WorldWideScience

Sample records for growth factor-affinity-labeled species

  1. Emergence and seedling growth of five forage legume species at ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... Seed characteristics of legume species used in this study. Species. Cultivar. Collect location. Seed mass (mg). T. repens. -. Jilin Province. 0.58±0.002 .... The effects of depth (D), light (L), species (S) and their interaction on germination characteristics, morphological ..... Early seedling growth of pine (Pinus.

  2. Experiments on growth interactions between two invasive macrophyte species

    NARCIS (Netherlands)

    Barrat-Segretain, M-H.; Elger, A.F.

    2004-01-01

    The success of invasive species has been attributed to the ability to displace other species by direct competition. We studied growth and possible competition between the two macrophyte species Elodea nuttallii and E. canadensis, because the former has been observed to replace the latter in the

  3. FEM growth and yield data monocultures - other species

    NARCIS (Netherlands)

    Goudzwaard, L.; Jansen, J.J.; Oosterbaan, A.; Oldenburger, J.F.; Mohren, G.M.J.; Ouden, den J.

    2016-01-01

    The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,

  4. Comparative growth performance of different Casuarina species and ...

    African Journals Online (AJOL)

    Variation in growth charactristics, coppicing ability and understory vegetation development was assessed in four Casuarina species (C. equisetifolia, C. junghuhniana, C. cunnighamiana and C. oligodon) grown in Lushoto in the West Usambara Mountains (WUM), Tanzania. The performance of the four species as well as of ...

  5. The growth performance of exotic and indigenous tree species in ...

    African Journals Online (AJOL)

    The saplings were monitored for survival rates one year after transplanting and growth performances by measuring root collar diameters and heights. There was no significant difference among the species in survival. The mean height increment of the exotics significantly surpassed indigenous tree species. E. grandis ...

  6. Species Diversity and Growth Forms in Tropical American Palm Communities

    DEFF Research Database (Denmark)

    Balslev, Henrik; Kahn, Francis; Millán, Betty

    2011-01-01

    To advance our understanding of the processes that govern the assembly of palm communities and the local coexistence of numerous palm species, we here synthesize available information in the literature on species diversity and growth-form composition in palm communities across the Americas....... American palm communities surveyed had 4–48 (median 16) species in study plots covering 0.09–7.2 ha. Climate, soils, hydrology, and topography are the main factors determining palm community species richness. Tropical lowland terra firme rain forests are the most species-rich whereas forests...... that are inundated or grow on sandy soils or in areas with seasonal climate have much fewer species. Palm communities in the central-western Amazon and in Central America are significantly richer than the average region and those in the Caribbean significantly poorer in species. As for branching, the 789 species...

  7. Catecholamines and in vitro growth of pathogenic bacteria: enhancement of growth varies greatly among bacterial species

    Science.gov (United States)

    Belay, Tesfaye; Aviles, Hernan; Vance, Monique; Fountain, Kimberly; Sonnenfeld, Gerald

    2003-01-01

    The purpose of this study was to examine the effects of catecholamines on in vitro growth of a range of bacterial species, including anaerobes. Bacteria tested included: Porphyromonas gingivalis, Bacteriodes fragilis, Shigella boydii, Shigella sonnie, Enterobacter Sp, and Salmonella choleraesuis. The results of the current study indicated that supplementation of bacterial cultures in minimal medium with norepinephrine or epinephrine did not result in increased growth of bacteria. Positive controls involving treatment of Escherichia coli with catecholamines did result in increased growth of that bacterial species. The results of the present study extend previous observations that showed differential capability of catecholamines to enhance bacterial growth in vitro.

  8. Growth and Physiological Responses of Phaseolus Species to Salinity Stress

    Directory of Open Access Journals (Sweden)

    J. S. Bayuelo-Jiménez

    2012-01-01

    Full Text Available This paper reports the changes on growth, photosynthesis, water relations, soluble carbohydrate, and ion accumulation, for two salt-tolerant and two salt-sensitive Phaseolus species grown under increasing salinity (0, 60 and 90 mM NaCl. After 20 days exposure to salt, biomass was reduced in all species to a similar extent (about 56%, with the effect of salinity on relative growth rate (RGR confined largely to the first week. RGR of salt-tolerant species was reduced by salinity due to leaf area ratio (LAR reduction rather than a decline in photosynthetic capacity, whereas unit leaf rate and LAR were the key factors in determining RGR on salt-sensitive species. Photosynthetic rate and stomatal conductance decreased gradually with salinity, showing significant reductions only in salt-sensitive species at the highest salt level. There was little difference between species in the effect of salinity on water relations, as indicated by their positive turgor. Osmotic adjustment occurred in all species and depended on higher K+, Na+, and Cl− accumulation. Despite some changes in soluble carbohydrate accumulation induced by salt stress, no consistent contributions in osmotic adjustment could be found in this study. Therefore, we suggest that tolerance to salt stress is largely unrelated to carbohydrate accumulation in Phaseolus species.

  9. Growth response to ozone of annual species from Mediterranean pastures.

    Science.gov (United States)

    Gimeno, B S; Bermejo, V; Sanz, J; de la Torre, D; Elvira, S

    2004-11-01

    Ozone (O3) phytotoxicity has been reported on a wide range of plant species. However, scarce information has been provided regarding the sensitivity of semi-natural grassland species, especially those from dehesa Mediterranean grasslands, in spite of their great biological diversity and the high O3 levels recorded in the region. A screening study was carried out in open-top chambers (OTCs) to assess the O3-sensitivity of representative therophytes of these ecosystems based on the response of selected growth-related parameters. Three O3 treatments and 3 OTCs per treatment were used. Legume species were very sensitive to O3, because 78% of the tested species showed detrimental effects on their total biomass relative growth rate (RGR) following their exposure to O3. The Trifolium genus was particularly sensitive showing O3-induced adverse effects on most of the assessed parameters. Gramineae plants were less sensitive than Leguminosae species because detrimental effects on total biomass RGR were only observed in 14% of the assessed species. No relationship was found between relative growth rates when growing in clean air and O3 susceptibility. The implications of these effects on the performance of dehesa acidic grasslands and on the definition of ozone critical levels for the protection of semi-natural vegetation are discussed. Copyright 2004 Elsevier Ltd.

  10. Growth and enzyme production by three Penicillium species on monosaccharides

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Krogh, Astrid Mørkeberg; Krogh, Kristian Bertel Rømer

    2004-01-01

    The growth and preference for utilisation of various sugar by the Penicillium species Penicillium pinophilum IBT 4186, Penicillium persicinum IBT 13226 and Penicillium brasilianum IBT 20888 was studied in batch cultivations using various monosaccharides as carbon source, either alone or in mixtures...

  11. Growth responses to ozone in plant species from wetlands

    NARCIS (Netherlands)

    Franzaring, J.H.; Tonneijck, A.E.G.; Kooijman, A.W.N.; Dueck, Th.A.

    2000-01-01

    Ten wet grassland species were fumigated with four concentrations of ozone (charcoal-filtered air, non-filtered air and non-filtered air plus 25 or 50 nl 1-1 ozone) in open-top chambers during one growing season to investigate the long-term effect of this air pollutant on various growth variables.

  12. Growth Response of Selected Mangrove Species to Domestic ...

    African Journals Online (AJOL)

    The sewage system of Dar es Salaam City, Tanzania, serves only 15% of the population, making sewage one of the leading sources of marine pollution. This study was initiated to assess the potential of peri-urban mangrove forests as filters and phyto-remediators of sewage and the growth of two mangrove species under ...

  13. Growth measurement of some amylolytic bacillus species in three media

    International Nuclear Information System (INIS)

    Ajayi, A.O.

    2009-01-01

    Study of the growth pattern of some Bacillus species on starchy substrates showed that the metabolic activity affected the enzymatic activity. B. subtilis (WBS), B. licheniformis (WBL) and B. coagulans (MBC) generally had higher growth rate. B. circulans (SBC) and B. coagulans (WBC) had higher growth on cornstarch medium with corresponding higher beta-amylase production as compared to other strains such as B. polymyxa. Ten of the 13 Bacillus species studied had better performance on cornstarch than on soluble starch except B. macerans (MBM), B. macerans (SMB2) and B. subtilis (WBS). The enzyme production ranged from 0.022 unit/cfu x 102 to 0.912 unit/cfu x 102 on cornstarch and 0.01 unit/cfu x 102 to 0.693 unit/cfu x 102 on soluble starch. Relatively higher a-amylase activity was observed in B. subtilis, B. licheniformis, B. macerans and B. circulans (WBC1). (author)

  14. Growth response to ozone of annual species from Mediterranean pastures

    Energy Technology Data Exchange (ETDEWEB)

    Gimeno, B.S. [Ecotoxicology of Air Pollution, CIEMAT (ed. 70), Avda, Complutense 22, 28040 Madrid (Spain)]. E-mail: benjamin.gimeno@ciemat.es; Bermejo, V. [Ecotoxicology of Air Pollution, CIEMAT (ed. 70), Avda, Complutense 22, 28040 Madrid (Spain)]. E-mail: Victoria.bermejo@ciemat.es; Sanz, J. [Ecotoxicology of Air Pollution, CIEMAT (ed. 70), Avda, Complutense 22, 28040 Madrid (Spain)]. E-mail: j.sanz@ciemat.es; Torre, D. de la [Ecotoxicology of Air Pollution, CIEMAT (ed. 70), Avda, Complutense 22, 28040 Madrid (Spain)]. E-mail: daniel.torre@ciemat.es; Elvira, S. [Ecotoxicology of Air Pollution, CIEMAT (ed. 70), Avda, Complutense 22, 28040 Madrid (Spain)]. E-mail: susana.elvira@ciemat.es

    2004-11-01

    Ozone (O{sub 3}) phytotoxicity has been reported on a wide range of plant species. However, scarce information has been provided regarding the sensitivity of semi-natural grassland species, especially those from dehesa Mediterranean grasslands, in spite of their great biological diversity and the high O{sub 3} levels recorded in the region. A screening study was carried out in open-top chambers (OTCs) to assess the O{sub 3}-sensitivity of representative therophytes of these ecosystems based on the response of selected growth-related parameters. Three O{sub 3} treatments and 3 OTCs per treatment were used. Legume species were very sensitive to O{sub 3}, because 78% of the tested species showed detrimental effects on their total biomass relative growth rate (RGR) following their exposure to O{sub 3}. The Trifolium genus was particularly sensitive showing O{sub 3}-induced adverse effects on most of the assessed parameters. Gramineae plants were less sensitive than Leguminosae species because detrimental effects on total biomass RGR were only observed in 14% of the assessed species. No relationship was found between relative growth rates when growing in clean air and O{sub 3} susceptibility. The implications of these effects on the performance of dehesa acidic grasslands and on the definition of ozone critical levels for the protection of semi-natural vegetation are discussed. - Capsule: The therophytes from dehesa acidic pastures of central of the Iberian peninsula present a great sensitivity to ozone, as derived from growth- and biomass-related variables.

  15. Growth of Populus and Salix Species under Compost Leachate Irrigation

    Directory of Open Access Journals (Sweden)

    Tooba Abedi

    2014-12-01

    Full Text Available According to the known broad variation in remediation capacity, three plant species were used in the experiment: two fast growing poplar’s clones - Populus deltoides, Populus euramericana, and willows Salix alba. Populus and Salix cuttings were collected from the nursery of the Populus Research Center of Safrabasteh in the eastern part of Guilan province at north of Iran. The Populus clones were chosen because of their high biomass production capacity and willow- because it is native in Iran. The highest diameter growth rate was exhibited for all three plant species by the 1:1 treatment with an average of 0.26, 0.22 and 0.16 cm in eight months period for P. euroamericana, P. deltoides and S. alba, respectively. Over a period of eight months a higher growth rate of height was observed in (P and (1:1 treatment for S. alba (33.70 and 15.77 cm, respectively and in (C treatment for P. deltoides (16.51 cm. P. deltoides and S. alba produced significantly (p<0.05 smaller aboveground biomass in (P treatment compared to all species. P. deltoides exhibited greater mean aboveground biomass in the (1:1 treatment compared to other species. There were significant differences (p<0.05 in the growth of roots between P. deltoides, P. euramericana and S. alba in all of the treatments.

  16. Species differences in seedling growth and leaf water response to ...

    African Journals Online (AJOL)

    The effect of different levels of R:FR was studied on seedlings of four Ghanaian timber species of different ecological guilds to assess their growth and leaf water response to changes in R:FR. The experiment was conducted in shade houses of varying light qualities (0.30, 0.46 and 0.76 R:FR) achieved with the use of ...

  17. Flooding, root temperature, physiology and growth of two Annona species.

    Science.gov (United States)

    Ojeda, Maritza; Schaffer, Bruce; Davies, Frederick S

    2004-09-01

    The effects of root zone temperature (RZT) and flooding on physiology and growth of Annona glabra L. (pond apple) and A. muricata L. (soursop) were investigated. Trees planted in containers were exposed to RZTs of 5, 10, 20, 25 or 35 degrees C in controlled root temperature chambers. Trees at each RZT were either non-flooded (control) or continuously flooded. There were four replications over time for each treatment combination. Pond apple was more flood-tolerant than soursop. A combination of flooding and RZTs of 5 and 10 degrees C resulted in tree mortality of both species by Week 4. Only trees that appeared to develop morphological adaptations survived continuous flooding. In both species, net CO2 assimilation (A) decreased to nearly zero within 1 week following exposure to RZTs of 5 or 10 degrees C and became consistently negative over the remaining experimental period. Flooding reduced leaf chlorophyll index (measured with a SPAD meter), A and plant growth, and increased root electrolyte leakage from soursop. Optimum growth occurred at RZTs of 25 to 35 degrees C for non-flooded pond apple trees and at 20 to 25 degrees C for flooded trees. Soursop exhibited maximum growth at RZTs of 35 degrees C under non-flooded conditions and at 25 degrees C under flooded conditions.

  18. Recent growth of conifer species of western North America: Assessing spatial patterns of radial growth trends

    Science.gov (United States)

    McKenzie, D.; Hessl, Amy E.; Peterson, D.L.

    2001-01-01

    We explored spatial patterns of low-frequency variability in radial tree growth among western North American conifer species and identified predictors of the variability in these patterns. Using 185 sites from the International Tree-Ring Data Bank, each of which contained 10a??60 raw ring-width series, we rebuilt two chronologies for each site, using two conservative methods designed to retain any low-frequency variability associated with recent environmental change. We used factor analysis to identify regional low-frequency patterns in site chronologies and estimated the slope of the growth trend since 1850 at each site from a combination of linear regression and time-series techniques. This slope was the response variable in a regression-tree model to predict the effects of environmental gradients and species-level differences on growth trends. Growth patterns at 27 sites from the American Southwest were consistent with quasi-periodic patterns of drought. Either 12 or 32 of the 185 sites demonstrated patterns of increasing growth between 1850 and 1980 A.D., depending on the standardization technique used. Pronounced growth increases were associated with high-elevation sites (above 3000 m) and high-latitude sites in maritime climates. Future research focused on these high-elevation and high-latitude sites should address the precise mechanisms responsible for increased 20th century growth.

  19. Characterizing Tropical Tree Species Growth Strategies: Learning from Inter-Individual Variability and Scale Invariance

    Science.gov (United States)

    Le Bec, Jimmy; Courbaud, Benoit; Le Moguédec, Gilles; Pélissier, Raphaël

    2015-01-01

    Understanding how tropical tree species differ in their growth strategies is critical to predict forest dynamics and assess species coexistence. Although tree growth is highly variable in tropical forests, species maximum growth is often considered as a major axis synthesizing species strategies, with fast-growing pioneer and slow-growing shade tolerant species as emblematic representatives. We used a hierarchical linear mixed model and 21-years long tree diameter increment series in a monsoon forest of the Western Ghats, India, to characterize species growth strategies and question whether maximum growth summarizes these strategies. We quantified both species responses to biotic and abiotic factors and individual tree effects unexplained by these factors. Growth responses to competition and tree size appeared highly variable among species which led to reversals in performance ranking along those two gradients. However, species-specific responses largely overlapped due to large unexplained variability resulting mostly from inter-individual growth differences consistent over time. On average one-third of the variability captured by our model was explained by covariates. This emphasizes the high dimensionality of the tree growth process, i.e. the fact that trees differ in many dimensions (genetics, life history) influencing their growth response to environmental gradients, some being unmeasured or unmeasurable. In addition, intraspecific variability increased as a power function of species maximum growth partly as a result of higher absolute responses of fast-growing species to competition and tree size. However, covariates explained on average the same proportion of intraspecific variability for slow- and fast-growing species, which showed the same range of relative responses to competition and tree size. These results reflect a scale invariance of the growth process, underlining that slow- and fast-growing species exhibit the same range of growth strategies. PMID

  20. Characterizing tropical tree species growth strategies: learning from inter-individual variability and scale invariance.

    Directory of Open Access Journals (Sweden)

    Jimmy Le Bec

    Full Text Available Understanding how tropical tree species differ in their growth strategies is critical to predict forest dynamics and assess species coexistence. Although tree growth is highly variable in tropical forests, species maximum growth is often considered as a major axis synthesizing species strategies, with fast-growing pioneer and slow-growing shade tolerant species as emblematic representatives. We used a hierarchical linear mixed model and 21-years long tree diameter increment series in a monsoon forest of the Western Ghats, India, to characterize species growth strategies and question whether maximum growth summarizes these strategies. We quantified both species responses to biotic and abiotic factors and individual tree effects unexplained by these factors. Growth responses to competition and tree size appeared highly variable among species which led to reversals in performance ranking along those two gradients. However, species-specific responses largely overlapped due to large unexplained variability resulting mostly from inter-individual growth differences consistent over time. On average one-third of the variability captured by our model was explained by covariates. This emphasizes the high dimensionality of the tree growth process, i.e. the fact that trees differ in many dimensions (genetics, life history influencing their growth response to environmental gradients, some being unmeasured or unmeasurable. In addition, intraspecific variability increased as a power function of species maximum growth partly as a result of higher absolute responses of fast-growing species to competition and tree size. However, covariates explained on average the same proportion of intraspecific variability for slow- and fast-growing species, which showed the same range of relative responses to competition and tree size. These results reflect a scale invariance of the growth process, underlining that slow- and fast-growing species exhibit the same range of growth

  1. Growth strategies of tropical tree species: disentangling light and size effects.

    Directory of Open Access Journals (Sweden)

    Nadja Rüger

    Full Text Available An understanding of the drivers of tree growth at the species level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in species-rich tropical forests, it is largely unknown how species differ in their response of growth to resource availability and individual size. We use a hierarchical bayesian approach to quantify the impact of light availability and tree diameter on growth of 274 woody species in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual tree was estimated from yearly vertical censuses of canopy density. The hierarchical bayesian approach allowed accounting for different sources of error, such as negative growth observations, and including rare species correctly weighted by their abundance. All species grew faster at higher light. Exponents of a power function relating growth to light were mostly between 0 and 1. This indicates that nearly all species exhibit a decelerating increase of growth with light. In contrast, estimated growth rates at standardized conditions (5 cm dbh, 5% light varied over a 9-fold range and reflect strong growth-strategy differentiation between the species. As a consequence, growth rankings of the species at low (2% and high light (20% were highly correlated. Rare species tended to grow faster and showed a greater sensitivity to light than abundant species. Overall, tree size was less important for growth than light and about half the species were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and tree diameter only explained on average 12% of the variation in growth rates. Thus, other factors such as soil characteristics, herbivory, or pathogens may contribute considerably to shaping tree growth in the tropics.

  2. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    Science.gov (United States)

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated. © 2014 John Wiley & Sons Ltd.

  3. Growth characteristics of two tropical forest species Warburgia ...

    African Journals Online (AJOL)

    Growth parameters for seedlings of two forest trees, Warburgia ugandensis and Polyscias fulva, were measured under various light growth conditions. Leaf area and plant height were significantly higher under low light (< 42% full sunlight) than high light (65% of sunlight) growth conditions (P<0.001). Plant leaf area ranged ...

  4. Growth characteristics of two tropical forest species Warburgia ...

    African Journals Online (AJOL)

    Administrator

    2008-01-11

    Jan 11, 2008 ... Growth parameters for seedlings of two forest trees, Warburgia ugandensis and Polyscias fulva, were measured under various light growth conditions. Leaf area and plant height were significantly higher under low light (< 42% full sunlight) than high light (65% of sunlight) growth conditions (P<0.001). Plant.

  5. Growth rings in tree species from the Tana river floodplain, Kenya ...

    African Journals Online (AJOL)

    Growth rings of 19 tree species obtained from the Tana riverine forests in Kenya were studied for potential usefulness in dendrochronology. Among the growth ring characteristics used to qualitatively evaluate the potential usefulness of each species for dendrochronology included: distinctiveness of ring boundaries, ring ...

  6. Growth Response and Tolerance to Heavy Metals of two Swamp Species inoculated with a Plant Growth-Promoting Rhizobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Dorantes, A.; Labra-Cardon, D.; Guerrero-Zuniga, A.; Montes-Villafan, S.

    2009-07-01

    Due to the sensitivity and the sequestration ability of the microbial communities to heavy metals, microbes have been used for bioremediation. Recently the application of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of this kind of contaminants has been done. This study evaluated the growth response and the tolerance to heavy metals of two swamp species. (Author)

  7. Growth Response and Tolerance to Heavy Metals of two Swamp Species inoculated with a Plant Growth-Promoting Rhizobacteria

    International Nuclear Information System (INIS)

    Rodriguez-Dorantes, A.; Labra-Cardon, D.; Guerrero-Zuniga, A.; Montes-Villafan, S.

    2009-01-01

    Due to the sensitivity and the sequestration ability of the microbial communities to heavy metals, microbes have been used for bioremediation. Recently the application of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of this kind of contaminants has been done. This study evaluated the growth response and the tolerance to heavy metals of two swamp species. (Author)

  8. Growth enhancement and gene expression of Arabidopsis thaliana irradiated with active oxygen species

    Science.gov (United States)

    Watanabe, Satoshi; Ono, Reoto; Hayashi, Nobuya; Shiratani, Masaharu; Tashiro, Kosuke; Kuhara, Satoru; Inoue, Asami; Yasuda, Kaori; Hagiwara, Hiroko

    2016-07-01

    The characteristics of plant growth enhancement effect and the mechanism of the enhancement induced by plasma irradiation are investigated using various active species in plasma. Active oxygen species in oxygen plasma are effective for growth enhancement of plants. DNA microarray analysis of Arabidopsis thaliana indicates that the genes coding proteins that counter oxidative stresses by eliminating active oxygen species are expressed at significantly high levels. The size of plant cells increases owing to oxygen plasma irradiation. The increases in gene expression levels and cell size suggest that the increase in the expression level of the expansin protein is essential for plant growth enhancement phenomena.

  9. Growth models for six Eucalyptus species in Angola | Delgado ...

    African Journals Online (AJOL)

    This study developed growth models for Eucalyptus saligna Sm., E. camaldulensis Dehnh., E. macarthurii H.Deane & Maiden, E. resinifera Sm., E. siderophloia Benth. and E. grandis Hill ex. Maiden, for the central highlands of Angola, and used these models to simulate the development of stand characteristics.

  10. Early Growth Of Some Introduced Agroforestry Species In Akure ...

    African Journals Online (AJOL)

    This study investigated the early growth performance of potted seedlings of Grevillea robusta, Dalbergia sissoo, Albizia lebbeck, Prosopis juliflora and Acacia mearnsii . Two types of potting containers were used - the conventional black polypot (size: 10 cm x 15 cm) and the transparent \\"pure water\\' bags (size: 14 cm x 15 ...

  11. Growth performance of lesser-known Leucaena species ...

    African Journals Online (AJOL)

    Based on these findings, provenances L. diversifolia Batch (15551), L. diversifolia Ex. Mexico, L. diversifolia Ex. Veracruz and L. pallida Ex. Oaxaca are recommended for Gairo and similar sites. Keywords: Lesser-known Leucaena, survival, growth, biomass production and psyllid resistance No Abstract. Southern African ...

  12. Assessment of Growth Performance of Two Cultivated Okra Species ...

    African Journals Online (AJOL)

    Prof. Ogunji

    obtained as top soil from the experimental garden of the Department of Plant Biology and. Biotechnology, University of Benin. ... The common Okra (A. esculentus) is mainly grown for market gardening in areas with limited rainfall, especially under irrigation. ..... Effect of crude oil pollution on the growth of Zea mays,.

  13. Modelling dimensional growth of three street tree species in the ...

    African Journals Online (AJOL)

    The results could also be used in the process of modelling energy use reduction, air pollution uptake, rainfall interception, carbon sequestration and microclimate modification of urban forests such as those found in the City of Tshwane. Keywords: allometry; regression; size relationships; tree growth; urban forests. Southern ...

  14. Interference of five problematic weed species with rice growth and ...

    African Journals Online (AJOL)

    Five weed species namely, Cyperus rotundus L., Cyperus difformis L., Echinochloa colonum (L.) Link., Paspalum paspaloides (Mich.) Scribner, and Marsilea minuta L. were selected for the assessment of their level of competition with two commonly grown rice varieties viz. Basmati-385 and Super Basmati. Root and shoot ...

  15. Growth Responses of Two Cultivated Okra Species (Abelmoschus ...

    African Journals Online (AJOL)

    Abelmoschus esculentus was investigated using six accessions; three for each species in crude oil contaminated soil. The seeds ..... industrial waste. Environmental and Experimental. Botany, 52.79-88. Siemonsma, J. S and Hamon, S. (2002). Abelmoschus caillei (A. chev) Stevels. In: Oyen, L.P.A. and. Lemmens R.H.M. ...

  16. Effect of Environmental Factors on the Growth of Aspergillus Species ...

    African Journals Online (AJOL)

    30 o. C and 35 o. C may be susceptible to contamination by Aspergillus species. ... Aspergillus are common contaminants of food and feed stuffs ... Emerging fungal colonies were continuously sub-cultured on potato dextrose agar plates to obtain pure cultures of the isolates. The fungi were identified based on cultural and ...

  17. Root plasticity maintains growth of temperate grassland species

    NARCIS (Netherlands)

    Padilla, F.M.; Aarts, B.H.J.; Roijendijk, Y.O.A.; Caluwe, de H.; Mommer, L.; Visser, E.J.W.; Kroon, de H.

    2013-01-01

    Background and aims The frequency of rain is predicted to change in high latitude areas with more precipitation in heavy, intense events interspersed by longer dry periods. These changes will modify soil drying cycles with unknown consequences for plant performance of temperate species. Methods We

  18. Growth response of eight tropical turfgrass species to salinity

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... MATERIALS AND METHODS. The experiment was conducted in the glasshouse of Faculty of. Agriculture at Universiti Putra Malaysia under sand culture system. Eight turfgrass (Table 1) species were planted in plastic pot filled with a mix of 9 washed river sand: 1 peat moss (v/v). The soil was sandy with pH ...

  19. Evidence for Divergent Evolution of Growth Temperature Preference in Sympatric Saccharomyces Species

    Science.gov (United States)

    Gonçalves, Paula; Valério, Elisabete; Correia, Cláudia; de Almeida, João M. G. C. F.; Sampaio, José Paulo

    2011-01-01

    The genus Saccharomyces currently includes eight species in addition to the model yeast Saccharomyces cerevisiae, most of which can be consistently isolated from tree bark and soil. We recently found sympatric pairs of Saccharomyces species, composed of one cryotolerant and one thermotolerant species in oak bark samples of various geographic origins. In order to contribute to explain the occurrence in sympatry of Saccharomyces species, we screened Saccharomyces genomic data for protein divergence that might be correlated to distinct growth temperature preferences of the species, using the dN/dS ratio as a measure of protein evolution rates and pair-wise species comparisons. In addition to proteins previously implicated in growth at suboptimal temperatures, we found that glycolytic enzymes were among the proteins exhibiting higher than expected divergence when one cryotolerant and one thermotolerant species are compared. By measuring glycolytic fluxes and glycolytic enzymatic activities in different species and at different temperatures, we subsequently show that the unusual divergence of glycolytic genes may be related to divergent evolution of the glycolytic pathway aligning its performance to the growth temperature profiles of the different species. In general, our results support the view that growth temperature preference is a trait that may have undergone divergent selection in the course of ecological speciation in Saccharomyces. PMID:21674061

  20. Allometry and growth of six tree species in a terra firme forest in colombian amazonia

    International Nuclear Information System (INIS)

    Giraldo Pamplona Wilson A; Dairon, Alvaro; Cardenas Montoya J, Duque

    2011-01-01

    In this study carried out in the Amacayacu National Park in the Colombian Amazonia, we assessed the allometric relationship among different tree structural variables and the growth in diameter and biomass of six species classified according to their wood specific gravity. The tree species chosen were Eschweilera rufolia, Eschweilera itayensis, Conceveiba guianensis, Otoba parvifolia, Pseudolmedia laevis, and Apeiba aspera. The dbh was the most important structural explanatory variable. Regarding the total height dbh model, the allometric coefficient b changed between species showing a trend to increase, and thus a taper decrease, proportional to. There were o significant differences in diameter growth between species (P=0.119, F=1.80) or functional groups (P=0.153, F= 1.19). Likewise, biomass growth did not show significant differences neither between species (P=0.0784, F=2.05) nor functional groups (P=0.0711, F=2.71). However, there was a positive trend between and diameter growth and a negative one between and biomass growth. The results of this study suggest that this forest is recovering in biomass at a constant rate independent of the patch age, which emphasizes on the importance of pioneer species and gap formation on the carbon dynamics and the species coexistence in Amazonian tierra firme forests.

  1. Nature and periodicity of growth rings in two Bangladeshi mangrove species

    NARCIS (Netherlands)

    Chowdhury, Q.; Schmitz, N.; Verheyden, A.; Sass-Klaassen, U.; Koedam, N.; Beeckman, H.

    2008-01-01

    Nature and periodicity of growth rings were investigated in Sonneratia opetala and Heritiera fomes, two Bangladeshi mangrove species. From both species we collected three stem discs in the natural forest reserve of the Sundarbans. In addition, three discs were sampled from plantation-grown S.

  2. Basal area growth for 15 tropical trees species in Puerto Rico. Forest

    Science.gov (United States)

    B. R. Parresol

    1995-01-01

    The tabonuco forest of Puerto Rico support a diverse population of tree species valued for timber, fuel, food, wildlife food and cover, and erosion control among other use. tree basal area growth data spanning 39 years are avaible on 15 species from eigth permanent plots in Luquillo Experimental Forest. The complexity of the rain forest challeges current forest...

  3. Leaf traits determine the growth-survival trade-off across rain forest tree species

    NARCIS (Netherlands)

    Sterck, F.J.; Poorter, L.; Schieving, F.

    2006-01-01

    A dominant hypothesis explaining tree species coexistence in tropical forest is that trade-offs in characters allow species to adapt to different light environments, but tests for this hypothesis are scarce. This study is the first that uses a theoretical plant growth model to link leaf trade-offs

  4. Linking root traits to potential growth rate in six temperate tree species

    NARCIS (Netherlands)

    Comas, L.H.; Bouma, T.J.; Eissenstat, D.M.

    2002-01-01

    There is an extremely limited understanding of how plants of different potential growth rate vary in root traits, especially in woody species. We contrasted fine root morphology, physiology, and elemental construction between a fast- and a slow-growing species in each of three families: Aceraceae

  5. A structurally based analytic model of growth and biomass dynamics in single species stands of conifers

    Science.gov (United States)

    Robin J. Tausch

    2015-01-01

    A theoretically based analytic model of plant growth in single species conifer communities based on the species fully occupying a site and fully using the site resources is introduced. Model derivations result in a single equation simultaneously describes changes over both, different site conditions (or resources available), and over time for each variable for each...

  6. Plant species differ in early seedling growth and tissue nutrient responses to arbuscular and ectomycorrhizal fungi.

    Science.gov (United States)

    Holste, Ellen K; Kobe, Richard K; Gehring, Catherine A

    2017-04-01

    Experiments with plant species that can host both arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) are important to separating the roles of fungal type and plant species and understanding the influence of the types of symbioses on plant growth and nutrient acquisition. We examined the effects of mycorrhizal fungal type on the growth and tissue nutrient content of two tree species (Eucalyptus grandis and Quercus costaricensis) grown under four nutrient treatments (combinations of low versus high nitrogen (N) and phosphorus (P) with different N:P ratios) in the greenhouse. Trees were inoculated with unidentified field mixtures of AMF or EMF species cultivated on root fragments of AMF- or EMF-specific bait plants. In E. grandis, inoculation with both AMF and EMF positively affected belowground plant dry weight and negatively affected aboveground dry weight, while only inoculation with AMF increased tissue nutrient content. Conversely, Q. costaricensis dry weight and nutrient content did not differ significantly among inoculation treatments, potentially due to its dependence on cotyledon reserves for growth. Mineral nutrition of both tree species differed with the ratio of N to P applied while growth did not. Our results demonstrate that both tree species' characteristics and the soil nutrient environment can affect how AMF and EMF interact with their host plants. This research highlights the importance of mycorrhizal fungal-tree-soil interactions during early seedling growth and suggests that differences between AMF and EMF associations may be crucial to understanding forest ecosystem functioning.

  7. Growth and reproduction respond differently to climate in three Neotropical tree species.

    Science.gov (United States)

    Alfaro-Sánchez, Raquel; Muller-Landau, Helene C; Wright, S Joseph; Camarero, J Julio

    2017-06-01

    The response of tropical forests to anthropogenic climate change is critically important to future global carbon budgets, yet remains highly uncertain. Here, we investigate how precipitation, temperature, solar radiation and dry- and wet-season lengths are related to annual tree growth, flower production, and fruit production in three moist tropical forest tree species using long-term datasets from tree rings and litter traps in central Panama. We also evaluated how growth, flower, and fruit production were interrelated. We found that growth was positively correlated with wet-season precipitation in all three species: Jacaranda copaia (r = 0.63), Tetragastris panamensis (r = 0.39) and Trichilia tuberculata (r = 0.39). Flowering and fruiting in Jacaranda were negatively related to current-year dry-season rainfall and positively related to prior-year dry-season rainfall. Flowering in Tetragastris was negatively related to current-year annual mean temperature while Trichilia showed no significant relationships of reproduction with climate. Growth was significantly related to reproduction only in Tetragastris, where it was positively related to previous year fruiting. Our results suggest that tree growth in moist tropical forest tree species is generally reduced by drought events such as those associated with strong El Niño events. In contrast, interannual variation in reproduction is not generally associated with growth and has distinct and species-specific climate responses, with positive effects of El Niño events in some species. Understanding these contrasting climate effects on tree growth and reproduction is critical to predicting changes in tropical forest dynamics and species composition under climate change.

  8. The Effect of Various Species of Macroalgae on the Growth, Survival, and Toxicity of Karenia brevis

    Science.gov (United States)

    Gardner, K. G.; Lovko, V. J.; Henry, M. S.

    2016-02-01

    Harmful algal blooms (HABs) caused by the dinoflagellate Karenia brevis produce toxins that result in negative impacts to both humans and the environment. Little is known about the termination stages of these blooms, and few viable control mechanisms have been suggested. Natural, algae derived compounds have been proposed as a way to limit bloom growth and reduce brevetoxins in the water column. The work presented here examines the ability of macroalgae to inhibit the growth or survival of K. brevis, similar to what has been demonstrated with other red tide species. Additionally, we attempted to determine if macroalgae decreases water column brevetoxins which, to our knowledge, has not been tested with macroalgae but has been demonstrated in other studies with microalgal species. The macroalgae species Dictyota sp. and Gracilaria sp. caused 100% mortality of K. brevis in under 24 hours. Compared to the control, 7 other species significantly decreased the growth rate of K. brevis. The Dictyota treatments showed significant toxin reduction and increase of the antitoxin brevanol. These results indicate that some combination of compounds produced by macroalgae inhibit growth and survival of K. brevis and possibly limit their toxin production. Future studies will attempt to isolate and identify these compounds and test their effects on other marine organisms such as diatoms. Determining the interactions between HAB species K. brevis and macroalgal species will provide insights on the mechanism of bloom termination and a potential control method.

  9. Contrasting shrub species respond to early summer temperatures leading to correspondence of shrub growth patterns

    Science.gov (United States)

    Weijers, Stef; Pape, Roland; Löffler, Jörg; Myers-Smith, Isla H.

    2018-03-01

    The Arctic-alpine biome is warming rapidly, resulting in a gradual replacement of low statured species by taller woody species in many tundra ecosystems. In northwest North America, the remotely sensed normalized difference vegetation index (NDVI), suggests an increase in productivity of the Arctic and alpine tundra and a decrease in productivity of boreal forests. However, the responses of contrasting shrub species growing at the same sites to climate drivers remain largely unexplored. Here, we test growth, climate, and NDVI relationships of two contrasting species: the expanding tall deciduous shrub Salix pulchra and the circumarctic evergreen dwarf shrub Cassiope tetragona from an alpine tundra site in the Pika valley in the Kluane Region, southwest Yukon Territories, Canada. We found that annual growth variability of both species at this site is strongly driven by early summer temperatures, despite their contrasting traits and habitats. Shrub growth chronologies for both species were correlated with the regional climate signal and showed spatial correspondence with interannual variation in NDVI in surrounding alpine and Arctic regions. Our results suggest that early summer warming represents a common driver of vegetation change for contrasting shrub species growing in different habitats in the same alpine environments.

  10. Climate Responses in Growth and Wood Anatomy of Imoprtant Forest Tree Species in Denmark

    DEFF Research Database (Denmark)

    Huang, Weiwei

    and decrease forest productivity. Q. robur is expected not only to tolerate the expected future climate including increasing water stress but also will presumably even prosper from the rising temperature. All other tested species are expected to have decreased growth and vitality, but to different degrees......The expected changes in global and regional climate, like drought episodes and increasing temperatures, are a challenge for forest management, as they will affect growth, mortalit y and species composition of future forests directly and mostly negatively. However, the long-term impacts of drought....... Based on the present results and supported by literature it is concluded that projected more severe and frequent drought episodes and higher autumn and summer temperatures will substantially affect the growth and xylem anatomy of most important temperate forest species and may change forest composition...

  11. Uranium mobility across annual growth rings in three deciduous tree species.

    Science.gov (United States)

    McHugh, Kelly C; Widom, Elisabeth; Spitz, Henry B; Wiles, Gregory C; Glover, Sam E

    2018-02-01

    Black walnut (Juglans nigra), slippery elm (Ulmus rubra), and white ash (Fraxinus americana) trees were evaluated as potential archives of past uranium (U) contamination. Like other metals, U mobility in annual growth rings of trees is dependent on the tree species. Uranium concentrations and isotopic compositions (masses 234, 235, 236, and 238) were analyzed by thermal ionization mass spectrometry to test the efficacy of using tree rings to retroactively monitor U pollution from the FFMPC, a U purification facility operating from 1951 to 1989. This study found non-natural U (depleted U and detectable 236 U) in growth rings of all three tree species that pre-dated the start of operations at FFMPC and compositional trends that did not correspond with known contamination events. Therefore, the annual growth rings of these tree species cannot be used to reliably monitor the chronology of U contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Growth of a Species, an Association, a Science: 80 Years of Growth and Development Research

    Science.gov (United States)

    Sherwood, Richard J.; Duren, Dana L.

    2014-01-01

    Physical anthropological research was codified in the United States with the creation of the American Association of Physical Anthropology (AAPA) in 1929. That same year, a study began in yellow springs, Ohio, with a goal of identifying “what makes people different.” The approach used to answer that question was to study the growth and development of Homo sapiens. The resulting study, the Fels Longitudinal Study, is currently the longest continuous study of human growth and development in the world. Although the AAPA and the Fels Longitudinal Study have existed as separate entities for more than 80 years now, it is not surprising, given the relationship between anatomical and developmental research, there has been considerable overlap between the two. As the field of physical anthropology has blossomed to include subdisciplines such as forensics, genetics, primatology, as well as sophisticated statistical methodologies, the importance of growth and development research has escalated. Although current Fels Longitudinal Study research is largely directed at biomedical questions, virtually all findings are relevant to physical anthropology, providing insights into basic biological processes and life history parameters. Some key milestones from the early years of the AAPA and the Fels Longitudinal Study are highlighted here that address growth and development research in physical anthropology. These are still held as fundamental concepts that underscore the importance of this line of inquiry, not only across the subdisciplines of physical anthropology, but also among anthropological, biological, and biomedical inquiries. PMID:23283658

  13. Effect of water activity and temperature on the growth of Eurotium species isolated from animal feeds.

    Science.gov (United States)

    Greco, Mariana; Pardo, Alejandro; Pose, Graciela; Patriarca, Andrea

    Xerophilic fungi represent a serious problem due to their ability to grow at low water activities causing the spoiling of low and intermediate moisture foods, stored goods and animal feeds, with the consequent economic losses. The combined effect of water activity and temperature of four Eurotium species isolated from animal feeds was investigated. Eurotium amstelodami, Eurotium chevalieri, Eurotium repens and Eurotium rubrum were grown at 5, 15, 25, 37 and 45°C on malt extract agar adjusted with glycerol in the range 0.710-0.993 of water activities. The cardinal model proposed by Rosso and Robinson (2001) was applied to fit growth data, with the variable water activity at fixed temperatures, obtaining three cardinal water activities (a wmin , a wmax , a wopt ) and the specific growth rate at the optimum a w (μ opt ). A probabilistic model was also applied to define the interface between growth and no-growth. The cardinal model provided an adequate estimation of the optimal a w to grow and the maximum growth rate. The probabilistic model showed a good performance to fit growth/no-growth cases in the predicted range. The results presented here could be applied to predict Eurotium species growth in animal feeds. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Effects of saline tolerant Azospirillum species on the growth parameters of mangrove seedlings.

    Science.gov (United States)

    Ravikumar, S; Ignatiammal, S Thadedus Maria; Gnanadesigan, M; Kalaiarasi, A

    2012-09-01

    Five species of Azospirillum isolated from Manakkudi mangrove ecosystem were subjected for their efficiency to find out their growth parameters potential for the successful establishment of mangrove seedlings. Of the isolated five Azospirillum species, Azospirillum lipoferum (60%) was found to be the dominant one. But the level of maximum indole acetic acid (IAA) production (19.8 mg.ml(-1)) and nitrogen fixation (5.9 C2H2hr1) was identified with A. brasilense. Further, A. brasilense showed significant (p Azospirillum brasilense was found better for the growth of Avicennia officinalis and Ceriops decandra seedlings, but Azospirillum irakense was found better for Rhizophora apiculata seedlings.

  15. Growth response and ionic relation in two brassica species under water stress conditions

    International Nuclear Information System (INIS)

    Zaman, B.U.; Salim, M.; Niazi, B.H.; Ali, A.

    2008-01-01

    A glasshouse study of Brassica campestris and Brassica juncea showed that the growth and the ionic parameters of both the species were significantly (p < 0.0 I) affected due to water stress. Shoot length of both the species decreased consistently with decrease in solute potential (PSI) in the root medium. Relative growth rate and dry mass was higher in B. juncea than B. campestris but leaf area was less. Concentrations of K Ca/sup 2/ P and S generally decreased with gradual increase in water stress B. campestris was more susceptible to water stress than B juncea. (author)

  16. Tree Height and DBH Growth Model Establishment of Main Tree Species in Wuling Mountain Small Watershed

    Science.gov (United States)

    Luo, Jia; Zhang, Min; Zhou, Xiaoling; Chen, Jianhua; Tian, Yuxin

    2018-01-01

    Taken 4 main tree species in the Wuling mountain small watershed as research objects, 57 typical sample plots were set up according to the stand type, site conditions and community structure. 311 goal diameter-class sample trees were selected according to diameter-class groups of different tree-height grades, and the optimal fitting models of tree height and DBH growth of main tree species were obtained by stem analysis using Richard, Logistic, Korf, Mitscherlich, Schumacher, Weibull theoretical growth equations, and the correlation coefficient of all optimal fitting models reached above 0.9. Through the evaluation and test, the optimal fitting models possessed rather good fitting precision and forecast dependability.

