially present in the mRNA profiles of Quercus suber roots infected with zoospores of Phytophthora cinnamomi at different post challenge time points. Fifty-three transcript-derived fragments (TDFs) were identified and sequenced. Six candidate genes were selected based on their expression patterns and homology to genes known to play a role in defence. They encode a cinnamyl alcohol dehydrogenase2 (QsCAD2), a protein disulphide isomerase (QsPDI), a CC-NBS-LRR resistance protein (QsRPc), a thaumatin-like protein (QsTLP), a chitinase (QsCHI) and a 1,3-β-glucanase (QsGlu). Evaluation of the expression of these genes by quantitative polymerase chain reaction (qPCR) revealed that transcript levels of QsRPc, QsCHI, QsCAD2 and QsPDI increased during the first 24 h post-inoculation, while those of thaumatin-like protein decreased. No differential expression was observed for 1,3-β-glucanase (QsGlu). Four candidate reference genes, polymerase II (QsRPII), eukaryotic translation initiation factor 5A (QsEIF-5A), β-tubulin (QsTUB) and a medium subunit family protein of clathrin adaptor complexes (QsCACs) were assessed to determine the most stable internal references for qRT-PCR normalization in the Phytophthora-Q. suber pathosystem in root tissues. Those found to be more stable, QsRPII and QsCACs, were used as internal reference in the present work. Knowledge on the Quercus defence mechanisms against biotic stress is scarce. This study provides an insight into the gene profiling of a few important genes of Q. suber in response to P. cinnamomi infection contributing to the knowledge of the molecular interactions involving Quercus and root pathogens that can be useful in the future to understand the mechanisms underlying oak resistance to soil-borne oomycetes.

  6. Contrasting nuclear and cytoplasmic exchanges between phylogenetically distant oak species (Quercus suber L. and Q. ilex L.) in Southern France: inferring crosses and dynamics.

    Science.gov (United States)

    Mir, C; Jarne, P; Sarda, V; Bonin, A; Lumaret, R

    2009-03-01

    Gene flow is particularly frequent in the genus Quercus (oaks), especially between closely related species. We focus here on Quercus ilex and the cork-producing Quercus suber, which occasionally hybridize although they are phylogenetically markedly separated. Morphological observations were combined with both allozymic and chloroplastic diagnostic markers to characterize hybridization and introgression and to infer their dynamics in two French regions (French Catalonia and Provence), which are separated by several hundred kilometres. Some hybrids were found in both regions, indicating recent hybridization events. As expected from previous studies, most hybrids resulted from female symbol Q. ilex x male symbol Q. suber crosses, but our data showed that the reciprocal cross is also possible. Partial independence between nuclear and chloroplastic introgression was observed in the two species. Nuclear introgression was limited in both species and both regions, with no preferred direction. In Provence, chloroplastic introgression was very rare in both species. Conversely, all Q. suber individuals from French Catalonia were introgressed by Q. ilex chlorotypes. This might be explained by introgression in the Iberian Peninsula antedating the first occurrence of the two species in French Catalonia. We also observed a new chlorotype that was created locally, and was exchanged between the two species. However, the two species still remain genetically differentiated. The dynamics and complexity of exchanges and the factors determining them (including human management of Q. suber) are discussed.

  7. Low temperature during winter elicits differential responses among populations of the Mediterranean evergreen cork oak (Quercus suber).

    Science.gov (United States)

    Aranda, I; Castro, L; Alía, R; Pardos, J A; Gil, L

    2005-08-01

    Populations of cork oak (Quercus suber L.) were assessed for seasonal and inter-population variability in, and temperature responses of, the ratio between light-induced variable and maximum fluorescence of chlorophyll, Fv/Fm, considered a surrogate for the maximum photochemical efficiency of photosystem II (PSII). Seedlings from 10 populations throughout the distribution range of Q. suber in the Mediterranean basin were grown in a common garden in central Spain. The Fv/Fm ratio of dark-adapted leaves was measured at dawn every month for 2 years. Air temperature was recorded at a nearby climatic station. During the summer, when maximum air temperatures reached 40 degrees C, there were no significant differences in Fv/Fm among populations, but significant differences were seen during the winter. In colder months, Fv/Fm ranged in all populations between 0.5-0.6 and 0.2-0.3 in 2001 and 2002, respectively. The variance explained by the population effect was greatest during winter months, especially in 2002, reaching a peak value of 10% when minimum air temperature was below -10 degrees C. Populations originating from warmer sites showed the largest decline in Fv/Fm between the end of 2001 and the beginning of 2002. Thus, a negative linear relationship was established between mean annual temperature at the population source and population mean Fv/Fm recorded in the coldest month in 2002 and normalized by the Fv/Fm spring measurement.

  8. Changes in pectins and MAPKs related to cell development during early microspore embryogenesis in Quercus suber L.

    Science.gov (United States)

    Ramírez, Carmen; Testillano, Pilar S; Pintos, Beatriz; Moreno-Risueño, Miguel A; Bueno, María A; Risueño, María C

    2004-07-01

    The occurrence and significance of changes in cell wall components and signalling molecules has been investigated during early microspore embryogenesis in cork oak (Quercus suber L.) in relation to cell proliferation and cell differentiation. Microspore embryogenesis has been induced in in vitro anther cultures of Q. suber by the application of a stress treatment of 33 degrees C. After the treatment, microspores at the responsive developmental stage of vacuolate microspore switched towards proliferation and the embryogenesis pathway to further produce haploid plantlets. Ultrastructural and immunocytochemical analysis revealed changes in cell organisation after induction at different developmental stages, the cellular features displayed being in relation to the activation of proliferative activity and the beginning of differentiation in young and late proembryos. Immunogold labelling with JIM5 and JIM7 antibodies showed a different presence of pectin and level of its esterification in cell walls at different developmental stages. Non-esterified pectins were found in higher proportions in cells of late proembryos, suggesting that pectin de-esterification could be related to the beginning of differentiation. The presence and subcellular distribution of Erk 1/2 MAPK homologues have been investigated by immunoblotting, immunofluorescence and immunogold labelling. The results showed an increase in the expression of these proteins with a high presence in the nucleus, during early microspore proembryos development. The reported changes during early microspore embryogenesis are modulated in relation to proliferation and differentiation events. These findings provided new evidences for a role of MAPK signalling pathways in early microspore embryogenesis, specifically in proliferation, and would confer information for the cell fate and the direction of the cell development.

  9. Antifungal activity of acetone extracts from Punica granatum L., Quercus suber L. and Vicia faba L.

    Science.gov (United States)

    Akroum, S

    2017-03-01

    Human and animal mycoses become more frequent and more resistant to traditional treatments. In this work, we tested the in vitro antifungal activity of acetonic extracts of Punica granatum L., Quercus suber L. and Vicia faba L. against seven pathogen fungi and the in vivo antifungal activity against Candida albicans and Trichophyton mentagrophytes. The phytochemical screening was also carried out and showed that the extracts contained mainly proanthocyanidins. Other polyphenols were also present but in low quantity. The acetone extract of V. faba L. gave a good in vitro inhibition of yeasts and was the most active for treating candidiasis in mice. It decreased the percentage of mortality with only 20μg. But the in vivo antifungal activity of this extract on T. mentagrophytes was low. It only showed a small diminution of crusting and erythema after the administration of 100μg. On the contrary, the acetone extracts of P. granatum L. had a poor activity against yeasts and a better one against moulds. It gave the best in vivo antifungal activity against T. mentagrophytes by healing animals with 40μg. The extract of P. granatum L. gave also an interesting in vivo antifungal activity against T. mentagrophytes with an active dose of 80μg.

  10. Structural study of the zinc and cadmium complexes of a type 2 plant (Quercus suber) metallothionein: insights by vibrational spectroscopy.

    Science.gov (United States)

    Domènech, Jordi; Tinti, Anna; Capdevila, Mercè; Atrian, Silvia; Torreggiani, Armida

    2007-06-15

    Zn- and Cd-complexes of Quercus suber metallothionein (QsMT) were obtained by in vivo-synthesis, in order to obtain physiologically representative aggregates, and characterized by spectrometric and spectroscopic methods. The secondary structure elements and the coordination environments of the metal binding sites of the two aggregates were determined, as well as the main metal-containing species formed. The results obtained from the analysis of the Raman and IR spectra reveal that these metal-MT complexes predominantly contain beta-sheet elements (about 60%), whereas they lack alpha-helices. These structural features slightly depend on the divalent metal bound. In particular, Cd(II) binding to QsMT induces a slight increase of the beta-sheet percentage, as well as a decrease in beta-turn elements with respect to Zn(II) binding. Conversely, the in vivo capability of QsMT to inglobe metal and sulfide ions is metal-depending. Spectroscopic vibrational data also confirm the presence of sulfide ligands in the metal clusters of both Zn- and Cd-QsMT, while the participation of the spacer His residue in metal coordination was only found in Cd-QsMT, in agreement with the CD results. Overall data suggest different coordination environments for Zn(II) and Cd(II) ions in QsMT.

  11. Water-use efficiency in cork oak (Quercus suber) is modified by the interaction of water and light availabilities.

    Science.gov (United States)

    Aranda, Ismael; Pardos, Marta; Puértolas, Jaime; Jiménez, Maria Dolores; Pardos, Jose Alberto

    2007-05-01

    We studied the interaction of light and water on water-use efficiency in cork oak (Quercus suber L.) seedlings. One-year-old cork oak seedlings were grown in pots in a factorial experiment with four light treatments (68, 50, 15 and 5% of full sunlight) and two irrigation regimes: well watered (WW) and moderate drought stress (WS). Leaf predawn water potential, which was measured at the end of each of two cycles, did not differ among the light treatments. Water-use efficiency, assessed by carbon isotope composition (delta(13)C), tended to increase with increasing irradiance. The trend was similar in the WW and WS treatments, though with lower delta(13)C in all light treatments in the WW irrigation regime. Specific leaf area increased with decreasing irradiance, and was inversely correlated with delta(13)C. Thus, changes in delta(13)C could be explained in part by light-induced modifications in leaf morphology. The relationship between stomatal conductance to water vapor and net photosynthesis on a leaf area basis confirmed that seedlings in higher irradiances maintained a higher rate of carbon uptake at a particular stomatal conductance, implying that shaded seedlings have a lower water-use efficiency that is unrelated to water availability.

  12. STUDY OF THE VARIABILITY IN CHEMICAL COMPOSITION OF BARK LAYERS OF QUERCUS SUBER L. FROM DIFFERENT PRODUCTION AREAS

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    Patricia Jové

    2011-04-01

    Full Text Available Cork is the bark of the cork oak tree (Quercus suber L, a renewable and biodegradable raw bioresource concentrated mainly in the Mediterranean region. Development of its potential uses as a biosorbent will require the investigation of its chemical composition; such information can be of help to understand its interactions with organic pollutants. The present study investigates the summative chemical composition of three bark layers (back, cork, and belly of five Spanish cork samples and one cork sample from Portugal. Suberin was the main component in all the samples (21.1 to 53.1%, followed by lignin (14.8 to 31%, holocellulose (2.3 to 33.6%, extractives (7.3 to 20.4%, and ash (0.4 to 3.3%. The Kruskal-Wallis test was used to determine whether the variations in chemical composition with respect to the production area and bark layers were significant. The results indicate that, with respect to the bark layer, significant differences were found only for suberin and holocellulose contents: they were higher in the belly and cork than in the back. Based on the results presented, cork is a material with a lot of potential because of its heterogeneity in chemical composition.

  13. Development of cork oak (Quercus suber L.) seedlings in response to tree shelters and mulching in northwestern Tunisia

    Institute of Scientific and Technical Information of China (English)

    Taher Mechergui; Marta Pardos; Naceur Boussaidi; Brahim Hasnaoui; Douglass F.Jacobs

    2013-01-01

    The need for reforestation in cork oak (Quercus suber L.)areas is challenged by difficulties.Principal among these is herbivory of young plants,vegetative competition,and slow growth rates of cork oak seedlings.We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia.We tested three tree shelter treatments (non-vented,vented,and control) to shield seedlings from animal damage and five mulch types to control competing vegetation (Italian Stone Pine,Lentisk,combination of Italian Stone Pine and Lentisk (organic mulches),gravel (inorganic mulch) and no mulch).At the end of the two-year experiment,sheltered seedlings were 89-99% taller than unsheltered seedlings and had higher numbers and lengths of shoot growth flushes.In contrast,both stem diameter growth and dry weight biomass (from samples extracted after two years)were significantly reduced inside tree shelters.Root-to-shoot ratio was not significantly different in sheltered vs.unsheltered seedlings,suggesting that tree shelters do not adversely affect this parameter.Mulching alone did not favour growth,but could be beneficial when combined with tree shelters.The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter,height and stem volume growth.

  14. Sewage sludge effects on mesofauna and cork oak (Quercus suber L.) leaves decomposition in a Mediterranean forest firebreak.

    Science.gov (United States)

    Pernin, Céline; Cortet, Jérôme; Joffre, Richard; Le Petit, Jean; Torre, Franck

    2006-01-01

    Effects of sewage sludge on litter mesofauna communities (Collembola and Acari) and cork oak (Quercus suber L.) leaf litter decomposition have been studied during 18 mo using litterbags in an in situ experimental forest firebreak in southeastern France. The sludge (2.74 t DM ha(-1) yr(-1)) was applied to fertilize and maintain a pasture created on the firebreak. Litterbag colonization had similar dynamics on both the control and fertilized plots and followed a typical Mediterranean pattern showing a greater abundance in spring and autumn and a lower abundance in summer. After 9 mo of litter colonization, Collembola and Acari, but mainly Oribatida, were more abundant on the sludge-fertilized plot. Leaf litter decomposition showed a similar pattern on both plots, but it was faster on the control plot. Furthermore, leaves from the fertilized plot were characterized by greater nitrogen content. Both chemical composition of leaves and sludges and the decomposition state of leaves have significantly affected the mesofauna community composition from each plot.

  15. Drought influence on carbon and water cycling in a Mediterranean Quercus suber L. woodland during the drought year 2012

    Science.gov (United States)

    Piayda, Arndt; Dubbert, Maren; Rebmann, Corinna; Kolle, Olaf; Silva, Filipe Costa e.; Correia, Alexandra; Santos Pereira, Joao; Werner, Christiane; Cuntz, Matthias

    2014-05-01

    Savannah-type ecosystems account for 26-30% of the global gross primary production with water being one of the major driving factors. In Europe, savannah-type woodlands cover an area of about 2-2.5 million ha on the Iberian Peninsula. The recent past has shown there a significant decrease of precipitation in winter and spring as well as a decrease of total annual precipitation. Hence, strong effects on local water balance and carbon sink strength have been reported due to these changes in the precipitation regime. The objective of this study is to quantify changes in the water balance, gross primary productivity and carbon sink strength of a typical Portuguese savannah-type woodland (montado) under the changed precipitation pattern of the drought year 2012 compared to the wet year 2011. The physiological response of the dominant tree species Quercus suber (L.) is evaluated, employing combined photosynthesis and stomatal conductance modelling. Precipitation effectiveness ratio increased up to 122% in the dry year 2012 due to ground water access of the Q. suber trees leaving no water for ground water replenishment. By the lack of water in the upper soil and deep ground water reservoirs, the understorey and overstorey gross primary productions were reduced by 53% and 28% in 2012 compared to 2011, respectively, due to the late onset of the autumn rains in 2011 and an additional severe winter/spring drought. However, on an annual basis, the ecosystem was a carbon sink in both years, with a 61% reduced sink strength in the dry year 2012 compared to the wet 2011. Applying a combined photosynthesis and stomatal conductance model, best model fit to gross primary productivity and transpiration of Q. suber trees could be achieved keeping apparent maximum carboxylation rate V c,max as well as stomatal conductivity parameter m and vapor pressure deficit sensitivity parameter D0 of the stomatal conductance formulation variable. The Q. suber trees showed 20% reduced stomatal

  16. Genetic transformation of cork oak (Quercus suber L.) for herbicide resistance.

    Science.gov (United States)

    Alvarez, Rubén; Alvarez, José M; Humara, Jaime M; Revilla, Angeles; Ordás, Ricardo J

    2009-09-01

    The bar gene was introduced into the cork oak genome. Cork oak embryogenic masses were transformed using the Agrobacterium strain AGL1 which carried the plasmid pBINUbiBar. This vector harbours the genes, nptII and bar, the latter under control of the maize ubiquitin promoter. The transgenic embryogenic lines were cryopreserved. Varying activities of phosphinothricin acetyl transferase were detected among the lines, which carried 1-4 copies of the insert. Molecular and biochemical assays confirmed the stability and expression of the transgenes 3 months after thawing the cultures. These results demonstrate genetic engineering of herbicide tolerance in Quercus spp.

  17. New tools for extracting cork from Quercus suber L.: increasing productivity and reducing damage

    Directory of Open Access Journals (Sweden)

    Jesus Beira Davila

    2014-04-01

    Full Text Available Aim of study: The aim of this study is to test new tools designed to debark cork oak trees: mechanized tools to perform cutting operations (IPLA-Morell, Stihl MC200 and COVELESS and manual tools to separate and extract the cork (cork pincers, MIJURO.Area of study: Southwestern Spain.Material and methods: One of the longstanding problems affecting the sector is the shortage of skilled labor to perform debarking due to the difficulty of handling axes and the temporary nature of the work. To overcome these problems, four debarking systems using the new tools were designed according to the morphological properties of cork oak. The viability of the debarking systems were evaluated based on productivity (kg · person–1 · hour–1, production costs (€ · t1 and percentage of pieces smaller than 400 cm2 (%, and compared with the traditional system. Debarking quality and operator experience were also evaluated. A total of 204 trees were debarked.Main results: The new systems obtain better results: productivity is higher, the percentage of pieces is slightly lower and production costs are reduced, except for one system. Debarking quality improves with the new tools as cork is extracted in a more precise and cleaner manner, thus permitting cork manufacturers to obtain higher yields from the cork planks.Research highlights: Semi-skilled operators using the new tools obtain very similar results to skilled operators using axes. This would therefore resolve the problem of the lack of skilled labor, while improving the working conditions of operators. The results demonstrate that the new tools are viable for cork debarking and can bring potential benefits to the sector.Key words: Q. suber L.; cork debarking; mechanization; productivity; cork stripping damage; axe; IPLA_Morell, Sthil MC 200, COVELESS.

  18. Is cork oak (Quercus suber L. woodland loss driven by eucalyptus plantation? A case-study in southwestern Portugal

    Directory of Open Access Journals (Sweden)

    Costa A

    2014-06-01

    Full Text Available Mediterranean landscapes with open cork oak (Quercus suber L. woodlands have recently experienced drastic changes in southwestern Portugal. Changes in agricultural activities, the traditional driver of the economy in this region, led to new land uses, such as long-term set aside (shrublands and eucalyptus plantations. A study was conducted on the oak woodland landscape dynamics over a 50-year period (from 1958 to 2007 in order to assess the effect of different biophysical conditions on landscape spatial changes, and to identify the resilience of lanscape composition to different disturbances (e.g., socio-economic changes and wildfires. Land use changes over two consecutive periods (1958-1995 and 1995-2007 were inferred by spatial analysis of land cover data (aerial photographs and related to landscape physical attributes (slope and soil type. A transition matrix of four vegetation land-cover classes was obtained, allowing the assessment of the landscape composition changes bewteen the two above periods. Results showed that lansdcape in 1958 was largely occupied by open farmland, with large patches of open oak woodlands on steep slopes surrounding watercourses. Open farmland and shrubland drastically declined from 1958 to 1995, while eucalyptus plantation exhibited a dramatic expansion. Although large areas of cork oak forest turned into eucalyptus plantation, the net loss of oak forest was low and counterbalanced by its increment on former open farmland. The occurrence of a wildfire in 2003 promoted a dramatic decrease in cork oak woodlands, which mostly turned into shrubland. However, shrubland may be considered “safe sites” for ecological succession, ensuring natural cork oak regeneration and the colonisation of neighboring areas.

  19. The Cd(II)-binding abilities of recombinant Quercus suber metallothionein: bridging the gap between phytochelatins and metallothioneins.

    Science.gov (United States)

    Domènech, Jordi; Orihuela, Rubén; Mir, Gisela; Molinas, Marisa; Atrian, Sílvia; Capdevila, Mercè

    2007-08-01

    In this work, we have analyzed both at stoichiometric and at conformational level the Cd(II)-binding features of a type 2 plant metallothionein (MT) (the cork oak, Quercus suber, QsMT). To this end four peptides, the wild-type QsMT and three constructs previously engineered to characterize its Zn(II)- and Cu(I)-binding behaviour, were heterologously produced in Escherichia coli cultures supplemented with Cd(II), and the corresponding complexes were purified up to homogeneity. The Cd(II)-binding ability of these recombinant peptides was determined through the chemical, spectroscopic and spectrometric characterization of the recovered clusters. Recombinant synthesis of the four QsMT peptides in cadmium-rich media rendered complexes with a higher metal content than those obtained from zinc-supplemented cultures and, consequently, the recovered Cd(II) species are nonisostructural to those of Zn(II). Also of interest is the fact that three out of the four peptides yielded recombinant preparations that included S(2-)-containing Cd(II) complexes as major species. Subsequently, the in vitro Zn(II)/Cd(II) replacement reactions were studied, as well as the in vitro acid denaturation and S(2-) renaturation reactions. Finally, the capacity of the four peptides for preventing cadmium deleterious effects in yeast cells was tested through complementation assays. Consideration of all the results enables us to suggest a hairpin folding model for this typical type 2 plant Cd(II)-MT complex, as well as a nonnegligible role of the spacer in the detoxification function of QsMT towards cadmium.

  20. Quercus suber cork extract displays a tensor and smoothing effect on human skin: an in vivo study.

    Science.gov (United States)

    Coquet, C; Bauza, E; Oberto, G; Berghi, A; Farnet, A M; Ferré, E; Peyronel, D; Dal Farra, C; Domloge, N

    2005-01-01

    Recently, it has become indispensable for anti-aging active ingredients to provide a visible and immediate smoothing antiwrinkle effect. In Quercus suber, suberin is the most important structural component of cork cell walls. Studies have shown that suberin is made up mostly of hydroxycarboxylic acids and that it is endowed with many special mechanical and chemical properties that evoke a possible smoothing effect on the surface of the skin. Therefore, we were interested in investigating the effect of this cork extract on the skin's surface in a double-blind clinical study. The study was conducted in 15 healthy volunteers, aged 22 to 52 years. The volunteers applied a gel formula with 3% of cork extract, or placebo gel, on each forearm. Skin surface roughness was evaluated visually by pictures and by silicone replicas 1 and 2 h after application, followed by statistical analysis using the matched-pairs McNemar statistical test. McNemar analysis of the pictures revealed that application of cork extract on the skin resulted in a highly significant reduction of roughness 1 h after application. This effect was observed in 73.3% of volunteers. Two hours after cork extract application, a highly significant improvement of skin roughness was found in 78.6% of volunteers. Moreover, silicone replica treatment confirmed significant improvement in average of roughness at 2 h. These results demonstrate that cork extract provides a remarkable and highly significant tensor and smoothing effect on the skin, which could be of great use in anti-aging skin care products.

  1. Using Landsat 8 imagery in detecting cork oak (Quercus suber L. woodlands: a case study in Calabria (Italy

    Directory of Open Access Journals (Sweden)

    Giuseppe Modica

    2016-12-01

    Full Text Available In the Mediterranean basin, cork oak (Quercus suber L. woodlands are characteristic and widespread forestry ecosystems. Though presenting significant economic potential as a renewable resource, they are not adequately valorised, in spite of a growing market demand for cork and cork-based products, which are appreciated, today, for their use in sustainable building. In this respect, cork meets the needs of the building industry in responding to the growing demand for quality products, which are eco- and energy-friendly and hygienically safe. Moreover, European cultural and biodiversity value has been attributed to cork oak woodlands and their most significant examples have been included in the Natura 2000 framework. So far, in some countries like Italy, the territorial distribution and characterisation of cork oak woodlands have not been adequately investigated. This study provides a method for mapping the actual presence of cork oak woodlands and for assessing their potential distribution. Special attention was given to the characterisation of cork oak spectral signature. To this end, Landsat 8 satellite images, digital photointerpretation and in situ surveys were implemented. The work carried out allows assessing the effectiveness of GIS and remote sensing techniques coupled with ancillary data and tools, and their applicability for the development of a comprehensive mapping and monitoring system of cork oak woodlands in Mediterranean ecosystems. Such techniques are vital to develop a detailed management strategy and to assist restoration activities and the economic assessment of semi-natural habitats. A case study, carried out in two different locations in Calabria (Italy, is provided.

  2. Endemic North African Quercus afares Pomel originates from hybridisation between two genetically very distant oak species (Q. suber L. and Q. canariensis Willd.): evidence from nuclear and cytoplasmic markers.

    Science.gov (United States)

    Mir, C; Toumi, L; Jarne, P; Sarda, V; Di Giusto, F; Lumaret, R

    2006-02-01

    Hybridisation is a potent force in plant evolution, although there are few reported examples of stabilised species that have been created through homoploid hybridisation. We focus here on Quercus afares, an endemic North African species that combines morphological, physiological and ecological traits of both Q. suber and Q. canariensis, two phylogenetically distant species. These two species are sympatric with Q. afares over most of its distribution. We studied two Q. afares populations (one from Algeria and one from Tunisia), as well as several populations of both Q. suber and Q. canariensis sampled both within and outside areas where these species overlap with Q. afares. A genetic analysis was conducted using both nuclear (allozymes) and chloroplastic markers, which shows that Q. afares originates from a Q. suber x Q. canariensis hybridisation. At most loci, Q. afares predominantly possesses alleles from Q. suber, suggesting that the initial cross between Q. suber and Q. canariensis was followed by backcrossing with Q. suber. Other hypotheses that can account for this result, including genetic drift, gene silencing, gene conversion and selection, are discussed. A single Q. suber chlorotype was detected, and all Q. afares individuals displayed this chlorotype, indicating that Q. suber was the maternal parent. Q. afares is genetically, morphologically and ecologically differentiated from its parental species, and can therefore be considered as a stabilised hybrid species.

  3. Chloroplast DNA analysis of Tunisian cork oak populations (Quercus suber L.): sequence variations and molecular evolution of the trnL (UAA)-trnF (GAA) region.

    Science.gov (United States)

    Abdessamad, A; Baraket, G; Sakka, H; Ammari, Y; Ksontini, M; Hannachi, A Salhi

    2016-10-24

    Sequences of the trnL-trnF spacer and combined trnL-trnF region in chloroplast DNA of cork oak (Quercus suber L.) were analyzed to detect polymorphisms and to elucidate molecular evolution and demographic history. The aligned sequences varied in length and nucleotide composition. The overall ratio of transition/transversion (ti/tv) of 0.724 for the intergenic spacer and 0.258 for the pooled sequences were estimated, and indicated that transversions are more frequent than transitions. The molecular evolution and demographic history of Q. suber were investigated. Neutrality tests (Tajima's D and Fu and Li) ruled out the null hypothesis of a strictly neutral model, and Fu's Fs and Ramos-Onsins and Rozas' R2 confirmed the recent expansion of cork oak trees, validating its persistency in North Africa since the last glaciation during the Quaternary. The observed uni-modal mismatch distribution and the Harpending's raggedness index confirmed the demographic history model for cork oak. A phylogenetic dendrogram showed that the distribution of Q. suber trees occurs independently of geographical origin, the relief of the population site, and the bioclimatic stages. The molecular history and cytoplasmic diversity suggest that in situ and ex situ conservation strategies can be recommended for preserving landscape value and facing predictable future climatic changes.

  4. [Effects of fire recurrence on fire behaviour in cork oak woodlands (Quercus suber L.) and Mediterranean shrublands over the last fifty years].

    Science.gov (United States)

    Schaffhauser, Alice; Pimont, François; Curt, Thomas; Cassagne, Nathalie; Dupuy, Jean-Luc; Tatoni, Thierry

    2015-12-01

    Past fire recurrence impacts the vegetation structure, and it is consequently hypothesized to alter its future fire behaviour. We examined the fire behaviour in shrubland-forest mosaics of southeastern France, which were organized along a range of fire frequency (0 to 3-4 fires along the past 50 years) and had different time intervals between fires. The mosaic was dominated by Quercus suber L. and Erica-Cistus shrubland communities. We described the vegetation structure through measurements of tree height, base of tree crown or shrub layer, mean diameter, cover, plant water content and bulk density. We used the physical model Firetec to simulate the fire behaviour. Fire intensity, fire spread, plant water content and biomass loss varied significantly according to fire recurrence and vegetation structure, mainly linked to the time since the last fire, then the number of fires. These results confirm that past fire recurrence affects future fire behaviour, with multi-layered vegetation (particularly high shrublands) producing more intense fires, contrary to submature Quercus woodlands that have not burnt since 1959 and that are unlikely to reburn. Further simulations, with more vegetation scenes according to shrub and canopy covers, will complete this study in order to discuss the fire propagation risk in heterogeneous vegetation, particularly in the Mediterranean area, with a view to a local management of these ecosystems.

  5. Molecular organization of the 25S-18S rDNA IGS of Fagus sylvatica and Quercus suber: a comparative analysis.

    Science.gov (United States)

    Inácio, Vera; Rocheta, Margarida; Morais-Cecílio, Leonor

    2014-01-01

    The 35S ribosomal DNA (rDNA) units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (IGS) containing functional elements involved in the regulation of transcription of downstream rRNA genes. In the present work, we have compared the IGS molecular organizations in two divergent species of Fagaceae, Fagus sylvatica and Quercus suber, aiming to comprehend the evolution of the IGS sequences within the family. Self- and cross-hybridization FISH was done on representative species of the Fagaceae. The IGS length variability and the methylation level of 18 and 25S rRNA genes were assessed in representatives of three genera of this family: Fagus, Quercus and Castanea. The intergenic spacers in Beech and Cork Oak showed similar overall organizations comprising putative functional elements needed for rRNA gene activity and containing a non-transcribed spacer (NTS), a promoter region, and a 5'-external transcribed spacer. In the NTS: the sub-repeats structure in Beech is more organized than in Cork Oak, sharing some short motifs which results in the lowest sequence similarity of the entire IGS; the AT-rich region differed in both spacers by a GC-rich block inserted in Cork Oak. The 5'-ETS is the region with the higher similarity, having nonetheless different lengths. FISH with the NTS-5'-ETS revealed fainter signals in cross-hybridization in agreement with the divergence between genera. The diversity of IGS lengths revealed variants from ∼ 2 kb in Fagus, and Quercus up to 5.3 kb in Castanea, and a lack of correlation between the number of variants and the number of rDNA loci in several species. Methylation of 25S Bam HI site was confirmed in all species and detected for the first time in the 18S of Q. suber and Q. faginea. These results provide important clues for the evolutionary trends of the rDNA 25S-18S IGS in the Fagaceae family.

  6. Molecular organization of the 25S-18S rDNA IGS of Fagus sylvatica and Quercus suber: a comparative analysis.

    Directory of Open Access Journals (Sweden)

    Vera Inácio

    Full Text Available The 35S ribosomal DNA (rDNA units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (IGS containing functional elements involved in the regulation of transcription of downstream rRNA genes. In the present work, we have compared the IGS molecular organizations in two divergent species of Fagaceae, Fagus sylvatica and Quercus suber, aiming to comprehend the evolution of the IGS sequences within the family. Self- and cross-hybridization FISH was done on representative species of the Fagaceae. The IGS length variability and the methylation level of 18 and 25S rRNA genes were assessed in representatives of three genera of this family: Fagus, Quercus and Castanea. The intergenic spacers in Beech and Cork Oak showed similar overall organizations comprising putative functional elements needed for rRNA gene activity and containing a non-transcribed spacer (NTS, a promoter region, and a 5'-external transcribed spacer. In the NTS: the sub-repeats structure in Beech is more organized than in Cork Oak, sharing some short motifs which results in the lowest sequence similarity of the entire IGS; the AT-rich region differed in both spacers by a GC-rich block inserted in Cork Oak. The 5'-ETS is the region with the higher similarity, having nonetheless different lengths. FISH with the NTS-5'-ETS revealed fainter signals in cross-hybridization in agreement with the divergence between genera. The diversity of IGS lengths revealed variants from ∼ 2 kb in Fagus, and Quercus up to 5.3 kb in Castanea, and a lack of correlation between the number of variants and the number of rDNA loci in several species. Methylation of 25S Bam HI site was confirmed in all species and detected for the first time in the 18S of Q. suber and Q. faginea. These results provide important clues for the evolutionary trends of the rDNA 25S-18S IGS in the Fagaceae family.

  7. Oxygen isotope signatures of transpired water vapor - the role of isotopic non-steady-state transpiration of Mediterranean cork-oaks (Quercus suber L.)under natural conditions

    Science.gov (United States)

    Dubbert, Maren; Piayda, Arndt; Cuntz, Matthias; Werner, Christiane

    2014-05-01

    Oxygen isotope signatures of transpired water vapor (δT) are a powerful tracer of water movement from plants to the global scale, but little is known on short-term variability of δT as direct high-frequency measurements are lacking. A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes and δT to evaluate a modeling approach and investigate the role of isotopic non-steady-state transpiration under natural conditions in distinct seasons in cork-oaks (Quercus suber L.). The isotope signature of transpiration (δT) always deviated from steady-state predictions (ΔT) throughout most of the day even when leaf water at the evaporating sites is near isotopic steady-state. Thus, ΔT is further amplified compared to deviations of leaf water isotopes from steady-state, specifically in dry conditions. High agreement was found for direct estimates and modeled ΔT assuming non-steady-state conditions of leaf-water at the evaporating sites. Strong isoforcing on the atmosphere of transpiration in isotopic non-steady-state imply that short-term variations in δT have likely consequences for large-scale applications, e.g. partitioning of ecosystem evapotranspiration or carbon fluxes using C18O16O, or satellite-based applications.

  8. The role of forest fire severity on vegetation recovery after 18 years. Implications for forest management of Quercus suber L. in Iberian Peninsula

    Science.gov (United States)

    Francos, Marcos; Úbeda, Xavier; Tort, Joan; Panareda, Josep María; Cerdà, Artemio

    2016-10-01

    Wildfires are a widespread phenomenon in Mediterranean environments. Wildfires result in different fire severities, and then in contrasting plant cover and floristic composition. This paper analyses the recovery of the vegetation eighteen years after a wildfire in Catalonia. The Pinus pinaster ssp. forest was affected by three different severities in July 1994, and studied the spring of 1995 and again in 2008. After eighteen years (2012), our research found that burnt sites constitute a dense forest with a broad variety of species, including many young pines, shrubs and herbaceous plants, but that the risk of fire remains very high, due to the large quantity of fuel and the flammability of the species. The management of the post-fire is critical when high severity fires take places, and it is recommended that high-severity fires must be avoided for a sustainable forest management. We recommend that once the timber (Pinus plantations) production is not profitable, Quercus suber L. and Pinus pinaster ssp. forest should be promoted, and pine plantations avoided.

  9. Effects of partial defoliation on carbon and nitrogen partitioning and photosynthetic carbon uptake by two-year-old cork oak (Quercus suber) saplings.

    Science.gov (United States)

    Cerasoli, S; Scartazza, A; Brugnoli, E; Chaves, M M; Pereira, J S

    2004-01-01

    At the end of the growing season in late July, 20-month-old cork oak (Quercus suber L.) saplings were partially defoliated (63% of leaf area) to evaluate their ability to recover leaf area after defoliation. At 18 and 127 days after defoliation, changes in starch and nitrogen pools were determined in leaves and perennial organs, and variations in photosynthetic carbon uptake were investigated. To determine the role of stored nitrogen in regrowth after defoliation, plant nitrogen was labeled in the previous winter by enriching the nutrient solution with 15N. Plants recovered the lost leaf area in 127 days. Although there was remobilization of starch and nitrogen from leaves and perennial organs, the availability of resources for growth in the following spring was not decreased by defoliation. On the contrary, starch concentration in coarse roots was higher in defoliated saplings than in control saplings, presumably as a result of the higher net CO2 exchange rate in newly developed leaves compared with pre-existing leaves.

  10. The impact of drought on leaf physiology of Quercus suber L. trees: comparison of an extreme drought event with chronic rainfall reduction.

    Science.gov (United States)

    Grant, Olga M; Tronina, Lukasz; Ramalho, José Cochicho; Kurz Besson, Cathy; Lobo-do-Vale, Raquel; Santos Pereira, João; Jones, Hamlyn G; Chaves, M Manuela

    2010-10-01

    Understanding the responses of cork oak (Quercus suber L.) to actual and predicted summer conditions is essential to determine the future sustainability of cork oak woodlands in Iberia. Thermal imaging may provide a rapid method for monitoring the extent of stress. The ecophysiology of cork trees was studied over three years. Three treatments were applied by means of rainfall capture and irrigation, with plots receiving 120%, 100%, or 80% of natural precipitation. Despite stomatal closure, detected using both thermal imaging and porometry, leaf water potential fell during the summer, most drastically during the third year of accumulative stress. The quantum efficiency (ΦPSII) and the maximum efficiency Fv' /FM' of photosystem II also fell more intensely over the third summer, while non-photochemical quenching (NPQ) increased. The reduced precipitation treatment sporadically further reduced leaf water potential, stomatal conductance (gs), IG (an index of gs derived from thermal imaging), ΦPSII, and Fv' /FM', and increased leaf temperature and NPQ. It is concluded that these are very resilient trees since they were only severely affected in the third year of severe drought (the third year registering 45% less rainfall than average), and removing 20% of rainfall had a limited impact..

  11. Differences in fine-scale genetic structure and dispersal in Quercus ilex L. and Q. suber L.: consequences for regeneration of mediterranean open woods.

    Science.gov (United States)

    Soto, A; Lorenzo, Z; Gil, L

    2007-12-01

    Cork oak (Quercus suber L.) and holm oak (Q. ilex L.) are among the most important tree species (economically and ecologically) in the Western Mediterranean region, where they define unique open woods (created and maintained by man) known as 'dehesas' in Spain. However, these formations are under increasing threat due to the lack of regeneration. We have analysed spatial genetic structure in a mixed parkland; inferences about gene dispersal have also been performed, according to the isolation by distance model. Noticeable differences have been detected between the species, despite their similar ecological roles. Restricted effective dispersal leads to kin structures in cork oak, up to 70 m, while no genetic structure is observed in holm oak. Our results suggest a very effective dispersal for the latter, with a local historical gene flow estimated between 55 and 95 m. This is the first time regeneration of Mediterranean oak parklands has been assessed from a genetic perspective. Effective gene flow detected for holm oaks allows us to discount the risk of inbreeding over successive generations. Thus, regeneration of Q. ilex dehesas will just require action directed to help the settlement of the saplings (such as limiting grazing). However, in those cases where densities are too low, more intense forestation (such as plantation and/or establishment of appropriate shelter) will be needed. The 'density threshold' for initiating regeneration will probably be higher for cork oak, due to its more limited dispersal and minor full-light tolerance.

  12. Drought impact on carbon and water cycling in a Mediterranean Quercus suber L. woodland during the extreme drought event in 2012

    Science.gov (United States)

    Piayda, Arndt; Dubbert, Maren; Rebmann, Corinna; Kolle, Olaf; Silva, Filipe Costa e.; Correia, Alexandra; Pereira, João S.; Werner, Christiane; Cuntz, Matthias

    2015-04-01

    Savannah-type ecosystems account for 26-30% of global gross primary productivity GPP, with water being one of the major driving factors. In Europe, savannah-type woodlands cover an area of about 1.5 million ha. Here, the recent past has shown a significant decrease in precipitation P in winter and spring as well as a decrease in total annual precipitation. Strong effects on local water balance and carbon sink strength have thus been reported due to changes in precipitation regime. The objective of this study is to quantify the impact of the extreme drought event in 2012 on the water balance, gross primary productivity and carbon sink strength of a typical Portuguese cork-oak woodland (montado) compared to the wet year of 2011. Physiological responses of the dominant tree species Quercus suber (L.) are disentangled employing combined photosynthesis and stomatal conductance modelling. Precipitation effectiveness ET/P increased from 86% in 2011 to 122% in the 2012 dry year due to deep soil or groundwater access of the Q. suber trees leaving no water for groundwater replenishment. Understorey and overstorey GPP were strongly reduced, by 53 and 28%, respectively, in 2012 compared to 2011, due to the late onset of the autumn rains in 2011 and an additional severe winter/spring drought. However, the ecosystem was still a carbon sink in both years, but with a 38% reduced sink strength under extreme drought in 2012 compared to 2011. The combined photosynthesis-stomatal conductance model yielded the best results if it was allowed to adjust photosynthetic and stomatal parameters simultaneously. If stomatal response was modelled with the Leuning approach, which allows for a different sensitivity to vapour pressure deficit, the stomatal model parameters were highly coupled. A change in either of the parameters needed to be compensated by the other to guarantee a stable sensitivity of stomatal conductance to assimilation, independent of variations in vapour pressure deficit. The

  13. Drought impact on carbon and water cycling in a Mediterranean Quercus suber L. woodland during the extreme drought event in 2012

    Directory of Open Access Journals (Sweden)

    A. Piayda

    2014-07-01

    Full Text Available Savannah-type ecosystems account for 26–30% of global gross primary productivity GPP with water being one of the major driving factors. In Europe, savannah-type woodlands cover an area of about 1.5 million ha. Here, the recent past has shown a significant decrease of precipitation P in winter and spring as well as decrease of total annual precipitation. Strong effects on local water balance and carbon sink strength have thus been reported due to changes in precipitation regime. The objective of this study is to quantify the impact of the extreme drought event in 2012 on the water balance, gross primary productivity and carbon sink strength of a typical Portuguese cork-oak woodland (montado compared to the wet year 2011. Physiological responses of the dominant tree species Quercus suber (L. are disentangled, employing combined photosynthesis and stomatal conductance modelling. Precipitation effectiveness ET / P increased from 86% in 2011 to 122% in the dry year 2012 due to deep soil or ground water access of the Q. suber trees leaving no water for ground water replenishment. Understorey and overstorey GPP were strongly reduced by 53% and 28%, respectively, in 2012 compared to 2011 due to the late onset of the autumn rains in 2011 and an additional severe winter/spring drought. However, the ecosystem was still a carbon sink in both years but with a 38% reduced sink strength under extreme drought in 2012 compared to 2011. The combined photosynthesis-stomatal conductance model yielded best results if it was allowed to adjust photosynthetic and stomatal parameters simultaneously. If stomatal response was modelled with the Leuning approach, which allows for a different sensitivity to vapour pressure deficit, the stomatal model parameters were highly coupled. A change in either of the parameters needed to be compensated by the other to guarantee a stable sensitivity of stomatal conductance to assimilation, independently from variations in vapour

  14. 欧洲栓皮栎种子催芽试验%Seed Germination Trial with Cork Oak (Quercus suber)

    Institute of Scientific and Technical Information of China (English)

    佘远国

    2000-01-01

    @@ 欧洲栓皮栎(Quercus rariabilis B1.)是一种重要的软木工业原料.60年代从苏联引种我省,由于疏于管理,目前,全省仅存100株,濒于绝迹.为了拯救优良物种,加大欧洲栓皮栎种质资源收集,加速物种繁殖.实生繁殖时,为了确定合理的播种量以及改进种子贮藏方法,对种子进行不同药剂催芽处理,测定发芽率,平均发芽速,根的生长量,比较不同药剂对种子发芽的影响效果.

  15. Effects of fire temperature on the physical and chemical characteristics of the ash from two plots of Cork oak (Quercus Suber)

    Science.gov (United States)

    Ubeda, X.; Pereira, P.; Outeiro, L.; Martin, D.A.

    2009-01-01

    Cork oak, (Quercus suber) is widely distributed in the Mediterranean region, an area subject to frequent fires. The ash produced by burning can have impacts on the soil status and water resources that can differ according to the temperature reached during fire and the characteristics of the litter, defined as the dead organic matter accumulated on the soil surface prior to the fire. The aim of this work is to determine the physical and chemical characteristics of ash produced in laboratory experiments to approximate conditions typical of fires in this region. The litter of Quercus suber collected from two different plots on the Iberian Peninsula, Mas Bassets (Catalonia) and Albufeira (Portugal), was combusted at different temperatures for 2h. We measured Mass Loss (ML per cent), ash colour and CaCO3 content, pH, Electrical Conductivity (EC) and the major cations (Ca2+, Mg2+, K+ and Na+) released from ash slurries created by mixing ash with deionized water. The results showed that ML per cent is higher at all temperatures in Albufeira samples compared to Mas Bassets samples, except at 550??C, and the rate of loss increases faster with temperature than the Mas Bassets samples. At 150??C the ash colour is yellowish, becoming reddish at 200- 250??C and black at 300??C. Above 400??C the ash is grey/white. This thermal degradation is mostly observed in Albufeira litter. The formation of CaCO3 was identified at a lower temperature in Albufeira litter. At temperatures <300??C, pH and EC values are lower, rising at higher temperatures, especially in Albufeira slurries. The concentration of cations at lower temperatures does not differ substantially from the unburned sample except for Mg2+. The cation concentration increases at medium temperatures and decrease at higher temperatures, especially the concentration of divalent cations. The monovalent cations showed a larger concentration at moderate temperatures, mainly in Albufeira ash slurries. The analysis of the Ca:Mg ratio

  16. Wildfire effects on lipid composition and hydrophobicity of bulk soil and soil size fractions under Quercus suber cover (SW-Spain).

    Science.gov (United States)

    Jiménez-Morillo, Nicasio T; Spangenberg, Jorge E; Miller, Ana Z; Jordán, Antonio; Zavala, Lorena M; González-Vila, Francisco J; González-Pérez, José A

    2017-08-25

    Soil water repellency (hydrophobicity) prevents water from wetting or infiltrating soils, triggering changes in the ecosystems. Fire may develop, enhance or destroy hydrophobicity in previously wettable or water-repellent soils. Soil water repellency is mostly influenced by the quality and quantity of soil organic matter, particularly the lipid fraction. Here we report the results of a study on the effect of fire on the distribution of soil lipids and their role in the hydrophobicity grade of six particle size fractions (2-1, 1-0.5, 0.5-0.25, 0.25-0.1, 0.1-0.05 and <0.05mm) of an Arenosol under Quercus suber canopy at the Doñana National Park (SW-Spain). Hydrophobicity was determined using water drop penetration time test. Field emission scanning electron microscopy (FESEM) was used to assess the presence and morphology of the inorganic and organic soil components in the particle size fractions. Soil lipids were Soxhlet extracted with a dichloromethane-methanol mixture. Fatty acids (FAs) and neutral lipids were separated, derivatized, identified and quantified by gas chromatography/mass spectrometry and gas chromatography/flame ionization detection. The hydrophobicity values of soil samples and fractions were statistically different (P < 0.05), for both, the unburnt and burnt soils, and particle size fractions. All samples displayed a similar distribution of FAs, straight-chain saturated acids in the C14-C32 range, and neutral lipids (n-alkan-1-ols, n-alkanes), only differing in their relative abundances. Among possible biogeochemical mechanisms responsible for the changes in soil lipids, the observed depletion of long chain FAs (C≥24) in the coarse fraction is best explained by thermal cracking caused by the heat of the fire. The enrichment of long chain FAs observed in other fractions suggests possible exogenous additions of charred, lipid-rich, material, like cork suberin or other plant-derived macromolecules (cutins). Principal component analysis was used to

  17. Estructura, dinámica y regeneración de los bosques mixtos de alcornoque (Quercus suber L.) y quejigo moruno (Quercus canariensis Willd.) del sur de la Península Ibérica: una aproximación multiescala.

    OpenAIRE

    Rodríguez Urbieta, Itzíar

    2008-01-01

    Esta Tesis Doctoral se centra en el estudio de la dinámica y estructura de los bosques de alcornoque (Quercus suber) y quejigo moruno (Q. canariensis) del Parque Natural Los Alcornocales (Cádiz, Málaga), con especial énfasis en los procesos de regeneración forestal. Los objetivos principales fueron: i) identificar qué factores históricos y ambientales han determinado la estructura actual de los bosques, y ii) analizar los patrones diferenciales de regeneración del alcornoque y el quejigo a lo...

  18. Representational difference analysis reveals genomic differences between Q. robur and Q. suber: implications for the study of genome evolution in the genus Quercus.

    Science.gov (United States)

    Zoldos, V; Siljak-Yakovlev, S; Papes, D; Sarr, A; Panaud, O

    2001-04-01

    Very similar genome sizes, similar karyotypes and heterochromatin organisation, and identical number/position of ribosomal loci characterise the common oak (Q. robur) and the cork oak (Q. suber), two distantly related oak species. Representational Difference Analysis (RDA) was used to subtract the genome of Q. suber from the genome of Q. robur in order to search for genome differentiation. A library of 400 clones (bearing RDA fragments) representing genome differences between the two species was obtained. Seven Q. robur-specific DNA sequences were analysed with respect to their molecular and chromosome organisation. All belong to the dispersed repetitive component of the genome, as revealed by Southern hybridisation and in situ hybridisation. They are present in the Q. robur genome in between 100 and 700 copies, and are distributed along the length of almost all chromosomes. A search for homologies between RDA fragments and sequences in Genbank revealed similarities of all RDA fragments with known retrotransposons. The RDA fragments were also tested for their presence/absence in the genomes of six additional oak species belonging to different phylogenetic groups, in order to examine the evolutionary dynamics of these DNA sequences.

  19. Growth, ectomycorrhization and biochemical parameters of Quercus ...

    African Journals Online (AJOL)

    daoudi

    2016-09-21

    Sep 21, 2016 ... stomatal conductance and photosynthesis of plants, which changes .... polyphenols were quantified after colorimetric reaction using Folin-. Ciocalteu ..... of different water and light intensities on cork oak (Quercus suber L.).

  20. Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula

    Science.gov (United States)

    Pereira, P.; beda, X.; Martin, D.; Mataix-Solera, J.; Guerrero, C.

    2011-01-01

    Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO2) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40??70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (pwater-soluble Ca, Mg, Na, SiO2 and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements pwater-soluble K and Al and a significant decrease in water-soluble Fe (psamples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy. ?? 2010 Elsevier Inc.

  1. Modelling diameter distributions of Quercus suber L. stands in “Los Alcornocales” Natural Park (Cádiz-Málaga, Spain by using the two-parameter Weibull function

    Directory of Open Access Journals (Sweden)

    A. Calzado

    2013-04-01

    Full Text Available Aim of study: The aim of this work was to model diameter distributions of Quercus suber stands. The ultimate goal was to construct models enabling the development of more affordable forest inventory methods. This is the first study of this type on cork oak forests in the area.Area of study: The area of study is “Los Alcornocales” Natural Park (Cádiz-Málaga, Spain.Material and methods: The diameter distributions of 100 permanent plots were modelled with the two-parameter Weibull function. Distribution parameters were fitted with the non-linear regression, maximum likelihood, moment and percentile-based methods. Goodness of fit with the different methods was compared in terms of number of plots rejected by the Kolmogorov-Smirnov test, bias, mean square error and mean absolute error. The scale and shape parameters in the Weibull function were related to the stand variables by using the parameter prediction model.Main results: The best fitting was obtained with the non-linear regression approach, using as initial values those obtained by maximum likelihood method, the percentage of rejections by the Kolmogorov-Smirnov test was 2% of the total number of cases. The scale parameter (b was successfully modelled in terms of the quadratic mean diameter under cork (R2 adj = 0.99. The shape parameter (c was modelled by using maximum diameter, minimum diameter and plot elevation (R2 adj = 0.40.Research highlights: The proposed model diameter distribution can be a highly useful tool for the inventorying and management of cork oak forests.Key words: maximum likelihood method; moment method; non linear regression approach; parameter prediction model; percentile method; scale parameter; shape parameter.

  2. Cork oak (Quercus suber L.) site rating

    OpenAIRE

    Gonçalves, Ana Cristina; Saraiva Dias, Susana; Gonçalves Ferreira, Alfredo; Ribeiro, Nuno de Almeida

    2004-01-01

    Alentejo cork oak stands are crucial in terms of cork production and sustainability of agrosilvopastoral systems, therefore the development of a tool that allows site zoning, according to cork oak establishment and growth potentials is worthwhile. The site potential and consequently tree development are mainly governed by soil characteristics such as depth, permeability, chemistry, internal drainage, runoff and climate characteristics such as precipitation and temperature. A cork oak site-rat...

  3. Intrapopulation and Interpopulation Genetic Variation of<em>Quercus in Denmark em>in Denmark

    DEFF Research Database (Denmark)

    Siegismund, Hans Redlef; Jensen, Jan Svejgaard

    2001-01-01

    Native Danish oak stands are fragmented and decreasing because of the extensive use of foreign seed sources. Therefore, the population structure of natural Danish oak stands was analysed by means of six polymorphic enzyme loci. A total of 17 stands of Quercus robur L. (including an ‘‘outgroup......-Weinberg proportions, suggesting a low level of inbreeding. The differentiation of the Q. petraea and Q. robur populations was quanti. ed with Wright's F-statistics. The within-species component was populations was quanti. ed with Wright's -statistics. The within-species component was low, 0.022, re¿ ecting the wind...

  4. SORPTION PERFORMANCE OF QUERCUS CERRIS CORK WITH POLYCYCLIC AROMATIC HYDROCARBONS AND TOXICITY TESTING

    Directory of Open Access Journals (Sweden)

    M. Àngels Olivella

    2011-06-01

    Full Text Available Quercus cerris is an important oak species extended in large areas of Eastern Europe and Minor Asia that has a thick bark which is not utilized at all. The sorption performance of cork from Quercus cerris bark with four polycyclic aromatic hydrocarbons (PAHs (acenaphthene, fluorene, phenanthrene, and anthracene was investigated. Quercus cerris cork was characterized for elemental analysis, acidic groups, and summative chemical composition, and the results were compared with Quercus suber cork. A Microtox® test was carried out to test for the release of any toxic compounds into the solution. All isotherms fit the Freundlich model and displayed linear n values. Quercus cerris exhibited a high efficiency for sorption of PAHs for the studied concentrations (5 to 50 µg/L with 80-96% removal, while the desorption isotherms showed a very low release of the adsorbed PAHs (<2%. In relation to Quercus suber cork, KF values of Quercus cerris cork are about three times lower. The quantity of Quercus cerris cork required to reduce water pollution by PAHs was estimated to be less than twice the quantity of other adsorbents such as aspen wood and leonardite. Toxicity tests indicated that non-toxic compounds were released into the solution by the Quercus cerris and Quercus suber cork samples. Overall the results indicate the potential use of Quercus cerris cork and of Quercus suber cork as effective and economical biosorbents for the treatment of PAH-contaminated waters.

  5. Efeito da pastorícia tradicional na redução de combustíveis em bosques de Quercus pyrenaica

    OpenAIRE

    Castro, Marina; Castro, José; Gómez Sal, Antonio

    2005-01-01

    Os bosques de Quercus pyrenaica foram no passado e continuam no presente, a ser utilizados por rebanhos de pequenos ruminantes (ovelhas e cabras) explorados em regime extensivo, pelo que são frequentemente considerados sistemas de uso múltiplo. Neste trabalho investiga-se o efeito da pastorícia tradicional na redução da acumulação de biomassa herbácea, pretendendo avaliar o efeito da presença dos animais nestes sistemas. Avaliou-se a biomassa herbácea em bosques de Quercus pyrenaica em doi...

  6. Soil properties and understory herbaceous biomass in forests of three species of Quercus in Northeast Portugal

    Directory of Open Access Journals (Sweden)

    Marina Castro

    2014-12-01

    Full Text Available Aim of study: This paper aims to characterize some soil properties within the first 25 cm of the soil profile and the herbaceous biomass in Quercus forests, and the possible relationships between soil properties and understory standing biomass.Area of study: Three monoespecific Quercus forests (Q. suber L., Q. ilex subsp. rotundifolia Lam. and Q. pyrenaica Willd in NE Portugal.Material and methods: During 1999 and 2000 soil properties (pH-KCl, total soil nitrogen (N, soil organic carbon (SOC, C/N ratio, available phosphorus (P, and available potassium (K and herbaceous biomass production of three forest types: Quercus suber L., Quercus ilex subsp. rotundifolia Lam. and Quercus pyrenaica Willd were studied.Main results: The results showed a different pattern of soil fertility (N, SOC, P, K in Quercus forests in NE of Portugal. The C/N ratio and the herbaceous biomass confirmed this pattern. Research highlights: There is a pattern of Quercus sp. distribution that correlates with different soil characteristics by soil characteristics in NE Portugal. Q. pyrenaica ecosystems were found in more favoured areas (mesic conditions; Q. rotundifolia developed in nutrient-poor soils (oligotrophic conditions; and Q. suber were found in intermediate zones.Keywords: fertility; biomass; C/N ratio; cork oak; holm oak; pyrenean oak.

  7. Biochemistry of Suberization

    Science.gov (United States)

    Dean, Bill B.; Kolattukudy, P. E.

    1977-01-01

    Biosynthesis of the aliphatic components of suberin was studied in suberizing potato (Solanum tuberosum) slices with [1-14C]oleic acid and [1-14C]acetate as precursors. In 4-day aged tissue, [1-14C]oleic acid was incorporated into an insoluble residue, which, upon hydrogenolysis (LiA1H4), released the label into chloroform-soluble products. Radio thin layer and gas chromatographic analyses of these products showed that 14C was contained exclusively in octadecenol and octadecene-1, 18-diol. OsO4 treatment and periodate cleavage of the resulting tetraol showed that the labeled diol was octadec-9-ene-1, 18-diol, the product expected from the two major components of suberin, namely 18-hydroxyoleic acid and the corresponding dicarboxylic acid. Aged potato slices also incorporated [1-14C]acetate into an insoluble material. Hydrogenolysis followed by radio chromatographic analyses of the products showed that 14C was contained in alkanols and alkane-α,ω-diols. In the former fraction, a substantial proportion of the label was contained in aliphatic chains longer than C20, which are known to be common constituents of suberin. In the labeled diol fraction, the major component was octadec-9-ene-1,18-diol, with smaller quantities of saturated C16, C18, C20, C22, and C24-α,ω-diols. Soluble lipids derived from [1-14C]acetate in the aged tissue also contained labeled very long acids from C20 to C28, as well as C22 and C24 alcohols, but no labeled ω-hydroxy acids or dicarboxylic acids were detected. Label was also found in n-alkanes isolated from the soluble lipids, and the distribution of label among them was consistent with the composition of n-alkanes found in the wound periderm of this tissue; C21 and C23 were the major components with lesser amounts of C19 and C25. The amount of 14C incorporated into these bifunctional monomers in 0-, 2-, 4-, 6-, and 8-day aged tissue were 0, 1.5, 2.5, 0.8, and 0.3% of the applied [1-14C]oleic acid, respectively. Incorporation of [1-14C

  8. Identification of new molecules extracted from Quercus suber L. cork.

    Science.gov (United States)

    Coquet, Corinne; Ferré, Elisée; Peyronel, Dominique; Dal Farra, Claude; Farnet, Anne Marie

    2008-11-01

    Various methods of suberin extraction have been used in order to identify monomers of this complex polymer. Pre-extraction of waxes has allowed us to identify for the first time 3-friedelanol as a terpen from cork. Moreover, the wax chemical composition found here varied from previous results since cerin was not identified while friedelin and betulin were. Three fractions were obtained: a polymeric, a monomeric and a low molecular weight fraction, the last of which has never before been described. 2,6-heptanediol was found to be the main compound of this fraction. Furthermore, depolymerisation at room temperature gives the same yields as those obtained at reflux, defining an easier and cheaper methodology.

  9. Airborne Quercus pollen in SW Spain: Identifying favourable conditions for atmospheric transport and potential source areas.

    Science.gov (United States)

    Maya-Manzano, José María; Fernández-Rodríguez, Santiago; Smith, Matt; Tormo-Molina, Rafael; Reynolds, Andrew M; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela; Sadyś, Magdalena

    2016-11-15

    The pollen grains of Quercus spp. (oak trees) are allergenic. This study investigates airborne Quercus pollen in SW Spain with the aim identifying favourable conditions for atmospheric transport and potential sources areas. Two types of Quercus distribution maps were produced. Airborne Quercus pollen concentrations were measured at three sites located in the Extremadura region (SW Spain) for 3 consecutive years. The seasonal occurrence of Quercus pollen in the air was investigated, as well as days with pollen concentrations ≥80Pm(-3). The distance that Quercus pollen can be transported in appreciable numbers was calculated using clusters of back trajectories representing the air mass movement above the source areas (oak woodlands), and by using a state-of-the-art dispersion model. The two main potential sources of Quercus airborne pollen captured in SW Spain are Q. ilex subsp. ballota and Q. suber. The minimum distances between aerobiological stations and Quercus woodlands have been estimated as: 40km (Plasencia), 66km (Don Benito), 62km (Zafra) from the context of this study. Daily mean Quercus pollen concentration can exceed 1,700Pm(-3), levels reached not less than 24 days in a single year. High Quercus pollen concentration were mostly associated with moderate wind speed events (6-10ms(-1)), whereas that a high wind speed (16-20ms(-1)) seems to be associated with low concentrations.

  10. Phenolic compounds and fatty acids from acorns (Quercus spp.), the main dietary constituent of free-ranged Iberian pigs.

    Science.gov (United States)

    Cantos, Emma; Espín, Juan Carlos; López-Bote, Clemente; de la Hoz, Lorenzo; Ordóñez, Juan A; Tomás-Barberán, Francisco A

    2003-10-08

    The aim of the present work was to identify and quantify the phenolic compounds and fatty acids in acorns from Quercus ilex, Quercus rotundifolia, and Quercus suber. The concentration of oleic acid was >63% of total fatty acids in all cases, followed by palmitic and linoleic acids at similar concentrations (12-20%). The concentrations of alpha-tocopherol in Q. rotundifolia, Q. ilex, and Q. suber were 19, 31, and 38 mg/kg of dry matter (DM), respectively, whereas the concentrations of gamma-tocopherol were 113, 66, and 74 mg/kg of DM, respectively. Thirty-two different phenolic compounds were distinguished. All of them were gallic acid derivatives, in the form of either galloyl esters of glucose, combinations of galloyl and hexahydroxydiphenoyl esters of glucose, tergallic O- or C-glucosides, or ellagic acid derivatives. Several tergallic acid C-glucosides were also present in the extracts obtained from Q. suber. Acorns from Q. ilex and Q. rotundifolia showed similar polyphenol patterns mainly with gallic acid-like spectra. Chromatograms of Q. suber showed mainly polyphenols with ellagic acid-like spectra. Valoneic acid dilactone was especially abundant in Q. suber skin. The contribution of skin to the total phenolics of the acorn was relatively small in Q. rotundifolia and Q. ilex but relatively high in Q. suber. Skin extracts from Q. suber, Q. rotundifolia, and Q. ilex showed 1.3, 1.4, and 1.0 antioxidant efficiencies, respectively (compared to that of butylhydroxyanisole). Endosperm extracts showed lower capacity to prevent lipid peroxidation than skin extracts.

  11. Large-scale patterns of Quercus ilex, Quercus suber, and Quercus pyrenaica regeneration in central-western Spain

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Rolo, Víctor; Moreno, Gerardo

    2010-01-01

    ; that there are differences in the abundance of regeneration between three oak species; that oak regeneration is governed mainly by forest management and structure; and that shrubs act as important physical protectors of seedlings and saplings. We analyzed whether densities of oak seedlings and saplings in several size...... classes were related to stand-structure, understory, and physiographic variables potentially affecting regeneration. Data collected at a regional level (1 km × 1 km grid) by the Spanish Forest Inventory were evaluated from 2,816 plots. Results revealed that regeneration failure was common for all size....... Regeneration was positively correlated with tree cover and density, especially of small and medium-sized trees, and negatively correlated with the presence of large trees, indicating that regeneration failure is mostly associated with more open, uniform, and/or aged woodlands. Regeneration densities of Q. ilex...

  12. PITYOPHAGUS QUERCUS REITTER, 1877, A NEW SAPROXYLIC SAP BEETLE FOR THE ITALIAN FAUNA (Coleoptera, Nitidulidae

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    Paolo Audisio

    2011-10-01

    Full Text Available During ecological investigations on saproxylic beetle communities of central Italy (Latium, at Bosco Polverino (a mixed evergreen/deciduous forest fragment dominated by cork oaks, and at Allumiere (a small fragment of beech forest surrounded by turkey oak stands, the authors found three specimens of Pityophagus quercus Reitter, 1877 (Coleoptera, Nitidulidae. These are the first known records of this species in Italy, and the first one in association with an evergreen oak, Quercus suber. This discovery led us to review both bionomical and faunistic data so far available on this exceedingly rare and poorly known species.

  13. First Report of Erannis defoliaria on Quercus sp. in North West of Tunisia

    OpenAIRE

    Yaussra Mannai; Olfa Ezzine; Saïd Nouira; Mohamed Lahbib Ben Jamâa

    2015-01-01

    Erannis defoliaria, a spring-feeding moth, caused severe defoliation during springs 2009 and 2010. Larvae were collected from Quercus suber in northwestern forest of Tunisia: Bellif and Ain El Baya. Caterpillars of E. defoliaria were also observed feeding on Q. canariensis, Q. afares and other shrub species such as Pistacia lentiscus, Erica arborea, and E. multiflora. In this paper, we present a first report of this pest in Tunisia.