  17. A phenomenological model of the growth of two-species atomic Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Pattinson, R W; Parker, N G; Proukakis, N P

    2014-01-01

    We introduce a phenomenological mean-field model to describe the growth of immiscible two-species atomic Bose-Einstein condensates towards some equilibrium. Our model is based on the coupled Gross-Pitaevskii equations with the addition of dissipative terms to account for growth. While our model may be applied generally, we take a recent Rb-Cs experiment [McCarron et al., Phys. Rev. A 84 011603(R) (2011)] as a case study. As the condensates grow, they can pass through ranging transient density structures which can be distinct from the equilibrium states, although such a model always predicts the predominance of one condensate species over longer evolution times.

  18. Spatial relationship of biomass and species distribution in an old-growth Pseudotsuga Tsuga forest.

    Science.gov (United States)

    Jiquan Chen; Bo Song; Mark Rudnicki; Melinda Moeur; Ken Bible; Malcolm North; Dave C. Shaw; Jerry F. Franklin; Dave M. Braun

    2003-01-01

    Old-growth forests are known for their complex and variable structure and function. In a 12-ha plot (300 m x 400 m) of an old-growth Douglas-fir forest within the T.T. Munger Research Natural Area in southern Washington, we mapped and recorded live/dead condition, species, and diameter at breast height to address the following objectives: (1) to quantify the...

  19. Influence of osmotic pressure on the growth of three species of the genus Zoophthora

    Directory of Open Access Journals (Sweden)

    Jerzy Piątkowski

    2013-12-01

    Full Text Available Strains accomodated in the genus Zoophthora are very sensitive to osmotic value of their habitat. Hipertonical molarity of buffers and NaCl decreases the growth, but this effect strongly depends on the species tested and on the kind of buffer. In 0.66% phtalan buffer the growth of Z. lanceolata is completely stopped whereas Z. psyllae and Z. aphrophora is inhibited only in 50% comparing to the control.

  20. Initial growth of six forest tree species in differents spacing conditions

    Directory of Open Access Journals (Sweden)

    Daniel Ferreira do Nascimento

    2012-03-01

    Full Text Available This work veriflied the influence of planting spacing on the initial growth of six forest species, at the age of 22 months, in plantations of forest recomposition in the Guandu River Basin. The experiment was installed in the SFE - thermoelectric power plants Barbosa Lima Sobrinho, located in the City of Seropédica-RJ. Forty eight tree species were planted, using the spacings, 1.0 x 1.0, 1.5 x 1.5, 2.0 and 2.0 x 3.0 x 2.0 m, which are the study treatments. At 22 months after planting, it was evaluated the growth in height, diameter at ground level (DNS and area of the canopy for the species, Anadenanthera macrocarpa Benth. Brenan (angico vermelho, Schinus terebinthifolius Raddi (aroeira pimenteira, Schizolobium parahyba Blake (guapuruvu Chorisia speciosa St. Hill (paineira, Cordia sp. (babosa branca and Inga marginata (ingá. It was found that the studied species behaved in a different way in the differents spacing of planting, and that the planting density significantly influenced on the initial growth of all the species. In general, in wider planting spacings, the plants had higher growth.

  1. Seedling growth and survival of selected wild edible fruit species of the Sikkim Himalaya, India

    Science.gov (United States)

    Sundriyal, Manju; Sundriyal, R. C.

    2005-07-01

    In the Sikkim Himalaya, an enormous variety of wild growing plants are exploited at large scale for collection of their edible parts, of which six most prominently utilized fruit species (viz., Baccaurea sapida, Diploknema butyracea, Elaeagnus latifolia, Eriolobus indica, Machilus edulis and Spondias axillaris) were investigated. The growth of nursery raised seedlings was measured at 3 month intervals until two years old in terms of absolute growth rate (AGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), leaf weight ratio (LWR), stem weight ratio (SWR), root weight ratio (RWR) and root-shoot ratio (RSR). Spondias axillaris and Machilus edulis had the maximum AGR, RGR, LAR and SWR among all species. LWR was highest for B. sapida. RGR, LAR and LWR declined with the age of seedlings. RGR was negatively correlated with NAR, SWR, RWR and RSR, though it showed a positive relationship with LAR. For all species, seedlings attained significant sizes after one year of age, and showed reasonable survival after transplantation into the farmers' fields. It is expected that information on the growth behaviour of these species would be useful while they are adopted into agroforestry systems. It is suggested that these species should be multiplied at large scale and distributed to the local inhabitants to reduce pressure on them in natural stands as well as provide economic benefit to the subsistence farmers.

  2. Effects of Drought and Rewetting on Growth and Gas Exchange of Minor European Broadleaved Tree Species

    Directory of Open Access Journals (Sweden)

    Jörg Kunz

    2016-10-01

    Full Text Available Widespread and economically important European tree species such as Norway spruce, Scots pine, and European beech are projected to be negatively affected by the increasing intensity and frequency of dry and hot conditions in a future climate. Hence, there is an increasing need to investigate the suitability of presumably more drought tolerant species to ensure future ecological stability, biodiversity, and productivity of forests. Based on their distribution patterns and climatic envelopes, the rare, minor broadleaved tree species Sorbus torminalis ((L. CRANTZ, S. domestica (L., Acer campestre (L., and A. platanoides (L. are assumed to be drought tolerant, however, there is only limited experimental basis to support that notion. This study aimed at quantifying growth and gas exchange of seedlings of these species during drought conditions, and their capacity to recover following drought. For that purpose, they were compared to the common companion species Quercus petraea ((MATTUSCHKA LIEBL. and Fagus sylvatica (L.. Here, potted seedlings of these species were exposed to water limitation followed by rewetting cycles in a greenhouse experiment. Photosynthesis and transpiration rates, stomatal conductance as well as root and shoot growth rates indicated a high drought resistance of A. campestre and A. platanoides. Sorbus domestica showed a marked ability to recover after drought stress. Therefore, we conclude that these minor tree species have the potential to enrich forests on drought-prone sites. Results from this pot experiment need to be complemented by field studies, in which the drought response of the species is not influenced by restrictions to root development.

  3. Seedling growth in greenhouse conditions of the forest species Dialium guianense (Aubl.) Sandwith

    OpenAIRE

    Georgina Vargas Simon; Reinaldo Pire; Martha Olivia Lazaro Dzul

    2018-01-01

    Dialium guianense is used for its wood and fruit production, and is a tropical tree species native to evergreen forests. Given the threat these forests face, the purpose of this work was to evaluate the initial growth of the plant under greenhouse conditions, for aiming in the development of propagation programs. Seedlings of the species were transplanted to nursery bags under a completely randomized design and grown for 10 months with an initial population of 200 plants. At the end of the ex...

  4. Seed germination and seedling growth of two Pseudobombax species (Malvaceae) with contrasting habitats from Brazilian Cerrado.

    Science.gov (United States)

    Mendes-Rodrigues, Clesnan; Oliveira, Paulo Eugênio; Ranal, Marli Aparecida

    2011-12-01

    Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas.

  5. Seed germination and seedling growth of two Pseudobombax species (Malvaceae with contrasting habitats from Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Clesnan Mendes-Rodrigues

    2011-12-01

    Full Text Available Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100% and mean germination time (ca. 12 days. However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots, dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas. Rev. Biol. Trop. 59 (4: 1915-1925. Epub 2011 December 01.

  6. GROWTH OF AMAZON NATIVE SPECIES SUBMITTED TO THE PLANTATION IN THE RORAIMA STATE

    Directory of Open Access Journals (Sweden)

    Helio Tonini

    2009-10-01

    Full Text Available An important forest research challenge in the Amazonian is finding forms of reforesting degraded areas with the use of a larger number of native species and identify tropical species commercially attractive adapted to clear-cut areas. This work had as objectives to evaluate the initial growth in diameter and height of six native Amazonian species in a preliminary species trial. The data were obtained from measures of 72 trees 9 years after planting. The selected species for this study were cupiúba (Goupia glabra, cumaru (Dipterix odorata, andiroba (Carapa guianensis, brazil nut (Bertholletia excelsa, pará-pará (Jacaranda copaia and tatajuba (Bagassa guianensis. The cumulative growth curves for diameter and height was obtained by the Chapman – Richards function. In spite of the low age of the stands, it was obtained good fit to the function for the studied species. Pará-pará (Jacaranda copaia, presented best diameter and height growth in all the ages. The diameter mean annual increment analysis showed that, except for the cupiúba (Goupia glabra,  can be expected  increments larger than  2 cm, by appropiate spacings and thinning.

  7. Provenance-specific growth responses to drought and air warming in three European oak species

    Energy Technology Data Exchange (ETDEWEB)

    Arend, Matthias; Kuster, Thomas; Gunthardt-Goerg, Madeleine S.; Dobbertin, Matthias

    2011-03-15

    This study evaluated oak growth responses to air warming through research conducted with species coming from climatically different sites submitted to differing climates including periodic drought and air warming. Results showed different responses to drought and air warming as an adaptation to the conditions, and differences in growth response from one provenance to another were found but local climate factors were not responsible. This study highlighted that provenance was important to growth responses and it will have to be taken into account for regeneration of oaks in a changed climate if these results are confirmed.

  8. Effects of Zn Deficiency and Bicarbonate on the Growth and Photosynthetic Characteristics of Four Plant Species

    Science.gov (United States)

    Zhao, Kuan; Wu, Yanyou

    2017-01-01

    Calcareous soils are characterized by low nutrient contents, high bicarbonate (HCO3−) content, and high alkalinity. The effects of HCO3− addition under zinc-sufficient (+Zn) and zinc-deficient (−Zn) conditions on the growth and photosynthetic characteristics of seedlings of two Moraceae species (Broussonetia papyrifera and Morus alba) and two Brassicaceae species (Orychophragmus violaceus and Brassica napus) were investigated. These four species were hydroponically grown in nutrient solution with 0 mM Zn (−Zn) or 0.02 mM Zn (+Zn) and 0 mM or 10 mM HCO3−. The photosynthetic response to HCO3− treatment, Zn deficiency, or both varied according to plant species. Of the four species, Broussonetia papyrifera showed the best adaptability to Zn deficiency for both the 0 mM and 10 mM HCO3− treatments due to its strong growth and minimal inhibition of photosynthesis and photosystem II (PS II). Brassica napus was sensitive to Zn deficiency, HCO3− treatment, or both as evidenced by the considerable inhibition of photosynthesis and high PS II activity. The results indicated different responses of various plant species to Zn deficiency and excess HCO3−. Broussonetia papyrifera was shown to have potential as a pioneer species in karst regions. PMID:28076430

  9. The influence of recent climate change on tree height growth differs with species and spatial environment.

    Science.gov (United States)

    Messaoud, Yassine; Chen, Han Y H

    2011-02-16

    Tree growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of tree growth to increased temperature and atmospheric carbon dioxide (CO₂) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant trees at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the tree growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both species was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO₂ concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO₂ concentration, did not only differ with tree species, but

  10. Life-history trait of the Mediterranean keystone species Patella rustica: growth and microbial bioerosion

    Directory of Open Access Journals (Sweden)

    I. PRUSINA

    2015-05-01

    Full Text Available The age and shell growth patterns in populations of Patella rustica of the Adriatic Sea were determined by analyzing the inner growth lines visible in shell sections. Marginal increment analysis showed annual periodicity with annual growth line being deposited in May. The growth analysis of 120 individual shells showed that 90.8 % of collected individuals were less than 4 years of age and only two individuals (1.6 % were older than 6 years. Population structure was described and the generalized von Bertalanffy growth parameters were calculated: asymptotic length (L∞ was 38.22 mm and the growth constant (K was 0.30 year-1. Growth performance index value of P. rustica (Ø’ was 2.64 and is among the lowest ranges reported for limpet species. Patella rustica shells were degraded to different degrees by microbial bioerosion. Microboring organisms identified were pseudofilamentous and filamentous cyanobacteria Hormathonema paulocellulare, Hyella caespitosa, Mastigocoleus testarum and Leptolyngbya sp. The overall intensity of infestation was relatively low, but increased in severity with shell length. The damage was most often restricted to the oldest parts of the shell, i.e. apex of the shell, posing difficulties in determining the exact position of the first growth line. The present study is first to introduce the use of inner growth lines in Patella rustica shell sections as a reliable method for age determination and it provides the first insight into the growth patterns of this keystone species while taking the interference of microbial shell bioerosion in consideration.

  11. Changes in the relationship between annual tree growth and climatic variables for four hardwood species

    Science.gov (United States)

    E.R. Smith; J.C. Rennie

    1991-01-01

    A study was conducted to characterize temporal and spatial variability in the growth response of four major hardwood species (white oak, chestnut oak, northern red oak, and yellow-poplar) to climatic fluctuations, and to evaluate the role of environmental factors associated with difference in response among individuals. The study incorporated tree-ring data collected...

  12. Different biomechanical design and ecophysiological strategies in juveniles of two liana species with contrasting growth habit

    NARCIS (Netherlands)

    Chen, Y.J.; Bongers, F.; Zhang, J.L.; Liu, J.Y.; Cao, K.F.

    2014-01-01

    Premise of the study: Lianas constitute a major functional type in tropical zones. While some liana species start climbing immediately after germination (shade-avoidance), others have a long self-supporting phase (shade-tolerance). The morphophysiological characteristics of these two growth habits

  13. Species-specific effects of a 1994 ice storm on radial tree growth in Delaware

    Science.gov (United States)

    Matthew Smolnik; Amy Hessl; J. J. Colbert

    2006-01-01

    Ice storms are recurrent disturbances that alter forest succession and forest structure throughout North America. However, long-term effects of ice storms on tree growth are largely unknown. Following a 1994 ice storm in Delaware, the Delaware Forest Service established seventy-five study plots to sample four species of trees (southern red oak [Quercus falcate...

  14. Effects of two different AMF species on growth and nutrient content ...

    African Journals Online (AJOL)

    This study was carried out to determine the effects of different Arbuscular Mycorrhizal Fungi (AMF) species on the growth and nutrient contents of pepper seedlings (cv. Demre) grown under moderate salt stress. Two different mychorrhizas (Glomus intraradices and Gigaspora margarita) were tested on a growing media ...

  15. 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...

  16. Growth and grazing responses of two chloroplast-retaining dinoflagellates: effect of irradiance and prey species

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik; Hansen, P.J.; Larsen, J.

    2000-01-01

    The effect of irradiance on growth and grazing responses of 2 phagotrophic dinoflagellates, Gymnodinium gracilentum Campbell 1973 and Amphidinium poecilochroum Larsen 1985, was studied. While G. gracilentum belongs to the plankton, A. poecilochroum is a benthic species that primarily feeds on prey...

  17. Complementary models of tree species-soil relationships in old-growth temperate forests

    Science.gov (United States)

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

  18. Bacterial growth rates are influenced by cellular characteristics of individual species when immersed in electromagnetic fields.

    Science.gov (United States)

    Tessaro, Lucas W E; Murugan, Nirosha J; Persinger, Michael A

    2015-03-01

    Previous studies have shown that exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) have negative effects on the rate of growth of bacteria. In the present study, two Gram-positive and two Gram-negative species were exposed to six magnetic field conditions in broth cultures. Three variations of the 'Thomas' pulsed frequency-modulated pattern; a strong-static "puck" magnet upwards of 5000G in intensity; a pair of these magnets rotating opposite one another at ∼30rpm; and finally a strong dynamic magnetic field generator termed the 'Resonator' with an average intensity of 250μT were used. Growth rate was discerned by optical density (OD) measurements every hour at 600nm. ELF-EMF conditions significantly affected the rates of growth of the bacterial cultures, while the two static magnetic field conditions were not statistically significant. Most interestingly, the 'Resonator' dynamic magnetic field increased the rates of growth of three species (Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli), while slowing the growth of one (Serratia marcescens). We suggest that these effects are due to individual biophysical characteristics of the bacterial species. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Effect of glyphosate on growth of four freshwater species of phytoplankton: a microplate bioassay.

    Science.gov (United States)

    Vendrell, E; Ferraz, D Gómez de Barreda; Sabater, C; Carrasco, J M

    2009-05-01

    The acute toxicity of glyphosate herbicide was tested on the four species of freshwater phytoplankton, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila. Herbicide concentrations eliciting a 50% growth reduction over 72 h (EC(50)) ranged from 24.5 to 41.7 mg L(-1), whilst a 10% growth inhibition is achieved by herbicide concentrations ranging from 1.6 to 3.0 mg L(-1), difficult to find neither in paddy fields (it is not used in rice) nor in the lake of the Albufera Natural Park. Chorella species are less sensitive to the herbicide than Scenedesmus species. It can be concluded that glyphosate has a low potential risk for the tested organisms.

  20. Survival and growth of three endangered oak species in a Mexican montane cloud forest

    Directory of Open Access Journals (Sweden)

    Ofelia Andrea Valdés-Rodríguez

    2017-07-01

    Full Text Available Cloud forests are amongst the world’s most impacted and endangered forest types, with Mexican cloud forests amongst the most degraded. These species rich forests are characterized by a diversity of congeneric oak species which dominate the canopy of mature forests. An improved understanding of the establishment requirements of oak seedlings in cloud forests is needed for conservation and restoration purposes. The aim of this study was to assess the influence of light conditions during early establishment of three endangered Quercus species. Seedling growth and biomass allocation in Quercus insignis M. Martens & Galeotti, Q. sartorii Liebm. and Q. xalapensis Bonpl. was determined under two light levels: light gap (1338 µmol m-2 s-1 and closed canopy (118 µmol m-2 s-1 in a cloud forest in Veracruz, Mexico. Growth and development were evaluated over the first 13 months. Results suggest there was a significant effect of light conditions on growth rate and biomass allocation. Although survival rate was similar among both environments, the three species showed lower growth rates under the closed canopy during the first nine months, while elongation rate was higher during the last three months under this environment compared to the light gap. Across all species, fresh biomass and dry biomass of roots, stem and leaves were almost 50% higher in light gap than under closed canopy. Q. insignis produced more biomass in shoots and roots than Q. sartorii and Q. xalapensis, which may increase its establishment success in shaded conditions. Results suggest that these three oak species are suited to planting in small gaps, but also in shaded understory conditions, as high early survival (>90% may allow enrichment planting in advance of gap creation.

  1. Variation in Seedling Growth of Tamarindus indica (L.: A Threatening Medicinal Fruit Tree Species in Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Salim Azad

    2014-01-01

    Full Text Available Seedling growth is a precondition for conservation and sustainable use of genetic resources which depends upon understanding of breeding system, genetic inconsistency, and evolutionary forces in forest tree improvement. The aim of this study was to determine variation in seedling growth and age-age correlations of Tamarindus indica at population level in Bangladesh. The study revealed significant (P<0.05 differences of seasonal variation in seedling growth. Height and collar diameter growth showed significant (P<0.05 positive correlation with mean monthly rainfall. The study also revealed significant difference (P<0.05 of seedling growth among T. indica population. PCA illustrated rainfall, height growth, and diameter growth as the main characters in this study which defined drought as an additive character for this species. Cluster analysis of similarity showed how seedlings from 22.67°N latitude (origin separated from others. An increasing trend of age-age correlation was identified in both cases of shoot height and diameter growth. The study concluded that seed collection for either ex situ conservation or seedling production can be done from 22.67°N latitude as seedlings from that area performed better than others, and early clonal selection of T. indica can be done at the age of 9 months.

  2. Anaerobiosis and ethanol effects on germination, growth, and protein synthesis of five Echinochloa species

    International Nuclear Information System (INIS)

    Dybiec, L.D.; Rumpho, M.E.; Kennedy, R.A.

    1989-01-01

    Five Echinochloa species, encompassing a spectrum from flood tolerant to flood intolerant, were studied to determine the mechanisms of anaerobic germination and growth. Seeds were germinated in air or N 2 , plus 0, 1 or 3% ethanol, and germination rates and growth measurements recorded for 7 days. In air or N 2 increasing ethanol levels did not affect total germination per se, although the rate of germination was delayed in N 2 . Shoot/root lengths in air were highest for tolerant species and increased with increasing ethanol, whereas, in intolerant species, shoot/root lengths decreased with increasing ethanol. Aerobic vs. anaerobic polypeptide profiles of each of the species were compared by SDS/PAGE. For all species, the number of polypeptides decreased under anaerobiosis and several quantitative differences were apparent relative to the aerobic profile. In addition, amino acid incorporation into protein was analyzed by [ 35 S]-Met labeling of 3 day old seedlings grown in air or N 2 . Significant protein synthesis was measured in tolerant seedlings under N 2 and several polypeptides were specifically induced. These results are being compared with labeling patterns of the other semi-tolerant and intolerant Echinochloa species to determine their importance in flooding tolerance

  3. Regression analysis of growth responses to water depth in three wetland plant species

    DEFF Research Database (Denmark)

    Sorrell, Brian K; Tanner, Chris C; Brix, Hans

    2012-01-01

    ) differing in depth preferences in wetlands, using non-linear and quantile regression analyses to establish how flooding tolerance can explain field zonation. Methodology Plants were established for 8 months in outdoor cultures in waterlogged soil without standing water, and then randomly allocated to water...... depths from 0 – 0.5 m. Morphological and growth responses to depth were followed for 54 days before harvest, and then analysed by repeated measures analysis of covariance, and non-linear and quantile regression analysis (QRA), to compare flooding tolerances. Principal results Growth responses to depth...... differed between the three species, and were non-linear. P. tenax growth rapidly decreased in standing water > 0.25 m depth, C. secta growth increased initially with depth but then decreased at depths > 0.30 m, accompanied by increased shoot height and decreased shoot density, and T. orientalis...

  4. The effect of temperature on growth and competition between Sphagnum species.

    Science.gov (United States)

    Breeuwer, Angela; Heijmans, Monique M P D; Robroek, Bjorn J M; Berendse, Frank

    2008-05-01

    Peat bogs play a large role in the global sequestration of C, and are often dominated by different Sphagnum species. Therefore, it is crucial to understand how Sphagnum vegetation in peat bogs will respond to global warming. We performed a greenhouse experiment to study the effect of four temperature treatments (11.2, 14.7, 18.0 and 21.4 degrees C) on the growth of four Sphagnum species: S. fuscum and S. balticum from a site in northern Sweden and S. magellanicum and S. cuspidatum from a site in southern Sweden. In addition, three combinations of these species were made to study the effect of temperature on competition. We found that all species increased their height increment and biomass production with an increase in temperature, while bulk densities were lower at higher temperatures. The hollow species S. cuspidatum was the least responsive species, whereas the hummock species S. fuscum increased biomass production 13-fold from the lowest to the highest temperature treatment in monocultures. Nutrient concentrations were higher at higher temperatures, especially N concentrations of S. fuscum and S. balticum increased compared to field values. Competition between S. cuspidatum and S. magellanicum was not influenced by temperature. The mixtures of S. balticum with S. fuscum and S. balticum with S. magellanicum showed that S. balticum was the stronger competitor, but it lost competitive advantage in the highest temperature treatment. These findings suggest that species abundances will shift in response to global warming, particularly at northern sites where hollow species will lose competitive strength relative to hummock species and southern species.

  5. Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

    Science.gov (United States)

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

  6. Growth responses of maritime sand dune plant species to arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Mariusz Tadych

    2014-08-01

    Full Text Available In a pot experiment conducted in a greenhouse, the response of 6 plant species dominating in the succession of vegetation of a deflation hollow of the Łeba Bar to inoculation with arbuscular mycorrhizal fungi (AMF was investigated. The inoculum was a mixture of soil, roots and spores of 5 species of AMF with the dominant species Glomus aggregatum. Except for Corynephorus canescens and Festuca rubra subsp. arenaria, both the growth and the dry matter of above-ground parts of plants of Agrostis stolonifera, Ammophila arenaria, Corynephorus canescens, Juncus articulatus and J. balticus inoculated with AMF were higher than those growing in soils lacking infection propagules of these fungi. Inoculation with AMF decreased the dry matter of root: shoot ratios in 5 plant species. This property was not determined in Festuca rubra subsp. arenaria due to the death of all control plants. The level of mycorrhizal infection was low and did not correlate with the growth responses found. The high growth reaction of Juncus spp. to AMF found in this study suggests that the opinion of non-mycotrophy or low dependence of plants of Juncaceae on AMF was based on results of investigations of plants growing in wet sites known to inhibit the formation of mycorrhizae.

  7. Modelling planktic foraminifer growth and distribution using an ecophysiological multi-species approach

    Directory of Open Access Journals (Sweden)

    F. Lombard

    2011-04-01

    Full Text Available We present an eco-physiological model reproducing the growth of eight foraminifer species (Neogloboquadrina pachyderma, Neogloboquadrina incompta, Neogloboquadrina dutertrei, Globigerina bulloides, Globigerinoides ruber, Globigerinoides sacculifer, Globigerinella siphonifera and Orbulina universa. By using the main physiological rates of foraminifers (nutrition, respiration, symbiotic photosynthesis, this model estimates their growth as a function of temperature, light availability, and food concentration. Model parameters are directly derived or calibrated from experimental observations and only the influence of food concentration (estimated via Chlorophyll-a concentration was calibrated against field observations. Growth rates estimated from the model show positive correlation with observed abundance from plankton net data suggesting close coupling between individual growth and population abundance. This observation was used to directly estimate potential abundance from the model-derived growth. Using satellite data, the model simulate the dominant foraminifer species with a 70.5% efficiency when compared to a data set of 576 field observations worldwide. Using outputs of a biogeochemical model of the global ocean (PISCES instead of satellite images as forcing variables gives also good results, but with lower efficiency (58.9%. Compared to core tops observations, the model also correctly reproduces the relative worldwide abundance and the diversity of the eight species when using either satellite data either PISCES results. This model allows prediction of the season and water depth at which each species has its maximum abundance potential. This offers promising perspectives for both an improved quantification of paleoceanographic reconstructions and for a better understanding of the foraminiferal role in the marine carbon cycle.

  8. Species-specific effects of woody litter on seedling emergence and growth of herbaceous plants.

    Directory of Open Access Journals (Sweden)

    Kadri Koorem

    Full Text Available The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest--evergreen spruce (Picea abies, deciduous hazel (Corylus avellana, and a mixture of the two species--and litter amount--shallow (4 mm, deep (12 mm and leachate--on seedling emergence and biomass of three understorey species. The effect of litter amount on seedling emergence was highly dependent on litter type; while spruce needle litter had a significant negative effect that increased with depth, seedling emergence in the presence of hazel broadleaf litter did not differ from control pots containing no litter. Mixed litter of both species also had a negative effect on seedling emergence that was intermediate compared to the single-species treatments. Spruce litter had a marginally positive (shallow or neutral effect (deep on seedling biomass, while hazel and mixed litter treatments had significant positive effects on biomass that increased with depth. We found non-additive effects of litter mixtures on seedling biomass indicating that high quality hazel litter can reduce the negative effects of spruce. Hazel litter does not inhibit seedling emergence; it increases seedling growth, and creates better conditions for seedling growth in mixtures by reducing the suppressive effect of spruce litter, having a positive effect on understorey species richness.

  9. The plant economics spectrum is structured by leaf habits and growth forms across subtropical species.

    Science.gov (United States)

    Zhao, Yan-Tao; Ali, Arshad; Yan, En-Rong

    2017-02-01

    The plant economics spectrum that integrates the combination of leaf and wood syndromes provides a useful framework for the examination of species strategies at the whole-plant level. However, it remains unclear how species that differ in leaf habits and growth forms are integrated within the plant economics spectrum in subtropical forests. We measured five leaf and six wood traits across 58 subtropical plant species, which represented two leaf habits (evergreen vs deciduous) and two growth forms (tree vs shrub) in eastern China. Principal component analysis (PCA) was employed separately to construct the leaf (LES), wood (WES) and whole-plant (WPES) economics spectra. Leaf and wood traits are highly intra- and intercorrelated, thus defining not only the LES and WES, but also a WPES. Multi-trait variations in PCAs revealed that the traits which were representative of the acquisitive strategy, i.e., cheap tissue investment and rapid returns on that investment, were clustered at one end, while traits that represented the conservative strategy, i.e., expensive tissue investment and slower returns, were clustered at other end in each of the axes of the leaf and wood syndromes (PC1-axis) and the plant height strategy (PC2-axis). The local WPES, LES and WES were tightly correlated with each other. Evergreens shaped the conservative side, while deciduous species structured the acquisitive side of the WPES and LES. With respect to plant height strategies, trees formulated the acquisitive side and shrub species made up the conservative side of the WPES, LES and WES. In conclusion, our results suggested that the LES and WES were coordinated to a WPES for subtropical species. The finding of this local spectrum of plant form and function would be beneficial for modeling nutrient fluxes and species compositions in the changing climate, but also for understanding species strategies in an evolutionary context. © The Author 2016. Published by Oxford University Press. All rights

  10. Chick metabolic rate and growth in three species of albatross: a comparative study.

    Science.gov (United States)

    Phillips, R A; Green, J A; Phalan, B; Croxall, J P; Butler, P J

    2003-05-01

    The relative importance of genetic vs. environmental factors in determining the pattern of avian post-embryonic development is much debated. Previous cross-fostering of albatrosses suggested that although inter-specific variation in growth rate was determined primarily by differences in dietary energy content, species-specific constraints might have evolved that could limit maximal growth, even in chicks fed at similar rates and on similar diets. This study aimed to determine whether intrinsic differences in resting metabolic rate were apparent during the linear phase of growth in chicks of three species (black-browed, grey-headed and light-mantled sooty albatrosses). There was a gradual increase in absolute, and a reduction in mass-specific metabolic rate from 5.0 W kg(-1) during the earliest part of linear growth, to 3.5 W kg(-1) by the time chicks reached peak mass. These values are considerably higher than in resting adults of comparable or lower mass, presumably reflecting the large size and high metabolic demand of organs involved in rapid nutrient processing and tissue synthesis by chicks. The lack of any detectable inter-specific variation in the pattern of metabolic rate changes casts some doubt on the existence of fundamental differences in growth rate that cannot be attributed simply to differences in dietary energy or nutrient delivery rate.

  11. Bacillus species enhance growth parameters of chickpea (Cicer arietinum L.) in chromium stressed soils.

    Science.gov (United States)

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2010-11-01

    Pollution of the agricultural land by the toxic chromium is a global threat that has accelerated dramatically since the beginning of industrial revolution. Toxic chromium affects both the microbial diversity as well as reduces the growth of the plants. Understanding the effect of the chromium reducing and plant growth promoting rhizobacteria on chickpea crop will be useful. Chromium reducing and plant growth promoting Bacillus species PSB10 significantly improved growth, nodulation, chlorophyll, leghaemoglobin, seed yield and grain protein of chickpea crop grown in the presence of different concentrations of chromium compared to the plants grown in the absence of bio-inoculant. The strain also reduced the uptake of chromium in roots, shoots and grains of chickpea crop compared to plants grown in the absence of bio-inoculant. This study thus suggested that the Bacillus species PSB10 due to its intrinsic abilities of growth promotion and attenuation of the toxic effects of chromium could be exploited for remediation of chromium from chromium contaminated sites. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Selection for life-history traits to maximize population growth in an invasive marine species

    DEFF Research Database (Denmark)

    Jaspers, Cornelia; Marty, Lise; Kiørboe, Thomas

    2018-01-01

    Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life-history features characteristic for r-selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r......) in invaded habitats. Here, we demonstrate substantially earlier maturation at a 2 orders of magnitude lower body mass at first reproduction in invasive compared to native populations of the comb jelly Mnemiopsis leidyi. Empirical results are corroborated by a theoretical model for competing life...... populations is an underappreciated determinant of invasiveness, acting as substrate upon which selection can act during the invasion process....

  13. Modelling planktic foraminifer growth and distribution using an ecophysiological multi-species approach

    DEFF Research Database (Denmark)

    Lombard, Fabien; Labeyrie, L.; Michel, E.

    2011-01-01

    the influence of food concentration (estimated via Chlorophyll-a concentration) was calibrated against field observations. Growth rates estimated from the model show positive correlation with observed abundance from plankton net data suggesting close coupling between individual growth and population abundance...... ocean (PISCES) instead of satellite images as forcing variables gives also good results, but with lower efficiency (58.9%). Compared to core tops observations, the model also correctly reproduces the relative worldwide abundance and the diversity of the eight species when using either satellite data...

  14. Growth characteristics and nutrient content of some herbaceous species under shade and fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Koukoura, Z.; Kyriazopoulos, A. P.; Parissi, Z. M.

    2009-07-01

    Herbage production and nutrient content are affected by light interception and soil fertility. The objective of this study was to assess the effects of artificial shade and fertilization on herbage production, growth characteristics, and nutrient content of the grass species Dactylis glomerata and Festuca ovina, and the legume species Trifolium subterraneum and Medicago lupulina. Each plant species was placed under three shading treatments of 90% (heavy shade), 50% (moderate shade) and 0% (control). Fertilization (225 kg ha{sup -}1 N, 450 kg ha{sup -}1 P, and 225 kg ha{sup -}1 K) was applied to half of the pots of every species and shading treatment. Reduced light intensity (90% shading) significantly lowered herbage production from 18% for F. ovina to 48% for D. glomerata and decreased the root:shoot (R/S) ratio of all species but the moderate reduction of light intensity (50%) did not affect R/S ratio and herbage production of the grasses and M. lupulina, while it resulted in an increase of the production of T. subterraneum by 10.5%. Reduced light intensity increased by 25% on average, the crude protein concentration of the grass species while moderate shading did not affect the crude protein concentration of T. subterraneum. Fertilization increased herbage production from 16% for F. ovina to 59% for D. glomerata and ameliorated its nutrient content. Among the tested species, D. glomerata and T. subterraneum demonstrated the highest shade tolerance and could be incorporated into silvopastoral systems of the Mediterranean region. (Author)

  15. The impact of annual and seasonal rainfall patterns on growth and phenology of emergent tree species in Southeastern Amazonia, Brazil

    Science.gov (United States)

    James Grogan; Mark Schulze

    2012-01-01

    Understanding tree growth in response to rainfall distribution is critical to predicting forest and species population responses to climate change. We investigated inter-annual and seasonal variation in stem diameter by three emergent tree species in a seasonally dry tropical forest in southeast Pará, Brazil. Annual diameter growth rates by Swietenia macrophylla...

  16. Allelopathy in two species of Chenopodium -inhibition of germination and seedling growth of certain weeds

    Directory of Open Access Journals (Sweden)

    Subhash C. Datta

    2014-01-01

    Full Text Available The activity of washed leaf and inflorescence material of Chenopodium ambrosioides and C. murale, decaying leaves and inflorescences, and field soils collected beneath Chenopodium plants were examined in terms of the inhibition of seed germination and seedling growth of five weeds, viz. Abutilon indicum, Cassia sophera var. purpurea, C. tora, Evolvulus numularius and Tephrosia hamiltonii. The allelopathic pattern varied in each of the two test species and this depended on the type of test matter. However, the germination as well as the root and hypocotyl growth of A. indicum and E. nummularius were more hampered by phytotoxins or inhibitors from Chenopodium than were the other weeds. Since the leaf and inflorescence of Chenopodium formed the source of inhibitors, the respective plant-parts from the two species were chemically analysed and the presence of three terpenes (p-cymene, ascaridole and aritazone from C. ambrosioides and an organic acid (oxalic acid from C. murale were implicated in the allelopathic effect.

  17. Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, P.J.

    2001-09-04

    This numeric data package provides data sets, and accompanying documentation, on site characterization, system performance, weather, species composition, and growth for the Throughfall Displacement Experiment, which was established in the Walker Branch Watershed of East Tennessee to provide data on the responses of forests to altered precipitation regimes. The specific data sets include soil water content and potential, coarse fraction of the soil profile, litter layer temperature, soil temperature, monthly weather, daily weather, hourly weather, species composition of trees and saplings, mature tree and sapling annual growth, and relative leaf area index. Fortran and SAS{trademark} access codes are provided to read the ASCII data files. The data files and this documentation are available without charge on a variety of media and via the Internet from the Carbon Dioxide Information Analysis Center (CDIAC).

  18. Growth promotion of Lactuca sativa in response to volatile organic compounds emitted from diverse bacterial species.

    Science.gov (United States)

    Fincheira, Paola; Venthur, Herbert; Mutis, Ana; Parada, Maribel; Quiroz, Andrés

    2016-12-01

    Agrochemicals are currently used in horticulture to increase crop production. Nevertheless, their indiscriminate use is a relevant issue for environmental and legal aspects. Alternative tools for reducing fertilizers and synthetic phytohormones are being investigated, such as the use of volatile organic compounds (VOCs) as growth inducers. Some soil bacteria, such as Pseudomonas and Bacillus, stimulate Arabidopsis and tobacco growth by releasing VOCs, but their effects on vegetables have not been investigated. Lactuca sativa was used as model vegetable to investigate bacterial VOCs as growth inducers. We selected 10 bacteria strains, belonging to Bacillus, Staphylococcus and Serratia genera that are able to produce 3-hydroxy-2-butanone (acetoin), a compound with proven growth promoting activity. Two-day old-seedlings of L. sativa were exposed to VOCs emitted by the selected bacteria grown in different media cultures for 7 days. The results showed that the VOCs released from the bacteria elicited an increase in the number of lateral roots, dry weight, root growth and shoot length, depending on the media used. Three Bacillus strains, BCT53, BCT9 and BCT4, were selected according to its their growth inducing capacity. The BCT9 strain elicited the greatest increases in dry weight and primary root length when L. sativa seedlings were subjected to a 10-day experiment. Finally, because acetoin only stimulated root growth, we suggest that other volatiles could be responsible for the growth promotion of L. sativa. In conclusion, our results strongly suggest that bacteria volatiles can be used as growth-inducers as alternative or complementary strategies for application in horticulture species. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. High plant species diversity indirectly mitigates CO 2- and N-induced effects on grasshopper growth

    Science.gov (United States)

    Strengbom, Joachim; Reich, Peter B.; Ritchie, Mark E.

    2008-09-01

    We examined how elevated atmospheric [CO 2] and higher rate of nitrogen (N) input may influence grasshopper growth by changing food plant quality and how such effects may be modified by species diversity of the plant community. We reared grasshopper nymphs ( Melanoplus femurrubrum) on Poa pratensis from field-grown monocultures or polycultures (16 species) that were subjected to either ambient or elevated levels of CO 2 and N. Grasshopper growth rate was higher on P. pratensis leaves grown in monocultures than in polycultures, higher on P. pratensis grown under elevated than under ambient [CO 2], and higher on P. pratensis grown under elevated than under ambient [N]. The higher growth rate observed on P. pratensis exposed to elevated [CO 2] was, however, less pronounced for polyculture- than monoculture-grown P. pratensis. Growth rate of the grasshoppers was positively correlated with leaf [N], [C], and concentration of soluble carbohydrates + lipids. Concentration of non-structural carbohydrates + lipids was higher in leaves grown under elevated than under ambient [CO 2], and the difference between P. pratensis grown under ambient and elevated [CO 2] was greater for monoculture- than polyculture-grown P. pratensis. In addition, leaf N concentration was higher in P. pratensis grown in monocultures than in polycultures, suggesting that plant species richness, indirectly, may influence insect performance by changed nutritional value of the plants. Because we found interactive effects between all factors included ([CO 2], [N], and plant species diversity), our results suggest that these parameters may influence plant-insect interactions in a complex way that is not predictable from the sum of single factor manipulations.

  20. Studies on the effects on growth and antioxidant responses of two marine microalgal species to uniconazole

    Science.gov (United States)

    Mei, Xueqiao; Zheng, Kang; Wang, Lingdong; Li, Yantuan

    2014-10-01

    Uniconazole, as a plant growth retardant, can enhance stress tolerance in plants, possibly because of improved antioxidation defense mechanisms with higher activities of superoxide dismutase (SOD) and peroxidase (POD) enzymes that retard lipid peroxidation and membrane deterioration. These years much attention has been focused on the responses of antioxidant system in plants to uniconazole stress, but such studies on aquatic organism are very few. Moreover, no information is available on growth and antioxidant response in marine microalgae to uniconazole. In this paper, the growth and antioxidant responses of two marine microalgal species, Platymonas helgolandica and Pavlova viridis, at six uniconazole concentrations (0-15 mg L-1) were investigated. The results demonstrated that 3 mg L-1 uniconazole could increase significantly chlorophyll a and carbohydrate contents of P. helgolandica ( P catalase (CAT) were enhanced remarkably at low concentrations of uniconazole. However, significant reduction of SOD and CAT activities was observed at higher concentrations of uniconazole.

  1. Changing leaf litter feedbacks on plant production across contrasting sub-arctic peatland species and growth forms.

    NARCIS (Netherlands)

    Dorrepaal, E.; Cornelissen, J.H.C.; Aerts, R.

    2007-01-01

    Plant species and growth forms differ widely in litter chemistry, which affects decay and may have important consequences for plant growth via e.g. the release of nutrients and growth-inhibitory compounds. We investigated the overall short-term (9.5 months) and medium-term (21.5 months) feedback

  2. Planting density and initial growth of two tree species adapted to the semi-arid region

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2012-10-01

    Full Text Available Planting densities influence several aspects of forest formation, including management practices, timber yield, quality, and extraction, and consequently its production costs. The objective of this study was to evaluate Mimosa caesalpiinifolia and Gliricidia sepium growth as a function of planting density (400, 600, 800, 1000, and 1200 plants ha-1 and plant age. The species were evaluated every 90 days for plant height (PH, crown diameter (CD and root collar diameter (RCD (10 cm above the ground, with the first evaluation performed at 90 days and the last at 720 days. When plants were one year of age and beyond, evaluations were conducted also for stem diameter at breast height (DBH (1.30 m above the ground. A randomized block design with split-plots and three replicates was adopted. Species were assigned to plots, planting densities were assigned to subplots, and evaluation ages were assigned to subsubplots. The four traits in both species had their values decreased as planting density increased, but continually increased as plant age increased. For PH and RCD there was an alternation between species superiority, with gliricidia being superior to sabiá at some ages, while the opposite occurred at other ages. As to CD the species only differed in the last measurement, gliricidia being superior. With regard to DBH, gliricidia was superior starting from the second measurement. There was an effect of the species × ages interaction for the four traits and also an effect of the densities × ages interaction for CD and DBH.