  14. ANÁLISE DESCRITIVA QUANTITATIVA DA AGUARDENTE DE CANA DURANTE O ENVELHECIMENTO EM TONEL DE CARVALHO (Quercus alba L.

    Directory of Open Access Journals (Sweden)

    CARDELLO Helena Maria André Bolini

    1998-01-01

    Full Text Available Apesar da importância econômica e social da aguardente de cana brasileira, são ainda muito escassos os estudos sobre sua qualidade sensorial, porém as crescentes exigências do mercado, tem feito crescer a preocupação com a qualidade dessa bebida. A aguardente de cana é muito apreciada por seu aroma e sabor característicos, que podem ainda melhorar pelo envelhecimento em recipientes de madeira. O complexo processo que ocorre durante o envelhecimento depende além de vários fatores, do tipo de madeira empregada, do tempo de maturação e obviamente da qualidade inicial do destilado. A análise descritiva quantitativa, metodologia muito aplicada na caracterização dos atributos sensoriais de alimentos e bebidas, foi utilizada neste trabalho para estudar o perfil sensorial da aguardente de cana, durante o envelhecimento, em toneis de carvalho. Nesse sentido, foram analisadas amostras de aguardente envelhecidas durante zero, 12, 24, 36 e 48 meses em um tonel de carvalho de 200 litros e duas amostras comerciais, sendo uma delas envelhecida. Dezesseis provadores pré-selecionados através de testes triangulares e análise sequencial, geraram pelo método rede (Kelly's Repertory Grid Method, os termos descritores das aguardentes. Após a etapa de treinamento, foram selecionados 10 provadores com base em seu poder de discriminação, repetibilidade e concordância com a equipe no uso de escalas. As amostras foram então apresentadas e avaliadas pelos provadores, em cabines individuais de forma monádica, com quatro repetições. Os resultados obtidos foram submetidos à análise de variância, teste de médias de Tukey e à Análise de Componentes Principais. Os termos descritores escolhidos em consenso pelos membros da equipe sensorial foram: coloração amarela, aroma alcoólico, aroma de madeira, aroma de baunilha, doçura inicial, doçura residual, sabor alcóolico inicial, sabor alcóolico residual, sabor de madeira inicial, sabor de

  15. Utility of ITS sequence data for phylogenetic reconstruction of Italian Quercus spp.

    Science.gov (United States)

    Bellarosa, Rosanna; Simeone, Marco C; Papini, Alessio; Schirone, Bartolomeo

    2005-02-01

    Nuclear ribosomal DNA sequences encoding the 5.8S RNA and the flanking internal transcribed spacers (ITS1 and ITS2) were used to test the phylogenetic relationships within 12 Italian Quercus taxa (Fagaceae). Hypotheses of sequence orthology are tested by detailed inspection of some basic features of oak ITS sequences (i.e., general patterns of conserved domains, thermodynamic stability and predicted conformation of the secondary structure of transcripts) that also allowed more accurate sequence alignment. Analysis of ITS variation supported three monophyletic groups, corresponding to subg. Cerris, Schlerophyllodrys (=Ilex group sensu Nixon) and Quercus, as proposed by Schwarz [Feddes Rep., Sonderbeih. D, 1-200]. A derivation of the "Cerris group" from the "Ilex group" is suggested, with Q. cerris sister to the rest of the "Cerris group." Quercus pubescens was found to be sister to the rest of the "Quercus group." The status of hybrispecies of Q. crenata (Q. cerrisxQ. suber) and Q. morisii (Q. ilexxQ. suber) was evaluated and discussed. Finally, the phylogenetic position of the Italian species in a broader context of the genus is presented. The utility of the ITS marker to assess the molecular systematics of oaks is therefore confirmed. The importance of Italy as a region with a high degree of diversity at the population and genetic level is discussed.

  16. Pattern recognition of acorns from different Quercus species based on oil content and fatty acid profile

    Directory of Open Access Journals (Sweden)

    Abreu, José M.F.

    2003-12-01

    Full Text Available The aim of this study was (i to characterize different species of Quercus genus and (ii to discriminate among them on the basis of the content and fatty acid composition of the oil in their fruits and/or their morphological aspects via pattern recognition techniques (Principal Component Analysis, PCA, Cluster Analysis, CA, and Discriminant Analysis, DA. Quercus rotundifolia Lam., Quercus suber L. and Quercus pyrenaica Willd., grown in the same stand in the centre of Portugal, were investigated. When oil content and respective fatty acid composition were used to characterize samples, well-separated groups corresponding to each of the species were observed by PCA and confirmed by CA and DA. The ‘‘width’’ and ‘‘length’’ of acorns exhibited a low discriminant power. Acorns from Q. rotundifolia showed the highest average oil content followed by Q. suber and Q. pyrenaica acorns (9.1, 5.2 and 3.8%, respectively. Fatty acid profiles of Q. rotundifolia and Q. suber oils are similar to olive oil while the oil from Q. pyrenaica acorns is more unsaturated.El objetivo de este estudio fué (i la caracterización de diferentes especies del género Quercus y (ii la clasificación de las mismas en base al contenido y composición de ácidos grasos del aceite de sus frutos y/o en sus caracteres morfológicos, via técnicas de patrón de reconocimiento (Análisis de Componentes Principales, ACP, Análisis de Cluster, AC, y Análisis Discriminante, AD. Se han estudiado Quercus rotundifolia Lam., Quercus suber L. y Quercus pyrenaica Willd., pertenecientes a la misma zona del centro de Portugal. Al emplear el contenido de aceite y sus respectivas composiciones de ácidos grasos para caracterizar a las muestras, el ACP reveló grupos bien separados correspondientes a cada especie, los cuales, a su vez, se confirmarón con el AC y el AD. El ‘‘ancho’’ y ‘‘longitud’’ de las bellotas

  17. O factor de coberto vegetal, para árvores e Arbustos, em modelos de erosão hídrica The vegetation cover factor, for tree and bush canopies, in models of water erosion

    Directory of Open Access Journals (Sweden)

    Carla Rolo Antunes

    2011-07-01

    Full Text Available O objectivo primordial do presente trabalho consiste na análise do comportamento de cobertos arbóreos e arbustivos, em termos do processo de intercepção da precipitação, designadamente, retenção e gotejo, e no estabelecimento de uma componente a incluir em modelos de erosão, que permita quantificar o factor de coberto vegetal em caso de ocupação do solo por estes cobertos, associados a culturas arvenses, em subcoberto, particularmente, na Equação Universal da Perda de Solo Revista (RUSLE. O trabalho experimental utilizou um simulador de chuva, tendo-se obtido valores do diâmetro das gotas (gotejo das folhas de espécies características dos sistemas de uso do solo mais comuns no Sul de Portugal, nomeadamente sobreiro (Quercus suber L., azinheira (Quercus ilex L. ssp. rotundifolia Lam e carrasco (Quercus coccifera L., e quantificado valores de retenção nas folhas. A partir dos resultados obtidos estimou-se a energia cinética para diferentes alturas de queda e, consequentemente, valores correctivos a aplicar aos valores de C tradicionalmente considerados, relativos às culturas agrícolas.The main objective of this work consists on the analyzes of tree and bush canopies behavior, in terms of the rainfall interception process, namely, leave retention, and dripping, and the establishment of a erosion model component to include in to quantify the cover factor (C of the Revised Universal Soil Loss Equation (RUSLE for mixed land covered systems with arable crops, in association with trees and bushes. In the experimental work a rainfall simulator was used and the characteristic values for the diameter of the dripping drops and retention of the leaves from characteristic species of the more common mixed land-use systems in Southern of Portugal, particularly with Cork oak (Quercus suber L., Holm or evergreen oak (Quercus ilex L. ssp. rotundifolia Lam and Kermes or wild oak (Quercus coccifera L., were obtained. From the obtained results

  18. A cortiça como sonda ambiental de metais pesados: um serviço sócio-ambiental prestado por montados de sobro e sobreirais The cork as environmental probe of heavy metals: a socio- environmental service done by “montados” with cork oaks and cork oak stands (Quercus suber L.

    Directory of Open Access Journals (Sweden)

    J. Ponte-e-Sousa

    2007-01-01

    Full Text Available A longevidade do sobreiro e a capacidade que a cortiça amadia tem de crescer construindo camadas anuais extremamente bem individualizáveis permitiu criar a hipótese de correlação entre as marcas químicas deixadas em cada camada de crescimento e as características ambientais do local onde o sobreiro vegeta. Isto permitiria a construção de séries de novénios de distribuição espacial e temporal da característica que se pretenda estudar. Há nisto algumas semelhanças com abordagens dendrométricas, sendo que estas tendem a ser muito mais agressivas. Foi objectivo deste trabalho que numa fase inicial do estudo se procedesse à criação de uma maneira credível de fazer a quantificação de chumbo (II no felema da cortiça recorrendo a uma técnica de análise química nunca antes utilizada para este efeito – a voltametria. A escolha deste método da análise química moderna resulta do conhecimento das vantagens competitivas que tem sobre outros, quando aquele é aplicável, como se demonstra ser o caso. A metodologia utilizada começou por exigir a recolha de uma porção de cortiça de um sobreiro escolhido ao acaso, de maneira a encontrar o material cortiça como se encontra na árvore. No momento não se consideram possíveis correlações biogeográficas mas tão somente o material propriamente dito. Tendo sido possível fazer a quantificação indicada, estão em curso os estudos necessários à verificação da hipótese que dá o mote a este trabalho de investigação centrado no sobreiro do montado e do sobreiral, sendo que a principal conclusão a retirar é que a possibilidade de utilização do sobreiro como indicador da qualidade ambiental do local, neste caso quanto ao teor em Pb(II, é mais um serviço prestável (pelo ecossistema que orbita em torno do sobreiro às populações humanas da área da bacia mediterrânica ocidental. O futuro uso da voltametria como forma de, determinando a concentração do metal em

  19. Establecimiento de cuatro especies de Quercus en el sur de la Península Ibérica: factores condicionantes

    OpenAIRE

    2010-01-01

    Las especies del género Quercus son muy representativas del estrato arbóreo de los bosques mediterráneos y presentan limitaciones para su regeneración, siendo la fase de plántula muy sensible a las condiciones ambientales (Jordano et al. 2008). En esta tesis se han estudiado algunos de los factores clave para el establecimiento de varias especies de Quercus (Q. ilex ssp ballota, Q. suber, Q. faginea, Q. pyrenaica), abarcando las fases de depredación post-dispersiva, emergencia, crecimiento y ...

  20. Methodology for cork plank characterization (Quercus suber L.) by near-infrared spectroscopy and image analysis

    Science.gov (United States)

    Prades, Cristina; García-Olmo, Juan; Romero-Prieto, Tomás; García de Ceca, José L.; López-Luque, Rafael

    2010-06-01

    The procedures used today to characterize cork plank for the manufacture of cork bottle stoppers continue to be based on a traditional, manual method that is highly subjective. Furthermore, there is no specific legislation regarding cork classification. The objective of this viability study is to assess the potential of near-infrared spectroscopy (NIRS) technology for characterizing cork plank according to the following variables: aspect or visual quality, porosity, moisture and geographical origin. In order to calculate the porosity coefficient, an image analysis program was specifically developed in Visual Basic language for a desktop scanner. A set comprising 170 samples from two geographical areas of Andalusia (Spain) was classified into eight quality classes by visual inspection. Spectra were obtained in the transverse and tangential sections of the cork planks using an NIRSystems 6500 SY II reflectance spectrophotometer. The quantitative calibrations showed cross-validation coefficients of determination of 0.47 for visual quality, 0.69 for porosity and 0.66 for moisture. The results obtained using NIRS technology are promising considering the heterogeneity and variability of a natural product such as cork in spite of the fact that the standard error of cross validation (SECV) in the quantitative analysis is greater than the standard error of laboratory (SEL) for the three variables. The qualitative analysis regarding geographical origin achieved very satisfactory results. Applying these methods in industry will permit quality control procedures to be automated, as well as establishing correlations between the different classification systems currently used in the sector. These methods can be implemented in the cork chain of custody certification and will also provide a certainly more objective tool for assessing the economic value of the product.

  1. Scale-dependent segregation of seeders and resprouters in cork oak (Quercus suber) forests.

    Science.gov (United States)

    Coca, M; Pausas, J G

    2012-02-01

    Recent studies showed that disturbances and water availability determine the richness among plants with different post-fire strategies of Mediterranean-type ecosystems. The aim of this study was to determine whether or not the scale of analysis has an influence on the effects of these factors and, therefore, on the segregation of the dominant post-fire strategies, obligate seeders and obligate resprouters, and facultative species. We recorded all woody species and geographical features on 94 (75 m(2)) plots of cork oak woodlands in the southern Iberian Peninsula. For each regenerative type (resprouters, seeders and species with both traits--facultative species), we tested the relationship between the number of species and the predictors using a generalised linear mixed model. The fixed predictor considered at the large scale was altitude, and fixed predictors considered at the local scale were aspect (north/south) and disturbance (fire and clearing by heavy machinery; yes/no). The random predictor was the factor of site. When this factor did not have significant effect for some regenerative types, these relationships was tested using a generalised linear model. Resprouting species were most represented at lower altitudes and in undisturbed sites, while seeders were also at lower altitudes but mostly on south-facing slopes, especially south-facing disturbed sites. For facultative species, site is the most important variable. The proportion of seeders from the total species is not related to altitude, but it is related to disturbance and aspect. These results suggest that there is no segregation of the richness of seeders and resprouters at the large scale (altitudinal gradient). Differences appeared at the local scale (aspect and disturbance).

  2. Diurnal changes in photoprotective mechanisms in leaves of cork oak (Quercus suber) during summer

    Energy Technology Data Exchange (ETDEWEB)

    Faria, T.; Garcia-Plazaola, J. I.; Cerasoli, S.; Pereira, J. S.; Chaves, M. M. [Instituto Superior de Agronomia, Lisbon (Portugal). Dept. de Engenharia Florestal; Abadia, A.

    1996-01-01

    Diurnal variations in photoprotective mechanisms were studied in sun and shade leaves of 40-year old oak trees during early summer in Portugal. Stomatal conductance, and net carbon assimilation rate of sun leaves was found to be highest in the morning, declined substantially by midday and showed almost no recovery in the afternoon, despite the fact that the trees suffered no severe water deprivation as indicated by high predawn leaf water potential. The high positive linear correlation between photosynthesis and stomatal conductance suggests that stomatal closure is a feature of endogenous metabolic regulation rather than a short-term response to light, temperature or leaf-to-air water pressure deficit, and is the main factor limiting photosynthesis under the experimental conditions. 51 refs., 9 figs.

  3. Identificação do carbamato de etila durante o armazenamento da cachaça em tonel de carvalho (quercus sp e recipiente de vidro

    Directory of Open Access Journals (Sweden)

    Jeancarlo Pereira dos Anjos

    2011-01-01

    Full Text Available The objective of the present study was the identification and quantification of ethyl carbamate (EC, by HPLC-FLD, after different periods of storage in an oak (Quercus sp barrel and a glass vessel. The concentration of EC in the cachaça samples varied from

  4. Diplodia quercivora sp. nov.: a new species of Diplodia found on declining Quercus canariensis trees in Tunisia.

    Science.gov (United States)

    Linaldeddu, Benedetto T; Franceschini, Antonio; Alves, Artur; Phillips, Alan J L

    2013-01-01

    During a study of the species of Botryosphaeriaceae associated with oak decline in Tunisia, a large collection of Diplodia strains were isolated from Quercus afares, Q. canariensis and Q. suber trees showing a progressive dieback of shoots and branches, trunk canker and exudates and collar rot. Most of the isolates were identified as Diplodia corticola, while two isolates from Q. canariensis were morphologically and phylogenetically (ITS and tef1-α sequences data) distinct from all other known species of Diplodia. They are described here as Diplodia quercivora sp. nov. In addition, phylogenetic analyses showed for the first time the existence of two distinct lineages within D. corticola. In artificial inoculation experiments, D. quercivora caused necrotic lesions on bark and wood of three Mediterranean oak species, Q. ilex, Q. pubescens and Q. suber. In particular, among the oak species tested, Q. pubescens was the most susceptible.

  5. Maternal influences on seed mass effect and initial seedling growth in four Quercus species

    Science.gov (United States)

    González-Rodríguez, Victoria; Villar, Rafael; Navarro-Cerrillo, Rafael M.

    2011-01-01

    Seed mass represents the reserves available for growth in the first stages of plant establishment. Variation in seed mass is an important trait which may have consequences for growth and survival of seedlings. Three mechanisms have been proposed to explain how seed mass influences seedling development: the reserve use effect, the metabolic effect and the seedling-size effect. Few studies have evaluated at the same time the three hypotheses within species and none have evaluated the effect of the mother trees. We studied four Quercus species by selecting five mother trees per species. Seeds were sown in a glasshouse and the use of seed reserves, seedling growth and morphology were measured. Considering all mothers of the same species together, we did not find the reserve effect for any species, the metabolic effect was observed in all species except for Quercus suber, and the seedling-size effect was matched for all the species. Within species, maternal origin modified the studied relationships and thus the studied mechanisms as we did not observe seed mass effects on all mothers from each species. Moreover, the metabolic effect was not found in any mother of Quercus ilex and Quercus faginea. We concluded that a maternal effect can change seed mass relationships with traits related to seedling establishment. The conservation of this high intra-specific variability must be considered to guarantee species performance in heterogeneous environments and in particular in the current context of climate change.

  6. y Quercus laurina

    Directory of Open Access Journals (Sweden)

    R. Flores-Velázquez

    2007-01-01

    Full Text Available Se determinaron las características de maquinado con base en la norma ASTM D 1666-87, en las operaciones de cepillado, barrenado, moldurado, torneado y lijado de la madera de Quercus affinis y Quercus laurina. Los mejores resultados de cepillado para Q. affinis se encontraron al combinar el ángulo de corte de 15º y una velocidad de alimentación de 7.5 m·min-1, para Q. laurina no hubo influencia del ángulo de corte. En el barrenado se obtuvieron excelentes resultados con las dos velocidades de giro de broca probadas. Para el moldurado, los resultados para las dos especies fueron excelentes en ambos cortes. En el torneado se encontró que no existe influencia del contenido de humedad para Q. laurina, mientras que para Q. affinis se clasificó como buena para un contenido de humedad menor y excelente para el mayor contenido de humedad. Y para el lijado los resultados fueron excelentes. De acuerdo a los resultados de las pruebas, las dos especies son apropiadas para ser utilizadas por la industria maderera para la elaboración de productos terminados de alta calidad.

  7. Ultrastructure of the suberized styloid crystal cells in Agave leaves.

    Science.gov (United States)

    Wattendorff, J

    1976-01-01

    Styloid calcium oxalate crystal idioblasts of Agave americana L. are suberized. Where the crystals do not touch the cell wall directly they are enclosed in a suberinic sheath which is connected with the suberinic wall layer. No polysaccharides are laid down as a tertiary wall layer, nor could any polysaccharides be found in the crystal sheath. These results contradict those of Arnott (1973) but agree fully with those of Rothert and Zalenski (1899).

  8. Ectomycorrhizal association of three Lactarius species with Carpinus and Quercus trees in a Mexican montane cloud forest.

    Science.gov (United States)

    Lamus, Valentina; Montoya, Leticia; Aguilar, Carlos J; Bandala, Victor M; Ramos, David

    2012-01-01

    Ectomycorrhizal (EM) fungi are being monitored in the Santuario del Bosque de Niebla in the central region of Veracruz (eastern Mexico). Based on the comparison of DNA sequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips, we discovered the EM symbiosis of Lactarius indigo, L. areolatus and L. strigosipes with Carpinus caroliniana, Quercus xalapensis and Quercus spp. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). Descriptions coupled with photographs of ectomycorrhizas and basidiomes are presented.

  9. Permeability of the Suberized Mestome Sheath in Winter Rye 1

    Science.gov (United States)

    Peterson, Carol A.; Griffith, Marilyn; Huner, Norman P. A.

    1985-01-01

    Mestome sheath cells of winter rye (Secale cereale L. cv Puma) deposit suberized lamellae in their secondary cell walls. Histochemical tests including acid digestion and staining with Sudan IV and Chelidonium majus root extract were used to detect the presence of suberin in the primary cell wall. There was no evidence of a Casparian band between adjacent mestome sheath cells. Fluorescent dye techniques were used to trace solute movement through the rye leaf apoplast. Calcofluor white M2R, a fluorescent dye which binds to cell walls as it moves apoplastically, proved to be too limited in its mobility in leaves to test mestome sheath permeability. Trisodium 3-hydroxy-5,8,10 pyrene trisulfonate, a fluorescent dye which is mobile in the apoplast, moved easily up the vascular bundles in the transpiration stream, and diffused outward from the veins to the epidermal cell walls within minutes of reaching a particular level in the leaf. We conclude that the suberized mestome sheath of rye leaves is freely permeable to solutes moving apoplastically through radial primary cell walls. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:16663999

  10. Anti nutritional evaluation of the flour of the nipples of holm oak (quercus ilex) and oak cork (quercus suber) Raw and pressure-sealed

    Energy Technology Data Exchange (ETDEWEB)

    El Mahi, F. Z.

    2009-07-01

    The present study contributes to the development of the food potential of the nipples of oak like new resources likely to be exploited on an industrial scale for their use in animal feeds. Our work relates to two species S of nipples of oak, edible, the homl oak and the other fodder one, the oal cork known for their spontaneousness and their vey significant geographical distribution. (Author)

  11. Fractal dimension does not adequately describe the complexity of leaf margin in seedlings of Quercus species

    Directory of Open Access Journals (Sweden)

    Camarero, Jesús Julio

    2002-06-01

    Full Text Available We quantified the complexity of leaf margin in a set of Quercus tree species using fractal dimension estimated by the box-counting method (FDb. Leaves were sampled from seedlings in a set of 15 Quercus species with a wide range of leaf morphology (Q. agrifolia, Q. alba, Q. cerris, Q. chrysolepis, Q. coccifera, Q.faginea, Q. frainetto, Q. ilex subsp. ballota, Q. ilex subsp. ilex, Q. petraea, Q. pyrenaica, Q. robur, Q. rubra, Q. suber, and Q. velutina. To describe leaf-edge roughness, we used simple indices: P/L - the ratio of leaf perimeter (P to maximum leaf length (L along the main nerve; P/A - the ratio of leaf perimeter to leaf-blade area (A and its dimensionless version (P/A0'; and WM/Wm -the ratio of maximum distance from the lobe tip to the main nerve (WM to minimum distance from the lobe incision to the main nerve (Wm. There was a strong positive relationship between FDb and P/A. Clustering analysis revealed the existence of three groups of leaves, namely those with: smooth or spiny margins (e.g., Q. coccifera, Q. velutina, shallow lobes (e.g., Q. petraea, and deep lobes (e.g., Q. pyrenaica. In the studied Quercus species, the ratio WM/Wm is a simple and suitable leaflobation index. It is suggested that the flux rate along the leaf edge is related to the complexity of this boundary.Se ha cuantificado la complejidad del margen de las hojas de varias especies arboreas del genero Quercus utilizando la dimension fractal estimada mediante el modo del recuento de cajas (FDb. Se tomaron hojas procedentes de plantulas pertenecientes a 15 especies de Quercus con un amplio rango de morfologfa foliar (Q. agrifolia, Q. alba, Q. cerris, Q. chrysolepis, Q. coccifera, Q. faginea, Q. frainetto, Q. ilex subsp. ballota, Q. ilex subsp. ilex, Q. petraea, Q. pyrenaica, Q. robur, Q. rubra, Q. suber y Q. velutina. Se usaron varios Indices sencillos para describir la complejidad del borde de la hoja: P/L, la relation entre el perimetro foliar (P y la longitud

  12. Variability of cork from Portuguese Quercus suber studied by solid-state (13)C-NMR and FTIR spectroscopies.

    Science.gov (United States)

    Lopes, M H; Barros, A S; Pascoal Neto, C; Rutledge, D; Delgadillo, I; Gil, A M

    2001-01-01

    A new approach is presented for the study of the variability of Portuguese reproduction cork using solid-state (13)C-NMR spectroscopy and photoacoustic (PAS) FTIR (FTIR-PAS) spectroscopy combined with chemometrics. Cork samples were collected from 12 different geographical sites, and their (13)C-cross-polarization with magic angle spinning (CP/MAS) and FTIR spectra were registered. A large spectral variability among the cork samples was detected by principal component analysis and found to relate to the suberin and carbohydrate contents. This variability was independent of the sample geographical origin but significantly dependent on the cork quality, thus enabling the distinction of cork samples according to the latter property. The suberin content of the cork samples was predicted using multivariate regression models based on the (13)C-NMR and FTIR spectra of the samples as reported previously. Finally, the relationship between the variability of the (13)C-CP/MAS spectra with that of the FTIR-PAS spectra was studied by outer product analysis. This type of multivariate analysis enabled a clear correlation to be established between the peaks assigned to suberin and carbohydrate in the FTIR spectrum and those appearing in the (13)C-CP/MAS spectra.

  13. Microspore-derived embryos from Quercus suber anthers mimic zygotic embryos and maintain haploidy in long-term anther culture.

    Science.gov (United States)

    Bueno, Maria A; Gomez, Arancha; Sepulveda, Federico; Seguí, José M; Testillano, Pilar S; Manzanera, José A; Risueño, Maria-Carmen

    2003-08-01

    Microspore-derived embryos produced from cork oak anther cultures after long-term incubations (up to 10-12 months) were analysed in order to determine the genetic variability and ploidy level stability, as well as morphology, developmental pattern and cellular organisation. Most of the embryos from long-term anther cultures were haploid (90.7%), corresponding to their microspore origin. The presence of a low percentage of diploid embryos (7.4%) was observed. Microsatellite analysis of haploid embryos, indicated different microspores origins of the same anther. In the diploid embryos, homozygosity for different alleles was detected from anther wall tissues, excluding the possibility of clonal origin. The maintenance of a high proportion of haploid embryos, in long-term anther cultures, is similar in percentage to that reported in embryos originating after 20 days of plating (Bueno et al. 1997). This suggests that no significant alterations in the ploidy level occurred during long incubations (up to 12 months). These results suggest that ploidy changes are rare in this in vitro system, and do not significantly increase during long-term cultures. Microscopical studies of the microspore embryos in various stages revealed a healthy and well developed anatomy with no aberrant or chimeric structures. The general morphology of embryos appearing at different times after plating, looked similar to that of earlier embryos, as well as the zygotic embryos, indicating that they represent high quality material for cork oak breeding.

  14. Unravelling the distinct crystallinity and thermal properties of suberin compounds from Quercus suber and Betula pendula outer barks.

    Science.gov (United States)

    Sousa, Andreia F; Gandini, Alessandro; Caetano, Ana; Maria, Teresa M R; Freire, Carmen S R; Neto, Carlos Pascoal; Silvestre, Armando J D

    2016-12-01

    The main purpose of this study was to investigate the potential of suberin (a naturally occurring aromatic-aliphatic polyester ubiquitous to the vegetable realm) as a renewable source of chemicals and, in particular, to assess their physical properties. A comparison between cork and birch suberin fragments obtained by conventional depolymerisation processes (hydrolysis or methanolysis) is provided, focusing essentially on their thermal and crystallinity properties. It was found that suberin fragments obtained by the hydrolysis depolymerisation of birch had a high degree of crystallinity, as indicated by their thermal analysis and corroborated by the corresponding XRD diffractions, as opposed to hydrolysis-depolymerised cork suberin counterparts, which were essentially amorphous.

  15. Secretome analysis identifies potential virulence factors of Diplodia corticola, a fungal pathogen involved in cork oak (Quercus suber) decline.

    Science.gov (United States)

    Fernandes, Isabel; Alves, Artur; Correia, António; Devreese, Bart; Esteves, Ana Cristina

    2014-01-01

    The characterisation of the secretome of phytopathogenic fungi may contribute to elucidate the molecular mechanisms of pathogenesis. This is particularly relevant for Diplodia corticola, a fungal plant pathogen belonging to the family Botryosphaeriaceae, whose genome remains unsequenced. This phytopathogenic fungus is recognised as one of the most important pathogens of cork oak, being related to the decline of cork oak forests in the Iberian Peninsula. Unfortunately, secretome analysis of filamentous fungi is limited by the low protein concentration and by the presence of many interfering substances, such as polysaccharides, which affect the separation and analysis by 1D and 2D gel electrophoresis. We compared six protein extraction protocols concerning their suitability for further application with proteomic workflows. The protocols involving protein precipitation were the most efficient, with emphasis on TCA-acetone protocol, allowing us to identify the most abundant proteins on the secretome of this plant pathogen. Approximately 60% of the spots detected were identified, all corresponding to extracellular proteins. Most proteins identified were carbohydrate degrading enzymes and proteases that may be related to D. corticola pathogenicity. Although the secretome was assessed in a noninfection environment, potential virulence factors such as the putative glucan-β-glucosidase, neuraminidase, and the putative ferulic acid esterase were identified. The data obtained forms a useful basis for a deeper understanding of the pathogenicity and infection biology of D. corticola. Moreover, it will contribute to the development of proteomics studies on other members of the Botryosphaeriaceae.

  16. Rhodotorula subericola sp. nov., an anamorphic basidiomycetous yeast species isolated from bark of Quercus suber (cork oak).

    Science.gov (United States)

    Belloch, C; Villa-Carvajal, M; Alvarez-Rodríguez, M L; Coque, J J R

    2007-07-01

    Two yeasts strains, Y-31(T) and Y-20B, pertaining to a previously unknown yeast species were isolated from bark of cork oak in Spain. Physiological characterization revealed a pattern of assimilation of carbon and nitrogen compounds compatible with members of the genus Rhodotorula. From sequence analysis of the D1/D2 region of the 26S rRNA gene, Rhodotorula cycloclastica and Rhodotorula philyla were related to the unknown species. Phylogenetic reconstruction based on the D1/D2 region of the 26S rRNA gene showed that the novel species clustered in a branch together with R. cycloclastica. The name Rhodotorula subericola sp. nov. is proposed, with isolate Y-31(T) (=CECT 11976(T)=CBS 10442(T)) the type strain of this novel taxon in the Microbotryum lineage, subclass Microbotryomycetidae, class Urediniomycetes of basidiomycetous yeasts.

  17. Land use practices and ectomycorrhizal fungal communities from oak woodlands dominated by Quercus suber L. considering drought scenarios.

    Science.gov (United States)

    Azul, Anabela Marisa; Sousa, João Paulo; Agerer, Reinhard; Martín, María P; Freitas, Helena

    2010-02-01

    Oak woodlands in the Mediterranean basin have been traditionally converted into agro-silvo-pastoral systems and exemplified sustainable land use in Europe. In Portugal, in line with the trend of other European countries, profound changes in management options during the twentieth century have led to landscape simplification. Landscapes are dynamic and the knowledge of future management planning combining biological conservation and soil productivity is needed, especially under the actual scenarios of drought and increasing evidence of heavy oak mortality. We examined the ectomycorrhizal (ECM) fungal community associated with cork oak in managed oak woodlands (called montado) under different land use practices, during summer. ECM fungal richness and abundance were assessed in 15 stands established in nine montados located in the Alentejo region (southern Portugal), using morphotyping and ITS rDNA analysis. Parameters related to the montados landscape characteristics, land use history over the last 25 years, climatic and edaphic conditions were taken into account. Fifty-five ECM fungal taxa corresponding to the most abundant fungal symbionts were distinguished on cork oak roots. Cenococcum geophilum and the families Russulaceae and Thelephoraceae explained 56% of the whole ECM fungal community; other groups were represented among the community: Cortinariaceae, Boletaceae, Amanita, Genea, Pisolithus, Scleroderma, and Tuber. There were pronounced differences in ECM fungal community structure among the 15 montados stands: C. geophilum was the only species common to all stands, tomentelloid and russuloid species were detected in 87-93% of the stands, Cortinariaceae was detected in 60% of the stands, and the other groups were more unequally distributed. Ordination analysis revealed that ECM fungal richness was positively correlated with the silvo-pastoral exploitation regime and low mortality of cork oak, while ECM fungal abundance was positively correlated with extensive agro-silvo-pastoral exploitation under a traditional 9-year rotation cultivation system and recent soil tillage. The effects of land use on the ECM fungal community and its implications in different scenarios of landscape management options, oak mortality, and global warming are discussed.

  18. Vegetative propagation of Quercus suber L. by somatic embryogenesis. II. Plant regeneration from selected cork oak trees.

    Science.gov (United States)

    Hernández, I; Celestino, C; Alegre, J; Toribio, M

    2003-04-01

    The regeneration of somatic seedlings from selected 100-year-old cork oak trees is reported. The induction of somatic embryogenesis from leaves of epicormic shoots was significantly affected by genotype, harvesting time and their interaction. Leaves from all five selected trees produced somatic embryos when the segments of branches used as sources of epicormic shoots were collected in May. Genotype, but not the level of photosynthetically active radiation, affected the proliferation of the embryogenic lines and the number of detachable embryos that could be obtained from them. Genotype also affected several steps leading to conversion of somatic embryos, from germination to complete acclimatisation of somatic seedlings. Almost 40% of the somatic embryos from all lines germinated, showing coordinated root and shoot growth. Although the mean percentage of recovery for the whole process was low, plants could be regenerated from four of the five trees tested.

  19. Amido resistente em diversas fontes não convencionais de amido

    Directory of Open Access Journals (Sweden)

    C. Fontinha

    2016-02-01

    Full Text Available Amido resistente (AR é aquele que não é digerido no intestino delgado, conduzindo a efeitos benéficos para a saúde, tal como a fibra dietética faz. Procedeu-se à determinação do AR em farinhas e amidos extraídos de duas variedades de castanha (Castanea sativa Mill, Longal e Martainha, da bolota de azinheira (Quercus rotundifolia e da glande do sobreiro (Quercus suber. As farinhas foram obtidas por moenda dos frutos após secagem a diferentes temperaturas, 40º C, 50º C, 60ºC e 70ºC. Posteriormente, procedeu-se ao isolamento dos amidos das farinhas, através da aplicação de dois métodos de extracção: um físico-químico e outro enzimático. Verificou-se que os teores de AR mais elevados foram os apresentados pelas farinhas dos frutos secos a 60ºC, sendo de 46,8%, 36,5%, 39,9% e 43,9%, respectivamente para as castanhas das variedades Longal e Martainha, para a bolota e para a glande. O método de extracção que apresentou valores mais elevados de AR para os amidos extraídos dos diferentes materiais foi o método físico-químico. Tudo indica que a secagem dos frutos a 60ºC e a aplicação do método de extracção do amido pelo processo físico-químico nas farinhas dos frutos secos a esta temperatura são aqueles que melhor preservam a estrutura dos amidos.

  20. The taxonomic status of the Mexican oak Quercus undata (Fagaceae, Quercus, Section Quercus El estatus taxonómico del encino mexicano Quercus undata (Fagaceae, Quercus, Sección Quercus

    Directory of Open Access Journals (Sweden)

    Jeffrey R. Bacon

    2011-12-01

    Full Text Available Quercus undata Trel. (Fagaceae, Quercus, Section Quercus has a complex taxonomic and nomenclatural history. Intensive sampling of oaks at the type locality of Q. undata Trel. in Durango, Mexico and evaluation of herbarium specimens and plants in the field indicate that Q. undata represents variation in Quercus chihuahuensis Trel. in white oak communities where introgressive hybridization among Q. chihuahuensis, Q. grisea Liebm., and a third white oak, Q. arizonica Sarg. made species identification difficult. Endlich's type specimen of Q. undata, as designated by Trelease, was apparently destroyed in bombing raids on Berlin during World War II, and we propose herein as lectotype the Trelease illustration of the type. An epitype is also designated in support of the lectotype, given that some features cannot be critically observed on the illustration. The long peduncles of the specimen illustrated by Trelease indicate a close relation to Q. chihuahuensis.Quercus undata Trel. (Fagaceae, Quercus, Section Quercus tiene una compleja historia taxonómica y de nomenclatura. Un muestreo intensivo de los encinos en la localidad tipo de Q. undata en Durango, México y análisis de ejemplares en herbario y en el campo indican que Q. undata representa variación en Q. chihuahuensis Trel. en los sitios donde la hibridación introgresiva entre Q. chihuahuensis, Q. grisea Liebm., y un tercer encino blanco, Q. arizonica Sarg., dificultan la identificación de especies. El ejemplar tipo designado por Trelease aparentemente fue destruido en el bombardeo de Berlín durante la Segunda Guerra Mundial, por lo que se propone como lectotipo a la ilustración del tipo en la obra de Trelease. Se designa también un epitipo dado que algunos rasgos no pueden ser críticamente observados en la ilustración. Los largos pedúnculos del espécimen ilustrado por Trelease indican la relación cercana a Q. chihuahuensis.

  1. Pb uptake and tolerance in the two selected mangroves with different root lignification and suberization.

    Science.gov (United States)

    Cheng, Hao; Wang, You-Shao; Liu, Yong; Ye, Zhi-Hong; Wu, Mei-Lin; Sun, Cui-Ci

    2015-10-01

    Metal pollution has been widely reported in mangrove wetlands; however, the mechanisms involved in metal detoxification by mangroves are still poorly understood. This study aimed to investigate the possible function of root lignification/suberization on Pb uptake and tolerance in mangroves. Two mangroves, Acanthus ilicifolius and Rhizophora stylosa with different root lignification/suberization were selected as plant materials; the former exhibits a thin exodermis and low lignification/suberization, while the latter possesses a thick exodermis and high lignification/suberization. A pot trial with addition of Pb was conducted to investigate the differences in Pb uptake and tolerance between the two mangroves. The experiment of rhizobox was designed to explore Pb dynamics and availabilities in the rhizosphere soils, besides, the ability of Pb uptake by the excised roots and X-ray analysis for Pb distribution within roots were also detected. The results revealed that R. stylosa exhibited relatively higher Pb tolerance together with less Pb accumulations when compared to A. ilicifolius. For both species, lower proportion of exchangeable and Carbonate Pb and higher higher Fe-Mn oxides Pb were observed in the rhizosphere zone when compared to the respective non-rhizosphere zone. The results from metal uptake by the excised roots and X-ray analysis clearly showed that the thick lignified/suberized exodermis of R. stylosa could more efficiently delay Pb entering into the roots, leading to less Pb accumulation. In summary, the present study proposes a barrier property of the lignified/suberized exodermis in dealing with the stresses of Pb.

  2. Suberization: inhibition by washing and stimulation by abscisic Acid in potato disks and tissue culture.

    Science.gov (United States)

    Soliday, C L; Dean, B B; Kolattukudy, P E

    1978-02-01

    Wounding of potato (Solanum tuberosum L.) tubers results in suberization, apparently triggered by the release of some chemical factor(s) at the cut surface. Suberization, as measured by diffusion resistance of the tissue surface to water vapor, was inhibited by mm concentrations of indoleacetic acid, unaffected by mm concentrations of traumatic acid, severely inhibited at mum concentrations of cytokinin, but stimulated by abscisic acid (ABA) at 10(-4)m. Thorough washing of potato disks up to 3 to 4 days after cutting resulted in severe inhibition of suberization as measured both by diffusion resistance and by the amount of the octadecene diol generated by hydrogenolysis (LiAlH(4)) of the tissue. Disks washed after 4 days did not show any inhibition of suberization. High performance liquid chromatographic analysis of the wash from fresh potato disks showed that about 14 ng of ABA was released into the wash per g of tissue. The amount of ABA released increased with time up to 4 to 6 hours of washing. The maximal amount of ABA was washed out after aging for 24 hours and after 2 days of aging ABA could no longer be found in the surface wash of the disks. Addition of ABA to the media of potato tissue cultures resulted in suberin formation whereas control cultures contained little suberin. The effect of ABA on suberization in the tissue cultures was shown to be linearly concentration-dependent up to 10(-4)m and a linear increase in suberin formation was seen up to about 8 days of culture growth on the media containing 10(-4)m ABA. From these results it is proposed that during the early phase of wound-healing ABA plays a role in triggering a chain of biochemical processes which eventually (in about 3 to 4 days) result in the formation of a suberization-inducing factor, responsible for the induction of the enzymes involved in suberin biosynthesis.

  3. Limitations due to water stress on leaf net photosynthesis of Quercus coccifera in the Portuguese evergreen scrub

    Energy Technology Data Exchange (ETDEWEB)

    Tenhunen, J.D.; Lange, O.L.; Harley, P.C.; Beyschlag, W.; Meyer, A.

    1985-01-01

    Gas exchange characteristics in leaves of the sclerophyll shrub Quercus coccifera were studied in the natural habitat in Portugal during spring and during the summer dry period. Compared to other sclerophyll species growing at the same site, photosynthesis in leaves of Quercus coccifera was less affected by water stress. Moderate water stress after six weeks of drought led to large decreases in stomatal conductance but no change in mesophyll photosynthetic capacity as compared to late spring. Leaf internal CO/sub 2/ pressure remained near 220 ..mu..bar during diurnal courses in the spring. On midsummer days, leaf internal CO/sub 2/ decreased from a late morning value of 200 ..mu..bar to a late afternoon value of approximately 150 ..mu..bar. In contrast to Quercus suber, restriction of CO/sub 2/ supply due to stomatal closure reduced net CO/sub 2/ uptake at midday and in the afternoon during midsummer. A decrease in leaf carboxylation efficiency and an increase in CO/sub 2/ compensation point at midday also played an important role in determining the diurnal course of net photosynthesis. During the late stages of drought in September, severe water stress led to reduction in mesophyll photosynthetic capacity and further reduction in leaf conductance. The observed decrease in mesophyll photosynthetic capacity was correlated with decrease in the daily minimum leaf water potential to greater negative values than -30 bar. At this time, CO/sub 2/ saturated photosynthetic rates decreased as much as 50% over the course of a day when measured at constant saturating light, 32/sup 0/C leaf temperature, and a water vapor mole fraction difference between leaf and air of 30 mbar bar/sup -1/. 24 references, 9 figures.

  4. Perspective on Open-Access Publishing: An Interview with Peter Suber

    Science.gov (United States)

    Cornwell, Reid; Suber, Peter

    2008-01-01

    In this edition of Perspectives, Reid Cornwell discusses open-access publishing with Peter Suber, senior researcher at the Scholarly Publishing and Academic Resources Coalition, senior research professor of philosophy at Earlham College, and currently visiting fellow at Yale Law School. Open access means that scholarly work is freely and openly…

  5. Perspective on Open-Access Publishing: An Interview with Peter Suber

    Science.gov (United States)

    Cornwell, Reid; Suber, Peter

    2008-01-01

    In this edition of Perspectives, Reid Cornwell discusses open-access publishing with Peter Suber, senior researcher at the Scholarly Publishing and Academic Resources Coalition, senior research professor of philosophy at Earlham College, and currently visiting fellow at Yale Law School. Open access means that scholarly work is freely and openly…

  6. Estudio cariológico de Quercus humboldtti Bonpl Caryological study of Quercus humboldtii Bonpl

    Directory of Open Access Journals (Sweden)

    Alvarado de Coral Cecilia

    1989-12-01

    Full Text Available Se comprobó que la especie del roble Ouercus humboldtii Bonpl. tiene 2 n= 24 cromosomas, al igual que la mayoría de las especies estudiadas de Quercus. Utilizando pretratamiento y tinción con orceina lactopropiónica fue posible obtener el cariotipo e ideograma.Using lactopropionic orceine for a previus tintion we obtained the Caryotype and ideogram of Quercus humboldtii Bonpl. and we observed that it has 2 n = 24 chromosomes as most studied species of Quercus do.

  7. The ecosystem of the Yahudia Nature Reserve with emphasis on dynamics of germination and development of Quercus ithaburensis decne

    OpenAIRE

    Kaplan, Y

    1984-01-01

    6 main subjects connected with the ecology of the Yahudia Forest Reserve are discussed in this paper, following a general survey of the history of nature conservation in Israel against the background of the neighbouring countries. We have described the physical and historical background of the Yahudia Forest; the inventory of vertebrates; the inventory of vegetation, analysing composition and mapping; described and researched <em>Quercus ithaburensisem> from various aspects, wit...

  8. Quercus petraea in België

    NARCIS (Netherlands)

    Rompaey, van E.

    1957-01-01

    Naar aanleiding van het artikel over Quercus petraea in het Corr. bl. no. 4 zend ik u hierbij een kopie van de Belgische verspreidingskaart, omdat daar m.i. wel een en ander uit af te leiden is, dat ook Nederland aanbelangt: 1. Bij bet massale verspreidingsgebied ten Z. van de lijn Samber-Maas (de l

  9. Quercus kelloggii Newb., California black oak

    Science.gov (United States)

    P.M. McDonald

    1990-01-01

    California black oak (Quercus kelloggii) exceeds all other California oaks in volume, distribution, and altitudinal range. Yet this deciduous hardwood has had little sustained commercial use and almost no management, even though its wood closely resembles that of its valuable, managed, and heavily used counterpart-northern red oak (...

  10. Rasgos funcionales en el género Quercus: estrategias adquisitivas frente a conservativas en el uso de recursos

    Directory of Open Access Journals (Sweden)

    E. G. de la Riva

    2014-01-01

    Full Text Available Las especies del género Quercus constituyen uno de los grupos más abundantes e importantes de plantas leñosas de la Península Ibérica, estando su distribución determinada por la disponibilidad de agua, el tipo de suelo y la historia del manejo. El conocimiento de la variación de sus características morfo-funcionales puede ayudarnos a comprender el grado de diversificación de las especies del mismo género y los mecanismos que controlan sus patrones de distribución. Los objetivos principales de este estudio son: (i analizar las relaciones existentes entre los diferentes rasgos funcionales dentro del género Quercus y testar cómo se ajustan a las estrategias de captación de recursos; y (ii comprobar si existe coordinación entre los rasgos medidos a nivel de hoja, tallo y raíz. El muestreo se llevó a cabo en Sierra Morena (Córdoba y la Sierra del Aljibe (Cádiz, cuantificándose rasgos funcionales claves a nivel de hoja, tallo, raíz, tamaño de planta y fisiología en cinco especies de Quercus (Q. canariensis, Q. coccifera, Q. faginea, Q. ilex y Q. suber. Los resultados muestran que las diferentes especies de Quercus presentan claros patrones en sus estrategias funcionales que están relacionados con su distribución, encontrando un gradiente desde especies más conservativas en el uso de recursos en condiciones de menor disponibilidad de agua a especies más adquisitivas en zonas más húmedas. A su vez, se aprecia una coordinación entre los patrones de rasgos funcionales encontrados a nivel de hoja, tallo y de raíz que apoya la existencia de un “espectro de economía” a nivel de la planta entera.

  11. Metal (Pb, Zn and Cu) uptake and tolerance by mangroves in relation to root anatomy and lignification/suberization.

    Science.gov (United States)

    Cheng, Hao; Jiang, Zhao-Yu; Liu, Yong; Ye, Zhi-Hong; Wu, Mei-Lin; Sun, Cui-Ci; Sun, Fu-Lin; Fei, Jiao; Wang, You-Shao

    2014-06-01

    Metal pollution has been widely reported in mangrove wetlands; however, the mechanisms involved in metal detoxification by mangroves are still poorly understood. This study aimed to investigate the possible function of root anatomy and lignification/suberization on metal uptake and tolerance in seedlings of six species of mangroves. The results revealed that the three rhizophoraceous species (Bruguiera gymnorrhiza (L.) Poir, Kandelia obovata Sheue, Liu & Yong and Rhizophora stylosa Griff) consistently exhibited higher metal tolerances than the three pioneer species (Aegiceras corniculatum (Linn.) Blanco, Acanthus ilicifolius L. and Avicennia marina (Forsk.) Viern.). Moreover, metal-tolerant species often exhibited a thick exodermis with high lignification and suberization. The tolerance indices of the mangroves were found to be positively correlated with the amounts of lignin and suberin deposition within the exodermal cell walls. The observed metal uptake by the excised roots further illustrated that a lignified/suberized exodermis directly delayed the entry of metals into the roots, and thereby contributed to a higher tolerance to heavy metals. In summary, the present study proposes a barrier property of the lignified/suberized exodermis in dealing with the stresses of heavy metals, such that the mangroves which possessed more extensive lignification/suberization within the exodermis appeared to exhibit higher metal tolerance.

  12. New Secondary Metabolites from Quercus coccifera L.

    Directory of Open Access Journals (Sweden)

    Didem Şöhretoğlu

    2014-07-01

    Full Text Available Three new secondary metabolites kermesoside (1, cocciferoside (2 and (--8-chlorocatechin (3, were isolated from the the stems with barks of Quercus coccifera along with five known phenolic compounds, 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl-propan-1-one (4 and 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl-propan-1-one (5, trans-resveratrol-3-O-β-glucopyranoside (6 lyoniresinol-9-O-β-xylopyranoside (7, lyoniresinol-9-O-β-glucopyranoside (8. The structure elucidation of the isolated compounds was performed by spectroscopic methods (UV, 1D- and 2D- NMR and HR-MS.

  13. The role of forest fire severity on vegetation recovery after 18 years. Implications for forest management of Quercus suber L. in Iberian Peninsula

    NARCIS (Netherlands)

    Francos, Marcos; Úbeda, Xavier; Tort, Joan; Panareda, Josep María; Cerda Bolinches, Artemio

    2016-01-01

    Wildfires are a widespread phenomenon in Mediterranean environments. Wildfires result in different fire severities, and then in contrasting plant cover and floristic composition. This paper analyses the recovery of the vegetation eighteen years after a wildfire in Catalonia. The Pinus pinaster ss

  14. El decaimiento y muerte de Quercus suber provoca cambios en los ciclos de C, N y P en bosques mixtos mediterráneos

    OpenAIRE

    Ávila Castuera, José M.; Gómez Aparicio, Lorena; Ibáñez Moreno, Beatriz; Gallardo Correa, A.

    2013-01-01

    Sesión 03, S.03-4-O.-- Comunicación oral presentada al citado Congreso, celebrado del 6-10, mayo, 2013, en Pamplona-Iruña, España.-- El libro de resúmenes de comunicaciones del XI Congreso Nacional de la AEET, tiene el siguiente Doi: 10.7818/AEET.XICongress.2013

  15. Purification of a new isoform of laccase from a Marasmius quercophilus strain isolated from a cork oak litter (Quercus suber L).

    Science.gov (United States)

    Farnet, A M; Criquet, S; Pocachard, E; Gil, G; Ferre, E

    2002-01-01

    A new isoform of laccase from Marasmius quercophilus is described in this study. The strain of this white-rot fungus was isolated for the first time on a cork oak litter. This isoform exhibited certain common properties of laccases (a molecular weight of 65 Kda, an optimum pH of 6.2 with syringaldazine). But this laccase has also particularly novel features: the best activity measured was observed at high temperatures (80 C) and this isoform was not inhibited with EDTA. Furthermore, this induced laccase was able to transform most of the aromatic compounds tested without the addition of mediators to the reaction mixture, and the transformation of certain chlorophenols (2-chlorophenol and 2,4-dichlorophenol) by a laccase isoform from M. quercophilus is reported here for the first time. We also demonstrate the importance of 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) as a mediator since it allowed veratryl alcohol and p-hydroxybenzoic acid transformation. Moreover, new products of transformation were observed using the combination of ABTS with this isoform of laccase.

  16. Allocation of 14C assimilated in late spring to tissue and biochemical stem components of cork oak (Quercus suber L.) over the seasons.

    Science.gov (United States)

    Aguado, Pedro L; Curt, M Dolores; Pereira, Helena; Fernández, Jesús

    2012-03-01

    Carbon distribution in the stem of 2-year-old cork oak plants was studied by (14)CO(2) pulse labeling in late spring in order to trace the allocation of photoassimilates to tissue and biochemical stem components of cork oak. The fate of (14)C photoassimilated carbon was followed during two periods: the first 72 h (short-term study) and the first 52 weeks (long-term study) after the (14)CO(2) photosynthetic assimilation. The results showed that (14)C allocation to stem tissues was dependent on the time passed since photoassimilation and on the season of the year. In the first 3 h all (14)C was found in the polar extractives. After 3 h, it started to be allocated to other stem fractions. In 1 day, (14)C was allocated mostly to vascular cambium and, to a lesser extent, to primary phloem; no presence of (14)C was recorded for the periderm. However, translocation of (14)C to phellem was observed from 1 week after (14)CO(2) pulse labeling. The phellogen was not completely active in its entire circumference at labeling, unlike the vascular cambium; this was the tissue that accumulated most photoassimilated (14)C at the earliest sampling. The fraction of leaf-assimilated (14)C that was used by the stem peaked at 57% 1 week after (14)CO(2) plant exposure. The time lag between C photoassimilation and suberin accumulation was ∼8 h, but the most active period for suberin accumulation was between 3 and 7 days. Suberin, which represented only 1.77% of the stem weight, acted as a highly effective sink for the carbon photoassimilated in late spring since suberin specific radioactivity was much higher than for any other stem component as early as only 1 week after (14)C plant labeling. This trend was maintained throughout the whole experiment. The examination of microautoradiographs taken over 1 year provided a new method for quantifying xylem growth. Using this approach it was found that there was more secondary xylem growth in late spring than in other times of the year, because the calculated average cell division time was much shorter.

  17. Vegetative propagation of Quercus suber L. by somatic embryogenesis. I. Factors affecting the induction in leaves from mature cork oak trees.

    Science.gov (United States)

    Hernández, I; Celestino, C; Toribio, M

    2003-04-01

    Somatic embryogenesis was induced in expanding leaves from epicormic shoots forced to sprout from segments of branches collected from several hundred-year-old cork oak trees. Following a basic protocol previously defined for leaves taken from seedlings of this species, several factors were studied to improve the response. The induction frequency was significantly higher when the length of exposure to growth regulators was increased from 7 to 30 days. The combined application of NAA and BAP was essential for induction. Although both regulators had a very significant influence, their interaction was not significant, suggesting independent roles. Leaf size had a crucial effect, because beyond a certain threshold, embryogenesis could not be obtained. Embryogenic lines were maintained via repetitive embryogenesis on hormone-free medium for more than 2 years.

  18. QsMYB1 expression is modulated in response to heat and drought stresses and during plant recovery in Quercus suber.

    Science.gov (United States)

    Almeida, Tânia; Pinto, Glória; Correia, Barbara; Santos, Conceição; Gonçalves, Sónia

    2013-12-01

    Cork oak is an economically important forest species showing a great tolerance to high temperatures and shortage of water. However, the mechanisms underlying this plasticity are still poorly understood. Among the stress regulators, transcription factors (TFs) are especially important since they can control a wide range of stress-inducible genes, which make them powerful targets for genetic engineering of stress tolerance. Here we evaluated the influence of increasing temperatures (up to 55 °C) or drought (18% field capacity, FC) on the expression profile of an R2R3-MYB transcription factor of cork oak, the QsMYB1. QsMYB1 was previously identified as being preferentially expressed in cork tissues and as having an associated alternative splicing mechanism, which results in two different transcripts (QsMYB1.1 and QsMYB1.2). Expression analysis by reverse transcription quantitative PCR (RT-qPCR) revealed that increasing temperatures led to a gradual down-regulation of QsMYB1 transcripts with more effect on QsMYB1.1 abundance. On the other hand, under drought condition, expression of QsMYB1 variants, mainly the QsMYB1.2, was transiently up-regulated shortly after the stress imposition. Recovery from each stress has also resulted in a differential response by both QsMYB1 transcripts. Several physiological and biochemical parameters (plant water status, chlorophyll fluorescence, lipid peroxidation and proline content) were determined in order to monitor the plant performance under stress and recovery. In conclusion, this report provides the first evidence that QsMYB1 TF may have a putative function in the regulatory network of cork oak response to heat and drought stresses and during plant recovery.

  19. Magnesium Deficiency Results in Increased Suberization in Endodermis and Hypodermis of Corn Roots 1

    Science.gov (United States)

    Pozuelo, José M.; Espelie, Karl E.; Kolattukudy, P. E.

    1984-01-01

    The composition of the aliphatic components of suberin in the stele and cortex of young corn (Zea mays L.) roots was determined by combined gas-liquid chromatography/mass spectrometry of the LiAlD4 depolymerization products. ω-Hydroxy acids were shown to be the major class of the aliphatic components of both the hypodermal (35%) and endodermal (28%) polymeric materials with the dominant chain length being C24 in the former and C16 in the latter. Nitrobenzene oxidation of the roots generated p-hydroxybenzaldehyde and vanillin with much less syringaldehyde. Electron microscopic examination of the hypodermal and endodermal cell walls from roots of corn plants grown in a Mg2+ -deficient (0.03 millimolar) nutrient solution showed that these walls were more heavily suberized than the analogous walls of roots from plants grown in normal (2 millimolar) Mg2+ levels. Analysis of the LiAlD4 depolymerization products of the suberin polymers from these roots showed that the roots grown in low Mg2+ had 3.5 times as much aliphatic suberin monomers on a weight basis as the roots from plants grown in nutrient with normal Mg2+ levels. Roots from plants grown in Mg2+ -deficient nutrient solution released 3.8 times the amount of aromatic aldehydes upon nitrobenzene oxidation as that released from normal roots. As the degree of Mg2+ deficiency of the nutrient solution was increased, there was an increase in the aliphatic and aromatic components characteristic of suberin. Thus, both ultrastructural and chemical evidence strongly suggested that Mg2+ deficiency resulted in increased suberization of the cell walls of both hypodermis and endodermis of Zea mays roots. The roots from Mg2+ -deficient plants also had a higher amount of peroxidase activity when compared to control roots. Images Fig. 1-3 PMID:16663407

  20. The composite water and solute transport of barley (Hordeum vulgare) roots: effect of suberized barriers.

    Science.gov (United States)

    Ranathunge, Kosala; Kim, Yangmin X; Wassmann, Friedrich; Kreszies, Tino; Zeisler, Viktoria; Schreiber, Lukas

    2017-03-01

    Roots have complex anatomical structures, and certain localized cell layers develop suberized apoplastic barriers. The size and tightness of these barriers depend on the growth conditions and on the age of the root. Such complex anatomical structures result in a composite water and solute transport in roots. Development of apoplastic barriers along barley seminal roots was detected using various staining methods, and the suberin amounts in the apical and basal zones were analysed using gas chromatography-mass spectometry (GC-MS). The hydraulic conductivity of roots ( Lp r ) and of cortical cells ( Lp c ) was measured using root and cell pressure probes. When grown in hydroponics, barley roots did not form an exodermis, even at their basal zones. However, they developed an endodermis. Endodermal Casparian bands first appeared as 'dots' as early as at 20 mm from the apex, whereas a patchy suberin lamellae appeared at 60 mm. The endodermal suberin accounted for the total suberin of the roots. The absolute amount in the basal zone was significantly higher than in the apical zone, which was inversely proportional to the Lp r . Comparison of Lp r and Lp c suggested that cell to cell pathways dominate for water transport in roots. However, the calculation of Lp r from Lp c showed that at least 26 % of water transport occurs through the apoplast. Roots had different solute permeabilities ( P sr ) and reflection coefficients ( σ sr ) for the solutes used. The σ sr was below unity for the solutes, which have virtually zero permeability for semi-permeable membranes. Suberized endodermis significantly reduces Lp r of seminal roots. The water and solute transport across barley roots is composite in nature and they do not behave like ideal osmometers. The composite transport model should be extended by adding components arranged in series (cortex, endodermis) in addition to the currently included components arranged in parallel (apoplastic, cell to cell pathways).

  1. TOLERANCIA AL FUEGO EN Quercus magnoliifolia1

    Directory of Open Access Journals (Sweden)

    Miguel Ángel López Moctezuma

    2015-06-01

    Full Text Available RESUMENCon el objetivo de conocer la respuesta de Quercus magnoliifolia al fuego en mortalidad y rebrotación, se aplicó una quema prescrita intensa, en fajas a favor de viento y pendiente, a una parcela de 0.5 ha en el estado de Guerrero, México, en abril de 2009. La quema inició a las 10:20 y duró 1 h 26 min. Se midieron las variables meteorológicas temperatura (25-28 °C, humedad relativa (33-24%, y velocidad del viento (7-25 km/h; y de comportamiento del fuego (largo de llama, de 0.5 a 3 m.Seis meses después se midieron variables de la estructura del arbolado y de severidad de la quema. El análisis de datos involucró regresión logarítmica y regresión logística. Los valores estructurales medios fueron: altura (11.2 m, diámetro normal (12. 2 cm y altura de copas (6.8 m. Se halló relación logarítmica directa entre el largo de llama y la velocidad del viento (R2=0.65. No hubo mortalidad producto de la quema, pero 33 % de los árboles rebrotaron. Las variables explicativas de la probabilidad de rebrotación fueron: altura (p=0.0159, diámetro normal (p=0.0394y altura a la base de copas (p=0.0487. La cicatriz sobre el tronco alcanzó 2.6 m y el chamuscado de copas 62 %, en promedio. La especie muestra resistencia a fuego poco severo, gracias a su corteza, y tolerancia a fuego más severo. Las quemas prescritas contribuirían a reducir impactos negativos de incendios en el arbolado.

  2. Bioclimatic characteristic of oak species Quercus macranthera subsp. syspirensis and Quercus petraea subsp. pinnatiloba in Turkey.

    Science.gov (United States)

    Kargioglu, Mustafa; Serteser, Ahmet; Senkul, Cetin; Konuk, Muhsin

    2011-01-01

    This study was carried out to determine some bioclimatic characteristics such as humidity category (Q2), winter variant (m), the length of the dry season (LDS) and the dry season water deficit (DSWD) of naturally growing two endemic oak taxa, Quercus macranthera subsp. syspirensis and Q. petraea subsp. pinnatiloba, living in Turkey. Our findings showed that bioclimatic tolerance range of Q. macranthera subsp. syspirensis possess 7 different types of Mediterranean bioclimate while Q. petraea subsp. pinnatiloba had 8 of them. Although Q. macranthera subsp. syspirensis was ranging among the semiarid, freezing and very cold, Q. petraea subsp. pinnatiloba was among sub-humid, freezing and very cold ambient. It was briefly established that Q. macranthera subsp. syspirensis prefers semi-arid and very cold/freezing conditions and Q. petraea subsp. pinnatiloba prefers sub-humid and cold/very cold climatic conditions.

  3. Tree bark suber-included particles: A long-term accumulation site for elements of atmospheric origin

    Science.gov (United States)

    Catinon, Mickaël; Ayrault, Sophie; Spadini, Lorenzo; Boudouma, Omar; Asta, Juliette; Tissut, Michel; Ravanel, Patrick

    2011-02-01

    The deposition of atmospheric elements on and into the bark of 4-year-old Fraxinus excelsior L. was studied. The elemental composition of the suber tissue was established through ICP-MS analysis and the presence of solid mineral particles included in this suber was established and described through SEM-EDX. Fractionation of the suber elements mixture was obtained after ashing at 550 °C through successive water (C fraction) and HNO 3 2 M (D fraction) extraction, leading to an insoluble residue mainly composed of the solid mineral particles (E fraction). The triplicated % weight of C, D and E were respectively 34.4 ± 2.7, 64.8 ± 2.7 and 0.8 ± 0.1% of the suber ashes weight. The main component of C was K, of D was Ca. Noticeable amounts of Mg were also observed in D. The E fraction, composed of insoluble particles, was mostly constituted of geogenic products, with elements such as Si, Al, K, Mg, representing primary minerals. E also contained Ca 3(PO 4) 2 and concentrated the main part of Pb and Fe. Moreover, The SEM-EDX analysis evidenced that this fraction also concentrated several types of fly ashes of industrial origin. The study of the distribution between C, D and E was analysed through ICP-MS with respect to their origin. The origin of the elements found in such bark was either geogenic (clay, micas, quartz…), anthropogenic or biogenic (for instance large amounts of solid Ca organic salts having a storage role). As opposed to the E fraction, the C fraction, mainly composed of highly soluble K+ is characteristic of a biological pool of plant origin. In fraction D, the very high amount of Ca++ corresponds to two different origins: biological or acid soluble minerals such as calcite. Furthermore, the D fraction contains the most part of pollutants of anthropic origin such as Zn, Cu, Ni, Co, Cd. As a whole, the fractionation procedure of the suber samples allows to separate elements as a function of their origin but also gives valuable information on

  4. A discrimination between Quercus robur L. and Q. petraea

    NARCIS (Netherlands)

    Bakker, E.G.; Dam, van B.C.; Eck, van H.J.; Jacobsen, E.

    2001-01-01

    In natural populations, Quercus robur L. and Q. petraea (Matt.) Liebl. comprise a morphological continuum due to hybridization and/or an overlap in variation between the two species. In order to obtain diagnostic markers to investigate these morphological intermediate forms, leaf morphology and AFLP

  5. In vitro propagation of northern red oak (Quercus rubra L.)

    Science.gov (United States)

    G. Vengadesan; Paula M. Pijut

    2009-01-01

    In vitro propagation of northern red oak (Quercus rubra) shoots was successful from cotyledonary node explants excised from 8-wk-old in vitro grown seedlings. Initially, four shoots per explant were obtained on Murashige and Skoog (MS) medium supplemented with 4.4 µM 6-benzylaminopurine (BA), 0.45 ...

  6. A new cycloartane nortriterpenoid from Quercus variabilis Blume

    Institute of Scientific and Technical Information of China (English)

    Yan Xin; Ling Yun Jia; Jiu Zhi Yuan; Qi Shi Sun

    2009-01-01

    The leaves and stems of Quercus variabilis Blume afforded a new cycloartane nortriterpenoid, 3α-acetyloxy-4α, 14α-dimethyl9β, 19-cycloergost-24-oic acid (1), along with five known compounds (2-6). The structure of I was elucidated by 1D and 2D NMR and mass spectroscopy.

  7. Ellagitannins and complex tannins from Quercus petraea bark.

    Science.gov (United States)

    König, M; Scholz, E; Hartmann, R; Lehmann, W; Rimpler, H

    1994-10-01

    The ellagitannins 2,3-(S)-hexahydroxydiphenoyl-glucose, pedunculagin, vescalagin, and castalagin; the flavanoellagitannins acutissimin A, acutissimin B, eugenigrandin A, guajavin B, and stenophyllanin C; and the procyanidinoellagitannin mongolicanin have been isolated from the bark of Quercus petraea. The ellagitannin fraction had a weak antisecretory effect.

  8. Interspecific variation in functional traits of oak seedlings (Quercus ilex, Quercus trojana, Quercus virgiliana) grown under artificial drought and fire conditions.

    Science.gov (United States)

    Chiatante, D; Tognetti, R; Scippa, G S; Congiu, T; Baesso, B; Terzaghi, M; Montagnoli, A

    2015-07-01

    To face summer drought and wildfire in Mediterranean-type ecosystems, plants adopt different strategies that involve considerable rearrangements of biomass allocation and physiological activity. This paper analyses morphological and physiological traits in seedlings of three oak species (Quercus ilex, Quercus trojana and Quercus virgiliana) co-occurring under natural conditions. The aim of this study was to evaluate species-specific characteristics and the response of these oak seedlings to drought stress and fire treatment. Seedlings were kept in a growth chamber that mimicked natural environmental conditions. All three species showed a good degree of tolerance to drought and fire treatments. Differences in specific biomass allocation patterns and physiological traits resulted in phenotypic differences between species. In Q. ilex, drought tolerance depended upon adjustment of the allocation pattern. Q. trojana seedlings undergoing mild to severe drought presented a higher photosystem II (PSII) efficiency than control seedlings. Moreover, Q. trojana showed a very large root system, which corresponded to higher soil area exploitation, and bigger leaf midrib vascular bundles than the other two species. Morphological and physiological performances indicated Q. trojana as the most tolerant to drought and fire. These characteristics contribute to a high recruitment potential of Q. trojana seedlings, which might be the reason for the dominance of this species under natural conditions. Drought increase as a result of climate change is expected to favour Q. trojana, leading to an increase in its spatial distribution.

  9. Disuccinimidyl suberate cross-linked hemoglobin as a novel red blood cell substitute

    Institute of Scientific and Technical Information of China (English)

    LU; Xiuling; ZHENG; Chunyang; XU; Yuhong; SU; Zhiguo

    2005-01-01

    Disuccinimidyl suberate (DSS) intramolecularly cross-linked hemoglobin (Hb) was developed as a novel red blood cell substitute. A multi-angle laser light scattering detector coupled with size exclusion HPLC was applied to determine the molecular weight of the modified Hb. SDS-PAGE was also used as a complement. It was proved that 83.8% of the product was intramolecularly cross-linked Hb with weight-average molecular weights (Mw) of 67.5 kD, 12% was dimeric Hb with Mw of 146.6 kD, and 4.2% was trimeric Hb with Mw of 306.4 kD. The tetramer structure of the cross-linked Hb was stable as shown in size-exclusion chromatography using a mobile phase containing 1 mol/L MgCl2. Analysis by LC-MS demonstrated that the reaction of DSS with Hb mainly took place between the twoα subunits within a Hb molecule, resulting in stabilization of the tetramer structure. However, the cross-linking was not site-specific. The P50 of the cross-linked Hb decreased from 21.8 mmHg to 14.3 mmHg, and the Hill coefficient decreased from 2.22 to 1.41. Result of isoelectric focusing showed that the pI of DSS cross-linked Hb was in the range of 4.6-5.2, similar to that of serum albumin. The safety of DSS cross-linked Hb was favored by animal tests on rats and guinea pigs. Exchange transfusion experiment with DSS cross-linked Hb using rats as a model indicated no pressor effect or other significant side effects. The characteristics and properties of DSS cross-linked Hb were also compared with that of diaspirin cross-linked Hb reported in the literature.

  10. Effects of desiccation on temperate recalcitrant seeds: differential scanning calorimetry, gas chromatography, electron microscopy, and moisture studies on Quercus nigra and Quercus alba

    Science.gov (United States)

    K.F. Connor; F.T. Bonner; J.A Vozzo

    1996-01-01

    Investigations into the nature of desiccation-sensitive, or recalcitrant, seed behavior have as yet failed to identify exact causes of this phenomenon. Experiments with Quercus nigra L. and Quercus alba L. were conducted to examine physiological and biochemical changes brought about by seed desiccation and to determine if there...

  11. Morphological Response of Eight Quercus Species to Simulated Wind Load.

    Science.gov (United States)

    Wu, Tonggui; Zhang, Peng; Zhang, Lei; Wang, Geoff G; Yu, Mukui

    Leaf shape, including leaf size, leaf dissection index (LDI), and venation distribution, strongly impacts leaf physiology and the forces of momentum exerted on leaves or the canopy under windy conditions. Yet, little has been known about how leaf shape affects the morphological response of trees to wind load. We studied eight Quercus species, with different leaf shapes, to determine the morphological response to simulated wind load. Quercus trees with long elliptical leaves, were significantly affected by wind load (Pwind load, such as bigger leaf thickness, larger stem diameter, allocation to root biomass, and smaller stem height (Pwind can reduce drag and increase the mechanical strength of the tree. Leaf dissection index (LDI), an important index of leaf shape, was correlated with morphological response to wind load (Pwind load.

  12. Morphological Response of Eight Quercus Species to Simulated Wind Load

    Science.gov (United States)

    Zhang, Peng; Zhang, Lei; Wang, Geoff G.; Yu, Mukui

    2016-01-01

    Leaf shape, including leaf size, leaf dissection index (LDI), and venation distribution, strongly impacts leaf physiology and the forces of momentum exerted on leaves or the canopy under windy conditions. Yet, little has been known about how leaf shape affects the morphological response of trees to wind load. We studied eight Quercus species, with different leaf shapes, to determine the morphological response to simulated wind load. Quercus trees with long elliptical leaves, were significantly affected by wind load (PSLA), stem base diameter and stem height under windy conditions when compared to the control. The Quercus trees with leaves characterized by lanceolate or sinuous edges, showed positive morphological responses to wind load, such as bigger leaf thickness, larger stem diameter, allocation to root biomass, and smaller stem height (PSLA, in stem base diameter and in allocation to root biomass. These results suggest that trees with higher LDI, such as those with more and/or deeper lobes, are better adapted to wind load. PMID:27662594

  13. Adaptive and plastic responses of <em>Quercus petraeaem> populations to climate across Europe

    DEFF Research Database (Denmark)

    Sáenz-Romero, Cuauhtémoc; Lamy, Jean-Baptiste; Ducousso, Alexis

    2017-01-01

    of differential population responses to climate (genetic differentiation due to past divergent climatic selection vs. plastic responses to ongoing climate change) and (ii) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled...... for contemporary climate and then projected using data from four regional climate models for years 2071–2100, using two greenhouse gas concentration trajectory scenarios each. Overall, results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual.......5) predicted minor decreases in height and survival, while the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other nonmarginal populations with continental climates were predicted to be severely...

  14. Intrapopulation and Interpopulation Genetic Variation of<em>Quercus in Denmark em>in Denmark

    DEFF Research Database (Denmark)

    Siegismund, Hans Redlef; Jensen, Jan Svejgaard

    2001-01-01

    -Weinberg proportions, suggesting a low level of inbreeding. The differentiation of the Q. petraea and Q. robur populations was quanti. ed with Wright's F-statistics. The within-species component was populations was quanti. ed with Wright's -statistics. The within-species component was low, 0.022, re¿ ecting the wind-pollinated...

  15. Dynamics of Long-lived Foundation Species: The History of Quercus in Southern Scandinavia

    OpenAIRE

    Foster, David Russell; Lindbladh, Matts

    2010-01-01

    (1) The long-term history of Quercus in southern Scandinavia has received little attention despite its important role in modern conservation. In this study the 4000-year dynamics of Quercus, its habitat and other important taxa were analysed with pollen data from 25 small hollows and 6 regional sites across southern Scandinavia. The aim was to provide a context for understanding the species’ current status and managing its future dynamics. (2) The results indicate that Quercus is much less ab...

  16. [Effects of simulating acid rain on photosynthesis and chlorophyll fluorescence parameters of Quercus glauca Quercus glauca].

    Science.gov (United States)

    Wang, Sai; Yi, Li-Ta; Yu, Shu-Quan; Zhang, Chao; Shi, Jing-Jing

    2014-08-01

    At three levels of simulated acid rainfall intensities with pH values of 2.5 (severe), 40 (medium) and 5.6 (light) respectively, the responses of chlorophyll fluorescence and photosynthetic parameters of Quercus glauca seedlings were studied in three acid rainfall treatments, i. e. only the aboveground of seedlings exposed to acid rain (T1), both of the seedlings and soil exposed to acid rain (T2), only the soil exposed to acid rain (T3) compared with blank control (CK). Under the severe acid rainfall, T1 significantly inhibited chlorophyll synthesis, and thus reduced the primary photochemical efficiency of PS II ( F(v)/F(m)), potential activity of PS II (F(v)/F(o)) , apparent quantum (Y), net photosynthetic rate (P(n)), and transpiration rate (T(r)), but increased the light compensation point (LCP) and dark respiration rate (R(d)) of Q. glauca seedlings. T2 inhibited, but T3 played a little enhancement on the aforementioned parameters of Q. glauca seedlings. Under the conditions of medium and light acid rainfall intensities, the above parameters in the three treatments were higher than that of CK, except with lower R(d). The chlorophyll fluorescence and photosynthetic parameters showed a similar tendency in the three treatments, i. e. T2>T3 >T1. It indicated that T1 had the strongest inhibition on seedlings in condition of the severe acid rainfall, while T2 had the most dramatic facilitating effect on seedlings under the medium and light acid rainfall. Intensity of acid rainfall had significant influences on SPAD, F(v)/F(m), F(v)/F(o), Y, P(n), T(r), and maximum photosynthetic rate (A(max)), whereas treatments of acid rainfall affected SPAD, F(v)/F(m), Y, P(n), T(r), A(max) and light saturation point (LSP). The interaction of acid rainfall intensities and treatments played significant effects on SPAD, F(v)/F(m), Y, P(n) and A(max).

  17. The Quercus feeding Stigmella species of the West Palaearctic: new species, key and distribution (Lepidoptera: Nepticulidae)

    NARCIS (Netherlands)

    Nieukerken, van E.J.; Johansson, R.

    2003-01-01

    The species of the Stigmella ruficapitella group occurring in the Western Palaearctic and feeding on Quercus are reviewed. We recognise 19 species, five of which are described as new: Stigmella fasciata sp. n. on Quercus pubescens from Slovenia, Croatia, Greece and Turkey, S. cocciferae sp. n. on Q.

  18. STANDARDIZATION AND CONTAMINATION STUDIES ON NUTGALLS OF QUERCUS INFECTORIA OLIVIER

    Directory of Open Access Journals (Sweden)

    Asif M

    2012-08-01

    Full Text Available Drug consists of nutgalls of Quercus infectoria (Family-Fagaceae, commonly known as “Mazuphal”. Standardization parameters like, physical constants, ash content, solvent residues, phytochemical screening, fluorescence and microscopical analysis were carried out for the quality, strength and purity of the drug. The present work is an also attempt to evaluate contamination parameters for safety of an herbal drug Quercus infectoria such as microbial contamination, aflatoxins, pesticide residues and heavy metals. Result revealed that the total ash content and acid insoluble siliceous matter were found 2.11% and 0.22% respectively in the drug. The extractive values were varies at different solvent at different condition. Loss on drying and pH at 25(ºC were 9.97 and 6.1 respectively. Study revealed that total bacterial count and total fungal count were found to be within the permissible limit. Heavy metal like cadmium and mercury were not detected in the drug but arsenic (0.31 mg/kg and lead (0.70 mg/kg were found under permissible limit. Pesticide residue such as o, p- DDD, p, p- DDD, o p- DDE, p, p- DDE, o, p- DDT, p, p- DDT, α- Endosulfan, β – Endosulfan, Parathion, α- HCH, β- HCH, γ- HCH, δ- HCH was absent in the nutgalls.

  19. Myxomycetes from the bark of the evergreen oak Quercus ilex

    Directory of Open Access Journals (Sweden)

    Wrigley de Basanta, Diana

    1998-06-01

    Full Text Available The results of 81 moist chamber cultures of bark from living Quercus ilex trees are reponed. A total of 37 taxa are cited, extending the number of species found on this substrate to 55. The presence of Licea deplanata on the Iberian Península is confirmed. Seven new records are included for the province of Madrid. Some data are contributed on species frequency and incubation times.Se presentan los resultados de 81 cultivos en cámara húmeda de corteza de Quercus ilex vivo. Se citan 37 táxones, que amplían a 55 el número de especies de mixomicetes encontrados sobre este sustrato. Se confirma la presencia en la Península Ibérica de Licea deplanata, y se incluyen siete nuevas citas para la provincia de Madrid. Se aportan datos sobre frecuencia de aparición y tiempos de incubación de algunas especies.

  20. Vulnerability of Quercus ilex facing increasing drought: which functional adjustments?

    Science.gov (United States)

    Limousin, Jean-Marc; Rambal, Serge; Misson, Laurent; Ourcival, Jean-Marc; Rocheteau, Alain; Rodriguez, Raquel

    2010-05-01

    In the Mediterranean basin, precipitation is expected to decline as a consequence of climate change, and so will induce summer drought duration and intensity increase. The responses of a Quercus ilex coppice to such a decline in water availability were studied for several years within a throughfall exclusion experiment. This study focuses on the ecophysiological and morphological responses that modify transpiration and productivity. The main mechanisms regulating transpiration under decreasing water availability were assessed: stomatal control, twig and stem hydraulic conductance and leaf area adjustment. The decline of transpiration due to the reduced water availability was mainly driven by a reduced leaf area. In the meantime, other hydraulic traits were not significantly modified by the increased drought severity. The phenotypic plasticity of Quercus ilex leaves yielded some modifications of leaf traits, but with slight concurrent consequences on leaf photosynthesis. The decreased water availability reduced carbon assimilation and, in turn, the primary growth and the starch storage of trees. Finally, none of the several adjustments to the long-term experimentally increased drought was observed to reduce the individual vulnerability to water stress.

  1. Allozymes Genetic Diversity of Quercus mongolica Fisch in China

    Institute of Scientific and Technical Information of China (English)

    LI Wenying; GU Wanchun

    2006-01-01

    A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China.Eleven of 21 loci from 13 enzymes assayed were polymorphic.Q.mongolica maintained low level of genetic variation compared with the average Quercus species.At the species level,: the mean number of alleles per locus (A) was 1.905, the percentage of polymorphic loci (P) was 52.38%, the observed heterozygosity (He) was 0.092 and the expected heterozygosity (He) was 0.099.At the population level, the estimates were A =1.421, P =28.976%, Ho= 0.088, He =0.085.Genetic differentiation (Gst was high among populations, it was 0.107.According to the UPGMA cluster analysis based on the genetic distance, 4 populations located in northeast and 2 populations in southwest of the geographical distribution are classified into 2 subgroups, but there was no clear relationship between genetic distance and geographic distance among populations.The low level of genetic diversity of Q.mongolica might be related to the long-term exploitation as economic tree species in history are comparatively seriously disturbed and damaged by human beings, and most of the existing stands are secondary forests.

  2. Sulla presenza di <em>Sorex antinoriiem>, <em>Neomys anomalusem> (Insectivora, Soricidae e <em>Talpa caecaem> (Insectivora, Talpidae in Umbria

    Directory of Open Access Journals (Sweden)

    A.M. Paci

    2003-10-01

    Full Text Available Lo scopo del contributo è di fornire un aggiornamento sulla presenza del Toporagno del Vallese <em>Sorex antinoriiem>, del Toporagno acquatico di Miller <em>Neomys anomalusem> e della Talpa cieca <em>Talpa caecaem> in Umbria, dove le specie risultano accertate ormai da qualche anno. A tal fine sono stati rivisitati i reperti collezionati e la bibliografia conosciuta. Toporagno del Vallese: elevato di recente a livello di specie da Brünner et al. (2002, altrimenti considerato sottospecie del Toporagno comune (<em>S. araneus antinoriiem>. È conservato uno di tre crani incompleti (mancano mandibole ed incisivi superiori al momento prudenzialmente riferiti a <em>Sorex> cfr. <em>antinorii>, provenienti dall?Appennino umbro-marchigiano settentrionale (dintorni di Scalocchio - PG, 590 m. s.l.m. e determinati sulla base della pigmentazione rossa degli ipoconi del M1 e M2; Toporagno acquatico di Miller: tre crani (Breda in Paci e Romano op. cit. e un esemplare intero (Paci, ined. sono stati trovati a pochi chilometri di distanza gli uni dall?altro tra i comuni di Assisi e Valfabbrica, in ambienti mediocollinari limitrofi al Parco Regionale del M.te Subasio (Perugia. In provincia di Terni la specie viene segnalata da Isotti (op. cit. per i dintorni di Orvieto. Talpa cieca: sono noti una femmina e un maschio raccolti nel comune di Pietralunga (PG, rispettivamente in una conifereta a <em>Pinus nigraem> (m. 630 s.l.m. e nelle vicinanze di un bosco misto collinare a prevalenza di <em>Quercus cerrisem> (m. 640 s.l.m.. Recentemente un terzo individuo è stato rinvenuto nel comune di Sigillo (PG, all?interno del Parco Regionale di M.te Cucco, sul margine di una faggeta a 1100 m s.l.m. In entrambi i casi l?areale della specie è risultato parapatrico con quello di <em>Talpa europaeaem>.

  3. Evergreen sclerophyllous Quercus forests in northwestern Yunnan, China as compared to the Mediterranean evergreen Quercus forests in California, USA and northeastern Spain

    Directory of Open Access Journals (Sweden)

    C. Q. Tang

    2006-12-01

    Full Text Available Evergreen sclerophyllous Quercus forests in NW Yunnan (China were studied and compared with the Mediterranean evergreen sclerophyllous Quercus forests in central coastal California (USA and Catalonia (NE Spain. Forests of Q. aquifolioides, Q. pannosa, Q. longispica of NW Yunnan, Q. agrifolia of California and Q. ilex of NE Spain were analyzed as representative communities. The similarities and differences at the community level in the contemporary vegetation of the sclerophyllous Quercus forest found in the three regions are clarified. The general patterns of the evergreen Quercus forest in the three regions were similar, though different assemblages of species were involved. The species diversity in all three regions was rather low. The species richness did not significantly differ among the forests, although in the Q. longispica forest it is somewhat higher than the others. The three representative species of evergreen Quercus in NW Yunnan reached the greatest maximum height, while Q. agrifolia of California had the largest basal area per ha. The Q. ilex forest of Spain had the lowest values for maximum tree height and dbh and the highest density per ha. Frequency of dbh size classes indicated that Q. aquifolioides, Q. pannosa, and Q. agrifolia had potentially good regeneration of the sporadic type with highest values for the intermediate size classes, and the regeneration of Q. longispica and Q. ilex was strong as indicated by a reverse-J pattern. Still, in each area, most regeneration was from sprouting. In all three regions the evergreen Quercus species have adapted to environmental changes, for instance by development of sprouting and rooting abilities to resist drought, cold conditions and various disturbances. The evergreen Quercus forests in NW Yunnan were structurally more similar to the Q. agrifolia forest of central coastal California than to the Q. ilex forest of NE Spain.

  4. Catalytic Rapid Pyrolysis of Quercus variabilis over Nanoporous Catalysts

    Directory of Open Access Journals (Sweden)

    Hyeon Koo Kang

    2015-01-01

    Full Text Available Catalytic rapid pyrolysis of Quercus variabilis, a Korean native tree species, was carried out using Py-GC/MS. Mesoporous MFI, which has both nanopores and micropores, and three nanoporous materials, Al-MCM-41, Al-SBA-15, and γ-Al2O3, were used as the catalyst. The acid sites of mesoporous MFI were strong Brønsted acid sites, whereas those of nanoporous materials were mostly weak acid sites. The composition of the product bio-oil varied greatly depending on the acid characteristics of the catalyst used. Phenolics were the most abundant species in the bio-oil, followed by acids and furanics, obtained over Al-MCM-41 or Al-SBA-15 with weak acid sites, whereas aromatics were the most abundant species produced over mesoporous MFI with strong acid sites, followed by phenolics. Aromatics, phenolics, and furanics are all important chemicals contributing to the improvement of bio-oil quality.

  5. Moisture sorption isotherms and thermodynamic properties of Oak wood ( Quercus robur and Quercus canariensis): optimization of the processing parameters

    Science.gov (United States)

    Bahar, Rim; Azzouz, Soufien; Remond, Romain; Ouertani, Sahbi; Elaieb, Mohamed Taher; El Cafci, Mohamed Afif

    2017-05-01

    The aim of this paper was to determine the moisture desorption isotherms and essentials thermodynamic properties of two Oak wood varieties. Desorption isotherms were measured using a static gravimetric method at 50, 60, 70 and 80 °C within the range of 5-90 % relative humidity. The equilibrium moisture content decreased with increasing temperature and decreased with decreasing relative humidity at a constant temperature. The `Thermodynamic' sorption equation was found to be the best for describing the experimental moisture sorption isotherms of woods within the range of temperature and water activity investigated. The Fiber saturation point, deduced from the `Thermodynamic' model parameters, depends on the temperature and varying from 22.6 to 54.4 (% kg water/kg dry matter). Isosteric heat of desorption and differential entropy were calculated by applying Clausius-Clapeyron equation to the desorption data fitted by the `Thermodynamic' model. The isosteric heat of desorption and the differential entropy decreased with increasing moisture content according to an exponential law equation and varying from 2.03 to 31.14 kJ/mol and from 73.98 to 4.34 J/(mol K), respectively. The linear relationship between differential enthalpy and entropy satisfied the enthalpy-entropy compensation theory. The sign of Gibbs free energy was found to be positive (+283 J/mol) and (+97 J/mol) for Quercus robur and Quercus canariensis, respectively. The isokinetic temperature was found to be greater than the harmonic temperature. Based on the enthalpy-entropy compensation theory, it could be concluded that the moisture desorption isotherm of Oak wood is a non-spontaneous and enthalpy-controlled process.

  6. Moisture sorption isotherms and thermodynamic properties of Oak wood (Quercus robur and Quercus canariensis): optimization of the processing parameters

    Science.gov (United States)

    Bahar, Rim; Azzouz, Soufien; Remond, Romain; Ouertani, Sahbi; Elaieb, Mohamed Taher; El Cafci, Mohamed Afif

    2016-09-01

    The aim of this paper was to determine the moisture desorption isotherms and essentials thermodynamic properties of two Oak wood varieties. Desorption isotherms were measured using a static gravimetric method at 50, 60, 70 and 80 °C within the range of 5-90 % relative humidity. The equilibrium moisture content decreased with increasing temperature and decreased with decreasing relative humidity at a constant temperature. The `Thermodynamic' sorption equation was found to be the best for describing the experimental moisture sorption isotherms of woods within the range of temperature and water activity investigated. The Fiber saturation point, deduced from the `Thermodynamic' model parameters, depends on the temperature and varying from 22.6 to 54.4 (% kg water/kg dry matter). Isosteric heat of desorption and differential entropy were calculated by applying Clausius-Clapeyron equation to the desorption data fitted by the `Thermodynamic' model. The isosteric heat of desorption and the differential entropy decreased with increasing moisture content according to an exponential law equation and varying from 2.03 to 31.14 kJ/mol and from 73.98 to 4.34 J/(mol K), respectively. The linear relationship between differential enthalpy and entropy satisfied the enthalpy-entropy compensation theory. The sign of Gibbs free energy was found to be positive (+283 J/mol) and (+97 J/mol) for Quercus robur and Quercus canariensis, respectively. The isokinetic temperature was found to be greater than the harmonic temperature. Based on the enthalpy-entropy compensation theory, it could be concluded that the moisture desorption isotherm of Oak wood is a non-spontaneous and enthalpy-controlled process.

  7. Research and Development of the Structure and Physical Properties of Cork from Quercus suber L.%欧洲栓皮栎软木构造与物理性质研究进展

    Institute of Scientific and Technical Information of China (English)

    刘艳贞; 雷亚芳; 周伟; 赵泾峰; 史小娟

    2007-01-01

    介绍了国内外学者对欧洲栓皮栎软木宏观、微观构造的研究现状.欧洲栓皮栎软木细胞为14面体,弦切面细胞呈蜂窝状排列,横切面和径切面呈砖墙状排列;细胞壁上存在褶皱.欧洲栓皮栎软木具有密度低、弹性好、热绝缘性好、吸声减震和防水等优良物理性能.

  8. Relación entre la composición de las hojas, desfronde, hojarasca y suelo en un bosque mixto de Quercus Suber L. y Q. Canariensis Willd.

    OpenAIRE

    García, Luis V.; Aponte, Cristina; Pozuelos Rojas, Ana; Gutiérrez González, Eduardo; Florido Fernández, M.C.; Pérez-Ramos, Ignacio Manuel; Marañón, Teodoro

    2008-01-01

    7 páginas, 1 mapa, 2 tabla, 2 figuras, 5 diagramas.-- El trabajo se genera en el marco de las actividades de la Reunión del Grupo de Trabajo Ecología, Ecofisiología y Suelos Forestales en Actas de la II reunión sobre suelos forestales. --Nuevas perspectivas en las relaciones suelo-árbol.-- Salamanca, 22-23 de octubre 2007. http://www.irnase.csic.es/users/lventura/C25-201-207.pdf

  9. Seasonal dynamics of secondary growth and xylem anatomy in two coexisting Mediterranean Quercus; Dinamica estacional del crecimiento secundario y anatomia del xilema en dos Quercus mediterraneos que coexisten

    Energy Technology Data Exchange (ETDEWEB)

    Albuixech, J.; Camarero, J. J.; Montserrat-Marti, G.

    2012-11-01

    The contribution of secondary growth's patterns and wood anatomy on the coexistence of two species of Quercus (Quercus ilex subsp ballota diffused porous wood and Quercus faginea ring porous wood) were studied in a location with continental Mediterranean climate, which has been studied during two years with contrasted climatology. According to our results secondary growth pattern of Q. faginea is concentrated in the spring, starting before, and responding more than Q. ilex to a rainfall increase during this period. Q. ilex extends wood formation into the fall and late summer growth. Q. ilex growth during the fall and late summer has a greater importance in terms of theoretical hydraulic conductivity than in Q. faginea, which concentrates hydraulic conductivity in spring vessels. Therefore, different response of wood phenology formation and xylem anatomy in both species to the seasonal pattern of precipitation could contribute to explain the coexistence of Q. ilex and Q. faginea. (Author) 48 refs.

  10. Tvorba marketingovej stratégie internetového obchodu Quercus

    OpenAIRE

    Krahulcová, Lenka

    2011-01-01

    Diploma thesis is focused on creation of new marketing strategy for company QUERCUS' electronic store. Theoretical part deals with basic concepts of marketing and strategic marketing planning. It further introduces marketing mix specifics on the internet, basic aspects of electronic commerce and consumer behavior on internet. Practical part includes introduction of company QUERCUS, e-shop SWOT analysis, brief characteristic of current marketing strategy and finally proposal of new marketing s...

  11. Composition and ultrastructure of the suberized cell wall of isolated crystal idioblasts from Agave americana L. leaves.

    Science.gov (United States)

    Espelie, K E; Wattendorff, J; Kolattukudy, P E

    1982-07-01

    Styloid-calcium-oxalate-crystal-containing idioblasts possess an interior cell-wall layer which has a lamellar ultrastructure. Idioblasts were isolated by centrifugation of an Agave americana leaf homogenate through 2M sucrose. The aliphatic monomers of the polymeric material from an idioblast fraction were primarily ω-hydroxy acids (32%) and dicarboxylic acids (35%), with C18:1 dicarboxylic acid being the most dominant monomer (25%). Nitrobenzene oxidation of the idioblasts yielded syringaldehyde and vanillin in a ratio of 0.46:1. The major class of wax associated with the idioblasts was free fatty acids (34%). A major homologue of both the fatty acid and fatty alcohol fractions of this wax was C22. The hydrocarbon fraction of the wax had a broad chainlength distribution with a large amount of even-numbered (47%) and shorter-chain homologues. The ultrastructure, the composition of the aliphatic and aromatic components of the polymeric material as well as the composition of the wax show that the idioblast cell wall is suberized. The wax and cutin polymer of the epidermis of A. americana leaves were chemically characterized for comparative purposes.

  12. Microsatellite Primer Development for Post Oak, Quercus stellata (Fagaceae

    Directory of Open Access Journals (Sweden)

    Warren B. Chatwin

    2014-10-01

    Full Text Available Premise of the study: The American Cross Timbers forest ecosystem runs from southeastern Kansas to Central Texas and is primarily composed of post oak (Quercus stellata. This old-growth forest currently occupies only about 2% of its ancestral range. To facilitate genetic research on this species, we developed microsatellite primers specific to post oak from reduced genomic libraries. Methods and Results: Two Q. stellata individuals, sampled from the northern and southern range of the post oak forest, were subject to genomic reduction and 454 pyrosequencing. Bioinformatic analysis identified putative microsatellites from which 12 polymorphic primer sets were screened on three populations. The number of alleles observed ranged from five to 20 across all populations, while observed and expected heterozygosity values ranged from 0.05 to 0.833 and 0.236 to 0.893, respectively, within individual populations. Conclusions: We report the development of microsatellite markers, specific to post oak, to aid the study of genetic diversity and population structure of extant forest remnants.

  13. Mycorrhizas on nursery and field seedlings of Quercus garryana.

    Science.gov (United States)

    Southworth, Darlene; Carrington, Elizabeth M; Frank, Jonathan L; Gould, Peter; Harrington, Connie A; Devine, Warren D

    2009-03-01

    Oak woodland regeneration and restoration requires that seedlings develop mycorrhizas, yet the need for this mutualistic association is often overlooked. In this study, we asked whether Quercus garryana seedlings in nursery beds acquire mycorrhizas without artificial inoculation or access to a mycorrhizal network of other ectomycorrhizal hosts. We also assessed the relationship between mycorrhizal infection and seedling growth in a nursery. Further, we compared the mycorrhizal assemblage of oak nursery seedlings to that of conifer seedlings in the nursery and to that of oak seedlings in nearby oak woodlands. Seedlings were excavated and the roots washed and examined microscopically. Mycorrhizas were identified by DNA sequences of the internal transcribed spacer region and by morphotype. On oak nursery seedlings, predominant mycorrhizas were species of Laccaria and Tuber with single occurrences of Entoloma and Peziza. In adjacent beds, seedlings of Pseudotsuga menziesii were mycorrhizal with Hysterangium and a different species of Laccaria; seedlings of Pinus monticola were mycorrhizal with Geneabea, Tarzetta, and Thelephora. Height of Q. garryana seedlings correlated with root biomass and mycorrhizal abundance. Total mycorrhizal abundance and abundance of Laccaria mycorrhizas significantly predicted seedling height in the nursery. Native oak seedlings from nearby Q. garryana woodlands were mycorrhizal with 13 fungal symbionts, none of which occurred on the nursery seedlings. These results demonstrate the value of mycorrhizas to the growth of oak seedlings. Although seedlings in nursery beds developed mycorrhizas without intentional inoculation, their mycorrhizas differed from and were less species rich than those on native seedlings.

  14. Pharmacognostic studies of insect gall of Quercus infectoria Olivier (Fagaceae)

    Institute of Scientific and Technical Information of China (English)

    Savitri Shrestha; Vasuki Srinivas Kaushik; Ravi Shankara Birur Eshwarappa; Sundara Rajan Subaramaihha; Latha Muuaiah Ramanna; Dhananjaya Bhadrapura Lakkappa

    2014-01-01

    Objective:To study the detailed pharmacognostic profile of galls of Quercus infectoria Olivier (Q. infectoria olivier) (Fagaceae), an important medicinal plant used in the Indian system of medicine. Methods: Samples of galls of Q. infectoria were studied by macroscopical, microscopical, physiochemical, phytochemical, fluorescence analysis and othjer methods for standardization as recommended by WHO. Results:Macroscopically, the crude drug is globose with horny appearances on external surface (1.4-2.3 cm in length and 1-1.5 cm in diameter), with greyish-brown to brownish-black in colour externally and dark brown buff colored. Surface is smooth with numerous horny protuberances giving rough touch, and with unpleasant odour. Microscopically, a wide zone of radially elongated parenchyma cells between upper and lower epidermis were found. The vascular strands were present at all places and radially elongated sclerides touched the lower epidermis. In physico-chemical studies, the moisture, total ash, acid insoluble ash, alcohol soluble, water soluble, petroleum ether, chloroform extractive value and tannin content were found to be 2.790, 5.020, 0.110, 38.780, 41.210, 0.402, 1.590 and 49.200 percentage respectively. Preliminary phytochemical screening showed the presence of phenols, flavonoids, steroids, triterpenes, tannins, saponins and alkaloids. Conclusions:The results of the present study serve as a valuable source of information and provide suitable standards for identification of this medicinally important plant drug material for future investigations and applications.

  15. Variability of acorn anatomical characteristics in Quercus robur L. genotypes

    Directory of Open Access Journals (Sweden)

    Nikolić Nataša P.

    2010-01-01

    Full Text Available The aim of this study was to examine variability of acorn anatomical characteristics in seventeen Quercus robur L. genotypes. Acorns were collected in clonal seed orchard Banov Brod (Srem, Vojvodina, Serbia. Microscopic measurements were done for pericarp (total thickness, thickness of exocarp and mesocarp, seed coat (total thickness, thickness of outer epidermis, parenchyma, and inner epidermis, and embryo axis (diameter, thickness of cortical region, and diameter of stellar zone. Obtained results revealed certain divergence between genotypes. The thickness of pericarp varied from 418 to 559 mm (genotypes 20 and 22, respectively. On average, the participation of exocarp in the total thickness of pericarp was 36.3%, of mesocarp 61.0%, while of endocarp 2.6%. The thickness of seed coat for individual genotypes ranged from 71 mm (genotype 28 to 157 mm (genotype 38. In addition, anatomic parameters of embryo axis varied among studied genotypes. The lowest cortical zone thickness and stellar zone diameter were measured in genotype 40, while the highest values in genotype 33.

  16. Evaluation of antioxidant, free radical scavenging and antimicrobial, activity of Quercus incana Roxb.

    Directory of Open Access Journals (Sweden)

    Rizwana eSarwar

    2015-11-01

    Full Text Available Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content and antimicrobial activity of Quercus incana Roxb. In vitro antioxidant activity of the plant fractions were determined by DPPH and NO scavenging method. Total phenolic contents were determined by gallic acid equivalent (GAE and antimicrobial activities were determined by agar well diffusion method. It was observed that Quercus incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Quercus incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55 and Aspergillus flavus (28 mm ± 0.45. Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL was fairly good compared to other fractions. The current study of Quercus incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity.

  17. [Aboveground architecture and biomass distribution of Quercus variabilis].

    Science.gov (United States)

    Yu, Bi-yun; Zhang, Wen-hui; Hu, Xiao-jing; Shen, Jia-peng; Zhen, Xue-yuan; Yang, Xiao-zhou

    2015-08-01

    The aboveground architecture, biomass and its allocation, and the relationship between architecture and biomass of Quercus variabilis of different diameter classes in Shangluo, south slope of Qinling Mountains were researched. The results showed that differences existed in the aboveground architecture and biomass allocation of Q. variabilis of different diameter classes. With the increase of diameter class, tree height, DBH, and crown width increased gradually. The average decline rate of each diameter class increased firstly then decreased. Q. variabilis overall bifurcation ratio and stepwise bifurcation ratio increased then declined. The specific leaf areas of Q. variabilis of all different diameter classes at vertical direction were 0.02-0.03, and the larger values of leaf mass ratio, LAI and leaf area ratio at vertical direction in diameter level I , II, III appeared in the middle and upper trunk, while in diameter level IV, V, VI, they appeared in the central trunk, with the increase of diameter class, there appeared two peaks in vertical direction, which located in the lower and upper trunk. The trunk biomass accounted for 71.8%-88.4% of Q. variabilis aboveground biomass, while the branch biomass accounted for 5.8%-19.6%, and the leaf biomass accounted for 4.2%-8.6%. With the increase of diameter class, stem biomass proportion of Q. variabilis decreased firstly then increased, while the branch and leaf biomass proportion showed a trend that increased at first then decreased, and then increased again. The aboveground biomass of Q. variabilis was significantly positively correlated to tree height, DBH, crown width and stepwise bifurcation ratio (R2:1), and positively related to the overall bifurcation ratio and stepwise bifurcation ratio (R3:2), but there was no significant correlation. Trunk biomass and total biomass aboveground were negatively related to the trunk decline rate, while branch biomass and leaf biomass were positively related to trunk decline

  18. Quercus ilex L. carbon sequestration capability related to shrub size.

    Science.gov (United States)

    Gratani, Loretta; Catoni, Rosangela; Varone, Laura

    2011-07-01

    CO(2) sequestration capacity of Quercus ilex L., an evergreen species developing in shrub and forest communities widely distributed in the Mediterranean Basin, was analysed. Experiments were carried out in the period of January to December 2009 on 20 shrubs of different size, growing at the Botanical Garden of Rome. At shrub level, the largest differences concern total photosynthetic leaf surface area per shrub and shrub volume. Shrubs structure significantly contribute to reduce total irradiance and air temperature below the canopy. Leaf mass per area is higher in sun leaves than in shade ones (20 ± 1 and 12 ± 2 mg cm( -2), respectively). Sun leaves are also characterised by the highest leaf thickness (78% higher in sun than in shade leaves), the spongy parenchyma thickness (71% higher in sun than in shade leaves) and the highest adaxial cuticle thickness (7.2 ± 1.2 and 4.7 ± 0.5 μm, respectively). Net photosynthetic rates (P (N)) of sun and shade leaves are the highest in spring, and shade leaves contribute 6% to the whole shrub P (N). Q. ilex CO(2) sequestration depends on shrub size. In particular, the CO(2) sequestration per shrub was 0.20 ± 0.02 Kg CO(2) year( -1) in small shrubs, and it was 75% and 98% lower than in medium and large ones. The highest CO(2) sequestration is measured in spring, decreasing 77% during drought. Q. ilex may play a significant role in mitigating carbon dioxide concentration and lowering air and soil temperature in areas around the Mediterranean Basin.

  19. Quercus cerris extracts limit Staphylococcus aureus biofilm formation

    Science.gov (United States)

    Hobby, Gerren H.; Quave, Cassandra L.; Nelson, Katie; Compadre, Cesar M.; Beenken, Karen E.; Smeltzer, Mark S.

    2012-01-01

    Ethnopharmacological relevance Quercus cerris L., Fagaceae has been used in traditional Mediterranean medicine for numerous purposes, including anti-infective therapies for diarrhea and wound care. Aim of the study To evaluate the anti-staphylococcal activity of fractions of ethanolic extracts of Q. cerris leaf and stem/fruit samples in models for biofilm and growth inhibition. Materials and methods Ethanolic extracts of Q. cerris leaves and stems/fruits were prepared, resuspended in water and fractioned by successively partitioning with hexane, ethyl acetate and butanol. The ability of the fractions to inhibit Staphylococcus aureus biofilm formation was tested using static crystal violet staining methods and confocal laser scanning microscopy. Growth studies were conducted to determine if the diminished capacity to form a biofilm was related to growth inhibition. Results The butanol extracts of both the leaf and stem/fruit samples were the most active, and at a dose of 200 μg/ml, the capacity to form a biofilm was limited to a level equivalent to that of the sarA mutant controls. Further examination of the impact of these fractions on S. aureus growth revealed that biofilm inhibition by the leaf butanol fraction was due to its bacteriostatic activity. The stem/fruit butanol fraction, however, showed a limited impact on growth, thus demonstrating that biofilm inhibition in this case is not related to the bacteriostatic activity of the extract. Conclusion Our evaluation of a medicinal plant used in Mediterranean ethnotherapies for infectious disease has demonstrated significant activity in the inhibition of staphylococcal biofilm formation with a mechanism unrelated to staphylococcal growth inhibition. These results contribute towards validation of this botanical remedy and form the groundwork for future studies in the search for novel biofilm inhibiting drugs. PMID:23127649

  20. Preliminary Comparative Analysis of Phenological Varieties of Quercus robur by ISSR-Markers

    Directory of Open Access Journals (Sweden)

    Vasiliy Chokheli

    2016-01-01

    Full Text Available Quercus robur L. is a valuable wood species having long ontogeny and promising to create long-living artificial plantings of recreational and ameliorative purposes in the steppes zone of Russia and other countries. In this work we have performed the genotyping of varieties of Quercus robur L. obtained from collection of Botanical Garden of Southern Federal University using intersimple sequence repeat (ISSR molecular markers. The most polymorphic ISSR-marker (GA 8YC was found in the collection. The polymorphic DNA markers identified in the present study can be used for the future breeding works to obtain valuable genotypes of Quercus genus. In addition we have performed DNA fingerprinting of the prospective sample of the variety Q. robur var. tardiflora Czern.

  1. 40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Plant extract derived from Opuntia... Tolerances § 180.1179 Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and... derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria mangle is exempted...

  2. Rapid radiosynthesis of [11C] and [14C]azelaic, suberic, and sebacic acids for in vivo mechanistic studies of systemic acquired resistance in plants

    Energy Technology Data Exchange (ETDEWEB)

    Best M.; Fowler J.; Best, M.; Gifford, A.N.; Kim, S.W.; Babst, B.; Piel, M.; Roesch, F.; Fowler, J.S.

    2011-11-25

    A recent report that the aliphatic dicarboxylic acid, azelaic acid (1,9-nonanedioic acid) but not related acids, suberic acid (1,8-octanedioic acid) or sebacic (1,10-decanedioic acid) acid induces systemic acquired resistance to invading pathogens in plants stimulated the development of a rapid method for labeling these dicarboxylic acids with {sup 11}C and {sup 14}C for in vivo mechanistic studies in whole plants. {sup 11}C-labeling was performed by reaction of ammonium [{sup 11}C]cyanide with the corresponding bromonitrile precursor followed by hydrolysis with aqueous sodium hydroxide solution. Total synthesis time was 60 min. Median decay-corrected radiochemical yield for [{sup 11}C]azelaic acid was 40% relative to trapped [{sup 11}C]cyanide, and specific activity was 15 GBq/{micro}mol. Yields for [{sup 11}C]suberic and sebacic acids were similar. The {sup 14}C-labeled version of azelaic acid was prepared from potassium [{sup 14}C]cyanide in 45% overall radiochemical yield. Radiolabeling procedures were verified using {sup 13}C-labeling coupled with {sup 13}C-NMR and liquid chromatography-mass spectrometry analysis. The {sup 11}C and {sup 14}C-labeled azelaic acid and related dicarboxylic acids are expected to be of value in understanding the mode-of-action, transport, and fate of this putative signaling molecule in plants.

  3. Modeling of stomatal conductance to estimate stomatal ozone uptake by Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla.

    Science.gov (United States)

    Kinose, Yoshiyuki; Azuchi, Fumika; Uehara, Yui; Kanomata, Tomoaki; Kobayashi, Ayumi; Yamaguchi, Masahiro; Izuta, Takeshi

    2014-11-01

    To construct stomatal conductance models and estimate stomatal O3 uptake for Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla, stomatal conductance (gs) was measured in seedlings of the four tree species. Better estimates of gs were made by incorporating the acute effects of O3 on gs into the models and the models could explain 34-52% of the variability in gs. Although the O3 concentration was relatively high in spring from April to May, COU of F. crenata, Q. serrata and Q. mongolica var. crispula were relatively low and the ratios of COU in spring to total COU in one year were 16.8% in all tree species because of low gs limited mainly by leaf pre-maturation and/or low temperature. The COU of B. platyphylla were relatively high mainly because of rapid leaf maturation and lower optimal temperature for stomatal opening.

  4. Organic C distribution and N mineralization in soil of oak woodlands with improved pastures Distribuição espacial do C orgânico e da mineralização de N em solos de montado com pastagem melhorada

    Directory of Open Access Journals (Sweden)

    Maria Xesús Gómez-Rey

    2011-01-01

    Full Text Available Cork oak woodlands in Portugal are a multipurpose agroforestry system occurring in areas mostly degraded by former cereal crops and overgrazing. The objective of this study was to evaluate the effect of scattered cork oak trees (Quercus suber L. on soil quality, considering two land use systems: unmanaged pastures and improved pastures. Soil samples were collected in a square grid around scattered cork oak trees to evaluate the spatial variability of soil bulk density and chemical properties. In soil samples taken beneath tree canopy and in the open, net N mineralization was evaluated by aerobic incubations. Also, laboratory incubations were carried out to evaluate the effect of roots (tree or/and herbaceous and water solutions (bulk precipitation, throughfall or stemflow on net N mineralization.Contents of organic C, total N and extractable P were increased beneath the tree canopy, and gradually decreased with the increase of distance to the tree trunk. Improved pastures established 26 years ago increased organic C (0.76 kg m-2, total N (0.06 kg m-2 and extractable P (2.70 g m-2 amounts in the 0-10 cm soil layer beneath the tree canopy relatively to those of unmanaged pastures. Net N mineralization was significantly greater (about 2 times in soils beneath the tree canopy than in those of open areas. N mineralization was unaffected by addition of throughfall or stemflow, while a significant reduction resulted from tree roots addition, this effect being stronger for herbaceous plant roots than for tree roots. Maintenance of tree cover combined with permanent improved pastures should be considered to improve soil quality in oak woodlands of Southern Portugal.O montado em Portugal corresponde a um sistema multifuncional que ocorre em áreas frequentemente degradadas pelo cultivo de cereais e de sobre pastoreio. O objectivo deste estudo foi avaliar a influência das árvores espaçadas na variação do C orgânico, N total e P extraível num montado

  5. Xylem dysfunction in Quercus: vessel sizes, tyloses, cavitation and seasonal changes in embolism.

    Science.gov (United States)

    Cochard, H; Tyree, M T

    1990-12-01

    The seasonal progression of xylem dysfunction from tyloses and embolism induced both by cavitation and frost was studied in Quercus rubra L. and Quercus alba L. branches. Vessel lengths and diameters were measured in current-year rings of branches of various ages. Vessels in current-year shoots are about the same size as those in many diffuse porous trees, but vessels in older branches are two to six times larger in diameter and typically more than 10 times longer. Large Quercus vessels were more vulnerable to cavitation than small vessels. The small vessels in current-year shoots were more vulnerable to cavitation than vessels of comparable size in diffuse porous species. Earlywood vessels are completely blocked by tyloses within a year of their formation. Tylose growth starts in winter, but the vessels are not fully blocked until the next summer. Many latewood vessels, by contrast, remain free of complete blockage for several years. In Q. rubra, loss of hydraulic conductivity in current-year shoots due to cavitation reaches 20% by August and > 90% after the first hard frost. Both laboratory and field observations confirm that the role of frost in causing loss of hydraulic conduction by embolism is much more dramatic in Quercus than in conifers and diffuse porous hardwoods.

  6. Intraspecific Phenotypic Variation and Ecological Genetics of Blue Oak (Quercus douglasii Hook. & Am.)

    Science.gov (United States)

    Kevin J. Rice; Doria R. Gordon; Jeanine L. Hardison; Jeffrey M. Welker

    1991-01-01

    A field experiment was conducted to examine the effects of soil water availability on blue oak (Quercus douglasii) seedling establishment. Acorns were planted either into cleared plots of 0, 10, 20, or 40 cm diameter. The cleared plots were located in two grazed and one ungrazed site. Half of the plots received drip irrigation in a split plot design...

  7. The effect of seed size variation in Quercus pacifica on seedling establishment and growth

    Science.gov (United States)

    Mario B. Pesendorfer

    2015-01-01

    Quercus pacifica, the island scrub-oak, is the dominant species in oak chaparral on the three largest California Channel Islands. While the population on Santa Cruz Island has experienced a strong recovery, the populations on Santa Rosa and Santa Catalina islands are of conservation concern, and managers are actively restoring oak habitat by...

  8. A bibliography for Quercus garryana and other geographically associated and botanically related oaks.

    Science.gov (United States)

    Constance A. Harrington; Melanie A. Kallas

    2002-01-01

    Interest in Quercus garryana Dougl. ex Hook., commonly known as Oregon white oak or Garry oak, has increased in recent years as scientists, resource managers, and the general public focus attention on a forest type in decline. To aid those interested in learning what has previously been reported on this species, we have compiled a comprehensive bibliography for Q....

  9. Estudio taxonómico de cuatro especies de encino (Quercus) descritas por Warburg

    OpenAIRE

    1995-01-01

    Se determinaron como sinónimos de Quercus hintonii Warb. a Q. apiophylla Warb., Q. ochroestes Warb. y Q. sagata Warb., con base en el análisis de las descripciones originales, fototipos y ejemplares existentes en los herbarios. Además se realizaron observaciones de las poblaciones y colectas de ejemplares en las localidades tipo.

  10. Indicator values for lichens on Quercus as a tool to monitor ammonia pollution in Denmark

    DEFF Research Database (Denmark)

    Berthelsen, K.; Olsen, H. B.; Søchting, Ulrik

    2008-01-01

    The epiphytic lichen vegetation on solitary Quercus trees was investigated on 13 locations in Denmark in order to test the usability of indicator values to quantify ammonia deposition from the ambient air. Indicator values calculated for each location corresponded well with the expected ecological...

  11. Concentric Ring Method for generating pollen maps. Quercus as case study.

    Science.gov (United States)

    Oteros, Jose; Valencia, Rosa Mª; Del Río, Sara; Vega, Ana Mª; García-Mozo, Herminia; Galán, Carmen; Gutiérrez, Pablo; Mandrioli, Paolo; Fernández-González, Delia

    2017-01-15

    Mapping pollen concentrations is of great interest to study the health impact and ecological implications or for forestry or agronomical purposes. A deep knowledge about factors affecting airborne pollen is essential for predicting and understanding its dynamics. The present work sought to predict annual Quercus pollen over the Castilla and León region (Central and Northern Spain). Also to understand the relationship between airborne pollen and landscape. Records of Quercus and Quercus pyrenaica pollen types were collected at 13 monitoring sites over a period of 8years. They were analyzed together with land use data applying the Concentric Ring Method (CRM), a technique that we developed to study the relationship between airborne particle concentrations and emission sources in the region. The maximum correlation between the Quercus pollen and forms of vegetation was determined by shrubland and "dehesa" areas. For the specific Qi pyrenaica model (Q. pyrenaica pollen and Q. pyrenaica forest distribution), the maximum influence of emission sources on airborne pollen was observed at 14km from the pollen trap location with some positive correlations up to a distance of 43km. Apart from meteorological behavior, the local features of the region can explain pollen dispersion patterns. The method that we develop here proved to be a powerful tool for multi-source pollen mapping based on land use. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Predicting the height growth of oak species (Quercus) reproduction over a 23-year period following clearcutting

    Science.gov (United States)

    J. Travis Swaim; Daniel C. Dey; Michael R. Saunders; Dale R. Weigel; Christopher D. Thornton; John M. Kabrick; Michael A. Jenkins

    2016-01-01

    We resampled plots from a repeated measures study implemented on the Hoosier National Forest (HNF) in southern Indiana in 1988 to investigate the influence of site and seedling physical attributes on height growth and establishment success of oak species (Quercus spp.) reproduction in stands regenerated by the clearcut method. Before harvest, an...

  13. Epiphytic bryophytes of Quercus forests in Central and North inland Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Nagore García Medina

    2015-04-01

    Full Text Available Diversity patterns are governed by a complex network of interacting factors. Studies directed to disentangle the most important factors affecting diversity have frequently shown divergent results, which has encouraged a rewarding debate about the relative importance of each factor. Scale dependency has been identified as a direct cause of at least part of such divergences. However, studies with spatially-explicit measurements at different scales are costly and therefore they are relatively scarce despite their importance. Here, we present a database to disentangle the cross-scale variation in the importance of factors affecting the diversity of epiphytic bryophyte communities in Quercus dominated forests (Quercus ilex L., Quercus pyrenaica Willd. and Quercus faginea Lam. in the North-western region of the Iberian Peninsula. We provide species-per-site abundance information with more than 9000 entries and an environmental table containing 20 in situ measured variables at three different scales (forest, stand, and sample. The database will help to advance the research of cross-scale effects of diversity patterns while at the same time providing valuable information on the distribution of a poorly known group of organisms. 

  14. Indicator values for lichens on Quercus as a tool to monitor ammonia pollution in Denmark

    DEFF Research Database (Denmark)

    Berthelsen, K.; Olsen, H. B.; Søchting, Ulrik

    2008-01-01

    The epiphytic lichen vegetation on solitary Quercus trees was investigated on 13 locations in Denmark in order to test the usability of indicator values to quantify ammonia deposition from the ambient air. Indicator values calculated for each location corresponded well with the expected ecological...... as a tool for quantitative estimation of ammonia deposition in relation to sensitive Danish ecosystems.  ...

  15. Estudio morfométrico de Quercus sartorii y Q. xalapensis (Fagaceae Morphometric study of Quercus sartorii and Q. xalapensis (Fagaceae

    Directory of Open Access Journals (Sweden)

    Dorismilda Martínez-Cabrera

    2011-06-01

    Full Text Available Se realizó un estudio morfométrico con la finalidad de contribuir en la delimitación taxonómica de Quercus sartorii y Q. xalapensis. Para ello, se revisó material de herbario y se recolectó material en 11 poblaciones distribuidas en los estados de Hidalgo, San Luis Potosí, Tamaulipas y Veracruz, en México, incluyendo 2 poblaciones simpátricas. Los resultados del análisis de componentes principales y discriminante mostraron que los caracteres que contribuyeron a agrupar los individuos en su respectiva especie son los relacionados con el tamaño del fruto, en particular el diámetro de la bellota, de la nuez y de la cúpula. La bellota de Q. sartorii es de menor tamaño que la de Q. xalapensis. La variación detectada no se atribuyó a la latitud o altitud. El fenograma mostró la separación de 2 grupos que corresponden a los individuos de las 2 especies estudiadas, si los caracteres del fruto son incluidos. Además, de los caracteres cuantitativos ya mencionados, 3 del patrón de venación y 2 anatómicos contribuyeron a reconocer los individuos de cada especie. Estas diferencias se mantuvieron en los individuos de las poblaciones simpátricas, por lo que los resultados apoyaron la distinción de Quercus sartorii y Q. xalapensis.A morphometric study was carried out in order to evaluate morphological variation of Quercus sartorii and Q. xalapensis and to contribute to their taxonomic delimitation. Herbarium specimens and material of 11 populations from Mexico in the states of Hidalgo, San Luis Potosí, Tamaulipas, and Veracruz, including 2 sympatric populations, were studied. Characters from foliar architecture, fruits and anatomical features of periderm and wood were analyzed through multivariate and phenetic methods. Principal component and discriminant analyses showed that fruit characters such as acorn, nut, and cupule diameters contributed to group individuals in their species, the acorn of Q. sartorii being smaller than that of Q

  16. Responses of evergreen and deciduous Quercus species to enhanced ozone levels

    Energy Technology Data Exchange (ETDEWEB)

    Calatayud, Vicent, E-mail: calatayud_viclor@gva.e [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Cervero, Julia; Calvo, Esperanza [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Garcia-Breijo, Francisco-Jose [Laboratorio de Anatomia e Histologia Vegetal ' Julio Iranzo' , Jardin Botanico, Universitat de Valencia, c/Quart 80, 46008 Valencia (Spain); Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Reig-Arminana, Jose [Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Sanz, Maria Jose [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain)

    2011-01-15

    Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD{sub 1.6}) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

  17. Characterization of Acorn Fruit Oils Extracted from Selected Mediterranean Quercus Species

    Directory of Open Access Journals (Sweden)

    Al-Rousan, W. M.

    2013-12-01

    Full Text Available The present study is aimed to identifying the acorn fruit oil composition of three Mediterranean white oak group species, Quercus aegilops (QA, Quercus infectoria (QI, and Quercus calliprinus (QC. Samples were estimated for the oil contents of acorn fruits, oil chemical and physical constants, fatty acid profile, tocopherols, phenolic compounds, and sterols.The oil content, expressed as dry weight, was found to be 3.40-7.51%. The physical and chemical constants included specific gravity 0.912-0.922, refractive index 1.4529-1.4645, specific extinction at 232 nm 2.497-2.536 and at 270 nm 1.495-2.037, iodine value 75.2-87.6, and saponification value 192.6-219.4. The fatty acid compositions were determined by GC as methyl esters. The most abundant fatty acids were oleic (53.3-56.1%, linoleic 21.3-23.4%, palmitic 17.8-18.7%, linolenic 1.5-1.6% and stearic acid 1.02-1.60%. The Tocopherol content was high in the range of 1440-1783 mg kg-1, γ-tocopherol constituted 84-91% of total tocopherols. Phenolic compounds were in remarkable amounts in all the three species 84-109 mg gallic acid kg-1 oil. Total sterol contents were between 2040-2480 mg kg-1 oil, with β-sitosterol being the main component comprising of 77.20-84.61%, followed by ∆5-avenasterol (5.8-11.4%, campesterol (3.6-4.5%, and stigmasterol (2.6-3.8. The cholesterol content was relatively high (0.42-0.55%.El presente estudio tuvo como objetivo identificar la composición de aceites de bellota de tres especies del grupo del roble blanco del Mediterráneo, Quercus Aegilops (QA, Quercus infectoria (QI y Quercus calliprinus (QC. Las muestras fueron evaluadas por el contenido de aceite, parámetros físico-químicos del aceite, perfil de ácidos grasos, tocoferoles, compuestos fenólicos y esteroles. El contenido de aceite, expresado en peso seco encontrado fue de 3,40 a 7,51%. Las constantes físico-químicas fueron: densidad 0,912-0,922, índice de refracción 1,4529 a 1,4645, extinción espec

  18. Fitotoxicidad del fosfonato en brinzales de encina Quercus ilex L. subsp. ballota (Desf.) Samp.

    OpenAIRE

    Jorge, Inmaculada; Porras Tejero, Carlos Javier; Jorrín-Novo, Jesús V.; Ariza-Mateos, David; Navarro Cerrillo, Rafael M.

    2007-01-01

    El fosfonato es un fertilizante foliar que ha sido utilizado con éxito en el control de P. cinnamomi en varias especies forestales. Aunque se considera que los fosfonatos tienen un bajo nivel de toxicidad, se han observado síntomas de daños en varias especies y utilizando distintos métodos de aplicación. En este trabajo se estudia la fitotoxicidad de los fosfonatos en brinzales de Quercus ilex. Se han ensayado dos concentraciones de fosfonato, 10 y 15 g l-1, y se han realizado medidas de la f...

  19. Caracterización energética de Quercus robur L.

    OpenAIRE

    González Rodríguez, Alberto Jesús

    2016-01-01

    En esta Tesis se buscan justificaciones sólidas que respalden la implantación de un proceso de silvicultura eficaz aplicable a las masas de Quercus con el doble objetivo de sanearlas a la vez que extraer de ellas biomasa forestal de calidad utilizable en procesos de producción energética a pequeña escala. Para conseguir estos dos objetivos debemos primero plantear la importancia actual del carballo en Galicia en su contexto más global y justificar así una inversión importante en labores silví...

  20. Drying of the aqueous extract of acorn Quercus robur in a spout-fluid bed

    Directory of Open Access Journals (Sweden)

    Rakić S.

    2005-01-01

    Full Text Available The results of the chemical investigations of variously treated acorn samples are presented in this paper with the aim of obtaining data on the amount of nutritious components and biologically active substances. The Quercus robur acorn, which belongs to the Fagaceae family, was investigated in a raw, thermally treated form and as an extract that was subsequently dried in a dryer with a fluidized bed. The obtained results regarding the content of tannin, nitrogen containing compounds, macro- and microelements indicate that acorn maintains its functional characteristics after the investigated treatments.

  1. Histological investigation of the multiplication step in secondary somatic embryogenesis of Quercus robur L.

    OpenAIRE

    2001-01-01

    International audience; Standardized explants composed of hypocotyl and root-tip were prepared from embryonic structures obtained from one embryogenic line of Quercus robur L. maintained by regular transfer onto a solidified reference medium composed of the MS mineral solutions, glucose (0.12 M), casamino acid (0.1% ), and NAA (10.74 $\\mu$M). The regeneration capacity from these explants were tested on the reference medium and on 2 alternative media in which the NAA (10.74 $\\mu$M) was omitted...

  2. Comparative of Quercus spp. and Salix spp. for phytoremediation of Pb/Zn mine tailings.

    Science.gov (United States)

    Shi, Xiang; Wang, Shufeng; Sun, Haijing; Chen, Yitai; Wang, Dongxue; Pan, Hongwei; Zou, Yazhu; Liu, Jianfeng; Zheng, Linyu; Zhao, Xiulian; Jiang, Zeping

    2017-02-01

    A pot experiment was conducted to evaluate the feasibility of using tree seedlings for the phytoremediation of lead/zinc (Pb/Zn) mine tailings. Seedlings of three Quercus spp. (Q. shumardii, Q. phellos, and Q. virginiana) and rooted cuttings of two Salix spp. (S. matsudana and S. integra) were transplanted into pots containing 50 and 100 % Pb/Zn mine tailings to evaluate their tolerance of heavy metals. The five species showed different tolerance levels to the Pb/Zn tailings treatments. Q. virginiana was highly tolerant to heavy metals and grew normally in the Pb/Zn tailings. The root systems showed marked differences between the Quercus spp. and Salix spp., indicating that different mechanisms operated to confer tolerance of heavy metals. The maximum efficiency of photosystem II photochemistry value of the five species showed no differences among the treatments, except for Q. shumardii. All species showed low metal translocation factors (TFs). However, S. integra had significantly higher TF values for Zn (1.42-2.18) and cadmium (1.03-1.45) than did the other species. In this respect, Q. virginiana showed the highest tolerance and a low TF, implying that it is a candidate for phytostabilization of mine tailings in southern China. S. integra may be useful for phytoextraction of tailings in temperate regions.

  3. Polyphenol deposition in leaf hairs of Olea europaea (Oleaceae) and Quercus ilex (Fagaceae).

    Science.gov (United States)

    Karabourniotis, G; Kofidis, G; Fasseas, C; Liakoura, V; Drossopoulos, I

    1998-07-01

    The subcellular localization (cytoplasm, vacuoles, cell walls) of polyphenol compounds during the development of the multicellular nonglandular leaf hairs of Olea europaea (scales) and Quercus ilex (stellates), was investigated. Hairs of all developmental stages were treated with specific inducers of polyphenol fluorescence, and the bright yellow-green fluorescence of individual hairs was monitored with epifluorescence microscopy. During the early ontogenetic stages, bright fluorescence was emitted from the cytoplasm of the cells composing the multicellular shield of the scales of O. europaea. Transmission electron micrographs of the same stages showed that these cells possessed poor vacuolation and thin cell walls. The nucleus of these cells may be protected against ultraviolet-B radiation damage. The progressive vacuolation that occurred during maturation was followed by a shifting of the bright green-yellow fluorescence from the perinuclear region and the cytoplasm to the cell walls. The same trends were observed during the development of the nonglandular stellate hairs of Quercus ilex, in which maturation was also accompanied by a considerable secondary thickening of the cell walls. Despite the differences in morphology, high concentrations of polyphenol compounds are initially located mainly in the cytoplasm of the developing nonglandular hairs, and their deposition on the cell walls takes place during the secondary cell wall thickening. These structural changes during the development of the leaf hairs make them a very effective barrier against abiotic (uv-B radiation) and probably biotic (pathogenic) stresses.

  4. Isolation of antibacterial compounds from Quercus dilatata L. through bioassay guided fractionation

    Directory of Open Access Journals (Sweden)

    Jamil Maryam

    2012-05-01

    Full Text Available Abstract Background Four medicinal plants (Chrozophora hierosolymitana Spreng, Chrysanthemum leucanthemum L., Ephedra gerardiana Wall. ex Stapf, and Quercus dilatata L. used by indigenous healers to treat various infectious diseases were selected for the present study. The major objective of the present study was isolation and characterization of antimicrobial components from the crude plant extracts using bioassay guided fractionation. Methods Seven methanolic extracts of the four plants were screened to identify any antimicrobial agents present in them. The active crude plant extract was fractionated first by solvent partitioning and then by HPLC. Characterization of the active fractions was done by using spectrophotometer. Results All the seven methanolic extracts showed low antifungal activity, however, when these extracts were tested for antibacterial activity, significant activity was exhibited by two extracts. The extract of aerial parts of Q. dilatata was most active and therefore, was selected for further analysis. Initially fractionation was done by solvent-solvent partitioning and out of six partitioned fractions, ethanol fraction was selected on the basis of results of antibacterial activity and phytochemical analysis. Further, fractionation was carried out by RP- HPLC and purified active subfractions were characterized by comparing their absorption spectra with that of the known natural products isolated from the plants of Quercus genus. Discussion and conclusion The results suggest that this is the first report of the isolated antibacterial compounds from this genus.

  5. Post-fire ecological restoration of a mixed Pinus-Quercus forest in northeastern Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Alanís-Rodríguez

    2015-01-01

    Full Text Available La presente investigación se desarrolló en un bosque de Pinus-Quercus en el Parque Ecológico Chipinque (noreste de México, el cual fue afectado por un incendio forestal y sometido a tratamiento de restauración ecológica. Los objetivos fueron evaluar el establecimiento artificial de Pinus pseudostrobus (Lindl. y analizar el efecto de las barreras de retención de suelo después de 10 años de su instalación. Para ello se estableció un área de estudio con tratamiento de restauración ecológica y otra área sin tratamiento en las que se muestreó la comunidad vegetal y la profundidad del suelo. De acuerdo con los resultados, se registró 35 % de supervivencia de la plantación, la cual se considera como no aceptable. Las barreras de retención de suelo tuvieron efecto positivo, pues incrementaron la profundidad del suelo hasta 25 %. Con la investigación se concluye que las técnicas de restauración post-incendio aplicadas han sido eficaces, ya que incorporan una especie clave de ecosistemas maduros y evitan la pérdida de suelo por arrastre, por lo que se recomienda su uso en rodales de Pinus-Quercus afectados por incendios en la Sierra Madre Oriental.

  6. Biochemistry of Suberization: Incorporation of [1-C]Oleic Acid and [1-C]Acetate into the Aliphatic Components of Suberin in Potato Tuber Disks (Solanum tuberosum).

    Science.gov (United States)

    Dean, B B; Kolattukudy, P E

    1977-01-01

    Biosynthesis of the aliphatic components of suberin was studied in suberizing potato (Solanum tuberosum) slices with [1-(14)C]oleic acid and [1-(14)C]acetate as precursors. In 4-day aged tissue, [1-(14)C]oleic acid was incorporated into an insoluble residue, which, upon hydrogenolysis (LiA1H(4)), released the label into chloroform-soluble products. Radio thin layer and gas chromatographic analyses of these products showed that (14)C was contained exclusively in octadecenol and octadecene-1, 18-diol. OsO(4) treatment and periodate cleavage of the resulting tetraol showed that the labeled diol was octadec-9-ene-1, 18-diol, the product expected from the two major components of suberin, namely 18-hydroxyoleic acid and the corresponding dicarboxylic acid. Aged potato slices also incorporated [1-(14)C]acetate into an insoluble material. Hydrogenolysis followed by radio chromatographic analyses of the products showed that (14)C was contained in alkanols and alkane-alpha,omega-diols. In the former fraction, a substantial proportion of the label was contained in aliphatic chains longer than C(20), which are known to be common constituents of suberin. In the labeled diol fraction, the major component was octadec-9-ene-1,18-diol, with smaller quantities of saturated C(16), C(18), C(20), C(22), and C(24)-alpha,omega-diols. Soluble lipids derived from [1-(14)C]acetate in the aged tissue also contained labeled very long acids from C(20) to C(28), as well as C(22) and C(24) alcohols, but no labeled omega-hydroxy acids or dicarboxylic acids were detected. Label was also found in n-alkanes isolated from the soluble lipids, and the distribution of label among them was consistent with the composition of n-alkanes found in the wound periderm of this tissue; C(21) and C(23) were the major components with lesser amounts of C(19) and C(25). The amount of (14)C incorporated into these bifunctional monomers in 0-, 2-, 4-, 6-, and 8-day aged tissue were 0, 1.5, 2.5, 0.8, and 0.3% of the

  7. One-step purification of twin-strep-tagged proteins and their complexes on strep-tactin resin cross-linked with bis(sulfosuccinimidyl) suberate (BS3).