  3. The effects of ultraviolet radiation on growth and bleaching in three species of Hawaiian coral

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, G.D. (California State Univ., Long Beach (United States))

    1990-01-09

    Long term exposure to ultraviolet radiation is harmful to many organisms, including hermatypic corals, which obtain much of their nutrition from photosynthetic zooxanthellae. Therefore, increased UV radiation from atmospheric ozone depletion could inhibit growth of such corals. Moreover, coral bleaching, which has been attributed to loss of pigment and/or expulsion of zooxanthellae, may be a specific response to UV light. Does UV-A reduce skeletal growth or influence population density and pigment content of zooxanthellae In addition, do zooxanthellae migrate to shaded areas of the colony to avoid ultraviolet light Using alizarin red stain and suitable filters, I compared the stain and suitable filters, I compared the effects of UV-A (320-400nm) and full-spectrum UV (280-400nm) on the skeletal growth of two Hawaiian corals, Montipora verrucosa, Pocillopora damicornis, in situ. In the perforate corals, M. Verrucosa and Porites compressa, I measured concentration of zooxanthellae and their chlorophyll content to quantify bleaching in response to UV light. Reduction in skeletal growth by the two corals in response to different ranges of UV light appears to be species specific. Bleaching by UV appears to be characterized by an initial loss of pigment followed by the expulsion and migration of the zooxanthellae to shaded areas of the colony. Differences in tolerance and adaptation to decreasing ozone levels and increasing UV light should confer a competitive advantage on various species and morphologies of reef-building corals.

  4. Nickel detoxification and plant growth promotion by multi metal resistant plant growth promoting Rhizobium species RL9.

    Science.gov (United States)

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2013-07-01

    Pollution of the biosphere by heavy metals is a global threat that has accelerated dramatically since the beginning of industrial revolution. The aim of the study is to check the resistance of RL9 towards the metals and to observe the effect of Rhizobium species on growth, pigment content, protein and nickel uptake by lentil in the presence and absence of nickel. The multi metal tolerant and plant growth promoting Rhizobium strain RL9 was isolated from the nodules of lentil. The strain not only tolerated nickel but was also tolerant o cadmium, chromium, nickel, lead, zinc and copper. The strain tolerated nickel 500 μg/mL, cadmium 300 μg/mL, chromium 400 μg/mL, lead 1,400 μg/mL, zinc 1,000 μg/mL and copper 300 μg/mL, produced good amount of indole acetic acid and was also positive for siderophore, hydrogen cyanide and ammonia. The strain RL9 was further assessed with increasing concentrations of nickel when lentil was used as a test crop. The strain RL9 significantly increased growth, nodulation, chlorophyll, leghaemoglobin, nitrogen content, seed protein and seed yield compared to plants grown in the absence of bioinoculant but amended with nickel The strain RL9 decreased uptake of nickel in lentil compared to plants grown in the absence of bio-inoculant. Due to these intrinsic abilities strain RL9 could be utilized for growth promotion as well as for the remediation of nickel in nickel contaminated soil.

  5. Growth of tropical tree species and absorption of copper in soil artificially contaminated.

    Science.gov (United States)

    Silva, R F; Andreazza, R; Da Ros, C; Dellai, A; Jacques, R J S; Scheid, D

    2015-11-01

    Reclamation of copper contaminated sites using forest species may be an efficient alternative to reduce the negative impact. The aim of this study was to quantify the growth and evaluate the quality of seedlings of native species at different doses of copper in the soil. The experimental design was completely randomized, with seven replications in a factorial arrangement (3×9), using three indigenous species of plants (Anadenanthera macrocarpa, Mimosa scabrella and Apuleia leiocarpa) and nine doses of copper in the soil (0, 60, 120, 180, 240, 300, 360, 420 and 480 mg kg-1).The experiment was carried out in a greenhouse which the seedlings were grown for 180 days. The experimental units were plastic pots of 125 cm3 filled with Oxisol. The results indicated that the levels of copper applied to the soil decreased the quality of seedlings and growth of Apuleia leiocarpato a lesser extent compared with Mimosa scabrella and Anadenanthera macrocarpa. Anadenanthera macrocarpa was the forest species that resulted in the lowest copper translocation from roots to shoots. In addition, the Apuleia leiocarpa exhibited high resistance and tolerance for copper in the soil and also, it is highlighted an ability for copper phytoremediation.

  6. Growth of tropical tree species and absorption of copper in soil artificially contaminated

    Directory of Open Access Journals (Sweden)

    R. F. Silva

    Full Text Available Abstract Reclamation of copper contaminated sites using forest species may be an efficient alternative to reduce the negative impact. The aim of this study was to quantify the growth and evaluate the quality of seedlings of native species at different doses of copper in the soil. The experimental design was completely randomized, with seven replications in a factorial arrangement (3×9, using three indigenous species of plants (Anadenanthera macrocarpa, Mimosa scabrella and Apuleia leiocarpa and nine doses of copper in the soil (0, 60, 120, 180, 240, 300, 360, 420 and 480 mg kg–1.The experiment was carried out in a greenhouse which the seedlings were grown for 180 days. The experimental units were plastic pots of 125 cm3 filled with Oxisol. The results indicated that the levels of copper applied to the soil decreased the quality of seedlings and growth of Apuleia leiocarpato a lesser extent compared with Mimosa scabrella and Anadenanthera macrocarpa. Anadenanthera macrocarpa was the forest species that resulted in the lowest copper translocation from roots to shoots. In addition, the Apuleia leiocarpa exhibited high resistance and tolerance for copper in the soil and also, it is highlighted an ability for copper phytoremediation.

  7. Effects of diesel and kerosene on germination and growth of coastal wetland plant species.

    Science.gov (United States)

    Kim, Kee Dae

    2014-11-01

    This study aims to investigate effects of diesel and kerosene on seed germination and seedling growth among coastal wetland plants to select species that can be used for the restoration and revegetation of oil-polluted habitats. Tests on 51 species were performed in Petri dishes containing 0 %, 6 %, 12 %, and 18 % diesel, 20 %, 40 %, and 60 % kerosene; each treatment combination was replicated five times with 20 seeds in each Petri dish. All dishes were held in a growth chamber with 20°C day of 12 h/15°C night of 12 h in 80 % humidity for 20 days for calculating the germination percentage, seedling weight, and seedling vitality. The germination percentage of Rumex stenophyllus decreased significantly in diesel and kerosene treatments. The weights of seedlings treated with diesel and kerosene either increased or decreased in comparison with controls depending on the species. Vitality percentage values were high for seedlings of Chenopodium ficifolium. Thus, herbaceous plant responses to oil treatments are species-specific.

  8. The role of mobile small RNA species during root growth and development.

    Science.gov (United States)

    Furuta, Kaori; Lichtenberger, Raffael; Helariutta, Ykä

    2012-04-01

    In animals and plants, small RNAs have been identified as important regulatory factors controlling cell fate. A bidirectional cell-to-cell communication involving the mobile transcription factor SHR and microRNA165/166 species specifies the radial position of two types of xylem vessels in Arabidopsis roots. The microRNAs provide short-range non-cell-autonomous developmental signals that are transported through the plasmodesmata (PD) via the symplastic pathway. 21-24 nucleotide-long small RNA species have been shown to move from the shoot to the root. In this review, we highlight the presence of small RNA species as an emerging class of important mobile signals associated with the growth and development of the root. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Aggressiveness of Fusarium species and impact of root infection on growth and yield of soybeans.

    Science.gov (United States)

    Arias, María M Díaz; Leandro, Leonor F; Munkvold, Gary P

    2013-08-01

    Fusarium spp. are commonly isolated from soybean roots but the pathogenic activity of most species is poorly documented. Aggressiveness and yield impact of nine species of Fusarium were determined on soybean in greenhouse (50 isolates) and field microplot (19 isolates) experiments. Root rot severity and shoot and root dry weights were compared at growth stages V3 or R1. Root systems were scanned and digital image analysis was conducted; yield was measured in microplots. Disease severity and root morphology impacts varied among and within species. Fusarium graminearum was highly aggressive (root rot severity >90%), followed by F. proliferatum and F. virguliforme. Significant variation in damping-off (20 to 75%) and root rot severity (60%) was observed among F. oxysporum isolates. In artificially-infested microplots, root rot severity was low (soybean at different plant stages and introduces root image analysis to assess the impact of root pathogens on soybean.

  10. Seedling growth responses to light and mineral N form are predicted by species ecologies and can help explain tree diversity

    Science.gov (United States)

    Michael B. Walters; John L. Willis; Kurt W. Gottschalk

    2014-01-01

    Tree species distributions and diversity could be explained by rank changes in performance over multiple spatiotemporal resource gradients, i.e., resource partitioning. For 14 species planted in 45 harvest gap and closed canopy locations in a mesic northern hardwood forest community, Michigan, USA, we asked the following questions: (i) are species growth responses to...

  11. Phytotoxic Activity of Ocimum tenuiflorum Extracts on Germination and Seedling Growth of Different Plant Species

    Directory of Open Access Journals (Sweden)

    A. K. M. Mominul Islam

    2014-01-01

    Full Text Available Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum, lettuce (Lactuca sativa, alfalfa (Medicago sativa, Italian ryegrass (Lolium multiflorum, barnyard grass (Echinochloa crus-galli, and timothy (Phleum pratense at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1 reduced significantly the total germination percent (GP, germination index (GI, germination energy (GE, speed of emergence (SE, seedling vigour index (SVI, and coefficient of the rate of germination (CRG of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50 and mean germination time (MGT were increased at the same or higher than this concentration. The increasing trend of T50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. The I50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds.

  12. Thermal Responses of Growth and Toxin Production in Four Prorocentrum Species from the Central Red Sea

    KAUST Repository

    Aynousah, Arwa

    2017-06-01

    Harmful algae studies, in particular toxic dinoflagellates, and their response to global warming in the Red Sea are still limited. This study was aimed to be the first to characterize the identity, thermal responses and toxin production of four Prorocentrum strains isolated from the Central Red Sea, Saudi Arabia. Morphological and molecular phylogenetic analysis identified the strains as P. elegans, P. rhathymum and P. emarginatum. However, the identity of strain P. sp.6 is currently unresolved, albeit sharing close affinity with P. leve. Growth experiments showed that all species could grow at 24-32°C, but only P. sp.6 survived the 34°C treatment. The optimum temperatures (Topt) estimated from the Gaussian model corresponded to 27.17, 29.33, 26.87, and 27.64°C for P. sp.6, P. elegans, P. rhathymum and P. emarginatum, respectively. However, some discrepancy with the Topt derived from the growth performance were observed for P. elegans and P. emarginatum, as thermal responses differed from the typical Gaussian fit. The Prorocentrum species examined showed a sharp decrease after the optimum temperature resulting in very high activation energies for the fall slope, especially for P. elegans and P. emarginatum. The minimum critical temperature limit for growth was not detected within the range of temperatures examined. Subsequently, high performance liquid chromatography coupled with mass spectrometry (HPLC-MS) analysis revealed all species as non okadaic acid (OA, common toxin of the Prorocentrum genus) producers at any temperature treatment. However, other forms of toxin (i.e. fast acting toxins) not examined here could be produced. Therefore, further investigations are required. The results of this study provided significant contribution to our knowledge regarding the presence, thermal response and toxin production of four Prorocentrum species from the Central Red Sea, Saudi Arabia.

  13. The Effects of Salinity on Growth and Distribution of Four Freshwater Diatom Species

    International Nuclear Information System (INIS)

    Hayati, Attayeb A

    2007-01-01

    The upper and lower salinity limits of Nitzschia acicularis, Nitzschia pusilla, Nitzschia palea and Synedra acus, which were isolated from the Damour River, Lebanon, were determined from laboratory cultures. Growth responses of the investigated diatoms showed maximum growth in the enriched Damour River natural water (salinity = 0.24 ppt). With an increase in salinity there was a gradual decrease in the growth until the upper limit was reached. At higher salt concentrations near the upper limit a lag phase was observed, during the first two days of the growing culture, where the growth was greatly declined. This reduction in growth can be attributed to high osmotic stress experienced by the investigated diatoms when transferred to flasks containing salinities near the extremes of their tolerance. The investigated diatoms appear to be very resistant and capable of adaptation to new situations because they grew better after this two days lag period. The results of this study also showed that all the investigated diatom species have broader salinity tolerance limits than those reported in the literature and this would enable their distribution at localities with higher or lower salinities than those typical of the Damour River, Lebanon. (author)

  14. Reactive oxygen species are involved in BMP-induced dendritic growth in cultured rat sympathetic neurons.

    Science.gov (United States)

    Chandrasekaran, Vidya; Lea, Charlotte; Sosa, Jose Carlo; Higgins, Dennis; Lein, Pamela J

    2015-07-01

    Previous studies have shown that bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, the downstream signaling molecules that mediate the dendrite promoting activity of BMPs are not well characterized. Here we test the hypothesis that reactive oxygen species (ROS)-mediated signaling links BMP receptor activation to dendritic growth. In cultured rat sympathetic neurons, exposure to any of the three mechanistically distinct antioxidants, diphenylene iodinium (DPI), nordihydroguaiaretic acid (NGA) or desferroxamine (DFO), blocked de novo BMP-induced dendritic growth. Addition of DPI to cultures previously induced with BMP to extend dendrites caused dendritic retraction while DFO and NGA prevented further growth of dendrites. The inhibition of the dendrite promoting activity of BMPs by antioxidants was concentration-dependent and occurred without altering axonal growth or neuronal cell survival. Antioxidant treatment did not block BMP activation of SMAD 1,5 as determined by nuclear localization of these SMADs. While BMP treatment did not cause a detectable increase in intracellular ROS in cultured sympathetic neurons as assessed using fluorescent indicator dyes, BMP treatment increased the oxygen consumption rate in cultured sympathetic neurons as determined using the Seahorse XF24 Analyzer, suggesting increased mitochondrial activity. In addition, BMPs upregulated expression of NADPH oxidase 2 (NOX2) and either pharmacological inhibition or siRNA knockdown of NOX2 significantly decreased BMP-7 induced dendritic growth. Collectively, these data support the hypothesis that ROS are involved in the downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that ROS-mediated signaling positively modulates dendritic complexity in peripheral neurons. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Growth inhibitory activity of extracts and compounds from Cimicifuga species on human breast cancer cells.

    Science.gov (United States)

    Einbond, Linda Saxe; Wen-Cai, Ye; He, Kan; Wu, Hsan-au; Cruz, Erica; Roller, Marc; Kronenberg, Fredi

    2008-06-01

    The purpose of this report is to explore the growth inhibitory effect of extracts and compounds from black cohosh and related Cimicifuga species on human breast cancer cells and to determine the nature of the active components. Black cohosh fractions enriched for triterpene glycosides and purified components from black cohosh and related Asian species were tested for growth inhibition of the ER(-) Her2 overexpressing human breast cancer cell line MDA-MB-453. Growth inhibitory activity was assayed using the Coulter Counter, MTT and colony formation assays. Results suggested that the growth inhibitory activity of black cohosh extracts appears to be related to their triterpene glycoside composition. The most potent Cimicifuga component tested was 25-acetyl-7,8-didehydrocimigenol 3-O-beta-d-xylopyranoside, which has an acetyl group at position C-25. It had an IC(50) of 3.2microg/ml (5microM) compared to 7.2microg/ml (12.1microM) for the parent compound 7,8-didehydrocimigenol 3-O-beta-d-xylopyranoside. Thus, the acetyl group at position C-25 enhances growth inhibitory activity. The purified triterpene glycoside actein (beta-d-xylopyranoside), with an IC(50) equal to 5.7microg/ml (8.4microM), exhibited activity comparable to cimigenol 3-O-beta-d-xyloside. MCF7 (ER(+)Her2 low) cells transfected for Her2 are more sensitive than the parental MCF7 cells to the growth inhibitory effects of actein from black cohosh, indicating that Her2 plays a role in the action of actein. The effect of actein on Her2 overexpressing MDA-MB-453 and MCF7 (ER(+)Her2 low) human breast cancer cells was examined by fluorescent microscopy. Treatment with actein altered the distribution of actin filaments and induced apoptosis in these cells. These findings, coupled with our previous evidence that treatment with the triterpene glycoside actein induced a stress response and apoptosis in human breast cancer cells, suggest that compounds from Cimicifuga species may be useful in the prevention and

  16. Fungitoxicity of organic extracts of Ocimum basilicum on growth and morphogenesis of Bipolaris species (teleomorph Cochliobolus).

    Science.gov (United States)

    Elsherbiny, E A; Safwat, N A; Elaasser, M M

    2017-10-01

    This study aimed at evaluating the inhibitory effects of various organic extracts of Ocimum basilicum against some species of Bipolaris and Cochliobolus with GC-MS and HPLC analysis. The ethyl acetate extract consisted of methyl cinnamate as the most abundant component, while butylated hydroxytoluene was the major component in the methanol extract. Pyrogallol and chlorogenic acid were major phenolic compounds in the ethyl acetate and methanol extracts, respectively. Complete growth inhibition of all fungi except Cochliobolus australiensis was observed by ethyl acetate extract, and on Bipolaris hawaiensis, Bipolaris spicifera and Cochliobolus cynodontis by methanol extract. Spore germination was completely inhibited for Bipolaris hawaiensis by ethyl acetate extract. Scanning electron microscopic observations revealed that the organic extracts cause considerable morphological changes of the fungal hyphae such as mycelial asymmetry, hyphal swelling, sunken, curling, distorted and broken hyphae. The ethyl acetate and methanol extracts of O. basilicum can result in an effective suppression of mycelial growth, spore germination and germ tube elongation of Bipolaris and Cochliobolus species. The organic extracts of O. basilicum are potential and promising natural tools for controlling Bipolaris and Cochliobolus species, economically important plant and human fungal pathogens. © 2017 The Society for Applied Microbiology.

  17. Seedling growth in greenhouse conditions of the forest species Dialium guianense (Aubl. Sandwith

    Directory of Open Access Journals (Sweden)

    Georgina Vargas Simon

    2018-01-01

    Full Text Available Dialium guianense is used for its wood and fruit production, and is a tropical tree species native to evergreen forests. Given the threat these forests face, the purpose of this work was to evaluate the initial growth of the plant under greenhouse conditions, for aiming in the development of propagation programs. Seedlings of the species were transplanted to nursery bags under a completely randomized design and grown for 10 months with an initial population of 200 plants. At the end of the experiment, the shoot and root reached lengths of 32.8 and 28.9 cm, respectively. The average number of composite leaves was 12.3 each with seven leaflets. The average biomass was 2.5 g for the shoot, 1.6 g for roots, and 3.7 g for leaves, with a shoot/root around four. The average relative growth rate (RGR was 15 mg g-1 day-. These characteristics indicate that D. guianense is a late successional species.

  18. A broadleaf species enhances an autotoxic conifers growth through belowground chemical interactions.

    Science.gov (United States)

    Xia, Zhi-Chao; Kong, Chui-Hua; Chen, Long-Chi; Wang, Peng; Wang, Si-Long

    2016-09-01

    Plants may affect the performance of neighboring plants either positively or negatively through interspecific and intraspecific interactions. Productivity of mixed-species systems is ultimately the net result of positive and negative interactions among the component species. Despite increasing knowledge of positive interactions occurring in mixed-species tree systems, relatively little is known about the mechanisms underlying such interactions. Based on data from 25-year-old experimental stands in situ and a series of controlled experiments, we test the hypothesis that a broadleaf, non-N fixing species, Michelia macclurei, facilitates the performance of an autotoxic conifer Chinese fir (Cunninghamia lanceolata) through belowground chemical interactions. Chinese fir roots released the allelochemical cyclic dipeptide (6-hydroxy-1,3-dimethyl-8-nonadecyl-[1,4]-diazocane- 2,5-diketone) into the soil environment, resulting in self-growth inhibition, and deterioration of soil microorganisms that improve P availability. However, when grown with M. macclurei the growth of Chinese fir was consistently enhanced. In particular, Chinese fir enhanced root growth and distribution in deep soil layers. When compared with monocultures of Chinese fir, the presence of M. macclurei reduced release and increased degradation of cyclic dipeptide in the soil, resulting in a shift from self-inhibition to chemical facilitation. This association also improved the soil microbial community by increasing arbuscular mycorrhizal fungi, and induced the production of Chinese fir roots. We conclude that interspecific interactions are less negative than intraspecific ones between non-N fixing broadleaf and autotoxic conifer species. The impacts are generated by reducing allelochemical levels, enhancing belowground mutualisms, improving soil properties, and changing root distributions as well as the net effects of all the processes within the soil. In particular, allelochemical context alters the

  19. pCO2 effects on species composition and growth of an estuarine phytoplankton community

    Science.gov (United States)

    Grear, Jason S.; Rynearson, Tatiana A.; Montalbano, Amanda L.; Govenar, Breea; Menden-Deuer, Susanne

    2017-05-01

    The effects of ongoing changes in ocean carbonate chemistry on plankton ecology have important implications for food webs and biogeochemical cycling. However, conflicting results have emerged regarding species-specific responses to pCO2 enrichment and thus community responses have been difficult to predict. To assess community level effects (e.g., production) of altered carbonate chemistry, studies are needed that capitalize on the benefits of controlled experiments but also retain features of intact ecosystems that may exacerbate or ameliorate the effects observed in single-species or single cohort experiments. We performed incubations of natural plankton communities from Narragansett Bay, RI, USA in winter at ambient bay temperatures (5-13 °C), light and nutrient concentrations. Three levels of controlled and constant CO2 concentrations were imposed, simulating past, present and future conditions at mean pCO2 levels of 224, 361, and 724 μatm respectively. Samples for carbonate analysis, chlorophyll a, plankton size-abundance, and plankton species composition were collected daily and phytoplankton growth rates in three different size fractions (20 μm) were measured at the end of the 7-day incubation period. Community composition changed during the incubation period with major increases in relative diatom abundance, which were similar across pCO2 treatments. At the end of the experiment, 24-hr growth responses to pCO2 levels varied as a function of cell size. The smallest size fraction (20 μm size fraction. Cell size distribution shifted toward smaller cells in both the Past and Future treatments but remained unchanged in the Present treatment. Similarity in Past and Future treatments for cell size distribution and growth rate (5-20 μm size fraction) illustrate non-monotonic effects of altered pCO2 on ecological indicators and may be related to opposing physiological effects of high CO2 and low pH both within and among species. Interaction of these effects

  20. Spatial and temporal features of the growth of a bacterial species colonizing the zebrafish gut.

    Science.gov (United States)

    Jemielita, Matthew; Taormina, Michael J; Burns, Adam R; Hampton, Jennifer S; Rolig, Annah S; Guillemin, Karen; Parthasarathy, Raghuveer

    2014-12-16

    The vertebrate intestine is home to microbial ecosystems that play key roles in host development and health. Little is known about the spatial and temporal dynamics of these microbial communities, limiting our understanding of fundamental properties, such as their mechanisms of growth, propagation, and persistence. To address this, we inoculated initially germ-free zebrafish larvae with fluorescently labeled strains of an Aeromonas species, representing an abundant genus in the zebrafish gut. Using light sheet fluorescence microscopy to obtain three-dimensional images spanning the gut, we quantified the entire bacterial load, as founding populations grew from tens to tens of thousands of cells over several hours. The data yield the first ever measurements of the growth kinetics of a microbial species inside a live vertebrate intestine and show dynamics that robustly fit a logistic growth model. Intriguingly, bacteria were nonuniformly distributed throughout the gut, and bacterial aggregates showed considerably higher growth rates than did discrete individuals. The form of aggregate growth indicates intrinsically higher division rates for clustered bacteria, rather than surface-mediated agglomeration onto clusters. Thus, the spatial organization of gut bacteria both relative to the host and to each other impacts overall growth kinetics, suggesting that spatial characterizations will be an important input to predictive models of host-associated microbial community assembly. Our intestines are home to vast numbers of microbes that influence many aspects of health and disease. Though we now know a great deal about the constituents of the gut microbiota, we understand very little about their spatial structure and temporal dynamics in humans or in any animal: how microbial populations establish themselves, grow, fluctuate, and persist. To address this, we made use of a model organism, the zebrafish, and a new optical imaging technique, light sheet fluorescence microscopy

  1. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Science.gov (United States)

    Jiang, Yuan; Zhang, Wentao; Wang, Mingchang; Kang, Muyi; Dong, Manyu

    2014-01-01

    North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1) The two species grew in different rhythms at low and high elevation respectively; (2) Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3) The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4) The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  2. Growth response of four freshwater algal species to dissolved organic nitrogen of different concentration and complexity

    DEFF Research Database (Denmark)

    Fiedler, Dorothea; Graeber, Daniel; Badrian, Maria

    2015-01-01

    1. Dissolved organic nitrogen (DON) compounds dominate the nitrogen pool of many lakes, but their importance as nitrogen sources for freshwater phytoplankton is not fully understood. Previous growth experiments demonstrated the availability of urea and amino acids but often at unnaturally high...... cases matched by nitrate. 4. Urea was also utilised over a longer time period than any other compound, including nitrate. The assumed delay in availability with increasing compound complexity was not supported by this experiment. 5. The studied species differed in their temporal response...... and their compound preferences. Therefore, DON composition can influence biomass and structure of phytoplankton communities. 6. These experiments demonstrate the importance of the main DON compounds for phytoplankton growth when no inorganic nitrogen is available. DON should in future be included in nitrogen budget...

  3. Allelopathic relations of selected cereal and vegetable species during seed germination and seedling growth

    Directory of Open Access Journals (Sweden)

    Bojović Biljana M.

    2015-01-01

    Full Text Available Allelopathy is the direct or indirect harmful effect which one plant produces on another through the production of chemical compounds that escape into the environment. In the presence paper allelopathic relationships were determined in three cereals - wheat (Triticum aestivum L., barley (Hordeum vulgare L., oat (Avena sativa L. and vegetable crops - spinach (Spinacia oleracea L., radish (Raphanus sativus L., pepper (Capsicum annum L.. In addition to the percentage of germination, allelopathic potential was tested measuring root and stem length of tested plant species germinated either alone or in combination with others. The obtained results showed that seed germination and plant growth of cereals and vegetables are depended on the presence of other plants in all tested combinations. In this study has proven largely inhibitory allelopathic effect on germination and plant growth.

  4. Effect of evaporation on the growth kinetics in a model for two species

    International Nuclear Information System (INIS)

    El-Nashar, Hassan F.

    2002-02-01

    A surface growth model for two species is proposed, when deposition, surface diffusion and evaporation are considered, in (1+1)-dimensions. A Monte Carlo simulation is carried out, focusing on the effect of evaporation on the evolution of the amount of roughness. The results show that the interplay between deposition, surface diffusion and evaporation slows down the rate of growth of the surface width. In addition, when the rate of evaporation increases, the surface width grows faster to a higher value, in comparison to the case of low rate of evaporation. This introduces changes in the scaling exponents which show that evaporation should be given equal or as much consideration as deposition and surface relaxation. (author)

  5. The expression of glycerol facilitators from various yeast species improves growth on glycerol of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Mathias; Islam, Zia ul; Knudsen, Peter Boldsen

    2016-01-01

    Glycerol is an abundant by-product during biodiesel production and additionally has several assets compared to sugars when used as a carbon source for growing microorganisms in the context of biotechnological applications. However, most strains of the platform production organism Saccharomyces...... cerevisiae grow poorly in synthetic glycerol medium. It has been hypothesized that the uptake of glycerol could be a major bottleneck for the utilization of glycerol in S. cerevisiae. This species exclusively relies on an active transport system for glycerol uptake. This work demonstrates that the expression...... of predicted glycerol facilitators (Fps1 homologues) from superior glycerol-utilizing yeast species such as Pachysolen tannophilus, Komagataella pastoris, Yarrowia lipolytica and Cyberlindnera jadinii significantly improves the growth performance on glycerol of the previously selected glycerol-consuming S...

  6. The Effect of Fermentation Temperature on the Growth Kinetics of Wine Yeast Species

    OpenAIRE

    ŞENER, Aysun; CANBAŞ, Ahmet; ÜNAL, M. Ümit

    2014-01-01

    The effect of fermentation temperature (18 and 25 °C) on kinetic and yield parameters of ethanol fermentation by Saccharomyces cerevisiae (Zymaflore VL1) and Saccharomyces cerevisiae (Uvaferm CM) was examined using the white Emir grape that is grown in the Nevşehir-Ürgüp region of Turkey. Growth of both yeast species varied according to temperature. Kinetic and yield parameters were both temperature dependent. Sensory evaluation showed that the taste panel was able to discern the wines fermen...

  7. Operculina from the northwestern Pacific (Sesoko Island, Japan) Species Differentiation, Population Dynamics, Growth and Development

    Science.gov (United States)

    Woeger, Julia; Eder, Wolfgang; Kinoshita, Shunichi; Briguglio, Antonino; Hohenegger, Johann

    2017-04-01

    During the last decades larger benthic foraminifera have gained importance as indicator species and are used in a variety of applications, from ecological monitoring, studying the effects of ocean acidification, or reconstructing paleoenvironments. They significantly contribute to the carbonate budget of costal areas and are invaluable tools in biostratigraphy. Even before their advancement as bioindicators, laboratory experiments have been conducted to investigate the effects of various ecological parameters on community composition, biology of single species, or investigating the effects of salinity and temperature on stable isotope composition of the foraminiferal test, to name only a few. The natural laboratory approach (continuous sampling over a period of more than one year) was conducted at the island of Sesoko (Okinawa, Japan). in combination with µ-CT scanning was used to reveal population dynamics of 3 different morphotypes of Operculina. The clarification of reproductive cycles as well as generation and size abundances were used to calculate natural growth models. Best fit was achieved using Bertalanffy and Michaelis-Menten functions. Exponential-, logistic-, generalized logistic-, Gompertz-function yielded weaker fits, when compared by coefficient of determination as well as Akaike Information criterion. The resulting growth curves and inferred growth rates were in turn used to evaluate the quality of a laboratory cultivation experiment carried out simultaneously over a period of 15 months. Culturing parameters such as temperature, light intensities, salinity and pH and light-dark duration were continuously adapted to measurements in the field. The average investigation time in culture was 77days. 13 Individuals lived more than 200 days, 3 reproduced asexually and one sexually. 14% of 186 Individuals were lost, while 22% could not be kept alive for more than one month. Growth curves also represent an instrumental source of information for the various

  8. Seedling emergence, growth and trace elements tolerance and accumulation by Lamiaceae species in a mine soil.

    Science.gov (United States)

    Parra, A; Zornoza, R; Conesa, E; Gómez-López, M D; Faz, A

    2014-10-01

    The potential use of three Laminaceae species (Lavandula dentata, Rosmarinus officinalis and Thymus vulgaris) for the phytostabilisation of a trace elements contaminated (acid) soil has been evaluated. These species were grown in mine tailing soil unamended (TS) and amended with calcium carbonate and pig manure (ATS), and unpolluted substrate for control (CT); plant growth, root characterisation, soil trace elements contents and their accumulation in plants were measured. Results indicated that seed emergence was independent from substrate characteristics, but seedlings died in TS with 40% survival in ATS. The biomass of L. dentata and T. vulgaris and root development in R. officinalis were negatively affected when grown in TS but without differences between ATS and CT. Applicating amendments reduced soil exchangeable and extractable fractions concentrations of trace elements in ATS compared with TS. The establishment of L. dentata and R. officinalis were related to trace elements immobilisation. Trace element concentrations in plants grown in tailing soils were similar to those reported for control, although applicating amendments reduced Zn accumulation in all species, and favoured increased absorption and aerial translocation of As and Pb by L. dentata and T. vulgaris; nonetheless, levels were below toxicity thresholds. Thus, these species fulfill the criteria for phytostabilisation purposes, aided by employing amendments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Modeling the Impact of Spatial Structure on Growth Dynamics of Invasive Plant Species

    Science.gov (United States)

    Murphy, James T.; Johnson, Mark P.; Walshe, Ray

    2013-07-01

    Invasive nonindigenous plant species can have potentially serious detrimental effects on local ecosystems and, as a result, costly control efforts often have to be put in place to protect habitats. An example of an invasive problem on a global scale involves the salt marsh grass species from the genus Spartina. The spread of Spartina anglica in Europe and Asia has drawn much concern due to its ability to convert coastal habitats into cord-grass monocultures and to alter the native food webs. However, the patterns of invasion of Spartina species are amenable to spatially-explicit modeling strategies that take into account both temporal and spatio-temporal processes. In this study, an agent-based model of Spartina growth on a simulated mud flat environment was developed in order to study the effects of spatial pattern and initial seedling placement on the invasion dynamics of the population. The spatial pattern of an invasion plays a key role in the rate of spread of the species and understanding this can lead to significant cost savings when designing efficient control strategies. We present here a model framework that can be used to explicitly represent complex spatial and temporal patterns of invasion in order to be able to predict quantitatively the impact of these factors on invasion dynamics. This would be a useful tool for assessing eradication strategies and choosing optimal control solutions in order to be able to minimize future control costs.

  10. Comparison of biofilm ecology supporting growth of individual Naegleria species in a drinking water distribution system.

    Science.gov (United States)

    Puzon, Geoffrey J; Wylie, Jason T; Walsh, Tom; Braun, Kalan; Morgan, Matthew J

    2017-04-01

    Free-living amoebae (FLA) are common components of microbial communities in drinking water distribution systems (DWDS). FLA are of clinical importance both as pathogens and as reservoirs for bacterial pathogens, so identifying the conditions promoting amoebae colonisation of DWDSs is an important public health concern for water utilities. We used high-throughput amplicon sequencing to compare eukaryotic and bacterial communities associated with DWDS biofilms supporting distinct FLA species (Naegleria fowleri, N. lovaniensis or Vermamoeba sp.) at sites with similar physical/chemical conditions. Eukaryote and bacterial communities were characteristics of different FLA species presence, and biofilms supporting Naegleria growth had higher bacterial richness and higher abundance of Proteobacteria, Bacteroidetes (bacteria), Nematoda and Rotifera (eukaryota). The eukaryotic community in the biofilms had the greatest difference in relation to the presence of N. fowleri, while the bacterial community identified individual bacterial families associated with the presence of different Naegleria species. Our results demonstrate that ecogenomics data provide a powerful tool for studying the microbial and meiobiotal content of biofilms, and, in these samples can effectively discriminate biofilm communities supporting pathogenic N. fowleri. The identification of microbial species associated with N. fowleri could further be used in the management and control of N. fowleri in DWDS. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Phytoremediatory effect and growth of two species of Ocimum in endosulfan polluted soil.

    Science.gov (United States)

    Ramírez-Sandoval, M; Melchor-Partida, G N; Muñiz-Hernández, S; Girón-Pérez, M I; Rojas-García, A E; Medina-Díaz, I M; Robledo-Marenco, M L; Velázquez-Fernández, J B

    2011-08-15

    Endosulfan is a hazardous organochlorine pesticide banned or restricted in several countries. However, it has been found in the environment and in animal samples. To study a potential way to bioremediate soils contaminated with this pesticide, two plant species of the genus Ocimum were studied: Ocimum basilicum L. and Ocimum minimum L., since they are economically feasible and well adapted to the climatic conditions of the Nayarit zone (Mexican pacific coast). Young plants were transplanted into soil experimentally polluted with endosulfan. Growth of both species was not affected by endosulfan, the plants grew, flourished, and produced seeds; 30 days later, endosulfan concentration was lower in the soil with O. basilicum than in the soil without plants. On day 90, no differences in endosulfan concentrations were found between soil with or without O. minimum. At day 1, plants in the polluted soil showed lipoperoxidation, as measured by thiobarbituric acid-reactive species (TBARS). Interestingly, a higher TBARS value was observed at day 3 in transplanted plants as compared to non-transplanted plants. In conclusion, both species can endure endosulfan pollution (as high as 1 g kg(-1)) in soils. O. basilicum seems to be an adequate candidate for bioremediation of soils polluted with endosulfan. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Differences in the growth response of three bryophyte species to nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Salemaa, Maija [Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa (Finland)], E-mail: maija.salemaa@metla.fi; Maekipaeae, Raisa [Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa (Finland)], E-mail: raisa.makipaa@metla.fi; Oksanen, Jari [University of Oulu, Department of Biology, P.O. Box 3000, FI-90014 Oulu (Finland)], E-mail: jarioksa@sun3.oulu.fi

    2008-03-15

    The effect of nitrogen on biomass production, shoot elongation and relative density of the mosses Pleurozium schreberi, Hylocomium splendens and Dicranum polysetum was studied in a chamber experiment. Monocultures were exposed to 10 N levels ranging from 0.02 to 7.35 g N m{sup -2} during a 90-day period. All the growth responses were unimodal, but the species showed differences in the shape parameters of the curves. Hylocomium and Pleurozium achieved optimum biomass production at a lower N level than Dicranum. Pleurozium had the highest biomass production per tissue N concentration. Tolerance to N was the widest in Dicranum, whereas Hylocomium had the narrowest tolerance. Dicranum retained N less efficiently from precipitation than the other two species, which explained its deviating response. All species translocated some N from parent to new shoots. The results emphasize that the individual responses of bryophytes to N should be known when species are used as bioindicators. - Boreal bryophytes display differences in their sensitivity to nitrogen.

  13. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    Science.gov (United States)

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Influence of the residue from an iron mining dam in the growth of two macrophyte species.

    Science.gov (United States)

    Bottino, F; Milan, J A M; Cunha-Santino, M B; Bianchini, I

    2017-11-01

    On November 5th, 2015 the worst environmental disaster in Brazil spilled 60 million m 3 of iron mining residue into Gualaxo do Norte River (Minas Gerais State), an affluent of the highest River Basin of the Brazilian Southeast (Doce River Basin), reaching the Atlantic Ocean. To assess the impact of the iron residue on the aquatic plant metabolism, we performed macrophyte growth experiments under controlled light and temperature conditions using two species (Egeria densa and Chara sp.). The plants' growth data were fitted in a kinetic model to obtain the biomass yields (K) and growth rates (μ). Turbidity and electrical conductivity of the water were measured over time. Both plants showed the highest growth rates in the contaminated condition (0.056 d -1 for E. densa and 0.45 d -1 for Chara sp.) and the biomass increased in the short-term (≈20 days). The control condition (i.e. no impacted water) supported the biomass increasing over time and the development of vegetative buddings with high daily rates (1.75 cm d -1 for E. densa and 0.13 cm d -1 for Chara sp). Turbidity showed a sharp decrease in 48 h and had no effects in the plants growth in the contaminated condition. The contamination affected the plants' yields in the long-term affecting the biomass development. This study provides preliminary information about the ecological consequences of a mining dam rupture aiming to collaborate with monitoring and risk assessments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Effects of air pollution from road transport on growth and physiology of six transplanted bryophyte species

    International Nuclear Information System (INIS)

    Bignal, Keeley L.; Ashmore, Mike R.; Headley, Alistair D.

    2008-01-01

    Motor vehicles emit a cocktail of pollutants; however, little is known about the effects of these pollutants on bryophytes located in roadside habitats. Six bryophyte species were transplanted to either a woodland or a moorland site adjacent to a motorway, and were monitored over seven months from autumn through to spring. All species showed an increase in one or more of the following near the motorway: growth, membrane leakage, chlorophyll concentration, and nitrogen concentration. The strongest effects were observed in the first 50-100 m from the motorway: this was consistent with the nitrogen dioxide pollution profile, which decreased to background levels at a distance of 100-125 m. It is hypothesised that motor vehicle pollution was responsible for the effects observed, and that nitrogen oxides had a key influence. The observed effects may lead to changes in vegetation composition with significant implications for nature conservation and management of roadside sites. - Motor vehicle pollution has significant effects on the growth, membrane leakage, chlorophyll and nitrogen content of bryophytes

  16. Exponential growth combined with exponential decline explains lifetime performance evolution in individual and human species.

    Science.gov (United States)

    Berthelot, Geoffroy; Len, Stéphane; Hellard, Philippe; Tafflet, Muriel; Guillaume, Marion; Vollmer, Jean-Claude; Gager, Bruno; Quinquis, Laurent; Marc, Andy; Toussaint, Jean-François

    2012-08-01

    The physiological parameters characterizing human capacities (the ability to move, reproduce or perform tasks) evolve with ageing: performance is limited at birth, increases to a maximum and then decreases back to zero at the day of death. Physical and intellectual skills follow such a pattern. Here, we investigate the development of sport and chess performances during the lifetime at two different scales: the individual athletes' careers and the world record by age class in 25 Olympic sports events and in grandmaster chess players. For all data sets, a biphasic development of growth and decline is described by a simple model that accounts for 91.7% of the variance at the individual level and 98.5% of the variance at the species one. The age of performance peak is computed at 26.1 years old for the events studied (26.0 years old for track and field, 21.0 years old for swimming and 31.4 years old for chess). The two processes (growth and decline) are exponential and start at age zero. Both were previously demonstrated to happen in other human and non-human biological functions that evolve with age. They occur at the individual and species levels with a similar pattern, suggesting a scale invariance property.

  17. Effects of air pollution from road transport on growth and physiology of six transplanted bryophyte species

    Energy Technology Data Exchange (ETDEWEB)

    Bignal, Keeley L. [Department of Geography and Environmental Science, University of Bradford, Bradford BD7 1DP (United Kingdom)], E-mail: k.bignal@sussex.ac.uk; Ashmore, Mike R. [Department of Geography and Environmental Science, University of Bradford, Bradford BD7 1DP (United Kingdom)], E-mail: ma512@york.ac.uk; Headley, Alistair D. [Department of Geography and Environmental Science, University of Bradford, Bradford BD7 1DP (United Kingdom)], E-mail: alistairheadley@aol.com

    2008-11-15

    Motor vehicles emit a cocktail of pollutants; however, little is known about the effects of these pollutants on bryophytes located in roadside habitats. Six bryophyte species were transplanted to either a woodland or a moorland site adjacent to a motorway, and were monitored over seven months from autumn through to spring. All species showed an increase in one or more of the following near the motorway: growth, membrane leakage, chlorophyll concentration, and nitrogen concentration. The strongest effects were observed in the first 50-100 m from the motorway: this was consistent with the nitrogen dioxide pollution profile, which decreased to background levels at a distance of 100-125 m. It is hypothesised that motor vehicle pollution was responsible for the effects observed, and that nitrogen oxides had a key influence. The observed effects may lead to changes in vegetation composition with significant implications for nature conservation and management of roadside sites. - Motor vehicle pollution has significant effects on the growth, membrane leakage, chlorophyll and nitrogen content of bryophytes.

  18. [Growth rings in roots of seven Sect. Paeonia species and its application on identification of Paeoniae Radix Rubra].

    Science.gov (United States)

    Chu, Shan-Shan; Zha, Liang-Ping; Duan, Hai-Yan; Xu, Tao; Peng, Hua-Sheng

    2017-10-01

    The growth years of medicinal materials are closely related to their quality, and "Herb-chronology" has been used to determine the growth years of perennial dicotyledonous plants in recent years. On the basis of conventional paraffin section and freehand section, the anatomical study on roots of seven Sect. Paeonia species and main roots of cultivated Paeonia lactiflora was conducted in this paper. The results showed that, there existed some differences in microstructure of the seven species such as P. lactiflora, P. obovata, P. veitchii, P. mairei, P. anomala, P. sinjiangensis and P. anomala var. intermedia, and this could be used to distinguish different species. In the roots of seven Sect. Paeonia species, distinct growth rings were formed because that the different diameters or density of xylem vessels in the secondary xylem formed clusters and arranged interrupted rings in tangential direction. There were growth rings in the main roots of P. lactiflora cultivated 1-4 years in Siping, Jilin, which were all consistent with their growth years. Due to the similar growth characteristics between wild Sect. Paeonia species and cultivated P. lactiflora, the growth rings can provide a basis for the age identification and lay the foundation for the quality evaluation of Paeoniae Radix Rubra. Copyright© by the Chinese Pharmaceutical Association.