    Science.gov (United States)

    Ivanov, Konstantin I; Bašić, Marta; Varjosalo, Markku; Mäkinen, Kristiina

    2014-04-20

    Affinity purification of Strep-tagged fusion proteins on resins carrying an engineered streptavidin (Strep-Tactin) has become a widely used method for isolation of protein complexes under physiological conditions. Fusion proteins containing two copies of Strep-tag II, designated twin-Strep-tag or SIII-tag, have the advantage of higher affinity for Strep-Tactin compared to those containing only a single Strep-tag, thus allowing more efficient protein purification. However, this advantage is offset by the fact that elution of twin-Strep-tagged proteins with biotin may be incomplete, leading to low protein recovery. The recovery can be dramatically improved by using denaturing elution with sodium dodecyl sulfate (SDS), but this leads to sample contamination with Strep-Tactin released from the resin, making the assay incompatible with downstream proteomic analysis. To overcome this limitation, we have developed a method whereby resin-coupled tetramer of Strep-Tactin is first stabilized by covalent cross-linking with Bis(sulfosuccinimidyl) suberate (BS3) and the resulting cross-linked resin is then used to purify target protein complexes in a single batch purification step. Efficient elution with SDS ensures good protein recovery, while the absence of contaminating Strep-Tactin allows downstream protein analysis by mass spectrometry. As a proof of concept, we describe here a protocol for purification of SIII-tagged viral protein VPg-Pro from nuclei of virus-infected N. benthamiana plants using the Strep-Tactin polymethacrylate resin cross-linked with BS3. The same protocol can be used to purify any twin-Strep-tagged protein of interest and characterize its physiological binding partners.

  8. Penicillium cecidicola, a new species on cynipid insect galls on Quercus pacifica in the western United States

    DEFF Research Database (Denmark)

    Seifert, K.A.; Hoekstra, E.H.; Frisvad, Jens Christian

    2004-01-01

    A synnematous species of Penicillium subgenus Biverticillium was found inside emergence tunnels from insect galls (Cynipidae, Hymenoptera, the so-called gall wasps) on scrub oaks (Quercus pacifica Nixon & C.H. Muller) collected in the western United States. The fungus produces synnemata with white...

  9. Effects of above- and below-ground competition from shrubs on photosynthesis, transpiration and growth in Quercus robur L

    Science.gov (United States)

    Anna M. Jensen; Magnus Lof; Emile S. Gardiner

    2011-01-01

    For a tree seedling to successfully establish in dense shrubbery, it must maintain function under heterogeneous resource availability. We evaluated leaf-level acclimation in photosynthetic capacity, seedling-level transpiration, and seedling morphology and growth to gain an understanding of the effects of above- and below-ground competition on Quercus robur seedlings....

  10. Distribution of Quercus agrifolia mycorrhizae deep within weathered bedrock: a potential mechanism for transport of stored water

    Science.gov (United States)

    M. Bornyasz; R. Graham; M. Allen

    2002-01-01

    In southwestern California, Quercus agrifolia distribution closely matches regions of granitic regolith. High annual evapotranspiration demand and inherent shallow soil conditions lead to a dependence on a deep rooting system and an ability to access water from deep within the regolith. Most of the plant available water in weathered granitic rock is...

  11. Root desiccation and drought stress responses of bareroot Quercus rubra seedlings treated with a hydrophilic polymer root dip

    Science.gov (United States)

    Kent G. Apostol; Douglass F. Jacobs; R. Kasten Dumroese

    2009-01-01

    Root hydrogel, a hydrophilic polymer, has been used to improve transplanting success of bareroot conifer seedlings through effects on water holding capacity. We examined mechanisms by which Terra-sorb Fine Hydrogel reduces damage that occurs when roots of 1-year old, dormant northern red oak (Quercus rubra L.) were subjected to shortterm (1, 3, and 5...

  12. Interactive effects of O3 exposure on California black oak (Quercus kelloggii Newb.) seedlings with and without N amendment

    Science.gov (United States)

    T. Handley; Nancy Grulke

    2008-01-01

    We examined the short-term separate and combined effects of simulated nitrogen (N) deposition (fertilization) and ozone (O3) exposure on California black oak seedlings (Quercus kelloggii Newb.), an ecologically important tree of the San Bernardino Mountains downwind of Los Angeles. Realistic concentrations of O3...

  13. Artificial regeneration of major oak (Quercus) species in the eastern United States - a review of the literature

    Science.gov (United States)

    Daniel C. Dey; Douglass Jacobs; Ken McNabb; Gary W. Miller; V. Baldwin; G. Foster

    2008-01-01

    Although natural regeneration is often the best method for establishing new oak (Quercus spp.) stands, there are increasingly more situations in which high potential for oak regeneration failure dictates the use of artificial regeneration including direct seeding and planting seedlings. Additionally, afforestation planting programs frequently...

  14. Effects of Northern red oak (Quercus rubra L. and sessile oak (Quercus petraea (Mattusch. Liebl. on the forest soil chemical properties

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    Miltner Stanislav

    2016-09-01

    Full Text Available Northern red oak (Quercus rubra L. is one of the most important introduced tree species in the Czech Republic, occupying about 6,000 ha with ca. 900,000 m3 of the standing volume. The presented study aims to evaluate its soil forming effects on natural oak sites. Soil chemistry of the upper soil layers (F+H, Ah, B horizons was studied in three pairs of stands of both species. In each stand, four bulk samples were taken separately for particular horizons, each consisting of 5 soil-borer cores. The soil characteristics analysed were: pH (active and potential, soil adsorption complex characteristics (content of bases, exchangeable cation capacity, base saturation, exchangeable acidity (exchangeable Al and H, total carbon and nitrogen content, and plant available nutrients content (P, K, Ca, Mg. Total macronutrient content (P, K, Ca, Mg was analysed only in holorganic horizons. Results confirmed acidification effects of red oak on the upper forest soil layers such as decreased pH, base content, base saturation, all nutrient contents in total as well as plant-available form and increased soil exchangeable acidity (exchangeable Al in comparison to the sessile oak stands, especially in holorganic horizons and in the uppermost mineral layer (Ah horizon. Northern red oak can be considered as a slightly site-soil degrading species in the studied sites and environmental conditions in comparison to native oak species.

  15. Crecimiento de plántulas y árboles de seis especies de Quercus

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    R. Villar

    2014-01-01

    Full Text Available Los objetivos principales de este trabajo son: a describir algunas características importantes relativas a los rasgos funcionales en plántulas de las especies del género Quercus, b determinar cómo varía la proporción de hoja, tallo y raíz en adultos, y c estimar las tasas de crecimiento relativo(RGR de estas especies para plántulas e individuos adultos. Para ello, usamos los datos de experimentos realizados en plántulas bajo condiciones controladas, del Inventario Forestal Nacional (IFN2 e IFN3 y de las ecuaciones alométricas desarrolladas por Montero et al. (2005. Las especies de Quercus se caracterizan por tener semillas grandes, y las plántulas presentan una baja RGR y área específica foliar (SLA y una alta proporción de raíz (RMR. Uno de los factores más importantes que explican las diferencias en RGR entre las especies de Quercus (tanto en plántulas como en adultos es la diferencia en SLA. Considerando los datos de biomasa de árboles, se observa que la proporción de hoja (LMR y de raíz (RMR disminuye con el tamaño, mientras que la proporción de tallo (SMR aumenta con éste. Si consideramos un árbol medio de 20 cm de diámetro de tronco, los valores de LMR son de sólo 1-5 % y los de SMR van del 50 al 80 %. Considerando los datos del IFN, dentro de cada especie existe una gran variación en RGR. Aun así, cuando se comparan las RGR de las plántulas con los adultos se observa una relación significativa y positiva. Uno de los factores que afectó significativamente a RGR fue el tamaño del árbol, de forma que árboles de mayor tamaño crecían más lentamente.

  16. Characterizing water use strategies of Acer saccharum, Liriodendron tulipifera, and Quercus spp. during a severe drought

    Science.gov (United States)

    Yi, K.; Novick, K. A.; Dragoni, D.; Moore, W.; Roman, D. T.

    2014-12-01

    In many areas, drought is expected to occur more frequently and intensely in the future due to climate change; however, drought effects on ecosystem-scale fluxes in diverse forests will reflect the diversity of water use strategies among the dominant tree species. For three years (2011-2013) that included a severe drought event (in 2012), we measured the sap flow densities along the sapwood profiles (four radial depths: 1, 2, 3, 4 cm) in Acer saccharum, Liriodendron tulipifera, and Quercus spp. using the compensation heat pulse technique at the Morgan-Monroe State Forest (Indiana, USA). Sap flow velocity varies along the radial profile of the stem, and thus characterizing its pattern is important for estimating whole tree sap flow, and for characterizing the extent to which water stress alters the radial pattern of flow. We also focused on the nocturnal sap flow, which may be used to replenish stored water depleted during the daytime, in order to assess the extent to which the three species rely on hydraulic capacitance to cope with water stress. Sap flow densities along the sapwood profile of all three species tended to increase toward the cambium under moderate climate, while the tendency was reversed under severe drought. This shift may indicate greater reliance on stored water in the inner sapwood or cavitation of outer sapwood during the drought. It was also noticeable that Quercus spp. showed lower maximum sap flow density and narrower range (1.5 - 4.6 cm h-1) than other species (A. saccharum: 1.0 - 20.8 cm h-1, L. tulipifera: drought year for A. saccharum (0.140.01 in 2011 and 0.200.01 in 2013 vs. 0.290.01 in 2012) and L. tulipifera (0.140.00 in 2011 and 0.090.01 in 2013 vs. 0.300.01 in 2012), while Quercus spp. didn't show a significant difference between moderate and drought years. This may be due to the replenishment of stored water of A. saccharum and L. tulipifera that was lost during the daytime. These results implied different strategies among the

  17. Hepatoprotective effects of Quercus infectoria gall extract against carbon tetrachloride treated liver injury in rats

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    Gaurav Lodhi

    2012-08-01

    Full Text Available Summary. In the present study, galls of Quercus infectoria possessing potent antioxidant and antiinflammatory properties were evaluated for their hepatoprotective effect against carbon tetrachloride (CCl4 induced hepatotoxicity in rats. Subcutaneous injection of CCl4, administered twice a week, produced a marked elevation in the serum levels of aspartate transaminase (AST, alanine transaminase (ALT and tumor necrosis factor alpha (TNF-α. Histological analysis of the liver of these rats revealed marked necro-inflammatory changes that were associated with increase in the levels of TBARS, PGE2 and catalase and decrease in the levels of glutathione (GSH, superoxide dismutase (SOD and glutathione peroxidase (GPx. Daily oral administration of aqueous ethanolic extract of Quercus infectoria galls at 200, 400 and 600 mg/kg doses produced a dose dependent reduction in the serum levels of liver enzymes and inflammatory mediators and attenuated the necroinflammatory changes in the liver. The QIE treatment also normalized various biochemical parameters of oxidative stress. Our study shows that the hepatoprotective effects of QIE and silymarin were comparable and suggests that QIE could be used as a hepatoprotective agent. Industrial relevance. Research in traditional medicine has lead to the development of many modern medicines. In recent times, focus on plants research has increased all over the world and a large body of evidence has been collected to show immense potential of medicinal plants used in various traditional systems. It is very interesting to note that there is no drug available in the modern system of medicine for treating hepatic disorders; only certain herbal preparations are available to treat this quite vulnerable disease. The situation/background thus explained above warrants for developing a safe, effective and scientifically validated hepatoprotective agent taking lead from traditional medicine, which is affordable for the rural poor

  18. [Age structure and dynamics of Quercus wutaishanica population in Lingkong Mountain of Shanxi Province, China].

    Science.gov (United States)

    Zhang, Jie; Shangguan, Tie-Liang; Duan, Yi-Hao; Guo, Wei; Liu, Wei-Hua; Guo, Dong-Gang

    2014-11-01

    Using the plant survivorship theory, the age structure, and the relationship between tree height and diameter (DBH) of Quercus wutaishanica population in Lingkong Mountain were analyzed, and the static life table was compiled and the survival curve plotted. The shuttle shape in age structure of Q. wutaishanica population suggested its temporal stability. The linear regression significantly fitted the positive correlation between tree height and DBH. The maximal life expectancy was observed among the trees beyond the age of the highest mortality and coincided with the lowest point of mortality density, suggesting the strong vitality of the seedlings and young trees that survived in the natural selection and intraspecific competition. The population stability of the Q. wutaishanica population was characterized by the Deevey-II of the survival curve. The dynamic pattern was characterized by the recession in the early phase, growth in the intermediate phase, and stability in the latter phase.

  19. Rapid Synthesis of Gold Nanoparticles from Quercus incana and Their Antimicrobial Potential against Human Pathogens

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    Rizwana Sarwar

    2017-01-01

    Full Text Available In current study, bioreduction of tetrachloroauric acid (HAuCl4·3H2O was carried out using leaves extract of Quercus incana for nanoparticle synthesis. The nanoparticles were characterized by ultraviolet visible spectrum (UV, Fourier-transform infrared (FT-IR, and transmission electron microscopy (TEM analysis. The gold nanoparticles (GNPs were generally clumpy agglomerates of polydispersed particles, with an average size in the range 5.5–10 nm. The Gas chromatography–mass spectrometry (GC–MS qualitative analysis and FT-IR data supported the presence of bioactive compounds, which are responsible for the metal reduction and nanoparticles stabilization. The biocompatibility of synthesized GNPs was evaluated via antibacterial activity by using human bacterial pathogens. The results showed that synthesized GNPs showed enhanced antibacterial activity against all bacterial pathogens.

  20. Rotation planar extraction and rotation planar chromatography of oak (Quercus robur L.) bark.

    Science.gov (United States)

    Vovk, Irena; Simonovska, Breda; Andrensek, Samo; Vuorela, Heikki; Vuorela, Pia

    2003-04-04

    The versatile novel instrument for rotation planar extraction and rotation planar chromatography was exploited for the investigation of oak bark (Quercus robur L.). The same instrument enabled extraction of the bark, analytical proof of (+)-catechin directly in the crude extract and also its fractionation. Additionally, epimeric flavan-3-ols, (+)-catechin and (-)-epicatechin were separated by analytical ultra-micro rotation planar chromatography on cellulose plates with pure water as developing solvent. A comparison of the extraction of oak bark with 80% aqueous methanol by rotation planar extraction and medium pressure solid-liquid extraction was carried out and both techniques were shown to be suitable for the efficient extraction of oak bark. The raw extracts and fractions on thin-layer chromatography showed many compounds that possessed antioxidant activity after spraying with 1,1-diphenyl-2-picrylhydrazyl. Rotation planar fractionation of 840 mg of crude oak bark extract on silica gel gave 6.7 mg of pure (+)-catechin in one run.

  1. Dalechampii oak (Quercus dalechampii Ten., an important host plant for folivorous lepidoptera larvae

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    Kulfan, M.

    2013-06-01

    Full Text Available We conducted a structured analysis of lepidoptera larvae taxocenoses living in leaf bearing crowns of Dalechampii oak (Quercus dalechampii Ten. in nine study plots in the Malé Karpaty Mountains (Central Europe. The differences between lepidoptera taxocenoses in individual oak stands were analyzed. A total of 96 species and 2,140 individuals were found. Species abundance peaked in May, while number of species and species diversity reached the highest values from April to May and from April to June, respectively. Abundance showed two notable peaks in flush feeders and in late summer feeders. Lepidoptera taxocenosis in the study plot Horný háj (isolated forest, high density of ants differed significantly from all other taxocenoses according to Sörensen’s index of species similarity, species diversity, analysis of similarity on the basis of permutation and pairwise tests (ANOSIM, seasonal variability of species composition, and NMDS ordination.

  2. Larvicidal activity of oak Quercus infectoria Oliv. (Fagaceae) gall extracts against Anopheles stephensi Liston.

    Science.gov (United States)

    Aivazi, Ali-Ashraf; Vijayan, V A

    2009-06-01

    There is a growing interest in the use of botanical insecticides to reduce the use of synthetic pesticides in order to avoid environmental side effects. Anopheles stephensi is the primary vector of urban malaria, an endemic disease in India. So, an effort to assay An. stephensi larvae with gall extracts of Quercus infectoria was made under laboratory conditions at Mysore. Ethyl-acetate extract was found to be the most effective of all the five extracts tested for larvicidal activity against the fourth instar larvae, with LC(50) of 116.92 ppm followed by gallotannin, n-butanol, acetone, and methanol with LC(50) values of 124.62, 174.76, 299.26, and 364.61 ppm, respectively. The efficacy in killing mosquito larvae may make this plant promising for the development of new botanical larvicide.

  3. QUERCUS ROBUR, Q. CERRIS AND Q. PETRAEA AS HOT SPOTS OF BIODIVERSITY

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    Ecaterina FODOR

    2016-12-01

    Full Text Available Three different bipartite networks (pathogenic, ectomycorrhizal and galling insects established by Quercus robur L., Q. cerris L. and Q. petraea (Matt. Liebl. were merged in order to investigate the topological properties of the complex network, shading light on how biodiversity was organized through complex interactions. The complex network contains 290 species – 137 are pathogens (parasitic interaction, 72 are mycorrhizal fungi (mutualists and 81 species of galling insects (herbivores. Most relevant network descriptors, connectivity, nestedness and modularity were analyzed. The main network and subnetworks displayed different behaviors in terms of topological properties, three of four networks showing significant modularity (galling insects network was marginally significant in what regards modularity. High connectivity and different degrees of nestedness characterized all networks. Clustering and Non Metric Multidimensional scaling refined the information provided by network analysis showing that networks occupy distant positions in ordination space and there are differences in terms of resemblance patterns.

  4. Symptoms of the naturalisation of the Turkey oak (Quercus cerris L. in Polish forests

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    Danielewicz Władysław

    2016-09-01

    Full Text Available The Turkey oak (Quercus cerris L., the natural range of which embraces southern Europe and Asia Minor, belongs to trees rarely introduced into Polish forests. Tree stands where it appears, established before the Second World War, can be found in some 20 localities, mostly in the western part of the country. Because this species is capable of a natural renewal in a woodland environment, a research was made to find in what conditions and how far it undergoes spontaneous naturalisation. Three study sites were chosen in the forests of central Wielkopolska. An inventory was made of mature stands of the Turkey oak and its generative renewal. Plant communities in which the young generation of Q. cerris usually appears were characterised. It was found that self-sown seedlings of this species grew at a distance of up to 2,500 m from parent trees. The highest number and the greatest density of specimens of the secondary generation of the Turkey oak were found at ‘Racot’, which is a 100-hectare, mid-field woodland island where mesotrophic habitats predominate and where about 50% of the area is occupied by communities with manmade pine tree stands. At all sites, Q. cerris penetrates primarily this type of deformed phytocoenoses, developing mostly on former farmland. It has become a permanent component of the underbrush and undergrowth in them, and in some places, it also makes up the tree layer. It was observed that in the study area, it penetrated the woodland environment much more effectively than Quercus rubra, considered an invasive species. The expansion of the Turkey oak in several of the examined localities can be regarded as a basic manifestation of its naturalisation in places where there are phytocoenoses with pine stands in broad-leaf forest habitats in the neighbourhood of parent trees.

  5. Nomenclatura popular de Quercus (Fagaceae: en los valles meridionales de Cantabria (España

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    Pardo de Santayana, Manuel

    2002-06-01

    Full Text Available A survey of the Ethnotaxonomy and Ethnonomenclature of southern Cantabria Quercus (Q- faginea subsp. faginea, Q. ilex subsp. ilex, Q. petraea, Q. pyrenaica, Q. robur is presented. An extensive vocabulary associated with these popular species has been compiled. The analysis of this lexicón shows the richness and complexity of folk plant taxonomy and nomenclature. In total 28 vernacular ñames, which are different forms of 12 principal lexemes, have been compiled. Maps with the geographical distribution of the ñames let us delimit lingüistical áreas. An analysis of this rich lexicón is also presented. The meaning of the ñames, often polisemic, theiretymologies and geographical distribution is studied.Se presenta un estudio sobre la etnotaxonomía y etnonomenclatura de los Quercus (Q. faginea subsp. faginea, Q. ilex subsp. ilex, Q. petraea, Q. pyrenaica, Q. robar que viven en el S de Cantabria. Se ha desarrollado un abundante léxico en tomo a estas especies tan cotidianas, que sirve de ejemplo para estudiar la complejidad y riqueza de la nomenclatura popular. Se han recopilado 28 nombres vernáculos, variantes de 12 lexemas principales. Se han realizado mapas de distribución de los nombres recopilados que permiten delimitar zonas lingüísticas. Además se presenta un análisis de este rico léxico en el que se hace hincapié en su significado, muchas veces polisémico, etimología y distribución geográfica.

  6. Considerations for Sustainable Biomass Production in Quercus-Dominated Forest Ecosystems

    Science.gov (United States)

    Bruckman, Viktor; Yan, Shuai; Hochbichler, Eduard

    2013-04-01

    Our current energy system is mainly based on carbon (C) intensive metabolisms, resulting in great effects on the earth's biosphere. The majority of the energy sources are fossil (crude oil, coal, natural gas) and release CO2 in the combustion (oxidation) process which takes place during utilization of the energy. C released to the atmosphere was once sequestered by biomass over a time span of millions of years and is now being released back into the atmosphere within a period of just decades. In the context of green and CO2 neutral Energy, there is an on-going debate regarding the potentials of obtaining biomass from forests on multiple scales, from stand to international levels. Especially in the context of energy, it is highlighted that biomass is an entirely CO2 neutral feedstock since the carbon stored in wood originates from the atmospheric CO2 pool and it was taken up during plant growth. It needs systems approaches in order to justify this statement and ensure sustainability covering the whole life-cycle from biomass production to (bio)energy consumption. There are a number of Quercus woodland management systems focussing solely on woody biomass production for energetic utilization or a combination with traditional forestry and high quality timber production for trades and industry. They have often developed regionally as a consequence of specific demands and local production capacities, which are mainly driven by environmental factors such as climate and soil properties. We assessed the nutritional status of a common Quercus-dominated forest ecosystem in northern Austria, where we compared biomass- with belowground C and nutrient pools in order to identify potential site limits if the management shifts towards systems with a higher level of nutrient extraction. Heterogeneity of soils, and soil processes are considered, as well as other, growth-limiting factors (e.g. precipitation) and species-specific metabolisms and element translocation.

  7. High Genetic Differentiation among European White Oak Species (Quercus spp. at a Dehydrin Gene

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    Iacob CRĂCIUNESC

    2015-12-01

    Full Text Available Dehydryn genes are involved in plant response to environmental stress and may be useful to examine functional diversity in relation to adaptive variation. Recently, a dehydrin gene (DHN3 was isolated in Quercus petraea and showed little differentiation between populations of the same species in an altitudinal transect. In the present study, inter- and intraspecific differentiation patterns in closely related and interfertile oaks were investigated for the first time at the DHN3 locus. A four-oak-species stand (Quercus frainetto Ten., Q. petraea (Matt. Liebl., Q. pubescens Willd., Q. robur L. and two populations for each of five white oak species (Q. frainetto Ten., Q. petraea (Matt. Liebl., Q. pubescens Willd., Q. robur L. and Q. pedunculiflora K. Koch were analyzed. Three alleles shared by all five oak species were observed. However, only two alleles were present in each population, but with different frequencies according to the species. At population level, all interspecific pairs of populations showed significant differentiation, except for pure Q. robur and Q. pedunculiflora populations. In contrast, no significant differentiation (p > 0.05 was found among conspecific populations. The DHN3 locus proved to be very useful to differentiate Q. frainetto and Q. pubescens from Q. pedunculiflora (FST = 0.914 and 0.660, respectively and Q. robur (FST = 0.858 and 0.633, respectively. As expected, the lowest level of differentiation was detected between the most closely related species, Q. robur and Q. pedunculiflora (FST = 0.020. Our results suggest that DHN3 can be an important genetic marker for differentiating among European white oak species.

  8. Antibacterial effects of Quercus Brantii fruits and Stachys lavandulifolia methanol extracts on imipenemase-type metallo-beta lactamase-producing Pseudomonas aeruginosa

    National Research Council Canada - National Science Library

    F. Shahi; A. Hashemi; Kh. Abdolmaleki; Z. Shahi; Sh. Amraei; H. Goudarzi; F. Fallah; S. Khoshnood

    2017-01-01

    .... The aim of the present study was to evaluate the antibacterial activity of Stachys lavandulifolia and Quercus brantii on the IMP-type metallo-beta-lactamase-producing Pseudomonas aeruginosa. Methods...

  9. Removal of acorns of the alien oak Quercus rubra on the ground by scatter-hoarding animals in Belgian forests

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    Merceron, NR.

    2017-01-01

    Full Text Available Description of the subject. Quercus rubra L. is considered an invasive species in several European countries. However, little is known about its dispersal in the introduced range. Objectives. We investigated the significance of animal dispersal of Q. rubra acorns on the ground by vertebrates in its introduced range, and identified the animal species involved. Method. During two consecutive autumns, the removal of acorns from Q. rubra and from a native oak was assessed weekly in forest sites in Belgium. We used automated detection camera traps to identify the animals that removed acorns. Results. Quercus rubra acorns were removed by wood mice (Apodemus sylvaticus L., red squirrels (Sciurus vulgaris L., rats (Rattus sp., and wild boars (Sus scrofa L.. The two former are scatter-hoarding rodents and can be considered potential dispersers. Conclusions. Dispersal of Q. rubra acorns in Western Europe by scatter-hoarding animals may help the species increasingly colonize forest ecosystems.

  10. The ecosystem of the Yahudia Nature Reserve with emphasis on dynamics of germination and development of Quercus ithaburensis Decne

    OpenAIRE

    Kaplan, Y.

    1984-01-01

    6 main subjects connected with the ecology of the Yahudia Forest Reserve are discussed in this paper, following a general survey of the history of nature conservation in Israel against the background of the neighbouring countries. We have described the physical and historical background of the Yahudia Forest; the inventory of vertebrates; the inventory of vegetation, analysing composition and mapping; described and researched Quercus ithaburensis from various aspects, with emphasis on phenolo...

  11. First Report of the Winter Moth Operophtera brumata on Quercus canariensis and Q. afares in North West of Tunisia

    OpenAIRE

    Yaussra Mannai; Olfa Ezzine; Said Nouira; Mohamed Lahbib Ben Jamâa

    2015-01-01

    Operophtera brumata is a newly detected moth in Tunisia. It is considered the most important leaffeeding pest infesting fruit trees and deciduous forests in northern Europe. A recent outbreak of the winter moths was observed between 2009 and 2014 in oak forest in the North West of Tunisia with a peak density in 2010-2011. O. brumata was observed on totally defoliated Quercus canariensis and Q. afares. In this paper, we present a first report of this pest.

  12. Propagación in vitro de encinos mexicanos (Quercus spp.

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    Jose Silvestre Delgadillo-Díaz de León

    2015-08-01

    Full Text Available Con el fin de ofrecer una alternativa a los sistemas convencionales de propagación, se desarrolló un protocolo para la multiplicación in vitro de cuatro especies mexicanas deQuercus, las cuales son explotadas para la producción de madera y carbón y están actualmente amenazadas. Se describe la inducción de brotes múltiples a partir de embriones cigóticos deQuercus castanea,Q. eduardii,Q. resinosayQ. rugosacultivados en medio de Murashige y Skoo-genriquecido con 6-bencilaminopurina (BA o cinetina. Los resultados mostraron que ambas citocininas afectaron la regeneración de brotes, donde la BA mostró la mayor efi ciencia. La mayor frecuencia de proliferación de brotes se observó enQ. castaneayQ. eduardii(91.7%, dando promedios de 6.3 y 6.5 brotes por explante al utilizar 3.0 y 4.0 mg l-1de BA, respectivamente. ParaQ. resinosa, la mejor respuesta fue obtenida con BA a 3.0 mg l-1produciendo 3.8 brotes por explante. Finalmente,Q. rugosaprodujo 3.6 brotes por explante con 1.0 mg l-1de BA. Los brotes fueron separados de las plántulas y transferidos a un medio basal a la mitad de su concentración enriquecido con 10.0 mg l-1de ac. indolbutírico por dos a cinco días, y luego transferidos a medio a la mitad de su concentración para su enraizamiento. Bajo estas condiciones, el 100, 100, 66.7 y 83.3% de los brotes deQ. castanea,Q. eduardii,Q. resinosayQ. rugosageneraron raíces, respectivamente. Las plántulas fueron aclimatadas a suelo en condiciones de invernadero de manera exitosa con frecuencias de sobrevivencia de 80% paraQ. castanea, 83.3% paraQ. eduardii, 73.3% paraQ. resinosa, y 70.0% paraQ. rugosa. Este método de propagación in vitro puede contribuir a la producción de plantas con fines de reforestación apoyando así la conservación y uso racional de estas especies.

  13. Natural production of Tuber aestivum in central Spain: Pinus spp. versus Quercus spp. brûlés

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    Luis G. Garcia-Montero

    2014-08-01

    Full Text Available Aim of study: Tuber aestivum is the most widespread edible truffle, with increasing commercial interest. This species can produce carpophores with conifer hosts, in contrast with the inability of Pinus spp. to induce fruiting in other truffle species such as Tuber melanosporum. Therefore the objective is to compare the characteristics and carpophore production of T. aestivum brûlés associated with Pinus spp. versus Quercus spp.Area of study: We studied the natural habitats of T. aestivum in the Alto Tajo Nature Reserve in central Spain.Material and methods: During 5 years, we monitored the production of carpophores and brûlé size of 145 T. aestivum brûlés associated with Pinus nigra subsp. salzmanni and P. sylvestris and Quercus ilex subsp. ballota and Q. faginea hosts. Statistical treatment was performed using the Statistica Program v. 6.Main Results: The size of brûlés associated with Pinus was significantly smaller than that of brûlés associated with Quercus. However, carpophore production per brûlé, and especially for brûlés of similar size, was greater when the host plant was a pine. After accounting for brûlé size, the production of brûlés associated with Pinus spp. was 2.23 (95% CI, between 1.35 and 3.69 and 1.61 (95% CI, between 1.02 and 2.54 times greater than the production of brûlés associated with Quercus faginea and Q. ilex subsp. ballota, respectively.Research highlights: The considerable ability of Pinus nigra subsp. salzmanni and P. sylvestris to form effective brûlés and to produce carpophores of Tuber aestivum in natural conditions was clearly demonstrated, and suggest that those species can be of use in the culture of T. aestivum.Key words: Summer truffle; Tuber aestivum; truffle culture; truffle ecology; Pinus spp.; Quercus spp.

  14. In vitro antibacterial activity of Quercus infectoria gall extracts against multidrug resistant bacteria.

    Science.gov (United States)

    Wan Nor Amilah, W A W; Masrah, M; Hasmah, A; Noor Izani, N J

    2014-12-01

    Antimicrobial activities of plants have long been evaluated for their promising use as antimicrobial agent and in minimizing the unwanted resistance effects of microorganisms. The study was conducted to evaluate the antibacterial activity of Quercus infectoria gall crude extracts against multidrug resistant (MDR) bacteria in vitro. The screening test was determined by disc diffusion technique using sterile filter paper discs impregnated with 1 mg/ disc (50 mg/ml) aqueous and ethanol extracts of Q. infectoria galls tested on five selected MDR bacterial strains. The minimum inhibitory concentration (MIC) was determined using the twofold serial micro dilution technique at concentration ranging from 5.00 mg/ml to 0.01 mg/ml. The minimum bactericidal concentration (MBC) was determined by sub culturing the microtitre wells showing no turbidity on the agar plate to obtain the MBC value. Both extracts showed substantial inhibitory effects against methicillin resistant coagulase negative Staphylococcus (MRCoNS) and methicillin resistant Staphylococcus aureus (MRSA). A slightly reduced inhibitory zone diameter was observed with MDR Acinetobacter sp. while no inhibitory effect was displayed among the extended spectrum beta lactamases (ESBL) K. pneumoniae and ESBL E. coli isolates. A significant difference in the zone sizes between both extracts was only observed in MRSA (p antibacterial activities and may be considered as a potentially good source of antimicrobial agent especially against MDR Gram positive bacteria.

  15. Scaling-up method for stand water consumption of Quercus variabilis water conservation forest

    Institute of Scientific and Technical Information of China (English)

    WANG Huatian; XING Lifeng; MA Lüyi; SUN Pengsen

    2006-01-01

    Single tree's sapwood scattering style and diurnal water consumption rhythm for different diameter classes were studied in a 48-year-old Quercus variabilis stand,water protection forest in Beijing.Results showed that the tree's sapwood area was closely related to diameter at breast height (DBH).Single tree's daily water consumption ascended as DBH and sapwood area increased.Daily water consumption of different diameter classes in September ascended steeply in the early morning and reached the peak around 11:00,and then descended slowly to the valley at 18:00.The course of daily accumulated water consumption was in accordance with a typical Richards model (R=0.985,8).Parameters of diameter-time equation for scal ing-up can be achieved by parameter-recovering method in the gradient of all diameter classes and at any time of a day,characteristic parameters of the course of daily stand water consumption were calculated from a modulated Richards equation derivative:Wdltl = (-7.147 + 1.174dl )[1- (-3,025.937 +di2.175)1/e(-0.01 1tj) ]1-di0.242

  16. Morphological variation of Quercus Iiaotungensis leaves in Lingkong Mountain,Shanxi Province

    Institute of Scientific and Technical Information of China (English)

    LI Mei; HAN Hairong; KANG Fengfeng; MA Qinyan

    2007-01-01

    In order to study variation of morphological traits and the influencing factors of natural populations of Quercus liaotungensis Koidz.in Lingkong Mountain Nature Reserve of Shanxi region,five populations were included,and 24 morphological traits of leaf and apical bud were investigated.The analysis of variance showed that variation of all the morphological traits within population were significant,whereas significant difference existed in five property indices among populations (α = 0.05),which resulted from genetic and environmental factors.The results revealed that direction and degree of slope,average diameter at breast height in populations,and population density were the main influencing factors.Intrapopulation variation mainly contributed to morphological variation,and the phenotypic differentiation coefficient was 13.31%,which indicated low level of differentiation.But several characteristics exhibited high differentiation level,such as width of the tooth of leaf base (25.99%) and the middle apical bud (25.23%).The morphological indices,including the tooth of leaf base,leaf tip,petiole,and leaf area were precarious and changed a lot within population,which arose from the variation of individual's development.However,only two morphological indices,the middle apical bud and the tooth of leaf base,are unstable,which indicates the extensive influence of environmental factors.

  17. FENOLOGÍA DEL ROBLE (Quercus humboldtii Bonpland EN POPAYÁN (CAUCA, COLOMBIA

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    CRISTIAN ANDRÉS PÉREZ L.

    Full Text Available Se realizó un registro fenológico del roble Quercus humboldtii Bonpland entre marzo del 2010 y marzo de 2011 - en el municipio de Popayán (Cauca, Colombia. La producción de flores femeninas y frutos jóvenes se presentó entre finales de marzo y principios de abril, correlacionándose positivamente estas dos fenofases durante todo el año con la temperatura (r=0,64 y r=0,44, respectivamente y en los inicios de estas dos fenofases se correlacionó con la precipitación (r=0,69 y r=0,92 respectivamente. Los frutos maduros aparecieron en mayo, aunque su cantidad se redujo hacia el final del año 2010 por el aborto de frutos en los meses anteriores. La actividad vegetativa se caracterizó por la presencia permanente de hojas nuevas, maduras, amarillas, sobremaduras y caída de follaje. Sin embargo, en agosto, debido al aumento significativo de la temperatura y a la disminución en la precipitación, se observó en los árboles caída de follaje, disminución de hojas maduras y producción de hojas nuevas.

  18. The effect of Quercus brantii gall extract on burn wound healing in rat

    Science.gov (United States)

    Haghdoost, Faraidoon; Baradaran Mahdavi, Mohammad Mehdi; Zolfaghari, Behzad; Sanei, Mohammad Hossein; Najafi, Somaye; Zandifar, Alireza; Manouchehri, Navid; Javanmard, Shaghayegh Haghjooy

    2016-01-01

    Objective(s): The aim of the present study was to evaluate the effect of Quercus brantii galls extract on the rat skin burn wound healing. Materials and Methods: Ethanol extract of the galls of Q. brantii was used to treat the induced burn wounds on the back of 32 Wistar rats divided into 4 groups. The groups were treated by placebo, 1%, 2% and 4% concentration gall extract gels for 14 days and the efficacy of treatment was assessed based on reduction of burn wound area, as well as histological and molecular characteristics. Results: The mean wound surface in the 14th day, in all groups treated by Q. brantii gall extracts were larger than control group and the differences were statistically significant (P=0.043). The mean histological wound healing scores were not statistically different. Analysis of nitric oxide and platelet derived growth factor concentration in wound fluids in the 5th day of study showed that there was not any significant difference between groups (P=0.468 and 0.312 respectively). Fibroblast growth factor (bFGF) concentration in the wound fluids, was significantly higher in group treated with 1% gall extract gel in comparison to the control group (P=0.026). Conclusion: Our results could not prove the significant positive effect of Q. brantii galls extract on the burning wound healing. More studies with more groups treated with different doses of the Q. brantii extract are recommended. PMID:27872712

  19. [Predicting the impact of global warming on the geographical distribution pattern of Quercus variabilis in China].

    Science.gov (United States)

    Li, Yao; Zhang, Xing-wang; Fang, Yan-ming

    2014-12-01

    The geographical distribution of Quercus variabilis in China with its climate characteristics was analyzed based on DIVA-GIS which was also used to estimate the response of future potential distribution to global warming by Bioclim and Domain models. Analysis results showed the geographical distribution of Q. variabilis could be divided into 7 subregions: Henduan Mountains, Yunnan-Guizhou Plateau, North China, East China, Liaodong-Shandong Peninsula, Taiwan Island, and Qinling-Daba Mountains. These subregions are across 7 temperature zones, 2 moisture regions and 17 climatic subregions, including 8 climate types. The modern abundance center of Q. variabilis is Qinling, Daba and Funiu mountains. The condition of mean annual temperature 7.5-19.8 degrees C annual precipitation 471-1511 mm, is suitable for Q. variabilis. Areas under the receiver operating characteristic curve (AUC values), of Domain and Boiclim models were 0.910, 0.779; the former predicted that the potential regions of high suitability for Q. variabilis are Qinling, Daba, Funiu, Tongbai, and Dabie mountains, eastern and western Yunnan-Guizhou Plateau, hills of southern Jiangsu and Anhui, part of the mountains in North China. Global warming might lead to the shrinking in suitable region and retreating from the south for Q. variabilis.

  20. COENOTICAL CHAINS OF ACER PLATANOIDES AND QUERCUS ROBUR IN THE FORESTS OF NOVGOROD-SEVERSKOYE POLESYE

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    Skliar V. G.

    2012-12-01

    Full Text Available We summarized information on association of small undergrowth of Norway maple (Acer platanoides L. and English oak (Quercus robur L. under the canopy of the forest with plants that form the grass-shrub layer within Novgorod-Severskoye Polesye. We founded that the association at certain extent depends on the type of population behavior of undergrowth and grasses. Small undergrowth of A. platanoides being the tolerant species according to the type of population behavior demonstrates negative association with the herbs that have high competitive ability. The pattern of association of A. platanoides with tolerant species depends on their vegetative mobility: the maple has positive association with species with no vegetative mobility and positive and negative association with species characterized by high extent of vegetative mobility. The undergrowth of Q. robur which is the competitive species due to population behavior shows positive association with the herbs that have high competitive ability. We estimated the coenotic parameters that are required for successful resumption of maple and oak in the region of research. We also shown that coenotic optimum for A. platanoides corresponds to the environment with weak intensity of competition in the living soil cover with thin grass layer and density of coverage does not exceed 50%. Q. robur has coenotic optimum among habitats in the herbaceous layer with domination of green moss and (or Convallaria majalis L., Fragaria vesca L. with no grains and density of coverage in living ground cover not more than 60%.

  1. Drought changes the dynamics of trace element accumulation in a Mediterranean Quercus ilex forest

    Energy Technology Data Exchange (ETDEWEB)

    Sardans, J. [Unitat d' Ecofisiologia CSIC-CEAB-CREAF, CREAF - Centre de Recerca Ecologica d' Aplicacions Forestals, Edifici C, Universitat Autonoma Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: j.sardans@creaf.uab.cat; Penuelas, J. [Unitat d' Ecofisiologia CSIC-CEAB-CREAF, CREAF, Centre de Recerca Ecologica d' Aplicacions Forestals, Edifici C, Universitat Autonoma Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2007-06-15

    We conducted a field drought manipulation experiment in an evergreen oak Mediterranean forest from 1999 to 2005 to investigate the effects of the increased drought predicted for the next decades on the accumulation of trace elements that can be toxic for animals, in stand biomass, litter and soil. Drought increased concentrations of As, Cd, Ni, Pb and Cr in roots of the dominant tree species, Quercus ilex, and leaf Cd concentrations in Arbutus unedo and of Phillyrea latifolia codominant shrubs. The increased concentration of As and Cd can aggravate the toxic capacity of those two elements, which are already next or within the levels that have been shown to be toxic for herbivores. The study also showed a great reduction in Pb biomass content (100-135 g ha{sup -1}) during the studied period (1999-2005) showing the effectiveness of the law that prohibited leaded fuel after 2001. The results also indicate that drought increases the exportation of some trace elements to continental waters. - Drought increased biomass concentrations of As and Cd and favors exportation of some trace elements to continental waters in a Mediterranean forest.

  2. PAHs in decaying Quercus ilex leaf litter: mutual effects on litter decomposition and PAH dynamics.

    Science.gov (United States)

    De Nicola, F; Baldantoni, D; Alfani, A

    2014-11-01

    The investigation of the relationships between litter decomposition and polycyclic aromatic hydrocarbons (PAHs) is important to shed light not only on the effects of these pollutants on fundamental ecosystem processes, such as litter decomposition, but also on the degradation of these pollutants by soil microbial community. This allows to understand the effect of atmospheric PAH contamination on soil PAH content via litterfall. At this aim, we studied mass and PAH dynamics of Quercus ilex leaf litters collected from urban, industrial and remote sites, incubated in mesocosms under controlled conditions for 361d. The results highlighted a litter decomposition rate of leaves sampled in urban>industrial>remote sites; the faster decomposition of litter of the urban site is also related to the low C/N ratio of the leaves. The PAHs showed concentrations at the beginning of the incubation of 887, 650 and 143 ng g(-1)d.w., respectively in leaf litters from urban, industrial and remote sites. The PAHs in litter decreased along the time, with the same trend observed for mass litter, showing the highest decrease at 361 d for the urban leaf litter. Anyway, PAH dynamics in all the litters exhibited two phases of loss, separated by a PAH increase observed at 246 d and mainly linked to benzo[e]pyrene.

  3. Screening of Quercus infectoria gall extracts as anti-bacterial agents against dental pathogens.

    Science.gov (United States)

    Vermani, Archa

    2009-01-01

    A number of bacteria have now become antibiotic-resistant. This increases the importance of ayurvedic drugs. We report, here, the activity of different extracts (petroleum ether, chloroform, methanol and water) of Quercus infectoria galls against dental pathogens -- Streptococcus mutans, Streptococcus salivarius, Staphylococcus aureus, Lactobacillus acidophilus (designated) and Streptococcus sanguis (isolated). The cup-plate method was used in anti-bacterial activity of the extracts at concentration of 200 mg/ml against dental pathogens. Minimum inhibitory concentration (MIC) values of most effective extracts against the most susceptible bacteria were determined using a two-fold serial micro dilution method. Methanolic extract showed maximum anti-bacterial activity against all the bacteria. The most susceptible bacteria were S. sanguis followed by S. aureus, S. mutans, S. salivarius and L. acidophilus. The MIC values showed that methanolic extract was more effective than water extract. The plant has the potential to generate herbal metabolites. The crude extracts demonstrating anti-dental caries activity could result in the discovery of new chemical classes of antibiotics. These chemical classes of antibiotics could serve as selective agents for the maintenance of human health and provide bio-chemical tools for the study of infectious diseases.

  4. A comparative analysis of stomata and leaf trichome characteristics in Quercus robur L. genotypes

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    Nikolić Nataša P.

    2003-01-01

    Full Text Available The objective of this study was to determine genotype variability of leaf trichome and stoma characteristics. Leaves were sampled from seventeen pedunculate oak (Quercus robur L genotypes originating from clonal seed orchard Banov Brod (Srem, the Vojvodina Province. The pedunculate oak has hypostomatal leaves. Statistically significant differences were found for the dimensions and density of stomata. Genotype variability of stomatal dimensions was less pronounced in comparison with their density (CV = 8.88%. Stomata number ranged from 530 to 791 per mm2 of leaf area; genotypes 18 and 25 could be distinguished from the others for the highest stomata number per leaf unit area, genotype 35 for the lowest number. In all genotypes, only solitary eglandular trichomes were observed on the adaxial leaf surface while both solitary eglandular and uniseriate glandular hairs were present on the abaxial surface. Single glandular trichomes were observed in all genotypes, while some of them were characterized by the presence of two (genotypes 4, 5, 6, 16, 22, 25, 28, 29, 30, 35, 38, 40, and 85 or three (genotypes 16, 25, 35 hairs joined by their basal cells.

  5. A phytosociological analysis of the Quercus coccifera L. stands in south Albania (NE Mediterranean

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    Jasprica Nenad

    2016-06-01

    Full Text Available The results of a phytosociological investigation of the Quercus coccifera L. stands occurring along the Adriatic and Ionian coasts in south Albania are given. The surveyed stands are localized in the Thermo-Mediterranean and Meso-Mediterranean belts. On the basis of literature and unpublished data, Q. coccifera stands extend from the shoreline up to 680 m of altitude, within the Quercetea ilicis vegetation zone. According to numerical analysis, Q. coccifera stands in south Albania can be divided into two broad groups forming macchia of 3–4 m height and low shrublands [0.5–1.5(-2 m] defined primarily by degree of human pressure and altitudes. In addition, relevés from Q. coccifera stands in Albania were differentiated from Croatian and Montenegrin the Fraxino orni-Quercetum cocciferae associations. Conversely, Q. coccifera stands in south Albania share several biological and ecological similarities with those of the eastern Adriatic coast: hemicryptophytes prevailed and the chorological spectrum highlights a clear dominance of the steno-Mediterraneans. With respect to indicator values, an important differentiation from the eastern Adriatic associations was shown only in higher light intensity of the stands in Albania.

  6. Soil development in OSL dated sandy dune substrates under Quercus robur Forest (Netherlands)

    Science.gov (United States)

    van Mourik, J. M.; Nierop, Ir. K.; Verstraten, J. M.

    2009-04-01

    Coastal dune landscapes are very dynamic. The present distribution of vegetation and soil is the result of over 2000 years of natural processes and human management. The initial soil development was controlled by an increase of the organic matter content, which consisted mainly of decomposed roots of grasses (rhizomull), and a decrease of the soil pH to 3-4 by decalcification. This stage was followed by the development of a deciduous forest, which was dominated by Quercus robur. Since 1600 AD, a large part of the deciduous forest that dominated the east side of the coastal dune landscape transferred in expensive residential areas and urbanizations. Nevertheless some parts of the oak forest belt remained. The present forest soils are acid and the controlling soil processes are leaching of sesquioxides and storage of organic matter in mormoder humus forms. The sustainability of ecosystems is closely related to the quality of the humus form, controlling nutrient cycling and water supply. Therefore, improve of knowledge of humus form development and properties is important. We applied soil micromorphology and pyrolysis-gas chromatography/mass spectrometry (GC/MS) to investigate more details of humus form development at two locations (Duivendrift and Hoek van Klaas) in the coastal dune area of the Amsterdamse Waterleidingduinen (near Haarlem, the Netherlands). However, to understand forest soil development, including the organic matter composition in the humus form, the age of the substrate and the forest is required. Therefore, we used tradition techniques as pollen analysis and radiocarbon dating but also the recently introduced optical stimulated luminescence (OSL) dating technique. OSL dating works excellent for aeolian sandy deposits with a high percentage of quartz grains. The OSL age is defined as the time after the last bleaching by solar radiation of mineral grains. Or in other words, the start of a stable period without sand drifting. In the Ah horizons we

  7. Evaluation of Hypoglycemic and Genotoxic Effect of Polyphenolic Bark Extract from Quercus sideroxyla

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    Marcela Soto-García

    2016-01-01

    Full Text Available Quercus sideroxyla is a wood species whose bark has phenolic compound and should be considered to be bioactive; the hypoglycemic and genotoxic properties of Q. sideroxyla bark were evaluated in this study. Total phenolic compound was determined in crude extract (CE and organic extract (OE. The OE has the highest amount of phenols (724.1±12.0 GAE/g. Besides, both CE and OE demonstrated effect over the inhibition of α-amylase in vitro. Hypoglycemic activity was assessed by glucose tolerance curve and the area under curve (UAC; OE showed the highest hypoglycemic activity. In addition, diabetes was induced by streptozotocin (65 mg/kg and the extracts (50 mg/kg were administered for 10 days; OE showed hypoglycemic effect compared with diabetic control and decreased hepatic lipid peroxidation. Acute toxicity and genotoxicity were evaluated in CE; results of acute toxicity did not show any mortality. Besides, the comet assay showed that CE at a dose of 100 mg/kg did not show any genotoxic effect when evaluated at 24 h, whereas it induced slight damage at 200 mg/kg, with the formation of type 1 comets.

  8. [Effects of coat and sowing depth on seed germination and early seedling growth of Quercus wutaishanica].

    Science.gov (United States)

    Yan, Xing-Fui; Qiu, Zhi-Hu; Zhang, Qiang; Zhang, Kao-Wen; Zhou, Yun-Feng

    2014-01-01

    Under shade environment in glasshouse, the effects of seed coat and sowing depth (0, 2, 5, 10 or 15 cm) on seed germination and early seedling growth of Quercus wutaishanica were studied. Seed coat had obvious inhibiting effects on the germination of Q. wutaishanica seeds. The germination percentage of uncoated seeds increased significantly, averagely by 19.4% at different sowing depths. The germination index and vigor index were increased significantly and the germination was speeded in the peeling treatment. The germination percentages of uncoated and coated seeds were the highest at the sowing depth of 2 cm with 78.9% and 62.2%, respectively. The germination index and vigor index were the highest at the sowing depth of 2 cm, while the coefficient of rate of germination were the highest at the sowing depth of 5 cm. Leaf area per seedling and dry mass of seedlings increased significantly in the peeling treatment compared with those in the unpeeling treatment, but specific root length decreased significantly. The shoot height in the peeling and unpeeling treatments were the highest at the sowing depth of 5 cm with 13.8 and 14.2 cm, respectively. With the increasing of sowing depth, the basal stem diameter of seedlings increased, but tap-root length, number of lateral root and maximum of lateral root all decreased. Sowing depth had little influence on dry mass of seedlings.

  9. Nutrient composition and starch characteristics of Quercus glandulifera Bl. seeds from China.

    Science.gov (United States)

    Li, Songnan; Zhou, Yibin; Liu, Mei; Zhang, Yang; Cao, Shengnan

    2015-10-15

    The chemical composition and starch characteristics of acorn (Quercus glandulifera Bl.) were studied. The moisture content of acorn seeds was 7.55%. The crude fat, crude protein, dietary fiber, total ash, and nitrogen-free extract contents of acorn seed were 4.20%, 10.16%, 2.95%, 0.03%, and 82.66%, respectively, on a dry weight basis. Linoleic, oleic, and palmitic were the most predominant fatty acids. UFA:SFA and SFA:MUFA:PUFA ratios were 2.6:1 and 1.25:1.34:1, respectively. The essential amino acid content from acorn seeds was low based on FAO reference values. Acorn seeds were a good source of Fe, Zn, and Mn. The contents of vitamins A and E were 1.40 mg RE/100g and 10.78 mg/100 g, respectively. Starch extracted from acorn seeds had round, triangle, and elliptical morphology with granule size of 3.3-126.2 μm. The ratio between amylose and amylopectin contents was 25.39:72.94. Acorn starch had a typical A-type crystal pattern with 23.53% relative crystallinity. The gelatinization temperature was 66.53 °C and the transition enthalpy was 4.33 J/g.

  10. Conservation Strategies for the Threatened Quercus Semecarpifolia Sm. A Himalayan Timberline Oak

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    Hemlata BISHT

    2011-12-01

    Full Text Available Quercus semecarpifolia Sm. is a temperate, timberline, multipurpose oak species. It plays an important role in the Himalayan ecosystem. Human pressure, predation, short-lived acorns, failure of good seed crop every year, poor regeneration, desiccation, frost sensitivity and climate change may lead to complete extinction of the species in a near future. Immediate attention to conservation and restoration measures of the Himalayan ecosystem, in which this species grows, is required. Thus, an experiment was designed to analyze the role of planting stock and micro-sites for the regeneration of Q. semecarpifolia in-situ. For that purpose, 16 microsites with presence/absence of litter, canopy and sunlight were identified, where seeds/propagules were planted. The presence of litter, canopy and sunlight influenced the seedling production, mainly impairing the processes, leading to the expansion in diameter of the radicle, causing shoot/root emergence. Radicle emergence took place in all the seeds immediately after shedding but only 20% of seedlings recovered; however, when the stored seeds were sown as soon as the emerging radicle attained 10-15cm in length and 2-3cm in diameter, 80% of seedlings were recovered. Surprisingly, after being detached from the seed the swollen radicle acted as a propagule and produced 80% seedlings irrespective of the microsites; however, radicles detached prior to diameter expansion failed to produce seedlings which is a crucial insight for promoting seedling production.

  11. Oak (Quercus Floribunda: A Prominent Indigenous Multipurpose Tree for Carbon Storage and Sequestration Potential

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    K. K. Pandey

    2015-12-01

    Full Text Available A dynamic growth model (CO2FIX has been used for estimating the carbon sequestration potential of Oak (Quercus floribunda, an indigenous multipurpose tree used for timber, fuel wood, fiber and specially fodder in addition to its ability of soil binder. The present study has been carried out in the campus of V.C.S.G. College of Horticulture, U.U.H.F., Bharsar, Pauri Garhwal, Uttarakhand. It is capable of thriving on snow and heavy rainfall condition. CO2FIX was parameterized for a simulation of 100 years respectively. The results indicate that the long term tree biomass accumulated was 120.11 t/ha in above ground and 79.89 t/ha in below ground (Soil Carbon component respectively at the end of simulation period assuming a tree density of 825t/ha (approximately. The net annual carbon sequestration for Oak over the entire simulation period was 1.9 Mg C ha-1 yr -1 (t/ha/yr. Useful for scientific planning and effective implementation of Forestry and Agroforestry developmental programmes at district level as well as at State level for the development of country. For future research work following are few suggestions for better planning and development of State. This type of study can be taken including other parameters/resources such as different trees, different area, and different state and different country as well.

  12. Pedunculate oak forests (Quercus robur L. survey in the Ticino Regional Park (Italy by remote sensing

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    Rossini M

    2007-01-01

    Full Text Available Pedunculate oak forests (Quercus robur L. in the Ticino Regional Park (Italy show sensible damage conditions due to different environmental stresses: insect attacks, summer drought and air pollution. Knowing whether oaks are healthy or stressed can provide useful information in order to conserve the forest ecosystems and avoid the lost of valuable natural resources. Environmental stresses can affect tree biochemical and structural variables, such as the concentration, composition and efficiency in light harvesting of foliar pigments, and the Leaf Area Index (LAI. Interest in the use of these variables for forest condition assessment has recently increased because they can be indirectly estimated from remote observations at leaf and canopy level. In particular, in this research we found that total chlorophyll (Chl concentration, a biochemical variable related to crown discoloration rate, was the most suitable variable for the detection of pedunculate oak decline in the Ticino Park. A regression analysis between Chl concentration and optical indices computed from hyperspectral MIVIS data was performed in order to estimate Chl concentration from remote observations. The good correlation between field measurements of Chl concentration and MIVIS optical indices allowed the development of a model to map Chl concentration across the Ticino Park forested area. Promising results demonstrated that remotely sensed data can provide an accurate estimation of Chl concentration and indicated the potential of this technique for forest condition monitoring.

  13. Behavior of pubescent oak (Quercus pubescens Willd. wood to different thermal treatments

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    Todaro L

    2015-12-01

    Full Text Available Quercus pubescens Willd. is a common oak species in the Mediterranean area, where it is currently exploited mainly for purposes such as firewood. To improve the technological properties of its wood, various steaming and/or heat treatments were applied to 160 wood samples from a southern Italian stand, cut from either sapwood or heartwood, while 20 samples served as controls. Steaming was carried out in an autoclave at 120 °C, whereas heat treatments were performed in an oven at 150 or 200 °C for 3 or 6 h. The equilibrium moisture content, swelling, mass loss, wood density, compression strength, color variation, and lignin content of the samples were measured and compared among treatments. The swelling and water adsorption of wood samples decreased due to the hydrothermal treatments. The mass loss was strictly related to the temperature and duration of the heat treatments, whereas it was not influenced by the steaming treatment. The average axial compression strength value was positively influenced by the combination of steaming and heat treatments. A significant and general darkening of color was also observed for the harshest treatments, while an increase of lignin content was detected mainly in the sapwood. Thus, pubescent oak wood subjected to steaming and heat treatments may acquire useful characteristics suitable for its industrial use.

  14. The bulk elastic modulus and the reversible properties of cell walls in developing Quercus leaves.

    Science.gov (United States)

    Saito, Takami; Soga, Kouichi; Hoson, Takayuki; Terashima, Ichiro

    2006-06-01

    We examined the relationship between the bulk elastic modulus (epsilon) of an individual leaf obtained by the pressure-volume (P-V) technique and the mechanical properties of cell walls in the leaf. The plants used were Quercus glauca and Q. serrata, an evergreen and a deciduous broad-leaved tree species, respectively. We compared epsilon and Young's modulus of leaf specimens determined by the stretch technique at various stages of their leaf development. The results showed that epsilon increased from approximately 5 to 20 MPa during leaf development, although other potential determinants of epsilon such as the apoplastic water content in the leaf and the diameter of a palisade tissue cells remained almost constant. epsilon in these two species was similar at every developmental stages, although the apparent mechanical strength of the leaf lamina and thickness of mesophyll cell walls were greater in Q. glauca. There were significant linear relationships between Young's modulus and epsilon (P < 0.01; R (2) = 0.78 and 0.84 in Q. glauca and Q. serrata, respectively) with small y-intercepts. From these results, we conclude that epsilon is closely related to the reversible properties of the cell walls. From the estimation of epsilon based on a physical model, we suggest that the effective thickness of cell walls responsible for epsilon is smaller than the observed wall thickness.

  15. Genetic Differentiation between Quercus frainetto Ten. and Q. pubescens Willd. in Romania

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    Alexandru Lucian CURTU

    2011-05-01

    Full Text Available Little is known about genetic differences among Quercus frainetto and Q. pubescens, two species of section Dascia Kotschy (subgenus Lepidobalanus, white oaks that reach in Romania the margins of their natural distribution range. A set of genomic SSRs (simple sequence repeats and EST (expressed sequence tags-SSRs was used to estimate the genetic differentiation among four natural populations of the two species. Q. pubescens had higher values of genetic diversity than Q. frainetto, although the differences were not significant. Two out of seven marker-loci, QrZAG112 and QpZAG110, displayed very high FST values. Averaged across loci, the genetic differentiation was high and significant (FST = 0.067. Genetic distances were much higher among species than among populations within species. A Bayesian analysis indicated that two is the most appropriate number of genetic clusters. Using a blind procedure (i.e. based on multilocus genotypes only the vast majority of sampled individuals (90% could be assigned to the cluster corresponding to their phenotypes. When information about sampling localities was introduced in the assignment test, all individual trees were correctly classified. The higher degree of admixture in Q. frainetto as compared to Q. pubescens may be explained by different rates of introgressive hybridization.

  16. Imprints of natural selection along environmental gradients in phenology-related genes of Quercus petraea.

    Science.gov (United States)

    Alberto, Florian J; Derory, Jérémy; Boury, Christophe; Frigerio, Jean-Marc; Zimmermann, Niklaus E; Kremer, Antoine

    2013-10-01

    We explored single nucleotide polymorphism (SNP) variation in candidate genes for bud burst from Quercus petraea populations sampled along gradients of latitude and altitude in Western Europe. SNP diversity was monitored for 106 candidate genes, in 758 individuals from 32 natural populations. We investigated whether SNP variation reflected the clinal pattern of bud burst observed in common garden experiments. We used different methods to detect imprints of natural selection (FST outlier, clinal variation at allelic frequencies, association tests) and compared the results obtained for the two gradients. FST outlier SNPs were found in 15 genes, 5 of which were common to both gradients. The type of selection differed between the two gradients (directional or balancing) for 3 of these 5. Clinal variations were observed for six SNPs, and one cline was conserved across both gradients. Association tests between the phenotypic or breeding values of trees and SNP genotypes identified 14 significant associations, involving 12 genes. The results of outlier detection on the basis of population differentiation or clinal variation were not very consistent with the results of association tests. The discrepancies between these approaches may reflect the different hierarchical levels of selection considered (inter- and intrapopulation selection). Finally, we obtained evidence for convergent selection (similar for gradients) and clinal variation for a few genes, suggesting that comparisons between parallel gradients could be used to screen for major candidate genes responding to natural selection in trees.

  17. Biogeographic patterns of nutrient resorption from Quercus variabilis Blume leaves across China.

    Science.gov (United States)

    Sun, X; Kang, H; Chen, H Y H; Björn, B; Samuel, B F; Liu, C

    2016-05-01

    The variation in nutrient resorption has been studied at different taxonomic levels and geographic ranges. However, the variable traits of nutrient resorption at the individual species level across its distribution are poorly understood. We examined the variability and environmental controls of leaf nutrient resorption of Quercus variabilis, a widely distributed species of important ecological and economic value in China. The mean resorption efficiency was highest for phosphorus (P), followed by potassium (K), nitrogen (N), sulphur (S), magnesium (Mg) and carbon (C). Resorption efficiencies and proficiencies were strongly affected by climate and respective nutrients concentrations in soils and green leaves, but had little association with leaf mass per area. Climate factors, especially growing season length, were dominant drivers of nutrient resorption efficiencies, except for C, which was strongly related to green leaf C status. In contrast, green leaf nutritional status was the primary controlling factor of leaf nutrient proficiencies, except for C. Resorption efficiencies of N, P, K and S increased significantly with latitude, and were negatively related to growing season length and mean annual temperature. In turn, N, P, K and S in senesced leaves decreased with latitude, likely due to their efficient resorption response to variation in climate, but increased for Mg and did not change for C. Our results indicate that the nutrient resorption efficiency and proficiency of Q. variabilis differed strongly among nutrients, as well as growing environments. Our findings provide important insights into understanding the nutrient conservation strategy at the individual species level and its possible influence on nutrient cycling.

  18. Site quality assessment of degraded Quercus frainetto stands in central Greece

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    Kitikidou K

    2015-02-01

    Full Text Available The potential yield of a site is measured by site index, which is defined as the dominant height of a stand at a base age. A site index model for site quality assessment of Quercus frainetto (Hungarian oak stands in central Greece was developed using a base age of 50 years. Data were collected from 39 temporary sample plots of 10 x 10 m. Linear regression models widely used in site index studies were fitted to height-age data. The adjusted coefficient of determination (R2adj, root mean square error (RMSE, bias, coefficient of determination for the prediction (R2pr and residual plots were used for the choice of the best-fitting model. The best model was H = -0.231+0.251A-0.001A2, where H is the predicted height at age A. The guide curve method was adopted in constructing the sites curves, with the chosen model as the guide curve. Based on this curve, the study area was divided into three site quality classes (I to III, with class I representing the best and class III the poorest. Also, the presence of a Simpson’s paradox in these analyses is discussed. The results showed that a 50-year-old stand in the study area attained an average dominant height of about 11, 8 and 6 m on site quality classes I, II and III, respectively. The Hungarian oak stands of the present study can be considered very low productivity stands.

  19. Photosynthesis and photosynthetic electron flow in the alpine evergreen species Quercus guyavifolia in winter

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    Wei Huang

    2016-10-01

    Full Text Available Alpine evergreen broadleaf tree species must regularly cope with low night temperatures in winter. However, the effects of low night temperatures on photosynthesis in alpine evergreen broadleaf tree species are unclear. We measured the diurnal photosynthetic parameters before and after cold snap for leaves of Quercus guyavifolia growing in its native habitat at 3290 m. On 11 and 12 December 2013 (before cold snap, stomatal and mesophyll conductances (gs and gm, CO2 assimilation rate (An, and total electron flow through PSII (JPSII at daytime were maintained at high levels. The major action of alternative electron flow was to provide extra ATP for primary metabolisms. On 20 December 2013 (after cold snap, the diurnal values of gs, gm, An and JPSII at daytime largely decreased, mainly due to the large decrease in night air temperature. Meanwhile, the ratio of photorespiration and alternative electron flow to JPSII largely increased on 20 December. Furthermore, the high levels of alternative electron flow were accompanied with low rates of extra ATP production. A quantitative limitation analysis reveals that the gm limitation increased on 20 December with decreased night air temperature. Therefore, the night air temperature was an important determinant of stomatal/mesophyll conductance and photosynthesis. When photosynthesis is inhibited following freezing night temperatures, photorespiration and alternative electron flow are important electron sinks, which support the role of photorespiration and alternative electron flow in photoportection for alpine plants under low temperatures.

  20. Photosynthesis and Photosynthetic Electron Flow in the Alpine Evergreen Species Quercus guyavifolia in Winter

    Science.gov (United States)

    Huang, Wei; Hu, Hong; Zhang, Shi-Bao

    2016-01-01

    Alpine evergreen broadleaf tree species must regularly cope with low night temperatures in winter. However, the effects of low night temperatures on photosynthesis in alpine evergreen broadleaf tree species are unclear. We measured the diurnal photosynthetic parameters before and after cold snap for leaves of Quercus guyavifolia growing in its native habitat at 3290 m. On 11 and 12 December 2013 (before cold snap), stomatal and mesophyll conductances (gs and gm), CO2 assimilation rate (An), and total electron flow through PSII (JPSII) at daytime were maintained at high levels. The major action of alternative electron flow was to provide extra ATP for primary metabolisms. On 20 December 2013 (after cold snap), the diurnal values of gs, gm, An, and JPSII at daytime largely decreased, mainly due to the large decrease in night air temperature. Meanwhile, the ratio of photorespiration and alternative electron flow to JPSII largely increased on 20 December. Furthermore, the high levels of alternative electron flow were accompanied with low rates of extra ATP production. A quantitative limitation analysis reveals that the gm limitation increased on 20 December with decreased night air temperature. Therefore, the night air temperature was an important determinant of stomatal/mesophyll conductance and photosynthesis. When photosynthesis is inhibited following freezing night temperatures, photorespiration and alternative electron flow are important electron sinks, which support the role of photorespiration and alternative electron flow in photoportection for alpine plants under low temperatures. PMID:27812359

  1. Post-fire recolonization of dominant epiphytic lichen species on Quercus hypoleucoides (Fagaceae).

    Science.gov (United States)

    Romagni, J G; Gries, C

    2000-12-01

    Following a forest fire (27 500 ha) in 1994, post-fire recolonization of Quercus hypoeleucoides by epiphytic lichens was documented as changes in lichen cover, number of small thalli, specific factors that affected reestablishment of lichens, and modes of dispersal. Three sites in the Chiricahua Mountains (Arizona, USA) were chosen according to the severity of fire damage-unburned, moderately burned, and severely burned. From 1994 through 1997, the amount of dead lichen cover significantly increased at the moderately burned site. For the same time period, the amount of live lichen cover significantly increased at the severely burned site. Numbers of new thalli increased significantly at the severely burned site each year but only in the last year (1996-1997) for the moderately burned site. Bark texture and proximity to trees with lichens were among the most important physical factors for recolonization. The most important means of dispersal for Flavopunctelia praesignis was fragmentation. For Punctelia hypoleucites, the primary means of dispersal was spores. Increases in live lichen cover and numbers of new thalli occur faster in severely burned areas probably due to the loss of lichens on tree trunks, which provides space and a lack of competition.

  2. Estructura, dinámica y regeneración de los bosques mixtos de alcornoque (Quercus suber L.) y quejigo moruno (Q. canariensis Willd.) del sur de la Península Ibérica: una aproximación multiescala

    OpenAIRE

    I. R. Urbieta

    2009-01-01

    Resumen de Tesis Doctoral. Departamento de Ecología de la Universidad de Alcalá, e Instituto de Recursos Naturales y Agrobiología (IRNA), CSIC, Sevilla. Junio de 2008. Dirección: Miguel Ángel de Zavala y Teodoro Marañón. Financiado por los proyectos HETEROMED (REN2002-04041) y DINAMED (CGL2005–05830).

  3. The macrofungal diversity and community of Atlantic oak (Quercus petraea and Q. robur forests in Ireland

    Directory of Open Access Journals (Sweden)

    Harrington, Thomas J.

    2012-06-01

    Full Text Available The oak species Quercus petraea and Q. Robur are dominant canopy tree species of native deciduous forests in Ireland and coastal regions of Western Europe. These forests are typically plant species-rich, and can also have a rich fungal flora. This survey examined macrofungi found in five native oak sites across Ireland over three years. Overall, 94 macrofungal species belonging to 39 genera were discovered with Mycena, Lactarius, Russula and Cortinarius the most species-rich genera. The species accumulation curve did not show signs of levelling off, indicating that more sampling would reveal more new species. Species richness estimation using the Chao2 estimator indicated that up to 135 species may be present across all of our plots, with individual plots receiving estimates from 19 to 61 species per plot. Sampled-based rarefaction analysis showed no significant differences in macrofungal species richness between our plots. The five most common species were Laccaria amethystina, L. laccata, Stereum hirsutum, Armillaria mellea and Cortinarius flexipes. Comparisons of the results with results from oak forests in similar regions found that the communities in Great Britain were most similar to those found in Ireland. There were some key oak forest distinguishing fungal species from the family Boletaceae lacking from Irish oak forests. It is hypothesised that the historic deforestation of Ireland, caused a reduction of suitable habitats for Irish oak associated macrofungi, leading to the unspecific mycota found in the oak forests of this study. The threats to Atlantic oak forests in Ireland are briefly discussed.Las especies de Quercus petraea y Q. Robur se encuentran en bosques de Irlanda y regiones de influencia atlántica de Europa Occidental. Estos bosques, típicamente ricos en especies de plantas, presentan una abundante micobiota. Este estudio examina la diversidad de macromicetes en cinco bosques naturales de roble en Irlanda durante un

  4. The negative impact of intentionally introduced Quercus rubra L. on a forest community

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    Beata Woziwoda

    2014-03-01

    Full Text Available Some alien woody species used in commercial forestry become invasive and, as invaders, cause major problems in natural and semi-natural ecosystems. However, the deliberate introduction of aliens can bring unintended negative changes also within areas of their cultivation. This paper presents the effects of the intentional introduction of the North-American Quercus rubra in European mixed Scots pine-Pedunculate oak forests (POFs: Querco roboris-Pinetum (W. Mat. 1981 J. Mat. 1988. Phytosociological data from field research combined with GIS data analysis of the current distribution of Northern Red oak in the studied habitat were used to determine the composition and structure of forest communities in plots with and without Q. rubra participation.  The results show that Q. rubra significantly reduces native species richness and abundance, both in old-growth and in secondary (post-agricultural forests. Not one resident vascular plant benefits from the introduction of Northern Red oak and only a few are able to tolerate its co-occurrence. The natural restocking of all native woody species is also strongly limited by this alien tree.  The introduction of Northern Red oak significantly limits the environmental functions of the POF ecosystem and weakens its economic and social aspects. However, its further cultivation is justified from an economic point of view, as the essential function of the studied forests is commercial timber production, and the introduction of this fast growing alien tree supports the provisioning ecosystem services. A clear description of the level of trade-off between the accepted negative and positive effects of the introduction of Q. rubra on forest ecosystem services requires further interdisciplinary studies.

  5. Water metabolism of leaves of Quercus robur in antierosion stands in the south of its range

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    V. P. Bessonova

    2016-10-01

    Full Text Available We have investigated the main parameters of water exchange in leaves of Quercus robur L. which grow on the south-facing slope of the Viyskoviy ravine in a variety of water supply conditions. We established that the greatest intensity of transpiration of leaves of Q. robur occurred in the forest vegetation conditions of SG2, the smallest in SG1–0. In all study periods the largest amplitude of daily fluctuations in intensity of transpiration occurred in leaves of plants along the talweg, at other test sites the limits were much lower. The highest rates of transpiration were in September, which is connected with the high temperatures and lower relative air humidity compared with the days of measurement in July and May. We established that at the beginning of the growing season there was no difference in the total amount of water in the leaves of the trees that grow on the middle and upper parts of the slope, but that it was greater in plants along the talweg. In the following months the difference between the water content in the leaves of trees along the talweg and upper third of the slope increased. The leaves of trees that grow in the poorest conditions of water supply were characterized by the highest water-holding capacity, which is coordinated with their containing the highest content of hydrophilic colloids. The values for water deficit in May and in July fell within the maximum fluctuations for the species studied, but in early September they exceeded the maximum value in the leaves of trees on the upper third of the slope.

  6. Light response of hydraulic conductance in bur oak (Quercus macrocarpa) leaves.

    Science.gov (United States)

    Voicu, Mihaela C; Zwiazek, Janusz J; Tyree, Melvin T

    2008-07-01

    A four- to seven-fold enhancement of leaf hydraulic conductance by light has been reported in three temperate tree species. The enhancement occurs in the liquid-flow pathway between the petiole and the site of water evaporation. The enhancement occurs within 1 h, and dissipates in darkness over a period of 1 to 10 h depending on species. Here we report light-induced enhancement of leaf hydraulic conductance in a fourth species, bur oak (Quercus macrocarpa Michx.), the dependence of the effect on light flux and color, its absence in leaves of seedlings, and the impact on the response of leaf vein severance and several metabolic inhibitors. The light response of leaf hydraulic conductance approached saturation at a photosynthetic photon flux of 150 mumol m(-2) s(-1). Hydraulic enhancement was greater in response to blue and green light than to visible radiation of longer wavelengths, although at the same irradiance, the response to white light was greater than to light of any single color. Atrazine (a photosystem II inhibitor), fusicoccin (which stimulates plasma membrane-bound H(+)-ATPase) and HgCl(2) (an aquaporin blocker) reduced the light response of leaf lamina hydraulic conductance. When 2-mercaptoethanol was added following mercury treatment, the light response was totally suppressed. Our results are consistent with the notion that the effect of light on leaf lamina hydraulic conductance is controlled by factors acting outside the leaf veins, possibly through light-induced changes in membrane permeability of either mesophyll or bundle sheath cells, or both.

  7. Continuous Spectrum LEDs Promote Seedling Quality Traits and Performance of Quercus ithaburensis var. macrolepis.

    Science.gov (United States)

    Smirnakou, Sonia; Ouzounis, Theoharis; Radoglou, Kalliopi M

    2017-01-01

    Regulation of the growth, development, and quality of plants by the control of light quality has attracted extensive attention worldwide. The aim of this study was to examine the effects of continuous LED spectrum for indoor plant pre-cultivation and to investigate the morphological and physiological responses of a common broadleaved tree species in Mediterranean environment, Quercus ithaburensis var. macrolepis at seedling developmental stage. Thus, the seedlings were pre-cultivated for 28 days, under five different LED light qualities: (1) Fluorescent (FL) as control light (2) L20AP67 (high in green and moderate in far-red), (3) AP673L (high in green and red), (4) G2 (highest in red and far-red), AP67 (high in blue, red, and far-red), and (5) NS1 (highest in blue and green and lowest in far-red) LEDs. Further examination was held at the nursery for 1 year, on several seedling quality traits. Indeed, AP67 and AP673L triggered higher leaf formation, while L20AP67 positively affected seedling shoot development. NS1 and AP67 LED pre-cultivated seedlings showed significantly higher root fibrosity than those of FL light. Furthermore, NS1 and AP673L LEDs induced fourfold increase on seedling root dry weight than FL light. Hence, evaluating the seedling nursery performance attributes, most of those photomorphogenetic responses previously obtained were still detectable. Even more so, LED pre-cultivated seedlings showed higher survival and faster growth indicating better adaptation even under natural light conditions, a fact further reinforced by the significantly higher Dickson's quality index acquired. In conclusion, the goal of each nursery management program is the production of high quality seedlings with those desirable traits, which in turn satisfy the specific needs for a particular reforestation site. Thus, the enhanced oak seedling quality traits formed under continuous LEDs spectrum especially of NS1 and AP673L pre-cultivation may potentially fulfill this goal.

  8. Addressing post-transplant summer water stress in Pinus pinea and Quercus ilex seedlings

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    Pardos M

    2015-06-01

    Full Text Available In central Spain, post-transplant water stress produces high seedling mortality after the first summer following outplanting. Our study was designed to determine whether survival and performance of outplanted stone pine (Pinus pinea and holm oak (Quercus ilex seedlings in a burned area could be improved by summer irrigation and mulching and to identify whether there is a species-specific adaptive capacity to respond to treatment and environment. Seedlings were outplanted in March 2011 in 200 planting holes in an area of 1.1 ha. Mulch was added in June; irrigation started in July and was repeated every week until mid-September. The severity of the 2011 summer drought constrained growth rates and photosynthetic characteristics, mainly in the non-irrigated seedlings, whose survival at the end of the year after planting was approximately 2.5%. Stone pine and holm oak seedlings responded more to irrigation than to mulching in terms of shoot growth, biomass and survival. Furthermore, stone pine seedlings were found to be more responsive to the partial alleviation of summer drought than holm oak seedlings. Irrigation alone produced similar results to those obtained when both irrigation and mulching were employed. In conclusion, first year summer irrigation should be considered as a planned adaptation measure in the management of outplanted Mediterranean ecosystems, because once a gravimetrically measured soil moisture level as low as 2% is achieved seedling survival and physiological performance can be guaranteed. However, the repercussions for the potential persistence of both species in the area will not only be related to the recurrence and intensity of summer droughts but also to drought duration.

  9. ECUACIONES ALOMÉTRICAS PARA ESTIMAR BIOMASA Y CARBONO EN Quercus magnoliaefolia

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    Jesús D. Gómez-Díaz

    2011-01-01

    Full Text Available En el ejido El Zapote de la Reserva de la Biosfera "Sierra de Huautla", estado de Morelos, México, se seleccionaron doce árboles de Quercus magnoliaefolia Née y se determinó su biomasa en la parte aérea. El modelo alométrico quedó expresado como: B = 0.0345 * DAP2.9334 en donde B es la biomasa (kg y DAP es el diámetro a la altura del pecho (cm, con un coeficiente de determinación (R2= 0.98; P<0.001. Adicionalmente, se estimó la biomasa mediante una regresión lineal múltiple que consideró el área basal (AB, la densidad específica de la madera (DEM y la altura de los árboles (H. Una alta proporción de la varianza de la biomasa fue explicada solamente por el área basal. La DEM y H no incrementaron significativamente la precisión de los modelos. El porcentaje promedio de carbono en los árboles de Q. magnoliaefolia fue de 47.14 con valores de 46.29 % para el fuste, 46.83 % para las ramas y 48.31 % para el follaje. La proporción promedio de los componentes de la especie estudiada fue de 2.5 % para el fuste, 27.8 % para las ramas y 9.6 % para el follaje.

  10. Indirect effects of precipitation variation on the decomposition process of Mongolian oak (Quercus mongolica) leaf litter

    Institute of Scientific and Technical Information of China (English)

    LI Xuefeng; HAN Shijie; ZHANG Yan

    2007-01-01

    The effect of precipitation variation on the chemistry of Mongolian oak(Quercus mongolica)leaf litters was examined by analyzing litters of Mongolia oak saplings under four precipitation gradients.The decomposing process of these leaf litters in the Mongolian oak dominated forest was assessed using litter bag method.Compared with the litters of the Mongolian oak saplings from the natural precipitation site(A),litters produced by Mongolian oak from the driest precipitation gradient(A450)had significantly higher concentrations of nitrogen(N),phosphorus(P)and potassium(K)while lower acid-insoluble fraction(A/F)concentration.The decomposition study showed that A450 exhibited significantly higher decomposition rate,mineralization rates of N,P and K as well as much shorter N and P net immobilization periods.On the contrary,litters produced by seedlings from wettest gradient(Ass0)showed a totally opposite pattern.Litters from saplings that received comparable precipitation(A650)to those at the natural site(A)had significantly higher N concentration and faster decomposition rate as well as release rates of N,P and K.The mass loss patterns for the four litter types fitted the exponential model and the decay constant(k)can be well predicted by initial AIF/N.During the decomposition period,N concentration was best related to the percentage of mass remaining of the litters with relatively higher AIF concentrations and lower N concentrations,but the percentage of mass remaining of litters with lower AIF concentrations and higher N concentrations correlates strongly with AIF concentration.Our study proved that changes in precipitation significantly altered the litter quality,and therefore indirectly changed the decay process of leaf litters.

  11. Physiological function of insoluble dietary fiber prepared from exploded oak wood (Quercus mongolica).

    Science.gov (United States)

    Yang, Jae-Kyung; Choi, Myung-Suk; Kim, Chang-Joon; Shin, Yong-Seung; Han, Dae-Yong; Han, Sang-Woo; Lim, Bu-Kug; Lee, Jong-Yoon; Rhee, Soon-Jae; Kim, Eun-Hee; Kim, Gon-Sup

    2006-01-01

    This study investigated the production of insoluble dietary fiber using exploded and chemically treated oak wood (Quercus mongolica) and the physiological functions of prepared insoluble dietary fiber in laboratory animals. To produce high quality insoluble dietary fiber, the steam explosion treatment was performed at 25 kgf/cm2 pressure for 6 minutes. In the chemical analysis of insoluble dietary fiber, exploded oak wood was pretreated by 1% sodium hydroxide solution. The insoluble dietary fiber contained 7.6% residual lignin and 61.7% of alpha-cellulose. In order to compare the physiological functions of prepared insoluble dietary fiber with those of commercial insoluble dietary fiber, Sprague-Dawley male rats weighing 100 +/- 10 g were randomly assigned to one normal diet and five high cholesterol diets, containing 1% cholesterol. The high cholesterol diet groups were classified as the fiber-free diet (FF group), 5% commercial alpha-cellulose diet group (5C group), 10% commercial alpha-cellulose group (10C group), 5% insoluble dietary fiber group (5M group) and 10% insoluble dietary fiber group (10M group). Food intake, weight gain and food efficiency ratio in high cholesterol groups were significantly higher than those of the normal group, but there were no significant differences among the high cholesterol diet groups. In addition, there were no significant differences in the weights of liver, kidney and small intestine in insoluble dietary fiber-supplemented groups. Cecum weights in all insoluble dietary fiber groups were significantly higher than those of the FF group. There were no significant differences in the activities of the glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) among the insoluble dietary fiber-supplemented groups. In conclusion, the prepared insoluble dietary fiber and the commercially available insoluble fiber showed the same physiological effects. Moreover, the preparation method for the insoluble dietary

  12. Soil Respiration in Relation to Photosynthesis of Quercus mongolica Trees at Elevated CO2

    Science.gov (United States)

    Zhou, Yumei; Li, Mai-He; Cheng, Xu-Bing; Wang, Cun-Guo; Fan, A-Nan; Shi, Lian-Xuan; Wang, Xiu-Xiu; Han, Shijie

    2010-01-01

    Knowledge of soil respiration and photosynthesis under elevated CO2 is crucial for exactly understanding and predicting the carbon balance in forest ecosystems in a rapid CO2-enriched world. Quercus mongolica Fischer ex Ledebour seedlings were planted in open-top chambers exposed to elevated CO2 (EC = 500 µmol mol−1) and ambient CO2 (AC = 370 µmol mol−1) from 2005 to 2008. Daily, seasonal and inter-annual variations in soil respiration and photosynthetic assimilation were measured during 2007 and 2008 growing seasons. EC significantly stimulated the daytime soil respiration by 24.5% (322.4 at EC vs. 259.0 mg CO2 m−2 hr−1 at AC) in 2007 and 21.0% (281.2 at EC vs. 232.6 mg CO2 m−2 hr−1 at AC) in 2008, and increased the daytime CO2 assimilation by 28.8% (624.1 at EC vs. 484.6 mg CO2 m−2 hr−1 at AC) across the two growing seasons. The temporal variation in soil respiration was positively correlated with the aboveground photosynthesis, soil temperature, and soil water content at both EC and AC. EC did not affect the temperature sensitivity of soil respiration. The increased daytime soil respiration at EC resulted mainly from the increased aboveground photosynthesis. The present study indicates that increases in CO2 fixation of plants in a CO2-rich world will rapidly return to the atmosphere by increased soil respiration. PMID:21151897

  13. [Effects of light intensity on Quercus liaotungensis seed germination and seedling growth].

    Science.gov (United States)

    Yan, Xing-fu; Wang, Jian-li; Zhou, Li-biao

    2011-07-01

    This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability.

  14. How drought severity constrains GPP and its partitioning among carbon pools in a Quercus ilex coppice?

    Directory of Open Access Journals (Sweden)

    S. Rambal

    2014-06-01

    Full Text Available The partitioning of photosynthates toward biomass compartments has a crucial role in the carbon sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought prone forests. We analyzed the fate of GPP in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Gross and net carbon fluxes between the ecosystem and the atmosphere were measured with an eddy-covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy-covariance fluxes with annual productions we managed to close a C budget and derive values of autotrophic and heterotrophic respirations, NPP and carbon use efficiency (CUE, the ratio between NPP and GPP. Average values of yearly NEP, GPP and Reco were 282, 1259 and 977 g C m−2. The corresponding ANPP components were 142.5, 26.4 and 69.6 g C m−2 for leaves, reproductive effort (flowers and fruits and stems. Gross and net carbon exchange between the ecosystem and the atmosphere were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected, the stem growth, to the least affected, the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease more slightly in response to drought than GPP and NPP, probably due to drought-acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem and highlight the value of maintaining continuous

  15. Antioxidant and α-glucosidase inhibitor activities of natural compounds isolated from Quercus gilva Blume leaves

    Institute of Scientific and Technical Information of China (English)

    Anastasia Wheni Indrianingsih; Sanro Tachibana; Rizna Triana Dewi; Kazutaka Itoh

    2015-01-01

    To isolate and investigate antioxidant and α-glucosidase inhibitor compounds in the leaves of Quercus gilva Blume (Q. gilva). Methods: Dry leaves of Q. gilva were extracted with methanol and the methanolic extract was further separated by silica gel column chromatography using several solvents with increasing polarity. The antioxidant activities of the isolated compounds were evaluated using various in vitro assays: 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydrogen peroxide radical scavenging activity, β-carotene bleaching assay, and reducing power assay. The α-glucosidase inhibitory assay was conducted against α-glucosidase from Saccharomyces cerevisiae. Results: Three compounds were isolated and their structures were identified as catechin (1), epicatechin (2), and tiliroside (3) using an instrumental analysis. Compound 2 had higher antioxidant activity with inhibitory concentrations (IC50) of (22.55 ± 2.23) µmol/L than that of quercetin, which was used as the standard, with an IC50 of (28.08 ± 2.39) µmol/L, followed by compound 1 with IC50 of (40.86 ± 3.45) µmol/L. On the other hand, compound 3 had the lowest antioxidant activity with an IC50 of (160.24 ± 8.15) µmol/L. However, compound 3 had the highest α-glucosidase inhibitory activity with an IC50 of (28.36 ± 0.11) µmol/L, followed by compounds 1 and 2 with (168.60 ± 5.15) and (920.60 ± 10.10) µmol/L, respectively. Conclusions: The results obtained for the antioxidant activities and α-glucosidase inhibitory activities in a methanolic extract from the leaves of Q. gilva confirmed the potential of this plant as a source of natural antioxidants and antidiabetic medicine.

  16. Antioxidant and α-glucosidase inhibitor activities of natural compounds isolated from Quercus gilva Blume leaves

    Institute of Scientific and Technical Information of China (English)

    Anastasia; Wheni; Indrianingsih; Sanro; Tachibana; Rizna; Triana; Dewi; Kazutaka; Itoh

    2015-01-01

    Objective: To isolate and investigate antioxidant and α-glucosidase inhibitor compounds in the leaves of Quercus gilva Blume(Q. gilva).Methods: Dry leaves of Q. gilva were extracted with methanol and the methanolic extract was further separated by silica gel column chromatography using several solvents with increasing polarity. The antioxidant activities of the isolated compounds were evaluated using various in vitro assays: 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydrogen peroxide radical scavenging activity, β-carotene bleaching assay, and reducing power assay. The α-glucosidase inhibitory assay was conducted against α-glucosidase from Saccharomyces cerevisiae.Results: Three compounds were isolated and their structures were identii ed as catechin(1), epicatechin(2), and tiliroside(3) using an instrumental analysis. Compound 2 had higher antioxidant activity with inhibitory concentrations(IC50) of(22.55 ± 2.23) μmol/L than that of quercetin, which was used as the standard, with an IC50 of(28.08 ± 2.39) μmol/L, followed by compound 1 with IC50 of(40.86 ± 3.45) μmol/L. On the other hand, compound 3 had the lowest antioxidant activity with an IC50 of(160.24 ± 8.15) μmol/L. However, compound 3 had the highest α-glucosidase inhibitory activity with an IC50 of(28.36 ± 0.11) μmol/L, followed by compounds 1 and 2 with(168.60 ± 5.15) and(920.60 ± 10.10) μmol/L, respectively.Conclusions: The results obtained for the antioxidant activities and α-glucosidase inhibitory activities in a methanolic extract from the leaves of Q. gilva coni rmed the potential of this plant as a source of natural antioxidants and antidiabetic medicine.

  17. Is thinning adequate for adapting old Quercus ilex coppices to climate change?

    Science.gov (United States)

    Rodriguez-Calcerrada, Jesus; Perez-Ramos, Ignacio-Manuel; Ourcival, Jean-Marc; Limousin, Jean-Marc; Misson, Laurent; Joffre, Richard; Rambal, Serge; Martin, Nicolas

    2010-05-01

    Future climatic scenarios call for an increasing involvement of management for forest preservation, but little is known on how forestry practices will benefit stands in facing variation of climatic components. We investigated how thinning affected tree responses to six years of continued throughfall reduction in a Mediterranean Quercus ilex stand formerly managed as a coppice. Thinned plots (≈33% basal area removal) and unthinned plots were subsequently subject to either throughfall exclusion (≈28% throughfall reduction) or normal rainfall. Stem-diameter growth, stem survival and seed production were monitored over the following six years; the presence, abundance and growth of new sprouts were measured in the last year. In the absence of thinning, throughfall exclusion accelerated the mortality of small stems, reduced the production of viable acorns and stimulated the emergence of new sprouts. Throughfall exclusion did not have any effect on stem growth. Rather, trees responded to the imposed reduction on throughfall by decreasing the leaf area and thus by minimizing the risk of xylem cavitation. Thinning reduced the mortality of stems, enhanced the diameter growth of residual stems and caused a profuse emission of resprouts. Thinning also increased total seed production but the crop had a large proportion of aborted seeds. Overall, the results point out to a better disposition of thinned Q. ilex coppice stands to cope with future (probably longer and more intense) droughts, at least in the short term. The reduction in standing dead biomass reduces the probability of occurrence of wildfires while the increase in growth and probably carbon reserves may help trees to overcome dry summers where CO2 assimilation is strongly limited. The mere felling of dominated and diseased stems, however, will probably not result in any longer-term advantage derived from seed regeneration without any further silvicultural treatment that promote seedling recruitment.

  18. How drought severity constrains GPP and its partitioning among carbon pools in a Quercus ilex coppice?

    Science.gov (United States)

    Rambal, S.; Lempereur, M.; Limousin, J. M.; Martin-StPaul, N. K.; Ourcival, J. M.; Rodríguez-Calcerrada, J.

    2014-06-01

    The partitioning of photosynthates toward biomass compartments has a crucial role in the carbon sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought prone forests. We analyzed the fate of GPP in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Gross and net carbon fluxes between the ecosystem and the atmosphere were measured with an eddy-covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy-covariance fluxes with annual productions we managed to close a C budget and derive values of autotrophic and heterotrophic respirations, NPP and carbon use efficiency (CUE, the ratio between NPP and GPP). Average values of yearly NEP, GPP and Reco were 282, 1259 and 977 g C m-2. The corresponding ANPP components were 142.5, 26.4 and 69.6 g C m-2 for leaves, reproductive effort (flowers and fruits) and stems. Gross and net carbon exchange between the ecosystem and the atmosphere were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected, the stem growth, to the least affected, the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease more slightly in response to drought than GPP and NPP, probably due to drought-acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem and highlight the value of maintaining continuous experimental

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

    Science.gov (United States)

    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.

  20. BVOC emissions from English oak (Quercus robur) and European beech (Fagus sylvatica) along a latitudinal gradient

    Science.gov (United States)

    van Meeningen, Ylva; Schurgers, Guy; Rinnan, Riikka; Holst, Thomas

    2016-11-01

    English oak (Quercus robur) and European beech (Fagus sylvatica) are amongst the most common tree species growing in Europe, influencing the annual biogenic volatile organic compound (BVOC) budget in this region. Studies have shown great variability in the emissions from these tree species, originating from both genetic variability and differences in climatic conditions between study sites. In this study, we examine the emission patterns for English oak and European beech in genetically identical individuals and the potential variation within and between sites. Leaf scale BVOC emissions, net assimilation rates and stomatal conductance were measured at the International Phenological Garden sites of Ljubljana (Slovenia), Grafrath (Germany) and Taastrup (Denmark). Sampling was conducted during three campaigns between May and July 2014. Our results show that English oak mainly emitted isoprene whilst European beech released monoterpenes. The relative contribution of the most emitted compounds from the two species remained stable across latitudes. The contribution of isoprene for English oak from Grafrath and Taastrup ranged between 92 and 97 % of the total BVOC emissions, whilst sabinene and limonene for European beech ranged from 30.5 to 40.5 and 9 to 15 % respectively for all three sites. The relative contribution of isoprene for English oak at Ljubljana was lower (78 %) in comparison to the other sites, most likely caused by frost damage in early spring. The variability in total leaf-level emission rates from the same site was small, whereas there were greater differences between sites. These differences were probably caused by short-term weather events and plant stress. A difference in age did not seem to affect the emission patterns for the selected trees. This study highlights the significance of within-genotypic variation of BVOC emission capacities for English oak and European beech, the influence of climatic variables such as temperature and light on emission

  1. Associations between growth, wood anatomy, carbon isotope discrimination and mortality in a Quercus robur forest.

    Science.gov (United States)

    Levanic, Tom; Cater, Matjaz; McDowell, Nate G

    2011-03-01

    Observations of forest mortality are increasing globally, but relatively little is known regarding the underlying mechanisms driving these events. Tree rings carry physiological signatures that may be used as a tool for retrospective analyses. We capitalized on a local soil water drainage event in 1982 that resulted in increased mortality within a stand of oak trees (Quercus robur), to examine the underlying physiological patterns associated with survival and death in response to soil water limitations. Pre-dawn water potentials showed more negative values for trees in the process of dying compared with those that survived. We used tree rings formed over the 123 years prior to mortality to estimate productivity from basal area increment (BAI, mm(2)), multiple xylem hydraulic parameters via anatomical measurements and crown-level gas exchange via carbon isotope discrimination (Δ, ‰). Oaks that died had significantly higher BAI values than trees that survived until the drainage event, after which the BAI of trees that died declined dramatically. Hydraulic diameter and conductivity of vessels in trees that died were higher than in surviving trees until the last 5 years prior to mortality, at which time both groups had similar values. Trees that died had consistently lower Δ values than trees that survived. Therefore, tree mortality in this stand was associated with physiological differences prior to the onset of soil water reduction. We propose that trees that died may have been hydraulically underbuilt for dry conditions, which predisposes them to severe hydraulic constraints and subsequent mortality. Measurements of above-ground/below-ground dry mass partitioning will be critical to future tests of this hypothesis. Based on these results, it is probable that pedunculate oak trees will experience greater future mortality if climate changes cause more severe droughts than the trees have experienced previously.

  2. [Effects of simulated acid rain on Quercus glauca seedlings photosynthesis and chlorophyll fluorescence].

    Science.gov (United States)

    Li, Jia; Jiang, Hong; Yu, Shu-quan; Jiang, Fu-wei; Yin, Xiu-min; Lu, Mei-juan

    2009-09-01

    Taking the seedlings of Quercus glauca, a dominant evergreen broadleaf tree species in subtropical area, as test materials, this paper studied their photosynthesis, chlorophyll fluorescence, and chlorophyll content under effects of simulated acid rain with pH 2.5, 4.0, and 5.6 (CK). After 2-year acid rain stress, the net photosynthetic rate of Q. glauca increased significantly with decreasing pH of acid rain. The acid rain with pH 2.5 and 4.0 increased the stomatal conductance and transpiration rate, and the effect was more significant under pH 2.5. The intercellular CO2 concentration decreased in the order of pH 2.5 > pH 5.6 > pH 4.0. The maximum photosynthetic rate, light compensation point, light saturation point, and dark respiration rate were significantly higher under pH 2.5 and 4.0 than under pH 5.6, while the apparent quantum yield was not sensitive to acid rain stress. The maximal photochemical efficiency of PS II and the potential activity of PS II under pH 2.5 and 4.0 were significantly higher than those under pH 5.6. The relative chlorophyll content was in the order of pH 2.5 > pH 5.6 > pH 4.0, and there was a significant difference between pH 2.5 and 4.0. All the results suggested that the photosynthesis and chlorophyll fluorescence of Q. glauca increased under the effects of acid rain with pH 2.5 and 4.0, and the acid rain with pH 2.5 had more obvious effects.

  3. Ecophysiological characteristics and cadmium accumulation in Downy Oak (Quercus pubescens Willd.

    Directory of Open Access Journals (Sweden)

    Cocozza C

    2012-10-01

    Full Text Available Heavy metals provoke environmental pollution with potentially toxic effects on human and plants systems. Recently, investigations are conducted on plants that may play a relevant role on pollutants absorption or stabilization, focusing on fast growing tree species in agronomic conditions; little is known on the effects of contaminants on tree species colonizing abandoned fields to be used in restoration ecology. The effects of Cd on photosynthetic performance and metal accumulation were investigated in Quercus pubescens Willd. seedlings grown in pots containing a mixture of sand, clay, turf and Cd-treatments (0, 25 and 75 mg kg-1 dry soil. The studied photosynthetic parameters (Asat= net phytosynthesis; Rday= day respiration; Γcomp= CO2 compensation point; Vcmax= maximum carboxylation rate; Jmax = electron transport rate; TPU = triose phosphate use; Ci/Ca = ratio of intercellular (Ci to ambient (Ca [CO2] (Ci/Ca; Jmax/Vcmax = ratio; (gsmax = maximum stomatal conductance; (lg = stomatal conductance estimated relative to the photosynthetic rate; (Fv/Fm = maximum quantum yield of PSII photochemistry; (ΔF/F’m = effective photochemical efficiency varied progressively with increasing Cd concentration in the soil, highlighting a negative impact on photosynthetic potential and PSII functioning. Approximately 10% of added Cd was found to be extractable from the substrate, at the maximum concentration applied, with about 12 and 0.75 as bioaccumulation and translocation factors, respectively. Analogously, Cd accumulated up to 34, 30 and 46 mg kg−1 in leaves, stem and roots, respectively. While it is not possible to extrapolate from the present study with seedlings to effects on mature pine trees, there are clear implications for regeneration in soils contaminated with heavy metals, which may lead to ecosystem deterioration.

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

    Science.gov (United States)

    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.

  5. Influence of pericarp, cotyledon and inhibitory substances on sharp tooth oak (Quercus aliena var. acuteserrata germination.

    Directory of Open Access Journals (Sweden)

    Yan Liu

    Full Text Available In order to explore the mechanism of delayed and uneven germination in sharp tooth oak (Quercus aliena var. acuteserrata (STO, mechanical scarification techniques were used to study STO root and shoot germination and growth. The techniques used were: removing cup scar (RS, removing the pericarp (RP, and cutting off 1/2 (HC and 2/3 (TC cotyledons. Germination percentage and root and shoot length for Chinese cabbage (Beassica pekinensis seeds (CCS were also investigated for CCS cultivated in a Sanyo growth cabinet watered by distilled water and 80% methanol extracts from the acorn embryo, cotyledon and pericarp with concentrations of 1.0 g, 0.8 g, 0.6 g and 0.4 g dry acorn weight per ml methanol. The results showed that the majority of roots and shoots from acorns with RP and HC treatment emerged two weeks earlier, more simultaneously, and their total emergencies were more than 46% and 28% higher, respectively. TC accelerated root and shoot emergence time and root length, but root and shoot germination rate and shoot height had no significant difference from the control. Positive consequences were not observed on all indices of RS treatment. The germination rates of CCS watered by 1.0 g · ml(-1 methanol extracts from the embryo and cotyledon were significantly lower than those from the pericarp, and all concentrations resulted in decreased growth of root and shoot. Methanol extracts from pericarp significantly reduced root length of CCS, but presented little response in germination percentage and shoot length. The inhibitory effect was gradually increased with the increasing concentration of the methanol extract. We conclude that both the mechanical restriction of the pericarp and the presence of germination inhibitors in the embryo, cotyledon and pericarp are the causes for delayed and asynchronous germination of STO acorns.

  6. Reference Gene Selection in the Desert Plant <em>Eremosparton songoricuem>m>

    Directory of Open Access Journals (Sweden)

    Dao-Yuan Zhang

    2012-06-01

    Full Text Available <em>Eremosparton songoricum em>(Litv. Vass. (<em>E. songoricumem> is a rare and extremely drought-tolerant desert plant that holds promise as a model organism for the identification of genes associated with water deficit stress. Here, we cloned and evaluated the expression of eight candidate reference genes using quantitative real-time reverse transcriptase polymerase chain reactions. The expression of these candidate reference genes was analyzed in a diverse set of 20 samples including various <em>E. songoricumem> plant tissues exposed to multiple environmental stresses. GeNorm analysis indicated that expression stability varied between the reference genes in the different experimental conditions, but the two most stable reference genes were sufficient for normalization in most conditions.<em> EsEFem> and <em>Esα-TUB> were sufficient for various stress conditions, <em>EsEF> and <em>EsACT> were suitable for samples of differing germination stages, and <em>EsGAPDH>and <em>Es>UBQ em>were most stable across multiple adult tissue samples. The <em>Es18Sem> gene was unsuitable as a reference gene in our analysis. In addition, the expression level of the drought-stress related transcription factor <em>EsDREB2em>> em>verified the utility of<em> E. songoricumem> reference genes and indicated that no single gene was adequate for normalization on its own. This is the first systematic report on the selection of reference genes in <em>E. songoricumem>, and these data will facilitate future work on gene expression in this species.

  7. Three new species of Collembola from soils of Mediterranean cork-oak forests of Sicily (Italy).

    Science.gov (United States)

    Giuga, Luca; Jordana, Rafael

    2013-01-01

    Three new species of soil Collembola from cork-oak (Quercus suber) forests located in eastern Sicily (Italy) are described Neonaphorura alicatai sp. nov., Friesea guarinoi sp. nov. and Arrhopalites antonioi sp. nov..

  8. Independencia y ecología ectomicorrícica en varias especies de los géneros Quercus, Pinus y Eucalyptus

    OpenAIRE

    Oria de Rueda Salguero, Juan Andrés

    1991-01-01

    Se estudia la micorrización de varias especies de Quercus y Eucalyptus con hongos micorrícicos de los géneros Pisolithus, Krombholziella y Suillus. Se define el Período de Independencia Micorrícica, muy interesante en viveros forestales y de reproducción vegetal.Este período varía según especies y ecología y es mayor con semillas voluminosas que en las de semillas pequeñas. Mycorrization of some species of Quercus, Pinus and Eucalyptus with some mycorrhizal fungi: Pisolithus,Krombholziella...

  9. Ecología, historia y gestión de los árboles del género Quercus: simposio de Isparta, Turquía

    OpenAIRE

    Marañón, T.

    2011-01-01

    El género Quercus tiene más de 400 especies repartidas por el Hemisferio Norte. Los robles, encinas, alcornoques, quejigos y coscojas forman parte del paisaje europeo y mediterráneo y tienen un importante valor ecológico, económico y cultural. En junio de 2010 tuvo lugar en Isparta (Turquía) el segundo simposio europeo sobre la importancia de los árboles del género Quercus, 'su contribución pasada, presente y futura al paisaje, la biodiversidad, el patrimonio y el turismo europeo' (v...

  10. Synthesis, Crystal Structure and Luminescent Property of Cd (II Complex with <em>N-Benzenesulphonyl-L>-leucine

    Directory of Open Access Journals (Sweden)

    Xishi Tai

    2012-09-01

    Full Text Available A new trinuclear Cd (II complex [Cd3(L6(2,2-bipyridine3] [L =<em> Nem>-phenylsulfonyl-L>-leucinato] has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The results show that the complex belongs to the orthorhombic, space group<em> Pem>212121 with<em> aem> = 16.877(3 Å, <em>b> em>= 22.875(5 Å, <em>c em>= 29.495(6 Å, <em>α> em>= <emem>= <emem>= 90°, <em>V> em>= 11387(4 Å3, <em>Z> em>= 4, <em>Dc>= 1.416 μg·m−3, <emem>= 0.737 mm−1, <em>F> em>(000 = 4992, and final <em>R>1 = 0.0390, <em>ωR>2 = 0.0989. The complex comprises two seven-coordinated Cd (II atoms, with a N2O5 distorted pengonal bipyramidal coordination environment and a six-coordinated Cd (II atom, with a N2O4 distorted octahedral coordination environment. The molecules form one dimensional chain structure by the interaction of bridged carboxylato groups, hydrogen bonds and p-p interaction of 2,2-bipyridine. The luminescent properties of the Cd (II complex and <em>N-Benzenesulphonyl-L>-leucine in solid and in CH3OH solution also have been investigated.

  11. Conservation and fruit biology of Sichou oak (Quercus sichourensis, Fagaceae – A critically endangered species in China

    Directory of Open Access Journals (Sweden)

    Ke Xia

    2016-10-01

    Full Text Available Several conservation programs have been started for the critically endangered Sichou oak (Quercus sichourensis since 2007. These programs include detailed field investigations, seedling cultivation and research on the fruit biology of the species. In this study, we first report on the five mature individual trees found in our 9-year field investigation. Thus far, a total of 10 mature individuals have been recorded. All Q. sichourensis trees are healthy and most produce healthy acorns. Acorns of Q. sichourensis are large with dry masses of 8.0–14.0 g. These acorns had high moisture contents at collection and died shortly after (7–28 d when dried with silica gel. Characteristics of Q. sichourensis acorns varied between populations. Compared with the acorns from Funing, the acorns collected from Ceheng were bigger, more viable (germination percentage was up to 96%, less sensitive to desiccation, and germinated faster. Q. sichourensis occurs in regions with a distinct 5–6 month dry season. Habitat degradation is largely responsible for the rareness of Quercus sichorensis, but desiccation sensitivity of the acorns may also limit the regeneration of the species and potentially lead to its continued rareness. As a species with extremely small populations (PSESP, Q. sichourensis is facing high risk of extinction and should be defined as a Critically Endangered species in the global IUCN Red List.

  12. Tree-ring growth and wood chemistry response to manipulated precipitation variation for two temperate Quercus species

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Rebekah J. [Pennsylvania State University, University Park, PA; Kaye, Margot W. [Pennsylvania State University, University Park, PA; Abrams, Marc D. [Pennsylvania State University, University Park, PA; Hanson, Paul J [ORNL; Martin, Madhavi Z [ORNL

    2012-01-01

    We examined the relationship among ambient and manipulated precipitation, wood chemistry, and their relationship with radial growth for two oak species in eastern Tennessee. The study took place on the Walker Branch Throughfall Displacement Experiment (TDE) site, located at the Oak Ridge National Laboratory in Oak Ridge, TN. Two dominant species, white oak (Quercus alba) and chestnut oak (Quercus prinus), were selected for study from a 13-year experiment of whole-stand precipitation manipulation (wet, ambient and dry). The relationships between tree-ring width and climate were compared for both species to determine the impact of precipitation manipulations on ring width index. This study used experimental spectroscopy techniques to measure the sensitivity of tree-ring responses to directional changes in precipitation over 13 years, and the results suggest that oaks at this study site are resilient to imposed changes, but sensitive to inter-annual variations in climate. Laser-induced breakdown spectroscopy (LIBS) allowed us to measure nutrient intensities (similar to element concentrations) at 0.5-1.0 mm spacing along the radial growth axis of trees growing in the wet, ambient, and dry treatment sites. A difference in stemwood nutrient levels was observed between the two oak species and among the three treatments. Significant variation in element intensity was observed across treatments for some elements (Ca, K, Mg, Na, N and P) suggesting the potential for long-term impacts on growth under a changing climate regimes for southeastern oaks.

  13. [Effects of relative abundance of Quercus mongolica acorns on five tree species seed dispersal in Xiaoxing' an Mountains, Northeast China].

    Science.gov (United States)

    Yu, Fei; Shi, Xiao-Xiao; Yi, Xian-Feng; Wang, De-Xiang

    2013-06-01

    An investigation was conducted in a forest farm in the Xiaoxing' an Mountains in autumn, 2009 and 2010 to study the effects of Quercus mongolica acorn quantity and rodent density on the seed dispersal of five tree species (Juglans mandshurica, Pinus koraiensis, Corylus mandshurica, Corylus heterophylla, and Q. mongolica). In the farm, there was an annual change in rodent density. The total capture rate of small rodents in 2009 (31.0%) was significantly higher than that in 2010 (16.7%). The acorn quantity and relative seed abundance (per capita rodent) of Quercus mongolica in 2009 (6.2 +/- 2.1 acorns x m(-2) and 20.0, respectively) were significantly lower than those in 2010 (26.7 +/- 10.2 acorns x m(-2) and 160.0, respectively). In 2009, all the seeds of the five tree species except J. mandshurica were dispersed or eaten in situ, among which, the acorns of Q. mongolica were scatter-hoarded most, and their average dispersal distance was the furthest. In 2010, the seeds of J. mandshurica were scatter-hoarded most, and their average dispersal distance was the furthest. The relative seed abundance of Q. mongolica could be the key factor determining the seed dispersal of the other tree species in the study area.

  14. Biomass dynamics of Quercus aliena var.acutesrata Community on Mountain Xiaolong in Gansu Province,China

    Institute of Scientific and Technical Information of China (English)

    Suo Anning; Ju Tianzhen; Zhang Junhua; Ge Jianping

    2006-01-01

    The dynamics of tree layer biomass was studied by combining 35 sample plots of field census with biomass model estimation in a natural Quercus aliena var.acutesrata community on Mountain Xiaolong in Gansu Province,China.The tree layer biomass of Quercus aliena var.acutesrata community was 183 660 kg/ha,in which the slow growth group accounted for 64.89% of the total biomass.The fast-medium growth group accounted for 33.40% and the coniferous group accounted for 1.38%.The organs biomass was found to be in the following order:trunk>root>branch>leaf.The total biomass accumulated with the development of the community.The total biomass and the biomass of the organs were highest in the mature community and became stable as the community developed.The relative growth rate of organs was in the following order:trunk>branch>root>leaf.The biomass ratio of the slow growth group trees tended to increase and the fast-medium group trees tended to decrease as the community developed,which was reveresed in the decline development stage.The biomass of the coniferous group was very small throughout the development process.

  15. Evaluation of Analgesic Activity of the Methanol Extract from the Galls of Quercus infectoria (Olivier in Rats

    Directory of Open Access Journals (Sweden)

    Sook-Ha Fan

    2014-01-01

    Full Text Available The present study aims to investigate the analgesic activity of the methanol extract of the galls of Quercus infectoria in rats using hot plate and tail-flick methods. The extract was administered intraperitoneally at a dose of 20 mg/kg while morphine sulfate and sodium salicylate (10 mg/kg served as standards. The methanol extract exhibited significant analgesic activity in the tail-flick model (P<0.05 by increasing the reaction time of the rats to 8.0 sec at 30 min after treatment in comparison to control (4.4 sec. Morphine sulfate produced a reaction time of 11.9 sec in the same test. At the peak of activity (30 min, the extract produced maximum possible analgesia (MPA of 34.2%, whilst morphine sulfate achieved a peak MPA of 70.9%. No analgesic effects have been observed using sodium salicylate in the tail-flick model. In the same model, the extract and sodium salicylate demonstrated comparable reaction times. Tail-flick is a better method to evaluate analgesic activity as no significant results were observed for all treatments using hot plate with the exception of morphine sulfate, which showed significant results only at 45 and 60 min after treatment. In conclusion, the methanol extract of the galls of Quercus infectoria displayed analgesic activity.

  16. Protective effect of Castanea sativa and Quercus robur leaf extracts against oxygen and nitrogen reactive species.

    Science.gov (United States)

    Almeida, Isabel F; Fernandes, Eduarda; Lima, José L F C; Costa, P C; Bahia, M F

    2008-05-29

    Topical natural antioxidants are a useful strategy for the prevention of photoaging and oxidative stress mediated skin diseases. In view of this underlying principle, the screening of natural plant extracts with scavenging activity for pro-oxidant reactive species is a primary requirement for the development of new topical antioxidant formulations. In the present study, an ethanol:water (7:3) extract from Castanea sativa leaves and a ethanol:water (2:3) extract from Quercus robur leaves were evaluated for their putative in vitro scavenging effects on reactive oxygen species (ROS) namely superoxide radical (O(2)(-)), hydroxyl radical (HO()), peroxyl radical (ROO()), hydrogen peroxide (H(2)O(2)) and singlet oxygen ((1)O(2)) as well as on reactive nitrogen species (RNS) namely nitric oxide (()NO) and peroxynitrite (ONOO(-)). The extracts presented a high potency to scavenge the tested reactive species, all the IC(50)s being found at the microg/mL level. IC(50)s (mean+/-SE) for the ROS O(2)(-),HO(),H(2)O(2) and (1)O(2) were 13.6+/-1.8; 216+/-4; 410+/-8; 12.3+/-0.7 microug/mL, respectively, for C. sativa, and 11.0+/-0.5; 285+/-22; 251+/-32; 7.90+/-0.56 microg/mL, respectively, for Q. robur. The ORAC values obtained for ROO() were 1.24+/-0.13 for C. sativa and 1.09+/-0.06 for Q. robur. The IC(50)s (mean+/-SE) for ()NO and ONOO(-) were 3.10+/-0.14 and 1.49+/-0.10 microg/mL, respectively, for C. sativa and 3.13+/-0.11 and 0.95+/-0.02 microg/mL, respectively, for Q. robur. The content of total phenolics for C. sativa and Q. robur were 284+/-9 and 346+/-4 mg of gallic acid equivalents (GAE)/g of lyophilized extract respectively. The observed effects might be of relevance considering the putative interest of these extracts as topical antioxidants.

  17. Drought impact on Quercus pubescens Willd. isoprene emissions over the Mediterranean area: what future?

    Science.gov (United States)

    Cyrielle Genard-Zielinski, Anne; Boissard, Christophe; Ormeño, Elena; Lathière, Juliette; Guenet, Bertrand; Gauquelin, Thierry; Fernandez, Catherine

    2015-04-01

    Biogenic Volatile Organic Compounds (BVOCs) released by plants mostly originate from their secondary metabolism. Their emissions are modulated, in terms of intensity and molecule diversity, by environmental conditions. Among BVOCs, isoprene has been especially studied due to its high emission fluxes and its contribution to tropospheric photochemistry, both in the gaseous and particulate phases. However, the way isoprene emissions are impacted by some abiotic factors, especially water stress, is still under debate. In a world facing climatic changes, global climate models expect air temperature and drought intensity to strengthen in the Mediterranean area by 2100. Our work focuses on the impact of water stress on isoprene emissions (ERiso) from Quercus pubescens Willd. This species covers large areas of the Mediterranean area where it appears to be the main isoprene emitter. An in situ experimentation was performed at the O3HP (Oak Observatory at OHP, southern France) in a pubescent oak forest with trees adapted to long lasting stress periods. We investigated during a whole seasonal cycle (from June 2012 to June 2013) the course of ERiso under both natural water stress (control treatment: C) and intensified water stress (stress treatment: S) by artificially reducing rain by 30% using a specific rain exclusion device. Restricted rain did not modify either the net CO2 assimilation or ERiso during the whole season. However, isoprene emission factors (Is) for trees under S were significantly higher (a factor of ˜ 2) than for trees growing under C in August (137.8 compared to 75.3 μgC.gDM-1.h-1 respectively) and September (75.3 compared to 40.2 μgC.gDM-1.h-1 respectively). Based on our experimental emission database, an appropriate isoprene emission algorithm (GZ2014) was developed using a statistic approach (an artificial neural network). Using ambient and edaphic environmental parameters integrated over up to 3 weeks, GZ2014 was found to represent more than 80% of

  18. Physiological Responses to Prolonged Drought Differ Among Three Oak (Quercus) Species

    Science.gov (United States)

    Cooper, C. E.; Moore, G. W.; Vogel, J. G.; Muir, J. P.

    2015-12-01

    The physiological response of plants to water stress provides insights into which species may survive in exceptional drought conditions. This study conducted on a remnant post oak savanna site in College Station, Texas, examined how drought affected the physiology of three native oak species. In June 2014, after a period of equal watering, we subjected three year old Quercus shumardii (Shumard oak; SO), Q. virginiana (live oak; LO), and Q. macrocarpa (bur oak; BO) saplings to one of two watering treatments: 1) watered, receiving the equivalent of theaverage precipitation rate and 2) droughted, receiving a 100% reduction in precipitation. We measured predawn (ΨPD) and midday (ΨMD) leaf water potential; midday gas exchange (MGE) parameters including photosynthesis (Al), transpiration (T), stomatal conductance (gsw); and leaf soluble (SS) and non-soluble sugar (NSS) concentrations monthly between June and October 2014. Drought stress responses were evident after only one month of induced drought. Droughted saplings showed reduced ΨPD, ΨMD, and MGE (P ≤ 0.05) in comparison to watered saplings of the same species. LO saplings exhibited greater MGE (P ≤ 0.05) while maintaining similar LWP to their respective watered and droughted BO and SO counterparts. Droughted LO exhibited MGE rates similar to those of watered BO and SO (P ≤ 0.05), while watered LO adjusted its MGE rates to changes in water availability better than BO and LO during short-term drought. Compared to water saplings, droughted saplings had greater leaf SS (P = 0.08) and lower NSS concentrations (P = 0.10), possibly due to the conversion of NSS to SS and other simple compounds and reduced consumption of SS for growth by the droughted saplings. Although SO and BO exhibited similar photosynthesis rates, leaf total sugar (SS+NSS) concentration was greater in SO (P ≤ 0.05). By displaying the greatest average photosynthesis rate (P ≤ 0.05), LO should have accumulated the greatest amount of carbon

  19. Species-specific climate response of oaks (Quercus spp. under identical environmental conditions

    Directory of Open Access Journals (Sweden)

    Sanders TGM

    2014-04-01

    Full Text Available Oak forests play a major role in Britain due to their economic, social and historic value. Sudden oak death and general decline symptoms have therefore caused major concerns in the forestry sector over the past decade. Several strategies have been proposed to preserve the economic and social value of oak forests, including the planting of native species with more southerly origins, or non-native species of oak that may be better suited to the projected climate of the future. The Ovington research plots, established 50 years ago at the Bedgebury Pinetum in southeast England, provided the opportunity to compare annual growth rates and climate-growth relationships of five oak species growing adjacent to each other on the same soil type and under the same climatic conditions. Clear differences were evident in annual increment and climate-growth responses for the five Quercus species. Growth rates were significantly lower (p<0.05 for the two species native to the UK (Q. petraea and Q. robur compared to the southern European and American species. A partitioning analysis using key climatic variables separates Q. coccinea from the other species due to its negative response to low temperatures. These results were confirmed by pointer year analysis. The analysis suggests that Q. robur is likely to be the more resilient of the two native species of oak to the future climate of southern Britain. Of the non-native species of oak evaluated, Q. coccinea represents an alternative species to Q. robur and Q. petraea on very dry, nutrient-poor sites. Q. palustris may also have some potential under current conditions for species diversification, but its requirement for higher summer precipitation than the other four species suggests that this potential may not be sustained as climate change progresses. However, if alternative species are selected as more resilient to climate change in terms of growth, it will be essential to consider a range of other issues

  20. Quercus robur vitality structure and its dynamics at the initial stages of ontogeny

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    V. M. Dehtiarov

    2015-07-01

    Full Text Available We present the results of evaluation of vitality structure of ontogenetic subcenopopulations of juvenile and immature (im1 and im2 plants Quercus robur L. in seven aggregations of forest vegetation of Krolevets-Hlukhiv Geobotanical Region. It is found that ontogenetic subcenopopulations of Q. robur young generation, formed under canopy of deciduous forests of the region under study, are noted for high level of vitality structure diversity and for having three qualitative types: blooming, balanced and depressive ones. It is observed that dynamics of Q quality index values in ontogenetic subcenopopulations Q. robur in the aggregations under study fits three variants of changes. In the first one we can see stable decrease of Q quality index values in the line j → im1 → im2. Three of seven aggregations under study have dynamics of Q index values fitting the variant where increase of values takes place in the phase j → im1, and their decrease occurs in the phase im1 → im2. Q index values also decrease in the phase j → im1 and their increase in the phase im1 → im2 is established in three more phytocenoces. It is proved that change to every next phase of development (from j to im1, and also from im1 to im2 is accompanied by the appearance of vitality plasticity in Q. robur young generation (i.e. Q quality index value changes and vitality variability (changes of share of individuals of various vitality classes, respectively. Quantitative as well as qualitative aspects of vitality plasticity realization are evaluated based on the original factor – index of vitality dynamics – IVD. It is found that at the initial stages of ontogenetic development negative changes of vitality structure in Q. robur happen more often then positive ones. Decrease in the individuals’ vitality and worsening of vitality structure are mainly accompanied by the reduction of cohort quality status. Ascertained facts as for vitality structure of ontogenetic

  1. Whole-transcriptome response to water stress in a California endemic oak, Quercus lobata.

    Science.gov (United States)

    Gugger, Paul F; Peñaloza-Ramírez, Juan Manuel; Wright, Jessica W; Sork, Victoria L

    2016-12-21

    Reduced water availability during drought can create major stress for many plant species. Within a species, populations with a history of seasonal drought may have evolved the ability to tolerate drought more than those in areas of high precipitation and low seasonality. In this study, we assessed response to water stress in a California oak species, Quercus lobata Née, by measuring changes in gene expression profiles before and after a simulated drought stress treatment through water deprivation of seedlings in a greenhouse setting. Using whole-transcriptome sequencing from nine samples from three collection localities, we identified which genes are involved in response to drought stress and tested the hypothesis that seedlings sampled from climatically different regions of the species range respond to water stress differently. We observed a surprisingly massive transcriptional response to drought: 35,347 of 68,434 contigs (52%) were differentially expressed before versus after drought treatment, of which 18,111 were down-regulated and 17,236 were up-regulated. Genes functionally associated with abiotic stresses and death were enriched among the up-regulated genes, whereas metabolic and cell part-related genes were enriched among the down-regulated. We found 56 contigs that exhibited significantly different expression responses to the drought treatment among the three populations (treatment × population interaction), suggesting that those genes may be involved in local adaptation to drought stress. These genes have stress response (e.g., WRKY DNA-binding protein 51 and HSP20-like chaperones superfamily protein), metabolic (e.g., phosphoglycerate kinase and protein kinase superfamily protein), transport/transfer (e.g., cationic amino acid transporter 7 and K(+) transporter) and regulatory functions (e.g., WRKY51 and Homeodomain-like transcriptional regulator). Baseline expression levels of 1310 unique contigs also differed among pairs of populations, and they

  2. <em>α>-Glucosidase Inhibitory Constituents from <em>Acanthopanax senticosusem> Harm Leaves

    Directory of Open Access Journals (Sweden)

    Hai-Xue Kuang

    2012-05-01

    Full Text Available A new triterpene glycoside, 3-<em>O-[(α>-L-rhamnopyranosyl(1→2]-[<em>β>-D-glucuronopyranosyl-6-<em>O>-methyl ester]-olean-12-ene-28-olic acid (1 and a new indole alkaloid, 5-methoxy-2-oxoindolin-3-acetic acid methyl ester (5 were isolated from the leaves of <em>Acanthopanax senticosusem> Harms along with six known compounds. The structures of the new compounds were determined by means of 2D-NMR experiments and chemical methods. All the isolated compounds were evaluated for their glycosidase inhibition activities and compound 6 showed significant <em>α>-glucosidase inhibition activity.

  3. Effects of drought and shade on growth and water use of Quercus alba, Q. bicolor, Q. imbricaria and Q. palustris seedlings

    Science.gov (United States)

    Joseph J. McCarthy; Jeffrey O. Dawson

    1991-01-01

    Growth and water use efficiency were determined for 2-year-old white oak (Quercus alba), swamp white oak (Q. imbricaria) and pin oak (Q. palustris) seedlings grown under three shade treatments (30, 55 and 73%) and two irrigation regimes (container capacity and mild drought). With species and water regimes...

  4. Drivers of radial growth and carbon isotope discrimination of bur oak (Quercus macrocarpa Michx.) across continental gradients in precipitation, vapour pressure deficit and irradiance

    Science.gov (United States)

    Steven L. Voelker; Frederick C. Meinzer; Barbara Lachenbruch; J. Renee Brooks; Richard P. Guyette

    2014-01-01

    Tree-ring characteristics are commonly used to reconstruct climate variables, but divergence from the assumption of a single biophysical control may reduce the accuracy of these reconstructions. Here, we present data from bur oaks (Quercus macrocarpa Michx.) sampled within and beyond the current species bioclimatic envelope to identify the primary...

  5. Experimental drought reduced acid and alkaline phosphatase activity and increased organic extractable P in soil in a Quercus ilex Mediterranean forest

    NARCIS (Netherlands)

    Sardans, J.; Penuelas, J.; Ogaya, R.

    2008-01-01

    A six-year (1999-2005) experiment of drought manipulation was conducted in a Quercus ilex Mediterranean forest (Southern Catalonia) to simulate predicted climatic conditions projected for the decades to come. The aim was to investigate the direct and indirect effects of drought conditions on acid an

  6. Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae)

    NARCIS (Netherlands)

    Quero Perez, J.L.; Villar, R.; Marañón, T.; Murillo, A.; Zamora, R.

    2008-01-01

    Light and water availability are two of the main factors that regulate growth and survival of Mediterranean woody plants. The objective of this study is to investigate the plastic response of seedlings of four Mediterranean Quercus species to these factors, as well as to determine what traits are

  7. Drought stress signals in modern and subfossil Quercus laurifolia (Fagaceae) leaves reflect winter precipitation in southern Florida tied to El Niño-Southern Oscillation activity

    NARCIS (Netherlands)

    Wagner-Cremer, F.; Donders, T.H.; Visscher, H.

    2010-01-01

    In the present study, structural xeromorphic features in modern and subfossil Quercus laurifolia leaves from southern Florida were quantified to reconstruct past precipitation changes in sensitive terrestrial settings. Absolute cell numbers/mm2, quantified as epidermal cell density (ED) h

  8. Influence of overstory density on ecophysiology of red oak (Quercus rubra) and sugar maple (Acer saccharum) seedlings in central Ontario shelterwoods

    Science.gov (United States)

    William C. Parker; Daniel C. Dey

    2008-01-01

    A field experiment was established in a secondgrowth hardwood forest dominated by red oak (Quercus rubra L.) to examine the effects of shelterwood overstory density on leaf gas exchange and seedling water status of planted red oak, naturally regenerated red oak and sugar maple (Acer saccharum Marsh.) seedlings during the first...

  9. The Occurrence of Charcoal Disease Caused by Biscogniauxia mediterranea on Chestnut-Leaved Oak (Quercus castaneifolia) in the Golestan Forests of Iran

    NARCIS (Netherlands)

    Mirabolfathy, M.; Groenewald, J.Z.; Crous, P.W.

    2011-01-01

    The chestnut-leaved oak (Quercus castaneifolia) is native to the Alborz Mountains, including the Golestan Forests, in northern Iran. Trees grow up to 35 (-50) m tall with a trunk up to 2.5 (-3.5) m in diameter. During 2010, we received reports of a decline of oak trees in the Ghorogh Region of the G

  10. Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae)

    NARCIS (Netherlands)

    Quero Perez, J.L.; Villar, R.; Marañón, T.; Murillo, A.; Zamora, R.

    2008-01-01

    Light and water availability are two of the main factors that regulate growth and survival of Mediterranean woody plants. The objective of this study is to investigate the plastic response of seedlings of four Mediterranean Quercus species to these factors, as well as to determine what traits are mo

  11. Three New Myrsinol Diterpenes from <em>Euphorbia proliferaem> and Their Neuroprotective Activities

    Directory of Open Access Journals (Sweden)

    Yuanqiang Guo

    2012-08-01

    Full Text Available Three new myrsinol diterpenes were isolated from the roots of<em> em>>Euphorbia proliferaem>. Their structures were elucidated as 2<em>α-O>-isobutyryl-3<em>β>,5<em>α>,7<em>β>,10,15<em>β-penta-O>-acetyl-14<em>α-O>-benzoyl-10,18-dihydromyrsinol (1, 2<em>α-O>-isobutyryl-3<em>β-O>-propion-yl-5<em>α>,7<em>β>,10,15<em>β-tetra-O>-acetyl-10,18-dihydromyrsinol (2, and 2<em>α>,14<em>α-di-O>-benzoyl-3<em>β>,5<em>α>,7<em>β>,10,15<em>β-penta-O>-acetyl-10,18-dihydromyrsinol (3 on the basis of spectroscopic data analyses (IR, ESI-MS, HR-ESI-MS, and 1D and 2D NMR. Their neuroprotective activities were evaluated and compounds 1 and 2 showed neuroprotective effects against MPP+-induced neuronal cell death in SH-SY5Y cells.

  12. Antimicrobial and antioxidative enrichment of oak (Quercus robur) bark by rotation planar extraction using ExtraChrom.

    Science.gov (United States)

    Andrensek, Samo; Simonovska, Breda; Vovk, Irena; Fyhrquist, Pia; Vuorela, Heikki; Vuorela, Pia

    2004-04-15

    The multifunctional ExtraChrom instrument was used in the extraction of antimicrobial and radical scavenging components from oak (Quercus robur L.) bark. Milled and sieved oak bark was extracted with 80% (v/v) methanol solution in water on the ExtraChrom instrument using step-gradient in the preparative separation. Extracts were tested using agar diffusion method on Staphylococcus aureus, Enterobacter aerogenes and Candida albicans. Some extracts showed moderate bactericidal, fungicidal, bacteriostatic and fungistatic activity. The composition related to activity of the fractions and extracts was screened simultaneously by thin-layer chromatography (TLC) detected by UV and by spraying the plate with radical scavenging reagent 1,1-diphenyl-2-picrylhydrazyl (DPPH) to detect antioxidant activity. Thus, we could demonstrate the antiradical and antimicrobial activity of oak beneficial in the storage of wine against the oxidation and human microbial exposure.

  13. Early growth of Quercus castaneifolia (C.A. Meyer) seedlings as affected by weeding, shading and irrigation.

    Science.gov (United States)

    Mirzaei, Javad; Tabari, Masoud; Daroodi, Hadi

    2007-08-01

    The influence of shading, irrigation and weeding on survival, growth and morphology of 1-year Quercus castaneifolia seedlings was studied in north of Iran. The seedlings were grown under eight treatments including full-light versus artificial shading, irrigation versus non-irrigation and weed presence versus weed removing at three replicates. At the end of the first growing season seedling survival in all treatments was 100%. Weed removing had positive effect on height, diameter growth, slenderness coefficient and leaf area of Q. castaneifolia. Irrigation enhanced diameter growth and leaf area and shading increased leaf area. Irrigation had no significant effect on plant growth where the weed was removed. In weed plots seedlings growth and leaf area were greater in shading than in full-light. The results indicated that for 1 year Q. castaneifolia seedlings, weeding, in contrast to irrigation, is an essential factor. Where the weed competition is a difficulty, plantation with higher stem length should be applied.