  19. Estimating root collar diameter growth for multi-stem western woodland tree species on remeasured forest inventory and analysis plots

    Science.gov (United States)

    Michael T. Thompson; Maggie. Toone

    2012-01-01

    Tree diameter growth models are widely used in many forestry applications, often to predict tree size at a future point in time. Also, there are instances where projections of past diameters are needed. An individual tree model has been developed to estimate diameter growth of multi-stem woodland tree species where the diameter is measured at root collar. The model was...

  20. A comparison of stable caesium uptake by six grass species of contrasting growth strategy

    International Nuclear Information System (INIS)

    Willey, N.J.; Martin, M.H.

    1997-01-01

    Six plants in the family Gramineae were used to investigate the relationship between Cs uptake, nutrient regime and plant growth strategy sensu Grime (1979: Plant Growth Strategies and Vegetation Processes, John Wiley). The roots of 66 day old Elymus repens (L.) Gould., Bromus sterilis L., Agrostis stolonifera L., Anthoxanthum odoratum L., Festuca ovina L. and Nardus stricta L. plants grown in acid-washed sand at high and low nutrient levels were exposed to a 96 h pulse of stable Cs at 0.05 mM, 0.15 mM, 0.3 mM, 1.0 mM and 3.0 mM concentrations. Different nutrient regimes induced large differences in dry wt in E. repens, B. sterilis and A. stolonifera plants but only small differences in N. stricta and F. ovina plants. At high nutrient concentrations, A. stolonifera, A. odoratum, F. ovina and N. stricta shoots showed significantly greater increases in internal Cs concentration with rising external Cs concentrations than did E. repens and B. sterilis shoots. The relationship between increases in shoot and external Cs concentrations was statistically indistinguishable between species in plants grown at the low nutrient concentration. These patterns of Cs uptake ensured that with long-term high K concentrations the more competitive plants (E. repens and B. sterilis) accumulated higher concentrations of Cs from low external concentrations than did non-competitive plants or competitive plants grown at low nutrient levels. It is suggested that the relationship between plant growth strategy sensu Grime (1979) and Cs accumulation patterns may help to explain the different concentrations to which species accumulate radiocaesium from the soil. (author)

  1. Generalities in the growth, allocation and leaf quality responses to elevated CO2 in eight woody species

    NARCIS (Netherlands)

    Cornelissen, J. H C; Carnelli, A. L.; Callaghan, Terry V.

    This paper reports general patterns of relative growth rate and related traits in response to elevated atmospheric CO2 in eight woody species ranging widely in life form, leaf habit, taxonomy and ecology. Young plants of these species, all of comparable ontogenetic phases, were grown simultaneously

  2. Growth limitation of three Arctic sea-ice algae species: effects of salinitty, pH and inorganic carbon availability

    DEFF Research Database (Denmark)

    Søgaard, Dorte Haubjerg; Hansen, Per Juel; Rysgaard, Søren

    2011-01-01

    The effect of salinity, pH, and dissolved inorganic carbon (TCO(2)) on growth and survival of three Arctic sea ice algal species, two diatoms (Fragilariopsis nana and Fragilariopsis sp.), and one species of chlorophyte (Chlamydomonas sp.) was assessed in controlled laboratory experiments. Our res...

  3. Fern Stomatal Responses to ABA and CO2Depend on Species and Growth Conditions.

    Science.gov (United States)

    Hõrak, Hanna; Kollist, Hannes; Merilo, Ebe

    2017-06-01

    Changing atmospheric CO 2 levels, climate, and air humidity affect plant gas exchange that is controlled by stomata, small pores on plant leaves and stems formed by guard cells. Evolution has shaped the morphology and regulatory mechanisms governing stomatal movements to correspond to the needs of various land plant groups over the past 400 million years. Stomata close in response to the plant hormone abscisic acid (ABA), elevated CO 2 concentration, and reduced air humidity. Whether the active regulatory mechanisms that control stomatal closure in response to these stimuli are present already in mosses, the oldest plant group with stomata, or were acquired more recently in angiosperms remains controversial. It has been suggested that the stomata of the basal vascular plants, such as ferns and lycophytes, close solely hydropassively. On the other hand, active stomatal closure in response to ABA and CO 2 was found in several moss, lycophyte, and fern species. Here, we show that the stomata of two temperate fern species respond to ABA and CO 2 and that an active mechanism of stomatal regulation in response to reduced air humidity is present in some ferns. Importantly, fern stomatal responses depend on growth conditions. The data indicate that the stomatal behavior of ferns is more complex than anticipated before, and active stomatal regulation is present in some ferns and has possibly been lost in others. Further analysis that takes into account fern species, life history, evolutionary age, and growth conditions is required to gain insight into the evolution of land plant stomatal responses. © 2017 American Society of Plant Biologists. All Rights Reserved.

  4. A new species of Burkholderia isolated from sugarcane roots promotes plant growth.

    Science.gov (United States)

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G A; Yeoh, Yun Kit; Webb, Richard I; Lakshmanan, Prakash; Chan, Cheong Xin; Lim, Phaik-Eem; Ragan, Mark A; Schmidt, Susanne; Hugenholtz, Philip

    2014-03-01

    Sugarcane is a globally important food, biofuel and biomaterials crop. High nitrogen (N) fertilizer rates aimed at increasing yield often result in environmental damage because of excess and inefficient application. Inoculation with diazotrophic bacteria is an attractive option for reducing N fertilizer needs. However, the efficacy of bacterial inoculants is variable, and their effective formulation remains a knowledge frontier. Here, we take a new approach to investigating diazotrophic bacteria associated with roots using culture-independent microbial community profiling of a commercial sugarcane variety (Q208(A) ) in a field setting. We first identified bacteria that were markedly enriched in the rhizosphere to guide isolation and then tested putative diazotrophs for the ability to colonize axenic sugarcane plantlets (Q208(A) ) and promote growth in suboptimal N supply. One isolate readily colonized roots, fixed N2 and stimulated growth of plantlets, and was classified as a new species, Burkholderia australis sp. nov. Draft genome sequencing of the isolate confirmed the presence of nitrogen fixation. We propose that culture-independent identification and isolation of bacteria that are enriched in rhizosphere and roots, followed by systematic testing and confirming their growth-promoting capacity, is a necessary step towards designing effective microbial inoculants. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  5. Dual oxidase 2 generated reactive oxygen species selectively mediate the induction of mucins by epidermal growth factor in enterocytes.

    Science.gov (United States)

    Damiano, Simona; Morano, Annalisa; Ucci, Valentina; Accetta, Roberta; Mondola, Paolo; Paternò, Roberto; Avvedimento, V Enrico; Santillo, Mariarosaria

    2015-03-01

    Dual oxidase 2 enzyme is a member of the reactive oxygen species-generating cell membrane NADPH oxidases involved in mucosal innate immunity. It is not known if the biological activity of dual oxidase 2 is mediated by direct bacterial killing by reactive oxygen species produced by the enzyme or by the same reactive oxygen species acting as second messengers that stimulate novel gene expression. To uncover the role of reactive oxygen species and dual oxidases as signaling molecules, we have dissected the pathway triggered by epidermal growth factor to induce mucins, the principal protective components of gastrointestinal mucus. We show that dual oxidase 2 is essential for selective epidermal growth factor induction of the transmembrane MUC3 and the secreted gel-forming MUC5AC mucins. Reactive oxygen species generated by dual oxidase 2 stabilize tyrosine phosphorylation of epidermal growth factor receptor and induce MUC3 and MUC5AC through persistent activation of extracellular signal-regulated kinases 1/2-protein kinase C. Knocking down dual oxidase 2 by selective RNA targeting (siRNA) reduced epidermal growth factor receptor phosphorylation, and MUC3 and MUC5AC gene expression. Extracellular reactive oxygen species produced by dual oxidase 2, upon stimulation by epidermal growth factor, stabilize epidermal growth factor receptor phosphorylation and activate extracellular signal-regulated kinases 1/2-protein kinase C which induce MUC5AC and MUC3. Extracellular reactive oxygen species produced by dual oxidase 2 that are known to directly kill bacteria, also contribute to the maintenance of the epidermal growth factor-amplification loop, which induces mucins. These data suggest a new function of dual oxidase 2 protein in the luminal protection of the gastrointestinal tract through the induction of mucin expression by growth factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Crosstalk between sugarcane and a plant-growth promoting Burkholderia species.

    Science.gov (United States)

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G A; Yeoh, Yun Kit; Donose, Bogdan C; Webb, Richard I; Parsons, Jeremy; Liao, Webber; Sagulenko, Evgeny; Lakshmanan, Prakash; Hugenholtz, Philip; Schmidt, Susanne; Ragan, Mark A

    2016-11-21

    Bacterial species in the plant-beneficial-environmental clade of Burkholderia represent a substantial component of rhizosphere microbes in many plant species. To better understand the molecular mechanisms of the interaction, we combined functional studies with high-resolution dual transcriptome analysis of sugarcane and root-associated diazotrophic Burkholderia strain Q208. We show that Burkholderia Q208 forms a biofilm at the root surface and suppresses the virulence factors that typically trigger immune response in plants. Up-regulation of bd-type cytochromes in Burkholderia Q208 suggests an increased energy production and creates the microaerobic conditions suitable for BNF. In this environment, a series of metabolic pathways are activated in Burkholderia Q208 implicated in oxalotrophy, microaerobic respiration, and formation of PHB granules, enabling energy production under microaerobic conditions. In the plant, genes involved in hypoxia survival are up-regulated and through increased ethylene production, larger aerenchyma is produced in roots which in turn facilitates diffusion of oxygen within the cortex. The detected changes in gene expression, physiology and morphology in the partnership are evidence of a sophisticated interplay between sugarcane and a plant-growth promoting Burkholderia species that advance our understanding of the mutually beneficial processes occurring in the rhizosphere.

  7. Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.).

    Science.gov (United States)

    Yang, Ruyi; Yu, Guodong; Tang, Jianjun; Chen, Xin

    2008-01-01

    It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species (Solidago canadensis L.) in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels (control, 300, and 600 mg/kg soil) were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae, Glomus versiform, Glomus diaphanum, Glomus geosporum, and Glomus etunicatum). The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants. The results showed that S. canadensis was highly dependent on mycorrhizae. The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization (root length colonized, RLC%) but did not affect spore numbers, N (including total N and 15N) and P uptake. The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments. The Pb was mostly sequestered in belowground of plant (root and rhizome). The results suggest that the high efficiency of mycorrhizae on nutrient uptake might give S. canadensis a great advantage over native species in Pb polluted soils.

  8. Growth by basal branching in two species of Huicungo palms, Astrocaryum carnosum and A. huicungo

    Directory of Open Access Journals (Sweden)

    Miguel Machahua

    2015-04-01

    Full Text Available The basal branching process of Astrocaryum carnosum and A. huicungo is described and its rate and structural expression at the population level is analyzed. Two populations of palms were used in this study, A. carnosum from the Alto Huallaga valley and A. huicungo from the Alto Mayo valley. Branching systems underground were exposed and drawn. For both species, it was established 25 quadrants of 20x20m, in which were counted (i the number of solitary and caespitose individuals, and (ii the numbers of axes composing the caespitose individuals. The axes of solitary and caespitose individuals were distributed by growth stages (seedling/juvenile-1/juvenile-2/adult. Seedling and juvenile-1 are not caespitose, basal branching starts in juvenile-2. A. huicungo presents a higher density of axes produced by basal branching than A. carnosum. This branching process in both species by formations of clones from short rhizomes allows an optimized exploitation of space and ensures the continuity of the population over time. However, its role in the spatial propagation of the species is very limited by the shortness of the rhizomes.

  9. Silica distribution in various bamboos species and its effects on plant growth

    Science.gov (United States)

    Collin, B.; Meunier, J.; Keller, C.; Doelsch, E.; Panfili, F.

    2010-12-01

    Bamboos are distributed throughout the world’s temperate, tropical and subtropical regions. They are widely used in industry, as fresh edible shoots, paper maker, building and even in medicine. Bamboos also play multiple ecologic functions such as soil and water conservation and erosion control. Bamboos have generally high silicon (Si) content. Silicon is known to have beneficial effects on plants and alleviate various stresses. The aim of this study is to quantify the Si uptake and distribution in various bamboos species and to investigate the effects of Si on the plant growth. Two complementary studies were carried out, one under natural conditions and one under controlled conditions. First of all, we performed an inventory of Si tissue content in 16 bamboos species growing in a non-polluted tropical soil at the Reunion Island (France, Indian ocean). We determined Si content in leaf and in stem tissues sampled at several heights for each plant. One of these species Gigantocloa sp « Malay Dwarf » was grown for 3 months in nutrient solution at five Si concentrations (0, 0.25, 0.75, 1.15, 1.5 mM Si). Silica deposition was examined in leaves using a cryo-SEM equipped with EDS. The Si concentration varies significantly between species, depending on rhizome morphology. Bamboos having leptomorph rhizomes show significantly higher leaf and stem Si content than that of species having pachymorph rhizomes. The distribution of Si in the plant has the same trends for all species. Leaves are the most concentrated organs (10.9 %), and within the stem Si concentration significantly increases from the bottom (0.32%) to the top of the plant (2.1%). Plant Si content increases with the Si supply. Leaves of Gigantocloa sp « Malay Dwarf » accumulate 15.2 % of Si under natural conditions and up to 24 % when exposed to the highest Si treatment. Unlike previous studies, our experiment shows that the concentration of Si had no significant effect on nutrient uptake and biomass

  10. Exponential growth for self-reproduction in a catalytic reaction network: relevance of a minority molecular species and crowdedness

    Science.gov (United States)

    Kamimura, Atsushi; Kaneko, Kunihiko

    2018-03-01

    Explanation of exponential growth in self-reproduction is an important step toward elucidation of the origins of life because optimization of the growth potential across rounds of selection is necessary for Darwinian evolution. To produce another copy with approximately the same composition, the exponential growth rates for all components have to be equal. How such balanced growth is achieved, however, is not a trivial question, because this kind of growth requires orchestrated replication of the components in stochastic and nonlinear catalytic reactions. By considering a mutually catalyzing reaction in two- and three-dimensional lattices, as represented by a cellular automaton model, we show that self-reproduction with exponential growth is possible only when the replication and degradation of one molecular species is much slower than those of the others, i.e., when there is a minority molecule. Here, the synergetic effect of molecular discreteness and crowding is necessary to produce the exponential growth. Otherwise, the growth curves show superexponential growth because of nonlinearity of the catalytic reactions or subexponential growth due to replication inhibition by overcrowding of molecules. Our study emphasizes that the minority molecular species in a catalytic reaction network is necessary for exponential growth at the primitive stage of life.

  11. pCO2 Effects on Species Composition and Growth of an Estuarine Phytoplankton Community

    Science.gov (United States)

    Grear, J. S.; Rynearson, T. A.; Montalbano, A. L.; Govenar, B. W.; Menden-Deuer, S.

    2016-02-01

    Ocean and coastal waters are experiencing changes in carbonate chemistry, including pH, in response to increasing atmospheric CO2 concentration and the microbial degradation of organic matter associated with nutrient enrichment. The effects of this change on plankton communities have important implications for food webs and biogeochemical cycling. However, conflicting results have emerged regarding responses of phytoplankton species and communities to experimental CO2 enrichment. We performed winter "ecostat" incubations of natural plankton communities from lower Narragansett Bay at ambient bay temperatures (5-13 C), light, and nutrients under three levels of CO2 enrichment simulating past, present and future conditions (mean pCO2 levels were 224, 361, and 724 uatm). Major increases in relative diatom abundance occurred during the experiment but were similar across pCO2 treatments. At the end of the experiment, 24-hr growth responses to pCO2 varied as a function of cell size. The smallest size fraction ( 20 µm size fraction. Cell size distribution shifted toward smaller cells in both the Past and Future treatments but remained unchanged in the Present treatment. These non-monotonic effects of increasing pCO2 may be related to opposing physiological effects of high CO2 vs low pH both within and among species. Interaction of these effects with other factors (e.g., nutrients, light, temperature, grazing, initial species composition) may explain variability among published studies. The absence of clear treatment-specific effects at the community level suggest that extrapolation of species-specific responses would produce misleading predictions of ocean acidification impacts on plankton production.

  12. Flowering phenology, growth forms, and pollination syndromes in tropical dry forest species: Influence of phylogeny and abiotic factors.

    Science.gov (United States)

    Cortés-Flores, Jorge; Hernández-Esquivel, Karen Beatriz; González-Rodríguez, Antonio; Ibarra-Manríquez, Guillermo

    2017-01-01

    Analyses of the influence of temporal variation in abiotic factors on flowering phenology of tropical dry forest species have not considered the possible response of species with different growth forms and pollination syndromes, while controlling for phylogenetic relationships among species. Here, we investigated the relationship between flowering phenology, abiotic factors, and plant functional attributes, while controlling for phylogenetic relationship among species, in a dry forest community in Mexico. We characterized flowering phenology (time and duration) and pollination syndromes of 55 tree species, 49 herbs, 24 shrubs, 15 lianas, and 11 vines. We tested the influence of pollination syndrome, growth form, and abiotic factors on flowering phenology using phylogenetic generalized least squares. We found a relationship between flowering duration and time. Growth form was related to flowering time, and the pollination syndrome had a more significant relationship with flowering duration. Flowering time variation in the community was explained mainly by abiotic variables, without an important phylogenetic effect. Flowering time in lianas and trees was negatively and positively correlated with daylength, respectively. Functional attributes, environmental cues, and phylogeny interact with each other to shape the diversity of flowering patterns. Phenological differentiation among species groups revealed multiples strategies associated with growth form and pollination syndromes that can be important for understanding species coexistence in this highly diverse plant community. © 2017 Botanical Society of America.

  13. Pre-germination temperature and the survivorship and onward growth of Mediterranean fire-following plant species

    Science.gov (United States)

    Hanley, Mick E.; Fenner, Michael

    1998-04-01

    The role of heat shock in the induction of seed germination for numerous Mediterranean fire-following plant species is well documented. However, the influence of pre-germination heating of seeds upon seedling survivorship and onward growth has not been studied. The aim of the experiments described here was to investigate how a range of heat treatments affects seedling survivorship and onward growth for six common fire-following Mediterranean plant species ( Anthyllis vulneraria, Cistus creticus, C. salvifolius, Hippocrepis unisiliquosa, Pinus brutia and P. halepensis). In the first experiment, seeds of five species were heated to temperatures ranging between 80°C and 120°C (at 10°C intervals) for 10 min and subsequent seedling growth monitored over 8 weeks. Survivorship for two pine species ( Pinus halepensis and Pinus brutia) was reduced after seeds were heated above 90°C. Onward growth for Pinus halepensis and the legume, Anthyllis vulneraria, was negatively affected by increasing pre-germination temperature. Survivorship and growth for both Cistus species was unaffected by heating seeds up to 110°C. The second experiment examined more closely seedling performance of Hippocrepis unisiliquosa seedlings when seeds were heated to temperatures ranging between 50°C and 90°C (at 10°C intervals) for 5, 10, 15 and 20 mins. Increasing pre-germination temperature and the length of time seeds were exposed to heating significantly reduced seedling growth rates in this species. The effect of fire on seedling emergence, growth and survivorship in the field is discussed with reference to the adaptation of the six species to post-fire regeneration and the patterns of seedling regeneration observed in the field.

  14. Numerical simulation of a thermodynamically consistent four-species tumor growth model.

    Science.gov (United States)

    Hawkins-Daarud, Andrea; van der Zee, Kristoffer G; Oden, J Tinsley

    2012-01-01

    In this paper, we develop a thermodynamically consistent four-species model of tumor growth on the basis of the continuum theory of mixtures. Unique to this model is the incorporation of nutrient within the mixture as opposed to being modeled with an auxiliary reaction-diffusion equation. The formulation involves systems of highly nonlinear partial differential equations of surface effects through diffuse-interface models. A mixed finite element spatial discretization is developed and implemented to provide numerical results demonstrating the range of solutions this model can produce. A time-stepping algorithm is then presented for this system, which is shown to be first order accurate and energy gradient stable. The results of an array of numerical experiments are presented, which demonstrate a wide range of solutions produced by various choices of model parameters.

  15. Photosynthate consumption and carbon turnover in the rhizosphere depending on plant species and growth conditions

    International Nuclear Information System (INIS)

    Sauerbeck, D.R.; Helal, H.M.; Nonnen, S.; Allard, J.-l.

    1982-01-01

    The root tissue which can be isolated from soils represents only part of the total plant carbon incorporation. Between 20 and 40% of the photosynthetic production of plants is expended for root growth and root metabolism. This indicates a striking turnover of energy in the rhizosphere, because relatively litle root-derived organic matter remains there until harvest time. Plant species and variety, soil conditions and temperature were shown to be the most decisive factors governing the assimilate consumption of plant root systems. A special technique is described which enables to study how this extensive turnover affects the surrounding soil depending on its proximity to the roots. Plant-derived carbon can be detected up to 20mm away from the roots. A priming effect has been found on the decomposition of soil organic matter. This explains why, in spite of the rhizo-deposition mentioned, no net-accumulation of carbon in the rhizosphere has been found. (Author) [pt

  16. Growth response of drought-stressed Pinus sylvestris seedlings to single- and multi-species inoculation with ectomycorrhizal fungi.

    Directory of Open Access Journals (Sweden)

    Tabea Kipfer

    Full Text Available Many trees species form symbiotic associations with ectomycorrhizal (ECM fungi, which improve nutrient and water acquisition of their host. Until now it is unclear whether the species richness of ECM fungi is beneficial for tree seedling performance, be it during moist conditions or drought. We performed a pot experiment using Pinus sylvestris seedlings inoculated with four selected ECM fungi (Cenococcum geophilum, Paxillus involutus, Rhizopogon roseolus and Suillus granulatus to investigate (i whether these four ECM fungi, in monoculture or in species mixtures, affect growth of P. sylvestris seedlings, and (ii whether this effect can be attributed to species number per se or to species identity. Two different watering regimes (moist vs. dry were applied to examine the context-dependency of the results. Additionally, we assessed the activity of eight extracellular enzymes in the root tips. Shoot growth was enhanced in the presence of S. granulatus, but not by any other ECM fungal species. The positive effect of S. granulatus on shoot growth was more pronounced under moist (threefold increase than under dry conditions (twofold increase, indicating that the investigated ECM fungi did not provide additional support during drought stress. The activity of secreted extracellular enzymes was higher in S. granulatus than in any other species. In conclusion, our findings suggest that ECM fungal species composition may affect seedling performance in terms of aboveground biomass.

  17. Variation among Desulfovibrio species in electron transfer systems used for syntrophic growth.

    Science.gov (United States)

    Meyer, Birte; Kuehl, Jennifer; Deutschbauer, Adam M; Price, Morgan N; Arkin, Adam P; Stahl, David A

    2013-03-01

    Mineralization of organic matter in anoxic environments relies on the cooperative activities of hydrogen producers and consumers linked by interspecies electron transfer in syntrophic consortia that may include sulfate-reducing species (e.g., Desulfovibrio). Physiological differences and various gene repertoires implicated in syntrophic metabolism among Desulfovibrio species suggest considerable variation in the biochemical basis of syntrophy. In this study, comparative transcriptional and mutant analyses of Desulfovibrio alaskensis strain G20 and Desulfovibrio vulgaris strain Hildenborough growing syntrophically with Methanococcus maripaludis on lactate were used to develop new and revised models for their alternative electron transfer and energy conservation systems. Lactate oxidation by strain G20 generates a reduced thiol-disulfide redox pair(s) and ferredoxin that are energetically coupled to H(+)/CO(2) reduction by periplasmic formate dehydrogenase and hydrogenase via a flavin-based reverse electron bifurcation process (electron confurcation) and a menaquinone (MQ) redox loop-mediated reverse electron flow involving the membrane-bound Qmo and Qrc complexes. In contrast, strain Hildenborough uses a larger number of cytoplasmic and periplasmic proteins linked in three intertwining pathways to couple H(+) reduction to lactate oxidation. The faster growth of strain G20 in coculture is associated with a kinetic advantage conferred by the Qmo-MQ-Qrc loop as an electron transfer system that permits higher lactate oxidation rates under elevated hydrogen levels (thereby enhancing methanogenic growth) and use of formate as the main electron-exchange mediator (>70% electron flux), as opposed to the primarily hydrogen-based exchange by strain Hildenborough. This study further demonstrates the absence of a conserved gene core in Desulfovibrio that would determine the ability for a syntrophic lifestyle.

  18. Growth responses of low-alpine dwarf-shrub heath species to nitrogen deposition and management

    International Nuclear Information System (INIS)

    Britton, Andrea J.; Fisher, Julia M.

    2008-01-01

    Nitrogen deposition is a continuing problem in European alpine regions. We hypothesised that, despite climatic limitations, low-alpine Calluna heathland would respond to nitrogen addition with increased shoot growth and flowering and that fire and grazing would modify responses. In a five-year study, 0-50 kg N ha -1 y -1 were added, combined with burning (+/-) and clipping (+/-). Calluna vulgaris responded with increased shoot extension, but effects on flowering were variable. Burning enhanced the positive effect of nitrogen addition and negative effects of clipping. Sub-dominant shrubs generally did not respond to nitrogen. C. vulgaris shoot extension was stimulated by nitrogen addition of 10 kg N ha -1 y -1 (above background) supporting suggestions that alpine heathlands are sensitive to low levels of nitrogen deposition. Increased C. vulgaris growth could negatively impact on important lichen components of this vegetation through increased shading and competition. Climatic factors constrain productivity in this community, but do not prevent rapid responses to nitrogen deposition by some species. - Low levels of N deposition increase productivity in alpine dwarf-shrub heath despite strong climatic constraints

  19. The effect of three species of mites upon fungal growth on wheat.

    Science.gov (United States)

    Armitage, D M; George, C L

    1986-06-01

    Every week, for 20 weeks, the growth of naturally occurring grain storage fungi on wheat infested with the three commonest British grain storage mites, Acarus siro, Glycyphagus destructor and Tyrophagus longior, was compared with that on uninfested wheat. The number of colonies of the Aspergillus glaucus group per gram were always less on grain infested with mites than on uninfested grain. Penicillium spp. were also less numerous on grain which was infested with A. siro but did not appear to be affected by the other mites. In contrast, two fungi which are pathogenic to mites, Aspergillus restrictus and Wallemia sebi, were more abundant in the presence of certain mites. The former was associated with G. destructor, the latter with G. destructor and A. siro. The three species of mites either feed on the A. glaucus group and Penicillium spp., or inhibit them by an unknown secretion. Pathogenic fungi are probably avoided. Mites are therefore an important variable in studies on fungal growth during grain drying and storage.

  20. In vivo immunotherapy of lung cancer using cross-species reactive vascular endothelial growth factor nanobodies

    Directory of Open Access Journals (Sweden)

    vFatemeh Kazemi-Lomedasht v

    2017-05-01

    Full Text Available Objective(s: Lung cancer is the main leading cause of cancer death worldwide. Angiogenesis is the main step in proliferation and spreading of tumor cells. Targeting vascular endothelial growth factor (VEGF is an effective approach for inhibition of cancer angiogenesis. Nanobodies (NBs are a novel class of antibodies derived from the camel. Unique characteristics of Nbs like their small size and good penetration to tumor tissues makes them promising tools in drug development.  Development of NBs targeting both human and mouse VEGF is required for understanding their in vivo functions.  Therefore, development of cross-species reactive anti-VEGF Nbs for immunotherapy of lung cancer was the main aim of the current study. Materials and Methods: Here we developed NBs from Camelus dromedarius library with high specificity and binding affinity to both human and mouse VEGF. In vitro and In vivo function of developed NB was evaluated on human endothelial cells and lung epithelial tumor cells (TC-1. Results: A nanobody showed the highest affinity to human and mouse VEGF and potently inhibited VEGF in the ELISA experiment. Anti-VEGF NBs significantly inhibited in vitro human endothelial cell migration through blockade of VEGF (P=0.045. Anti-VEGF NBs also significantly inhibited in vivo TC-1 growth in a dose-dependent manner (P=0.001 and resulted in higher survival rate in the nanobody treated group Conclusion: These findings demonstrate the potential of anti-VEGF NBsin tumor growth inhibition and are promising as novel cancer therapeutic candidate.

  1. The Effect of Salinity on Seed Germination and Seedling Growth of Four Medicinal Plant Species

    Directory of Open Access Journals (Sweden)

    H Javadi

    2014-07-01

    Full Text Available To study the effect of salinity stress on seed germination and seedling growth of four medicinal plants, Nigella sativa L., Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus L. an experiment was conducted in the botany laboratory of Islamic Azad University, Birjand branch. A completely randomized design (CRD with 3 replications was used as separately for each species. Treatments were consisted of six salinity (NaCl concentrations (0, 4, 8, 12, 16 and 20 dS m-1. The measured traits were root, shoot and seedling length, dry and fresh weight of seedling, germination rate and percent, seed vigor index, seedling water content and root/ shoot ratio. Salinity stress reduced significantly shoot, root and seedling length of the species. Increasing of salinity stress declined dry and fresh weight of Trigonella foenum and Nigella sativa L. and dry weight of Cannabis sativa L.. Seedling water content and root/ shoot ratio of Nigella sativa L. increased in salinity treatments. Increasing of salinity stress declined germination rate and percent in Nigella sativa L., but in other species (Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus only germination rate decreased. Trigonella foenum graecum germinated completely (%100 in all salinity treatments. Increasing of salinity until 16 dS m-1 reduced seed germination of Nigella sativa. Seed germination of Nigella sativa did not occurred in the highest salinity stress (20 dS m-1. Totally the results showed that in the germination stage, Trigonella foenum graecum and Cannabis sativa were relatively tolerate to salinity stress but Nigella sativa L. was the most sensitive one

  2. Biocontrol and Plant Growth Promotion Characterization of Bacillus Species Isolated from Calendula officinalis Rhizosphere.

    Science.gov (United States)

    Ait Kaki, Asma; Kacem Chaouche, Noreddine; Dehimat, Laid; Milet, Asma; Youcef-Ali, Mounia; Ongena, Marc; Thonart, Philippe

    2013-12-01

    The phenotypic and genotypic diversity of the plant growth promoting Bacillus genus have been widely investigated in the rhizosphere of various agricultural crops. However, to our knowledge this is the first report on the Bacillus species isolated from the rhizosphere of Calendula officinalis. 15 % of the isolated bacteria were screened for their important antifungal activity against Fusarium oxysporum, Botrytis cinerea, Aspergillus niger, Cladosporium cucumerinium and Alternaria alternata. The bacteria identification based on 16S r-RNA and gyrase-A genes analysis, revealed strains closely related to Bacillus amyloliquefaciens, B. velezensis, B. subtilis sub sp spizezenii and Paenibacillus polymyxa species. The electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC MS) analysis showed that most of the Bacillus isolates produced the three lipopeptides families. However, the P. polymyxa (18SRTS) didn't produce any type of lipopeptides. All the tested Bacillus isolates produced cellulase but the protease activity was observed only in the B. amyloliquefaciens species (9SRTS). The Salkowsky colorimetric test showed that the screened bacteria synthesized 6-52 μg/ml of indole 3 acetic acid. These bacteria produced siderophores with more than 10 mm wide orange zones on chromazurol S. The greenhouse experiment using a naturally infested soil with Sclerotonia sclerotiorum showed that the B. amyloliquefaciens (9SRTS) had no significant (P > 0.05) effect on the pre-germination of the chickpea seeds. However, it increased the size of the chickpea plants and reduced the stem rot disease (P Bacillus strains isolated in this work may be further used as bioinoculants to improve the production of C. officinalis and other crop systems.

  3. A patchy growth via successive and simultaneous cambia: key to success of the most widespread mangrove species Avicennia marina?

    Science.gov (United States)

    Schmitz, Nele; Robert, Elisabeth M R; Verheyden, Anouk; Kairo, James Gitundu; Beeckman, Hans; Koedam, Nico

    2008-01-01

    Secondary growth via successive cambia has been intriguing researchers for decades. Insight into the mechanism of growth layer formation is, however, limited to the cellular level. The present study aims to clarify secondary growth via successive cambia in the mangrove species Avicennia marina on a macroscopic level, addressing the formation of the growth layer network as a whole. In addition, previously suggested effects of salinity on growth layer formation were reconsidered. A 1-year cambial marking experiment was performed on 80 trees from eight sites in two mangrove forests in Kenya. Environmental (soil water salinity and nutrients, soil texture, inundation frequency) and tree characteristics (diameter, height, leaf area index) were recorded for each site. Both groups of variables were analysed in relation to annual number of growth layers, annual radial increment and average growth layer width of stem discs. Between trees of the same site, the number of growth layers formed during the 1-year study period varied from only part of a growth layer up to four growth layers, and was highly correlated to the corresponding radial increment (0-5 mm year(-1)), even along the different sides of asymmetric stem discs. The radial increment was unrelated to salinity, but the growth layer width decreased with increasing salinity and decreasing tree height. A patchy growth mechanism was proposed, with an optimal growth at distinct moments in time at different positions around the stem circumference. This strategy creates the opportunity to form several growth layers simultaneously, as observed in 14 % of the studied trees, which may optimize tree growth under favourable conditions. Strong evidence was provided for a mainly endogenous trigger controlling cambium differentiation, with an additional influence of current environmental conditions in a trade-off between hydraulic efficiency and mechanical stability.

  4. Effects of TiO2 nanoparticles on the growth and metabolism of three species of freshwater algae

    International Nuclear Information System (INIS)

    Cardinale, Bradley J.; Bier, Raven; Kwan, Courtney

    2012-01-01

    We examined how TiO 2 nanoparticles (nTiO 2 ) impact the growth and metabolism of three species of freshwater green algae (Scenedesmus quadricauda, Chlamydomonas moewusii, and Chlorella vulgaris) that are widespread throughout North America. We exposed laboratory cultures to five initial concentrations of nTiO 2 (0, 50, 100, 200, and 300 ppm) and measured impacts on species population growth rates, as well as on metabolic rates of gross primary production (GPP) and respiration (R). Population growth rates were consistently reduced by nTiO 2 , with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO 2 reduced both GPP and R, but effects on GPP were stronger. As a consequence, carbon was respired more quickly than it was fixed, leading to reduced growth. In contrast, nTiO 2 stimulated both GPP and R in Chorella. But because R was stimulated to a greater extent than GPP, carbon loss again exceeded fixation, leading to reduced growth. For Scenedesmus, nTiO 2 had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO 2 may generally suppress the growth of pelagic algae, but these impacts are manifest through contrasting effects on species-specific metabolic functions. Because growth and metabolism of algae are fundamental to the functioning of ecosystems and the structure of aquatic food-webs, our study suggests nTiO 2 has potential to alter important community and ecosystem properties of freshwater habitats.

  5. Experimental mixture design as a tool to optimize the growth of various Ganoderma species cultivated on media with different sugars

    Directory of Open Access Journals (Sweden)

    Yit Kheng Goh

    2016-01-01

    Full Text Available The influence of different medium components (glucose, sucrose, and fructose on the growth of different Ganoderma isolates and species was investigated using mixture design. Ten sugar combinations based on three simple sugars were generated with two different concentrations, namely 3.3% and 16.7%, which represented low and high sugar levels, respectively. The media were adjusted to either pH 5 or 8. Ganoderma isolates (two G. boninense from oil palm, one Ganoderma species from coconut palm, G. lingzhi, and G. australe from tower tree grew faster at pH 8. Ganoderma lingzhi proliferated at the slowest rate compared to all other tested Ganoderma species in all the media studied. However, G. boninense isolates grew the fastest. Different Ganoderma species were found to have different sugar preferences. This study illustrated that the mixture design can be used to determine the optimal combinations of sugar or other nutrient/chemical components of media for fungal growth.

  6. Characterization of Alternaria and Penicillium species from similar substrata based on growth at different temperature, pH and water activity

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Frisvad, Jens Christian

    2002-01-01

    Fifty-eight Alternaria isolates representing 10 species or species-groups and 66 Penicillium isolates representing 18 species were examined for their growth response to the combined effects of water activity, temperature and pH in an extended Central Composite Design. Growth responses were recorded...

  7. Experimental mixture design as a tool to optimize the growth of various Ganoderma species cultivated on media with different sugars

    OpenAIRE

    Yit Kheng Goh; Nurul Fadhilah Marzuki; Suet Yee Tan; Swee Sian Tan; Hun Jiat Tung; You Keng Goh; Kah Joo Goh

    2016-01-01

    The influence of different medium components (glucose, sucrose, and fructose) on the growth of different Ganoderma isolates and species was investigated using mixture design. Ten sugar combinations based on three simple sugars were generated with two different concentrations, namely 3.3% and 16.7%, which represented low and high sugar levels, respectively. The media were adjusted to either pH 5 or 8. Ganoderma isolates (two G. boninense from oil palm, one Ganoderma species from coconut palm, ...

  8. Insect herbivores increase mortality and reduce tree seedling growth of some species in temperate forest canopy gaps

    Science.gov (United States)

    Burkepile, Deron E.; Parker, John D.

    2017-01-01

    Insect herbivores help maintain forest diversity through selective predation on seedlings of vulnerable tree species. Although the role of natural enemies has been well-studied in tropical systems, relatively few studies have experimentally manipulated insect abundance in temperate forests and tracked impacts over multiple years. We conducted a three-year experiment (2012–2014) deterring insect herbivores from seedlings in new treefall gaps in deciduous hardwood forests in Maryland. During this study, we tracked recruitment of all tree seedlings, as well as survivorship and growth of 889 individual seedlings from five tree species: Acer rubrum, Fagus grandifolia, Fraxinus spp., Liriodendron tulipifera, and Liquidambar styraciflua. Insect herbivores had little effect on recruitment of any tree species, although there was a weak indication that recruitment of A. rubrum was higher in the presence of herbivores. Insect herbivores reduced survivorship of L. tulipifera, but had no significant effects on A. rubrum, Fraxinus spp., F. grandifolia, or L. styraciflua. Additionally, insects reduced growth rates of early pioneer species A. rubrum, L. tulipifera, and L. styraciflua, but had little effect on more shade-tolerant species F. grandifolia and Fraxinus spp. Overall, by negatively impacting growth and survivorship of early pioneer species, forest insects may play an important but relatively cryptic role in forest gap dynamics, with potentially interesting impacts on the overall maintenance of diversity. PMID:28344904

  9. Insect herbivores increase mortality and reduce tree seedling growth of some species in temperate forest canopy gaps

    Directory of Open Access Journals (Sweden)

    Nathan P. Lemoine

    2017-03-01

    Full Text Available Insect herbivores help maintain forest diversity through selective predation on seedlings of vulnerable tree species. Although the role of natural enemies has been well-studied in tropical systems, relatively few studies have experimentally manipulated insect abundance in temperate forests and tracked impacts over multiple years. We conducted a three-year experiment (2012–2014 deterring insect herbivores from seedlings in new treefall gaps in deciduous hardwood forests in Maryland. During this study, we tracked recruitment of all tree seedlings, as well as survivorship and growth of 889 individual seedlings from five tree species: Acer rubrum, Fagus grandifolia, Fraxinus spp., Liriodendron tulipifera, and Liquidambar styraciflua. Insect herbivores had little effect on recruitment of any tree species, although there was a weak indication that recruitment of A. rubrum was higher in the presence of herbivores. Insect herbivores reduced survivorship of L. tulipifera, but had no significant effects on A. rubrum, Fraxinus spp., F. grandifolia, or L. styraciflua. Additionally, insects reduced growth rates of early pioneer species A. rubrum, L. tulipifera, and L. styraciflua, but had little effect on more shade-tolerant species F. grandifolia and Fraxinus spp. Overall, by negatively impacting growth and survivorship of early pioneer species, forest insects may play an important but relatively cryptic role in forest gap dynamics, with potentially interesting impacts on the overall maintenance of diversity.

  10. Effects of calcium on seed germination, seedling growth and photosynthesis of six forest tree species under simulated acid rain.

    Science.gov (United States)

    Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei

    2011-04-01

    We selected six tree species, Pinus massoniana Lamb., Cryptomeria fortunei Hooibr. ex Otto et Dietr., Cunninghamia lanceolata (Lamb.) Hook., Liquidambar formosana Hance, Pinus armandii Franch. and Castanopsis chinensis Hance, which are widely distributed as dominant species in the forest of southern China where acid deposition is becoming more and more serious in recent years. We investigated the effects and potential interactions between simulated acid rain (SiAR) and three calcium (Ca) levels on seed germination, radicle length, seedling growth, chlorophyll content, photosynthesis and Ca content in leaves of these six species. We found that the six species showed different responses to SiAR and different Ca levels. Pinus armandii and C. chinensis were very tolerant to SiAR, whereas the others were more sensitive. The results of significant SiAR × Ca interactions on different physiological parameters of the six species demonstrate that additional Ca had a dramatic rescue effect on the seed germination and seedling growth for the sensitive species under SiAR. Altogether, we conclude that the negative effects of SiAR on seed germination, seedling growth and photosynthesis of the four sensitive species could be ameliorated by Ca addition. In contrast, the physiological processes of the two tolerant species were much less affected by both SiAR and Ca treatments. This conclusion implies that the degree of forest decline caused by long-term acid deposition may be attributed not only to the sensitivity of tree species to acid deposition, but also to the Ca level in the soil.

  11. Growth Responses of Three Dominant Wetland Plant Species to Various Flooding and Nutrient Levels

    Science.gov (United States)

    Barrett, S.; Shaffer, G. P.

    2017-12-01

    Coastal Louisiana is experiencing a greater rate of wetland loss than any other wetland system in the United States. This is primarily due to anthropogenic stressors such as flood control levees, backfilling and development of wetlands, and other hydrologic modifications. Methods employed to mitigate wetland loss include the construction of river diversions and assimilation wetlands, which can provide consistent sources of freshwater influx and nutrients to impounded swamps and marshes. It is well known that prolonged flooding causes strain on wetland plant communities and facilitates or exacerbates wetland degradation. However, because river diversions and assimilation wetlands bring high nutrient loads along with freshwater, there is debate over whether prolonged flooding or high influx of nutrients is the primary cause of stress in river diversion and assimilation wetland discharge areas. This mesocosm experiment addresses this question by isolating the effects of flooding and nutrients on the biomass of baldcypress (Taxodium distichum), maidencane (Panicum hemitomon), and cordgrass (Spartina patens) over the course of a growing season. The results of this study provide clarity as to whether flooding stress, high nutrient loads, or both cause a reduction in wetland plant productivity. By evaluating the growth responses of T. distichum, P. hemitomon, and S. patens at varying nutrient regimes, we gain insight on how these more dominant species will react to high nutrient discharges from large river diversions, such as those proposed in Louisiana's 2017 Master Plan.

  12. Chronic restraint stress inhibits hair growth via substance P mediated by reactive oxygen species in mice.

    Science.gov (United States)

    Liu, Nan; Wang, Lin-Hui; Guo, Ling-Ling; Wang, Guo-Qing; Zhou, Xi-Ping; Jiang, Yan; Shang, Jing; Murao, Koji; Chen, Jing-Wei; Fu, Wen-Qing; Zhang, Guo-Xing

    2013-01-01

    Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP) mediated immune response, the role of reactive oxygen species (ROS) in brain-skin-axis regulation system remains unknown. The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress) which induced abnormal of hair cycle. Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in CRS mice skin. In addition, SP receptor antagonist (RP67580) reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger) also restored hair cycle, reduced SP protein expression and mast cell activation. Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.