  14. Arquitectura foliar y anatomía de la corteza y la madera de Quercus sartorii y Q. xalapensis (Fagaceae)

    OpenAIRE

    Dorismilda Martínez Cabrera; Teresa Terrazas; Fernando Zavala Chávez

    2003-01-01

    En este trabajo se describe y compara la arquitectura foliar y la anatomía de la corteza y la madera de Quercus sartorii y Q. xalapensis, especies morfológicamente similares, en la búsqueda de caracteres que contribuyan a su delimitación. Los resultados mostraron que los caracteres del patrón de venación: número y forma de aréolas, ramificación de las vénulas y recorrido de la vena secundaria dentro del diente son caracteres que permiten distinguir a las especies, no así el tamaño de la hoja ...

  15. Variation of equilibrium moisture content of heat-treated Couratari oblongifolia, Fraxinus excelsior, and Quercus rubra wood

    Directory of Open Access Journals (Sweden)

    Qiaofang Zhou

    2013-02-01

    Full Text Available Heat treatment may result in variation of wood equilibrium moisture content (EMC. During this study, tauari (Couratari oblongifolia, ash (Fraxinus excelsior, and oak (Quercus rubra woods were heat-treated at 190, 200, and 210ºC for 3 hours and then put into a conditioning chamber with a temperature from 30 to 75ºC and a relative humidity from 50 to 90%. The isothermal moisture adsorption curve was subsequently analyzed. Results indicated that the EMC of heat-treated wood was reduced by 23.4 to 37.4% compared to non-treated wood, but the EMC difference at different heat-treated temperatures for three hardwoods was quite small and the EMC of heat-treated wood was inversely proportional to their dry density.

  16. Biomass-diversity relations of epiphytic bryophytes on small Quercus copeyensis stems in a Costa Rican montane cloud forest

    Directory of Open Access Journals (Sweden)

    H.J.F. Van Dunné

    1998-06-01

    Full Text Available Se muestreó briófitas epífitas sobre tallos pequeños de Quercus copeyensis Müll. en un bosque montano nuboso maduro (Talamanca, Costa Rica. Se muetreó a 0.8-1.8 m en cinco tallos (d.a.p. 1.8 -2.8 cm, hallándose 22 especies de musgos y 22 de hepáticas. La biomasa de briófitas ("briomasa" se correlacionó con la frecuencia, contribuyendo los musgos 54-99% . Un 14% de las especies contribuyó casi el 90% de la briomasa, sobresaliendo Pilotrichella flexilis (Hedw. Ångstr., Rigodium sp. 1, Porotrichodendron superbum (Taylor Broth., Prionodon densus (Hedw. Müll. Hal., Neckera chilensis Schimp. ex Mont. y Plagiochila guilleminiana Nees & Mont. Estas especies podrían jugar un papel importante en la regulación del flujo de agua.

  17. RNA-seq analysis of Quercus pubescens Leaves: de novo transcriptome assembly, annotation and functional markers development.

    Directory of Open Access Journals (Sweden)

    Sara Torre

    Full Text Available Quercus pubescens Willd., a species distributed from Spain to southwest Asia, ranks high for drought tolerance among European oaks. Q. pubescens performs a role of outstanding significance in most Mediterranean forest ecosystems, but few mechanistic studies have been conducted to explore its response to environmental constrains, due to the lack of genomic resources. In our study, we performed a deep transcriptomic sequencing in Q. pubescens leaves, including de novo assembly, functional annotation and the identification of new molecular markers. Our results are a pre-requisite for undertaking molecular functional studies, and may give support in population and association genetic studies. 254,265,700 clean reads were generated by the Illumina HiSeq 2000 platform, with an average length of 98 bp. De novo assembly, using CLC Genomics, produced 96,006 contigs, having a mean length of 618 bp. Sequence similarity analyses against seven public databases (Uniprot, NR, RefSeq and KOGs at NCBI, Pfam, InterPro and KEGG resulted in 83,065 transcripts annotated with gene descriptions, conserved protein domains, or gene ontology terms. These annotations and local BLAST allowed identify genes specifically associated with mechanisms of drought avoidance. Finally, 14,202 microsatellite markers and 18,425 single nucleotide polymorphisms (SNPs were, in silico, discovered in assembled and annotated sequences. We completed a successful global analysis of the Q. pubescens leaf transcriptome using RNA-seq. The assembled and annotated sequences together with newly discovered molecular markers provide genomic information for functional genomic studies in Q. pubescens, with special emphasis to response mechanisms to severe constrain of the Mediterranean climate. Our tools enable comparative genomics studies on other Quercus species taking advantage of large intra-specific ecophysiological differences.

  18. Spatial Segregation and Aggregation of Ectomycorrhizal and Root-Endophytic Fungi in the Seedlings of Two Quercus Species

    Science.gov (United States)

    Yamamoto, Satoshi; Sato, Hirotoshi; Tanabe, Akifumi S.; Hidaka, Amane; Kadowaki, Kohmei; Toju, Hirokazu

    2014-01-01

    Diverse clades of mycorrhizal and endophytic fungi are potentially involved in competitive or facilitative interactions within host-plant roots. We investigated the potential consequences of these ecological interactions on the assembly process of root-associated fungi by examining the co-occurrence of pairs of fungi in host-plant individuals. Based on massively-parallel pyrosequencing, we analyzed the root-associated fungal community composition for each of the 249 Quercus serrata and 188 Quercus glauca seedlings sampled in a warm-temperate secondary forest in Japan. Pairs of fungi that co-occurred more or less often than expected by chance were identified based on randomization tests. The pyrosequencing analysis revealed that not only ectomycorrhizal fungi but also endophytic fungi were common in the root-associated fungal community. Intriguingly, specific pairs of these ectomycorrhizal and endophytic fungi showed spatially aggregated patterns, suggesting the existence of facilitative interactions between fungi in different functional groups. Due to the large number of fungal pairs examined, many of the observed aggregated/segregated patterns with very low P values (e.g., fungi could influence each other through interspecific competitive/facilitative interactions in root. To test the potential of host-plants' control of fungus–fungus ecological interactions in roots, we further examined whether the aggregated/segregated patterns could vary depending on the identity of host plant species. Potentially due to the physiological properties shared between the congeneric host plant species, the sign of hosts' control was not detected in the present study. The pyrosequencing-based randomization analyses shown in this study provide a platform of the high-throughput investigation of fungus–fungus interactions in plant root systems. PMID:24801150

  19. Application of plant DNA markers in forensic botany: genetic comparison of Quercus evidence leaves to crime scene trees using microsatellites.

    Science.gov (United States)

    Craft, Kathleen J; Owens, Jeffrey D; Ashley, Mary V

    2007-01-05

    As highly polymorphic DNA markers become increasingly available for a wide range of plant and animal species, there will be increasing opportunities for applications to forensic investigations. To date, however, relatively few studies have reported using DNA profiles of non-human species to place suspects at or near crime scenes. Here we describe an investigation of a double homicide of a female and her near-term fetus. Leaf material taken from a suspect's vehicle was identified to be that of sand live oak, Quercus geminata, the same tree species that occurred near a shallow grave where the victims were found. Quercus-specific DNA microsatellites were used to genotype both dried and fresh material from trees located near the burial site and from the material taken from the suspect's car. Samples from the local population of Q. geminata were also collected and genotyped in order to demonstrate that genetic variation at four microsatellite loci was sufficient to assign leaves to an individual tree with high statistical certainty. The cumulative average probability of identity for these four loci was 2.06x10(-6). DNA was successfully obtained from the dried leaf material although PCR amplification was more difficult than amplification of DNA from fresh leaves. The DNA profiles of the dried leaves from the suspect's car did not match those of the trees near the crime scene. Although this investigation did not provide evidence that could be used against the suspect, it does demonstrate the potential for plant microsatellite markers providing physical evidence that links plant materials to live plants at or near crime scenes.

  20. Spatial segregation and aggregation of ectomycorrhizal and root-endophytic fungi in the seedlings of two Quercus species.

    Science.gov (United States)

    Yamamoto, Satoshi; Sato, Hirotoshi; Tanabe, Akifumi S; Hidaka, Amane; Kadowaki, Kohmei; Toju, Hirokazu

    2014-01-01

    Diverse clades of mycorrhizal and endophytic fungi are potentially involved in competitive or facilitative interactions within host-plant roots. We investigated the potential consequences of these ecological interactions on the assembly process of root-associated fungi by examining the co-occurrence of pairs of fungi in host-plant individuals. Based on massively-parallel pyrosequencing, we analyzed the root-associated fungal community composition for each of the 249 Quercus serrata and 188 Quercus glauca seedlings sampled in a warm-temperate secondary forest in Japan. Pairs of fungi that co-occurred more or less often than expected by chance were identified based on randomization tests. The pyrosequencing analysis revealed that not only ectomycorrhizal fungi but also endophytic fungi were common in the root-associated fungal community. Intriguingly, specific pairs of these ectomycorrhizal and endophytic fungi showed spatially aggregated patterns, suggesting the existence of facilitative interactions between fungi in different functional groups. Due to the large number of fungal pairs examined, many of the observed aggregated/segregated patterns with very low P values (e.g., fungi could influence each other through interspecific competitive/facilitative interactions in root. To test the potential of host-plants' control of fungus-fungus ecological interactions in roots, we further examined whether the aggregated/segregated patterns could vary depending on the identity of host plant species. Potentially due to the physiological properties shared between the congeneric host plant species, the sign of hosts' control was not detected in the present study. The pyrosequencing-based randomization analyses shown in this study provide a platform of the high-throughput investigation of fungus-fungus interactions in plant root systems.

  1. Using common mycorrhizal networks for controlled inoculation of Quercus spp. with Tuber melanosporum: the nurse plant method.

    Science.gov (United States)

    Pereira, Guillermo; Palfner, Götz; Chávez, Daniel; Suz, Laura M; Machuca, Angela; Honrubia, Mario

    2013-07-01

    The high cost and restricted availability of black truffle spore inoculum for controlled mycorrhiza formation of host trees produced for truffle orchards worldwide encourage the search for more efficient and sustainable inoculation methods that can be applied globally. In this study, we evaluated the potential of the nurse plant method for the controlled inoculation of Quercus cerris and Quercus robur with Tuber melanosporum by mycorrhizal networks in pot cultures. Pine bark compost, adjusted to pH 7.8 by liming, was used as substrate for all assays. Initially, Q. robur seedlings were inoculated with truffle spores and cultured for 12 months. After this period, the plants presenting 74 % mycorrhizal fine roots were transferred to larger containers. Nurse plants were used for two treatments of two different nursling species: five sterilized acorns or five 45-day-old, axenically grown Q. robur or Q. cerris seedlings, planted in containers around the nurse plant. After 6 months, colonized nursling plant root tips showed that mycorrhiza formation by T. melanosporum was higher than 45 % in the seedlings tested, with the most successful nursling combination being Q. cerris seedlings, reaching 81 % colonization. Bulk identification of T. melanosporum mycorrhizae was based on morphological and anatomical features and confirmed by sequencing of the internal transcribed spacer region of the ribosomal DNA of selected root tips. Our results show that the nurse plant method yields attractive rates of mycorrhiza formation by the Périgord black truffle and suggest that establishing and maintaining common mycorrhizal networks in pot cultures enables sustained use of the initial spore inoculum.

  2. Abundancia y distribución de agallas foliosas en Quercus resinosa Liemb. (Fagaceae en Aguascalientes, México

    Directory of Open Access Journals (Sweden)

    Ricardo Clark-Tapia

    2015-08-01

    Full Text Available Las agallas son estructuras de crecimiento anormal en los tejidos de las plantas debido a la actividad parasítica de otro organismo. El estudio de este tipo de estructuras como microhábitat de avispas es escaso en la literatura y no se presenta una descripción detallada de su conformación. En este trabajo se describe la anatomía y morfología de las agallas foliosas, y se evalúan los factores que restringen su abundancia y distribución a nivel foliar, individual y poblacional en los encinosQuercus resinosa. Se encontró que la agalla es generada por una avispa de la familia Cynipidae, específica deQuercus resinosaLiemb. A nivel foliar, las agallas presentan características anatómicas y morfológicas similares a las del hospedero. A nivel del individuo, el 72.52% de las agallas están ubicadas en el envés de la hoja, mientras que sólo el 27.48% de estas estructuras se forman en el haz. A nivel de la población, el número de agallas varía de una a diez agallas por árbol. En promedio, cada árbol puede tener 4.88 ± 2.34 agallas. Los árboles mayormente infectados son los de categorías intermedias (X2=9.67; P

  3. Does animal-mediated seed dispersal facilitate the formation of Pinus armandii-Quercus aliena var. acuteserrata forests?

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    Fei Yu

    Full Text Available The Pinus armandii and Quercus aliena var. acuteserrata mixed forest is one of the major forest types in the Qinling Mountains, China. P. armandii is considered to be a pioneer species during succession and it is usually invaded by late successional Q. aliena var. acuteserrata. However, the mechanism that underlies its invasion remains unclear. In the present study, we tracked seed dispersal of P. armandii and Q. aliena var. acuteserrata using coded plastic tags in the western, middle and eastern Qinling Mountains to elucidate the invasion process in the mixed forests. Our results indicated that the seeds of both P. armandii and Q. aliena var. acuteserrata were removed rapidly in the Qinling Mountains, and there were no differences in the seed removal rates between the two species. There were significant differences in rodent seed-eating and caching strategies between the two tree species. For P. armandii, seeds were more likely to be eaten in situ than those of Q. aliena var. acuteserrata in all plots. By contrast, the acorns of Q. aliena var. acuteserrata were less frequently eaten in situ, but more likely to be removed and cached. Q. aliena var. acuteserrata acorns had significantly longer dispersal distances than P. armandii seeds in all plots. Although P. armandii seeds were less likely to be dispersed into the Q. aliena var. acuteserrata stands, over 30% of the released acorns were transported into the P. armandii stands where they established five seedlings. Based on the coupled recruitment patterns of P. armandii and Q. aliena var. acuteserrata, we suggest that the animal-mediated seed dispersal contributes to the formation of Pinus armandii-Quercus aliena var. acuteserrata forests.

  4. Tree species richness, diversity, and regeneration status in different oak (Quercus spp. dominated forests of Garhwal Himalaya, India

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    Sushma Singh

    2016-09-01

    Full Text Available Himalayan forests are dominated by different species of oaks (Quercus spp. at different altitudes. These oaks are intimately linked with hill agriculture as they protect soil fertility, watershed, and local biodiversity. They also play an important role in maintaining ecosystem stability. This work was carried out to study the diversity and regeneration status of some oak forests in Garhwal Himalaya, India. A total of 18 tree species belonging to 16 genera and 12 families were reported from the study area. Species richness varied for trees (4–7, saplings (3–10, and seedlings (2–6. Seedling and sapling densities (Ind/ha varied between 1,376 Ind/ha and 9,600 Ind/ha and 167 Ind/ha and 1,296 Ind/ha, respectively. Species diversity varied from 1.27 to 1.86 (trees, from 0.93 to 3.18 (saplings, and from 0.68 to 2.26 (seedlings. Total basal area (m2/ha of trees and saplings was 2.2–87.07 m2/ha and 0.20–2.24 m2/ha, respectively, whereas that of seedlings varied from 299 cm2/ha to 8,177 cm2/ha. Maximum tree species (20–80% had “good” regeneration. Quercus floribunda, the dominant tree species in the study area, showed “poor” regeneration, which is a matter of concern, and therefore, proper management and conservation strategies need to be developed for maintenance and sustainability of this oak species along with other tree species that show poor or no regeneration.

  5. Neonatal Phosphate Nutrition Alters <em>in em>Vivo> and <em>in em>Vitro> Satellite Cell Activity in Pigs

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    Chad H. Stahl

    2012-05-01

    Full Text Available Satellite cell activity is necessary for postnatal skeletal muscle growth. Severe phosphate (PO4 deficiency can alter satellite cell activity, however the role of neonatal PO4 nutrition on satellite cell biology remains obscure. Twenty-one piglets (1 day of age, 1.8 ± 0.2 kg BW were pair-fed liquid diets that were either PO4 adequate (0.9% total P, supra-adequate (1.2% total P in PO4 requirement or deficient (0.7% total P in PO4 content for 12 days. Body weight was recorded daily and blood samples collected every 6 days. At day 12, pigs were orally dosed with BrdU and 12 h later, satellite cells were isolated. Satellite cells were also cultured <em>in vitroem> for 7 days to determine if PO4 nutrition alters their ability to proceed through their myogenic lineage. Dietary PO4 deficiency resulted in reduced (<em>P> < 0.05 sera PO4 and parathyroid hormone (PTH concentrations, while supra-adequate dietary PO4 improved (<em>P> < 0.05 feed conversion efficiency as compared to the PO4 adequate group. <em>In vivoem> satellite cell proliferation was reduced (<em>P> < 0.05 among the PO4 deficient pigs, and these cells had altered <em>in vitroem> expression of markers of myogenic progression. Further work to better understand early nutritional programming of satellite cells and the potential benefits of emphasizing early PO4 nutrition for future lean growth potential is warranted.

  6. Tendencias en la investigación sobre ecología y gestión de las especies de Quercus

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    T. Marañón

    2014-01-01

    Full Text Available El género Quercus reúne algunas de las especies arbóreas más relevantes en los bosques del hemisferio norte, tanto por su amplia distribución geográfica como por su gran importancia ecológica y económica. Algunas de estas especies han sido y continúan siendo foco central en numerosos estudios científicos relacionados con la ecología y gestión de ecosistemas forestales. Los objetivos de este artículo son: 1 conocer la evolución del número de artículos relacionados con Quercus, así como los países y autores con mayor producción científica en este campo, 2 identificar los principales temas de investigación sobre las especies de Quercus de España y 3 discutir los huecos en el conocimiento y proponer algunas líneas futuras de investigación. Según la base de datos ISI Web of Science se han publicado 13 469 artículos relacionados con las especies de Quercus, con un crecimiento exponencial a lo largo del tiempo. España ocupa el segundo lugar en cuanto a número de artículos publicados (11.6 % del total, después de los Estados Unidos. Entre los 24 090 autores de artículos relacionados con Quercus, cinco españoles se encuentran entre los 20primeros en número de publicaciones. Dentro de las publicaciones sobre Quercus en España, la especie con mayor interés es la encina (Q. ilex,46.5 % de los artículos y los temas a los que se ha prestado más atención son: el cambio climático, la regeneración, los efectos de la sequía, las perturbaciones y la riqueza de especies. Se discuten los huecos de conocimiento detectados (en base a encuestas de expertos y se proponen líneas de investigación futuras relacionadas con el cambio global, la demografía, la eco fisiología, las interacciones bióticas y la gestión.

  7. The taxonomy of the Japanese oak red scale insect, Kuwania quercus (Kuwana) (Hemiptera: Coccoidea: Kuwaniidae), with a generic diagnosis, a key to species and description of a new species from California.

    Science.gov (United States)

    San'An, Wu; Nan, Nan; Gullan, Penny; Deng, Jun

    2013-01-01

    The oak red scale insect, Kuwania quercus (Kuwana), was described from specimens collected from the bark of oak trees (Quercus species) in Japan. More recently, the species has been identified from California and China, but Californian specimens differ morphologically from Japanese material and are considered here to be a new species based on both morphological and molecular data. In this paper, an illustrated redescription of K. quercus is provided based on type specimens consisting of adult females, first-instar nymphs and intermediate-stage females, and a lectotype is designated for Sasakia quercus Kuwana. The new Californian species, Kuwania raygilli Wu & Gullan, is described and illustrated based on the adult female, first-instar nymph and intermediate-stage female. A new generic diagnosis for Kuwania Cockerell based on adult females and first-instar nymphs, and a key to species based on adult females are included.

  8. Constituents from <em>Vigna em>vexillata> and Their Anti-Inflammatory Activity

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    Guo-Feng Chen

    2012-08-01

    Full Text Available The seeds of <em>Vigna em>genus are important food resources and there have already been many reports regarding their bioactivities. In our preliminary bioassay, the chloroform layer of methanol extracts of<em> V. vexillata em>demonstrated significant anti-inflammatory bioactivity. Therefore, the present research is aimed to purify and identify the anti-inflammatory principles of <em>V. vexillataem>. One new sterol (1 and two new isoflavones (2,3 were reported from the natural sources for the first time and their chemical structures were determined by the spectroscopic and mass spectrometric analyses. In addition, 37 known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. Among the isolates, daidzein (23, abscisic acid (25, and quercetin (40 displayed the most significant inhibition of superoxide anion generation and elastase release.

  9. Sap flow measurements combining sap-flux density radial profiles with punctual sap-flux density measurements in oak trees (Quercus ilex and Quercus pyrenaica) - water-use implications in a water-limited savanna-

    Science.gov (United States)

    Reyes, J. Leonardo; Lubczynski1, Maciek W.

    2010-05-01

    Sap flow measurement is a key aspect for understanding how plants use water and their impacts on the ecosystems. A variety of sensors have been developed to measure sap flow, each one with its unique characteristics. When the aim of a research is to have accurate tree water use calculations, with high temporal and spatial resolution (i.e. scaled), a sensor with high accuracy, high measurement efficiency, low signal-to-noise ratio and low price is ideal, but such has not been developed yet. Granier's thermal dissipation probes (TDP) have been widely used in many studies and various environmental conditions because of its simplicity, reliability, efficiency and low cost. However, it has two major flaws when is used in semi-arid environments and broad-stem tree species: it is often affected by high natural thermal gradients (NTG), which distorts the measurements, and it cannot measure the radial variability of sap-flux density in trees with sapwood thicker than two centimeters. The new, multi point heat field deformation sensor (HFD) is theoretically not affected by NTG, and it can measure the radial variability of the sap flow at different depths. However, its high cost is a serious limitation when simultaneous measurements are required in several trees (e.g. catchment-scale studies). The underlying challenge is to develop a monitoring schema in which HFD and TDP are combined to satisfy the needs of measurement efficiency and accuracy in water accounting. To assess the level of agreement between TDP and HFD methods in quantifying sap flow rates and temporal patterns on Quercus ilex (Q.i ) and Quercus pyrenaica trees (Q.p.), three measurement schemas: standard TDP, TDP-NTG-corrected and HFD were compared in dry season at the semi-arid Sardon area, near Salamanca in Spain in the period from June to September 2009. To correct TDP measurements with regard to radial sap flow variability, a radial sap flux density correction factor was applied and tested by adjusting TDP

  10. The Antimicrobial Efficacy of <em>Elaeis guineensisem>: Characterization, <em>in Vitroem> and <em>in Vivoem> Studies

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    Sreenivasan Sasidharan

    2012-04-01

    Full Text Available The urgent need to treat multi-drug resistant pathogenic microorganisms in chronically infected patients has given rise to the development of new antimicrobials from natural resources. We have tested <em>Elaeis guineensis em>Jacq> em>(Arecaceae methanol extract against a variety of bacterial, fungal and yeast strains associated with infections. Our studies have demonstrated that <em>E. guineensisem> exhibits excellent antimicrobial activity <em>in vitroem> and <em>in vivoem> against the bacterial and fungal strains tested. A marked inhibitory effect of the <em>E. guineensisem> extracts was observed against <em>C. albicansem> whereby <em>E. guineensisem> extract at ½, 1, or 2 times the MIC significantly inhibited <em>C. albicansem> growth with a noticeable drop in optical density (OD of the bacterial culture. This finding confirmed the anticandidal activity of the extract on <em>C. albicansem>. Imaging using scanning (SEM and transmission (TEM electron microscopy was done to determine the major alterations in the microstructure of the extract-treated <em>C. albicansem>. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the yeast cells. <em>In vivoem> antimicrobial activity was studies in mice that had been inoculated with <em>C. albicansem> and exhibited good anticandidal activity. The authors conclude that the extract may be used as a candidate for the development of anticandidal agent.<em> em>

  11. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia

    DEFF Research Database (Denmark)

    Costa, A.; Madeira, M.; Lima Santos, J.

    2014-01-01

    Mediterranean evergreen oak woodlands (composed of Quercus suber L. and Quercus rotundifolia Lam.) are becoming increasingly fragmented in the human-modified landscapes of Southwestern Portugal and Spain. Previous studies have largely neglected to assess the spatial changes of oak woodlands in re...

  12. Comparison of the autoecology of Quercus robur L. and Q. petraea (Mattuschka Liebl. stands in the Northwest of the Iberian Peninsula

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    A. Rodriguez-Campos

    2010-09-01

    Full Text Available The purpose of the present work is to characterize the functioning of the ecosystems of semideciduous and deciduous Atlantic oaks in the northwest of the Iberian Peninsula. The studied species were: Quercus robur L. and Quercus petraea (Mattuschka Liebl. To advance in the knowledge of the autecology of these species it is necessary to descend at the regional level and describe in detail the variability of the environment to determine their potential, and to decide the silvicultural treatments to be applied to preserve them and to analyze future actuations in order to a possible expansion. The analysis of the results allows knowing differences in continentalityand site conditions, with more precipitation, soil variability and humidification in Q. petraea forests respect to Q. robur. These information represent appropriate measures for the sustainable and multifunctional management of these forests, useful as indicators environmental and forestry parameters as well as the conservationstatus of these formations.

  13. Datos históricos de la presencia de fitónimos relacionados con el género Quercus L. en Canarias

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    Marcos Salas Pascual

    2013-11-01

    Full Text Available En el presente trabajo se discute la posible presencia histórica de algunas especies del género Quercus L. en Canarias. Se utilizan para ello referencias documentales y toponímicas, así como citas botánicas antiguas. De esta manera se plantea la posibilidad de que existiesen poblaciones distintas especies de este género en Fuerteventura y Tenerife.Presently work is discussed the possible historical presence of some species of the gender Quercus L. in Canarias. They are used for this toponimic and documental references, as well as botanical old appointments. This way thinks about the possibility that some species of this gender could grow in Fuerteventura and Tenerife.

  14. The Geographic Distribution of a Tropical Montane Bird Is Limited by a Tree: Acorn Woodpeckers (Melanerpes formicivorus) and Colombian Oaks (Quercus humboldtii) in the Northern Andes.

    Science.gov (United States)

    Freeman, Benjamin G; Mason, Nicholas A

    2015-01-01

    Species distributions are limited by a complex array of abiotic and biotic factors. In general, abiotic (climatic) factors are thought to explain species' broad geographic distributions, while biotic factors regulate species' abundance patterns at local scales. We used species distribution models to test the hypothesis that a biotic interaction with a tree, the Colombian oak (Quercus humboldtii), limits the broad-scale distribution of the Acorn Woodpecker (Melanerpes formicivorus) in the Northern Andes of South America. North American populations of Acorn Woodpeckers consume acorns from Quercus oaks and are limited by the presence of Quercus oaks. However, Acorn Woodpeckers in the Northern Andes seldom consume Colombian oak acorns (though may regularly drink sap from oak trees) and have been observed at sites without Colombian oaks, the sole species of Quercus found in South America. We found that climate-only models overpredicted Acorn Woodpecker distribution, suggesting that suitable abiotic conditions (e.g. in northern Ecuador) exist beyond the woodpecker's southern range margin. In contrast, models that incorporate Colombian oak presence outperformed climate-only models and more accurately predicted the location of the Acorn Woodpecker's southern range margin in southern Colombia. These findings support the hypothesis that a biotic interaction with Colombian oaks sets Acorn Woodpecker's broad-scale geographic limit in South America, probably because Acorn Woodpeckers rely on Colombian oaks as a food resource (possibly for the oak's sap rather than for acorns). Although empirical examples of particular plants limiting tropical birds' distributions are scarce, we predict that similar biotic interactions may play an important role in structuring the geographic distributions of many species of tropical montane birds with specialized foraging behavior.

  15. Efficient Heterologous Transformation of <em>Chlamydomonas> reinhardtiiem> <em>npq2em> Mutant with the Zeaxanthin Epoxidase Gene Isolated and Characterized from<em> Chlorella zofingiensisem>

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    Herminia Rodríguez

    2012-09-01

    Full Text Available In the violaxanthin cycle, the violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the inter-conversion between violaxanthin and zeaxanthin in both plants and green algae. The zeaxanthin epoxidase gene from the green microalga <em>Chlorella zofingiensisem> (<em>Czzep> has been isolated<em>. em>This gene encodes a polypeptide of 596 amino acids. A single copy of <em>Czzep> has been found in the <em>C. zofingiensisem> genome by Southern blot analysis. qPCR analysis has shown that transcript levels of <em>Czzep> were increased after zeaxanthin formation under high light conditions. The functionality of <em>Czzep> gene by heterologous genetic complementation in the <em>Chlamydomonas> mutant <em>npq2em>, which lacks zeaxanthin epoxidase (ZEP activity and accumulates zeaxanthin in all conditions, was analyzed. The <em>Czzep> gene was adequately inserted in the pSI105 vector and expressed in <em>npq2em>. The positive transformants were able to efficiently convert zeaxanthin into violaxanthin, as well as to restore their maximum quantum efficiency of the PSII (Fv/Fm. These results show that <em>Chlamydomonas> can be an efficient tool for heterologous expression and metabolic engineering for biotechnological applications.

  16. Development of gypsy moth (Lymantria dispar L on the foliage of Quercus cerris L., Q. Petraea (matt Liebl. and Q. Robur L. in the controlled conditions

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    Milanović Slobodan

    2007-01-01

    Full Text Available The development of Gypsy moth (Lymantria dispar L was monitored in laboratory conditions, on the foliage of the species Quercus cerris L. Quercus petraea (Matt Liebl. and Quercus robur L. The experiment was established in the controlled environmental conditions, at the temperature of 25°C, photoperiod 14:10 (day: night and relative humidity 70%. The objective of the research was to determine the suitability of the study host plant species for gypsy moth development. The study results show that Gypsy moth caterpillars cultivated on Q. petraea foliage had a lower survival, higher number of moultings, longer preadult development and lower fecundity, which makes this species less suitable compared to the other two. Gypsy moth caterpillars cultivated on Q. cerris foliage had the highest survival degree the lowest number of moultings, the shortest preadult development and the highest fecundity, which makes this species the most favourable for gypsy moth development. Q. robur was between the former two species in this respect.

  17. Redimiento de Quercus humboldtii Bonpland (Roble en condiciones de interacción micorrizas ectotróficas - humus

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    Zarate Quiroga Lyda Minelly

    2002-11-01

    Full Text Available Se evaluó el rendimiento de Quercus humboldtii(roble en hidroponía de soporte sólido (virutade madera a través del análisis de las variables peso seco (g, peso fresco (g, altura (cm, áreafoliar (cm2, índice foliar específico (IF, cm2/g y tasa de asimilación neta (TAN, g/cm2*días,en dos fases, durante 14 meses, así: en la fase 1 (10 meses se aplicó inóculo ectomicorrízico,posteriormente se comprobó la colonización por ectomicorrizas (ECM. Se encontró diferenciaestadísticamente significativa (95% de confianza entre los 2 tratamientos (con y sin ECM, endonde las plantas ectomicorrizadas presentan incrementos en las variables evaluadas. En lafase 2 (4 meses, se adicionaron 5 humus, disímiles en los contenidos de elementos y pH, perocon valores de capacidad de intercambio catiónico (CIC altos (superiores a 25 meq/100g.A los tratamientos (12, resultado de combinar árboles con y sin ECM con cada uno de loshumus, se les confirmó la presencia de ECM y mostraron diferencias significativas (95% deconfianza, en donde se vió que la interacción ECM - humus genera los mejores rendimientos,y que la ectomicorriza actúa como reguladora de los cambios en la disponibilidad de elementosen el medio. Los análisis de elementos a nivel foliar mostraron una amplia tolerancia del roblepara macro y micro elementos, desde valores bajos a altos, según los referentes empleados. Seestableció un sistema interactuante soporte - raíz - ECM - humus, que permite una adecuadadinámica nutricional. Se analizó el inóculo ectomicorrízico (obtenido de árboles en condicionesde campo, y se obtuvo por morfotipificación la caracterización de 12 morfotipos, más uno delensayo de rendimiento. Al contrastar los morfotipos obtenidos con los árboles fuente se corro-boró el comportamiento poli-simbióntico de la especie. Se encontraron las condiciones necesa-rias para establecer hidroponía en medio líquido de Quercus humboldtii.

  18. Dermatoses em renais cronicos em terapia dialitica

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    Luis Alberto Batista Peres

    2014-03-01

    Full Text Available Objetivo: As desordens cutâneas e das mucosas são comuns em pacientes em hemodiálise a longo prazo. A diálise prolonga a expectativa de vida, dando tempo para a manifestação destas anormalidades. Os objetivos deste estudo foram avaliar a prevalência de problemas dermatológicos em pacientes com doença renal crônica (DRC em hemodiálise. Métodos: Cento e quarenta e cinco pacientes com doença renal crônica em hemodiálise foram estudados. Todos os pacientes foram completamente analisados para as alterações cutâneas, de cabelos, mucosas e unhas por um único examinador e foram coletados dados de exames laboratoriais. Os dados foram armazenados em um banco de dados do Microsolft Excel e analisados por estatística descritiva. As variáveis contínuas foram comparadas pelo teste t de Student e as variáveis categóricas utilizando o teste do qui-quadrado ou o teste Exato de Fischer, conforme adequado. Resultados: O estudo incluiu 145 pacientes, com idade média de 53,6 ± 14,7 anos, predominantemente do sexo masculino (64,1% e caucasianos (90,0%. O tempo médio de diálise foi de 43,3 ± 42,3 meses. As principais doenças subjacentes foram: hipertensão arterial em 33,8%, diabetes mellitus em 29,6% e glomerulonefrite crônica em 13,1%. As principais manifestações dermatológicas observadas foram: xerose em 109 (75,2%, equimose em 87 (60,0%, prurido em 78 (53,8% e lentigo em 33 (22,8% pacientes. Conclusão: O nosso estudo mostrou a presença de mais do que uma dermatose por paciente. As alterações cutâneas são frequentes em pacientes em diálise. Mais estudos são necessários para melhor caracterização e manejo destas dermatoses.

  19. Mycorrhizal status of several Quercus species in Romania (Quercus cerris, Q. frainetto, Q. robur and the optimization perspective of growth conditions for in vitro propagated plants transplanted in the field

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available There is an increasing interest for important tree species conservation in the context of climate change, anthropogenic pressure and invasion of alien tree species. A key factor in the survival of trees is represented by the mycorrhizal association. The success of micropropagated trees also depends on the acquisition of mycorrhizal mutualists. Ectomycorrhizal roots samples from several Quercus species (Q. cerris, Q. frainetto, Q. robur were examined for mycorrhizal morphotypes’ characterization. The samples were collected during the vegetation season from stands located in Southern and North-Western Romania. 30 morphotypes of active mycorrhizae were identified with Cenococcum geophilumFr. (Ascomycota as dominating morphotype. Previous studies on somatic embryogenesis in Q. roburand Q. frainetto demonstrated the utility of in vitro techniques in obtaining plants from these recalcitrant seed producing species, considered at risk in various areas of the country, due to increasingly stressful conditions. The success rate of the acclimatization process depends on the mycorrhization performed either artificially, in the laboratory, either naturally, in the field. Ex situ mycorrhization solutions are considered as less costly, yet efficient alternative to improve the ex vitro survival of micropropagated plants or endangered tree species or for those with economic importance, in vitro propagation is an important conservation tool combined with the acquisition of appropriate mycorrhizal mutualists. 

  20. Mycorrhizal status of several Quercus species in Romania (Quercus cerris, Q. frainetto, Q. robur and the optimization perspective of growth conditions for in vitro propagated plants transplanted in the field

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available There is an increasing interest for important tree species conservation in the context of climate change, anthropogenic pressure and invasion of alien tree species. A key factor in the survival of trees is represented by the mycorrhizal association. The success of micropropagated trees also depends on the acquisition of mycorrhizal mutualists. Ectomycorrhizal roots samples from several Quercus species (Q. cerris, Q. frainetto, Q. robur were examined for mycorrhizal morphotypes’ characterization. The samples were collected during the vegetation season from stands located in Southern and North-Western Romania. 30 morphotypes of active mycorrhizae were identified with Cenococcum geophilumFr. (Ascomycota as dominating morphotype. Previous studies on somatic embryogenesis in Q. roburand Q. frainetto demonstrated the utility of in vitro techniques in obtaining plants from these recalcitrant seed producing species, considered at risk in various areas of the country, due to increasingly stressful conditions. The success rate of the acclimatization process depends on the mycorrhization performed either artificially, in the laboratory, either naturally, in the field. Ex situ mycorrhization solutions are considered as less costly, yet efficient alternative to improve the ex vitro survival of micropropagated plants or endangered tree species or for those with economic importance, in vitro propagation is an important conservation tool combined with the acquisition of appropriate mycorrhizal mutualists. 

  1. Mycorrhizal status of several Quercus species in Romania (Quercus cerris, Q. frainetto, Q. robur and the optimization perspective of growth conditions for in vitro propagated plants transplanted in the field

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-02-01

    Full Text Available There is an increasing interest for important tree species conservation in the context of climate change, anthropogenic pressure and invasion of alien tree species. A key factor in the survival of trees is represented by the mycorrhizal association. The success of micropropagated trees also depends on the acquisition of mycorrhizal mutualists. Ectomycorrhizal roots samples from several Quercus species (Q. cerris, Q. frainetto, Q. robur were examined for mycorrhizal morphotypes’ characterization. The samples were collected during the vegetation season from stands located in Southern and North-Western Romania. 30 morphotypes of active mycorrhizaewere identified with Cenococcum geophilum Fr. (Ascomycota asdominating morphotype. Previous studies on somatic embryogenesis inQ. robur and Q. frainetto demonstrated the utility of in vitro techniques in obtaining plants from these recalcitrant seed producing species, considered at risk in various areas of the country, due to increasingly stressful conditions. The success rate of the acclimatization process depends on the mycorrhization performed either artificially, in the laboratory, either naturally, in the field. Ex situ mycorrhization solutions are considered as less costly, yet efficient alternative to improve the ex vitro survival ofmicropropagated plants or endangered tree species or for those with economic importance, in vitro propagation is an important conservation tool combined with the acquisition of appropriate mycorrhizal mutualists.

  2. Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from <em>Gymnosperma> <em>glutinosum> Leaves

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    Cristina Rodríguez-Padilla

    2012-09-01

    Full Text Available Bioassay-guided fractionation of hexane extracts of<em> Gymnosperma glutinosumem> (Asteraceae leaves, collected in North Mexico, afforded the known compounds hentriacontane (1 and (+-13<em>S>,14<em>R>,15-trihydroxy-<em>ent>-labd-7-ene (2, as well as the new <em>ent>-labdane diterpene (−-13<em>S>,14<em>R>,15-trihydroxy-7-oxo-<em>ent>-labd-8(9-ene (3. In addition, D-glycero-D-galactoheptitol (4 was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the <em>in vitroem> L5178Y-R lymphoma murine model. Hentriacontane (1 and the new <em>ent>-labdane 3 showed weak cytotoxicity, whereas the <em>ent>-labdane 2 showed significant (<em>p> < 0.05 and concentration dependent cytotoxicity (up to 78% against L5178Y-R cells at concentrations ranging from 7.8 to 250 µg/mL.

  3. Holocene variability in the range distribution and abundance of Pinus, Picea abies, and Quercus in Romania; implications for their current status

    Science.gov (United States)

    Feurdean, Angelica; Tanţău, Ioan; Fărcaş, Sorina

    2011-10-01

    This paper examines fourteen fossil pollen datasets from Romania. It aims to investigate the temporal and spatial variability in the range distribution and abundance of three forest taxa, Pinus, Picea abies, and Quercus, during the Holocene. This is essential for understanding their current status in the forests of Eastern Europe, the conditions under which they arose, and the timing and processes responsible for their variability. Results from this synthesis do not indicate any apparent time lag in the establishment of Pinus diploxylon type ( Pinus sylvestris and Pinus mugo), Pinus cembra, P. abies, and Quercus across Romania within the limits of the dating resolution. However, the onset of the mass expansion of P. abies was not uniform, spreading earlier from sites in the western and north-western Carpathians (11,000-10,500 yr BP) than in the east (10,000 yr BP). We found that sites from the western, north-western, and northern Carpathians contained higher abundances of P. abies, whilst Quercus was in higher abundances in sites from the east, but there was no regional distinctiveness in the abundance of Pinus across the study area. However, P. diploxylon type was found in much higher abundance than P. cembra. Additionally, results indicate a greater proportion of Pinus (mainly P. diplxylon type) at high elevations, P. abies at mid to high elevations, and Quercus at low elevations (Pinus in the early Holocene boreal forest is likely the legacy of its local glacial refugia, fast life history strategies, high stress tolerance, and large habitat availability. In contrast, Pinus exhibited poor competitive abilities and was quickly replaced with P. abies and temperate deciduous taxa after 10,500 yr BP. P. abies has persisted in large abundances at higher elevations (above 1000 m) until the present day, as a result of good competitive abilities, and resilience to climate change and disturbance. The long-term dominance of P. abies appears to have been spatially

  4. em arquitetura e urbanismo

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    Ana Maria Sala Minucci Martins

    2006-01-01

    Full Text Available Está sendo desenvolvido projeto de pesquisa denominado Geometria Fractal e suas Aplicações em Arquitetura e Urbanismo, com o fito de estudar e desenvolver ferramentas analíticas e propositivas para serem aplicadas em arquitetura e urbanismo, com base em conceitos provenientes da geometria fractal.

  5. Antimicrobial Activity of Geranium Oil against Clinical Strains<em> em>of <em>Staphylococcus aureusem>

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    Monika Sienkiewicz

    2012-08-01

    Full Text Available The aim of this work was to investigate the antibacterial properties of geranium oil obtained from <em>Pelargonium graveolensem> Ait. (family <em>Geraniaceae>, against one standard <em>S. aureus em>strain ATCC 433000 and seventy clinical <em>S. aureusem> strains. The agar dilution method was used for assessment of bacterial growth inhibition at various concentrations of geranium oil. Susceptibility testing of the clinical strains to antibiotics was carried out using the disk-diffusion and E-test methods. The results of our experiment showed that the oil from <em>P. graveolensem> has strong activity against all of the clinical <em>S. aureusem> isolates—including multidrug resistant strains, MRSA strains and MLSB-positive strains—exhibiting MIC values of 0.25–2.50 μL/mL.

  6. Effect of flooding on C metabolism of flood-tolerant (Quercus robur) and non-tolerant (Fagus sylvatica) tree species.

    Science.gov (United States)

    Ferner, Eleni; Rennenberg, Heinz; Kreuzwieser, Jürgen

    2012-02-01

    Flooding is assumed to cause an energy crisis in plants because-due to a lack of O(2)-mitochondrial respiration is replaced by alcoholic fermentation which yields considerably less energy equivalents. In the present study, the effect of flooding on the carbon metabolism of flooding-tolerant pedunculate oak (Quercus robur L.) and flooding-sensitive European beech (Fagus sylvatica L.) seedlings was characterized. Whereas soluble carbohydrate concentrations dropped in roots of F. sylvatica, they were constant in Q. robur during flooding. At the same time, root alcohol dehydrogenase activities were decreased in beech but not in oak, suggesting substrate limitation of alcoholic fermentation in beech roots. Surprisingly, leaf and phloem sap sugar concentrations increased in both species but to a much higher degree in beech. This finding suggests that the phloem unloading process in flooding-sensitive beech was strongly impaired. It is assumed that root-derived ethanol is transported to the leaves via the transpiration stream. This mechanism is considered an adaptation to flooding because it helps avoid the accumulation of toxic ethanol in the roots and supports the whole plant's carbon metabolism by channelling ethanol into the oxidative metabolism of the leaves. A labelling experiment demonstrated that in the leaves of flooded trees, ethanol metabolism does not differ between flooded beech and oak, indicating that processes in the roots are crucial for the trees' flooding tolerance.

  7. Sweets for the foe - effects of nonstructural carbohydrates on the susceptibility of Quercus robur against Phytophthora quercina.

    Science.gov (United States)

    Angay, Oguzhan; Fleischmann, Frank; Recht, Sabine; Herrmann, Sylvie; Matyssek, Rainer; Oßwald, Wolfgang; Buscot, François; Grams, Thorsten E E

    2014-09-01

    The root-rot pathogen Phytophthora quercina is a key determinant of oak decline in Europe. The susceptibility of pedunculate oak (Quercus robur) to this pathogen has been hypothesized to depend on the carbon availability in roots as an essential resource for defense. Microcuttings of Q. robur undergo an alternating rhythm of root and shoot growth. Inoculation of mycorrhizal (Piloderma croceum) and nonmycorrhizal oak roots with P. quercina was performed during both growth phases, that is, root flush (RF) and shoot flush (SF). Photosynthetic and morphological responses as well as concentrations of nonstructural carbohydrates (NSC) were analyzed. Infection success was quantified by the presence of pathogen DNA in roots. Concentrations of NSC in roots depended on the alternating root/shoot growth rhythm, being high and low during RF and SF, respectively. Infection success was high during RF and low during SF, resulting in a significantly positive correlation between pathogen DNA and NSC concentration in roots, contrary to the hypothesis. The alternating growth of roots and shoots plays a crucial role for the susceptibility of lateral roots to the pathogen. NSC availability in oak roots has to be considered as a benchmark for susceptibility rather than resistance against P. quercina.

  8. Atmospheric pollutants in peri-urban forests of Quercus ilex: evidence of pollution abatement and threats for vegetation.

    Science.gov (United States)

    García-Gómez, Héctor; Aguillaume, Laura; Izquieta-Rojano, Sheila; Valiño, Fernando; Àvila, Anna; Elustondo, David; Santamaría, Jesús M; Alastuey, Andrés; Calvete-Sogo, Héctor; González-Fernández, Ignacio; Alonso, Rocío

    2016-04-01

    Peri-urban vegetation is generally accepted as a significant remover of atmospheric pollutants, but it could also be threatened by these compounds, with origin in both urban and non-urban areas. To characterize the seasonal and geographical variation of pollutant concentrations and to improve the empirical understanding of the influence of Mediterranean broadleaf evergreen forests on air quality, four forests of Quercus ilex (three peri-urban and one remote) were monitored in different areas in Spain. Concentrations of nitrogen dioxide (NO2), ammonia (NH3), nitric acid (HNO3) and ozone (O3) were measured during 2 years in open areas and inside the forests and aerosols (PM10) were monitored in open areas during 1 year. Ozone was the only air pollutant expected to have direct phytotoxic effects on vegetation according to current thresholds for the protection of vegetation. The concentrations of N compounds were not high enough to directly affect vegetation but could be contributing through atmospheric N deposition to the eutrophization of these ecosystems. Peri-urban forests of Q. ilex showed a significant below-canopy reduction of gaseous concentrations (particularly NH3, with a mean reduction of 29-38%), which indicated the feasibility of these forests to provide an ecosystem service of air quality improvement. Well-designed monitoring programs are needed to further investigate air quality improvement by peri-urban ecosystems while assessing the threat that air pollution can pose to vegetation.

  9. 麻栎种子萌发的抑制机制%Inhibitory Mechanism of Seed Germination of Quercus acutissima

    Institute of Scientific and Technical Information of China (English)

    刘艳; 李庆梅; 刘广全; 刘勇; 侯龙鱼; 李国雷

    2012-01-01

    Over the last three decades, decline of oak (Quercus acutissima) natural regeneration has drawn wide attention. Exploration of the causes and development of the seedling technology, which promotes quick and uniform germination of oak seeds, arise interesting of forest researchers. In this paper, the seed cold storage and mechanical damage treatments were studied on germination of Q. acutissima. Methanol extracts of embryo, cotyledon and pericarp of oak seeds were used to investigate existence of inhibitory substance by testing germination of Brassica campestris seeds that were cultivated in Sanyo growth cabinet. The results showed that: (1) removing scar, pericarp, or cutting off a small piece of basal cotyledon increased the rooting rate and percentage, however, cutting off more than 1 /2 cotyledon had negative effects; (2) the seed cold storage accelerated the germination; ( 3 ) Germination rates of B. campestris seeds treated by methanol extracts from embryo of Q. acutissima seeds were significantly lower than control, and inhibitors from embryo, cotyledon and pericarp played a negative role in growth of root and shoot of B. campestris seedlings, indicating that the inhibitors of oak seeds might mainly restrict growth of root and shoot themselves, and be responsible for germinating irregularly. The results have guiding significance for directly seeding afforestation and seedling of Q. acutissima.

  10. [Spatial pattern analysis and associations of Quercus aquifolioides population at different growth stages in Southeast Tibet, China].

    Science.gov (United States)

    Shen, Zhi-qiang; Hua, Min; Dan, Qu; Lu, Jie; Fang, Jiang-ping

    2016-02-01

    This article analyzed the spatial pattern and its correlation of Quercus aquifolioides, Southeast Tibet at different growing stages by using Ripley' s L function in the method of point pattern, analysis. The results showed the diameter structure of Q. aquifolioides population in Southeast Tibet followed a 'single peak' shape and the saplings and medium trees predominated in number in the whole population. The population had a high regeneration rate and was of increase type. In the growth process of Q. aquifolioides from saplings to large trees, saplings and medium trees showed aggregation distribution at.small scale, while large trees showed basically random distribution at whole scale. There was significant correlation between saplings with medium or large trees at small scale, however, there was no correlation between medium and large trees. In the growth process of Q. aquifolioides population from saplings, medium trees to large trees, its spatial pattern developed from aggregative distribution to random distribution. The natural regeneration of Q. aquifolioides population was affected not only by interspecific competition, but also by intraspecific competition. In the similar natural environment, the most important factors affecting the spatial pattern of Q. aquifoioides population were its own biological and ecological characteristics.

  11. Leaf N and P stoichiometry in relation to leaf shape and plant size for Quercus acutissima provenances across China.

    Science.gov (United States)

    Zhang, Hui; Yang, Xiuqing; Wang, Jingyuan; Wang, G Geoff; Yu, Mukui; Wu, Tonggui

    2017-04-10

    Plant stoichiometry in relation to the structure and function of biological systems has been investigated at multiple scales. However, few studies have focused on the roles of stoichiometry for a given species. In this study, we determined leaf N and P stoichiometry, leaf shape and plant size in three Quercus acutissima common gardens with different climatic and site conditions. In the three common gardens, leaf N and P stoichiometry was significantly correlated with leaf shape and plant size, suggesting that leaf N and P stoichiometry affects the morphological performance of the leaves and stem. The scaling slopes of the relationships between leaf N and P stoichiometry and leaf shape ranged from |0.12| to |1.00|, while the slopes of the relationships between leaf N and P stoichiometry and plant size ranged from |0.95| to |2.66|. These results suggest that non-functional tissues (stem) are more susceptible to leaf nutrition than functional tissues (leaves), and leaf stoichiometry is more important in the construction of non-functional tissues (stem). Between the northernmost and southernmost common gardens, leaf N and leaf width (W), N:P and stem height (H), and N:P and stem diameter (D) showed significant covariations, which indicates that leaf N and W, N:P and plant size exhibit similar plastic responses to environmental change.

  12. Comparative Drought Responses of Quercus ilex L. and Pinus sylvestris L. in a Montane Forest Undergoing a Vegetation Shift

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    David Aguadé

    2015-07-01

    Full Text Available Different functional and structural strategies to cope with water shortage exist both within and across plant communities. The current trend towards increasing drought in many regions could drive some species to their physiological limits of drought tolerance, potentially leading to mortality episodes and vegetation shifts. In this paper, we study the drought responses of Quercus ilex and Pinus sylvestris in a montane Mediterranean forest where the former species is replacing the latter in association with recent episodes of drought-induced mortality. Our aim was to compare the physiological responses to variations in soil water content (SWC and vapor pressure deficit (VPD of the two species when living together in a mixed stand or separately in pure stands, where the canopies of both species are completely exposed to high radiation and VPD. P. sylvestris showed typical isohydric behavior, with greater losses of stomatal conductance with declining SWC and greater reductions of stored non-structural carbohydrates during drought, consistent with carbon starvation being an important factor in the mortality of this species. On the other hand, Q. ilex trees showed a more anisohydric behavior, experiencing more negative water potentials and higher levels of xylem embolism under extreme drought, presumably putting them at higher risk of hydraulic failure. In addition, our results show relatively small changes in the physiological responses of Q. ilex in mixed vs. pure stands, suggesting that the current replacement of P. sylvestris by Q. ilex will continue.

  13. ADSORPTION CHARACTERIZATION OF CO(II IONS ONTO CHEMICALLY TREATED QUERCUS COCCIFERA SHELL: EQUILIBRIUM, KINETIC AND THERMODYNAMIC STUDIES

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    M. Hamdi Karaoglu

    2011-04-01

    Full Text Available Quercus coccifera shell (QCS, a relatively abundant and inexpensive material, is currently being investigated as an adsorbent to remove cobalt(II from water. Before the adsorption experiments, QCS was subjected to chemical treatment to provide maximum surface area. Then, the kinetics and adsorption mechanism of Co(II ions on QCS were studied using different parameters such as adsorbent dosage, initial concentration, temperature, contact time, and solution pH. The loaded metals could be desorbed effectively with dilute hydrochloric acid, nitric acid, and 0.1 M EDTA. The Langmuir and Freundlich models were used to describe the uptake of cobalt on QCS. The equilibrium adsorption data were better fitted to Langmuir adsorption isotherm model. The maximum adsorption capacity (qm of QCS for Co(II was 33 mg g-1. Various kinetic models were used to describe the adsorption process. The adsorption followed pseudo second-order kinetic model. The intraparticle diffusion was found to be the rate-limiting step in the adsorption process. The diffusion coefficients were calculated and found to be in the range of 3.11×10−6 to 168.78×10−6 cm2s-1. The negative DH* value indicated exothermic nature of the adsorption.

  14. Effect of elevated atmospheric CO2 concentration on growth and leaf litter decomposition of Quercus acutissima and Fraxinus rhynchophylla.

    Science.gov (United States)

    Cha, Sangsub; Chae, Hee-Myung; Lee, Sang-Hoon; Shim, Jae-Kuk

    2017-01-01

    The atmospheric carbon dioxide (CO2) level is expected to increase substantially, which may change the global climate and carbon dynamics in ecosystems. We examined the effects of an elevated atmospheric CO2 level on the growth of Quercus acutissima and Fraxinus rhynchophylla seedlings. We investigated changes in the chemical composition of leaf litter, as well as litter decomposition. Q. acutissima and F. rhynchophylla did not show differences in dry weight between ambient CO2 and enriched CO2 treatments, but they exhibited different patterns of carbon allocation, namely, lower shoot/root ratio (S/R) and decreased specific leaf area (SLA) under CO2-enriched conditions. The elevated CO2 concentration significantly reduced the nitrogen concentration in leaf litter while increasing lignin concentrations and carbon/nitrogen (C/N) and lignin/N ratios. The microbial biomass associated with decomposing Q. acutissima leaf litter was suppressed in CO2 enrichment chambers, while that of F. rhynchophylla was not. The leaf litter of Q. acutissima from the CO2-enriched chambers, in contrast with F. rhynchophylla, contained much lower nutrient concentrations than that of the litter in the ambient air chambers. Consequently, poorer litter quality suppressed decomposition.

  15. Responses of nutrients and mobile carbohydrates in Quercus variabilis seedlings to environmental variations using in situ and ex situ experiments.

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    Jing-Pin Lei

    Full Text Available Forest tree species distributed across a wide range of geographical areas are subjected to differential climatic and edaphic conditions and long-term selection, leading to genotypes with morphological and physiological adaptation to the local environment. To test the ability of species to cope with changing environmental conditions, we studied the ecophysiological features of Quercus variabilis using seedlings grown in geographically widely isolated populations (Exp. I, in situ and in a common garden (Exp. II, ex situ using seedlings originating from those populations. We found that Q. variabilis plants grown in different locations along a south-north gradient had different levels of nutrients (N, P, K and carbon-physiological performance (photosynthesis, non-structural carbohydrates, such as soluble sugars and starch, and that these physiological differences were not correlated with local soil properties. These geographic variations of plant physiology disappeared when plants from different locations were grown in the same environment. Our results indicate that the physiological performance of Q. variabilis plants is mainly determined by the climatic variations across latitude rather than by their soils or by genetic differentiation. The adaptive ability of Q. variabilis found in the present study suggests that this species has the potential to cope, at least to some extent, with changing environmental conditions.

  16. Root vitality of Fagus sylvatica L., Quercus petraea Liebl. and Acer pseudoplatanus L. in mature mixed forest stand

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    Grygoruk Dorota

    2016-06-01

    Full Text Available The main task of the present study was to investigate the root vitality of common beech Fagus sylvatica L., sessile oak Quercus petraea Liebl. and sycamore maple Acer pseudoplatanus L. in the optimal g rowth conditions in south-western Poland. The study was carried out in 130-year-old mixed stand located within natural range of studied tree species. The density of roots (g/100 cm3 of soil and biomass of fine roots (g/m2 in topsoil layers (0-5 cm, 5-15 cm were determined in the tree biogroups of the same species. The mean total root density ranged from 0.248 to 0.417 g/100 cm3 in the 0-5 cm soil layer, and it decreased in the deeper soil layer (5-15 cm. There were found no statistically significant differences of total root densities between tree biogroups in topsoil layers. Diversity of fine root biomass was comparable in the tree biogroups (H’ = 1.5, but common beech showed more intensive growth of fine roots in the topsoil 0-15 cm when compared to sessile oak and sycamore maple. The results of the study point out the stability of the multi-species structure of the mixed stand studied, and consequently - the ability of beech, sessile oak and sycamore maple trees to coexist in the mixed stands - in the area of natural range of these species.

  17. The Microstructure of Cork from Quercus variabilis%栓皮栎软木的微观构造

    Institute of Scientific and Technical Information of China (English)

    雷亚芳; 刘艳贞; 周伟; 赵泾峰

    2009-01-01

    栓皮栎(Quercus variabilis)或栓皮槠(p.suber)树皮部分的木栓层通常称为“软木”,英文为cork或者phellogen,与通常所说的针叶材软木(softwood)不同。软木独特的细胞构造及其化学成分使其具有质轻、弹性好、隔热、隔音、隔水、防潮、阻燃、柔软、耐磨等优良特性,素有“软黄金”之称(郑志峰,2005)。软木的应用已经有上千年的历史,软木首先应用于瓶塞行业(赵戈等,2004),工业上大规模生产始于1780年。

  18. Age trends and within-site effects in wood density and radial growth in Quercus faginea mature trees

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    Vicelina B. Sousa

    2016-04-01

    Full Text Available Aim of the study: This paper aims to valorize the wood of Quercus faginea Lam. for high quality end uses (e.g. furniture by studying growth and quality properties using mature trees. Age trends in tree-ring width and wood density are shown and the main factors responsible for variations in tree-ring width and wood density within and between trees are investigated. Area of study: The study site is in the center of Portugal within the natural species distribution area.Material and methods: Radial samples from ten mature trees were collected at 6 heights (from base to 9.7 m and prepared for X-ray microdensity.Main results: Wood density showed high values, ranging from 0.868 g/cm3 to 0.957 g/cm3. Wood density decreased from pith to bark and with stem height. Cambial age showed a linear relationship with wood density and most of the variation in wood is explained by age. Intra-ring and axial within-tree homogeneity was good.Research highlights: Mature trees of Q. faginea showed high wood density and a high potential for high quality end uses, comparable to other oaks. Wood density is influenced by cambial age and tree-ring width. Wood quality may be improved by tree growth rates adjustment e.g. through an adequate tree stand density (e.g. thinning operations. 

  19. Foliage maturity of Quercus ilex affects the larval development of a Croatian coastal population of Lymantria dispar (Lepidoptera: Erebidae

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    Lukić Ivan

    2017-02-01

    Full Text Available Gypsy moth (Lymantria dispar is one of the most important forest pests in the world. Numerous previous studies focused only on different host tree species, but small number of them on foliage age. Since recent genetic analyses showed that there are significant differences between Croatian continental and coastal population we investigated coastal population since there was no previous research. For this research juvenile and mature foliage of Holm oak (Quercus ilex was used. Larval development was investigated in two laboratory experiments. One experiment involved rearing trials consisting of 50 individual larvae per treatment while a parallel experiment investigated gregarious feeding conditions using 120 larvae in a rearing treatment. Larval mortality was lower and development time shorter for individuals reared on juvenile foliage. High pupation success in both the individual and group rearing experiment for larvae reared on juvenile foliage was also observed. To conclude, our results showed high mortality, poor larval development and low pupation success in larvae reared on mature foliage. This research is significant because in the aspect of ongoing climate changes there is a possibility that gypsy moth will move to the north and shift its distribution by expanding into new climatic area.

  20. Genome scanning for interspecific differentiation between two closely related oak species [Quercus robur L. and Q. petraea (Matt.) Liebl.].

    Science.gov (United States)

    Scotti-Saintagne, Caroline; Mariette, Stéphanie; Porth, Ilga; Goicoechea, Pablo G; Barreneche, Teresa; Bodénès, Catherine; Burg, Kornel; Kremer, Antoine

    2004-11-01

    Interspecific differentiation values (G(ST)) between two closely related oak species (Quercus petraea and Q. robur) were compiled across different studies with the aim to explore the distribution of differentiation at the genome level. The study was based on a total set of 389 markers (isozymes, AFLPs, SCARs, microsatellites, and SNPs) for which allelic frequencies were estimated in pairs of populations sampled throughout the sympatric distribution of the two species. The overall distribution of G(ST) values followed an L-shaped curve with most markers exhibiting low species differentiation (G(ST) 10% levels. Twelve percent of the loci exhibited significant G(ST) deviations to neutral expectations, suggesting that selection contributed to species divergence. Coding regions expressed higher differentiation than noncoding regions. Among the 389 markers, 158 could be mapped on the 12 linkage groups of the existing Q. robur genetic map. Outlier loci with large G(ST) values were distributed over 9 linkage groups. One cluster of three outlier loci was found within 0.51 cM; but significant autocorrelation of G(ST) was observed at distances <2 cM. The size and distribution of genomic regions involved in species divergence are discussed in reference to hitchhiking effects and disruptive selection.

  1. Ectomycorrhizal diversity and community structure in stands of Quercus oleoides in the seasonally dry tropical forests of Costa Rica

    Science.gov (United States)

    Desai, Nikhilesh S.; Wilson, Andrew W.; Powers, Jennifer S.; Mueller, Gregory M.; Egerton-Warburton, Louise M.

    2016-12-01

    Most conservation efforts in seasonally dry tropical forests have overlooked less obvious targets for conservation, such as mycorrhizal fungi, that are critical to plant growth and ecosystem structure. We documented the diversity of ectomycorrhizal (EMF) and arbuscular mycorrhizal (AMF) fungal communities in Quercus oleoides (Fagaceae) in Guanacaste province, Costa Rica. Soil cores and sporocarps were collected from regenerating Q. oleoides plots differing in stand age (early vs late regeneration) during the wet season. Sequencing of the nuclear ribosomal ITS region in EMF root tips and sporocarps identified 37 taxa in the Basidiomycota; EMF Ascomycota were uncommon. The EMF community was dominated by one species (Thelephora sp. 1; 70% of soil cores), more than half of all EMF species were found only once in an individual soil core, and there were few conspecific taxa. Most EMF taxa were also restricted to either Early or Late plots. Levels of EMF species richness and diversity, and AMF root colonization were similar between plots. Our results highlight the need for comprehensive spatiotemporal samplings of EMF communities in Q. oleoides to identify and prioritize rare EMF for conservation, and document their genetic and functional diversity.

  2. Responses of nutrients and mobile carbohydrates in Quercus variabilis seedlings to environmental variations using in situ and ex situ experiments.

    Science.gov (United States)

    Lei, Jing-Pin; Xiao, Wenfa; Liu, Jian-Feng; Xiong, Dingpeng; Wang, Pengcheng; Pan, Lei; Jiang, Yong; Li, Mai-He

    2013-01-01

    Forest tree species distributed across a wide range of geographical areas are subjected to differential climatic and edaphic conditions and long-term selection, leading to genotypes with morphological and physiological adaptation to the local environment. To test the ability of species to cope with changing environmental conditions, we studied the ecophysiological features of Quercus variabilis using seedlings grown in geographically widely isolated populations (Exp. I, in situ) and in a common garden (Exp. II, ex situ) using seedlings originating from those populations. We found that Q. variabilis plants grown in different locations along a south-north gradient had different levels of nutrients (N, P, K) and carbon-physiological performance (photosynthesis, non-structural carbohydrates, such as soluble sugars and starch), and that these physiological differences were not correlated with local soil properties. These geographic variations of plant physiology disappeared when plants from different locations were grown in the same environment. Our results indicate that the physiological performance of Q. variabilis plants is mainly determined by the climatic variations across latitude rather than by their soils or by genetic differentiation. The adaptive ability of Q. variabilis found in the present study suggests that this species has the potential to cope, at least to some extent, with changing environmental conditions.

  3. Contrasting Hydraulic Strategies during Dry Soil Conditions in Quercus rubra and Acer rubrum in a Sandy Site in Michigan

    Directory of Open Access Journals (Sweden)

    Julia E. Thomsen

    2013-12-01

    Full Text Available Correlation analyses were carried out for the dynamics of leaf water potential in two broad-leaf deciduous tree species in a sandy site under a range of air vapor pressure deficits and a relatively dry range of soil conditions. During nights when the soil is dry, the diffuse-porous, isohydric and shallow-rooted Acer rubrum does not recharge its xylem and leaf water storage to the same capacity that is observed during nights when the soil is moist. The ring-porous, deep-rooted Quercus rubra displays a more anisohydric behavior and appears to be capable of recharging to capacity at night-time even when soil moisture at the top 1 m is near wilting point, probably by accessing deeper soil layers than A. rubrum. Compared to A. rubrum, Q. rubra displays only a minimal level of down-regulation of stomatal conductance, which leads to a reduction of leaf water potential during times when vapor pressure deficit is high and soil moisture is limiting. We determine that the two species, despite typically being categorized by ecosystem models under the same plant functional type—mid-successional, temperate broadleaf—display different hydraulic strategies. These differences may lead to large differences between the species in water relations, transpiration and productivity under different precipitation and humidity regimes.

  4. Paisang ( Quercus griffithii): A Keystone Tree Species in Sustainable Agroecosystem Management and Livelihoods in Arunachal Pradesh, India

    Science.gov (United States)

    Singh, Ranjay K.; Singh, Anshuman; Garnett, Stephen T.; Zander, Kerstin K.; Lobsang; Tsering, Darge

    2015-01-01

    In a study of the traditional livelihoods of 12 Monpa and Brokpa villages in Arunachal Pradesh, India using social-ecological and participatory rural appraisal techniques, we found that the forest tree species paisang ( Quercus griffithii, a species of oak) is vital to agroecosystem sustainability. Paisang trees are conserved both by individuals and through community governance, because their leaves play a crucial role in sustaining 11 traditional cropping systems of the Monpa peoples. An Indigenous institution, Chhopa, regulates access to paisang leaves, ensuring that the relationship between paisang and traditional field crop species within Monpa agroecosystems is sustainable. The Monpa farmers also exchange leaves and agricultural products for yak-based foods produced by the transhumant Brokpa, who are primarily yak herders. Yak herds also graze in paisang groves during winter. These practices have enabled the conservation of about 33 landraces, yak breeds, and a number of wild plants. Paisang thus emerged as a culturally important keystone species in the cultures and livelihoods of both Monpa and Brokpa. Ecological and conservation knowledge and ethics about paisang vary with gender, social systems, and altitudes. Labor shortages, however, have already caused some changes to the ways in which paisang leaves are used and yak grazing patterns are also changing in the face of changes in attitude among local landowners. Given new competing interests, incentives schemes are now needed to conserve the ecologically sustainable traditional livelihoods.

  5. Association between radionuclides ((210)Po and (210)Pb) and antioxidant enzymes in oak (Quercus coccifera) and mastic tree (Pistacia lentiscus).

    Science.gov (United States)

    Uğur Görgün, A; Aslan, E; Kül, M; İlhan, S; Dimlioğlu, G; Bor, M; Özdemir, F

    2016-08-27

    The activity levels of naturally occurring radionuclides Polonium-210 and lead-210 in different subjects including plant species have direct or indirect impact on human beings. High levels of ionising radiation cause oxidative stress and the interaction between antioxidative defense and radionuclides is not well established in plant systems. In this study, we aimed to understand the impact of oxidative stress caused by (210)Po and (210)Pb in two Mediterranean plants; Quercus coccifera and Pistacia lentiscus. We analysed the constitutive and seasonal levels of (210)Po, (210)Pb, lipid peroxidation levels, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the field-collected samples. The highest activity concentrations of (210)Po and (210)Pb were detected in both plants in summer and Q. coccifera had higher levels than that of P. lentiscus. SOD and APX activity trends were different between oak and mastic; as compared to P. lentiscus, Q. coccifera efficiently used the two major components of antioxidative defense. Lipid peroxidation levels were low in both plants in all seasons except that of spring which were in good agreement with high antioxidant enzyme activities. In conclusion, we found that high (210)Po and (210)Pb activity concentrations in oak and mastic did not interfere with their growth and life cycles. The ability of both plants for survival and adaptation to Mediterranean environmental constraints provided an additional advantage for coping radionuclide induced oxidative stress as well.

  6. Increased Drying Rate Lowers the Critical Water Content for Survival in Embryonic Axes of English Oak (Quercus robur L.) Seeds

    Institute of Scientific and Technical Information of China (English)

    Tobias M. Ntuli; William E. Finch-Savage; Patricia Berjak; Norman W. Pammenter

    2011-01-01

    The potential to cryopreserve embryonic axes of desiccation-sensitive (recalcitrant) seeds is limited by damage during the desiccation necessary for low temperature survival, but the basis of this injury and how to reduce it is not well understood. The effects of drying rate on the viability, respiratory metabolism and free radical-mediated processes were therefore investigated during dehydration of Quercus robur L. embryonic axes. Viability, assessed by evidence of germination and tetrazolium staining, showed a sharp decline at 0.27 and 0.8 g/g during rapid (<12 h) or slow (3 d) dehydration, respectively. Rapid dehydration therefore lowered the critical water content for survival. At any given water content rapid dehydration was associated with higher activities of the free radical processing enzymes, superoxide dismutase, catalase and glutathione reductase and lower levels of hydroperoxide and membrane damage. Rapid dehydration was also associated with lower malate dehydrogenase activity, and a reduced decline in phosphofructokinase activity and in levels of the oxidized form of nicotinamide dinucleotide. Ageing may have contributed to increased damage during slow dehydration, since viability declined even in hydrated storage after 3 d. The results presented are consistent with rapid dehydration reducing the accumulation of damage resulting from desiccation induced aqueous-based deleterious reactions.

  7. Micromammals (Insectivora; Rodentia of "Valle dell'Inferno" (Rome / Micromammiferi (Insectivora; Rodentia della Valle dell'Inferno (Roma

    Directory of Open Access Journals (Sweden)

    Roberto Federici

    1986-12-01

    Full Text Available Abstract A research on micromammals in the area of "Valle dell'Inferno" (in the north-west of Rome was carried out. The study was based on a previous phytosociological survey which describes a <em>Quercus suber> population in the valley (a once larger residua1 of a roman cork-tree wood which is now included in the town. Specimens from Rodents (<em>Apodemus sylvaticusem>, <em>Mus domesticusem>, <em>Rattus rattusem>, <em>R. norvegicusem>, <em>Pitymys saviiem> and Insectivores (<em>Crocidura suaveolensem>, <em>Erinaceus europaeusem> were captured by live traps. Most of Insectivores specimens are represented by <em>C. suaveolensem>. Generally <em>C. suaveolensem> lives in sympatry with <em>C. leucodonem> but no specimens of the latter were found in this area. Three different kinds of landscape are present in the "Inferno" valley, namely, the wood, the meadow, and the bottom valley (with high anthropic impact; we have compared these three landscapes with biotic indexes (index of faunistic affinity, index of biocoenotic affinity and index of environmental evaluation. We have also compared through the same indexes, the micromammal fauna of the "Inferno" valley with six other differently polluted localities in Latium, where animals were captured with the same live traps. This area retains its natura1 environment in despite of the high anthropic impact. Riassunto È stato effettuato uno studio sulla micromammalofauna terrestre della Valle dell'Inferno situata a nord-ovest di Roma. Lo studio è basato su una precedente indagine fitosociologica effettuata per la caratterizzazione vegetazionale di una sughereta un tempo molto estesa ed ora racchiusa nell'abitato cittadino. È stato pertanto possibile tracciare, tramite gli indici biotici, una correlazione tra microteriocenosi ed effetti dell'impatto antropico.

  8. EM International. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    It is the intent of EM International to describe the Office of Environmental Restoration and Waste Management`s (EM`s) various roles and responsibilities within the international community. Cooperative agreements and programs, descriptions of projects and technologies, and synopses of visits to international sites are all highlighted in this semiannual journal. Focus on EM programs in this issue is on international collaboration in vitrification projects. Technology highlights covers: in situ sealing for contaminated sites; and remote sensors for toxic pollutants. Section on profiles of countries includes: Arctic contamination by the former Soviet Union, and EM activities with Germany--cooperative arrangements.

  9. Microsatellite Loci in the Gypsophyte <em>Lepidium subulatum em>(Brassicaceae, and Transferability to Other <em>Lepidieae>

    Directory of Open Access Journals (Sweden)

    José Gabriel Segarra-Moragues

    2012-09-01

    Full Text Available Polymorphic microsatellite markers were developed for the Ibero-North African, strict gypsophyte <em>Lepidium subulatumem> to unravel the effects of habitat fragmentation in levels of genetic diversity, genetic structure and gene flow among its populations. Using 454 pyrosequencing 12 microsatellite loci including di- and tri-nucleotide repeats were characterized in <em>L. subulatumem>. They amplified a total of 80 alleles (2–12 alleles per locus in a sample of 35 individuals of <em>L. subulatumem>, showing relatively high levels of genetic diversity, <em>H>O = 0.645, <em>H>E = 0.627. Cross-species transferability of all 12 loci was successful for the Iberian endemics <em>Lepidium cardaminesem>, <em>Lepidium stylatumem>, and the widespread, <em>Lepidium graminifoliumem> and one species each of two related genera, <em>Cardaria drabaem> and <em>Coronopus didymusem>. These microsatellite primers will be useful to investigate genetic diversity, population structure and to address conservation genetics in species of <em>Lepidium>.

  10. New Trifluoromethyl Triazolopyrimidines as Anti-<em>Plasmodium> <em>falciparum> Agents

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    Núbia Boechat

    2012-07-01

    Full Text Available According to the World Health Organization, half of the World’s population, approximately 3.3 billion people, is at risk for developing malaria. Nearly 700,000 deaths each year are associated with the disease. Control of the disease in humans still relies on chemotherapy. Drug resistance is a limiting factor, and the search for new drugs is important. We have designed and synthesized new 2-(trifluoromethyl[1,2,4]triazolo[1,5-<em>a>]pyrimidine derivatives based on bioisosteric replacement of functional groups on the anti-malarial compounds mefloquine and amodiaquine. This approach enabled us to investigate the impact of: (i ring bioisosteric replacement; (ii a CF3 group substituted at the 2-position of the [1,2,4]triazolo[1,5-<em>a>]pyrimidine scaffold and (iii a range of amines as substituents at the 7-position of the of heterocyclic ring; on <em>in vitroem> activity against <em>Plasmodium falciparumem>. According to docking simulations, the synthesized compounds are able to interact with <em>P. falciparumem> dihydroorotate dehydrogenase (<em>Pf>DHODH through strong hydrogen bonds. The presence of a trifluoromethyl group at the 2-position of the [1,2,4]triazolo[1,5-<em>a>]pyrimidine ring led to increased drug activity. Thirteen compounds were found to be active, with IC50 values ranging from 0.023 to 20 µM in the anti-HRP2 and hypoxanthine assays. The selectivity index (SI of the most active derivatives 5, 8, 11 and 16 was found to vary from 1,003 to 18,478.

  11. Screening and Analysis of the Potential Bioactive Components in Rabbit Plasma after Oral Administration of Hot-Water Extracts from Leaves of <em>B>ambusa em>>textilis em>McClure

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    Jia Sun

    2012-07-01

    Full Text Available <em>Bambusa textilisem> McClure is a traditional Chinese medicinal plant belonging to the Bambusoideae subfamily and used to treat chronic fever and infectious diseases. To investigate the bioactive compounds absorbed in the rabbit blood after oral administration of hot-<em>water extractem>>s from em>>the leaves of em>>B. textilisem> McClure, a validated chromatographic fingerprint method was established using LC-Q-TOF-MS. Twenty compounds in bamboo leaves and three potential bioactive compounds in rabbit plasma were detected. Of the twenty detected compounds <em>in vitroem>, fifteen of which were tentatively identified either by comparing the retention time and mass spectrometry data with that of reference compounds or by reviewing the literature. Three potential bioactive compounds, including (<em>E-p>-coumaric acid, (<em>Z-p>-coumaric acid, and apigenin-8-<em>C>-β-D-(2"-<em>O>-α-L-rhamnosyl-gluco-pyranoside, were detected in both <em>the leaves of em>>B. textilis em>McClure and rabbit plasma. Of the three compounds, apigenin-8-<em>C>-β-D-(2"-<em>O>-α-L-rhamnosylglucopyranoside was identified based on its UV, MS, and NMR spectra. This study provides helpful chemical information for further pharmacology and active mechanism research on <em>B. textilisem> McClure.

  12. Genotoxicity of <em>Euphorbia hirtaem>: An <em>Allium cepaem> Assay

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    Kwan Yuet Ping

    2012-06-01

    Full Text Available The potential genotoxic effects of methanolic extracts of <em>Euphorbia hirta em>which is commonly used in traditional medicine to treat a variety of diseased conditions including asthma, coughs, diarrhea and dysentery was investigated using <em>Allium cepaem> assay. The extracts of 125, 250, 500 and 1,000 µg/mL were tested on root meristems of <em>A. cepaem>. Ethylmethanesulfonate was used as positive control and distilled water was used as negative control. The result showed that mitotic index decreased as the concentrations of <em>E. hirtaem> extract increased. A dose-dependent increase of chromosome aberrations was also observed. Abnormalities scored were stickiness, c-mitosis, bridges and vagrant chromosomes. Micronucleated cells were also observed at interphase. Result of this study confirmed that the methanol extracts of <em>E. hirta em>exerted significant genotoxic and mitodepressive effects at 1,000 µg/mL.

  13. <em>In Vitroem> Antioxidant Properties of Flavonoids and Polysaccharides Extract from Tobacco (<em>Nicotiana> em>tabacum> L. Leaves

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    Jing-Lu Wang

    2012-09-01

    Full Text Available In the present study, antioxidant properties of flavonoids and polysaccharides from tobacco (<em>Nicotiana> tabacumem> L. leaves were evaluated in several <em>in vitroem> systems, e.g., scavenging activities on hydroxyl, superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS radicals, and reducing power. Flavonoids showed much better activity than polysaccharides in scavenging activities on free radicals. When compared to the positive control, ascorbic acid, both showed weaker antioxidant potential. However, flavonoids possessed comparable superoxide anion, DPPH and ABTS radical scavenging abilities to ascorbic acid at high concentration (600 μg/mL. Meanwhile, it was found that flavonoids had prominent effects on the reducing power, which was equivalent to ascorbic acid, and was significantly higher than polysaccharides. These results clearly indicate that flavonoids are effective in scavenging free radicals and have the potential to be powerful antioxidants. Thus, tobacco leaves could be considered as a potential source of natural antioxidants for food, pharmaceutical, cosmetics or nutraceutical industries.

  14. A quantitative and molecular examination of Tuber melanosporum mycorrhizae in Quercus ilex seedlings from different suppliers in Spain

    Directory of Open Access Journals (Sweden)

    P. Alvarado

    2013-07-01

    Full Text Available Aim of study: The aim of the work was to determine the degree of mycorrhization of Quercus ilex L. subsp. ballota (Desf. Samp. by the black truffle fungus T. melanosporum Vittad. by quantitative and molecular analyses.Area of study: seedlings inoculated by different Spanish suppliers.Material and methods: The internal transcribed spacers (ITS of mycorrhizae from different plants were amplified by nested PCR involving fluorescently-labelled primers, and the amplicons either directly sized by ARISA or analysed by TRFLP following their digestion with restriction endonucleases. TRFLP analysis distinguished between mycorrhizae of T. melanosporum, T. indicum Cooke & Massee and T. borchii Vittad., as suggested possible by virtual (in silico TRFLP analysis and real TRFLP analysis of the ascomata of these species.Main results: Significant differences between suppliers were detected in terms of the mean number of mycorrhizae established per plant and percentage mycorrhization. These results allowed the following quality standards for 2 year-old plants to be proposed: a good quality: >3000 mycorrhizae/plant, >40% mycorrhization, b medium (acceptable: >3000 mycorrhizae/plant, >30% mycorrhization, c low quality: <3000 mycorrhizae/plant or <30% mycorrhization, always supposing the mycorrhizae counted represent the species of interest as confirmed by the presence of its DNA and the absence of DNA belonging to contaminating species. Finally, a new microsatellite allelic map obtained from the analysis of several T. melanosporum populations across Spain was used to provide a tool capable of determining the geographic origin of the fungi used to inoculate plants.Research highlights: The proposed quality standards can be useful for the evaluation and certification of commercialized Q. ilex plants mycorrhized with T. melanosporum.Keywords: mycorrhiza; certification; truffle; TRFLP; fungi.

  15. A quantitative and molecular examination of Tuber melanosporum mycorrhizal in Quercus ilex seedlings from different suppliers in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Alvaro, P.; Manjon, J. L.

    2013-09-01

    Aim of study: The aim of the work was to determine the degree of mycorrhization of Quercus ilex L. subsp. ballota (Desf.) Samp. by the black truffle fungus T. melanosporum Vittad. by quantitative and molecular analyses. Area of study: seedlings inoculated by different Spanish suppliers. Material and methods: The internal transcribed spacers (ITS) of mycorrhizae from different plants were amplified by nested PCR involving fluorescently-labelled primers, and the amplicons either directly sized by ARISA or analysed by TRFLP following their digestion with restriction endonucleases. TRFLP analysis distinguished between mycorrhizae of T. melanosporum, T. indicum Cooke and Massee and T. borchii Vittad., as suggested possible by virtual (in silico) TRFLP analysis and real TRFLP analysis of the ascomata of these species. Main results: Significant differences between suppliers were detected in terms of the mean number of mycorrhizae established per plant and percentage mycorrhization. These results allowed the following quality standards for 2 yearold plants to be proposed: a) good quality: > 3,000 mycorrhizae/plant, > 40% mycorrhization, b) medium (acceptable): > 3,000 mycorrhizae/plant, > 30% mycorrhization, c) low quality: < 3,000 mycorrhizae/plant or <30% mycorrhization, always supposing the mycorrhizae counted represent the species of interest as confirmed by the presence of its DNA and the absence of DNA belonging to contaminating species. Finally, a new microsatellite allelic map obtained from the analysis of several T. melanosporum populations across Spain was used to provide a tool capable of determining the geographic origin of the fungi used to inoculate plants. Research highlights: The proposed quality standards can be useful for the evaluation and certification of commercialized Q. ilex plants mycorrhized with T. melanosporum. (Author)

  16. Multilevel Nonlinear Mixed-Effect Crown Ratio Models for Individual Trees of Mongolian Oak (Quercus mongolica) in Northeast China.

    Science.gov (United States)

    Fu, Liyong; Zhang, Huiru; Lu, Jun; Zang, Hao; Lou, Minghua; Wang, Guangxing

    2015-01-01

    In this study, an individual tree crown ratio (CR) model was developed with a data set from a total of 3134 Mongolian oak (Quercus mongolica) trees within 112 sample plots allocated in Wangqing Forest Bureau of northeast China. Because of high correlation among the observations taken from the same sampling plots, the random effects at levels of both blocks defined as stands that have different site conditions and plots were taken into account to develop a nested two-level nonlinear mixed-effect model. Various stand and tree characteristics were assessed to explore their contributions to improvement of model prediction. Diameter at breast height, plot dominant tree height and plot dominant tree diameter were found to be significant predictors. Exponential model with plot dominant tree height as a predictor had a stronger ability to account for the heteroskedasticity. When random effects were modeled at block level alone, the correlations among the residuals remained significant. These correlations were successfully reduced when random effects were modeled at both block and plot levels. The random effects from the interaction of blocks and sample plots on tree CR were substantially large. The model that took into account both the block effect and the interaction of blocks and sample plots had higher prediction accuracy than the one with the block effect and population average considered alone. Introducing stand density into the model through dummy variables could further improve its prediction. This implied that the developed method for developing tree CR models of Mongolian oak is promising and can be applied to similar studies for other tree species.

  17. Photosynthetic activity of Fagus sylvatica L. and Quercus petraea (Matt Liebl. in a mixed stand at Maljen mountain

    Directory of Open Access Journals (Sweden)

    Popović Zorica

    2005-01-01

    Full Text Available Estimation of the photosynthetic performance of co-existing tree species with pronounced differences in ecophysiological context (Aranda et al. 1996 Leuschner et al. 2001 could provide insight into their vitality and competitive abilities at a particular site. Gas exchange, composition of photosynthetic pigments, and the water status of beech (Fagus sylvatica L and sessile oak (Quercus petraea (Matt Liebl were studied in the present work. The investigation was performed on Mt. Maljen (Western Serbia, near the town of Mionica at an altitude of 950 m, in an ecotope within the confines of the mountain's beech forest belt. Codominant samplings [three of each species, 30-years old (n=6, 10-12 m high] were selected for the measurements, which were conducted on fully developed leaves from the out­ermost branches and from the innermost canopy. Photosynthetic measurements were performed using an LI-6200 closed photo­synthesis system (LI-Cor. Inc, Lincoln, NE, USA, while irradiance was detected with a selenium cell mounted on the leaf chamber. Parameters of gas exchange are expressed on the basis of leaf area, using the AREAMETER software (Karadžić et al. 1999. Chlorophyll content was spectrophotometrically determined based on light absorption of the solution obtained after extraction with dMSO (Hiscox and Israelstam, 1979. The midday water saturation deficit was determined according to Turner (1981. For data analysis, we used the Statistic for Windows program package. The ANOVA one-way break­down was applied to compare differences within (leaves inside vs. leaves outside the surface of the tree canopy and between species for all investigated parameters at the 0.05 level of significance.

  18. Chronological Sequence of Leaf Phenology, Xylem and Phloem Formation and Sap Flow of Quercus pubescens from Abandoned Karst Grasslands.

    Science.gov (United States)

    Lavrič, Martina; Eler, Klemen; Ferlan, Mitja; Vodnik, Dominik; Gričar, Jožica

    2017-01-01

    Intra-annual variations in leaf development, radial growth, including the phloem part, and sap flow have rarely been studied in deciduous trees from drought-prone environments. In order to understand better the chronological order and temporal course of these processes, we monitored leaf phenology, xylem and phloem formation and sap flow in Quercus pubescens from abandoned karst grasslands in Slovenia during the growing season of 2014. We found that the initial earlywood vessel formation started before bud opening at the beginning of April. Buds started to open in the second half of April and full leaf unfolding occurred by the end of May. LAI values increased correspondingly with leaf development. About 28% of xylem and 22% of phloem annual increment were formed by the time of bud break. Initial earlywood vessels were fully lignified and ready for water transport, indicating that they are essential to provide hydraulic conductivity for axial water flow during leaf development. Sap flow became active and increasing contemporarily with leaf development and LAI values. Similar early spring patterns of xylem sap flow and LAI denoted that water transport in oaks broadly followed canopy leaf area development. In the initial 3 weeks of radial growth, phloem growth preceded that of xylem, indicating its priority over xylem at the beginning of the growing season. This may be related to the fact that after bud break, the developing foliage is a very large sink for carbohydrates but, at the same time, represents a small transpirational area. Whether the interdependence of the chronological sequence of the studied processes is fixed in Q. pubescens needs to be confirmed with more data and several years of analyses, although the 'correct sequence' of processes is essential for synchronized plant performance and response to environmental stress.

  19. Transpiration of montane Pinus sylvestris L. and Quercus pubescens Willd. forest stands measured with sap flow sensors in NE Spain

    Directory of Open Access Journals (Sweden)

    R. Poyatos

    2005-01-01

    Full Text Available Stand transpiration was measured during the 2003 and 2004 growing seasons using heat dissipation sap flow sensors in a Scots pine (Pinus sylvestris L. and a pubescent oak (Quercus pubescens Willd. forests located in a montane area of the Eastern Pyrenees (NE Spain. The first aim of the study was to assess the differences in quantitative estimates of transpiration (Ec and the response to evaporative demand of the two stands. Over the studied period of 2003, characterised by a severe drought episode during the summer, the oak stand (Ec was only 110 mm compared to the 239 mm transpired by the Scots pine stand, although the ratio of transpiration to reference evapotranspiration (Ec/ET0 in the oak stand compares well with the expected values predicted for low leaf area index (LAI oak forests in southern Europe. Scots pine showed a strong reduction in (Ec/ET0 as the drought developed, whereas pubescent oak was less affected by soil moisture deficits in the upper soil. As a second objective, and given the contrasting meteorological conditions between 2003 and 2004 summer periods, the interannual variability of transpiration was studied in the Scots pine plot. Rainfall during the summer months (June-September in 2003 was almost 40% less than in the same interval in 2004. Accordingly, transpiration was also reduced about 25% in 2003. Finally, Scots pine data from 2003 and 2004 was used to calibrate a simple transpiration model using ET0 and soil moisture deficit (SMD as input variables, and implicitly including stomatal responses to high vapour pressure deficits (Dd and soil water status.

  20. Limited Pollen Dispersal Contributes to Population Genetic Structure but Not Local Adaptation in Quercus oleoides Forests of Costa Rica.

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    Nicholas John Deacon

    Full Text Available Quercus oleoides Cham. and Schlect., tropical live oak, is a species of conservation importance in its southern range limit of northwestern Costa Rica. It occurs in high-density stands across a fragmented landscape spanning a contrasting elevation and precipitation gradient. We examined genetic diversity and spatial genetic structure in this geographically isolated and genetically distinct population. We characterized population genetic diversity at 11 nuclear microsatellite loci in 260 individuals from 13 sites. We monitored flowering time at 10 sites, and characterized the local environment in order to compare observed spatial genetic structure to hypotheses of isolation-by-distance and isolation-by-environment. Finally, we quantified pollen dispersal distances and tested for local adaptation through a reciprocal transplant experiment in order to experimentally address these hypotheses.High genetic diversity is maintained in the population and the genetic variation is significantly structured among sampled sites. We identified 5 distinct genetic clusters and average pollen dispersal predominately occurred over short distances. Differences among sites in flowering phenology and environmental factors, however, were not strictly associated with genetic differentiation. Growth and survival of upland and lowland progeny in their native and foreign environments was expected to exhibit evidence of local adaptation due to the more extreme dry season in the lowlands. Seedlings planted in the lowland garden experienced much higher mortality than seedlings in the upland garden, but we did not identify evidence for local adaptation.Overall, this study indicates that the Costa Rican Q. oleoides population has a rich population genetic history. Despite environmental heterogeneity and habitat fragmentation, isolation-by-distance and isolation-by-environment alone do not explain spatial genetic structure. These results add to studies of genetic structure by

  1. Comparison of the soil carbon and nitrogen contents of Quercus cerris and Fraxinus excelsior in the Mersin-Gulnar region

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    Burcu Yesilbudak

    2013-11-01

    Full Text Available Background: Soil samples were taken from a depth of 0-10 cm under the Quercus cerris and Fraxinus excelsior at an altitude of 1300-1500 m from the Kullin site at Gulnar-Mersin and were compared for their pH, CaCO3, nitrogen (N %, and carbon (C % contents. Balanced soils in natural forest ecosystems are known to be very rich in carbon content which increases with latitude and altitude and that the C/N ratio varies greatly between the soils of different plant species. We determined the values of the C/N rates in Q. cerris and F. excelsior soils of the Gulnar Gezende forest for the first time at this altitude. Material and Methods: A pH meter and Scheibler calcimeter were used to determine the soil pH and lime contents respectively. Percentage C was determined using the Anne method and the N% with the Kjeldahl method. Results: There was no difference in the pH values and nitrogen percentage contents between the two soils. Q. cerris soil was found to have medium levels of CaCO3, while the level of CaCO3 in F. excelsior soils was low. The C/N rates and carbon contents were higher in Q. cerris soil than F. excelsior soil (P<0.05. Conclusions: The higher carbon content of Q. cerris soil can be explained by higher amounts of organic matter compared with F. excelsior, which might depend on factors such as microclimate and their specific characteristics.

  2. Variations in Quercus sp. pollen seasons (1996-2011) in Poznań, Poland, in relation to meteorological parameters.

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    Grewling, Lukasz; Jackowiak, Bogdan; Smith, Matt

    2014-01-01

    The aim of this study is to supply detailed information about oak (Quercus sp.) pollen seasons in Poznań, Poland, based on a 16-year aerobiological data series (1996-2011). The pollen data were collected using a volumetric spore trap of the Hirst design located in Poznań city center. The limits of the pollen seasons were calculated using the 95 % method. The influence of meteorological parameters on temporal variations in airborne pollen was examined using correlation analysis. Start and end dates of oak pollen seasons in Poznań varied markedly from year-to-year (14 and 17 days, respectively). Most of the pollen grains (around 75 % of the seasonal pollen index) were recorded within the first 2 weeks of the pollen season. The tenfold variation was observed between the least and the most intensive pollen seasons. These fluctuations were significantly related to the variation in the sum of rain during the period second fortnight of March to first fortnight of April the year before pollination (r = 0.799; p < 0.001). During the analyzing period, a significant advance in oak pollen season start dates was observed (-0.55 day/year; p = 0.021), which was linked with an increase in the mean temperature during the second half of March and first half of April (+0.2 °C; p = 0.014). Daily average oak pollen counts correlated positively with mean and maximum daily temperatures, and negatively with daily rainfall and daily mean relative humidity.

  3. Specific polyphenols and tannins are associated with defense against insect herbivores in the tropical oak Quercus oleoides.

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    Moctezuma, Coral; Hammerbacher, Almuth; Heil, Martin; Gershenzon, Jonathan; Méndez-Alonzo, Rodrigo; Oyama, Ken

    2014-05-01

    The role of plant polyphenols as defenses against insect herbivores is controversial. We combined correlative field studies across three geographic regions (Northern Mexico, Southern Mexico, and Costa Rica) with induction experiments under controlled conditions to search for candidate compounds that might play a defensive role in the foliage of the tropical oak, Quercus oleoides. We quantified leaf damage caused by four herbivore guilds (chewers, skeletonizers, leaf miners, and gall forming insects) and analyzed the content of 18 polyphenols (including hydrolyzable tannins, flavan-3-ols, and flavonol glycosides) in the same set of leaves using high performance liquid chromatography and mass spectrometry. Foliar damage ranged from two to eight percent per region, and nearly 90% of all the damage was caused by chewing herbivores. Damage due to chewing herbivores was positively correlated with acutissimin B, catechin, and catechin dimer, and damage by mining herbivores was positively correlated with mongolinin A. By contrast, gall presence was negatively correlated with vescalagin and acutissimin B. By using redundancy analysis, we searched for the combinations of polyphenols that were associated to natural herbivory: the combination of mongolinin A and acutissimin B had the highest association to herbivory. In a common garden experiment with oak saplings, artificial damage increased the content of acutissimin B, mongolinin A, and vescalagin, whereas the content of catechin decreased. Specific polyphenols, either individually or in combination, rather than total polyphenols, were associated with standing leaf damage in this tropical oak. Future studies aimed at understanding the ecological role of polyphenols can use similar correlative studies to identify candidate compounds that could be used individually and in biologically meaningful combinations in tests with herbivores and pathogens.

  4. Drought reduced monoterpene emissions from the evergreen Mediterranean oak Quercus ilex: results from a throughfall displacement experiment

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    S. Rambal

    2009-07-01

    Full Text Available The effects of water limitations on the emission of biogenic volatile organic compounds are not well understood. Experimental approaches studying drought effects in natural conditions are still missing. To address this question, a throughfall displacement experiment was set up in a natural forest of Quercus ilex, an evergreen Mediterranean oak emitting monoterpenes. Mature trees were exposed in 2005 and 2006 either to an additional drought, to irrigation or to natural drought (untreated control. In both years, absolute monoterpene emission rates as well as the respective standard factors of the trees exposed to normal and additional drought strongly declined during the drought periods. Monoterpene emissions were lower in year 2006 than in year 2005 (factor 2 due to a more pronounced summer drought period in this respective year. We observed a significant difference between the irrigation and additional drought or control treatment: irrigated trees emitted 82% more monoterpenes during the drought period 2006 than the trees of the other treatments. However, no significant effect on monoterpene emission was observed between normal and additional drought treatments, despite a significant effect on leaf water potential and photochemical efficiency. During the development of drought, monoterpene emissions responded exponentially rather than linearly to decreasing leaf water potential. Emissions rapidly declined when the water potential dropped below −2 MPa and photosynthesis was persistently inhibited. Monoterpene synthase activities measured in vitro showed no clear reduction during the same period. From our results we conclude that drought significantly reduces monoterpene fluxes of Mediterranean Holm oak forest into the atmosphere due to a lack of primary substrates coming from photosynthetic processes.

  5. Recent climate hiatus revealed dual control by temperature and drought on the stem growth of Mediterranean Quercus ilex.

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    Lempereur, Morine; Limousin, Jean-Marc; Guibal, Frédéric; Ourcival, Jean-Marc; Rambal, Serge; Ruffault, Julien; Mouillot, Florent

    2017-01-01

    A better understanding of stem growth phenology and its climate drivers would improve projections of the impact of climate change on forest productivity. Under a Mediterranean climate, tree growth is primarily limited by soil water availability during summer, but cold temperatures in winter also prevent tree growth in evergreen forests. In the widespread Mediterranean evergreen tree species Quercus ilex, the duration of stem growth has been shown to predict annual stem increment, and to be limited by winter temperatures on the one hand, and by the summer drought onset on the other hand. We tested how these climatic controls of Q. ilex growth varied with recent climate change by correlating a 40-year tree ring record and a 30-year annual diameter inventory against winter temperature, spring precipitation, and simulated growth duration. Our results showed that growth duration was the best predictor of annual tree growth. We predicted that recent climate changes have resulted in earlier growth onset (-10 days) due to winter warming and earlier growth cessation (-26 days) due to earlier drought onset. These climatic trends partly offset one another, as we observed no significant trend of change in tree growth between 1968 and 2008. A moving-window correlation analysis revealed that in the past, Q. ilex growth was only correlated with water availability, but that since the 2000s, growth suddenly became correlated with winter temperature in addition to spring drought. This change in the climate-growth correlations matches the start of the recent atmospheric warming pause also known as the 'climate hiatus'. The duration of growth of Q. ilex is thus shortened because winter warming has stopped compensating for increasing drought in the last decade. Decoupled trends in precipitation and temperature, a neglected aspect of climate change, might reduce forest productivity through phenological constraints and have more consequences than climate warming alone. © 2016 John

  6. 2-D GEL ELECTROPHORESIS MAP OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS TREATED WITH QUERCUS INFECTORIA GALL EXTRACT

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    Dayang Fredalina Basri

    2013-01-01

    Full Text Available The widespread outbreak of Methicillin-Resistant Staphylococcus Aureus (MRSA has caused clinical and epidemiological concern in hospital environment. The emergence of Vancomycin-Intermediate S. Aureus (VISA and, more recently, Vancomycin-Resistant S. Aureus (VRSA has further alarmed clinician and scientist worlwide. The objective of this study is to determine the optimum concentration of sample protein from MRSA after treatment with acetone extract from Quercus infectoria gall. Comparison of the Protein Expression Profile (PEP between the treated MRSA and untreated strain as control was obtained using 2-dimensional gel electrophoresis. The Minimum Inhibitory Concentration (MIC value of acetone extract of galls from Q. infectoria against two strains of MRSA; ATCC 33591 and PPUKM clinical isolate was determined by broth microdilution method. The MIC value of acetone extracts against both strains of MRSA was 0.3125 mg mL-1 compared to vancomycin (0.00195 mg mL-1. The optimum concentration of MRSA protein that produced the best resolution was 100 µg. Manifold technique was observed to produce a gel with better resolution and greater number of spot compared with the strip holder technique. This study showed that there were 7 protein spots that represented the increased in the protein expression of more than 2-fold in the MRSA treated with acetone extract of galls Q. infectoria compared to the untreated group. This preliminary study on the PEP of Q. infectoria galls extract-treated MRSA may provide an insight of its antimicrobial mechanism which could lead to the identification of target protein in the future development of a new effective regimen for the treatment of MRSA infections.

  7. Tree ring growth by core sampling at the CONECOFOR Permanent Monitoring Plots. The deciduous oak (Quercus cerris L. type

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    Maria Chiara MANETTI

    2002-09-01

    Full Text Available Radial growth analysis evaluates the ability of trees to grow under different site and environmental conditions, thus contributing to bio-ecological studies aimed at increasing understanding of forest stand evolution. Tree ring growth is analysed in five Permanent Monitoring Plots (PMPs dominated by Turkey oak (Quercus cerris L.. Common structural features of these PMPs are their origin (coppice forest and their current physiognomy as stored coppice and transitory crop. A dendroecological approach was used to analyse past radial stem growth, the influence of silvicultural background and stand age, as well as to compare the growth rhythm of stands in different site-indexes and environmental conditions. Tree coring was carried out at the time of the first inventory (winter 1996/97 by sampling 8 to 11 dominant and co-dominant trees representative of the upper storey in the buffer area of each PMP. The basic stem and crown growth variables were measured for each tree sampled and two cores collected at 1.30 m. Annual ring width was determined by the Tree Ring Measurement System SMIL3 and the data were elaborated by the ANAFUS software. Site mean curves and growth trend per social class in each stand were defined both by visual comparison and statistical analysis among individual tree series. The main results were as follows: i social differentiation becomes established earlier with better site indexes and higher tree densities; ii sensitivity to external disturbances is higher and more defined in the dominant class than in the co-dominant tree layer; iii competition cycles are clearly discernible and related to both stand density and site-index in young stands under natural evolution (stored coppices; iv when silvicultural interventions were performed in the past is quite visible readable in the stands under conversion into high forest (transitory crops; v the mean series per site are statistically related and common periods characterized by a

  8. Patterns of stomatal conductance among blue oak (Quercus douglasii) size classes and populations: implications for seedling establishment.

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    Matzner, Steven L; Rice, Kevin J; Richards, James H

    2003-08-01

    Quercus douglasii Hook. & Arn. (blue oak) is a deciduous white oak that is currently failing to regenerate throughout much of its range in California, USA. Patterns of water use were observed in adult trees, saplings and seedlings to determine if ontogenetic changes in water use occur, which might be important in the establishment of this long-lived perennial species in a Mediterranean-type system. Seasonal and diurnal stomatal conductance (g(s)), late-season predawn xylem water potentials (Psi(pre)), carbon isotopic ratio (delta(13)C) and soil water status were compared among the three size classes at three sites differing in mean precipitation and soil water characteristics. Comparisons were also made between microsites with and without regeneration (defined by the presence or absence of saplings). Overall patterns of water use were consistent among the three sites, except that, at the site with the highest rainfall, Q. douglasii plants had higher g(s) and more positive Psi(pre) values. Although no differences in water use patterns were found between regeneration and non-regeneration microsites, the observed ontogenetic differences in water use may have important implications for Q. douglasii establishment. Compared with adult trees and saplings, seedlings had higher gas exchange rates during periods of high soil water content (early in the season and in the morning). Seedling g(s) was correlated with percent extractable soil water (ESW) throughout the season; adult tree and sapling g(s) was correlated with ESW between June and September. Despite experiencing greater water stress (indicated by more negative Psi(pre) values) than older trees, seedlings had more negative delta(13)C values, implying lower water-use efficiencies.

  9. Early summer drought stress during the first growing year stimulates extra shoot growth in oak seedlings (Quercus petraea

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    Arion eTurcsán

    2016-02-01

    Full Text Available More severe summer droughts are predicted for mid-latitudes in Europe. To evaluate the impact on forest ecosystems and more specifically on forest regeneration, we studied the response to summer drought in oak seedlings (Quercus petraea. Acorns were collected from different mother trees in three stands in Belgium, sown in pots and grown in non-heated greenhouse conditions. We imposed severe drought on the seedlings in early summer by first watering the pots to saturation and then stopping any watering. Weight of the pots and stomatal conductance were regularly measured. Re-watering followed this drought period of five weeks. Height of the seedlings and apical bud development were observed. Stomatal resistance increased towards the end of the experiment in the drought-treated group and was restored after re-watering. The seedlings from the drought treatment displayed a higher probability to produce additional shoot growth after re-watering (p ≤ 0.05. A higher competition for resources (two plants per pot increased this chance. Although this chance was also higher for smaller seedlings, the actual length of the extra growth after re-watering was higher for larger seedlings (p ≤ 0.01. Both in the drought-treated and in the control group the autochthonous provenance growing on a xeric site produced less extra shoots compared to the two other provenances. Finally, stressed plants showed less developed apical buds compared to the control group after re-watering, suggesting a phenological effect on the growth cycle of oaks (p ≤ 0.0001. The higher chance for an extra shoot growth after the drought period can be considered as a compensation for the induced growth arrest during the drought period.

  10. How drought severity constrains gross primary production(GPP) and its partitioning among carbon pools in a Quercus ilex coppice?

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    Rambal, S.; Lempereur, M.; Limousin, J. M.; Martin-StPaul, N. K.; Ourcival, J. M.; Rodríguez-Calcerrada, J.

    2014-12-01

    The partitioning of photosynthates toward biomass compartments plays a crucial role in the carbon (C) sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought-prone forests. We analyzed the fate of gross primary production (GPP) in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Carbon fluxes between the ecosystem and the atmosphere were measured with an eddy covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns, and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy covariance fluxes with annual net primary productions (NPP), we managed to close a C budget and derive values of autotrophic, heterotrophic respirations and carbon-use efficiency (CUE; the ratio between NPP and GPP). Average values of yearly net ecosystem production (NEP), GPP and Reco were 282, 1259 and 977 g C m-2. The corresponding aboveground net primary production (ANPP) components were 142.5, 26.4 and 69.6 g C m-2 for leaves, reproductive effort (flowers and fruits) and stems, respectively. NEP, GPP and Reco were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected - the stem growth - to the least affected - the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease less drastically in response to drought than GPP and NPP did, probably due to drought acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem, and

  11. Chronological Sequence of Leaf Phenology, Xylem and Phloem Formation and Sap Flow of Quercus pubescens from Abandoned Karst Grasslands

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    Lavrič, Martina; Eler, Klemen; Ferlan, Mitja; Vodnik, Dominik; Gričar, Jožica

    2017-01-01

    Intra-annual variations in leaf development, radial growth, including the phloem part, and sap flow have rarely been studied in deciduous trees from drought-prone environments. In order to understand better the chronological order and temporal course of these processes, we monitored leaf phenology, xylem and phloem formation and sap flow in Quercus pubescens from abandoned karst grasslands in Slovenia during the growing season of 2014. We found that the initial earlywood vessel formation started before bud opening at the beginning of April. Buds started to open in the second half of April and full leaf unfolding occurred by the end of May. LAI values increased correspondingly with leaf development. About 28% of xylem and 22% of phloem annual increment were formed by the time of bud break. Initial earlywood vessels were fully lignified and ready for water transport, indicating that they are essential to provide hydraulic conductivity for axial water flow during leaf development. Sap flow became active and increasing contemporarily with leaf development and LAI values. Similar early spring patterns of xylem sap flow and LAI denoted that water transport in oaks broadly followed canopy leaf area development. In the initial 3 weeks of radial growth, phloem growth preceded that of xylem, indicating its priority over xylem at the beginning of the growing season. This may be related to the fact that after bud break, the developing foliage is a very large sink for carbohydrates but, at the same time, represents a small transpirational area. Whether the interdependence of the chronological sequence of the studied processes is fixed in Q. pubescens needs to be confirmed with more data and several years of analyses, although the ‘correct sequence’ of processes is essential for synchronized plant performance and response to environmental stress. PMID:28321232

  12. Comparing carbon isotope composition of bulk wood and holocellulose from Quercus cerris, Fraxinus ornus and Pinus radiata tree rings

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    D’Alessandro CM

    2004-01-01

    Full Text Available Tree-ring δ13C is widely employed in ecophysiological studies, because it represents an integrated proxy of the ratio between photosynthesis (A and stomatal conductance (g, which expresses the intrinsic water use efficiency (iWUE, strongly affected by the environmental conditions experienced by the plant during its life span. Tree-ring δ13C also reflects long term variations of atmospheric CO2 concentration and of its carbon isotope composition, partly due to increasing anthropogenic emissions. Carbon isotope abundances in tree rings can be assessed on bulk wood as well as on wood? biochemical components, wich show different δ13C values because of secondary discrimination during biosynthesis.We present the results of a comparison between δ13C values of bulk wood and holocellulose samples obtained from the last three (1999, 2000 and 2001 annual growth rings of two hardwood (Quercus cerris L. and Fraxinus ornus L. and one conifer (Pinus radiata D. Don, species. We found that δ13C values differed significantly among tree species, both in the case of holocellulose and bulk wood, but only in the case of P. radiata bulk wood samples tend to provide more negative δ13C values than holocellulose, as reported in the literature. We suggest that, at least for the two hardwood species studied, bulk wood is a suitable material to work with for δ13C assessment, whilst in P. radiata holocellulose could provide a more stable and reliable index, when studying plant ecophysiological responses to changing environmental conditions.

  13. Sensitivity of terpene emissions to drought and fertilization in terpene-storing Pinus halepensis and non-storing Quercus ilex.

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    Blanch, Josep-Salvador; Peñuelas, Josep; Llusià, Joan

    2007-10-01

    We studied the effects of water stress, fertilization and time course on foliar volatile terpene emission rates by Quercus ilex and Pinus halepensis in a garden experiment. The terpenes mostly emitted by both species were alpha-pinene, beta-pinene, beta-myrcene and Delta(3)-carene. P. halepensis emission rates (average 31.45 microg g(-1) DM h(-1)) were similar to those of Q. ilex (average 31.71 microg g(-1) DM h(-1)). The effects of drought (reduction to one-third of full watering) and fertilization (250 kg N ha(-1), 250 kg P ha(-1), or both) were different depending on the species: the drought treatment significantly increased the terpene emissions from Q. ilex by 33%, and the fertilization treatments reduced the terpene emissions from P. halepensis by 38%. Terpene emission rates increased with time course in parallel to raising summer temperatures in P. halepensis and Q. ilex, whose emission rates were temperature related (r = 0.42 and r = 0.68, respectively) and light related (r = 0.32 and r = 0.57, respectively). There was a positive relationship for P. halepensis, and a negative relationship for Q. ilex, between emission rates and relative water contents. No relationship was found between emission rates and N or P foliar concentrations. The results of this study show complex species-specific responses with stronger and faster short-term responses in terpene-non-storing than in storing species and indicate that terpene emissions may significantly change in the warmer, drier and more fertilized conditions predicted for the next decades in the Mediterranean region.

  14. Responses and acclimation of Chinese cork oak (Quercus variabilis Bl.) to metal stress: the inducible antimony tolerance in oak trees.

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    Zhao, Xiulian; Zheng, Lingyu; Xia, Xinli; Yin, Weilun; Lei, Jingpin; Shi, Shengqing; Shi, Xiang; Li, Huiqing; Li, Qinghe; Wei, Yuan; Chang, Ermei; Jiang, Zeping; Liu, Jianfeng

    2015-08-01

    Antimony (Sb) pollution has become a pressing environmental problem in recent years. Trees have been proven to have great potential for the feasible phytomanagement; however, little is known about Sb retention and tolerance in trees. The Chinese cork oak (Quercus variabilis Bl.) is known to be capable of growth in soils containing high concentrations of Sb. This study explored in detail the retention and acclimation of Q. variabilis under moderate and high external Sb levels. Results revealed that Q. variabilis could tolerate and accumulate high Sb (1623.39 mg kg(-1) DW) in roots. Dynamics of Sb retention in leaves, stems, and roots of Q. variabilis were different. Leaf Sb remained at a certain level for several weeks, while in roots and stems, Sb concentrations continued to increase. Sb damaged tree's PSII reaction cores but elicited defense mechanism at the donor side of PSII. It affected the electron transport flow after QA (-) more strongly than the oxygen-evolving complex and light-harvesting pigment-protein complex II. Sb also decreased leaf chlorophyll concentrations and therefore inhibited plant growth. During acclimation to Sb toxicity, Sb concentrations in leaves, stems, and roots decreased, with photosynthetic activity and pigments recovering to normal levels by the end of the experiment. These findings suggest that Sb tolerance in Q. variabilis is inducible. Acclimation seems to be related to homeostasis of Sb in plants. Results of this study can provide useful information for trees breeding and selection of Sb phytomanagement strategies, exploiting the established ability of Q. variabilis to transport, delocalize in the leaves, and tolerate Sb pollutions.

  15. Relative importance of various regeneration mechanisms in different restoration stages of Quercus variabilis forest after selective logging

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    Yaoqin Xue

    2014-08-01

    Full Text Available Aim of study: Quercus variabilis (Chinese cork oak reproduces asexually and sexually. This study aimed to determine the status and growth of asexual and sexual recruits of Q. variabilis in different forest recovery stages.Area of study: Three selective logged stands and one unlogged stand in Q. variabilis forest, Shaanxi Province, China.Material and Methods: Origin, number, basal diameter, height and size structure of Q. variabilis shoots (height ≤200 cm were investigated in the plots of 5, 10, and 20-years post-logging stands and unlogged stand. Effects of recovery stage on the density and growth of the three original recruits (stump sprouts, stem base sprouts and true seedlings were analysis by One-way ANOVA.Main results: Sprouts dominated logged stands, whereas true seedlings dominated unlogged stand, stem base sprouts only existed in 20-years post-logging and unlogged stands. Stump sprout density and sprout number per stump both declined with extended post-logging time. True seedlings density increased from 7 to 20 shoots/100 m2 as the postlogging time extended, and peaked in unlogged stand (94 shoots/100 m2. An ongoing size structure was observed in true seedlings in all stands. Stump sprouts were taller and greater than true seedlings.Research highlights: Stump sprouts contributed more to Q. variabilis forest recovery in the early stage after disturbance. The contribution of true seedlings was limited in the same stage, but they were beneficial for population long-term development. Stem base sprouts were most likely to be a survival strategy rather than a reproductive strategy.Key words: asexual reproduction; true seedling; post-logging time; Chinese cork oak.

  16. Fragmentation effect in the leaf morphometry and environment of Quercus germana Schldl. & Cham. (Fagaceae in Xalapa, Veracruz

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    Anantli Martínez-Munguía

    2015-01-01

    Full Text Available Quercus germana es una especie endémica del bosque mesófilo de montaña de México. La presión de selección que la fragmentación y los cambios ambientales ejercen, sugieren diferenciación fenotípica. Por lo anterior, la relación de la diferenciación foliar de Q. germana con la fragmentación y las condiciones ambientales se evaluó en seis sitios del bosque mesófilo de Xalapa, Veracruz. Para ello, se colectaron 10 hojas de las ramas nones de 30 individuos por sitio; se midieron 10 características morfométricas foliares y siete ambientales. Los análisis de varianza se realizaron con el modelo linear generalizado; se utilizó un análisis discriminante, se construyeron árboles de ligamiento UPGMA y se proyectaron las poblaciones tridimensionalmente. Las distancias de Mahalanobis se compararon con una prueba de Mantel para estimar la relación morfométrica y ambiental. Las variables morfológicas que mejor separan los sitios son mucrones, nervaduras y tamaño del peciolo. Ambientalmente, las variables más discriminantes son luz, temperatura y pérdida de humedad. La prueba de Mantel no mostró relación entre las diferencias morfométricas y ambientales (r = 0.090, P = 0.306. Las subpoblaciones de Q. germana son morfológicamente diferentes a pesar de la distancia corta que las separa, lo cual indica que posiblemente son afectadas por la fragmentación aún sin influencia ambiental.

  17. Do Quercus ilex woodlands undergo abrupt non-linear functional changes in response to human disturbance along a climatic gradient?

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    Bochet, Esther; García-Fayos, Patricio; José Molina, Maria; Moreno de las Heras, Mariano; Espigares, Tíscar; Nicolau, Jose Manuel; Monleon, Vicente

    2017-04-01

    Theoretical models predict that drylands are particularly prone to suffer critical transitions with abrupt non-linear changes in their structure and functions as a result of the existing complex interactions between climatic fluctuations and human disturbances. However, so far, few studies provide empirical data to validate these models. We aim at determining how holm oak (Quercus ilex) woodlands undergo changes in their functions in response to human disturbance along an aridity gradient (from semi-arid to sub-humid conditions), in eastern Spain. For that purpose, we used (a) remote-sensing estimations of precipitation-use-efficiency (PUE) from enhanced vegetation index (EVI) observations performed in 231x231 m plots of the Moderate Resolution Imaging Spectroradiometer (MODIS); (b) biological and chemical soil parameter determinations (extracellular soil enzyme activity, soil respiration, nutrient cycling processes) from soil sampled in the same plots; (c) vegetation parameter determinations (ratio of functional groups) from vegetation surveys performed in the same plots. We analyzed and compared the shape of the functional change (in terms of PUE and soil and vegetation parameters) in response to human disturbance intensity for our holm oak sites along the aridity gradient. Overall, our results evidenced important differences in the shape of the functional change in response to human disturbance between climatic conditions. Semi-arid areas experienced a more accelerated non-linear decrease with an increasing disturbance intensity than sub-humid ones. The proportion of functional groups (herbaceous vs. woody cover) played a relevant role in the shape of the functional response of the holm oak sites to human disturbance.

  18. El milagro de regenerar en especies mediterráneas de Quercus. ¿Cómo serán los bosques del futuro?

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    I. M. Pérez Ramos

    2014-01-01

    Full Text Available Las especies de Quercus son especialmente vulnerables durante las fases iniciales de su ciclo regenerativo debido a la limitación impuesta por un conjunto de factores, que podrían llegar a poner en riesgo la persistencia de sus poblaciones y alterar la dinámica de las comunidades de las que forman parte. En este artículo he sintetizado los principales factores que dificultan el reclutamiento en especies mediterráneas de Quercus, he discutido el papel que juega en este proceso la heterogeneidad de microhábitats, y he revisado los efectos ecológicos del esperable incremento de aridez sobre la regeneración natural de estas especies. Entre los principales factores que limitan el reclutamiento de estas especies se encuentran:(i las altas tasas de depredación post-dispersiva de semillas; (ii los efectos negativos sobre adultos y plántulas ocasionados por la invasión de oomicetos patógenos, y (iii la fuerte dependencia de la planta al régimen de precipitaciones, tanto para la producción de semillas como para el establecimiento exitoso de plántulas. El éxito en la regeneración de especies de Quercus está fuertemente condicionado por el tipo de microhábitat al que es dispersada la semilla, con importantes diferencias a lo largo de la ontogenia de la planta (por ejemplo, cuando se comparan las fases de semilla y plántula. En un contexto de cambio climático, sería esperable que el aumento de aridez limite aún más la capacidad de reclutamiento natural de estas especies, altere sus patrones de abundancia relativa en la comunidad y potencie el papel facilitador del matorral como elemento clave para el establecimiento exitoso de plántulas y brinzales

  19. 倒卵叶青冈——广西壳斗科一新记录种%Quercus arbutifolia, a new record species of Fagaceae in Guangxi

    Institute of Scientific and Technical Information of China (English)

    邓敏; 曹明; 席世丽; 曹小燕

    2011-01-01

    报道了广西壳斗科植物一新记录种——倒卵叶青冈,并对倒卵叶青冈的形态进行了补充描述,同时对该种的生存现状进行评价,为这一物种的保护提供基础资料.%A new distribution of record of Quercus arbuti folia in Guangxi, China is reported. An additional description and conservation status of the species is presented.

  20. Emergency Medical Service (EMS) Stations

    Data.gov (United States)

    Kansas Data Access and Support Center — EMS Locations in Kansas The EMS stations dataset consists of any location where emergency medical services (EMS) personnel are stationed or based out of, or where...

  1. Isolation and Characterization of a Lycopene ε-Cyclase Gene of <em>Chlorella em>(Chromochloris> <em>zofingiensis>. Regulation of the Carotenogenic Pathway by Nitrogen and Light

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    Maria Angeles Vargas

    2012-09-01

    Full Text Available The isolation and characterization of the lycopene ε-cyclase gene from the green microalga <em>Chlorella em>(Chromochloris> <em>zofingiensis> (<em>Czlcy-e> was performed. This gene is involved in the formation of the carotenoids α-carotene and lutein. <em>Czlcy-e> gene encoded a polypeptide of 654 amino acids. A single copy of <em>Czlcy-e> was found in <em>C. zofingiensisem>. Functional analysis by heterologous complementation in <em>Escherichia coliem> showed the ability of this protein to convert lycopene to δ-carotene. In addition, the regulation of the carotenogenic pathway by light and nitrogen was also studied in <em>C. zofingiensisem>. High irradiance stress did not increase mRNA levels of neither lycopene β<em>->cyclase gene (<em>lcy-b> nor lycopene ε-cyclase gene<em> em>(lcy-e> as compared with low irradiance conditions, whereas the transcript levels of <em>psy>, <em>pds>, <em>chyB> and <em>bkt> genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene. Nitrogen starvation <em>per seem> enhanced mRNA levels of all genes considered, except <em>lcy-e and pdsem>, but did not trigger the synthesis of astaxanthin, canthaxanthin nor zeaxanthin. The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of <em>bkt> gene, as compared with the effect of only high irradiance stress.

  2. <em>Angiostrongylus vasorumem> in red foxes (<em>Vulpes vulpesem> and badgers (<em>Meles melesem> from Central and Northern Italy

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    Marta Magi

    2010-06-01

    Full Text Available Abstract During 2004-2005 and 2007-2008, 189 foxes (<em>Vulpes vulpesem> and 6 badgers (<em>Meles melesem> were collected in different areas of Central Northern Italy (Piedmont, Liguria and Tuscany and examined for <em>Angiostrongylus vasorumem> infection. The prevalence of the infection was significantly different in the areas considered, with the highest values in the district of Imperia (80%, Liguria and in Montezemolo (70%, southern Piedmont; the prevalence in Tuscany was 7%. One badger collected in the area of Imperia turned out to be infected, representing the first report of the parasite in this species in Italy. Further studies are needed to evaluate the role played by fox populations as reservoirs of infection and the probability of its spreading to domestic dogs.
    Riassunto <em>Angiostrongylus vasorumem> nella volpe (<em>Vulpes vulpesem> e nel tasso (<em>Meles melesem> in Italia centro-settentrionale. Nel 2004-2005 e 2007-2008, 189 volpi (<em>Vulpes vulpesem> e 6 tassi (<em>Meles melesem> provenienti da differenti aree dell'Italia settentrionale e centrale (Piemonte, Liguria Toscana, sono stati esaminati per la ricerca di <em>Angiostrongylus vasorumem>. La prevalenza del nematode è risultata significativamente diversa nelle varie zone, con valori elevati nelle zone di Imperia (80% e di Montezemolo (70%, provincia di Cuneo; la prevalenza in Toscana è risultata del 7%. Un tasso proveniente dall'area di Imperia è risultato positivo per A. vasorum; questa è la prima segnalazione del parassita in tale specie in Italia. Ulteriori studi sono necessari per valutare il potenziale della volpe come serbatoio e la possibilità di diffusione della parassitosi ai cani domestici.

    doi:10.4404/hystrix-20.2-4442

  3. Leaf morphological variability and intraspecific taxonomic units for pedunculate oak and grayish oak (genus Quercus L., series Pedunculatae Schwz.) in Southern Carpathian Region (Romania).

    Science.gov (United States)

    Apostol, Ecaterina Nicoleta; Curtu, Alexandru Lucian; Daia, Liviu Mihai; Apostol, Bogdan; Dinu, Cristiana Georgeta; Şofletea, Neculae

    2017-07-26

    Even though pedunculate oak (Quercus robur L.) and grayish oak (Quercus pedunculiflora K. Koch) have different ecological requirements, they have been considered as having low differentiation at the level of morphological traits and genetic variation. The leaf morphology for 862 trees has been assessed in 16 natural populations, seven of Q. robur, eight of Q. pedunculiflora and a mixed forest were both taxa coexist. In total, fifteen descriptors have been analysed by using discriminant analysis, while it was found that with only four out of the fifteen leaf traits (abaxial pubescence, abaxial colour of the leaf, petiole length and basal shape of lamina) the two taxa could be clearly differentiated. A dendrogram has been constructed on the basis of these traits, where the populations of each taxon have been clustered together. PU and CL traits of Q. pedunculiflora were discussed for their adaptive value for drought resistance in the steppe habitats occupied by this taxon. Using the leaves' morphological descriptors and data from the literature, intra-taxonomic units (varieties, forms and sub-forms) have been identified in all analysed populations. Eight intraspecific units for Q. robur and six for Q. pedunculiflora have been identified in the investigated area. An analysis of spatial distribution of the two taxa and of their intraspecific units has been performed using maps of ecoregions for the study area. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Effect of high-pressure homogenization on the physical and antioxidant properties of Quercus resinosa infusions encapsulated by spray-drying.

    Science.gov (United States)

    Rocha-Guzmán, Nuria Elizabeth; Gallegos-Infante, José Alberto; González-Laredo, Rubén Francisco; Harte, Federico; Medina-Torres, Luis; Ochoa-Martínez, Luz Araceli; Soto-García, Marcela

    2010-06-01

    Quercus resinosa leaves are used in northern Mexico as a refreshing beverage rich in polyphenolic compounds. These leaves show astringency and hence need taste masking for incorporating in a food product. They also interact with many other food components and are not very stable to food processing environments, thus it is important to protect them and a common way is by encapsulation. In the present study the use of encapsulation by spray-drying of Quercus resinosa leaves infusions was evaluated. Q. resinosa leaves were collected, air dried, and milled prior to infusion preparation. Lactose-sodium caseinate blends at 3 different proportions (11 : 4%, 9 : 6%, and 7 : 8%) were dispersed with a constant amount of lyophilized infusion (0.075%) and processed under high-pressure homogenization (0, 100, 200, 300 MPa). Total phenolic content, DPPH kinetic analysis, deoxy-D-ribose oxidation inhibition, rheological evaluation, and particle size analysis were performed to evaluate the obtained capsules. High antioxidant activity was shown by capsules despite their very low concentration when inhibiting deoxy-D-ribose oxidation. Chain breaking rate was related to polyphenolic concentration in capsules. Using lactose-caseinate blends produces capsules of submicron to nanometer size that retain the good antioxidant capacities of original infusions.

  5. Growth-Climate Response of Young Turkey Oak (Quercus cerris L. Coppice Forest Stands along Longitudinal Gradient in Albania

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    Merita Stafasani

    2015-06-01

    Full Text Available Background and Purpose: Turkey oak (Quercus cerris L. is the most widespread species in Albania and less investigated from dendroclimatological point of view. Previous studies have reported that Q. cerris is sensitive to the environment when growing at different latitudes and ecological conditions. Based on this fact we have explored the response of different Q. cerris populations located along the longitudinal gradient. Materials and Methods: The stem discs were sampled from six sites (Kukes, Diber, Rreshen, Ulez, Elbasan, Belsh along longitudinal gradient ranging from north-east to central Albania. All oak forests stands grow under the influence of specific local Mediterranean climate. Tree-ring widths were measured to the nearest 0.001 mm using a linear table, LINTAB and the TSAP-Win program. Following the standard dendrochronological procedures residual tree-ring width chronologies were built for each site. Statistical parameters commonly used in dendrochronology were calculated for each site chronology. Relations between the tree-ring chronologies were explored using Hierarchical Factor Classification (HFC and Principal Component Analysis (PCA, while the radial growth-climate relationship was analyzed through correlation analysis using a 19-month window from April in the year prior to tree-ring formation (year t - 1 until October in the year of growth (year t. Results and Conclusions: The length of the site chronologies ranged from 16 to 36 years, with the Elbasan site chronology being the longest and the Belsh site chronology the shortest one. Trees at lower elevation were younger than trees at higher elevation. Statistical parameters (mean sensitivity (MS and auto correlation (AC of site chronologies were different among them and lower values of AC1 showed a weaker dependence of radial growth from climatic conditions of the previous growing year. Principal component analysis showed that Belsh, Rreshen and Elbasan site chronologies were

  6. Introgression Threatens the Genetic Diversity of Quercus austrocochinchinensis (Fagaceae), an Endangered Oak: A Case Inferred by Molecular Markers

    Science.gov (United States)

    An, Miao; Deng, Min; Zheng, Si-Si; Jiang, Xiao-Long; Song, Yi-Gang

    2017-01-01

    Natural introgression can cause negative effects where rare species experience genetic assimilation and invade by their abundant congeners. Quercus austrocochinchinensis and Q. kerrii (subgenus Cyclobalanopsis) are a pair of closely related species in the Indo-China area. Morphological intermediates of the two species have been reported in this region. In this study, we used AFLP, SSR and two key leaf morphological diagnostic traits to study the two Q. austrocochinchinensis populations, two pure Q. kerrii and two putative hybrid populations in China. Rates of individual admixture were examined using the Bayesian clustering programs STRUCTURE and NewHybrids, with no a priori species assignment. In total, we obtained 151 SSR alleles and 781 polymorphic loci of AFLP markers. Population differentiation inferred by SSR and AFLP was incoherent with recognized species boundaries. Bayesian admixture analyses and principal coordinate analysis identified more hybrids and backcrossed individuals than morphological intermediates in the populations. SSR inferred a wide genetic assimilation in Q. austrocochinchinensis, except for subpopulation D2 in the core area of Xi-Shuang-Ban-Na Nature Reserve (XSBN). However, AFLP recognized more Q. austrocochinchinensis purebreds than SSR. Analysis using NewHybrids on AFLP data indicated that these hybridized individuals were few F2 and predominantly backcrosses with both parental species. All these evidences indicate the formation of a hybrid swarm at XSBN where the two species co-exist. Both AFLP and SSR recognized that the core protected area of XSBN (D2) has a high percentage of Q. austrocochinchinensis purebreds and a unique germplasm. The Hainan population and the other subpopulations of XSBN of the species might have lost their genetic integrity. Our results revealed a clear genetic differentiation in the populations and subpopulations of Q. austrocochinchinensis and ongoing introgression between Q. austrocochinchinensis and Q

  7. Xylem and Leaf Functional Adjustments to Drought in Pinus sylvestris and Quercus pyrenaica at Their Elevational Boundary

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    Laura Fernández-de-Uña

    2017-07-01

    Full Text Available Climatic scenarios for the Mediterranean region forecast increasing frequency and intensity of drought events. Consequently, a reduction in Pinus sylvestris L. distribution range is projected within the region, with this species being outcompeted at lower elevations by more drought-tolerant taxa such as Quercus pyrenaica Willd. The functional response of these species to the projected shifts in water availability will partially determine their performance and, thus, their competitive success under these changing climatic conditions. We studied how the cambial and leaf phenology and xylem anatomy of these two species responded to a 3-year rainfall exclusion experiment set at their elevational boundary in Central Spain. Additionally, P. sylvestris leaf gas exchange, water potential and carbon isotope content response to the treatment were measured. Likewise, we assessed inter-annual variability in the studied functional traits under control and rainfall exclusion conditions. Prolonged exposure to drier conditions did not affect the onset of xylogenesis in either of the studied species, whereas xylem formation ceased 1–3 weeks earlier in P. sylvestris. The rainfall exclusion had, however, no effect on leaf phenology on either species, which suggests that cambial phenology is more sensitive to drought than leaf phenology. P. sylvestris formed fewer, but larger tracheids under dry conditions and reduced the proportion of latewood in the tree ring. On the other hand, Q. pyrenaica did not suffer earlywood hydraulic diameter changes under rainfall exclusion, but experienced a cumulative reduction in latewood width, which could ultimately challenge its hydraulic performance. The phenological and anatomical response of the studied species to drought is consistent with a shift in resource allocation under drought stress from xylem to other sinks. Additionally, the tighter stomatal control and higher intrinsic water use efficiency observed in drought

  8. Potential of two submontane broadleaved species (Acer opalus, Quercus pubescens) to reveal spatiotemporal patterns of rockfall activity

    Science.gov (United States)

    Favillier, Adrien; Lopez-Saez, Jérôme; Corona, Christophe; Trappmann, Daniel; Toe, David; Stoffel, Markus; Rovéra, Georges; Berger, Frédéric

    2015-10-01

    Long-term records of rockfalls have proven to be scarce and typically incomplete, especially in increasingly urbanized areas where inventories are largely absent and the risk associated with rockfall events rises proportionally with urbanization. On forested slopes, tree-ring analyses may help to fill this gap, as they have been demonstrated to provide annually-resolved data on past rockfall activity over long periods. Yet, the reconstruction of rockfall chronologies has been hampered in the past by the paucity of studies that include broadleaved tree species, which are, in fact, quite common in various rockfall-prone environments. In this study, we test the sensitivity of two common, yet unstudied, broadleaved species - Quercus pubescens Willd. (Qp) and Acer opalus Mill. (Ao) - to record rockfall impacts. The approach is based on a systematic mapping of trees and the counting of visible scars on the stem surface of both species. Data are presented from a site in the Vercors massif (French Alps) where rocks are frequently detached from Valanginian limestone and marl cliffs. We compare recurrence interval maps obtained from both species and from two different sets of tree structures (i.e., single trees vs. coppice stands) based on Cohen's k coefficient and the mean absolute error. A total of 1230 scars were observed on the stem surface of 847 A. opalus and Q. pubescens trees. Both methods yield comparable results on the spatial distribution of relative rockfall activity with similar downslope decreasing recurrence intervals. Yet recurrence intervals vary significantly according to tree species and tree structure. The recurrence interval observed on the stem surface of Q. pubescens exceeds that of A. opalus by > 20 years in the lower part of the studied plot. Similarly, the recurrence interval map derived from A. opalus coppice stands, dominant at the stand scale, does not exhibit a clear spatial pattern. Differences between species may be explained by the bark

  9. Warming and drought differentially influence the production and resorption of elemental and metabolic nitrogen pools in Quercus rubra.