  13. Chronic restraint stress inhibits hair growth via substance P mediated by reactive oxygen species in mice.

    Directory of Open Access Journals (Sweden)

    Nan Liu

    Full Text Available BACKGROUNDS: Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP mediated immune response, the role of reactive oxygen species (ROS in brain-skin-axis regulation system remains unknown. OBJECTIVES: The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress which induced abnormal of hair cycle. METHODS AND RESULTS: Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD and glutathione peroxidase (GSH-Px in CRS mice skin. In addition, SP receptor antagonist (RP67580 reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger also restored hair cycle, reduced SP protein expression and mast cell activation. CONCLUSIONS: Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.

  14. Possibilities and limitations of using historic provenance tests to infer forest species growth responses to climate change

    Science.gov (United States)

    Laura P. Leites; Gerald E. Rehfeldt; Andrew P. Robinson; Nicholas L. Crookston; Barry Jaquish

    2012-01-01

    Under projected changes in global climate, the growth and survival of existing forests will depend on their ability to adjust physiologically in response to environmental change. Quantifying their capacity to adjust and whether the response is species- or population-specific is important to guide forest management strategies. New analyses of historic provenance tests...

  15. Effects of disking, bedding, and subsoiling on survival and growth of three oak species in central Mississippi

    Science.gov (United States)

    J. Paul Jeffreys; Emily B. Schultz; Thomas G. Matney; W. Cade Booth; Jason M. Morris

    2010-01-01

    A replicated split-plot design experiment to evaluate the effects of three site preparation methods (disking, bedding, and subsoiling plus bedding) on survival and growth of three oak species (cherrybark, Quercus pagoda Raf.; Shumard, Quercus shumardii Buckl.; and Nuttall, Quercus texana Buckl.) was established...

  16. Two Positive Periodic Solutions for a Neutral Delay Model of Single-Species Population Growth with Harvesting

    OpenAIRE

    Fang, Hui

    2012-01-01

    By coincidence degree theory for k-set-contractive mapping, this paper establishes a new criterion for the existence of at least two positive periodic solutions for a neutral delay model of single-species population growth with harvesting. An example is given to illustrate the effectiveness of the result.

  17. Two Positive Periodic Solutions for a Neutral Delay Model of Single-Species Population Growth with Harvesting

    Directory of Open Access Journals (Sweden)

    Hui Fang

    2012-01-01

    Full Text Available By coincidence degree theory for k-set-contractive mapping, this paper establishes a new criterion for the existence of at least two positive periodic solutions for a neutral delay model of single-species population growth with harvesting. An example is given to illustrate the effectiveness of the result.

  18. Effect of seed mass on germination and growth in three dominant species in southern Brazilian coastal dunes

    Directory of Open Access Journals (Sweden)

    C. V. CORDAZZO

    Full Text Available The effect of seed mass on germination and growth was tested in fresh-seeds of Blutaparon portulacoides, Panicum racemosum, and Spartina ciliata, selected at random in southern Brazilian populations. The seed mass varied within a population of the three species. Both B. portulacoides and P. racemosum showed normal frequency distribution of seed mass, while S. ciliata did not. Significant differences were observed in seed germination between large and small seeds of all species. In all species the capacity of seedling elongation was greater in seedlings of large seeds than those of small ones. Relative growth rate of seedlings of P. racemosum and S. ciliata decreased with time in all seed mass size-classes. On the other hand, the relative growth rate of B. portulacoides seedlings increased during the first 40 days. Seed mass is an important biological factor, affecting seed germination, seedling elongation, and growth of these species, and favoring large seeds, specially in areas of active sand accretion like coastal dunes.

  19. Effect of seed mass on germination and growth in three dominant species in southern Brazilian coastal dunes

    Directory of Open Access Journals (Sweden)

    CORDAZZO C. V.

    2002-01-01

    Full Text Available The effect of seed mass on germination and growth was tested in fresh-seeds of Blutaparon portulacoides, Panicum racemosum, and Spartina ciliata, selected at random in southern Brazilian populations. The seed mass varied within a population of the three species. Both B. portulacoides and P. racemosum showed normal frequency distribution of seed mass, while S. ciliata did not. Significant differences were observed in seed germination between large and small seeds of all species. In all species the capacity of seedling elongation was greater in seedlings of large seeds than those of small ones. Relative growth rate of seedlings of P. racemosum and S. ciliata decreased with time in all seed mass size-classes. On the other hand, the relative growth rate of B. portulacoides seedlings increased during the first 40 days. Seed mass is an important biological factor, affecting seed germination, seedling elongation, and growth of these species, and favoring large seeds, specially in areas of active sand accretion like coastal dunes.

  20. Influence of topographic aspect, precipitation and drought on radial growth of four major tree species in an Appalachian watershed

    Science.gov (United States)

    Desta Fekedulegn; Ray R., Jr. Hicks; J.J. Colbert

    2003-01-01

    This study used dated and measured tree-ring data to examine relationships between radial growth, topographic aspect, and precipitation for four hardwood species, yellow-poplar (Liriodendron tulipifera L.), northern red oak ( L.), chestnut oak (Quercus prinus L.), and red maple (Acer rubum...

  1. Biomass and leaf-level gas exchange characteristics of three African savanna C4 grass species under optimum growth conditions

    NARCIS (Netherlands)

    Mantlana, K.B.; Veenendaal, E.M.; Arneth, A.; Grispen, V.; Bonyongo, C.M.; Heitkönig, I.M.A.; Lloyd, J.

    2009-01-01

    C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration

  2. Crown structure and growth efficiency of red spruce in uneven-aged, mixed-species stands in Maine

    Science.gov (United States)

    Douglas A. Maguire; John C. Brissette; Lianhong. Gu

    1998-01-01

    Several hypotheses about the relationships among individual tree growth, tree leaf area, and relative tree size or position were tested with red spruce (Picea rubens Sarg.) growing in uneven-aged, mixed-species forests of south-central Maine, U.S.A. Based on data from 65 sample trees, predictive models were developed to (i)...

  3. Elevational plant species richness patterns and their drivers across non-endemics, endemics and growth forms in the Eastern Himalaya.

    Science.gov (United States)

    Manish, Kumar; Pandit, Maharaj K; Telwala, Yasmeen; Nautiyal, Dinesh C; Koh, Lian Pin; Tiwari, Sudha

    2017-09-01

    Despite decades of research, ecologists continue to debate how spatial patterns of species richness arise across elevational gradients on the Earth. The equivocal results of these studies could emanate from variations in study design, sampling effort and data analysis. In this study, we demonstrate that the richness patterns of 2,781 (2,197 non-endemic and 584 endemic) angiosperm species along an elevational gradient of 300-5,300 m in the Eastern Himalaya are hump-shaped, spatial scale of extent (the proportion of elevational gradient studied) dependent and growth form specific. Endemics peaked at higher elevations than non-endemics across all growth forms (trees, shrubs, climbers, and herbs). Richness patterns were influenced by the proportional representation of the largest physiognomic group (herbs). We show that with increasing spatial scale of extent, the richness patterns change from a monotonic to a hump-shaped pattern and richness maxima shift toward higher elevations across all growth forms. Our investigations revealed that the combination of ambient energy (air temperature, solar radiation, and potential evapo-transpiration) and water availability (soil water content and precipitation) were the main drivers of elevational plant species richness patterns in the Himalaya. This study highlights the importance of factoring in endemism, growth forms, and spatial scale when investigating elevational gradients of plant species distributions and advances our understanding of how macroecological patterns arise.

  4. Effect of Hydropriming and Biopriming on Seed Germination and Growth of Two Mexican Fir Tree Species in Danger of Extinction

    Directory of Open Access Journals (Sweden)

    Ramón Zulueta-Rodríguez

    2015-09-01

    Full Text Available Abies spp. in general have been shown to need a period of cold stratification to break dormancy and germinate, but this can be very time consuming. In this study, hydropriming by itself and in combination with biopriming was carried out on Abies hickelii and Abies religiosa seeds. For biopriming, three species of plant growth promoting rhizobacteria ( Pseudomonas fluorescens, P. putida and Bacillus subtilis were tested. The purpose was to determine if germination and growth could be improved for these two endangered species. Our results demonstrated that treating A. hickelii and A. religiosa with both hydropriming and biopriming with certain strains of Plant Growth-Promoting Rhizobacteria (PGPR could improve germination rates up to 91% for A. hickelii and up to 68% for A. religiosa. Importantly, these treatments showed no significant negative impact on the growth of A. religiosa and actually improved growth in A. hickelii. The application of both hydropriming and biopriming offer possibly an alternative methodology to improve germination, survival and preservation of these fir tree species of Mexico that are at risk of extinction.

  5. Impact of competitor species composition on predicting diameter growth and survival rates of Douglas-fir trees in southwestern Oregon

    Science.gov (United States)

    Bravo, Felipe; Hann, D.W.; Maguire, Douglas A.

    2001-01-01

    Mixed conifer and hardwood stands in southwestern Oregon were studied to explore the hypothesis that competition effects on individual-tree growth and survival will differ according to the species comprising the competition measure. Likewise, it was hypothesized that competition measures should extrapolate best if crown-based surrogates are given preference over diameter-based (basal area based) surrogates. Diameter growth and probability of survival were modeled for individual Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees growing in pure stands. Alternative models expressing one-sided and two-sided competition as a function of either basal area or crown structure were then applied to other plots in which Douglas-fir was mixed with other conifers and (or) hardwood species. Crown-based variables outperformed basal area based variables as surrogates for one-sided competition in both diameter growth and survival probability, regardless of species composition. In contrast, two-sided competition was best represented by total basal area of competing trees. Surrogates reflecting differences in crown morphology among species relate more closely to the mechanics of competition for light and, hence, facilitate extrapolation to species combinations for which no observations are available.

  6. Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

    Science.gov (United States)

    Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

    2015-08-01

    Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade

  7. Gas exchange and growth responses to nutrient enrichment in invasive Glyceria maxima and native New Zealand Carex species

    DEFF Research Database (Denmark)

    Sorrell, Brian Keith; Brix, Hans; Fitridge, Isla

    2012-01-01

    , but that its success under nutrient enrichment is a consequence of greater physiological responsiveness and growth plasticity, and stronger integration between gas exchange and growth, coupled with indifference to resource wastage (i.e. low WUE and NUE) at high nutrient supply. The poorer performance of G......We compared photosynthetic gas exchange, the photosynthesis-leaf nitrogen (N) relationship, and growth response to nutrient enrichment in the invasive wetland grass Glyceria maxima (Hartman) Holmburg with two native New Zealand Carex sedges (C. virgata Boott and C. secta Boott), to explore...... the ecophysiological traits contributing to invasive behaviour. The photosynthesis-nitrogen relationship was uniform across all three species, and the maximum light-saturated rate of photosynthesis expressed on a leaf area basis (Amaxa) did not differ significantly between species. However, specific leaf area (SLA...

  8. [Growth, survival and herbivory of seedlings in Brosimum alicastrum (Moraceae), a species from the Neotropical undergrowth].

    Science.gov (United States)

    Ballina-Gómez, H S; Iriarte-Vivar, S; Orellana, R; Santiago, L S

    2008-12-01

    Growth responses, survival, and herbivory, on seedlings of Brosimum alicastrum were studied in a neotropical Mexican forest. We selected 122 seedlings and divided them into three groups assigned to defoliation treatments: control or 0 (n=21), 50 (n=51) and 90% (n=50). Every 4 months during two years we measured seedling growth (in terms of relative growth rate in biomass, leaf area growth, produced leaves and height growth) and survival. In addition, we evaluated every 12 months pathogen damage and insect herbivory using a 2 mm(-2) grid. Separately, we estimated mammal herbivory in 3-month old seedlings that were selected within a plot of 500 m x 10 m (N=1095). Pathogen damage and insect herbivory were evaluated within the same plot in 113 seedlings. We found that 50% defoliated seedlings showed compensatory responses in all growth parameters. Relative growth rate and height growth also had a compensatory response in seedlings at 90% defoliation. Relative growth rate and leaf area growth gradually decreased with time although height growth seedling showed an opposite pattern. Leaves produced were not affected by time. Estimated seedling survival probability increased with defoliation to a maximum of 97%, decreasing at 24 month to 37%. Mammal herbivory was more frequent and severe than herbivory caused by pathogens and insects. In some cases, mammal herbivory produced total defoliation. Compensatory growth in leaf area growth, produced leaves and height growth seedling suggest a synergic compensatory mechanism expressed in a whole-plant growth biomass (relative growth rate). Compensation and survival results suggest trade-offs at the leaf level, such as leaf area growth and produced leaves versus chemical defenses, respectively.

  9. Changes in growth of pristine boreal North American forests from 1950 to 2005 driven by landscape demographics and species traits

    Directory of Open Access Journals (Sweden)

    M. P. Girardin

    2012-07-01

    Full Text Available In spite of the many factors that are occurring and known for positively affecting the growth of forests, some boreal forests across North America have recently felt the adverse impacts of environmental changes. Knowledge of causes for productivity declines in North American boreal forests remains limited, and this is owed to the large spatial and temporal scales involved, and the many plant processes affected. Here, the response of pristine eastern boreal North American (PEBNA forests to ongoing climatic changes is examined using in situ data, community ecology statistics, and species-specific model simulations of carbon exchanges forced by contemporary climatic data. To examine trends in forest growth, we used a recently acquired collection of tree-ring width data from 252 sample plots distributed in PEBNA forests dominated by black spruce (Picea mariana [Mill.] B.S.P. and jack pine (Pinus banksiana Lamb.. Results of linear trend analysis on the tree growth data highlight a dominating forest growth decline in overmature forests (age > 120 years from 1950 to 2005. In contrast, improving growth conditions are seen in jack pine and mature (70–120 years black spruce stands. Multivariate analysis of climate and growth relationships suggests that responses of PEBNA forests to climate are dependent on demographic and species traits via their mediation of temperature and water stress constraints. In support of this hypothesis, the simulation experiment suggests that in old-growth black spruce stands the benefit to growth brought on by a longer growing season may have been low in comparison with the increasing moisture stress and respiration losses caused by warmer summer temperatures. Predicted increases in wildfire frequency in PEBNA forests will likely enhance the positive response of landscape-level forest growth to climate change by shifting the forest distribution to younger age classes while also enhancing the jack pine component.

  10. Native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses.

    Directory of Open Access Journals (Sweden)

    Hoang Hoa Long

    Full Text Available BACKGROUND: All plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. Changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (PGP rhizobacteria which can decrease ethylene (ET levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC deaminase or produce indole acetic acid (IAA. Whether these common PGP mechanisms work similarly for different plant species has not been rigorously tested. METHODOLOGY/PRINCIPAL FINDINGS: We isolated bacterial endophytes from field-grown Solanum nigrum; characterized PGP traits (ACC deaminase activity, IAA production, phosphate solubilization and seedling colonization; and determined their effects on their host, S. nigrum, as well as on another Solanaceous native plant, Nicotiana attenuata. In S. nigrum, a majority of isolates that promoted root growth were associated with ACC deaminase activity and IAA production. However, in N. attenuata, IAA but not ACC deaminase activity was associated with root growth. Inoculating N. attenuata and S. nigrum with known PGP bacteria from a culture collection (DSMZ reinforced the conclusion that the PGP effects are not highly conserved. CONCLUSIONS/SIGNIFICANCE: We conclude that natural endophytic bacteria with PGP traits do not have general and predictable effects on the growth and fitness of all host plants, although the underlying mechanisms are conserved.

  11. Effects of propanil, tebufenozide and mefenacet on growth of four freshwater species of phytoplankton: a microplate bioassay.

    Science.gov (United States)

    Gómez de Barreda Ferraz, D; Sabater, C; Carrasco, J M

    2004-07-01

    The Albufera Natural Park situated in Valencia (Spain), with a very rich flora and fauna is surrounded by rice fields in which pesticide spraying is a regular practice. With this in mind, the sensitivity of four algal species, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila to pesticides propanil, tebufenozide and mefenacet was studied using single species toxicity tests. Organisms were exposed to different concentrations of these herbicides and the algal growth was measured in a microplate reader at 410 nm, at 0, 24, 48 and 72 h. Tebufenozide appeared to be the most inhibitory to Scenedesmus and Chlorella species growth. 72 h EC50 of propanil, tebufenozide and mefenacet ranged from 0.29 to 5.98 mg/l, 0.12 to 0.15 mg/l and from 0.25 to 0.67 mg/l, respectively for the four algal species. The two species of Chlorella were more tolerant than the two species of Scenedesmus.

  12. Characteristics of Armillaria species development and their growth at different temperatures

    Directory of Open Access Journals (Sweden)

    Keča Nenad

    2005-01-01

    Full Text Available Previous research shows that 5 Armillaria species are identified in forest ecosystems in Serbia. This paper presents the Pegler's key of species identification based on fruiting bodies - mushrooms. Previous reference data from Serbia refer only to the species A. mellea. Because of the insufficient information on the bioecology of individual species in the genus Armillaria we studied the effect of temperature, as one of the most important ecological factors for the development of mycelium and rhisomorphs.

  13. High nitrogen and elevated [CO2] effects on the growth, defense and photosynthetic performance of two eucalypt species.

    Science.gov (United States)

    Novriyanti, Eka; Watanabe, Makoto; Kitao, Mitsutoshi; Utsugi, Hajime; Uemura, Akira; Koike, Takayoshi

    2012-11-01

    Atmospheric nitrogen deposition and [CO(2)] are increasing and represent environmental problems. Planting fast-growing species is prospering to moderate these environmental impacts by fixing CO(2). Therefore, we examined the responses of growth, photosynthesis, and defense chemical in leaves of Eucalyptus urophylla (U) and the hybrid of E. deglupta × E. camadulensis (H) to different CO(2) and nitrogen levels. High nitrogen load significantly increased plant growth, leaf N, net photosynthetic rate (A(growth)), and photosynthetic water use efficiency (WUE). High CO(2) significantly increased A(growth), photosynthetic nitrogen use efficiency (PNUE) and WUE. Secondary metabolite (SM, i.e. total phenolics and condensed tannin) was specifically altered; as SM of U increased by high N load but not by elevated [CO(2)], and vice versa for SM of H. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Variation among species in the endocrine control of mammary growth and function: the roles of prolactin, growth hormone, and placental lactogen.

    Science.gov (United States)

    Forsyth, I A

    1986-03-01

    Prolactin, growth hormone, and placental lactogen form a family of structurally related hormones, which may have evolved from a common ancestral peptide. Prolactin and growth hormone are present in all mammals, but the biological activity associated with placental lactogen has been detected in only some groups. Attempts to detect placental lactogen using bioassay and radioreceptor assay are reported and have been unsuccessful in an insectivore (the shrew), a bat, an edentate (the armadillo), a lagomorph (the rabbit), several carnivores (dog, cat, ferret), perissodactyls (horse, zebra, rhino), and, within the artiodactyls, pigs. Placental lactogenic activity has been detected in primates (chimpanzee, orangutan), rodents (voles, Pinon mouse, guinea-pig, mara), and in numerous artiodactyls (llama, giraffe, several species of deer, antelope, gnu, gazelle, musk ox, cape buffalo, Barbary sheep, several sheep of the genus Ovis, goat, and cow). These results confirm and extend the work of others and are discussed in relation to the evolution of these hormones. In synergism with steroid and thyroid hormones, protein hormones of the prolactin and growth hormone family play a crucial role in stimulating the development of the mammary gland, the differentiation and function of mammary cells to secrete milk, and in the systemic adjustments in maternal metabolism in pregnancy and lactation. Studies in vitro have shown that mammary tissues from several species synthesize milk components in response to insulin plus adrenal corticoid plus prolactin. However, there are also species differences in minimal hormonal requirements for lactogenesis. In vivo, for example, rabbits will initiate or sustain lactation in response to prolactin alone, whereas sheep and goats require prolactin plus growth hormone plus adrenal corticoid plus thyroid hormone. Measurement of hormone concentrations in the plasma of pregnant animals shows considerable differences among species in the pattern of

  15. 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.

  16. Influence of nitrogen sources on growth and fermentation performance of different wine yeast species during alcoholic fermentation.

    Science.gov (United States)

    Kemsawasd, Varongsiri; Viana, Tiago; Ardö, Ylva; Arneborg, Nils

    2015-12-01

    In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non-Saccharomyces yeast species (Lachancea thermotolerans, Metschnikowia pulcherrima, Hanseniaspora uvarum and Torulaspora delbrueckii) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were alanine, arginine, asparagine, aspartic acid, glutamine, isoleucine, ammonium sulphate, serine, valine and mixtures of 19 amino acids and of 19 amino acids plus ammonium sulphate (for S. cerevisiae), serine (for L. thermotolerans), alanine (for H. uvarum), alanine and asparagine (for M. pulcherrima), arginine, asparagine, glutamine, isoleucine and mixture of 19 amino acids (for T. delbrueckii). Furthermore, our results showed a clear positive effect of complex mixtures of N-sources on S. cerevisiae and on T. delbrueckii (although to a lesser extent) as to all performance parameters studied, whereas for L. thermotolerans, H. uvarum and M. pulcherrima, single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally, the influences of N-sources observed for T. delbrueckii and H. uvarum resembled those of S. cerevisiae the most and the least, respectively. Overall, this work contributes to an improved understanding of how different N-sources affect growth, glucose consumption and ethanol production of wine-related yeast species under oxygen-limited conditions, which, in turn, may be used to, e.g. optimize growth and fermentation performance of the given yeast upon N-source supplementation during

  17. Carbon uptake, growth and resource-use efficiency in one invasive and six native Hawaiian dry forest tree species.

    Science.gov (United States)

    Stratton, L C; Goldstein, G

    2001-12-01

    Photosynthetic gas exchange, nitrogen- and water-use efficiency, leaf water potential and seasonal patterns of leaf production were studied in seven, dominant dry-forest species from the island of Lana'i, Hawaii, including the rapidly colonizing, non-native Schinus terebinthifolius (Raddi). We evaluated whether unique physiological characteristics of the invasive species explain its capacity to rapidly invade dry forests throughout the Hawaiian Islands. Apparent anomalies in stable carbon isotope data (delta13C) relative to other results led us to study effects of environmental conditions and physiological performance during leaf expansion on delta13C. Species that expanded all their foliage at the beginning of the wet season had more negative leaf delta13C values during the dry season than species with continuous leaf expansion. Among species, S. terebinthifolius had a strong seasonal pattern of leaf production and the most negative delta13C (-29 per thousand). With respect to almost every trait measured, S. terebinthifolius fell at an end of the range of values for the native species. Rapid growth of S. terebinthifolius in this ecosystem may be partially explained by its high maximum CO2 assimilation rates (15 micromol m-2 s-1), low leaf mass per area, high photosynthetic nitrogen-use efficiency per unit leaf mass or area and large decrease in stomatal conductance during the dry season. Relative to the native species, the invasive species exhibited striking phenotypic plasticity, including high rates of stem growth and water and CO2 uptake during the wet season, and maintenance of leaves and high leaf water potentials, as a result of reduced water loss, during the dry season, enabling it to utilize available resources effectively.

  18. Effect of heavy metals combined stress on growth and metals accumulation of three Salix species with different cutting position.

    Science.gov (United States)

    Wang, Wenwen; Wu, Yajing; Akbar, Siddiq; Jia, Xiuqin; He, Zaihua; Tian, Xingjun

    2016-08-02

    This study aimed to compare growth performance and heavy metal (HM) accumulation at different cutting positions of Salix species grown in multi-metal culture. Three Salix species stems cut at different positions (apical to basal) were grown hydroponically for four weeks. The plants were then treated for three weeks with 0, 5, 10, and 20 μM Cd, Cu, Pb, and Zn, resulting in total metal concentrations of 0, 20, 40, and 80 μM. The growth parameters and HM content in shoots and initial cutting were measured. Results showed that, compared with S. fragilis, S. matsudana grew more poorly in uncontaminated condition but grew better and accumulated lower metal in shoots under mixed HM treatment. In addition, cuttings from apical parent stem position exhibited poorer growth performance before and after treatment, as well as greater metal content in shoots than base parts under the HM treatment. These results suggest that S. matsudana may undergo a special mechanism to hinder metals in the initial cutting, thus mitigating growth damage. The apical portion also showed poor resistance against the invasion of mixed HMs because of the immature structure. Therefore, in the selection of phytoremediation plants, metal accumulation ability is not proportional to growth performance.

  19. Asymmetric changes of growth and reproductive investment herald altitudinal and latitudinal range shifts of two woody species.

    Science.gov (United States)

    Matías, Luis; Jump, Alistair S

    2015-02-01

    Ongoing changes in global climate are altering ecological conditions for many species. The consequences of such changes are typically most evident at the edge of the geographical distribution of a species, where range expansions or contractions may occur. Current demographical status at geographical range limits can help us to predict population trends and their implications for the future distribution of the species. Thus, understanding the comparability of demographical patterns occurring along both altitudinal and latitudinal gradients would be highly informative. In this study, we analyse the differences in the demography of two woody species through altitudinal gradients at their southernmost distribution limit and the consistency of demographical patterns at the treeline across a latitudinal gradient covering the complete distribution range. We focus on Pinus sylvestris and Juniperus communis, assessing their demographical structure (density, age and mortality rate), growth, reproduction investment and damage from herbivory on 53 populations covering the upper, central and lower altitudes as well as the treeline at central latitude and northernmost and southernmost latitudinal distribution limits. For both species, populations at the lowermost altitude presented older age structure, higher mortality, decreased growth and lower reproduction when compared to the upper limit, indicating higher fitness at the treeline. This trend at the treeline was generally maintained through the latitudinal gradient, but with a decreased growth at the northern edge for both species and lower reproduction for P. sylvestris. However, altitudinal and latitudinal transects are not directly comparable as factors other than climate, including herbivore pressure or human management, must be taken into account if we are to understand how to infer latitudinal processes from altitudinal data. © 2014 John Wiley & Sons Ltd.

  20. Seasonal trends in growth and biomass accumulation of selected nutrients and metals in six species of emergent aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Behrends, L.L.; Bailey, E.; Bulls, M.J.; Coonrod, H.S.; Sikora, F.J.

    1996-05-01

    Growth and biomass accumulation of selected nutrients and trace metals were monitored for six species of aquatic macrophytes during June, August and November, 1993. Plant species were cultivated in two polyculture treatments, each replicated three times. Polyculture I consisted of Scirpus acutus (hardstem bullrush), Phragmites communes (common reed), and Phalaris arundinacea (canary grass). Polyculture H consisted of Typha spp. (cattail), Scirpus atrovirens (green bullrush), and Scirpus cyperinus (wool grass). Each of the six cells (6 x 9 x 0.6 m), was operated as a gravel-substrate, subsurface-flow wetlands in a continuous recirculating mode. At six week intervals, macro, micro and trace elements were dissolved and added to the sump of the recirculating system. On each of three sampling dates, replicate shoot and root samples were collected, segregated by species and tissue type (roots, rhizomes, stems and leaves), and prepared for gravimetric biomass estimates and chemical analysis. Tissue specific concentrations of N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, were determined on each date for each species and tissue type. Results will be discussed with respect to species specific growth rates, biomass accumulation, and seasonal uptake and translocation of plant nutrients.

  1. Genetic Diversity of Nitrogen-Fixing and Plant Growth Promoting Pseudomonas Species Isolated from Sugarcane Rhizosphere

    Directory of Open Access Journals (Sweden)

    Hai-Bi Li

    2017-07-01

    Full Text Available The study was designed to isolate and characterize Pseudomonas spp. from sugarcane rhizosphere, and to evaluate their plant- growth- promoting (PGP traits and nitrogenase activity. A biological nitrogen-fixing microbe has great potential to replace chemical fertilizers and be used as a targeted biofertilizer in a plant. A total of 100 isolates from sugarcane rhizosphere, belonging to different species, were isolated; from these, 30 isolates were selected on the basis of preliminary screening, for in vitro antagonistic activities against sugarcane pathogens and for various PGP traits, as well as nitrogenase activity. The production of IAA varied from 312.07 to 13.12 μg mL−1 in tryptophan supplemented medium, with higher production in AN15 and lower in CN20 strain. The estimation of ACC deaminase activity, strains CY4 and BA2 produced maximum and minimum activity of 77.0 and 15.13 μmoL mg−1 h−1. For nitrogenase activity among the studied strains, CoA6 fixed higher and AY1 fixed lower in amounts (108.30 and 6.16 μmoL C2H2 h−1 mL−1. All the strains were identified on the basis of 16S rRNA gene sequencing, and the phylogenetic diversity of the strains was analyzed. The results identified all strains as being similar to Pseudomonas spp. Polymerase chain reaction (PCR amplification of nifH and antibiotic genes was suggestive that the amplified strains had the capability to fix nitrogen and possessed biocontrol activities. Genotypic comparisons of the strains were determined by BOX, ERIC, and REP PCR profile analysis. Out of all the screened isolates, CY4 (Pseudomonas koreensis and CN11 (Pseudomonas entomophila showed the most prominent PGP traits, as well as nitrogenase activity. Therefore, only these two strains were selected for further studies; Biolog profiling; colonization through green fluorescent protein (GFP-tagged bacteria; and nifH gene expression using quantitative real-time polymerase chain reaction (qRT-PCR analysis. The

  2. Effects of feed species and HUFA composition on survival and growth of the longsnout seahorse (Hippocampus reidi

    Directory of Open Access Journals (Sweden)

    Patrick eSchubert

    2016-04-01

    Full Text Available Globally, wild seahorse populations are threatened due to, habitat destruction and unsustainable human exploitation among others. Furthermore, aquaculture-based mass-scale rearing is still uncommon due to the low survival rates of seahorse juveniles and exceptionally high feed costs. Previous studies have demonstrated the importance of both highly unsaturated fatty acid (HUFA supplies and a copepod-based rearing for seahorse survival and growth. As the latter is expensive, the question arises as to how high survival rates of seahorse juveniles can be assured under low- to moderate-cost feed regimes. In particular, it remains unknown whether the diet species or their dietary HUFA profiles determine the successful development of seahorse fry.Therefore, the aims of this study were to assess the dependence of growth and survival rates of Hippocampus reidi brood on the animal feed and to infer the impact of feed species vs. dietary HUFA profiles on juvenile growth. A nutrition experiment was conducted where juveniles were treated either with enriched Artemia nauplii (low-cost diet Art or with a mixed diet of Artemia and copepods (moderate-cost diet Art/Cop. Larval survival and growth were analyzed using Cox proportional-hazard and mixed linear model analyses. We found that i both diets enabled good survival, ii diet Art/Cop resulted in superior weight and height growth, and iii the differential effects of diets Art/Cop and Art cannot be explained by their different HUFA compositions alone.From an economical point of view, our findings of high survival rates and relatively high growth rates with the medium-cost treatment Art/Cop may open new possibilities for the large-scale rearing of seahorses. Even the application of a low-cost Art diet might be appropriate for seahorse aquacultures as both survival and growth rates are only marginally lower compared to the former diet.

  3. Survival and growth of parasitic Maculinea alcon caterpillars (Lepidoptera: Lycaenidae) in nests of three Myrmica ant species

    DEFF Research Database (Denmark)

    Nash, D. R.; Als, Thomas Damm; Boomsma, J. J.

    2011-01-01

    The Alcon blue butterfly (Maculinea alcon) parasitizes the nests of several Myrmica ant species. In Denmark, it uses M. rubra and M. ruginodis, but never M. scabrinodis. To further examine the basis of this specificity and local co-adaptation between host and parasite, the pattern of growth...... and survival of newly-adopted caterpillars of M. alcon in Myrmica subcolonies was examined in the laboratory. M. alcon caterpillars were collected from three populations differing in their host use, and reared in laboratory nests of all three ant species collected from each M. alcon population. While......, much higher in nests of M. rubra than in nests of M. ruginodis and M. scabrinodis, even for caterpillars from a population that is never known to use M. rubra as a host in the field. The caterpillars of M. alcon thus do not show local adaptation in their pattern of growth and survival, but instead show...

  4. Growth dynamics of Dracaena cinnabari under controlled conditions as the most effective way to protect endangered species

    OpenAIRE

    Hubálková, Irena; Maděra, Petr; Volařík, Daniel

    2015-01-01

    Dracaena cinnabari Balf. fil. is an endangered endemic species growing on the Yemeni island of Soqotra. Dracaena woodlands are considered as one of the oldest forest communities on Earth. Uncontrolled grazing unfortunately caused a lack of naturally occurring regeneration. Our two-year research was focused on the growth dynamics of Dracaena seedlings from two separate populations. One hundred of germinated seeds from two different altitudes from the island were sown and planted under the same...

  5. Lettuce and rhizosphere microbiome responses to growth promoting Pseudomonas species under field conditions

    NARCIS (Netherlands)

    Cipriano, M.A.P.; Lupatini, M.; Santos, L.; Silva, M. da; Roesch, L.F.W.; Destefano, S.; Freitas, S.; Kuramae, E.E.

    2016-01-01

    Plant growth promoting rhizobacteria (PGPR) are well described and recommended for several crops worldwide. However, one of the most common problems in PGPR research is the difficulty in obtaining reproducible results. Furthermore, few studies have evaluated plant growth promotion and soil microbial

  6. The physical growth of Oreochromis niloticus and three plant species on the aquaponic technology

    Science.gov (United States)

    Mustikasari, A.; Marwoto, P.; Iswari, R. S.

    2018-03-01

    The physical growth of Oreochromis niloticus fish and three types of plants consist of Ipomoea Aquatica, Brassica rapa, and Capsicum annuum on the aquaponic technology have been studied. The aquaponic technology system has been done with 200 fishes m-3, water pump with 15 watts solar energy panel, physical and biological filter, and deep flow technique (DFT). In this study, we have reported that the specific growth rate (SGR), survival (SR), Feed conversion ratio (FCR), and Wet weight (W) are used as the physical growth indicator of Oreochromis niloticus fish, while the length and the number of leaves of plants are used as the physical growth indicator of plants. The physical growth of Oreochromis niloticus fish showed that SGR is 5,56% day-1, SR is 97,67%, FCR is 0,92g and the wet weight is 1220g. The physical growth of the plant in aquaponic technology systems has been compared with the hydroponic treatment systems as controls. Analysis with t-test shows that physical growth of Ipomoea Aquatica and Brassica rapa has no significant difference respectively, whereas Capsicum annuum has significant differences compared with controls. Also, Brassica rapa in the aquaponic technology system shows a more yellow leaf color than the control. Based on these results, we conclude that aquaponic technology system provides effective results for the physical growth of Oreochromis niloticus with Ipomoea Aquatica, while additional nutrients for the both Brassica rapa and Capsicum annuum are required.

  7. Characterization of Alternaria and Penicillium species from similar substrata based on growth at different temperature, pH and water activity

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Frisvad, Jens Christian

    2002-01-01

    Fifty-eight Alternaria isolates representing 10 species or species-groups and 66 Penicillium isolates representing 18 species were examined for their growth response to the combined effects of water activity, temperature and pH in an extended Central Composite Design. Growth responses were recorded...... as colony diameter after one and two weeks of growth and analysed using different multivariate statistical analyses. The isolates, when analysed by principal Component Analysis, clustered according to their genus and to some degree to species or species groups and not according to substratum as excepted...... incubated at two different temperatures were enough to get genus segregation and to some extent species segregation. The results also showed that water activity, temperature and pH interact strongly in their effect on growth rates and that the squared products (optima) of water activity, temperature and p...

  8. Genetically based differentiation in growth of multiple non-native plant species along a steep environmental gradient.

    Science.gov (United States)

    Haider, Sylvia; Kueffer, Christoph; Edwards, Peter J; Alexander, Jake M

    2012-09-01

    A non-native plant species spreading along an environmental gradient may need to adjust its growth to the prevailing conditions that it encounters by a combination of phenotypic plasticity and genetic adaptation. There have been several studies of how non-native species respond to changing environmental conditions along latitudinal gradients, but much less is known about elevational gradients. We conducted a climate chamber experiment to investigate plastic and genetically based growth responses of 13 herbaceous non-native plants along an elevational gradient from 100 to 2,000 m a.s.l. in Tenerife. Conditions in the field ranged from high anthropogenic disturbance but generally favourable temperatures for plant growth in the lower half of the gradient, to low disturbance but much cooler conditions in the upper half. We collected seed from low, mid and high elevations and grew them in climate chambers under the characteristic temperatures at these three elevations. Growth of all species was reduced under lower temperatures along both halves of the gradient. We found consistent genetically based differences in growth over the upper elevational gradient, with plants from high-elevation sites growing more slowly than those from mid-elevation ones, while the pattern in the lower part of the gradient was more mixed. Our data suggest that many non-native plants might respond to climate along elevational gradients by genetically based changes in key traits, especially at higher elevations where low temperatures probably impose a stronger selection pressure. At lower elevations, where anthropogenic influences are greater, higher gene flow and frequent disturbance might favour genotypes with broad ecological amplitudes. Thus the importance of evolutionary processes for invasion success is likely to be context-dependent.

  9. Misinterpretation of Gram Stain from the Stationary Growth Phase of Positive Blood Cultures forBrucellaandAcinetobacterSpecies.

    Science.gov (United States)

    Bazzi, Ali M; Al-Tawfiq, Jaffar A; Rabaan, Ali A

    2017-01-01

    Acinetobacter baumannii and Brucella species are Gram-negative organisms that are vulnerable to misinterpretation as Gram-positive or Gram-variable in blood cultures. We assess the random errors in gram stain interpretation to reduce the likelihood of such errors and therefore patient harm. Aerobic and anaerobic blood cultures from two patients in an acute care facility in Saudi Arabia were subjected to preliminary Gram-staining. In case 1, VITEK-2 Anaerobe Identification, repeat Gram staining from a blood agar plate, Remel BactiDrop™ Oxidase test, Urea Agar urease test and real-time PCR were used to confirm presence of Brucella and absence of Coryneform species. In case 2, repeat Gram- staining from the plate and the vials, VITEK-2 Gram-Negative Identification, real-time PCR and subculture on to Columbia agar, blood agar, and MacConkey agar were carried out to identify A. baumannii . In case 1, initially pleomorphic Gram-positive bacteria were identified. Coryneform species were suspected. Tiny growth was observed after 24 h on blood agar plates, and good growth by 48 h. Presence of Brucella species was ultimately confirmed. In case 2, preliminary Gram-stain results suggested giant Gram-positive oval cocci. Further testing over 18-24 h identified A. baumannii . Oxidase test from the plate and urease test from the culture vial is recommended after apparent identification of pleomorphic Gram-positive bacilli from blood culture, once tiny growth is observed, to distinguish Brucella from Corynebacterium species. If giant Gram-positive oval cocci are indicated by preliminary Gram-staining, it is recommended that the Gram stain be repeated from the plate after 4-6 h, or culture should be tested in Triple Sugar Iron (TSI) medium and the Gram stain repeated after 2-4 h incubation.

  10. Mycelial growth rate and macro- and micromorphological characteristics of medicinal species of genus Ganoderma (higher Basidiomycetes) from Iran.

    Science.gov (United States)

    Keypour, Somayeh; Riahi, Hossein; Safaie, Naser; Borhani, Ali

    2014-01-01

    Mycelial growth rate is a distinguishing quality that demonstrates continuous variation in different isolates collected from various hosts and locations. The objectives of this research were (1) to reinvestigate the previous identification of Iranian species, and (2) to recognize the best native isolate(s) for cultivation of different Ganoderma species. Of 78 samples collected from different hosts and sites, only 43 mycelia could be purified and examined for further study. Growth rate (GR; Δd/Δt) and growth coefficient (GC; dgh/t) were analyzed by growing isolate culture on 2% malt-extract agar medium (pH 5.5) incubated at 25°C. Macro- and micromorphological studies on mycelia and fruiting bodies such as basidiospore and cutis microcharacters as well as fruiting body quality were used for precise identification. Results revealed that samples belonged to 4 species: G. lucidum, G. applanatum, G. resinaceum, and G. australe. Among all samples, the isolate morphologically identified as G. applanatum showed the best GR (12 mm/day) and good GC (128 mm/day), followed by the 2 other isolates identified as G. resinaceum (GRs and GCs of 11 and 55 mm/day and 10.9 and 43.6 mm/day, respectively).

  11. Growth of mycotal species on the eggs of Cyprinus carpio in ...

    African Journals Online (AJOL)

    The smallest number of those species was found on the eggs of common carp in water from Spring Cypisek, Pond Komosa and River Suprasl, which are low in biogenes (12, ... The following rare mycotal species were also found: Allomyces arbuscula, Aphanomyces frigidophilus, Candida albicans, Fusarium aquaeductum, ...

  12. The presence and growth of Legionella species in thermostatic shower mixer taps: an exploratory field study

    NARCIS (Netherlands)

    Joost van Hoof; P.W.J.J. van der Wielen; E. van der Blom; O.W.W. Nuijten; L. Hornstra

    2014-01-01

    Legislation in the Netherlands requires routine analysis of drinking water samples for cultivable Legionella species from high-priority installations. A field study was conducted to investigate the presence of Legionella species in thermostatic shower mixer taps. Water samples and the interior of

  13. Effects of salinity on growth of plant species from terrestrializing fens

    NARCIS (Netherlands)

    Stofberg, S.F.; Klimkovska, A.; Paulissen, M.P.C.P.; Witte, J.Ph.M.; Zee, van der S.E.A.T.M.

    2015-01-01

    Terrestrializing lowland fens may be temporarily exposed to elevated surface water salinity, which may have serious consequences for nature conservation. We investigated the response of five fresh water fen plant species to elevated salinity. In a controlled greenhouse experiment, these species were

  14. Growth of mycotal species on the eggs of Cyprinus carpio in ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-02-11

    Feb 11, 2015 ... on the eggs of cyprinid species such as Chondrostoma nasus, Gobio albipinatus and Scardinus erythrophthalmus. (Czeczuga and Muszynska, 1999). A. arbuscula has also been isolated from the eggs of C. carpio on a fish farm in. Thailand (Chukanhom and Hatai, 2004). Other species from the Allomyces ...

  15. Effects of mycorrhizal species on colonization, polyphenol levels, and growth characteristics of Allium porrum

    Science.gov (United States)

    The effects of different mycorrhizal fungi species (Rhizopus intraradices, Gigapora margarita, Glomus geosporum, Paraglomus occultum, Claroideoglomus claroideum, white Glomus species) on their ability to colonize leek roots (Allium porrum) and the effect of symbiosis on changes in the levels of poly...

  16. Control of reactive oxygen species (ROS production through histidine kinases in Aspergillus nidulans under different growth conditions

    Directory of Open Access Journals (Sweden)

    Saki Hayashi

    2014-01-01

    Full Text Available Sensor histidine kinases (HKs are important factors that control cellular growth in response to environmental conditions. The expression of 15 HKs from Aspergillus nidulans was analyzed by quantitative real-time PCR under vegetative, asexual, and sexual growth conditions. Most HKs were highly expressed during asexual growth. All HK gene-disrupted strains produced reactive oxygen species (ROS. Three HKs are involved in the control of ROS: HysA was the most abundant under the restricted oxygen condition, NikA is involved in fungicide sensing, and FphA inhibits sexual development in response to red light. Phosphotransfer signal transduction via HysA is essential for ROS production control.

  17. Lettuce and rhizosphere microbiome responses to growth promoting Pseudomonas species under field conditions.

    Science.gov (United States)

    Cipriano, Matheus A P; Lupatini, Manoeli; Lopes-Santos, Lucilene; da Silva, Márcio J; Roesch, Luiz F W; Destéfano, Suzete A L; Freitas, Sueli S; Kuramae, Eiko E

    2016-12-01

    Plant growth promoting rhizobacteria are well described and recommended for several crops worldwide. However, one of the most common problems in research into them is the difficulty in obtaining reproducible results. Furthermore, few studies have evaluated plant growth promotion and soil microbial community composition resulting from bacterial inoculation under field conditions. Here we evaluated the effect of 54 Pseudomonas strains on lettuce (Lactuca sativa) growth. The 12 most promising strains were phylogenetically and physiologically characterized for plant growth-promoting traits, including phosphate solubilization, hormone production and antagonism to pathogen compounds, and their effect on plant growth under farm field conditions. Additionally, the impact of beneficial strains on the rhizospheric bacterial community was evaluated for inoculated plants. The strains IAC-RBcr4 and IAC-RBru1, with different plant growth promoting traits, improved lettuce plant biomass yields up to 30%. These two strains also impacted rhizosphere bacterial groups including Isosphaera and Pirellula (phylum Planctomycetes) and Acidothermus, Pseudolabrys and Singusphaera (phylum Actinobacteria). This is the first study to demonstrate consistent results for the effects of Pseudomonas strains on lettuce growth promotion for seedlings and plants grown under tropical field conditions. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Adaptation of Trichoderma Species to Pesticide Confidor and Evaluation of their Growth Ability in the Media Containing Confidor

    Directory of Open Access Journals (Sweden)

    Farnaz Ershadfath

    2015-12-01

    Full Text Available Introduction: Contamination caused by pesticides is considered as one of the environmental problems. Bioremediation is exploiting the ability of microorganisms to remove pollutants. Trichoderma species are free-living fungi that exist naturally in the environment. These fungi have the ability to uptake some contaminants biologically. The aim of this study is to evaluate the effect of Confidor, as an environmental contaminant, on the growth ability of Trichoderma sp. as a contaminant absorber. Materials and methods: Five species of Trichoderma fungi were cultured in PDA media. Then the fungi were adapted with 3 different concentrations of Confidor gradually (5, 10 and 20 mg/l. The diameter of the fungal colonies growing in different concentrations of the toxin, were measured after 24 hr and were compared with the control samples (medium without toxin. Results: Results showed that in all species of fungi the colony diameters increased significantly with increasing toxin concentrations. The largest colony diameter was related to T.tomentosum, T.asperellum and T.harzianum (88.88, 87.5 and 86.95%, respectively at the concentration of 20 mg of toxic. Also, in all studied fungal species, in the medium containing 20 (mg/ l of toxic, the aerial hyphae expanded much thicker and faster than other concentrations. Discussion and conclusion: The results indicate a significant increase in the growth ability of Trichoderma strains with increasing Confidor concentration. Therefore it could be concluded that Trichoderma fungi have a high potentiality for biodegradation of Confidor.

  19. BASAL MEDIA FORMULATION USING CANAVALIA ENSIFORMIS AS CARBON AND NITROGEN SOURCE FOR THE GROWTH OF SOME FUNGI SPECIES

    Directory of Open Access Journals (Sweden)

    B.J. Akinyele2

    2012-02-01

    Full Text Available The possibility of developing alternative media to commercial potato dextrose agar was assessed using, Canavalia ensiformis (Linn (jack beans as carbon and nitrogen source. Six leguminous meal media were used as substitute for either carbon or nitrogen or both, while potato dextrose broth (PDB was used as a positive control and basal medium as a negative control. Six species of fungi Aspergillus flavus, A. niger, Meria coniospora, Mucor sp, Neurospora crassa and Rhizopus oryzae were aseptically inoculated into the formulated media and allowed to grow. Their mycelia dry weights were taken after 24, 48, 72, 96 and 120 hours. Growth of all fungal species was observed to be slightly lower, about the same or better in the formulated media relative to the control. Aspergillus flavus had its highest biomass of 1.70g in the media formulated with Canavalia ensiformis as the carbon source relative to 1.42g as the standard at the 120 hour. A. niger had a growth of 0.62g relative to 0.61g at 120 hours of the control. Meria coniospora had a growth of 0.27g relative to 0.38g at 120 hours. Mucor sp had a growth of 0.54g relative to 0.44g at 120 hours. Neurospora crassa had a growth of 1.05g relative to 0.24g at 120 hours. Rhizopus oryzae had a growth of 0.14g relative to 0.25g at 120 hours. The study revealed that Canavalia ensiformis contains minerals and nutrients that is able to provide the nutritional requirements of these fungi. Thus, it can be used as an alternative material in the preparation of culture media for in vitro cultivation of these fungi for teaching and research purposes.

  20. Species characteristics and intraspecific variation in growth and photosynthesis of Cryptomeria japonica under elevated O3 and CO2.

    Science.gov (United States)

    Hiraoka, Yuichiro; Iki, Taiichi; Nose, Mine; Tobita, Hiroyuki; Yazaki, Kenichi; Watanabe, Atsushi; Fujisawa, Yoshitake; Kitao, Mitsutoshi

    2017-06-01

    In order to predict the effects of future atmospheric conditions on forest productivity, it is necessary to clarify the physiological responses of major forest tree species to high concentrations of ozone (O3) and carbon dioxide (CO2). Furthermore, intraspecific variation of these responses should also be examined in order to predict productivity gains through tree improvements in the future. We investigated intraspecific variation in growth and photosynthesis of Cryptomeria japonica D. Don, a major silviculture species in Japan, in response to elevated concentrations of O3 (eO3) and CO2 (eCO2), separately and in combination. Cuttings of C. japonica were grown and exposed to two levels of O3 (ambient and twice-ambient levels) in combination with two levels of CO2 (ambient and 550 µmol mol-1 in the daytime) for two growing seasons in a free-air CO2 enrichment experiment. There was no obvious negative effect of eO3 on growth or photosynthetic traits of the C. japonica clones, but a positive effect was observed for annual height increments in the first growing season. Dry mass production and the photosynthetic rate increased under eCO2 conditions, while the maximum carboxylation rate decreased. Significant interaction effects of eO3 and eCO2 on growth and photosynthetic traits were not observed. Clonal effects on growth and photosynthetic traits were significant, but the interactions between clones and O3 and/or CO2 treatments were not. Spearman's rank correlation coefficients between growth traits under ambient conditions and for each treatment were significantly positive, implying that clonal ranking in growth abilities might not be affected by either eO3 or eCO2. The knowledge obtained from this study will be helpful for species selection in afforestation programs, to continue and to improve current programs involving this species, and to accurately predict the CO2 fixation capacity of Japanese forests. © The Author 2017. Published by Oxford University Press. All

  1. Growth responses of woody species to long- and short-term fumigation with sulfur dioxide

    Science.gov (United States)

    Keith F. Jensen; Leon S. Dochinger

    1979-01-01

    Height growth of silver maple, white ash, yellow-poplar, sycamore, eastern cottonwood, and white spruce seedlings was not significantly influenced by 0.15 ppm SO2 for 8 hours/day, 5 days/week. A fumigation treatment of 0.25 ppm SO2 for 8 hourd/day, 5 days/week did not significantly affect height growth of black alder,...

  2. Parametric scaling from species to growth-form diversity: an interesting analogy with multifractal functions.

    Science.gov (United States)

    Ricotta, Carlo; Pacini, Alessandra; Avena, Giancarlo

    2002-01-01

    We propose a measure of divergence from species to life-form diversity aimed at summarizing the ecological similarity among different plant communities without losing information on traditional taxonomic diversity. First, species and life-form relative abundances within a given plant community are determined. Next, using Rényi's generalized entropy, the diversity profiles of the analyzed community are computed both from species and life-form relative abundances. Finally, the speed of decrease from species to life-form diversity is obtained by combining the outcome of both profiles. Interestingly, the proposed measure shows some formal analogies with multifractal functions developed in statistical physics for the analysis of spatial patterns. As an application for demonstration, a small data set from a plant community sampled in the archaeological site of Paestum (southern Italy) is used.

  3. Species distribution models predict temporal but not spatial variation in forest growth

    NARCIS (Netherlands)

    Maaten, van der Ernest; Hamann, A.; Maaten-Theunissen, van der M.; Bergsma, A.R.; Hengeveld, G.M.; Lammeren, van R.J.A.; Mohren, G.M.J.; Nabuurs, G.J.; Terhürne, R.L.; Sterck, F.J.

    2017-01-01

    Bioclimate envelope models have been widely used to illustrate the discrepancy between current species distributions and their potential habitat under climate change. However, the realism and correct interpretation of such projections has been the subject of considerable discussion. Here, we

  4. Crosstalk between sugarcane and a plant-growth promoting Burkholderia species

    OpenAIRE

    Chanyarat Paungfoo-Lonhienne; Thierry G. A. Lonhienne; Yun Kit Yeoh; Bogdan C. Donose; Richard I. Webb; Jeremy Parsons; Webber Liao; Evgeny Sagulenko; Prakash Lakshmanan; Philip Hugenholtz; Susanne Schmidt; Mark A. Ragan

    2016-01-01

    Bacterial species in the plant-beneficial-environmental clade of Burkholderia represent a substantial component of rhizosphere microbes in many plant species. To better understand the molecular mechanisms of the interaction, we combined functional studies with high-resolution dual transcriptome analysis of sugarcane and root-associated diazotrophic Burkholderia strain Q208. We show that Burkholderia Q208 forms a biofilm at the root surface and suppresses the virulence factors that typically t...

  5. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

    Directory of Open Access Journals (Sweden)

    Erika Acosta-Smith

    2018-01-01

    Full Text Available Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species.

  6. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

    Science.gov (United States)

    Acosta-Smith, Erika; Viveros-Jiménez, Karina; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Bolscher, Jan G. M.; Nazmi, Kamran; Flores-Villaseñor, Hector; Alapizco-Castro, Gerardo; de la Garza, Mireya; Martínez-Garcia, Jesús J.; Velazquez-Roman, Jorge; Leon-Sicairos, Nidia

    2018-01-01

    Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species. PMID:29375503

  7. Quantifying in situ growth rate of a filamentous bacterial species in activated sludge using rRNA:rDNA ratio.

    Science.gov (United States)

    Nguyen, Vivi L; He, Xia; de Los Reyes, Francis L

    2016-11-01

    If the in situ growth rate of filamentous bacteria in activated sludge can be quantified, researchers can more accurately assess the effect of operating conditions on the growth of filaments and improve the mathematical modeling of filamentous bulking. We developed a method to quantify the in situ specific growth rate of Sphaerotilus natans (a model filament) in activated sludge using the species-specific 16S rRNA:rDNA ratio. Primers targeting the 16S rRNA of S. natans were designed, and real-time PCR and RT-PCR were used to quantify DNA and RNA levels of S. natans, respectively. A positive linear relationship was found between the rRNA:rDNA ratio (from 440 to 4500) and the specific growth rate of S. natans (from 0.036 to 0.172 h -1 ) using chemostat experiments. The in situ growth rates of S. natans in activated sludge samples from three water reclamation facilities were quantified, illustrating how the approach can be applied in a complex environment such as activated sludge. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Aromatic Amino Acid-Derived Compounds Induce Morphological Changes and Modulate the Cell Growth of Wine Yeast Species.

    Science.gov (United States)

    González, Beatriz; Vázquez, Jennifer; Cullen, Paul J; Mas, Albert; Beltran, Gemma; Torija, María-Jesús

    2018-01-01

    Yeasts secrete a large diversity of compounds during alcoholic fermentation, which affect growth rates and developmental processes, like filamentous growth. Several compounds are produced during aromatic amino acid metabolism, including aromatic alcohols, serotonin, melatonin, and tryptamine. We evaluated the effects of these compounds on growth parameters in 16 different wine yeasts, including non- Saccharomyces wine strains, for which the effects of these compounds have not been well-defined. Serotonin, tryptamine, and tryptophol negatively influenced yeast growth, whereas phenylethanol and tyrosol specifically affected non- Saccharomyces strains. The effects of the aromatic alcohols were observed at concentrations commonly found in wines, suggesting a possible role in microbial interaction during wine fermentation. Additionally, we demonstrated that aromatic alcohols and ethanol are able to affect invasive and pseudohyphal growth in a manner dependent on nutrient availability. Some of these compounds showed strain-specific effects. These findings add to the understanding of the fermentation process and illustrate the diversity of metabolic communication that may occur among related species during metabolic processes.

  9. Aromatic Amino Acid-Derived Compounds Induce Morphological Changes and Modulate the Cell Growth of Wine Yeast Species

    Directory of Open Access Journals (Sweden)

    Beatriz González

    2018-04-01

    Full Text Available Yeasts secrete a large diversity of compounds during alcoholic fermentation, which affect growth rates and developmental processes, like filamentous growth. Several compounds are produced during aromatic amino acid metabolism, including aromatic alcohols, serotonin, melatonin, and tryptamine. We evaluated the effects of these compounds on growth parameters in 16 different wine yeasts, including non-Saccharomyces wine strains, for which the effects of these compounds have not been well-defined. Serotonin, tryptamine, and tryptophol negatively influenced yeast growth, whereas phenylethanol and tyrosol specifically affected non-Saccharomyces strains. The effects of the aromatic alcohols were observed at concentrations commonly found in wines, suggesting a possible role in microbial interaction during wine fermentation. Additionally, we demonstrated that aromatic alcohols and ethanol are able to affect invasive and pseudohyphal growth in a manner dependent on nutrient availability. Some of these compounds showed strain-specific effects. These findings add to the understanding of the fermentation process and illustrate the diversity of metabolic communication that may occur among related species during metabolic processes.

  10. Complete nutrient content of four species of commercially available feeder insects fed enhanced diets during growth.

    Science.gov (United States)

    Finke, Mark D

    2015-11-01

    Commercially raised feeder insects used to feed captive insectivores are a good source of many nutrients but are deficient in several key nutrients. Current methods used to supplement insects include dusting and gut-loading. Here, we report on the nutrient composition of four species of commercially raised feeder insects fed a special diet to enhance their nutrient content. Crickets, mealworms, superworms, and waxworms were analyzed for moisture, crude protein, fat, ash, acid detergent fiber, total dietary fiber, minerals, amino acids, fatty acids, vitamins, taurine, carotenoids, inositol, and cholesterol. All four species contained enhanced levels of vitamin E and omega 3 fatty acids when compared to previously published data for these species. Crickets, superworms, and mealworms contained β-carotene although using standard conversion factors only crickets and superworms would likely contain sufficient vitamin A activity for most species of insectivores. Waxworms did not contain any detectable β-carotene but did contain zeaxanthin which they likely converted from dietary β-carotene. All four species contained significant amounts of both inositol and cholesterol. Like previous reports all insects were a poor source of calcium and only superworms contained vitamin D above the limit of detection. When compared to the nutrient requirements as established by the NRC for growing rats or poultry, these species were good sources of most other nutrients although the high fat and low moisture content of both waxworms and superworms means when corrected for energy density these two species were deficient in more nutrients than crickets or mealworms. These data show the value of modifying the diet of commercially available insects as they are growing to enhance their nutrient content. They also suggest that for most insectivores properly supplemented lower fat insects such as crickets, or smaller mealworms should form the bulk of the diet. © 2015 The Authors. Zoo Biology

  11. Effects of Propionibacterium on the growth and mycotoxin production by some species of Fusarium and Alternaria.

    Science.gov (United States)

    Gwiazdowska, Daniela; Czaczyk, Katarzyna; Filipiak, Marian; Gwiazdowski, Romuald

    2008-01-01

    The aim of this research was to study the antifungal properties of propionibacteria. Three fractions from cultures of Propionibacterium freudenreichii ssp. shermanii 41 and ssp. freudenreichii 111 (i.e. culture containing viable bacteria, cell-free supernatant and bacteriocin preparation) were tested for their ability to inhibit the growth and mycotoxin production of Alternaria alternata, Fusarium culmorum, Fusarium graminearum and Fusarium verticillioides. The growth of the fungi was monitored during cultivation using a plating method. The concentration of toxins produced was measured by HPLC on the 14th day of culture. Altenuene and tenuazonic acid were determined in cultures of A. alternata whilst concentration of nivalenol, deoxynivalenol, fumonisin B1 and zearalenone was measured in Fusarium cultures. The strongest inhibition of growth and toxin production was observed in the presence of cultures containing viable cells and supernatants obtained from propionibacteria cultures. The bacteriocin extracts generally had a weak fungistatic effect on the growth of A. alternata, F. culmorum and F. graminearum. Despite the fact that growth was slower in the presence of bacteriocin extracts than in control trials, none of the preparations prepared from the propionibacteria significantly reduced the level of mycotoxin production. The ability of P. freudenreichii ssp. freudenreichii 111 to remove zearalenone from liquid medium was also evaluated. It was shown that both viable and non-viable cells caused a decrease in zearalenone concentration in the medium.

  12. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    Directory of Open Access Journals (Sweden)

    Hooz A Mendivelso

    Full Text Available A seasonal period of water deficit characterizes tropical dry forests (TDFs. There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

  13. Growth rate variation among passerine species in tropical and temperate sites: an antagonistic interaction between parental food provisioning and nest predation risk

    Science.gov (United States)

    Martin, Thomas E.; Llyod, Penn; Bosque, Carlos; Barton, Daniel C.; Biancucci, Atilio L.; Cheng, Yi-Ru; Ton, Riccardo

    2011-01-01

    Causes of interspecific variation in growth rates within and among geographic regions remain poorly understood. Passerine birds represent an intriguing case because differing theories yield the possibility of an antagonistic interaction between nest predation risk and food delivery rates on evolution of growth rates. We test this possibility among 64 Passerine species studied on three continents, including tropical and north and south temperate latitudes. Growth rates increased strongly with nestling predation rates within, but not between, sites. The importance of nest predation was further emphasized by revealing hidden allometric scaling effects. Nestling predation risk also was associated with reduced total feeding rates and per-nestling feeding rates within each site. Consequently, faster growth rates were associated with decreased per-nestling food delivery rates across species, both within and among regions. These relationships suggest that Passerines can evolve growth strategies in response to predation risk whereby food resources are not the primary limit on growth rate differences among species. In contrast, reaction norms of growth rate relative to brood size suggest that food may limit growth rates within species in temperate, but not tropical, regions. Results here provide new insight into evolution of growth strategies relative to predation risk and food within and among species.

  14. [Effects of NaCl stress on the seedling growth and K(+)- and Na(+) -allocation of four leguminous tree species].

    Science.gov (United States)

    Mo, Hai-Bo; Yin, Yun-Long; Lu, Zhi-Guo; Wei, Xiu-Jun; Xu, Jian-Hua

    2011-05-01

    Taking the pot-cultured seedlings of four leguminous tree species (Albizia julibrissin, Robinia pseudoacacia, Sophora japonica, and Gleditsia sinensis) as test materials, this paper studied their growth indices, critical salt concentration (C50), and K+ and Na+ allocation under different levels of NaCl stress, aimed to understand the difference of test tree species in salt tolerance. NaCl stress inhibited the seedling growth of the tree species. Under NaCl stress, the dry matter accumulation decreased, while the root/shoot ratio increased, especially for A. julibrissin and G. sinensis. Quadratic regression analysis showed that the C50 of A. julibrissin, R. pseudoacacia, S. japonica, and G. sinensis was 3.0 per thousand, 5.0 per thousand, 4.5 per thousand, and 3.9 per thousand, respectively, i.e., the salt tolerance of the four tree species was in the order of R. pseudoacacia > S. japonica > G. sinensis > A. julibrissin. In the root, stem, and leaf of the four tree species seedlings, the Na+ content increased with the increase of NaCl stress, while the K+ content (except in the root of A. julibrissin) decreased after an initial increase, resulting in a larger difference in the K+/Na+ ratio in the organs. Under the same NaCl stress, the allocation of Na+ in different organs of the four tree species seedlings decreased in the order of root>stem>leaf, while that of K+ differed with tree species and NaCl stress, and leaf was the main storage organ for K+. The K+/Na+ ratio in different organs decreased in the sequence of leaf>stem>root. R. pseudoacacia under NaCl stress accumulated more K+ and less Na+ in stem and leaf, and had higher K+/Na+ ratio in all organs and higher dry mass, being assessed to be more salt-tolerant. In contrast, A. julibrissin under high NaCl stress accumulated more Na+ in stem and leaf, and had a lower K+/Na+ ratio in all organs and lower dry mass, being evaluated to be lesser salt-tolerant. The K+ accumulation in seedling stem and leaf and the Na

  15. [Effects of shading on two Sphagnum species growth and their interactions].

    Science.gov (United States)

    Ma, Jin-Ze; Bu, Zhao-Jun; Zheng, Xing-Xing; Li, Shan-Lin; Zeng, Jing; Zhao, Gao-Lin

    2012-02-01

    Taking Sphagnum palustre and S. fallax as test materials, this paper studied their growth and interactions under shading. In monoculture, shading promoted the height growth of S. palustre markedly, but had no effect on the growth of S. fallax and the biomass and branching of S. palustre. In mixed culture, S. fallax suppressed the increase of biomass and branching of S. palustre, while S. palustre had no effects on S. fallax. With the increase of shading stress, the competition of neighbour on S. fallax intensified. When the stress increased further, neighbor effect on S. fallax tended to be positive. However, the effect of neighbour on S. palustre was always competitive and did not change with the increase of shading stress.

  16. SEEDLING GROWTH OF RAINFOREST SPECIES INOCULATED WITH ARBUSCULAR MYCORRHIZAL FUNGI: AN ANALYSIS OF THE SIZE FRAGMENT EFFECT

    Directory of Open Access Journals (Sweden)

    Javier Francisco Álvarez-Sánchez

    2013-11-01

    Full Text Available Deforestation is a process that brings as a consequence strong environmental problems in tropical rain forests. Restoration of damaged areas can accelerate succession process and improve seedling performance. One way to reach this objective is to inoculate them with native arbuscular mycorrhizal fungi. This study analyzed the effect of mycorrhizae inoculation on seedling survivorship and growth of two tree species, Pleuranthodendron lindenii (light demanding and Pimenta dioica (shade tolerant in shaded greenhouse and field conditions in the region of "Los Tuxtlas", Veracruz. We applied three inoculation treatments, without mycorrhizal inoculum (control, mycorrhizal inoculum from small fragments, and inoculum from large fragments. We analyzed survivorship and relative growth rates for height and diameter. For both species, significant differences (p<0.05 in growth rates in height and diameter were found for inoculum origin and time, as well as their interaction. The highest mean values corresponded to plants with inoculum from small fragments. Differences in survival among arbuscular mycorrhizal fungi treatments were significant only under shaded greenhouse conditions. The results are discussed in terms of life history traits and environmental conditions.

  17. Control of active nitrogen species used for PA-MBE growth of group III nitrides on Si

    Science.gov (United States)

    Ohachi, Tadashi; Yamabe, Nobuhiko; Yamamoto, Yuka; Wada, Motoi; Ariyada, Osamu

    2011-03-01

    A new spiral parallel mesh electrode (PME) is presented to control active nitrogen species in plasma-assisted molecular beam epitaxial (PA-MBE) growth of group III nitrides and their alloys. Direct flux of active nitrogen from radio frequency inductive coupled plasma (rf-ICP) discharge was able to be measured using a mesh electrode for filtering charge particles and electron emission due to the self-ionization of nitrogen atoms on a negatively biased electrode. In situ measurement of direct nitrogen atom fluxes using the spiral PME during PA-MBE growth of GaN and AlN on Si substrates is investigated. A linear rf power dependence of direct flux of active species on atoms such as nitrogen (N+N*), where N and N* were ground and excited atoms, respectively, from a rf-ICP was confirmed by the spiral PME. An indirect flux of nitrogen adsorbed (ADS) atoms (N+N*) during discharge was also monitored by the spiral PME and received influence of the wall surface of the growth chamber. ADS nitrogen atoms are able to be used for nitridation of Si surface to grow a double buffer layer (DBL) AlN/β-Si3N4/Si.

  18. Comparative physiology of allopatric Populus species: geographic clines in photosynthesis, height growth, and carbon isotope discrimination in common gardens

    Science.gov (United States)

    Soolanayakanahally, Raju Y.; Guy, Robert D.; Street, Nathaniel R.; Robinson, Kathryn M.; Silim, Salim N.; Albrectsen, Benedicte R.; Jansson, Stefan

    2015-01-01

    Populus species with wide geographic ranges display strong adaptation to local environments. We studied the clinal patterns in phenology and ecophysiology in allopatric Populus species adapted to similar environments on different continents under common garden settings. As a result of climatic adaptation, both Populus tremula L. and Populus balsamifera L. display latitudinal clines in photosynthetic rates (A), whereby high-latitude trees of P. tremula had higher A compared to low-latitude trees and nearly so in P. balsamifera (p = 0.06). Stomatal conductance (gs) and chlorophyll content index (CCI) follow similar latitudinal trends. However, foliar nitrogen was positively correlated with latitude in P. balsamifera and negatively correlated in P. tremula. No significant trends in carbon isotope composition of the leaf tissue (δ13C) were observed for both species; but, intrinsic water-use efficiency (WUEi) was negatively correlated with the latitude of origin in P. balsamifera. In spite of intrinsically higher A, high-latitude trees in both common gardens accomplished less height gain as a result of early bud set. Thus, shoot biomass was determined by height elongation duration (HED), which was well approximated by the number of days available for free growth between bud flush and bud set. We highlight the shortcoming of unreplicated outdoor common gardens for tree improvement and the crucial role of photoperiod in limiting height growth, further complicating interpretation of other secondary effects. PMID:26236324

  19. Growth of Candida species in liquid culture medium for Trichomonas vaginalis.

    OpenAIRE

    Erdman, Y J; Holton, J M; Becker, A

    1984-01-01

    The growth of Candida spp from vaginal specimens in Bushby's liquid medium for T vaginalis was compared with that on Sabouraud's agar medium, and isolation was significantly greater in Bushby's medium (p less than 0.001). Isolations missed (4.43%) in Bushby's medium probably represented vaginal carriage of small numbers of Candida spp.

  20. Pig epidermal growth factor precursor contains segments that are highly conserved among species

    DEFF Research Database (Denmark)

    Jørgensen, P E; Jensen, L.G.; Sørensen, B S

    1998-01-01

    The 53-aa polypeptide epidermal growth factor (EGF) is synthesized as a 1200-aa precursor. The non-EGF part of the precursor is very long compared with EGF, and can therefore be expected to have a biological role of its own. We have sequenced cDNA of the pig EGF precursor and compared a 668-aa...

  1. Transient negative biochar effects on plant growth are strongest after microbial species loss

    NARCIS (Netherlands)

    Hol, (Gera) W.H.G.; Vestergård, M.; Ten Hooven, F.C.; Duyts, H.; Van de Voorde, T.F.J.; Bezemer, T. Martijn

    2017-01-01

    Biochar has been explored as an organic amendment to improve soil quality and benefit plant growth. The overall positive effects of biochar on crop yields are generally attributed to abiotic changes, while the alternative causal pathway via changes in soil biota is unexplored. We compared plant

  2. Nursery growth and biomass of the seedlings of nine tree species ...

    African Journals Online (AJOL)

    The production of quality seedlings depends on the potting media. A nursery experiment was conducted in Pawe Agricultural Research Centre, in the northwest part of Ethiopia in 2006. The study was aimed at investigating the impact of different potting media on biomass and growth and also identifying the properties that ...

  3. Unusual “Knob-Like Chimney” Growth Forms on Acropora Species in the Caribbean

    Directory of Open Access Journals (Sweden)

    Andrea Rivera-Sosa

    2018-02-01

    Full Text Available This manuscript provides new insights on an unusual morphological plasticity growth form on Acropora spp. in the Caribbean. This abnormal knob-shaped growth is thought to be a progression from the damselfish “chimneys” that are commonly seen in coral-algal farms. However, the diameters of the observed knobs tend to be much larger on Acropora palmata, where they range from 1.37 to 5.44 cm in diameter, and they tend to be slightly smaller on A. prolifera, where they range from 1.1 to 2.72 cm in diameter. These knob-like chimney growths can affect entire colonies. The knobs are mostly covered with live tissue, while some knobs compete with turf algae. We hypothesize that these growths may be linked to stress from multiple predation and environmental conditions. Local stressors could synergistically influence the regeneration of scarred tissue and skeleton that result from predatory lesions, possibly leading to the formation of the knobs. Therefore, we provide preliminary data from a shallow reef site in coastal Honduras located within the Mesoamerican region where we found the knobs. To the best of our knowledge, the conditions that drive the occurrence of these unusual “knob-like chimneys” on Acropora spp. have not been previously assessed. Thus, we propose a series of guidelines to research the coral morphological plasticity that may be linked to this knob-like chimney phenomenon.

  4. Allelopathic effects of juglone on germination and growth of several herbaceous and woody species

    Science.gov (United States)

    W.J. Rietveld

    1983-01-01

    Laboratory experiments were conducted to determine juglone sensitivity of 16 species (Trifolium incarnatum, Coronilla varia, Vicia villosa, Lespedeza stipulacea, L. cuneata, Acer ginnala, Caragana arboreseens, Elaegnus angustifolia, E. umbellata, Lonieera maackii, Quercus alba, Fraxinus americana, Liriodendron tulipifera, Alnus glutinosa, Pinus strobus...

  5. MT and WY Tamarix soil properties influence germination and early growth of three native grass species

    Science.gov (United States)

    As a riparian invader, Tamarix spp. often leads to native species (e.g., plains cottonwood and willows, grasses) decline and lower habitat quality. Since Tamarix excretes excess salt and has high salt tolerance, negative soil feedback via high soil salinity may negatively affect native plants. Howev...

  6. Unleached Prosopis litter inhibits germination but leached stimulates seedling growth of dry woodland species

    NARCIS (Netherlands)

    Muturi, Gabriel M.; Poorter, Lourens; Bala, Pauline; Mohren, Godefridus M.J.

    2017-01-01

    Prosopis chilensis-Prosopis juliflora hybrid (hereinafter referred to as Prosopis species) invade riverine Acacia woodlands and replace indigenous Acacia tortilis through mechanism that are not yet well understood. Therefore, we tested the hypothesis that dense shade and allelopathic effects of

  7. Alteration in Lignin Biosynthesis Restricts Growth of Fusarium Species in Brown Midrib Sorghum

    Science.gov (United States)

    To improve sorghum for bioenergy and forage uses, brown midrib6 (bmr6) and bmr12 near-isogenic genotypes were developed in different sorghum backgrounds. bmr6 and bmr12 grain had significantly reduced colonization by members of the Gibberella fujikuroi species complex, compared with wild-type, as de...

  8. The influence of aspect on the early growth dynamics of hydroseeded species in coal reclamation areas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Alday, J.; Marrs, R.H.; Martinez-Ruiz, C. [University of Valladolid, Palencia (Spain)

    2008-08-15

    Question: Does aspect affect hydroseeding success and the development of vegetation during early vegetation establishment on the steep slopes of coal wastes during the reclamation process? Location: Open-pit coal mine near Villanueva de la Pena, northern Spain. Methods: In the first year after hydroseeding, we monitored the dynamics of hydroseeded species in three permanent plots of 20 m{sup 2} on north- and south-facing slopes every two months. Soil properties and weather conditions were also monitored. Aspect was related to total plant cover during early revegetation, and south-facing slopes had the lowest cover. Aspect also influenced the early dynamics of hydroseeded grasses and legumes establishing on these slopes. Grass cover was greater on the north slope throughout the study, but differences in plant cover between north and south slopes appeared later for the legumes. Aspect also affected the relative contribution of both of grasses and legumes to the total plant cover, with grasses dominant on both northern and southern slopes, except during the summer on the southern slope. The species with the greatest difference in cover between the north- and south-facing slopes were Festuca spp., Lolium perenne and Trifolium repens. In coal mine reclamation areas of Mediterranean climates, differences in the development of hydroseeded species depended on the slope of the coal mine reclamation areas, and this information is of importance to managers in selecting species for use in reclamation.

  9. The effect of temperature on growth and competition between Sphagnum species

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Heijmans, M.M.P.D.; Robroek, B.J.M.; Berendse, F.

    2008-01-01

    Peat bogs play a large role in the global sequestration of C, and are often dominated by different Sphagnum species. Therefore, it is crucial to understand how Sphagnum vegetation in peat bogs will respond to global warming. We performed a greenhouse experiment to study the effect of four

  10. pCO2 effects on species composition and growth of an estuarine phytoplankton community.

    Science.gov (United States)

    The effects of ongoing changes in ocean carbonate chemistry on plankton ecology have important implications for food webs and biogeochemical cycling. However, conflicting results have emerged regarding species-specific responses to pCO2 enrichment and thus community responses hav...

  11. Evaluation of plant growth regulators to increase nickel phytoextraction by Alyssum species.

    Science.gov (United States)

    Cabello-Conejo, M I; Centofanti, T; Kidd, P S; Prieto-Fernández, A; Chaney, R L

    2013-01-01

    Recent studies have shown that application of phytohormones to shoots of Alyssum murale increased biomass production but did not increase Ni shoot concentration. Increased biomass and Ni phytoextraction efficiency is useful to achieve economically viable phytomining. The objective of this study was to evaluate the effect of two types of phytohormones on the Ni phytoextraction capacity of four Alyssum species. Two different commercially available phytohormones (Cytokin and Promalin) based on cytokinins and/or gibberellins were applied on shoot biomass of four Ni hyperaccumulating Alyssum species (A. corsicum, A. malacitanum, A. murale, and A. pintodasilvae). Cytokin was applied in two concentrations and promalin in one concentration. The application of phytohormones had no clear positive effect on biomass production, Ni accumulation and Ni phytoextraction efficiency in the studied Alyssum species. A. malacitanum was the only species in which a significantly negative effect of these treatments was observed (in Ni uptake). A slightly positive response to promalin treatment was observed in the biomass production and Ni phytoextraction efficiency of A. corsicum. Although this effect was not significant it does indicate a potential application of these approaches to improve phytoextraction ability. Further studies will be needed to identify the most adequate phytohormone treatment as well as the appropriate concentrations and application times.

  12. Old-growth Neotropical forests are shifting in species and trait composition

    NARCIS (Netherlands)

    Sande, van der M.T.; Arets, E.J.M.M.; Pena Claros, M.; Avila, L.A.; Roopsind, A.; Mazzei, L.; Ascarrunz, N.; Finegan, B.; Alarcón, A.; Caceres-Siani, Yasmani; Licona, J.C.; Ruschel, A.R.; Toledo, M.; Poorter, L.

    2016-01-01

    This dataset contains the underlaying data for the study: Tropical forests have long been thought to be in stable state, but recent insights indicate that global change is leading to shifts in forest dynamics and species composition. These shifts may be driven by environmental changes such as

  13. SBDS-deficiency results in deregulation of reactive oxygen species leading to increased cell death and decreased cell growth.

    Science.gov (United States)

    Ambekar, Chhaya; Das, Bikul; Yeger, Herman; Dror, Yigal

    2010-12-01

    Shwachman-Diamond syndrome (SDS) is characterized by reduced hematopoietic and exocrine pancreatic cell numbers and a marked propensity for leukemia. Most patients have mutations in the SBDS gene. We previously reported that SBDS-deficient cells overexpress Fas, undergo accelerated spontaneous and Fas-mediated apoptosis and grow slowly. However the mechanism of how SBDS regulates apoptosis remains unknown. Several studies have shown that reactive oxygen species (ROS) regulate cell growth and spontaneous and Fas-mediated cell death. Therefore, we hypothesized that SBDS-deficiency disrupts ROS regulation and subsequently increases sensitivity to Fas stimulation and reduced cell growth. SBDS was knocked down in HeLa cervical cancer cells and TF-1 myeloid cells using short hairpin RNA. ROS levels were evaluated by oxidation of 2',7'-dichlorodihydrofluorescein diacetate. Apoptosis and cell growth were evaluated with and without antioxidants by annexin V/propidium iodide and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, respectively. We found that shRNA mediated SBDS-knockdown resulted in a significant increase in ROS levels compared to control cells. Fas stimulation further increased ROS levels in the SBDS-knockdown HeLa cells more than in the controls. Importantly, balancing ROS levels by antioxidants rescued SBDS-deficient cells from spontaneous and Fas-mediated apoptosis and reduced cell growth. ROS levels are increased in SBDS-deficient cells, which leads to increased apoptosis and decreased cell growth. Increased baseline and Fas-mediated ROS levels in SBDS-deficient cells can enhance the sensitivity to Fas stimulation. By balancing ROS levels, antioxidants can improve cell growth and survival in SBDS-deficient cells.

  14. Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1) production and Lactobacillus species growth in a defined medium simulating vaginal secretions.

    Science.gov (United States)

    Stingley, Robin L; Liu, Huanli; Mullis, Lisa B; Elkins, Christopher A; Hart, Mark E

    2014-11-01

    Lactobacillus species are commensal with the healthy vaginal environment and inhibit the growth of many pathogenic bacteria in the vaginal tract by a variety of mechanisms, such as the production of hydrogen peroxide, organic acids, and antimicrobial substances. Simulation of the vaginal environment is crucial for proper investigation of the effects of Lactobacillus species on pathogenic bacteria. In this study, we modified a medium used to simulate vaginal secretions to improve the growth of toxic shock syndrome toxin-1 (TSST-1)-producing Staphylococcus aureus clinical strains and Lactobacillus species so that interactions between these bacteria may be examined. A medium consisting of basal salts, vitamins, albumin, glycogen, mucin, urea, sodium bicarbonate, polyoxyethylene sorbitan monolaurate, and amino acids supported the growth of S. aureus and the production of TSST-1 as determined by Western analysis. Improved growth of the Lactobacillus species was seen when this same medium was supplemented with manganese chloride, sodium acetate, and an increase in glucose concentration. However, growth of S. aureus in the supplemented medium resulted in reduced levels of TSST-1. Production of TSST-1 was not detected in a medium routinely used for the growth of Lactobacillus species although S. aureus growth was not inhibited. The development of an improved genital tract secretion medium provides a more authentic environment in which to study the interactions of Lactobacillus species and vaginal pathogens, such as S. aureus. Published by Elsevier B.V.

  15. Growth dynamics of Dracaena cinnabari under controlled conditions as the most effective way to protect endangered species

    Directory of Open Access Journals (Sweden)

    Irena Hubálková

    2017-11-01

    Full Text Available Dracaena cinnabari Balf. fil. is an endangered endemic species growing on the Yemeni island of Soqotra. Dracaena woodlands are considered as one of the oldest forest communities on Earth. Uncontrolled grazing unfortunately caused a lack of naturally occurring regeneration. Our two-year research was focused on the growth dynamics of Dracaena seedlings from two separate populations. One hundred of germinated seeds from two different altitudes from the island were sown and planted under the same conditions. Average increment and difference between the growth dynamics of plants from the two localities were investigated. The observed data on this plant species revealed very interesting, hitherto unknown results. (1 The seedlings germinated within a time period from four to ten weeks. Germination rate was 90% on the Firmihin highland plateau and 78% on the Scand Mountain. (2 Average plant length from both localities was almost the same (24.9 cm at the end of measurement. Differences in values between the two populations proved as non-significant. (3 A significant difference was found in the number of leaves and in the sum of lengths of all leaves on one plant. While the seedlings from Firmihin featured a wide spreading above-ground part with a large number of leaves, the plants from Scand invested more energy into faster leaves elongation rate. (4 Growth dynamics reflected seasonal changes. Increments were slower or ceased during the period of vegetative rest from autumn to spring. (5 Average mortality rate was 13%. Most of the plants died during the period of vegetative rest. Further study on germination and regeneration under artificial conditions seems like the only way to prevent species extinction.

  16. Preliminary data on chronic effects of ultraviolet radiation on the growth of some phytoplankton species of the Beagle Channel, Argentina

    Directory of Open Access Journals (Sweden)

    Marcelo P. Hernando

    1999-12-01

    Full Text Available Serious concerns exist that the thinning of stratospheric ozone and the resulting enhancement in the solar UVB radiation, may impair marine primary productivity. Also, UVB may alter food web dynamics and food availability for higher trophic levels in marine ecosystems inducing changes in phytoplankton species composition. The main goal of this study was to examine the responses of different species of marine phytoplankton to solar UVR. Specifically, we compared the UV sensitivity of a phytoplankton natural community isolated from the Beagle Channel (54°52´S, 68°18´W, Ushuaia, Argentina, as well as the response of two taxa which were isolated from that community (i.e., a pennate diatom, Navicula sp., and a phytoflagellate pertaining to the Class Cryptophyceae to UV radiation. Exposure to UVB or UVA radiation treatments had no significant effects (p > 0.05 on exponential growth rate in Navicula sp. However, when the phytoflagellate [Class Cryptophyceae] was exposed to UVB, the growth rate in the exponential phase was inhibited significantly (p < 0.01 compared with the PAR control. Marked changes in the relative abundance of the main taxonomic groups were observed in the community cultures: the relative abundance of phytoflagellates was significantly lower after exposure to the UVB treatment than after exposure to the PAR treatment (p < 0.05. However, the percentage of centric diatoms increased significantly (p < 0.05 when they were exposed to UVB. The growth rate at the end of the exponential phase of growth of the community was inhibited significantly (p < 0.01 when the algae were exposed to UVB and UVA.

  17. Physiological and genetic differences amongst Rhodococcus species for using glycerol as a source for growth and triacylglycerol production.

    Science.gov (United States)

    Herrero, O Marisa; Moncalián, Gabriel; Alvarez, Héctor M

    2016-02-01

    We analysed the ability of five different rhodococcal species to grow and produce triacylglycerols (TAGs) from glycerol, the main byproduct of biodiesel production. Rhodococcus fascians and Rhodococcus erythropolis grew fast on glycerol, whereas Rhodococcus opacus and Rhodococcus jostii exhibited a prolonged lag phase of several days before growing. Rhodococcus equi only exhibited poor growth on glycerol. R. erythropolis DSMZ 43060 and R. fascians F7 produced 3.9-4.3 g cell biomass l(-1) and 28.4-44.6% cellular dry weight (CDW) of TAGs after 6 days of incubation; whereas R. opacus PD630 and R. jostii RHA1 produced 2.5-3.8 g cell biomass l(-1) and 28.3-38.4% CDW of TAGs after 17 days of growth on glycerol. Genomic analyses revealed two different sets of genes for glycerol uptake and degradation (here named clusters 1 and 2) amongst rhodococci. Those species that possessed cluster 1 (glpFK1D1) (R. fascians and R. erythropolis) exhibited fast growth and lipid accumulation, whereas those that possessed cluster 2 (glpK2D2) (R. opacus, R. jostii and R. equi) exhibited delayed growth and lipid accumulation during cultivation on glycerol. Three glycerol-negative strains were complemented for their ability to grow and produce TAGs by heterologous expression of glpK2 from R. opacus PD630. In addition, we significantly reduced the extension of the lag phase and improved glycerol assimilation and oil production of R. opacus PD630 when expressing glpK1D1 from R. fascians. The results demonstrated that rhodococci are a flexible and amenable biological system for further biotechnological applications based on the reutilization of glycerol.

  18. The good, the bad and the plenty: interactive effects of food quality and quantity on the growth of different Daphnia species.