    Science.gov (United States)

    Suseela, Vidya; Tharayil, Nishanth; Xing, Baoshan; Dukes, Jeffrey S

    2015-11-01

    The process of nutrient retranslocation from plant leaves during senescence subsequently affects both plant growth and soil nutrient cycling; changes in either of these could potentially feed back to climate change. Although elemental nutrient resorption has been shown to respond modestly to temperature and precipitation, we know remarkably little about the influence of increasing intensities of drought and warming on the resorption of different classes of plant metabolites. We studied the effect of warming and altered precipitation on the production and resorption of metabolites in Quercus rubra. The combination of warming and drought produced a higher abundance of compounds that can help to mitigate climatic stress by functioning as osmoregulators and antioxidants, including important intermediaries of the tricarboxylic acid (TCA) cycle, amino acids including proline and citrulline, and polyamines such as putrescine. Resorption efficiencies (REs) of extractable metabolites surprisingly had opposite responses to drought and warming; drought treatments generally increased RE of metabolites compared to ambient and wet treatments, while warming decreased RE. However, RE of total N differed markedly from that of extractable metabolites such as amino acids; for instance, droughted plants resorbed a smaller fraction of elemental N from their leaves than plants exposed to the ambient control. In contrast, plants in drought treatment resorbed amino acids more efficiently (>90%) than those in ambient (65-77%) or wet (42-58%) treatments. Across the climate treatments, the RE of elemental N correlated negatively with tissue tannin concentration, indicating that polyphenols produced in leaves under climatic stress could interfere with N resorption. Thus, senesced leaves from drier conditions might have a lower nutritive value to soil heterotrophs during the initial stages of litter decomposition despite a higher elemental N content of these tissues. Our results suggest that N

  10. Adaptive genetic variability and differentiation of Croatian and Austrian Quercus robur L. populations at a drought prone field trial

    Directory of Open Access Journals (Sweden)

    Saša Bogdan

    2017-07-01

    Full Text Available Provenance trials, where populations of different geographical origin are tested in a common environment (common garden test, are a tool suited to allow the study of intraspecific adaptive genetic variation. Research of pedunculate oak (Quercus robur L. adaptive genetic variability through analyses of populations in common garden tests has a long tradition. However, pedunculated oak populations originating south-eastern from the Alps have been scarcely studied in this way. This study addresses the adaptive genetic variability and differentiation of pedunculate oak populations originating from Austria and Croatia in a provenance/progeny field trial. Studied plants were six years old and were growing at the trial for three years. After two years of unusually low precipitations height and survival were analysed. The total mean height of all plants in the trial was 137.8 cm and ranged from 123.0 cm to 151.8 cm. The overall mean survival rate was rather high (0.85. Mean population survival ranged from 0.64 to 0.94. Individual narrow-sense heritabilities (hi2, family mean heritabilities (hf2, the coefficients of additive genetic variation (CVA and quantitative genetic differentiation coefficients (QST were calculated. A multivariate regression tree (MRT analysis was used to determine the pattern of genetic differentiation of the populations. Individual heritabilities for height ranged between 0.00 and 0.39. Family mean heritabilities for height were rather low in most populations as well (<0.5. Family mean heritabilities for survival were higher than for height (ranging between 0.00 and 0.77. Calculated QST coefficients (0.25 for height and 0.14 for survival indicated between-population genetic differentiation. The populations were separated into two clusters by MRT analysis regarding a climatic variable, namely Hargreaves’ reference evapotranspiration. Populations originating from comparatively more humid habitats were grouped in the first

  11. Xylem-Transported Glucose as an Additional Carbon Source for Leaf Isoprene Formation in Quercus Robur L.

    Science.gov (United States)

    Graus, M.; Kreuzwieser, J.; Schnitzler, J.; Wisthaler, A.; Hansel, A.; Rennenberg, H.

    2003-04-01

    Isoprene is emitted from mature, photosynthesizing leaves of many plant species, particularly of trees. Current interest in understanding the biochemical and physiological mechanisms controlling isoprene formation is caused by the important role isoprene plays in atmospheric chemistry. Isoprene reacts with hydroxyl radicals (OH) thereby generating oxidizing agents such as ozone and organic peroxides. Ozone causes significant deterioration in air quality and can pose threats to human health therefore its control is a major goal in Europe and the United States. In recent years, much progress has been made in elucidating the pathways of isoprene biosynthesis. Nevertheless the regulatory mechanisms controlling isoprene emission are not completely understood. Light and temperature appear to be the main factors controlling short-term variations in isoprene emission. Exposure of plants to C-13 labeled carbon dioxide showed instantaneous assimilated carbon is the primary carbon source for isoprene formation. However, variations in diurnal and seasonal isoprene fluxes, which cannot be explained by temperature, light, and leaf development led to the suggestion that alternative carbon sources may exist contributing to isoprene emissions. The aim of the present study was to test whether xylem-transported carbohydrates act as additional sources for isoprene biosynthesis. For this purpose, [U-C-13] alpha-D-glucose was fed to photosynthesizing leaves via the xylem of Quercus robur L. seedlings and the incorporation of glucose derived C-13 into emitted isoprene was monitored in real time using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS). A rapid incorporation of C-13 from xylem-fed glucose into single (mass 70) and double (mass 71) C-13 labeled isoprene molecules was observed after a lag phase of approximately 5 to 10 minutes. This incorporation was temperature dependent and was highest (up to 13% C-13 of total carbon emitted as isoprene) at the temperature optimum of

  12. Flood-Ring Formation and Root Development in Response to Experimental Flooding of Young Quercus robur Trees

    Science.gov (United States)

    Copini, Paul; den Ouden, Jan; Robert, Elisabeth M. R.; Tardif, Jacques C.; Loesberg, Walter A.; Goudzwaard, Leo; Sass-Klaassen, Ute

    2016-01-01

    Spring flooding in riparian forests can cause significant reductions in earlywood-vessel size in submerged stem parts of ring-porous tree species, leading to the presence of ‘flood rings’ that can be used as a proxy to reconstruct past flooding events, potentially over millennia. The mechanism of flood-ring formation and the relation with timing and duration of flooding are still to be elucidated. In this study, we experimentally flooded 4-year-old Quercus robur trees at three spring phenophases (late bud dormancy, budswell, and internode expansion) and over different flooding durations (2, 4, and 6 weeks) to a stem height of 50 cm. The effect of flooding on root and vessel development was assessed immediately after the flooding treatment and at the end of the growing season. Ring width and earlywood-vessel size and density were measured at 25- and 75-cm stem height and collapsed vessels were recorded. Stem flooding inhibited earlywood-vessel development in flooded stem parts. In addition, flooding upon budswell and internode expansion led to collapsed earlywood vessels below the water level. At the end of the growing season, mean earlywood-vessel size in the flooded stem parts (upon budswell and internode expansion) was always reduced by approximately 50% compared to non-flooded stem parts and 55% compared to control trees. This reduction was already present 2 weeks after flooding and occurred independent of flooding duration. Stem and root flooding were associated with significant root dieback after 4 and 6 weeks and mean radial growth was always reduced with increasing flooding duration. By comparing stem and root flooding, we conclude that flood rings only occur after stem flooding. As earlywood-vessel development was hampered during flooding, a considerable number of narrow earlywood vessels present later in the season, must have been formed after the actual flooding events. Our study indicates that root dieback, together with strongly reduced hydraulic

  13. Influence of Temperature on Cambial Activity and Cell Differentiation in Quercus Sessiliflora and Acer Pseudoplatanus of Different Ages

    Directory of Open Access Journals (Sweden)

    Jožica Gričar

    2013-06-01

    Full Text Available We evaluated the response of active cambium of sessile oak (Quercus sessiliflora and sycamore maple (Acer pseudoplatanus to experimentally increased (20–22 °C and decreased (9–11 °C temperatures. Heating and cooling experiments on 150-year old Q. sessiliflora were performed during the growth season of 2007 and on 30-year old A. pseudoplatanus in 2008. In 2009, heating experiment was carried out on 30-year old Q. sessiliflora. For each treatment, two trees were selected of each species and sampled at 21-day intervals during the vegetation period and investigated by means of light microscopy. Continuously elevated temperatures slightly promoted the development of xylem cells in old Q. sessiliflora trees in the first month of cambial activity. However, no effect of elevated or decreased temperature was detected in the timing and dynamics of wood and phloem formation. The applied treatments, therefore, had no visible impact on the structure or width of the xylem or phloem increments in 2007. On the other hand, heating young A. pseudoplatanus trees provoked the development of epicormic shoots two months after the onset of the experiment and finally the death of trees. The cambium of those trees did not reactivate in 2008; xylem and phloem increments were consequently not formed. Low temperature treatments slowed down cell production at the very beginning of the growing season, but no alterations in wood or phloem formation dynamics or structure were observed later. The heating of young Q. sessiliflora trees caused the development of epicormic shoots and the death of trees four months after the experiment. The pattern of their dying was similar as in A. pseudoplatanus but with a two month delay. The observations indicate that tree age, thickness of dead bark and duration of the applied treatments influence the response of cambium. The development of dead bark is species specific and it occurs earlier in Q. sessiliflora than in A. pseudoplatanus

  14. Flash-flood impacts cause changes in wood anatomy of Alnus glutinosa, Fraxinus angustifolia and Quercus pyrenaica.

    Science.gov (United States)

    Ballesteros, J A; Stoffel, M; Bollschweiler, M; Bodoque, J M; Díez-Herrero, A

    2010-06-01

    Flash floods may influence the development of trees growing on channel bars and floodplains. In this study, we analyze and quantify anatomical reactions to wounding in diffuse-porous (Alnus glutinosa L.) and ring-porous (Fraxinus angustifolia Vahl. and Quercus pyrenaica Willd.) trees in a Mediterranean environment. A total of 54 cross-sections and wedges were collected from trees that had been injured by past flash floods. From each of the samples, micro-sections were prepared at a tangential distance of 1.5 cm from the injury to determine wounding-related changes in radial width, tangential width and lumen of earlywood vessels, and fibers and parenchyma cells (FPC). In diffuse-porous A. glutinosa, the lumen area of vessels shows a significant (non-parametric test, P-value <0.05) decrease by almost 39% after wounding. For ring-porous F. angustifolia and Q. pyrenaica, significant decreases in vessel lumen area are observed as well by 59 and 42%, respectively. Radial width of vessels was generally more sensitive to the decrease than tangential width, but statistically significant values were only observed in F. angustifolia. Changes in the dimensions of earlywood FPC largely differed between species. While in ring-porous F. angustifolia and Q. pyrenaica the lumen of FPC dropped by 22 and 34% after wounding, we observed an increase in FPC lumen area in diffuse-porous A. glutinosa of approximately 35%. Our data clearly show that A. glutinosa represents a valuable species for flash-flood research in vulnerable Mediterranean environments. For this species, it will be possible in the future to gather information on past flash floods with non-destructive sampling based on increment cores. In ring-porous F. angustifolia and Q. pyrenaica, flash floods leave less drastic, yet still recognizable, signatures of flash-flood activity through significant changes in vessel lumen area. In contrast, the use of changes in FPC dimensions appears less feasible for the determination of

  15. Variability of BVOC emissions from a Mediterranean mixed forest in southern France with a focus on Quercus pubescens

    Directory of Open Access Journals (Sweden)

    A.-C. Genard-Zielinski

    2014-06-01

    Full Text Available We aimed at quantifying Biogenic Volatiles Organic Compounds (BVOC emissions in June from three Mediterranean species located at the O3HP site (Southern France: Quercus pubescens, Acer monspessulanum and C. coggygria (for isoprene only. As Q. pubescens was shown to be the main BVOC emitter with isoprene representing ≈ 99% of the carbon emitted as BVOC, we mainly focused on this species. C. coggygria was found to be a non-isoprene emitter (no other BVOC were investigated. To fully understand both the canopy effect on Q. pubescens isoprene emission and the inter-individual variability (tree to tree and within canopy, diurnal variations of isoprene were investigated from nine branches (seven branches located to the top of canopy at ≈ 4 m Above Ground Level, and two inside the canopy at ≈ 2 m a.g.l.. Q. pubescens daily mean isoprene emission rates (ERd fluctuated between 23.1 and 97.7 μg C gDM−1 h−1 and were exponentially correlated with net assimilation (Pn. Q. pubescens daily mean Pn ranged between 5.4 and 13.8, and 2.8 and 6.4 μmol CO2 m−2 s−1 for sunlit and shaded branches respectively. Both ERd and isoprene emission factors (Is assessed according to Guenther et al. (1993 algorithm, varied by a factor of 4 among the sunlit branches. While sunlit branches ERm was clearly higher than for shaded branches, there was an non-significant variability on Is (58.5 to 76.5 μg C gDM−1 h−1. Diurnal variations of isoprene emission rates (ER for sunlit branches were also investigated. ER were detected at dawn 2 h after Pn became positive and, exponentially dependent on Pn. Diurnal variations of ER were not equally well described along the day by temperature (CT and light (CL parameters according to G93 algorithm. Temperature had more impact than PAR in the morning emission increase. ER was no more correlated to CL × CT between solar noon (maximum ER and mid-afternoon, possibly due to thermal stress of the plant. A comparison between

  16. <em>An entem>-Kaurane-Type Diterpene in <em>Croton antisyphiliticusem> Mart.

    Directory of Open Access Journals (Sweden)

    Ana Maria Pereira

    2012-07-01

    Full Text Available <em>Croton antisyphiliticus em>is a medicinal plant widely used in the treatment of microbial infections, especially those affecting the genital tract. Crude extract, fractions and pure compound isolated from roots of this species were investigated to validate their antimicrobial activity against <em>Escherichia coliem> and <em>Staphylococcus aureusem>. The compound <em>ent>-kaur-16-en-18-oic acid was isolated as a major component (0.7% of crude extract, and its MIC value determined against <em>S. aureusem> (ATCC 6538 was 250 μg/mL. This is the first phytochemical work on the species monitored with antimicrobial assay.

  17. Expression of Selected <em>Ginkgo em>>biloba em>Heat Shock Protein Genes After Cold Treatment Could Be Induced by Other Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Feng Xu

    2012-05-01

    Full Text Available Heat shock proteins (HSPs play various stress-protective roles in plants. In this study, three <em>HSP> genes were isolated from a suppression subtractive hybridization (SSH cDNA library of <em>Ginkgo bilobaem> leaves treated with cold stress. Based on the molecular weight, the three genes were designated <em>GbHSP16.8em>, <em>GbHSP17em> and <em>GbHSP70em>. The full length of the three genes were predicted to encode three polypeptide chains containing 149 amino acids (Aa, 152 Aa, and 657 Aa, and their corresponding molecular weights were predicted as follows: 16.67 kDa, 17.39 kDa, and 71.81 kDa respectively. The three genes exhibited distinctive expression patterns in different organs or development stages. <em>GbHSP16.8em> and <em>GbHSP70em> showed high expression levels in leaves and a low level in gynoecia, <em>GbHSP17em> showed a higher transcription in stamens and lower level in fruit. This result indicates that <em>GbHSP16.8em> and <em>GbHSP70 em>may play important roles in <em>Ginkgo> leaf development and photosynthesis, and <em>GbHSP17em> may play a positive role in pollen maturation. All three <em>GbHSPs> were up-regulated under cold stress, whereas extreme heat stress only caused up-regulation of <em>GbHSP70em>, UV-B treatment resulted in up-regulation of <em>GbHSP16.8em> and <em>GbHSP17em>, wounding treatment resulted in up-regulation of <em>GbHSP16.8em> and <em>GbHSP70em>, and abscisic acid (ABA treatment caused up-regulation of <em>GbHSP70em> primarily.

  18. Pesquisando em fontes visuais

    OpenAIRE

    Proença, Caio Carvalho; FFCH

    2012-01-01

    O presente ensaio pretende demonstrar reflexões sobre os usos da fotografia como fonte. Na primeira parte do ensaio procura-se demonstrar a experiência de um primeiro contato com a fonte visual, em especial a fotografia, para posteriormente entrar em contato com as diferentes formas metodológicas presente na pesquisa desta fonte. Em um segundo momento mostra-se alguns apontamentos sobre o método de pesquisa voltado à fonte visual fotográfica que auxiliam a pesquisa, contemplando a discussão s...

  19. Meteorologia em linha

    OpenAIRE

    2015-01-01

    DISPOSITIVO TÉCNICO-PEDAGÓGICO: CURSO DE METEOROLOGIA EM LINHA. Designamos por curso o sistema que resulta da relação entre um conjunto de componentes, dando unidade e identidade ao mesmo, incorporados na plataforma Versal: conjunto de 30 lições em vídeo, recursos complementares, valorização e contextualização do curso, orientação e acompanhamento desenhados e previstos, interação com os utilizadores do curso a partir do momento da sua edição aberta em linha. (https://versal.com/c/1fzwaz/m...

  20. A hipnose em triatletas

    OpenAIRE

    Szenészi, Daniela Scharamm

    2005-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Psicologia. Esta pesquisa objetivou investigar em atletas de triatlon a percepção das características da visualização da prova de Ironman e os seus componentes psicofisiológicos durante o transe hipnótico. Foram estudados 7 atletas do sexo masculino em 6 sessões de hipnose. Após cada sessão foi feita uma entrevista semi-estruturada e aplicado um questionário...

  1. Osteoartrites em equinos

    OpenAIRE

    Rocha, Francisco José Martins

    2008-01-01

    Dissertação de Mestrado Integrado em Medicina Veterinária A Osteoartrite (OA) é a principal causa de claudicação no cavalo de desporto e lazer, sendo uma afecção que tem grandes repercussões económicas. Este trabalho descreve algumas das características importantes da estrutura articular, bem como da sua fisiologia. Define a OA e todas as estruturas envolvidas no seu processo. Os mecanismos fisiopatológicos põem em evidência os factores de risco em causa e que determinam tod...

  2. Literatura em quadrinhos

    OpenAIRE

    Ferreira,Tânia Regina

    2015-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Literatura, Florianópolis, 2015. O objetivo desta tese é fazer o estudo do desfecho do romance de Lima Barreto, Triste fim de Policarpo Quaresma - (centenário de publicação em livro 1915-2015) - adaptado para as quatro versões homônimas em quadrinhos por: Edgar Vasques e Flávio Braga (Desiderata, 2010); Cesar Lobo e Luiz Antonio Aguiar (Ática, 2010); Lailson de Holanda...

  3. Melhores medicamentos em Pediatria

    OpenAIRE

    2014-01-01

    Resumo: Existem actualmente muitos medicamentos que são utilizados em crianças sem terem sido suficientemente estudados nas diferentes sub-populações pediátricas, com consequências preocupantes. O reconhecimento deste facto levou à criação de regras específicas na investigação de medicamentos pediátricos nos EUA, já em 1997. De igual forma, o Regulamento de Medicamentos para Uso Pediátrico aprovado em De zembro de 2006 pelo Parlamento Europeu, tem como objectivo a resolução deste problema no ...

  4. Characterization of <em>Erysiphe necatorem>-Responsive Genes in Chinese Wild <em>Vitis> <em>quinquangularis>

    Directory of Open Access Journals (Sweden)

    Xiping Wang

    2012-09-01

    Full Text Available Powdery mildew (PM, caused by fungus <em>Erysiphe necatorem>, is one of the most devastating diseases of grapevine. To better understand grapevine-PM interaction and provide candidate resources for grapevine breeding, a suppression subtractive hybridization (SSH cDNA library was constructed from <em>E. necatorem>-infected leaves of a resistant Chinese wild <em>Vitis quinquangularisem> clone “Shang-24”. A total of 492 high quality expressed sequence tags (ESTs were obtained and assembled into 266 unigenes. Gene ontology (GO analysis indicated that 188 unigenes could be assigned with at least one GO term in the biological process category, and 176 in the molecular function category. Sequence analysis showed that a large number of these genes were homologous to those involved in defense responses. Genes involved in metabolism, photosynthesis, transport and signal transduction were also enriched in the library. Expression analysis of 13 selected genes by qRT-PCR revealed that most were induced more quickly and intensely in the resistant material “Shang-24” than in the sensitive <em>V. pseudoreticulata em>clone “Hunan-1” by<em> E. necatorem> infection. The ESTs reported here provide new clues to understand the disease-resistance mechanism in Chinese wild grapevine species and may enable us to investigate <em>E. necatorem>-responsive genes involved in PM resistance in grapevine germplasm.

  5. Synthesis, Reactions and Evaluation of the Antimicrobial Activity of Some 4-(<em>p>-Halophenyl-4<em>H>-naphthopyran, Pyranopyrimidine and Pyranotriazolopyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Ashraf H. F. Abd El-Wahab

    2012-07-01

    Full Text Available A series of naphthopyran derivatives 3a–f were prepared. Reaction of <em>2-em>amino-4-(<em>p>-chlorophenyl-7-methoxy-4<em>H>-naphtho[2,1-<em>b>]pyran-3-carbonitrile (3b with Ac2O afforded two products, 2-acetylamino-7-methoxy-4-(<em>p>-chlorophenyl-4<em>H>-naphtho-[2,1-<em>b>]pyran-3-carbonitrile (4 and 10,11-dihydro-3-methoxy-9-methyl-12-(<em>p>-chloro-phenyl-12<em>H>-naphtho[2,1-<em>b>]pyran[2,3-<em>d>]pyrimidine-11-one (5 and treatment of 3b with benzoyl chloride gave the pyranopyrimidin-11-one derivative 6. While treatment of 3b with formamide afforded 11-amino-3-methoxy-12-(<em>p>-chlorophenyl-12<em>H>-naphtho[2,1-<em>b>]pyrano[2,3-<em>d>]pyrimidine (7. Reaction of 3b with triethyl orthoformate gave the corresponding 2-ethoxymethyleneamino-7-methoxy-4-(<em>p>-chlorophenyl-4<em>H>-naphtho-[2,1-<em>b>]pyran-3-carbonitrile (8. Hydrazinolysis of 8 in EtOH at room temperature yielded 10-amino-10,11-dihydro-11-imino-3-methoxy-12-(<em>p>-chlorophenyl-12<em>H>-naphtho[2,1-b]pyrano-[2,3-d]pyrimidine (9, while aminolysis of 8 with methylamine or dimethylamine gave the corresponding pyranopyrimidine and <em>N,N>-dimethylaminomethylene derivatives 10 and 11. Condensation of 9 with some carboxylic acid derivatives afforded triazolopyrimidine derivatives 12–16, while reaction of 9 with benzaldehyde gave 10-benzalamino-10,11-dihydro-11-imino-3-methoxy-12-(<em>p>-chlorophenyl12<em>H>-naphtho[2,1-<em>b>]pyrano[2,3-<em>d>]pyrimidine (17. The structures of the newly synthesized compounds were confirmed by spectral data. The

  6. International EMS Systems

    DEFF Research Database (Denmark)

    Langhelle, Audun; Lossius, Hans Morten; Silfvast, Tom;

    2004-01-01

    Emergency medicine service (EMS) systems in the five Nordic countries have more similarities than differences. One similarity is the involvement of anaesthesiologists as pre-hospital physicians and their strong participation for all critically ill and injured patients in-hospital. Discrepancies do...... exist, however, especially within the ground and air ambulance service, and the EMS systems face several challenges. Main problems and challenges emphasized by the authors are: (1) Denmark: the dispatch centres are presently not under medical control and are without a national criteria based system....... Access to on-line medical advice of a physician is not available; (2) Finland: the autonomy of the individual municipalities and their responsibility to cover for primary and specialised health care, as well as the EMS, and the lack of supporting or demanding legislation regarding the EMS; (3) Iceland...

  7. Preconceito em disfarce

    Directory of Open Access Journals (Sweden)

    João de Almeida

    2001-02-01

    Full Text Available

    0 presente estudo pretende analisar os significados básicos do texto "Preto e Branco", de F. Sabino, valendo-se de alguns modelos teóricos lingüísticos, principalmente de Greimas e de Pottier, em seqüência que vai da estrutura da narrativa e do percurso gerativo de sentido até as relações sêmicas, em especial.

  8. Digestion and body weight change in Tuj lambs receiving oak (Quercus hartwissiana) leaves with and without PEG

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, S. [Department of Physiology, Faculty of Veterinary Sciences, Kafkas University, Kars (Turkey)]. E-mail: yildizsedat@hotmail.com; Kaya, I.; Unal, Y.; Aksu Elmali, D.; Kaya, S.; Oncuer, A. [Department of Animal Nutrition, Faculty of Veterinary Sciences, Kafkas University, Kars (Turkey); Cenesiz, M.; Kaya, M. [Department of Physiology, Faculty of Veterinary Sciences, Kafkas University, Kars (Turkey)

    2005-08-19

    Quercus hartwissiana (oak) leaves are a potential alternative feed resource in the north-east of Turkey. The aim of the current study was to evaluate the effects of two levels (185 and 370 g/day) of dry oak leaves, in the presence (50 or 100 g/kg of dry oak leaves) or absence of polyethylene glycol (PEG 6000), on ruminal fermentation parameters (pH, short-chain fatty acids (SCFA), ammonia nitrogen (NH{sub 3}-N)), microbial nitrogen (N) supply, apparent diet digestibility, N retention, and body weight (BW) change in fat-tailed Tuj lambs (n = 42, initial BW 33.0 {+-} 0.7 kg). The lambs received at random one of the following diets for 60 days (on a dry matter basis, n = 6 per group): (1) control, no oak leaves and no PEG; (2) 185 g oak leaves; (3) 185 g oak leaves + 10 g PEG; (4) 185 g oak leaves + 20 g PEG; (5) 370 g oak leaves; (6) 370 g oak leaves + 20 g PEG; (7) 370 g oak leaves + 40 g PEG. All groups were given 272 g concentrate and varying amounts of hay (a mixture of chopped grass and alfalfa in the ratio 55:45), such that the amount of hay plus oak leaves was equal to 645 g. Ruminal fermentation parameters did not change with treatment (pH 6.50 {+-} 0.02, total SCFA 86.3 {+-} 2.1 mmol/L, NH{sub 3}-N = 207 {+-} 5 mg/L). Total CP digestibility (0.775, 0.714, 0.736, 0.748, 0.663, 0.690, 0.672; S.E.M. = 0.008, P < 0.001, for groups 1-7, respectively) and N retention (7.7, 6.8, 6.7, 7.5, 6.1, 5.8, 5.7 g/day; S.E.M. = 0.19, P < 0.05, for groups 1-7, respectively) were lowest but microbial N supply was highest in 370 g oak leaf group supplemented with PEG (6.51, 7.14, 11.45, 12.23, 9.03, 14.49, 14.39 g/day, S.E.M. = 0.76, P < 0.05, for groups 1-7, respectively). Final BW (32.5 {+-} 0.3 kg) did not differ among treatments (P > 0.05). These data suggest that: (1) PEG addition seems unnecessary as it did not improve CP digestibility, N retention and BW; and (2) Q. hartwissiana leaves may be used to replace at least half of hay in the ration of Tuj lambs without a

  9. Phytogeography of Quercus subg.Cyclobalanopsis%青冈亚属植物的地理分布

    Institute of Scientific and Technical Information of China (English)

    罗艳; 周浙昆

    2001-01-01

    Quercus subg. Cyclobalanopsis(Oerst.) Schneid. is an importantconstituent of broad leaved evergreen forests in subtropical and tropical regions of Asia. It contains 122 species distrbuted primarily within the Tropical Asia (Indo-Malaysia) phytogeographic province. A number of species were analyzed to develop a biogeographical and phytogenetic context for the diversity within subg. Cyclobalanopsis. Southern China and the north northern part of the Indo-Chine Peninsula show the highest species diversity and may be considered the two centers of diversity. A number of species in Malaysia were observed to have some plesiomorphic characters, and this region may be considered the center of origin and a key area of endemism. On the island of Borneo, the area of Kalimantan is richest in endemic species and the fossil species record resemble this fact. In contrast, the endemic species from Hainan and Taiwan are more derived. The endemic species of Yunnan represent a mixture of neoendemics and paleoendemics. The formation of patterns of endemism in Cyclobalanopsis is due primarily to geographical isolation and the complex history of climatic and geological changes. Also we have discussed vicariance of Cyclobalanopsis: Q.glauca & Q.schottkyana, Q.gilva & Q.delavayi, Q.sessifolia & Q.augustinii are vicariance species between Sino-Japan and Sino-Himalaya.%对壳斗科青冈亚属(Quercussubg.Cyclobalanopsis)植物分布区内各地区的分布作了分析和统计。通过分析,认为中国南部、西南部和中南半岛北部,即印度支那植物地区,是青冈亚属植物地理分布的分布区中心。基于其形态、现代分布和地史资料,马来西亚地区分布有许多性状较原始的类群,是青冈亚属原始类群的保存中心。青冈亚属植物中有许多地区性特有种,它们的分布区很狭窄,集中分布在加里曼丹、台湾、海南和云南东南部,其产生的原因主要是地理隔离,如海峡、高山等,

  10. MASA TOTAL Y CONTENIDO DE NUTRIENTES EN RAÍCES FINAS DE ECOSISTEMAS FORESTALES (Pinus patula Schltdl y Cham Cupressus lusitanica Mill y Quercus humboldtii Bonpl.) DE PIEDRAS BLANCAS, ANTIOQUIA-COLOMBIA TOTAL FINE ROOT MASS AND NUTRIENT CONTENT IN FOREST ECOSYSTEMS (Pinus patula Schltdl and Cham Cupressus lusitanica Mill and Quercus humboldtii Bonpl.) FROM PIEDRAS BLANCAS, ANTIOQUIA-COLOMBIA

    OpenAIRE

    2005-01-01

    En la región de Piedras Blancas, Antioquia - Colombia, se realizó un muestreo de raíces finas (£ 5 mm) en tres parcelas permanentes establecidas en bosques de pino pátula (Pinus patula Schltdl y Cham), ciprés (Cupressus lusitanica Mill) y roble (Quercus humboldtii Bonpl.) a diferentes profundidades: 0-30, 30-50 y 50- 80 cm, con el fin de determinar la masa de raíces, y la concentración y contenido de nutrientes en cada cobertura vegetal. La masa de raíces finas disminuyó rápidamente a medida ...

  11. Análisis espacio-temporal de los vasos primaverales de Quercus robur L. y Quercus pyrenaica Willd.: Respuesta al estrés climático en la transición atlántico-mediterránea

    OpenAIRE

    Souto Herrero, Manuel

    2016-01-01

    En esta Tesis Doctoral se estudiaron los elementos conductores primaverales de Quercus robur L. y Q. pyrenaica Willd. con el objetivo de valorar su potencial dendroecológico. Mediante su empleo se trató de identificar los factores climáticos más relevantes que controlan el crecimiento en la transición entre las regiones biogeográficas atlántica y mediterránea en el noroeste de la Península Ibérica. Para abordar este trabajo se aplicaron técnicas dendrocronológicas tales como la medición de la...

  12. <em>In Vitro em>and <em>in em>Vivo> Antitumor Effect of Trachylobane-360, a Diterpene from<em> Xylopia langsdorffianaem>

    Directory of Open Access Journals (Sweden)

    João Carlos Lima Rodrigues Pita

    2012-08-01

    Full Text Available Trachylobane-360 (<em>ent>-7α-acetoxytrachyloban-18-oic acid was isolated from <em>Xylopia langsdorffianaem>. Studies have shown that it has weak cytotoxic activity against tumor and non-tumor cells. This study investigated the <em>in vitroem>> em>and <em>in vivoem> antitumor effects of trachylobane-360, as well as its cytotoxicity in mouse erythrocytes. In order to evaluate the <em>in vivoem> toxicological aspects related to trachylobane-360 administration, hematological, biochemical and histopathological analyses of the treated animals were performed. The compound exhibited a concentration-dependent effect in inducing hemolysis with HC50 of 273.6 µM, and a moderate <em>in vitroem>> em>concentration-dependent inhibitory effect on the proliferation of sarcoma 180 cells with IC50 values of 150.8 µM and 150.4 µM, evaluated by the trypan blue exclusion test and MTT reduction assay, respectively. The <em>in vivoem> inhibition rates of sarcoma 180 tumor development were 45.60, 71.99 and 80.06% at doses of 12.5 and 25 mg/kg of trachylobane-360 and 25 mg/kg of 5-FU, respectively. Biochemical parameters were not altered. Leukopenia was observed after 5-FU treatment, but this effect was not seen with trachylobane-360 treatment. The histopathological analysis of liver and kidney showed that both organs were mildly affected by trachylobane-360 treatment. Trachylobane-360 showed no immunosuppressive effect. In conclusion, these data reinforce the anticancer potential of this natural diterpene.

  13. Purification, Characterization and Antioxidant Activities <em>in Vitroem>> em>and <em>in Vivoem> of the Polysaccharides from <em>Boletus edulisem> Bull

    Directory of Open Access Journals (Sweden)

    Yijun Fan

    2012-07-01

    Full Text Available A water-soluble polysaccharide (BEBP was extracted from <em>Boletus edulis em>Bull using hot water extraction followed by ethanol precipitation. The polysaccharide BEBP was further purified by chromatography on a DEAE-cellulose column, giving three major polysaccharide fractions termed BEBP-1, BEBP-2 and BEBP-3. In the next experiment, the average molecular weight (Mw, IR and monosaccharide compositional analysis of the three polysaccharide fractions were determined. The evaluation of antioxidant activities both <em>in vitroem> and <em>in vivo em>suggested that BEBP-3 had good potential antioxidant activity, and should be explored as a novel potential antioxidant.

  14. PRODUCCIÓN Y ALMACENAMIENTO DE BELLOTAS DE QUERCUS HINTONII WARBURG (FAGACEAE) DE LA DEPRESIÓN DEL BALSAS, MÉXICO

    OpenAIRE

    David Díaz-Pontones; Irma Reyes-Jaramillo

    2009-01-01

    México es un centro de diversificación de encinos que cubren gran parte de las zonas montañosas del país con gran número de especies endémicas, entre ellas Quercus hintonii Warburg, especie de encino rojo, amenazada por la tala clandestina y cambio de uso del suelo. Se distribuye en el SW del Estado de México dentro del sistema orográfi co de la provincia de la Sierra Madre del Sur, subprovincia de la Depresión del Balsas. El presente estudio aporta información de la producción de su bellota ...

  15. Variation of Oriental Oak (Quercus variabilis Leaf δ13C across Temperate and Subtropical China: Spatial Patterns and Sensitivity to Precipitation

    Directory of Open Access Journals (Sweden)

    Baoming Du

    2015-06-01

    Full Text Available The concentration of the carbon-13 isotope (leaf δ13C in leaves is negatively correlated with the mean annual precipitation (MAP atlarge geographical scales. In this paper, we explain the spatial pattern of leaf δ13C variation for deciduous oriental oak (Quercus variabilis Bl. across temperate and subtropical biomes and its sensitivity to climate factors such as MAP. There was a 6‰ variation in the leaf δ13C values of oak with a significant positive correlation with latitude and negative correlations with the mean annual temperature (MAT and MAP. There was no correlation between leaf δ13C and altitude or longitude. Stepwise multiple regression analyses showed that leaf δ13C decreased 0.3‰ per 100 mm increase in MAP. MAP alone could account for 68% of the observed variation in leaf δ13C. These results can be used to improve predictions for plant responses to climate change and particularly lower rainfall.

  16. Glycosylation of Vanillin and 8-Nordihydrocapsaicin by Cultured <em>Eucalyptus perrinianaem> Cells

    Directory of Open Access Journals (Sweden)

    Naoji Kubota

    2012-05-01

    Full Text Available Glycosylation of vanilloids such as vanillin and 8-nordihydrocapsaicin by cultured plant cells of <em>Eucalyptus perrinianaem> was studied. Vanillin was converted into vanillin 4-<em>O>-b-D-glucopyranoside, vanillyl alcohol, and 4-<em>O>-b-D-glucopyranosylvanillyl alcohol by <em>E. perriniana em>cells. Incubation of cultured <em>E. perrinianaem> cells with 8-nor- dihydrocapsaicin gave 8-nordihydrocapsaicin 4-<em>O>-b-D-glucopyranoside and 8-nordihydro- capsaicin 4-<em>O>-b-D-gentiobioside.

  17. A specimen of <em>Sorex> cfr. <em>samniticus> in Barn Owl's pellets from Murge plateau (Apulia, Italy / Su di un <em>Sorex> cfr. <em>samniticus> (Insectivora, Soricidae rinvenuto in borre di <em>Tyto albaem> delle Murge (Puglia, Italia

    Directory of Open Access Journals (Sweden)

    Giovanni Ferrara

    1992-07-01

    Full Text Available Abstract In a lot of Barn Owl's pellets from the Murge plateau a specimen of <em>Sorex> sp. was detected. Thank to some morphological and morphometrical features, the cranial bones can be tentatively attributed to <em>Sorex samniticusem> Altobello, 1926. The genus <em>Sorex> was not yet included in the Apulia's fauna southwards of the Gargano district; the origin and significance of the above record is briefly discussed, the actual presence of a natural population of <em>Sorex> in the Murge being not yet proved. Riassunto Viene segnalato il rinvenimento di un esemplare di <em>Sorex> cfr. <em>samniticus> da borre di <em>Tyto albaem> delle Murge. Poiché il genere non era stato ancora segnalato nella Puglia a sud del Gargano, viene discusso il significato faunistico del reperto.

  18. Alteration of foliar flavonoid chemistry induced by enhanced UV-B radiation in field-grown Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii.

    Science.gov (United States)

    Warren, Jeffrey M; Bassman, John H; Mattinson, D Scott; Fellman, John K; Edwards, Gerald E; Robberecht, Ronald

    2002-03-01

    Chromatographic analyses of foliage from several tree species illustrate the species-specific effects of UV-B radiation on both quantity and composition of foliar flavonoids. Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii were field-grown under modulated ambient (1x) and enhanced (2x) biologically effective UV-B radiation. Foliage was harvested seasonally over a 3-year period, extracted, purified and the flavonoid fraction applied to a mu Bondapak/C(18) column HPLC system sampling at 254 nm. Total flavonoid concentrations in Quercus rubra foliage were more than twice (leaf area basis) that of the other species; Pseudotsuga menziesii foliage had intermediate levels and P. ponderosa had the lowest concentrations of total flavonoids. No statistically significant UV-B radiation-induced effects were found in total foliar flavonoid concentrations for any species; however, concentrations of specific compounds within each species exhibited significant treatment effects. Higher (but statistically insignificant) levels of flavonoids were induced by UV-B irradiation in 1- and 2-year-old P. ponderosa foliage. Total flavonoid concentrations in 2-year-old needles increased by 50% (1x ambient UV-B radiation) or 70% (2x ambient UV-B radiation) from that of 1-year-old tissue. Foliar flavonoids of Q. rubra under enhanced UV-B radiation tended to shift from early-eluting compounds to less polar flavonoids eluting later. There were no clear patterns of UV-B radiation effects on 1-year-old P. menziesii foliage. However, 2-year-old tissue had slightly higher foliar flavonoids under the 2x UV-B radiation treatment compared to ambient levels. Results suggest that enhanced UV-B radiation will alter foliar flavonoid composition and concentrations in forest tree species, which could impact tissue protection, and ultimately, competition, herbivory or litter decomposition.

  19. Population-Level Differentiation in Growth Rates and Leaf Traits in Seedlings of the Neotropical Live Oak Quercus oleoides Grown under Natural and Manipulated Precipitation Regimes

    Directory of Open Access Journals (Sweden)

    Jose A. Ramírez-Valiente

    2017-05-01

    Full Text Available Widely distributed species are normally subjected to spatial heterogeneity in environmental conditions. In sessile organisms like plants, adaptive evolution and phenotypic plasticity of key functional traits are the main mechanisms through which species can respond to environmental heterogeneity and climate change. While extended research has been carried out in temperate species in this regard, there is still limited knowledge as to how species from seasonally-dry tropical climates respond to spatial and temporal variation in environmental conditions. In fact, studies of intraspecific genetically-based differences in functional traits are still largely unknown and studies in these ecosystems have largely focused on in situ comparisons where environmental and genetic effects cannot be differentiated. In this study, we tested for ecotypic differentiation and phenotypic plasticity in leaf economics spectrum (LES traits, water use efficiency and growth rates under natural and manipulated precipitation regimes in a common garden experiment where seedlings of eight populations of the neotropical live oak Quercus oleoides were established. We also examined the extent to which intraspecific trait variation was associated with plant performance under different water availability. Similar to interspecific patterns among seasonally-dry tropical tree species, live oak populations with long and severe dry seasons had higher leaf nitrogen content and growth rates than mesic populations, which is consistent with a “fast” resource-acquisition strategy aimed to maximize carbon uptake during the wet season. Specific leaf area (SLA was the best predictor of plant performance, but contrary to expectations, it was negatively associated with relative and absolute growth rates. This observation was partially explained by the negative association between SLA and area-based photosynthetic rates, which is contrary to LES expectations but similar to other recent

  20. Population-Level Differentiation in Growth Rates and Leaf Traits in Seedlings of the Neotropical Live Oak Quercus oleoides Grown under Natural and Manipulated Precipitation Regimes.

    Science.gov (United States)

    Ramírez-Valiente, Jose A; Center, Alyson; Sparks, Jed P; Sparks, Kimberlee L; Etterson, Julie R; Longwell, Timothy; Pilz, George; Cavender-Bares, Jeannine

    2017-01-01

    Widely distributed species are normally subjected to spatial heterogeneity in environmental conditions. In sessile organisms like plants, adaptive evolution and phenotypic plasticity of key functional traits are the main mechanisms through which species can respond to environmental heterogeneity and climate change. While extended research has been carried out in temperate species in this regard, there is still limited knowledge as to how species from seasonally-dry tropical climates respond to spatial and temporal variation in environmental conditions. In fact, studies of intraspecific genetically-based differences in functional traits are still largely unknown and studies in these ecosystems have largely focused on in situ comparisons where environmental and genetic effects cannot be differentiated. In this study, we tested for ecotypic differentiation and phenotypic plasticity in leaf economics spectrum (LES) traits, water use efficiency and growth rates under natural and manipulated precipitation regimes in a common garden experiment where seedlings of eight populations of the neotropical live oak Quercus oleoides were established. We also examined the extent to which intraspecific trait variation was associated with plant performance under different water availability. Similar to interspecific patterns among seasonally-dry tropical tree species, live oak populations with long and severe dry seasons had higher leaf nitrogen content and growth rates than mesic populations, which is consistent with a "fast" resource-acquisition strategy aimed to maximize carbon uptake during the wet season. Specific leaf area (SLA) was the best predictor of plant performance, but contrary to expectations, it was negatively associated with relative and absolute growth rates. This observation was partially explained by the negative association between SLA and area-based photosynthetic rates, which is contrary to LES expectations but similar to other recent intraspecific studies on

  1. Study of the <em>in Vitroem> Antiplasmodial, Antileishmanial and Antitrypanosomal Activities of Medicinal Plants from Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Nawal M. Al-Musayeib

    2012-09-01

    Full Text Available The present study investigated the <em>in vitroem> antiprotozoal activity of sixteen selected medicinal plants. Plant materials were extracted with methanol and screened <em>in vitroem> against erythrocytic schizonts of <em>Plasmodium falciparumem>, intracellular amastigotes of <em>Leishmania infantum em>and <em>Trypanosoma cruzi em>and free trypomastigotes of<em> T. bruceiem>. Cytotoxic activity was determined against MRC-5 cells to assess selectivity<em>. em>The criterion for activity was an IC50 < 10 µg/mL (4. Antiplasmodial activity was found in the<em> em>extracts of<em> em>>Prosopis julifloraem> and <em>Punica granatumem>. Antileishmanial activity<em> em>against <em>L. infantumem> was demonstrated in <em>Caralluma sinaicaem> and <em>Periploca aphylla.em> Amastigotes of<em> T. cruzi em>were affected by the methanol extract of<em> em>>Albizia lebbeckem>> em>pericarp, <em>Caralluma sinaicaem>,> Periploca aphylla em>and <em>Prosopius julifloraem>. Activity against<em> T. brucei em>was obtained in<em> em>>Prosopis julifloraem>. Cytotoxicity (MRC-5 IC50 < 10 µg/mL and hence non-specific activities were observed for<em> em>>Conocarpus lancifoliusem>.>

  2. EMS in Mauritius.

    Science.gov (United States)

    Ramalanjaona, Georges; Brogan, Gerald X

    2009-02-01

    Mauritius lies in the southwest Indian Ocean about 1250 miles from the African coast and 500 miles from Madagascar. Mauritius (estimated population 1,230,602) became independent from the United Kingdom in 1968 and has one of the highest GDP per capita in Africa. Within Mauritius there is a well established EMS system with a single 999 national dispatch system. Ambulances are either publicly or privately owned. Public ambulances are run by the Government (SAMU). Megacare is a private subscriber only ambulance service. The Government has recently invested in new technology such as telemedicine to further enhance the role of EMS on the island. This article describes the current state of EMS in Mauritius and depicts its development in the context of Government effort to decentralise and modernise the healthcare system.

  3. Spatial and temporal variations of soil moisture under Rosmarinus officinalis and Quercus coccifera in a burned soil

    Science.gov (United States)

    Gimeno-García, E.; Pascual-Aguilar, J. A.; Llovet, J.

    2009-04-01

    When studying surface runoff processes, measurement of the soil moisture content (SMC) at the surface could be used to identify sinks and sources areas of runoff. Surface soil moisture patterns variability have been studied in a burned Mediterranean semi-arid area. Since surface SMC and soil water repellency (SWR) are influenced by fire and vegetation (see previous abstract), and soil water dynamics and vegetation dynamics are functionally related, it could be expected to find some changes during the following months after fire when vegetation starts to recover. The identification of these changes is the main goal of this research. The study area is located at the municipality of Les Useres, 40 km from Castellón city (E Spain), where a wildfire occured in August 2007. We selected a burned SSE facing hillslope, located at 570 m a.s.l., with 12° slope angle, in which it was possible to identify the presence of two unique shrub species: Quercus coccifera L. and Rosmarinus officinalis L., which were distributed in a patchy mosaic. Twenty microsites with burned R. officinalis and eight microsites with burned Q. coccifera were selected in an area of 7 m wide by 14 m long. At the burned microsites, it was possible to distinguish three concentric zones (I, II and III) around the stumps showing differences on their soil surface appearance, which indicate a gradient of fire severity. Those differences were considered for field soil moisture measurements. Five measurements of SMC separated approximately 10 cm per zone at each microsite (n= 420) were carried out after different rainfall events. Volumetric soil moisture was measured by means of the moisture meter HH2 with ThetaProbe sensor type ML2x, 6 cm long. SMC was monitored on three occasions, always one day after the following rainfall events: (1) the first rainfall event after fire, when 11 mm were registered (Oct-07); (2) four months later than fire (Dec-07), after six consecutive raining days with a total rain volume

  4. Acidose ruminal em caprinos

    OpenAIRE

    Cunha, José Diogo de Oliveira e silva Ribeiro da

    2012-01-01

    Dissertação de Mestrado Integrado em Medicina Veterinária Com este trabalho pretendeu-se fazer uma revisão acerca da acidose ruminal em caprinos, visto haver pouca bibliografia sobre o tema. Este trabalho foi baseado na revisão bibliográfica de artigos científicos e completado através da observação de casos clínicos ocorridos durante o estágio curricular. O objectivo deste estudo foi realizar uma breve revisão da anatomia e fisiologia do tracto gastrointestinal dos caprinos assim com...

  5. Ulisses em Kafka

    Directory of Open Access Journals (Sweden)

    Stéphane Mosès

    2015-02-01

    Full Text Available ResumoEm sua introdução para Exegese de uma lenda, Stéphane Mosès afirma que a obra de Kafka não necessita de novas interpretações, mas sim de uma “análise rigorosa de sua lógica subjacente”. Assim, em “Ulisses em Kafka”, investigandoa dialética formal de “O silêncio das sereias”, Mosès procura expor a estrutura narrativa que comandaria esse breve texto em que o escritor tcheco acrescenta à astucia de Ulisses a ingenuidade como elemento de salvação.Palavras-chave: Kafka; dialética; salvação.AbstractIn his introduction to Exegèse d’une légende, Stéphane Mosès affirms that Kafka’s works are not in need of new interpretations, but rather, of a “rigorous analysis of their underlying logic”. Thus, in “Ulisses chez Kafka”, by investigating the formal dialectic of “Das Schweigen der Sirenen”, Mosès seeks to exhibit the narrative structure that would supposedly guide this short text in which the Czech author adds naïveté to Ulisses’s cunning intelligence as an element of salvation.Keywords: Kafka; dialectic; salvation.Stéphane Mosès foi professor emérito da Universidade Hebraica de Jerusalém, onde ensinou Literatura Alemã e Comparada, entre os seus principais interesses estavam o pensamento de Franz Rosenzweig e de Walter Benjamin e as literaturas de Franz Kafka e de Paul Célan. Autor de diversos livros, entre eles: L'ange de l'histoire. Rosenzweig, Benjamin, Scholem, Exégèse d'une légende, lectures de Kafka, e Rêves de Freud. Six lectures.Rodrigo Ielpo é doutor em literatura francesa pela UFRJ e em História e Semiologia do texto e da imagem pela Université Paris VII, com pós-doutorado em Teoria Literária pela UNICAMP. Professor Adjunto do Departamento de Letras Neolatinas da Universidade Federal do Rio de Janeiro, possui publicações e traduções nos seguintes temas: teoria e literatura francesa contemporâneas, escrita e processos de subjetivação.rodrigoielpo@gmail.com 

  6. International EMS Systems

    DEFF Research Database (Denmark)

    Langhelle, Audun; Lossius, Hans Morten; Silfvast, Tom

    2004-01-01

    exist, however, especially within the ground and air ambulance service, and the EMS systems face several challenges. Main problems and challenges emphasized by the authors are: (1) Denmark: the dispatch centres are presently not under medical control and are without a national criteria based system......Emergency medicine service (EMS) systems in the five Nordic countries have more similarities than differences. One similarity is the involvement of anaesthesiologists as pre-hospital physicians and their strong participation for all critically ill and injured patients in-hospital. Discrepancies do...

  7. Frenectomia em foco

    OpenAIRE

    Vieira, Joana Isabel Monteiro de Paiva

    2012-01-01

    Projeto de Pós Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária O freio é uma estrutura anatómica oral classificada em freio labial (médio maxilar ou mandibular, lateral maxilar ou mandibular) ou lingual que se pode tornar num problema quando a sua inserção cria impedimentos estruturais e dificuldades a vários níveis. Um freio labial anormal pode causar algumas anomalias ou problemas, tais como u...

  8. Cyberbullying em adolescentes brasileiros

    OpenAIRE

    Wendt, Guilherme Welter

    2012-01-01

    O cyberbullying é entendido como uma forma de comportamento agressivo que ocorre através dos meios eletrônicos de interação (computadores, celulares, sites de relacionamento virtual), sendo realizado de maneira intencional por uma pessoa ou grupo contra alguém em situação desigual de poder e, ainda, com dificuldade em se defender. Os estudos disponíveis até o presente momento destacam que o cyberbullying é um fator de risco para o desenvolvimento de sintomas de ansiedade, depressão, ideação s...

  9. Corantes vitais em cromovitrectomia

    OpenAIRE

    Dib, Eduardo; Rodrigues,Eduardo Büchelle; Maia, Maurício [UNIFESP; Meyer, Carsten H; Penha, Fernando Marcondes [UNIFESP; Furlani, Bruno de Albuquerque [UNIFESP; Costa, Elaine de Paula Fiod [UNIFESP; Farah, Michel Eid

    2009-01-01

    O objetivo do artigo é apresentar os dados atuais da aplicação de corantes vitais durante cirurgia vitreorretiniana, "cromovitrectomia", bem como uma revisão da literatura atual sobre o assunto no tocante às técnicas de aplicação, indicações e complicações em cromovitrectomia. Um grande número de publicações tem abordado o perfil tóxico da indocianina verde na cromovitrectomia. Dados experimentais mostram uma toxicidade dose-dependente da mesma em várias populações de células retinianas. Nova...

  10. O recasamento em Portugal

    OpenAIRE

    Lobo, Cristina; Conceição, Cristina Palma

    2003-01-01

    Identificar tendências do fenómeno do recasamento em Portugal, nas duas últimas décadas, constitui o objectivo principal deste artigo. Para essa identificação contribuiu o conhecimento da amplitude do próprio fenómeno, isto é, a percentagem de recasamentos no total dos casamentos em Portugal, e ainda um conjunto de variáveis que permitiu conhecer a caracterização social dos protagonistas do recasamento, por um lado, e delinear a diversidade dos seus trajectos conjugais após um divórcio, por o...

  11. Frenectomia em foco

    OpenAIRE

    Vieira, Joana Isabel Monteiro de Paiva

    2012-01-01

    Projeto de Pós Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária O freio é uma estrutura anatómica oral classificada em freio labial (médio maxilar ou mandibular, lateral maxilar ou mandibular) ou lingual que se pode tornar num problema quando a sua inserção cria impedimentos estruturais e dificuldades a vários níveis. Um freio labial anormal pode causar algumas anomalias ou problemas, tais como u...

  12. Acidose ruminal em caprinos

    OpenAIRE

    Cunha, José Diogo de Oliveira e silva Ribeiro da

    2012-01-01

    Dissertação de Mestrado Integrado em Medicina Veterinária Com este trabalho pretendeu-se fazer uma revisão acerca da acidose ruminal em caprinos, visto haver pouca bibliografia sobre o tema. Este trabalho foi baseado na revisão bibliográfica de artigos científicos e completado através da observação de casos clínicos ocorridos durante o estágio curricular. O objectivo deste estudo foi realizar uma breve revisão da anatomia e fisiologia do tracto gastrointestinal dos caprinos assim com...

  13. Horizontal Transmission of the Entomopathogen Fungus <em>Metarhizium anisopliae em>in <em>Microcerotermes diversusem> Groups

    Directory of Open Access Journals (Sweden)

    Mohammad Saied Mossadegh

    2012-08-01

    Full Text Available An experiment was carried out in order to investigate fungal conidia transmission of <em>Metarhizium anisopliae em>(Metschnikoff> em>Sorokin from vector (donor to healthy <em>Microcerotermes diversusem> Silvestri (Iso.: Termitidae and determine the best donor/concentration ratio for transmission. After preliminary trials, concentrations of 3.1 × 104, 3.9 × 105, 3.2 × 106 and 3.5 × 108 conidia mL−1 were selected for testing. The experiment was performed at three donor : Recipient ratios of 10, 30 and 50%. The highest mortality of recipient workers was observed after 14 days at the concentration of 3.5 × 108 conidia mL−1 and donor ratio of 50%. The mortality of recipient workers was less than 20% at all concentrations at a donor ratio of 10%. Our observations indicate social behavior of <em>M. diversusem>, such as grooming, can be effective in promoting epizootic outbreaks in a colony. While the current results suggest good potential for efficacy, the use of <em>M. anisopliaeem> as a component of integrated pest management of <em>M. diversusem> still needs to be proven under field conditions.

  14. Clinical Relevance of <em>CDH1em> and <em>CDH13em> DNA-Methylation in Serum of Cervical Cancer Patients

    Directory of Open Access Journals (Sweden)

    Günther K. Bonn

    2012-07-01

    Full Text Available This study was designed to investigate the DNA-methylation status of <em>E>-cadherin (<em>CDH1em> and <em>H>-cadherin (<em>CDH13em> in serum samples of cervical cancer patients and control patients with no malignant diseases and to evaluate the clinical utility of these markers. DNA-methylation status of <em>CDH1em> and <em>CDH13em> was analyzed by means of MethyLight-technology in serum samples from 49 cervical cancer patients and 40 patients with diseases other than cancer. To compare this methylation analysis with another technique, we analyzed the samples with a denaturing high performance liquid chromatography (DHPLC PCR-method. The specificity and sensitivity of <em>CDH1em> DNA-methylation measured by MethyLight was 75% and 55%, and for <em>CDH13em> DNA-methylation 95% and 10%. We identified a specificity of 92.5% and a sensitivity of only 27% for the <em>CDH1em> DHPLC-PCR analysis. Multivariate analysis showed that serum <em>CDH1em> methylation-positive patients had a 7.8-fold risk for death (95% CI: 2.2–27.7; <em>p> = 0.001 and a 92.8-fold risk for relapse (95% CI: 3.9–2207.1; <em>p> = 0.005. We concluded that the serological detection of <em>CDH1em> and <em>CDH13em> DNA-hypermethylation is not an ideal diagnostic tool due to low diagnostic specificity and sensitivity. However, it was validated that <em>CDH1em> methylation analysis in serum samples may be of potential use as a prognostic marker for cervical cancer patients.

  15. Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners.

    Science.gov (United States)

    Kim, Wanggyu; Yukawa, Junichi; Harris, Keith M; Minami, Tsuneo; Matsuo, Kazunori; Skrzypczyńska, Małgorzata

    2014-06-20

    A gall midge that induces upwardly folded leaf-margin galls on Quercus serrata, Q. mongolica and Q. dentata (Fagaceae) in Japan and South Korea is described as Macrodiplosis selenis sp. n. (Diptera: Cecidomyiidae). M. selenis is distinguished from Palaearctic congeners by a combination of morphological characters. Genetic differences supported the result of morphological comparison and indicated that M. selenis is closely related to the European M. roboris, whose gall is similar to that of M. selenis.

  16. Time-Dependent Damage Investigation of Rock Mass in an <em>In> em>Situ> Experimental Tunnel

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2012-08-01

    Full Text Available In underground tunnels or caverns, time-dependent deformation or failure of rock mass, such as extending cracks, gradual rock falls, <em>etc>., are a costly irritant and a major safety concern if the time-dependent damage of surrounding rock is serious. To understand the damage evolution of rock mass in underground engineering, an <em>in situem> experimental testing was carried out in a large belowground tunnel with a scale of 28.5 m in width, 21 m in height and 352 m in length. The time-dependent damage of rock mass was detected in succession by an ultrasonic wave test after excavation. The testing results showed that the time-dependent damage of rock mass could last a long time, <em>i.e.>, nearly 30 days. Regression analysis of damage factors defined by wave velocity, resulted in the time-dependent evolutional damage equation of rock mass, which corresponded with logarithmic format. A damage viscoelastic-plastic model was developed to describe the exposed time-dependent deterioration of rock mass by field test, such as convergence of time-dependent damage, deterioration of elastic modules and logarithmic format of damage factor. Furthermore, the remedial measures for damaged surrounding rock were discussed based on the measured results and the conception of damage compensation, which provides new clues for underground engineering design.

  17. Ultrasound-Assisted Extraction of Syringin from the Bark of <em>Ilex em>rotunda> Thumb Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2012-06-01

    Full Text Available In this work, a rapid extraction method based on ultrasound-assisted extraction (UAE of syringin from the bark of <em>Ilex rotunda em>Thumb using response surface methodology (RSM is described. The syringin was analyzed and quantified by high performance liquid chromatography coupled with UV detection (HPLC-UV. The extraction solvent, extraction temperature and extraction time, the three main factors for UAE, were optimized with Box-Behnken design (BBD to obtain the highest extraction efficiency. The optimal conditions were the use of a sonication frequency of 40 kHz, 65% methanol as the solvent, an extraction time of 30 min and an extraction temperature of 40 °C. Using these optimal conditions, the experimental values agreed closely with the predicted values. The analysis of variance (ANOVA indicated a high goodness of model fit and the success of the RSM method for optimizing syringin extraction from the bark of <em>I>. em>rotunda>.

  18. 栓皮栎体细胞胚胎发生的细胞组织学观察%Histological Observation of Somatic Embryogenesis from Cultured Embryos of Quercus variabilis BI.

    Institute of Scientific and Technical Information of China (English)

    张存旭; 姚增玉; 赵忠; 戚建华

    2007-01-01

    以栓皮栎未成熟合子胚为外植体,在添加0.25mg/L 2,4-D和0.5 mg/L 6-BA的MS培养基上6周可诱导产生2种类型的胚性愈伤组织,一种表面具光泽、白色;另一种表面光滑湿润具光泽,色泽淡黄或无色透明.组织切片表明,胚性愈伤组织的细胞体积小,细胞核大,细胞质浓,细胞排列紧密;非胚性愈伤组织细胞的体积大,细胞核小,细胞质稀薄.胚性细胞团培养在不含激素的培养基上可诱导产生体细胞胚.体细胞胚直接起源于胚性细胞团表皮或近表皮的单细胞,经历与合子胚相似的球形胚、心形胚、鱼雷胚和子叶胚发育阶段.所有发育时期的体细胞胚的胚轴、子叶均产生次生体胚,它们起源于细胞质较浓的表皮单细胞.%Immature zygotic embryos of Quercus variabilis B1.were excised and cultured on MS basal medium containing 0.25 mg/L 2,4-dichlorophenoxyacetic acid and 0.5 mg/L 6-benzyl aminopurine.Callus was initiated from these embryos within 6 weeks.Two types of embryogenic calluses were formed:one was the white mucilaginous callus and the other was light yellow to translucent,glossy,mucilaginous.Histological examination showed that the non-embryogenic cells derived from zygotic embryos were large in size,with small nuclei,thin cytoplasm,and the embryogenic cells were small in size,with large nuclei,thick cytoplasm and denser arrangement.Somatic embryos were induced from embryogenic masses(EMS)cultured on a medium not containing plant growth regulators(PGRs).The histological origin of somatic embryos was single epidermal or subepidermal cells.Somatic embryos displayed a standard development pattern,from globular ones to heartlike and torpedo-shaped ones and finally to embryo with two cotyledons,which was similar to the development of zygotic embryo in vivo.Secondary proembryos were formed on the axis and cotyledon of existing embryos and originated from single,densely stained cells of the epidermis at all stages.

  19. Carbon transfer from photosynthesis to below ground fine root/hyphae respiration in Quercus serrata using stable carbon isotope pulse labeling

    Science.gov (United States)

    Dannoura, M.; Kominami, Y.; Takanashi, S.; Takahashi, K.

    2013-12-01

    Studying carbon allocation in trees is a key to better understand belowground carbon cycle and its response to climate change. Tracing 13C in tree and soil compartments after pulse labeling is one of powerful tool to study the fate of carbon in forest ecosystems. This experiment was conducted in Yamashiro experimental forest, Kyoto, Japan. Annual mean temperature and precipitation from 1994 to 2009 are 15.5 ° C and 1,388 mm respectively. The branch pulse labeling were done 7 times in 2011 using same branch of Quercus serrata (H:11.7 m, DBH; 33.7 cm) to see seasonal variations of carbon velocity. Whole crown labeling of Quercus serrata (H:9 m, DBH; 13.7 cm) was done in 2012 to study carbon allocation and to especially focus on belowground carbon flux until to the hyphae respiration. Pure 13CO2 (99.9%) was injected to the labeling chamber which was set to branch or crown. Then, after one hour of branch labeling and 3.5 hour for crown labeling, the chamber was opened. Trunk respiration chambers, fine root chambers and hyphae chambers were set to the target tree to trace labeled carbon in the CO2 efflux. 41 μm mesh was used to exclude ingrowth of roots into hyphae chambers. The results show that the velocity of carbon through the tree varied seasonally, with higher velocity in summer than autumn, averaging 0.47 m h-1. Half-lives of labeled carbon in autotrophic respiration were similar above and below ground during the growing season, but they were twice longer in trunk than in root in autumn. From the whole crown labeling done end of growing season, the 13CO2 signal was observed 25 hours after labeling in trunk chamber and 34-37.7 hours after labeling in fine root and hyphae respiration almost simultaneously. Half-lives of 13 was longer in trunk than below ground. Trunk respiration was still using labelled carbon during winter suggesting that winter trunk respiration is partly fueled by carbon stored in the trunk at the end of the growing season.

  20. Classe social: conceitos e esquemas operacionais em pesquisa em saude

    Directory of Open Access Journals (Sweden)

    Rita Barradas Barata

    2013-08-01

    Full Text Available Discute-se a utilização do conceito de classe em pesquisas em saúde, as diferentes abordagens sociológicas de estratificação social e de estrutura de classes, o potencial explicativo do conceito em estudos de determinação social e desigualdades em saúde, os modelos de operacionalização elaborados para uso em pesquisas sociológicas, demográficas ou de saúde e os limites e possibilidades desses modelos. Foram destacados quatro modelos de operacionalização: de Singer para estudo da distribuição de renda no Brasil, adaptado por Barros para uso em pesquisas epidemiológicas; de Bronfman & Tuirán para o censo demográfico mexicano, adaptado por Lombardi et al para pesquisas epidemiológicas; de Goldthorpe para estudos socioeconômicos ingleses, adaptado pela Sociedade Espanhola de Epidemiologia; e o modelo de Wright para pesquisa em sociologia e ciência política, também usado em inquéritos populacionais em saúde. Em conclusão, conceitualmente cada um dos modelos apresentados é coerente com a concepção teórica que os embasam, mas não há como optar por qualquer deles, descartando os demais.