    Science.gov (United States)

    Bukovinszky, Tibor; Verschoor, Antonie M; Helmsing, Nico R; Bezemer, T Martijn; Bakker, Elisabeth S; Vos, Matthijs; de Senerpont Domis, Lisette N

    2012-01-01

    Effects of food quality and quantity on consumers are neither independent nor interchangeable. Although consumer growth and reproduction show strong variation in relation to both food quality and quantity, the effects of food quality or food quantity have usually been studied in isolation. In two experiments, we studied the growth and reproduction in three filter-feeding freshwater zooplankton species, i.e. Daphnia galeata x hyalina, D. pulicaria and D. magna, on their algal food (Scenedesmus obliquus), varying in carbon to phosphorus (C∶P) ratios and quantities (concentrations). In the first experiment, we found a strong positive effect of the phosphorus content of food on growth of Daphnia, both in their early and late juvenile development. Variation in the relationship between the P-content of animals and their growth rate reflected interspecific differences in nutrient requirements. Although growth rates typically decreased as development neared maturation, this did not affect these species-specific couplings between growth rate and Daphnia P-content. In the second experiment, we examined the effects of food quality on Daphnia growth at different levels of food quantity. With the same decrease in P-content of food, species with higher estimated P-content at zero growth showed a larger increase in threshold food concentrations (i.e. food concentration sufficient to meet metabolic requirements but not growth). These results suggest that physiological processes such as maintenance and growth may in combination explain effects of food quality and quantity on consumers. Our study shows that differences in response to variation in food quality and quantity exist between species. As a consequence, species-specific effects of food quality on consumer growth will also determine how species deal with varying food levels, which has implications for resource-consumer interactions.

  19. Effect of arbuscular mycorrhizal fungi and phosphate fertilization on initial growth of six arboreal species of cerrado

    Directory of Open Access Journals (Sweden)

    Kenia Alves Pereira Lacerda

    2011-09-01

    Full Text Available This study evaluated the benefit of inoculation with arbuscular mycorrhizal fungi, Glomus clarum, for the initial growth of some native arboreal species of the Cerrado biome, namely gabiroba (Campomanesia cambessedeana, baru (Dipterix alata, jatobá (Hymenaea courbaril, ingá (Inga laurina, caroba (Jacaranda cuspidifolia and chichá (Sterculia striata, in unsterilized soil with low (0.02 mg L‑1 and high (0.2 mg L‑1 concentrations of P in the soil solution. Experiments were conducted in a greenhouse, using 1.5 kg vases, for up to 120 days. The experimental design for each arboreal species was completely randomized, with ten replicates in a 2x2 factorial design (inoculated and noninoculated seedlings, and two levels of phosphorus (P in the soil solution. Arboreal plants of the Cerrado biome showed increased mycorrhizal colonization from inoculation with Glomus clarum, except chichá, as this species showed a high indigenous colonization, not differing from the colonization promoted by inoculated fungi. Inoculation promoted increased growth in baru, gabiroba, ingá, caroba and chichá, increasing shoot dry matter (MSPA and root dry matter (MSR. In caroba, this effect was synergistic with application of P to the soil. Baru and jatobá showed increased dry matter with application of P to the soil only. The mycotrophy (mycorrhizal dependence of species and their response to inoculation and to phosphorus are discussed. In order to produce quality seedlings of caroba, gabiroba, chichá and ingá, combining inoculation with Glomus clarum and phosphate fertilization of the soil is recommended, while for jatobá and baru only the application of P to the soil is recommended.

  20. Effect of nocardia rubra species as stimulant drugs on growth of bacteria

    Directory of Open Access Journals (Sweden)

    Алия Агасаф кызы Агаева

    2015-09-01

    Full Text Available The article presents the results of the study about stimulating properties of Nocardia rubra. It is found that the microorganism on Sabouraud agar medium allocates water-soluble red pigment. It easily extracted from the nutrient agar. It is completely harmless and has a strong stimulating effect on the growth of bacteria, particularly gram negative. As the dye it can be used in the food industry

  1. Growth, life history, and species interactions of bluegill sunfish (Lepomis macrochirus) under heavy predation

    Energy Technology Data Exchange (ETDEWEB)

    Belk, Mark Carl [Univ. of Georgia, Athens, GA (United States)

    1992-01-01

    The purpose of this study was, first, to compare growth and life history characteristics of an unfished population of bluegill sunfish (Lepomis macrochirus) in the presence of an abundant predator population to characteristic exhibited by bluegills in typical southeastern US reservoirs where the abundance of predators is reduced, but fishing is increased. The second objective was to determine if differences observed between populations were determined genetically or environmentally.

  2. Height growth to age 8 of larch species and hybrids in Wisconsin.

    Science.gov (United States)

    Don E. Riemenschneider; Hans Nienstaedt

    1983-01-01

    Height growth of tamarack; Siberian, European and Japanese larch; and hybrids between the European and Japanese larch were compared in an 8-year-old test in north-central Wisconsin. Hybrids were tallest and best reached 469 cm (15.4 feet) in mean height at age 8 years from seed. Hybrids exceeded European larch mean height by 12% and tamarack by 23%. Breeding...

  3. Effects of salinity, light and temperature on growth rates of two species of Gracilaria (Rhodophyta)

    Science.gov (United States)

    Xu, Yongjian; Wei, Wei; Fang, Jianguang

    2009-05-01

    Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32°C, 30 and 240 μmol/(m2·s) for G. lichenoides, and 24°C, 20 and 200 μmol/(m2·s) for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates (% increase in wet weight) are determined to be 31.30°C, 32.10, and 287.23 μmol/(m2·s) for G. lichenoides (16.26%/d), and 25.38°C, 21.10, and 229.07 μmol/(m2·s) for G. tenuistipitata (14.83%/d), respectively.

  4. The expression of glycerol facilitators from various yeast species improves growth on glycerol ofSaccharomyces cerevisiae.

    Science.gov (United States)

    Klein, Mathias; Islam, Zia-Ul; Knudsen, Peter Boldsen; Carrillo, Martina; Swinnen, Steve; Workman, Mhairi; Nevoigt, Elke

    2016-12-01

    Glycerol is an abundant by-product during biodiesel production and additionally has several assets compared to sugars when used as a carbon source for growing microorganisms in the context of biotechnological applications. However, most strains of the platform production organism Saccharomyces cerevisiae grow poorly in synthetic glycerol medium. It has been hypothesized that the uptake of glycerol could be a major bottleneck for the utilization of glycerol in S. cerevisiae . This species exclusively relies on an active transport system for glycerol uptake. This work demonstrates that the expression of predicted glycerol facilitators (Fps1 homologues) from superior glycerol-utilizing yeast species such as Pachysolen tannophilus , Komagataella pastoris , Yarrowia lipolytica and Cyberlindnera jadinii significantly improves the growth performance on glycerol of the previously selected glycerol-consuming S. cerevisiae wild-type strain (CBS 6412-13A). The maximum specific growth rate increased from 0.13 up to 0.18 h -1 and a biomass yield coefficient of 0.56 g DW /g glycerol was observed. These results pave the way for exploiting the assets of glycerol in the production of fuels, chemicals and pharmaceuticals based on baker's yeast.

  5. Selectivity of the plant growth regulators trinexapac-ethyl and sulfometuron-methyl to cultivated species

    Directory of Open Access Journals (Sweden)

    Núbia Maria Correia

    2012-06-01

    Full Text Available The aerial spraying of plant ripeners on sugar cane (Saccharum officinarum L. crops causes often the contamination of neighboring areas, which subsidizes formal complaints from the neighbors. These contaminations are due to spraying taking place during inadequate environmental conditions or from technical mistakes during the application. One of the most important causes of this contamination is the susceptibility of the species being cultivated surrounding sugar cane. In order to evaluate the effects of sugar cane plant ripeners trinexapac-ethyl and sulfometuron-methyl on peanuts, cotton, potato, coffee, citrus, beans, sunflower, cassava, rubber, soybean, and grapes, eleven experiments - one for each species - were carried out from May 2009 to Jan. 2010. The field experiment was set according to a completely random design with five treatments and four replications. Just before or during flowering, a single treatment of trinexapac-ethyl at 100 or 200 g ha-1 and sulfometuron-methyl at 7.5 or 15 g ha-1 was applied to plants. A control treatment (plants not treated for each species was part of each experiment. Trinexapac, at the doses of 100 and 200 g ha-1, showed selectivity to peanuts, cotton, potato, coffee, citrus, sunflower, cassava, rubber, soybean, and grape. At the lowest dose (100 g ha-1, it was selective for bean. Sulfometuron, at the dose of 7.5 g ha-1, was selective for peanuts and, at the two studied doses (7.5 and 15 g ha-1, it was selective for coffee, citrus, cassava, and rubber.

  6. Protecting rare, old-growth, forest-associated species under the Survey and Manage program guidelines of the northwest forest plan.

    Science.gov (United States)

    Randy Molina; Bruce G. Marcot; Robin. Lesher

    2006-01-01

    The Survey and Manage Program of the Northwest Forest Plan (MFP) represents an unparalleled attempt to protect rare, little-known species associated with late-successional and old-growth forests on more than 7.7 million ha of federal lands. Approximately 400 species of amphibians, bryophytes, fungi, lichens, mollusks, vascular plants, arthropod functional groups, and...

  7. [Spatial distribution pattern and allometric growth of three common species on moving sand dunes in Horqin Sandy Land, China].

    Science.gov (United States)

    Jia, Mei-yu; Li, Xue-hua; Oh, Choong-hyeon; Park, Hong-chul; Miao, Chun-ping; Han, Xu

    2015-10-01

    Research on fine scale pattern and characteristics of allometric growth could contribute to better understanding plants' adaptation in moving sandy dunes. The abundance, height and biomass of 3 species Agriophilum aquarrosum, Corispermum candelabrum and Setaria viridis in twenty-eight 1 m x 1 m quadrats of Horqin Sandy Land were identified, mapped and described. The nearest neighbor method and O-ring O(r) function analysis were applied to analyze the spatial patterns. The results showed that the individual spatial pattern was mainly aggregated in 1 m x 1 m quadrat at community level but mainly random at population level. At 0-50 cm individual distance scale, both intraspecific and interspecific relationship were facilitation and aggregated distribution occurred at some scales and varied with increasing plant abundance in 1 m x 1 m quadrat. In 0-40 cm, the aggregated distribution of S. viridis and A. aquarrosum increased obviously; in 10-20 cm, both intraspecific and interspecific aggregation increased; in 10-30 cm, the occurrence possibility of positive correlations between S. viridis and A. aquarrosum, S. viridis and C. candelabrum all increased; in 40-50 cm, the possibility of positive correlations between A. squarrosum and S. viridis, A. squarrosum and C. candelabrum all increased. Research on the three species components indicated that the growth rate of above-ground was faster than that of underground. S. viridis had the highest ratio of under-ground biomass to above-ground biomass but its nutritional organs' biomass ratio was medium. C. candelabrum allocated more biomass to propagative organs and stem, but A. squarrosum allocated more biomass to nutritional organs. Based on the spatial distribution and allometric characteristics, the three common species in moving sand dunes preferred r strategy in their life history.

  8. Growth parameters for Lates niloticus (L.), Bagrus docmak (Forsskal), Oreochromis niloticus (L.), Clarias gariepinus (Burchell) and Synodontis species derived from tag returns

    OpenAIRE

    Asila, A.A.; Okemwa, E.

    1999-01-01

    In a tagging experiment carried out in the Kenyan waters of Lake Victoria, an annual growth increment of 29 cm yr was obtained for Lates niloticus (L.). Growth parameters obtained using the von Bertalanffy model on the growth curve fitted by eye were L (inf.) = 122 cm yr and k = 0.26 yr. Data for other species tagged were inadequate to obtain meaningful results.

  9. Impact of trace metal concentrations on coccolithophore growth and morphology: species-specific responses in past and present ocean

    Science.gov (United States)

    Faucher, Giulia; Hoffmann, Linn; Bach, Lennart Thomas; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

    2017-04-01

    The Cretaceous witnessed intervals of profound perturbation named "Oceanic Anoxic Events (OAEs)" characterized by volcanic injection of large amounts of CO2, ocean anoxia, eutrophication, and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a number of nannofossil species. To detect the cause/s of such changes in the fossil record is challenging. Evidence of a correspondence between intervals of high trace metals concentrations and nannofossil dwarfism may be suggestive for a negative effect of these elements on nannoplankton biocalcification process. In order to verify the hypothesis that anomalously high quantities of essential and/or toxic metals were the cause of coccolith dwarfism, we explored the toxicities of a mixture of trace metals on four living coccolithophores species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The trace metals tested were chosen based upon concentration peaks identified in the geological record and upon known trace metal interaction with living coccolithophores algae. Our results demonstrate a species-specific response to trace metal enrichment in living coccolithophores: E. huxleyi, G. oceanica and C. pelagicus showed a decrease in their growth rate with progressively and exponentially increased trace metal concentrations, while P. carterae is unresponsive to trace metal content. Furthermore, E. huxleyi, G. oceanica and C. pelagicus evidenced a decrease in the cell diameter. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccolith of G. oceanica showed a decrease in size only at the highest trace metal concentrations tested. P. carterae size was unresponsive for changing trace metal concentration. Our results on living coccolithophore algae, demonstrate that elevated trace metal concentrations not only affect growth but also coccolith size and/or weight and that

  10. Temperature acclimation of growth, photosynthesis and respiration in two mesophilic phytoplankton species

    DEFF Research Database (Denmark)

    Stæhr, P. A.; Birkeland, M. J.

    2006-01-01

    . aeruginosa showed the same overall pattern of metabolic acclimation to increasing temperatures: (1) overall higher GP and NP but lower R; (2) increasing optimum temperatures for GP, NP and R and (3) higher metabolic rates at supraoptimal temperatures. Microcystis aeruginosa showed several warm-loving traits....... It was more sensitive to increasing temperatures (higher Q10 values), had higher metabolic rates and optimum temperatures and performed better at high incubation temperatures than S. acutus did. This study shows that phytoplankton have a considerable and rapid ability to adjust cellular physiology, metabolism......Temperature acclimation in two mesophilic microalgae, Microcystis aeruginosa (Cyanobacteriales) and Scenedesmus acutus (Chlorococcales), was studied by measuring growth rate, photosynthesis, respiration, cell size, cellular pigment content and Chl a-specific light absorption. Phytoplankton were...

  11. Fuel oil effect on the population growth, species diversity and chlorophyll (a) content of freshwater microalgae.

    Science.gov (United States)

    El-Dib, M A; Abou-Waly, H F; El-Naby, A H

    2001-06-01

    Fresh water algae were subjected to different concentrations (0.03, 0.07, 0.12, 0.25 and 0.5 g x l(-1)) of aqueous extract of reference fuel oil (EPA, USA, API Oil No. 2, 38% aromatic, 1274). Significant decrease in Chlorophyll. (a) was observed as the concentration of fuel oil was increased. The EC50 value of fuel oil after 7 days was 0.29 g x l(-1). Total algal counts and growth rate decreased in response to the studied fuel oil. High diversity values in diatoms were observed in all treated aqueous cultures. High concentrations of fuel oil significantly decreased carbohydrate and protein contents of algal cells.

  12. Growth kinetics and morphology of a ballistic deposition model that incorporates surface diffusion for two species

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Cerdeira, H.A.

    1998-08-01

    We introduce a ballistic deposition model for two kinds of particles (active and inactive) in (2+1) dimensions upon introducing the surface diffusion for the inactive particles. A morphological structural transition is found as the probability of being the inactive particle increases. This transition is well defined by the change in the behavior of the surface width when it is plotted versus time and probability. The exponents α and β calculated for different values of probability show the same behavior. The presence of both types of particles issues three different processes that control the growing surface: overhanging, nonlocal growth and diffusion. It finally leads to a morphological structural transition where the universality changes away from that of Kardar-Parisi-Zhang, in (2+1) dimensions, but not into Edwards-Wilkinson's. (author)

  13. Essential oil of Artemisia scoparia inhibits plant growth by generating reactive oxygen species and causing oxidative damage.

    Science.gov (United States)

    Singh, Harminder Pal; Kaur, Shalinder; Mittal, Sunil; Batish, Daizy Rani; Kohli, Ravinder Kumar

    2009-02-01

    We investigated the chemical composition and phytotoxicity of the essential oil extracted from leaves of Artemisia scoparia Waldst. et Kit. (red stem wormwood, Asteraceae). GC/GC-MS analyses revealed 33 chemical constituents representing 99.83% of the oil. The oil, in general, was rich in monoterpenes that constitute 71.6%, with beta-myrcene (29.27%) as the major constituent followed by (+)-limonene (13.3%), (Z)-beta-ocimene (13.37%), and gamma-terpinene (9.51%). The oil and beta-myrcene were evaluated in a dose-response bioassay under laboratory conditions for phytotoxicity against three weeds-Avena fatua, Cyperus rotundus, and Phalaris minor. A significant reduction in germination, seedling growth, and dry matter accumulation was observed in the test weeds. At the lowest treatment of 0.07 mg/ml Artemisia oil, germination was reduced by 39%, 19%, and 10.6% in C. rotundus, P. minor, and A. fatua, respectively. However, the inhibitory effect of beta-myrcene was less. In general, a dose-dependent effect was observed and the growth declined with increasing concentration. Among the three weeds, the inhibitory effect was greatest on C. rotundus, so it was selected for further studies. We explored the explanation for observed growth inhibition in terms of reactive oxygen species (ROS: lipid peroxidation, membrane integrity, and amounts of conjugated dienes and hydrogen peroxide)-induced oxidative stress. Exposure of C. rotundus to Artemisia oil or beta-myrcene enhanced solute leakage, indicating membrane disintegration. There were increased levels of malondialdehyde and hydrogen peroxide, indicating lipid peroxidation and induction of oxidative stress. We conclude that Artemisia oil inhibits plant root growth through generation of ROS-induced oxidative damage.

  14. Comparison between two meshless methods based on collocation technique for the numerical solution of four-species tumor growth model

    Science.gov (United States)

    Dehghan, Mehdi; Mohammadi, Vahid

    2017-03-01

    As is said in [27], the tumor-growth model is the incorporation of nutrient within the mixture as opposed to being modeled with an auxiliary reaction-diffusion equation. The formulation involves systems of highly nonlinear partial differential equations of surface effects through diffuse-interface models [27]. Simulations of this practical model using numerical methods can be applied for evaluating it. The present paper investigates the solution of the tumor growth model with meshless techniques. Meshless methods are applied based on the collocation technique which employ multiquadrics (MQ) radial basis function (RBFs) and generalized moving least squares (GMLS) procedures. The main advantages of these choices come back to the natural behavior of meshless approaches. As well as, a method based on meshless approach can be applied easily for finding the solution of partial differential equations in high-dimension using any distributions of points on regular and irregular domains. The present paper involves a time-dependent system of partial differential equations that describes four-species tumor growth model. To overcome the time variable, two procedures will be used. One of them is a semi-implicit finite difference method based on Crank-Nicolson scheme and another one is based on explicit Runge-Kutta time integration. The first case gives a linear system of algebraic equations which will be solved at each time-step. The second case will be efficient but conditionally stable. The obtained numerical results are reported to confirm the ability of these techniques for solving the two and three-dimensional tumor-growth equations.

  15. Factors responsible for co-dominance of two beech species in a cool temperate forest in central Japan: interspecific comparison of spatial distribution and growth traits

    Directory of Open Access Journals (Sweden)

    Wataru Ishizuka

    2012-06-01

    Full Text Available To understand the co-existence mechanisms of related species, the recruitment processes of Fagus crenata and F. japonica were censused during 3 and 4 years from emergence, respectively, in a cool-temperate forest in Japan. The distributional properties and the growth traits were compared between two Fagus species. To evaluate the distributional properties, the spatial abundance of seedlings was estimated by a generalized linear model (GLM, with explanatory variables such as topographic variables, light conditions, the presence of dwarf bamboo, and the abundance of the overstory. To evaluate the growth traits under herbivory pressure, both the elongated shoot length and the proportion of recovery from predation (re-growth were also compared. No spatial segregation and no species-specific differences were detected by GLM, which was consistent throughout the census period. Only F. japonica exhibited a slope-related distribution, while F. crenata exhibited no topographical dependence, indicates the distributional overlaps. For the growth traits, contrasting trends were detected, F. crenata was superior in shoot growth, whereas the proportion of re-growth was higher in F. japonica than F. crenata. We concluded that co-dominance of these species was not attributed to the spatial segregation but to the trade-off between growth and resistance to herbivory.

  16. Primary culture and growth characteristics of four different species of lens epithelial cells

    Directory of Open Access Journals (Sweden)

    Li-Xia Ji

    2015-07-01

    Full Text Available AIM: To explore the primary culture conditions for four kinds of lens epithelial cells(LECsof rat, rabbit, dog, and human, and measure their growth characteristics. METHODS: The lens capsule or anterior capsular tissue of rat, rabbit, dog and patient were removed by different methods, and they were cut into tiny pieces for primary culture by modified tissue adherent method. The morphological features of four kinds of LECs were observed under an inverted microscope.RESULTS: Four kinds of LECs of rat, rabbit, dog and human could be cultured primarily by tissue adherent method. With the evolution of tissue source, the adherent capacity of LECs gradually strengthened, cells form were changed from irregular polygon to oval, nucleus rounded and cytoplasm enriched gradually. Four kinds of LECs had fibrotic changes after several passages.CONCLUSION: LECs of rat, rabbit, dog and human can be primarily cultured. This method lays the foundation for the mechanism research of caratact and related fields on the cellular and molecular levels.

  17. Burkholderia species associated with legumes of Chiapas, Mexico, exhibit stress tolerance and growth in aromatic compounds.

    Science.gov (United States)

    de León-Martínez, José A; Yañez-Ocampo, Gustavo; Wong-Villarreal, Arnoldo

    Leguminous plants have received special interest for the diversity of β-proteobacteria in their nodules and are promising candidates for biotechnological applications. In this study, 15 bacterial strains were isolated from the nodules of the following legumes: Indigofera thibaudiana, Mimosa diplotricha, Mimosa albida, Mimosa pigra, and Mimosa pudica, collected in 9 areas of Chiapas, Mexico. The strains were grouped into four profiles of genomic fingerprints through BOX-PCR and identified based on their morphology, API 20NE biochemical tests, sequencing of the 16S rRNA, nifH and nodC genes as bacteria of the Burkholderia genus, genetically related to Burkholderia phenoliruptrix, Burkholderia phymatum, Burkholderia sabiae, and Burkholderia tuberum. The Burkholderia strains were grown under stress conditions with 4% NaCl, 45°C, and benzene presence at 0.1% as the sole carbon source. This is the first report on the isolation of these nodulating species of the Burkholderia genus in legumes in Mexico. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Species- to continental-scale influences of nitrogen and sulfur deposition on tree growth and mortality across the conterminous United States

    Science.gov (United States)

    Horn, K. J.; Thomas, R. Q.; Pardo, L. H.; Clark, C.; Fenn, M. E.; Lawrence, G. B.; Perakis, S.; Smithwick, E. A. H.; Baldwin, D. C.; Braun, S.; Nordin, A.; Perry, C. H.; Phelan, J.; Schaberg, P. G.; St Clair, S. B.; Warby, R.; Watmough, S. A.

    2017-12-01

    Anthropogenic nitrogen (N) deposition influences the global land carbon (C) sink in part through increasing C uptake in trees. However, the influence of atmospheric N deposition is not uniform across tree species and environments. Additionally, sulfur (S) deposition frequently covaries with N deposition and contributes to soil acidification, which confounds the ability to attribute tree responses to N or S deposition. In an attempt to understand how atmospheric N and S deposition affect the growth and survival of individual tree species and whole forests, we analyzed growth and survival data of over one million trees between 2000 and 2016 for the conterminous United States across environmental gradients of temperature, precipitation, and N and S deposition. Of the 94 tree species assessed, 89 showed responses in growth and/or survival that varied with N or S deposition. The net rate of increase in C uptake across all surveyed trees was 17 Δkg C/Δkg N when S deposition was considered in the species models, but was lower at 9.9 Δkg C/Δkg N when S deposition was not considered. Tree survival rates had a net negative response to N deposition at rates of -0.0648 and -0.441 Δ%P(s)/Δkg N ha-1yr-1 (change in the % probability of survival), with and without S deposition considered respectively. However, individual species responses varied greatly, and growth and survival responses often differed for the same species. For growth, 30 tree species increased with N deposition, 6 decreased, and 19 had unimodal response curves while 39 showed no relationship. For survival, 5 increased, 6 decreased, and 26 had unimodal response curves while 57 did not change across N deposition gradients. Regional responses to N deposition varied greatly with forest compositions; however, both positively and negatively responding species were often present in the same stand. This indicates that the influence of N deposition on tree C uptake is in part determined by species composition and

  19. Growth kinetic models of five species of Lactobacilli and lactose consumption in batch submerged culture

    Directory of Open Access Journals (Sweden)

    Fazlollah Rezvani

    Full Text Available Abstract Kinetic behaviors of five Lactobacillus strains were investigated with Contois and Exponential models. Awareness of kinetic behavior of microorganisms is essential for their industrial process design and scale up. The consistency of experimental data was evaluated using Excel software. L. bulgaricus was introduced as the most efficient strain with the highest biomass and lactic acid yield of 0.119 and 0.602 g g-1 consumed lactose, respectively. The biomass and carbohydrate yield of L. fermentum and L. lactis were slightly less and close to L. bulgaricus. Biomass and lactic acid production yield of 0.117 and 0.358 for L. fermentum and 0.114 and 0.437 g g-1 for L.actobacillus lactis were obtained. L. casei and L. delbrueckii had the less biomass yield, nearly 11.8 and 22.7% less than L. bulgaricus, respectively. L. bulgaricus (R 2 = 0.9500 and 0.9156 and L. casei (R 2 = 0.9552 and 0.8401 showed acceptable consistency with both models. The investigation revealed that the above mentioned models are not suitable to describe the kinetic behavior of L. fermentum (R 2 = 0.9367 and 0.6991, L. delbrueckii (R 2 = 0.9493 and 0.7724 and L. lactis (R 2 = 0.8730 and 0.6451. Contois rate equation is a suitable model to describe the kinetic of Lactobacilli. Specific cell growth rate for L. bulgaricus, L. casei, L. fermentum, L. delbrueckii and L. lactis with Contois model in order 3.2, 3.9, 67.6, 10.4 and 9.8-fold of Exponential model.

  20. Growth kinetic models of five species of Lactobacilli and lactose consumption in batch submerged culture.

    Science.gov (United States)

    Rezvani, Fazlollah; Ardestani, Fatemeh; Najafpour, Ghasem

    Kinetic behaviors of five Lactobacillus strains were investigated with Contois and Exponential models. Awareness of kinetic behavior of microorganisms is essential for their industrial process design and scale up. The consistency of experimental data was evaluated using Excel software. L. bulgaricus was introduced as the most efficient strain with the highest biomass and lactic acid yield of 0.119 and 0.602gg -1 consumed lactose, respectively. The biomass and carbohydrate yield of L. fermentum and L. lactis were slightly less and close to L. bulgaricus. Biomass and lactic acid production yield of 0.117 and 0.358 for L. fermentum and 0.114 and 0.437gg -1 for L.actobacillus lactis were obtained. L. casei and L. delbrueckii had the less biomass yield, nearly 11.8 and 22.7% less than L. bulgaricus, respectively. L. bulgaricus (R 2 =0.9500 and 0.9156) and L. casei (R 2 =0.9552 and 0.8401) showed acceptable consistency with both models. The investigation revealed that the above mentioned models are not suitable to describe the kinetic behavior of L. fermentum (R 2 =0.9367 and 0.6991), L. delbrueckii (R 2 =0.9493 and 0.7724) and L. lactis (R 2 =0.8730 and 0.6451). Contois rate equation is a suitable model to describe the kinetic of Lactobacilli. Specific cell growth rate for L. bulgaricus, L. casei, L. fermentum, L. delbrueckii and L. lactis with Contois model in order 3.2, 3.9, 67.6, 10.4 and 9.8-fold of Exponential model. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  1. Growth inhibition and antioxidative response of wood decay fungi exposed to plant extracts of Casearia species.

    Science.gov (United States)

    Bento, T S; Torres, L M B; Fialho, M B; Bononi, V L R

    2014-01-01

    Ligninolytic fungi take part in critical processes in ecosystems such as nutrient recycling; however, some fungal species can be pathogenic to forest and urban trees and deteriorate wood products. The tropical flora is an important source of antimicrobial compounds environmentally safer than traditional wood preservatives. Therefore, this study aimed to evaluate the inhibitory activity of ethanol plant extracts of Casearia sylvestris and Casearia decandra on the white-rot wood decay basidiomycetes Trametes villosa and Pycnoporus sanguineus. In addition, the effect of the extracts on the fungal antioxidative metabolism was studied. Among the different substances present in the extracts, the phytochemical analyses identified a clerodane diterpenoid (C. sylvestris) and cinnamic acid, hydroquinone and β-sitosterol (C. decandra). The extracts inhibited the fungi up to 70% and caused hyphal morphology changes. The extracts triggered oxidative stress process as indicated by the increased levels of the antioxidant enzymes catalase and glutathione reductase. Therefore, the Casearia extracts are a potential source of natural biocides to control wood decay fungi, and one of the mechanisms of action is the oxidative stress. The Casearia plant extracts exhibited important antifungal activity on wood decay fungi and triggered oxidative stress process, an inhibitory mechanism rarely studied in filamentous fungi exposed to plant extracts. Therefore, a starting point was provided for the development of natural compounds-based products as an alternative to chemical fungicides. In addition, subsidies were given to further studies in order to elucidate in more detail how compounds present in extracts of native tropical plants affect the physiology of fungi. © 2013 The Society for Applied Microbiology.

  2. Impacts of simulated climate change and fungal symbionts on survival and growth of a foundation species in sand dunes.

    Science.gov (United States)

    Emery, Sarah M; Rudgers, Jennifer A

    2013-12-01

    For many ecosystems, one of the primary avenues of climate impact may be through changes to foundation species, which create habitats and sustain ecosystem services. For plants, microbial symbionts can often act as mutualists under abiotic stress and may mediate foundational plant responses to climate change. We manipulated the presence of endophytes in Ammophila breviligulata, a foundational sand dune species, to evaluate their potential to influence plant responses to climate change. We simulated projected climate change scenarios for temperature and precipitation using a growth chamber experiment. A 5 °C increase in temperature relative to current climate in northern Michigan reduced A. breviligulata survival by 45 %. Root biomass of A. breviligulata, which is critical to dune stabilization, was also strongly reduced by temperature. Plants inoculated with the endophyte had 14 % higher survival than endophyte-free plants. Contrary to our prediction, endophyte symbiosis did not alter the magnitude or direction of the effects of climate manipulations on A. breviligulata survival. However, in the absence of the endophyte, an increase in temperature increased the number of sand grains bound by roots by 80 %, while in symbiotic plants sand adherence did not significantly respond to temperature. Thus, plant-endophyte symbiosis actually negated the benefits in ecosystem function gained under a warmer climate. This study suggests that heat stress related to climate change in the Great Lakes may compromise the ability of A. breviligulata to stabilize dune ecosystems and reduce carbon storage and organic matter build-up in these early-successional systems due to reduced plant survival and root growth.

  3. The role of growth form and correlated traits in competitive ranking of six perennial ruderal plant species grown in unbalanced mixtures

    Science.gov (United States)

    Dietz, Hansjörg; Steinlein, Thomas; Ullmann, Isolde

    1998-02-01

    The competitive abilities of six perennial ruderal plants of three different growth forms were compared via yield measures using an additive diallel experimental design with unbalanced mixtures (9:3 or 3:9 plants per pot, respectively). Thus, in a given mixture species A was grown in two configurations: three individuals in centre position of the pot together with nine plants of species B in border position and vice versa. Effect competitive abilities as well as response competitive abilities of the species were significantly related to canopy height and plant biomass. The species with lower rosette growth form and smaller biomasses were weaker competitors than the species possessing elevated canopies along with higher biomasses, whereas total leaf area was not significantly correlated with competitive ability between species. Species differences in competitive ability were stronger between the plants grown in the central position than between those grown in the border position. Furthermore, interactions between species-specific traits and configuration could be observed, indicating the importance of species proportions and arrangement patterns for evaluation of competitive outcome in the field. The degree of complete transitivity of the competitive network of the six ruderal species, which was significantly higher than expected under the null model in our experimental design, also seemed to depend on species proportions in mixture. Shifts in root:shoot ratio of the centre plants when faced with competition by the border plants were in the direction of higher shoot allocation for the weak competitors with rosette growth form irrespective of the neighbour species, except for Bunias orientalis, which showed a more plastic response. The stronger competitors showed higher root allocation ( Urtica dioica) or were hardly affected at all. Consistent with the results of our experiment, the weaker competitors occur at rather frequently disturbed and therefore transient

  4. Interaction of plant growth regulators and reactive oxygen species to regulate petal senescence in wallflowers (Erysimum linifolium).

    Science.gov (United States)

    Salleh, Faezah Mohd; Mariotti, Lorenzo; Spadafora, Natasha D; Price, Anna M; Picciarelli, Piero; Wagstaff, Carol; Lombardi, Lara; Rogers, Hilary

    2016-04-02

    transcript abundance of WPS46, an auxin-induced gene. A model for the interaction between cytokinins, ethylene, reactive oxygen species and auxin in the regulation of floral senescence in wallflowers is proposed. The combined increase in ethylene and reduction in cytokinin triggers the initiation of senescence and these two plant growth regulators directly or indirectly result in increased reactive oxygen species levels. A fall in conjugated auxin and/or the total auxin pool eventually triggers abscission.

  5. Assessing the effect of copper on growth, copper accumulation and physiological responses of grazing species Atriplex halimus: ecotoxicological implications.

    Science.gov (United States)

    Mateos-Naranjo, E; Andrades-Moreno, L; Cambrollé, J; Perez-Martin, A

    2013-04-01

    Tolerance of plants to elevated concentrations of heavy metals in growth media and in its tissues leads to high degrees of metal bioaccumulation, which may pose a risk for humans and animals alike. Therefore, bio-accumulating plants need thorough evaluation from an environmental health point of view. A glasshouse experiment concerning the xerohalophyte Atriplex halimus was carried out to determine its tolerance and capacity to accumulate copper. We investigated the effect of Cu from 0 to 30 mmol l(-1) on the growth, photosynthetic apparatus and nutrient uptake of A. halimus by measuring gas exchange, chlorophyll fluorescence and photoinhibition. We also determined total Cu, sodium, potassium, magnesium, phosphorous, and nitrogen content in the plant. Our results indicated that A. halimus presented a high resistance to Cu-induced stress, since the plants were able to survive at concentrations higher than 15 mmol l(-1) Cu. However, this capacity was not reflected in its ability to accumulate and tolerate greater amounts of Cu in its tissues, since clear phytotoxicity symptoms were detected at tissue concentrations greater than 38 mg kg(-1) Cu. Thus, Cu increment caused a reduction in A. halimus growth, which was related to a decrease in net photosynthetic rate. This reduction was associated with the adverse effect of Cu on the photochemical apparatus and the reduction in the absorption of essential nutrients. The high resistance of A. halimus was largely related with the capacity of this species to avoid the absorption of great amounts of Cu. For all the above reasons, A. halimus could have the characteristics of a Cu-exclusion plant. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Factors responsible for co-dominance of two beech species in a cool temperate forest in central Japan: interspecific comparison of spatial distribution and growth traits

    Directory of Open Access Journals (Sweden)

    Wataru Ishizuka

    2012-05-01

    Full Text Available To understand the co-existence mechanisms of related species,the recruitment processes of Fagus crenata and F. japonica were censused during 3 and 4 years from emergence, respectively, in a cool-temperate forest in Japan. The distributional properties and the growth traits were compared between two Fagus species. To evaluate the distributional properties, the spatial abundance of seedlings was estimated by a generalized linear model (GLM, with explanatory variables such as topographic variables, light conditions, the presence of dwarf bamboo, and the abundance of the overstory. To evaluate the growth traits under herbivory pressure, both the elongated shoot length and the proportion of recovery frompredation (re-growth were also compared. No spatial segregation and no species-specific differences were detected by GLM, which was consistent throughout the census period. Only F. japonica exhibited a slope-related distribution, while F. crenata exhibited no topographical dependence, indicates the distributional overlaps. For the growth traits, contrasting trends were detected, F. crenata was superior in shoot growth, whereas the proportion of regrowth was higher in F. japonica than F. crenata. We concluded that co-dominance of these species was not attributed to the spatial segregationbut to the trade-off between growth and resistance to herbivory.

  7. Effectiveness of native arbuscular mycorrhiza on the growth of four tree forest species from the Santa Marta Mountain, Veracruz (Mexico

    Directory of Open Access Journals (Sweden)

    Yolanda Retama-Ortiz

    2017-05-01

    Full Text Available Aim of the study: The aim of this work was to isolate consortia of arbuscular mycorrhizal fungi (AMF associated to Liquidambar styraciflua in soils of the Santa Marta Mountain in Veracruz, and to select highly effective mycorrhizal consortia on promoting the growth of four tree forest species with economic and ecological importance. Area of study: Santa Marta Mountain, inside the buffer area of the Los Tuxtlas Biological Reserve in Veracruz (México. Materials and methods: Ten composite samples of rhizosphere soil were collected from L. styraciflua trees of 13-15 cm DBH (diameter at breast height. Roots were fixed in FAA solution to determine the mycorrhizal colonization percentage, the abundance of morphospecies, and its effectiveness in promoting the growth of L. styraciflua, Terminalia amazonia, Cordia alliodora, and Cojoba arborea. Soil physical and chemical characteristics were also analysed, and soil type recognition was performed with the Reference Base for Soil FAO-ISRIC World-SICS. Mycorrhizal colonization was determined by the method of clearing and staining roots with trypan blue; total percentage of colonization was estimated by the Linderman-Biermann method. Spores were extracted for counting and identifying morphospecies from each soil sample, those with more effectiveness were selected and inoculated in the four tree species, based upon a completely random design there were evaluated height, number of leaves, total dry weight and foliar area. Main results: Average mycorrhizal colonization percentage was 45% from natural conditions, samples one and four showed 80% of AMF-colonization. Average number of spores was 617 in 100 g-1 of dry soil. Forty-seven AMF-morphospecies were identified. After eight months significant differences were observed in root colonization, height, number of leaves, total dry weight, leaf area and foliar analysis of N5+, P5+ and K+ on plants inoculated with rhizosphere samples of L. styraciflua. Terminalia

  8. Effectiveness of native arbuscular mycorrhiza on the growth of four tree forest species from the Santa Marta Mountain, Veracruz (Mexico)

    International Nuclear Information System (INIS)

    Retama-Ortiz, Y.; Ávila-Bello, C.H.; Alarcón, A.; Ferrera-Cerrato, R.

    2017-01-01

    Aim of the study: The aim of this work was to isolate consortia of arbuscular mycorrhizal fungi (AMF) associated to Liquidambar styraciflua in soils of the Santa Marta Mountain in Veracruz, and to select highly effective mycorrhizal consortia on promoting the growth of four tree forest species with economic and ecological importance. Area of study: Santa Marta Mountain, inside the buffer area of the Los Tuxtlas Biological Reserve in Veracruz (México). Materials and methods: Ten composite samples of rhizosphere soil were collected from L. styraciflua trees of 13-15 cm DBH (diameter at breast height). Roots were fixed in FAA solution to determine the mycorrhizal colonization percentage, the abundance of morphospecies, and its effectiveness in promoting the growth of L. styraciflua, Terminalia amazonia, Cordia alliodora, and Cojoba arborea. Soil physical and chemical characteristics were also analysed, and soil type recognition was performed with the Reference Base for Soil FAO-ISRIC World-SICS. Mycorrhizal colonization was determined by the method of clearing and staining roots with trypan blue; total percentage of colonization was estimated by the Linderman-Biermann method. Spores were extracted for counting and identifying morphospecies from each soil sample, those with more effectiveness were selected and inoculated in the four tree species, based upon a completely random design there were evaluated height, number of leaves, total dry weight and foliar area. Main results: Average mycorrhizal colonization percentage was 45% from natural conditions, samples one and four showed 80% of AMF-colonization. Average number of spores was 617 in 100 g-1 of dry soil. Forty-seven AMF-morphospecies were identified. After eight months significant differences were observed in root colonization, height, number of leaves, total dry weight, leaf area and foliar analysis of N5+, P5+ and K+ on plants inoculated with rhizosphere samples of L. styraciflua. Terminalia amazonia and

  9. Effectiveness of native arbuscular mycorrhiza on the growth of four tree forest species from the Santa Marta Mountain, Veracruz (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Retama-Ortiz, Y.; Ávila-Bello, C.H.; Alarcón, A.; Ferrera-Cerrato, R.

    2017-11-01

    Aim of the study: The aim of this work was to isolate consortia of arbuscular mycorrhizal fungi (AMF) associated to Liquidambar styraciflua in soils of the Santa Marta Mountain in Veracruz, and to select highly effective mycorrhizal consortia on promoting the growth of four tree forest species with economic and ecological importance. Area of study: Santa Marta Mountain, inside the buffer area of the Los Tuxtlas Biological Reserve in Veracruz (México). Materials and methods: Ten composite samples of rhizosphere soil were collected from L. styraciflua trees of 13-15 cm DBH (diameter at breast height). Roots were fixed in FAA solution to determine the mycorrhizal colonization percentage, the abundance of morphospecies, and its effectiveness in promoting the growth of L. styraciflua, Terminalia amazonia, Cordia alliodora, and Cojoba arborea. Soil physical and chemical characteristics were also analysed, and soil type recognition was performed with the Reference Base for Soil FAO-ISRIC World-SICS. Mycorrhizal colonization was determined by the method of clearing and staining roots with trypan blue; total percentage of colonization was estimated by the Linderman-Biermann method. Spores were extracted for counting and identifying morphospecies from each soil sample, those with more effectiveness were selected and inoculated in the four tree species, based upon a completely random design there were evaluated height, number of leaves, total dry weight and foliar area. Main results: Average mycorrhizal colonization percentage was 45% from natural conditions, samples one and four showed 80% of AMF-colonization. Average number of spores was 617 in 100 g-1 of dry soil. Forty-seven AMF-morphospecies were identified. After eight months significant differences were observed in root colonization, height, number of leaves, total dry weight, leaf area and foliar analysis of N5+, P5+ and K+ on plants inoculated with rhizosphere samples of L. styraciflua. Terminalia amazonia and

  10. Phytotoxic Effects of Nepeta meyeri Benth. Extracts and Essential Oil on Seed Germinations and Seedling Growths of Four Weed Species

    Directory of Open Access Journals (Sweden)

    Saban Kordali

    2015-05-01

    Full Text Available Essential oil isolated from the aerial parts of Nepeta meyeri Benth. by hydrodistilation was analysed by GC and GC-MS methods. A total 18 components were identified in the oil representing 100.0% of the oil. Main components were 4aα,7α,7aβ-nepetalactone (80.3%, 4aα,7α,7aα–nepetalactone (10.3%, trans-pulegol (3.1%, 1, 8-cineole (3.0% and β-bourbonene (2.0%. In addition, n-hexane extract of N. meyeri was analysed by using GC and GC-MS methods and 18 components were identified. Likewise, nepetalactones, 4aα,7α,7aβ-nepetalactone (83.7%, 4aα,7α,7aα–nepetalactone (3.6%, 1, 8-cineole (1.9% and α-terpinene (1.5% were the predominat compounds in the hexane extract. Three concentrations (0.5, 1.0 and 2.0 mg/mL of the essential oil and n-hexane, chloroform, acetone and methanol extracts isolated from the aerial partsand roots were tested for the herbicidal effects on the germination of the seeds of four weed species including Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense L. and Sinapsis arvensis L. The essential oil of N. meyeri completely inhibited the germination of all weed seeds whereas the extracts showed various inhibition effects on the germination of the weed species. Herbicidal effect was increased with the increasing application concentrations of the extracts. In general, the acetone extract was found to be more effective as compared to the other extracts. All extracts also exhibited various inhibition effects on the seedling growths of the weed species. All extracts also tested for their phytotoxic effects on the weeds at greenhouse condition and the results showed that the oil and extracts caused mortality with 22.00-66.00% 48h after the treatments. These findings suggest that the essential oil and the extracts of N. meyeri have potentials for use as herbicides against those weed species.

  11. Growth potential of alternative eucalyptus species for mid and high altitude sites in the summer rainfall region in South Africa

    CSIR Research Space (South Africa)

    Komakech Otim, C

    2008-12-01

    Full Text Available between the impact of disease infestation and growth performance. It was found that negative phenotypic correlations existed between the levels of infection and tree growth. ie greater infection slower growth. Evaluation of genotype x environment...

  12. Effect of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi Essential Oils on the Growth and Mycotoxins Production by Aspergillus Species.

    Science.gov (United States)

    Gemeda, Negero; Woldeamanuel, Yimtubezinash; Asrat, Daniel; Debella, Asfaw

    2014-01-01

    This study was performed to investigate effect of essential oils on Aspergillus spore germination, growth, and mycotoxin production. In vitro antifungal and antiaflatoxigenic activities of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi essential oils were carried out on toxigenic strains of Aspergillus species. Plant materials were hydrodistilled for 4-5 h in Clevenger apparatus. 0.25 μL/mL, 0.5 μL/mL, 1 μL/mL, 2 μL/mL, and 4 μL/mL concentrations of each essential oil were prepared in 0.1% Tween 80 (V/V). T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 μL/mL by essential oils of T. ammi. The oil also showed complete inhibition of spore germination at a concentration of 2 μL/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting toxin production from A. niger and A. flavus at 0.5 and 0.75 μL/mL, respectively. C. martinii, F. vulgare, and T. ammi oils as antifungals were found superior over synthetic preservative. Moreover, a concentration of 5336.297 μL/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity. In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by Aspergillus species.

  13. Effect of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi Essential Oils on the Growth and Mycotoxins Production by Aspergillus Species

    Directory of Open Access Journals (Sweden)

    Negero Gemeda

    2014-01-01

    Full Text Available This study was performed to investigate effect of essential oils on Aspergillus spore germination, growth, and mycotoxin production. In vitro antifungal and antiaflatoxigenic activities of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi essential oils were carried out on toxigenic strains of Aspergillus species. Plant materials were hydrodistilled for 4-5 h in Clevenger apparatus. 0.25 μL/mL, 0.5 μL/mL, 1 μL/mL, 2 μL/mL, and 4 μL/mL concentrations of each essential oil were prepared in 0.1% Tween 80 (V/V. T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 μL/mL by essential oils of T. ammi. The oil also showed complete inhibition of spore germination at a concentration of 2 μL/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting toxin production from A. niger and A. flavus at 0.5 and 0.75 μL/mL, respectively. C. martinii, F. vulgare, and T. ammi oils as antifungals were found superior over synthetic preservative. Moreover, a concentration of 5336.297 μL/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity. In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by Aspergillus species.

  14. Resource Limitations Influence Growth and Vigor of Idaho Fescue, a Common Understory Species in Pacific Northwest Ponderosa Pine Forests

    Directory of Open Access Journals (Sweden)

    Craig A. Carr

    2016-12-01

    Full Text Available Alterations in under-canopy resource availability associated with elevated ponderosa pine (Pinus ponderosa Dougl. abundance can negatively influence understory vegetation. Experimental evidence linking under-canopy resource availability and understory vegetation is scarce. Yet this information would be beneficial in developing management strategies to recover desired understory species. We tested the effects of varying nitrogen (N and light availability on Idaho fescue (Festuca idahoensis Elmer, the dominant understory species in ponderosa pine/Idaho fescue plant associations in eastern Oregon. In a greenhouse experiment, two levels of N (50 kg∙N∙ha−1 and 0 kg∙N∙ha−1 and shade (80% shade and 0% shade were applied in a split-plot design to individual potted plants grown in soil collected from high abundance pine stands. Plants grown in unshaded conditions produced greater root (p = 0.0027 and shoot (p = 0.0017 biomass and higher cover values (p = 0.0378 compared to those in the shaded treatments. The addition of N had little effect on plant growth (p = 0.1602, 0.5129, and 0.0853 for shoot biomass, root biomass, and cover, respectively, suggesting that soils in high-density ponderosa pine stands that lack understory vegetation were not N deficient and Idaho fescue plants grown in these soils were not N limited. Management activities that increase under-canopy light availability will promote the conditions necessary for Idaho fescue recovery. However, successful restoration may be constrained by a lack of residual fescue or the invasion of more competitive understory vegetation.

  15. Allelopathic effects of microcystin-LR on the germination, growth and metabolism of five charophyte species and a submerged angiosperm.

    Science.gov (United States)

    Rojo, Carmen; Segura, Matilde; Cortés, Francisco; Rodrigo, María A

    2013-11-15

    Microcystins (MCs) are produced by cyanobacteria in aquatic environments and adversely affect macrophytes at very high concentrations. However, the effects of MC on macrophytes at concentrations of environmental relevance are largely unknown. The main objective of this study was to analyze the allelopathic effects of MC-LR at natural concentrations (1, 8 and 16 μg MC-LR/L) on five charophyte species (Chara aspera, C. baltica, C. hispida, C. vulgaris and Nitella hyalina) and the angiosperm Myriophyllum spicatum. Macrophyte specimens were obtained from a restored area located in Albufera de València Natural Park, a protected coastal Mediterranean wetland. Two different experiments were conducted involving (i) the addition of MC-LR to natural sediment to evaluate its effects on seed germination and (ii) the addition of MC-LR to water cultures of macrophytes to evaluate its effects on growth and metabolic functions. In water, the MC-LR concentration decreased by 84% in two weeks; the loss was not significant in sediment. The first seedlings (all C. hispida) emerged from the wetland sediment following a delay of a few days in the presence of MC-LR. The germination rates in 8 and 16 μg MC-LR/L treatments were 44% and 11% of that occurring in the absence of MC, but these differences disappeared over time. The final density was 6-7 germlings/dm(3). Final germling length was unaffected by MC-LR. Rotifers (Lecane spp.) emerging from the natural sediment during the experiment were favored by MC-LR; the opposite pattern was observed in the cladoceran Daphnia magna. The growth rates of C. vulgaris, C. baltica and N. hyalina were unaffected by MC exposure, whereas those of C. hispida and C. aspera were reduced in the MC treatments relative to the control treatment. The concentration of chlorophyll-a and the in vivo net photosynthetic rate were lower in the presence of MC-LR, even at the lowest concentration, for all of the characeans tested. M. spicatum was sensitive to the

  16. Trophic Relationships between the Parasitic Plant Species Phelipanche ramosa (L.) and Different Hosts Depending on Host Phenological Stage and Host Growth Rate

    Science.gov (United States)

    Moreau, Delphine; Gibot-Leclerc, Stéphanie; Girardin, Annette; Pointurier, Olivia; Reibel, Carole; Strbik, Florence; Fernández-Aparicio, Mónica; Colbach, Nathalie

    2016-01-01

    Phelipanche ramosa (L.) Pomel (branched broomrape) is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host’s expense so that host–parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L.) (oilseed rape) and two weed species, Capsella bursa-pastoris (L.) Medik. and Geranium dissectum (L.). Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34 to 84%). B. napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per host plant

  17. Trophic relationships between the parasitic plant species Phelipanche ramosa (L. and different hosts depending on host phenological stage and host growth rate

    Directory of Open Access Journals (Sweden)

    Delphine Moreau

    2016-07-01

    Full Text Available Phelipanche ramosa (L. Pomel (branched broomrape is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host's expense so that host-parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L. (oilseed rape and two weed species, Capsella bursa-pastoris (L. Medik. and Geranium dissectum (L.. Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34% to 84%. Brassica napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per

  18. Species distribution models and impact factor growth in environmental journals: methodological fashion or the attraction of global change science.

    Directory of Open Access Journals (Sweden)

    Lluís Brotons

    Full Text Available In this work, I evaluate the impact of species distribution models (SDMs on the current status of environmental and ecological journals by asking the question to which degree development of SDMs in the literature is related to recent changes in the impact factors of ecological journals. The hypothesis evaluated states that research fronts are likely to attract research attention and potentially drive citation patterns, with journals concentrating papers related to the research front receiving more attention and benefiting from faster increases in their impact on the ecological literature. My results indicate a positive relationship between the number of SDM related articles published in a journal and its impact factor (IF growth during the period 2000-09. However, the percentage of SDM related papers in a journal was strongly and positively associated with the percentage of papers on climate change and statistical issues. The results support the hypothesis that global change science has been critical in the development of SDMs and that interest in climate change research in particular, rather than the usage of SDM per se, appears as an important factor behind journal IF increases in ecology and environmental sciences. Finally, our results on SDM application in global change science support the view that scientific interest rather than methodological fashion appears to be the major driver of research attraction in the scientific literature.

  19. Dwarf males, large hermaphrodites and females in marine species: a dynamic optimization model of sex allocation and growth.

    Science.gov (United States)

    Yamaguchi, Sachi; Sawada, Kota; Yusa, Yoichi; Iwasa, Yoh

    2013-05-01

    In this study, we investigate the evolutionarily stable schedule of growth and sex allocation for marine benthic species that contain dwarf males. We consider a population in an ephemeral microhabitat that receives a constant supply of larvae. Small individuals can immediately reproduce as a dwarf male or remain immature and grow. Large individuals allocate reproductive resources between male and female functions. The fraction c of newly settled individuals who remain immature and the sex allocation of large individuals m are quantities to evolve. In the stationary ESS, if the relative reproductive success of dwarf males is greater than the survivorship of immature individuals until they reach a mature size, then the population is a mixture of females and dwarf males. If the opposite inequality holds, the population is dominated by hermaphrodites and lacks dwarf males. There is no case in which a mixture of hermaphrodites and dwarf males to be the ESS in the stationary solution. The ESS can be solved by dynamic programming when the strategies depend on the age of the microhabitat (c(t) and m(t)). Typically, the ESS schedule begins with a population composed only of hermaphrodites, which is replaced by a mixture of dwarf males and hermaphrodites and then by a mixture of dwarf males and pure females. The relative importance of these three phases depends on multiple parameters. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Species Specific Responses to Age on Nodule Formation, Seedling Growth, and Biomass Production of Acacia auriculiformis at Nursery Stage

    Directory of Open Access Journals (Sweden)

    Md. Salim Azad

    2016-01-01

    Full Text Available Nodulation responses of leguminous trees are very important for intercropping to reduce reliance on artificial nitrogen input through nitrogen fixation in agroforestry system. This study was carried out to evaluate the status of nodulation (i.e., the number of nodules and their shape and size in root and biomass production of plant growth parameters (i.e., number of leaves, shoot height, root biomass, and shoot biomass of A. auriculiformis seedlings. The assessment was conducted 60 days after seed germination. The study revealed significant differences in nodule number per seedling, leaf number per seedling, shoot height, and biomass accumulation (both green and oven dry weight with seedling age (p<0.05. The study also revealed significant correlation among the variables of nodulation responses and biomass production. The results obtained using principal component analysis (PCA justified correlation matrix of nodulation responses and biomass production of this species. The PCA showed that root biomass per seedling, leaf number per seedling, nodule number per seedling, shoot height, age of seedling, and shoot biomass per seedling were clustered with PC1 (with an eigenvalue of 5.59 and root shoot ratios were clustered with PC2 (with an eigenvalue of 1.82. Our study justified that shoot height may be an important determinant of nodule formation of A. auriculiformis.

  1. Growth and energetics of a small shorebird species in a cold environment : the little stint Calidris minuta on the Taimyr Peninsula, Siberia

    NARCIS (Netherlands)

    Tjorve, Kathleen M. C.; Schekkerman, Hans; Tulp, Ingrid; Underhill, Leslie G.; de Leeuw, Joep J.; Visser, G. Henk

    The little stint Calidris minuta is one of the smallest shorebird species breeding in the Arctic (weighing 4.3 g on hatching). Their chicks are small and have a high surface area-to-volume ratio. We determined prefledging growth, energy expenditure and time budgets for little stint chicks in

  2. Coping with low nutrient availability and inundation: root growth responses of three halophytic grass species from different elevations along a flooding gradient

    NARCIS (Netherlands)

    Bouma, T.J.; Koutstaal, B.P.; Van Dongen, M.; Nielsen, K.F.

    2001-01-01

    We describe the responses of three halophytic grass species that dominate the low (Spartina anglica), middle (Puccinellia maritima) and high (Elymus pycnanthus) parts of a salt marsh, to soil conditions that are believed to favour contrasting root-growth strategies. Our hypotheses were: (1)

  3. Changes in the onset of spring growth in shrubland species in response to experimental warming along a north-south gradient in Europe

    DEFF Research Database (Denmark)

    Prieto, Patricia; Penuelas, Josep; Niinemets, Üelo

    2009-01-01

    Species responsive to increased temperatures were Vaccinium myrtillus and Empetrum nigrum in Wales, Deschampsia flexuosa in Denmark, Calluna vulgaris in Netherlands, Populus alba in Hungary and Erica multiflora in Spain. Although the acceleration of spring growth was the commonest response to warming...

  4. [Dynamics and modeling of water content of ten shrub species in their growth period in Maoershan Mountain region of Northeast China].

    Science.gov (United States)

    Jin, Sen; Yan, Xue-Jiao

    2012-12-01

    Based on the two successive years observation of the water content of ten representative shrub species in Maoershan Mountain region of Northeast China, this paper studied the dynamics of the water content of these shrub species during their growth period and related affecting factors, with the prediction models of the shrub water content established. For the ten shrub species, their minimal water content during growth period was higher than 100% , and most of the species had a water content higher than 200% within the period from the late phase of leaf-unfolding to early phase of leaf-falling. Euonymus verrucosus, Sorbaria sorbifolia, and Sambucus williamsii were incombustible in their whole growth period due to the extremely high water content, while Syringa reticulate, Philadelphus schrenkii, Euonymus verrucosus, Spiraea chamaedryfolia, Lonicera maackii, Lonicera ruprechtiana, and Rhamnus parvifolia were combustible only in the phases of budding and leaf-falling. Soil moisture content and daily maximum temperature had effects on the water content of most (7) of the ten shrubs, and canopy drought severity index affected the water content of 5 of the ten shrubs. The established 9 prediction models could explain more than 35% of the water content variance of the shrub species, with a mean MRE of 35.9% and a mean MRE of 13.4%.

  5. Comparison of Rooting Strategies to Explore Rock Fractures for Shallow Soil-Adapted Tree Species with Contrasting Aboveground Growth Rates: A Greenhouse Microcosm Experiment

    Directory of Open Access Journals (Sweden)

    Yunpeng Nie

    2017-09-01

    Full Text Available For tree species adapted to shallow soil environments, rooting strategies that efficiently explore rock fractures are important because soil water depletion occurs frequently. However, two questions: (a to what extent shallow soil-adapted species rely on exploring rock fractures and (b what outcomes result from drought stress, have rarely been tested. Therefore, based on the expectation that early development of roots into deep soil layers is at the cost of aboveground growth, seedlings of three tree species (Cyclobalanopsis glauca, Delavaya toxocarpa, and Acer cinnamomifolium with distinct aboveground growth rates were selected from a typical shallow soil region. In a greenhouse experiment that mimics the basic features of shallow soil environments, 1-year-old seedlings were transplanted into simulated microcosms of shallow soil overlaying fractured bedrock. Root biomass allocation and leaf physiological activities, as well as leaf δ13C values were investigated and compared for two treatments: regular irrigation and repeated cycles of drought stress. Our results show that the three species differed in their rooting strategies in the context of encountering rock fractures, however, these strategies were not closely related to the aboveground growth rate. For the slowest-growing seedling, C. glauca, percentages of root mass in the fractures, as well as in the soil layer between soil and bedrock increased significantly under both treatments, indicating a specialized rooting strategy that facilitated the exploration of rock fractures. Early investment in deep root growth was likely critical to the establishment of this drought-vulnerable species. For the intermediate-growing, A. cinnamomifolium, percentages of root mass in the bedrock and interface soil layers were relatively low and exhibited no obvious change under either treatment. This limited need to explore rock fractures was compensated by a conservative water use strategy. For the fast

  6. Effect of water stress on seedling growth in two species with different abundances: the importance of Stress Resistance Syndrome in seasonally dry tropical forest

    Directory of Open Access Journals (Sweden)

    Wanessa Nepomuceno Ferreira

    2015-09-01

    Full Text Available ABSTRACTIn seasonally dry tropical forests, species carrying attributes of Stress Resistance Syndrome (SRS may have ecological advantages over species demanding high quantities of resources. In such forests, Poincianella bracteosa is abundant, while Libidibia ferrea has low abundance; therefore, we hypothesized that P. bracteosa has characteristics of low-resource species, while L. ferrea has characteristics of high-resource species. To test this hypothesis, we assessed morphological and physiological traits of seedlings of these species under different water regimes (100%, 70%, 40%, and 10% field capacity over 85 days. For most of the studied variables we observed significant decreases with increasing water stress, and these reductions were greater in L. ferrea. As expected, L. ferreamaximized their growth with increased water supply, while P. bracteosa maintained slower growth and had minor adjustments in biomass allocation, characteristics representative of low-resource species that are less sensitive to stress. We observed that specific leaf area, biomass allocation to roots, and root/shoot ratio were higher in L. ferrea, while biomass allocation to leaves and photosynthesis were higher in P. bracteosa. Results suggest that the attributes of SRS can facilitate high abundance of P. bracteosa in dry forest.

  7. Characterizing the growth responses of three co-occurring northern conifer tree species to climate variation across a range of conditions

    Energy Technology Data Exchange (ETDEWEB)

    Green, S.; Miyamoto, Y. [Northern British Columbia Univ., Prince George, BC (Canada). Ecosystem Science and Management Program

    2006-07-01

    Climate is the key factor affecting tree growth. Trees regularly adapt to changing environmental conditions. Adjusting forest policies and practices under changing environments necessitates an understanding of species-specific tree responses to climate change. This paper discussed a study that examined the responses of 3 northern conifer tree species, notably the lodgepole pine, subalpine fir, and interior spruce. The purpose of the study was to characterize the climate sensitivities of each species growing under various environmental conditions, represented by mean annual temperatures and mean annual precipitations. The paper provided background information on climate change and tree species and discussed the objectives and implications of the study. Study methods were presented in detail and a geographical map showing the eight sampling sites located in central British Columbia and Yukon was also provided. Last, the paper provided the preliminary results and conclusions. It was found that the impacts of changing seasonal climates on tree growth will be species and site-specific. However, the magnitude of these differences were not completely analysed so that the impacts may be similar or significantly different among species or sites. 15 refs., 4 figs.

  8. Modification of growth medium of mixed-culture species of microalgae isolated from southern java coastal region

    Directory of Open Access Journals (Sweden)

    Sudibyo Hanifrahmawan

    2018-01-01

    Full Text Available Globally, there is growing interest in microalgae as production organisms. Microalgae contain lipids (oil, proteins and carbohydrates (sugars, and, especially marine algae have been used as food and feed for centuries. Recently, production cost reduction related to the supply of growth nutrients is necessary to make it profitable. Therefore, utilization of molasses, a byproduct of sugar production, as the natural carbon, macronutrients, and micronutrients sources can be helpful. The analysis showed that the content of sucrose, glucose, fructose, potassium, zinc, and magnesium was 68.4% w/w, 18.5% w/w, and 13.1% w/w, 5.5% w/w, 3.91 ppm, and 1,370 ppm respectively. This work aimed to determine the effect of molasses addition to the physio-chemical properties of multi-culture species of microalgae isolated from southern Java coastal region in Indonesia grown under mixotrophic culture. The cultivation in this work used medium which was self-formulated by the authors consisting of NaNO3 (5 mL/L, H3BO3 (1 mL/L, EDTA (1 mL/L, N2H2PO4 (5 mL/L, FeSO4 (1 mL/L, MgSO4 (1 mL/L, NaCl (1 mL/L, micronutrients (1 mL/L, vitamin B1 (1 mL/L, and vitamin B12 (1 mL/L in 500 mL of water. The medium will be treated to have molasses concentration of 0.05% v/v, 0.15% v/v, 0.25% v/v, 0.35% v/v, and 0.45% v/v.

  9. Comparing the acute sensitivity of growth and photosynthetic endpoints in three Lemna species exposed to four herbicides.

    Science.gov (United States)

    Park, Jihae; Brown, Murray T; Depuydt, Stephen; Kim, Jang K; Won, Dam-Soo; Han, Taejun

    2017-01-01

    An ecological impact assessment of four herbicides (atrazine, diuron, paraquat and simazine) was assessed using the aquatic floating vascular plants, Lemna gibba, Lemna minor and Lemna paucicostata as test organisms. The sensitivity of several ecologically relevant parameters (increase in frond area, root length after regrowth, maximum and effective quantum yield of PSII and maximum electron transport rate (ETR max ), were compared after a 72 h exposure to herbicides. The present test methods require relatively small sample volume (3 mL), shorter exposure times (72 h), simple and quick analytical procedures as compared with standard Lemna assays. Sensitivity ranking of endpoints, based on EC 50 values, differed depending on the herbicide. The most toxic herbicides were diuron and paraquat and the most sensitive endpoints were root length (6.0-12.3 μg L -1 ) and ETR max (4.7-10.3 μg L -1 ) for paraquat and effective quantum yield (6.8-10.4 μg L -1 ) for diuron. Growth and chlorophyll a fluorescence parameters in all three Lemna species were sensitive enough to detect toxic levels of diuron and paraquat in water samples in excess of allowable concentrations set by international standards. CV values of all EC 50 s obtained from the Lemna tests were in the range of 2.8-24.33%, indicating a high level of repeatability comparable to the desirable level of herbicides in aquatic ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Growth of four tropical tree species in petroleum-contaminated soil and effects of crude oil contamination

    NARCIS (Netherlands)

    Pérez-Hernández, I.; Ochoa-Gaona, S.; Adams, R.H.; Rivera-Cruz, M.C.; Pérez-Hernández, V.; Jarquín-Sánchez, A.; Geissen, V.; Martínez-Zurimendi, P.

    2017-01-01

    Under greenhouse conditions, we evaluated establishment of four tree species and their capacity to degrade crude oil recently incorporated into the soil; the species were as follows: Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia macrophylla (mahogany), and

  11. 18 excel spreadsheets by species and year giving reproduction and growth data. One excel spreadsheet of herbicide treatment chemistry.

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excel spreadsheets by species (4 letter code is abbreviation for genus and species used in study, year 2010 or 2011 is year data collected, SH indicates data for...

  12. Effects of Drought, Pest Pressure and Light Availability on Seedling Establishment and Growth: Their Role for Distribution of Tree Species across a Tropical Rainfall Gradient.

    Directory of Open Access Journals (Sweden)

    Julian Gaviria

    Full Text Available Tree species distributions associated with rainfall are among the most prominent patterns in tropical forests. Understanding the mechanisms shaping these patterns is important to project impacts of global climate change on tree distributions and diversity in the tropics. Beside direct effects of water availability, additional factors co-varying with rainfall have been hypothesized to play an important role, including pest pressure and light availability. While low water availability is expected to exclude drought-intolerant wet forest species from drier forests (physiological tolerance hypothesis, high pest pressure or low light availability are hypothesized to exclude dry forest species from wetter forests (pest pressure gradient and light availability hypothesis, respectively. To test these hypotheses at the seed-to-seedling transition, the potentially most critical stage for species discrimination, we conducted a reciprocal transplant experiment combined with a pest exclosure treatment at a wet and a dry forest site in Panama with seeds of 26 species with contrasting origin. Establishment success after one year did not reflect species distribution patterns. However, in the wet forest, wet origin species had a home advantage over dry forest species through higher growth rates. At the same time, drought limited survival of wet origin species in the dry forest, supporting the physiological tolerance hypothesis. Together these processes sort species over longer time frames, and exclude species outside their respective home range. Although we found pronounced effects of pests and some effects of light availability on the seedlings, they did not corroborate the pest pressure nor light availability hypotheses at the seed-to-seedling transition. Our results underline that changes in water availability due to climate change will have direct consequences on tree regeneration and distributions along tropical rainfall gradients, while indirect effects of

  13. Effects of Drought, Pest Pressure and Light Availability on Seedling Establishment and Growth: Their Role for Distribution of Tree Species across a Tropical Rainfall Gradient.

    Science.gov (United States)

    Gaviria, Julian; Engelbrecht, Bettina M J

    2015-01-01

    Tree species distributions associated with rainfall are among the most prominent patterns in tropical forests. Understanding the mechanisms shaping these patterns is important to project impacts of global climate change on tree distributions and diversity in the tropics. Beside direct effects of water availability, additional factors co-varying with rainfall have been hypothesized to play an important role, including pest pressure and light availability. While low water availability is expected to exclude drought-intolerant wet forest species from drier forests (physiological tolerance hypothesis), high pest pressure or low light availability are hypothesized to exclude dry forest species from wetter forests (pest pressure gradient and light availability hypothesis, respectively). To test these hypotheses at the seed-to-seedling transition, the potentially most critical stage for species discrimination, we conducted a reciprocal transplant experiment combined with a pest exclosure treatment at a wet and a dry forest site in Panama with seeds of 26 species with contrasting origin. Establishment success after one year did not reflect species distribution patterns. However, in the wet forest, wet origin species had a home advantage over dry forest species through higher growth rates. At the same time, drought limited survival of wet origin species in the dry forest, supporting the physiological tolerance hypothesis. Together these processes sort species over longer time frames, and exclude species outside their respective home range. Although we found pronounced effects of pests and some effects of light availability on the seedlings, they did not corroborate the pest pressure nor light availability hypotheses at the seed-to-seedling transition. Our results underline that changes in water availability due to climate change will have direct consequences on tree regeneration and distributions along tropical rainfall gradients, while indirect effects of light and pests

  14. Growth and photosynthetic performance of five tree seedlings species in response to natural light regimes from the Central Pacific of Costa Rica.

    Science.gov (United States)

    Guzmán, J Antonio; Cordero, Roberto A

    2013-09-01

    Environmental heterogeneity mostly dominated by differing light regimes affects the expression of phenotypic plasticity, which is important for plant growth and survival, especially in the forest understory. The knowledge about these responses to this heterogeneity is a key factor for forest restoration initiatives. In this study, we determine several phenotypic responses to contrasting light conditions in five native tree seedling species of La Cangreja National Park, Central Pacific of Costa Rica, four of them with threatened or relict populations. After 14 weeks at a medium gap condition (24% of full sun), seedlings were transferred and acclimated for 11 weeks to three different natural light regimes: large gap (LG), medium gap (MG) and small gap (SG), corresponding to 52%, 24%, 9% of the mean direct and indirect radiation at each site from full sun. Growth, biomass allocation and leaf gas exchange were measured after the acclimation period. Four species strongly reduced relative growth rate (RGR) in the lower light condition. Total biomass (TB) and RGR were different in Hymenaea courbaril and Platymiscium curiense. H. courbaril and Astronium graveolens had significant changes in the maximum assimilation rate, with a mean value in the LG of 11.02 and 7.70 micromolCO2/m2s, respectively. P. curuense showed the same trend and significant changes in RGR and biomass allocation. Aspidosperma myristicifolium and Plinia puriscalensis showed no adjustments to the light regimes in any of the measured variables. This study remarks the importance of determining the growth and physiological performance of these tree native species. It also demonstrates that the most threatened species are those with the less plastic responses to the light regimes, which stresses the difficult situation of their natural populations. This study highlights an urgent definition of the conservation and restoration needs of the degraded forests of the Costa Rican Central Pacific area, where these

  15. Growth and photosynthetic performance of five tree seedlings species in response to natural light regimes from the Central Pacific of Costa Rica

    Directory of Open Access Journals (Sweden)

    J. Antonio Guzmán Q.

    2013-09-01

    Full Text Available Environmental heterogeneity mostly dominated by differing light regimes affects the expression of phenotypic plasticity, which is important for plant growth and survival, especially in the forest understory. The knowledge about these responses to this heterogeneity is a key factor for forest restoration initiatives. In this study, we determine several phenotypic responses to contrasting light conditions in five native tree seedling species of La Cangreja National Park, Central Pacific of Costa Rica, four of them with threatened or relict populations. After 14 weeks at a medium gap condition (24% of full sun, seedlings were transferred and acclimated for 11 weeks to three different natural light regimes: large gap (LG, medium gap (MG and small gap (SG, corresponding to 52%, 24%, 9% of the mean direct and indirect radiation at each site from full sun. Growth, biomass allocation and leaf gas exchange were measured after the acclimation period. Four species strongly reduced relative growth rate (RGR in the lower light condition. Total biomass (TB and RGR were different in Hymenaea courbaril and Platymiscium curiense. H. courbaril and Astronium graveolens had significant changes in the maximum assimilation rate, with a mean value in the LG of 11.02 and 7.70µmolCO2/m²s, respectively. P. curuense showed the same trend and significant changes in RGR and biomass allocation. Aspidosperma myristicifolium and Plinia puriscalensis showed no adjustments to the light regimes in any of the measured variables. This study remarks the importance of determining the growth and physiological performance of these tree native species. It also demonstrates that the most threatened species are those with the less plastic responses to the light regimes, which stresses the difficult situation of their natural populations. This study highlights an urgent definition of the conservation and restoration needs of the degraded forests of the Costa Rican Central Pacific area

  16. Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality.

    Directory of Open Access Journals (Sweden)

    Michał Filipiak

    Full Text Available The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees' need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1 ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover or (2 prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower. Since pollen is generally poor in Na, this element must be supplemented using "dirty water". Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base

  17. Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality.

    Science.gov (United States)

    Filipiak, Michał; Kuszewska, Karolina; Asselman, Michel; Denisow, Bożena; Stawiarz, Ernest; Woyciechowski, Michał; Weiner, January

    2017-01-01

    The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees' need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1) ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover) or (2) prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower). Since pollen is generally poor in Na, this element must be supplemented using "dirty water". Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base for bees.

  18. The effect of lichen-dominated biological soil crusts on growth and physiological characteristics of three plant species in a temperate desert of northwest China.

    Science.gov (United States)

    Zhuang, W W; Serpe, M; Zhang, Y M

    2015-11-01

    Biocrusts (biological soil crusts) cover open spaces between vascular plants in most arid and semi-arid areas. Information on effects of biocrusts on seedling growth is controversial, and there is little information on their effects on plant growth and physiology. We examined impacts of biocrusts on growth and physiological characteristics of three habitat-typical plants, Erodium oxyrhynchum, Alyssum linifolium and Hyalea pulchella, growing in the Gurbantunggut Desert, northwest China. The influence of biocrusts on plant biomass, leaf area, leaf relative water content, photosynthesis, maximum quantum efficiency of PSII (F(v)/F(m)), chlorophyll, osmotic solutes (soluble sugars, protein, proline) and antioxidant enzymes (superoxide dismutase, catalase, peroxidase) was investigated on sites with or without biocrust cover. Biomass, leaf area, leaf water content, photosynthesis, F(v)/F(m) and chlorophyll content in crusted soils were higher than in uncrusted soils during early growth and lower later in the growth period. Soluble sugars, proline and antioxidant enzyme activity were always higher in crusted than in uncrusted soils, while soluble protein content was always lower. These findings indicate that biocrusts have different effects on these three ephemeral species during growth in this desert, primarily via effects on soil moisture, and possibly on soil nutrients. The influence of biocrusts changes during plant development: in early plant growth, biocrusts had either positive or no effect on growth and physiological parameters. However, biocrusts tended to negatively influence plants during later growth. Our results provide insights to explain why previous studies have found different effects of biocrusts on vascular plant growth. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Coagulation increased the growth potential of various species bacteria of the effluent of a MBR for the treatment of domestic wastewater.

    Science.gov (United States)

    Yu, Tong; Li, Guoqiang; Lin, Wenqi; Hu, Hong-Ying; Lu, Yun

    2017-02-01

    Microbial regrowth in reclaimed water is an important issue restricting water reclamation and reuse. Previous studies about the effect of coagulation on microbial growth in reclaimed water were limited and inconsistent. In this study, microbial growth potentials of the effluent of a membrane bioreactor (MBR) for the treatment of domestic wastewater after coagulation was evaluated by using bacteria of various phyla, classes (α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, and Actinobacteriaa) or species isolated from wastewater treatment plants (WWTPs) and assimilable organic carbon (AOC) test strains. Bacterial growth increased considerably after coagulation with polyaluminum for the samples investigated in this study. The results revealed that the microbial growth potentials in the effluent of the MBR evidently increased after coagulation. The increase ratio of bacterial growth could reach up to 929 %. Specific UV absorbance (SUVA) of the samples averagely decreased 16.3 %, but the removal efficiencies of the excitation emission matrices (EEMs) were less than 5 % after coagulation. It is suggested that the organic matter which affected the bacterial growth might be substances having aromaticity (i.e., UV 254 absorbance) but little fluorescence. According to molecular weight (MW) distribution analysis, the coagulation was indeed effective in removing organic matters with large MW. The removal of large MW organic matters might be related to bacterial growth increase. The results indicated that posttreatments are needed after coagulation to maintain the biological stability of reclaimed water.

  20. Differences in internalization and growth of Escherichia coli O157:H7 within the apoplast of edible plants, spinach and lettuce, compared with the model species Nicotiana benthamiana.

    Science.gov (United States)

    Wright, Kathryn M; Crozier, Louise; Marshall, Jacqueline; Merget, Bernhard; Holmes, Ashleigh; Holden, Nicola J

    2017-05-01

    Internalization of food-borne bacteria into edible parts of fresh produce plants represents a serious health risk. Therefore, internalization of verocytotoxigenic E. coli O157:H7 isolate Sakai was assessed in two species associated with outbreaks, spinach (Spinacia oleracea) and lettuce (Lactuca sativa) and compared to the model species Nicotiana benthamiana. Internalization occurred in the leaves and roots of spinach and lettuce throughout a 10 day time-course. The plant species, tissue type and inoculum dose all impacted the outcome. A combination of low inoculum dose (~10 2 CFU) together with light microscopy imaging highlighted marked differences in the fate of endophytic E. coli O157:H7 Sakai. In the fresh produce species, bacterial growth was restricted but viable cells persisted over 20 days, whereas there was > 400-fold (~2.5 Log 10 ) increase in growth in N. benthamiana. Colony formation occurred adjacent to epidermal cells and mesophyll cells or close to vascular bundles of N. benthamiana and contained components of a biofilm matrix, including curli expression and elicitation, extracellular DNA and a limited presence of cellulose. Together the data show that internalization is a relevant issue in crop production and that crop species and tissue need to be considered as food safety risk parameters. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  1. Trends in seedling growth and carbon-use efficiency vary among broadleaf tree species along a latitudinal transect in eastern North America.

    Science.gov (United States)

    Dillaway, Dylan N; Kruger, Eric L

    2014-03-01

    Factors constraining the geographic ranges of broadleaf tree species in eastern North America were examined in common gardens along a ~1500 km latitudinal transect travers in grange boundaries of four target species: trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) to the north vs. eastern cottonwood (Populus deltoides) and sweet gum (Liquidambar styraciflua) to the south. In 2006 and 2007, carbon-use efficiency (CUE), the proportion of assimilated carbon retained in biomass, was estimated for seedlings of the four species as the quotient of relative growth rate (RGR) and photosynthesis per unit tree mass (Atree ). In aspen and birch, CUE and RGR declined significantly with increasing growth temperature, which spanned 9 °C across gardens and years. The 37% (relative) CUE decrease from coolest to warmest garden correlated with increases in leaf nighttime respiration (Rleaf ) and the ratio of Rleaf to leaf photosynthesis (R%A ). For cottonwood and sweet gum, however, similar increases in Rleaf and R%A accompanied modest CUE declines, implying that processes other than Rleaf were responsible for species differences in CUE's temperature response. Our findings illustrate marked taxonomic variation, at least among young trees, in the thermal sensitivity of CUE, and point to potentially negative consequences of climate warming for the carbon balance, competitive ability, and persistence of two foundation species in northern temperate and boreal forests. © 2013 John Wiley & Sons Ltd.

  2. Genetic Diversity of Nitrogen-Fixing and Plant Growth PromotingPseudomonasSpecies Isolated from Sugarcane Rhizosphere.

    Science.gov (United States)

    Li, Hai-Bi; Singh, Rajesh K; Singh, Pratiksha; Song, Qi-Qi; Xing, Yong-Xiu; Yang, Li-Tao; Li, Yang-Rui

    2017-01-01

    The study was designed to isolate and characterize Pseudomonas spp. from sugarcane rhizosphere, and to evaluate their plant- growth- promoting (PGP) traits and nitrogenase activity. A biological nitrogen-fixing microbe has great potential to replace chemical fertilizers and be used as a targeted biofertilizer in a plant. A total of 100 isolates from sugarcane rhizosphere, belonging to different species, were isolated; from these, 30 isolates were selected on the basis of preliminary screening, for in vitro antagonistic activities against sugarcane pathogens and for various PGP traits, as well as nitrogenase activity. The production of IAA varied from 312.07 to 13.12 μg mL -1 in tryptophan supplemented medium, with higher production in AN15 and lower in CN20 strain. The estimation of ACC deaminase activity, strains CY4 and BA2 produced maximum and minimum activity of 77.0 and 15.13 μmoL mg -1 h -1 . For nitrogenase activity among the studied strains, CoA6 fixed higher and AY1 fixed lower in amounts (108.30 and 6.16 μmoL C 2 H 2 h -1 mL -1 ). All the strains were identified on the basis of 16S rRNA gene sequencing, and the phylogenetic diversity of the strains was analyzed. The results identified all strains as being similar to Pseudomonas spp. Polymerase chain reaction (PCR) amplification of nifH and antibiotic genes was suggestive that the amplified strains had the capability to fix nitrogen and possessed biocontrol activities. Genotypic comparisons of the strains were determined by BOX, ERIC, and REP PCR profile analysis. Out of all the screened isolates, CY4 ( Pseudomonas koreensis ) and CN11 ( Pseudomonas entomophila ) showed the most prominent PGP traits, as well as nitrogenase activity. Therefore, only these two strains were selected for further studies; Biolog profiling; colonization through green fluorescent protein (GFP)-tagged bacteria; and nifH gene expression using quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The Biolog

  3. Antimicrobial Effect of 15 Medicinal Plant Species and their Dependency on Climatic Conditions of Growth in Different Geographical and Ecological Areas of Fars Province

    Directory of Open Access Journals (Sweden)

    Abbas Abdollahi

    2012-05-01

    Full Text Available Background: The effects of medicinal plants are variable in different conditions. Here, the antimicrobial effect of 15 medicinal plant species and their dependency on the climatic condition of growth in different geographical and ecological areas of Fars Province were studied. Materials and Methods: In This empirical study, the antimicrobial effect of hydro-alcoholic extract of 15 medicinal plant species was examined against standard bacterial strains comparing to conventional therapeutic antibiotics using disk diffusion assay and serial broth dilution. Results: All Extracts were effective against S.aureus ATCC 25923 growth; also Peganum harmala, Myrtus communis, Mentha pulegium, Mentha spp, and Zataria multiflora extracts were observed to have antimicrobial activity against E.coli ATCC 25922. This antimicrobial activity had partially similar results, comparing to conventional antibioticsConclusion: Medicinal plants produce various amounts of antimicrobial substances under the climatic and ecological conditions of each zone, which must be considered in manufacturing herbal medicines.

  4. Restoration of Degraded Soil in the Nanmangalam Reserve Forest with Native Tree Species: Effect of Indigenous Plant Growth-Promoting Bacteria

    Directory of Open Access Journals (Sweden)

    Andimuthu Ramachandran

    2016-01-01

    Full Text Available Restoration of a highly degraded forest, which had lost its natural capacity for regeneration, was attempted in the Nanmangalam Reserve Forest in Eastern Ghats of India. In field experiment, 12 native tree species were planted. The restoration included inoculation with a consortium of 5 native plant growth-promoting bacteria (PGPB, with the addition of small amounts of compost and a chemical fertilizer (NPK. The experimental fields were maintained for 1080 days. The growth and biomass varied depending on the plant species. All native plants responded well to the supplementation with the native PGPB. The plants such as Pongamia pinnata, Tamarindus indica, Gmelina arborea, Wrightia tinctoria, Syzygium cumini, Albizia lebbeck, Terminalia bellirica, and Azadirachta indica performed well in the native soil. This study demonstrated, by using native trees and PGPB, a possibility to restore the degraded forest.

  5. Effects of the arbuscular mycorrhizal fungus Glomus mosseae on growth and metal uptake by four plant species in copper mine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B.D. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China)]. E-mail: bdchen@rcees.ac.cn; Zhu, Y.-G. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Duan, J. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Xiao, X.Y. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Smith, S.E. [Centre for Soil-Plant Interactions, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, South Australia 5005 (Australia)

    2007-05-15

    A greenhouse experiment was conducted to evaluate the potential role of arbuscular mycorrhizal fungi (AMF) in encouraging revegetation of copper (Cu) mine tailings. Two native plant species, Coreopsis drummondii and Pteris vittata, together with a turf grass, Lolium perenne and a leguminous plant Trifolium repens associated with and without AMF Glomus mosseae were grown in Cu mine tailings to assess mycorrhizal effects on plant growth, mineral nutrition and metal uptake. Results indicated that symbiotic associations were successfully established between G. mosseae and all plants tested, and mycorrhizal colonization markedly increased plant dry matter yield except for L. perenne. The beneficial impacts of mycorrhizal colonization on plant growth could be largely explained by both improved P nutrition and decreased shoot Cu, As and Cd concentrations. The experiment provided evidence for the potential use of local plant species in combination with AMF for ecological restoration of metalliferous mine tailings. - This study demonstrated that AM associations can encourage plant survival in Cu mine tailings.

  6. Effects of elevated CO₂, warming and precipitation change on plant growth, photosynthesis and peroxidation in dominant species from North China grassland.

    Science.gov (United States)

    Xu, Zhenzhu; Shimizu, Hideyuki; Ito, Shoko; Yagasaki, Yasumi; Zou, Chunjing; Zhou, Guangsheng; Zheng, Yuanrun

    2014-02-01

    Warming, watering and elevated atmospheric CO₂-concentration effects have been extensively studied separately; however, their combined impact on plants is not well understood. In the current research, we examined plant growth and physiological responses of three dominant species from the Eurasian Steppe with different functional traits to a combination of elevated CO₂, high temperature, and four simulated precipitation patterns. Elevated CO₂ stimulated plant growth by 10.8-41.7 % for a C₃ leguminous shrub, Caragana microphylla, and by 33.2-52.3 % for a C₃ grass, Stipa grandis, across all temperature and watering treatments. Elevated CO₂, however, did not affect plant biomass of a C₄ grass, Cleistogenes squarrosa, under normal or increased precipitation, whereas a 20.0-69.7 % stimulation of growth occurred with elevated CO₂ under drought conditions. Plant growth was enhanced in the C₃ shrub and the C₄ grass by warming under normal precipitation, but declined drastically with severe drought. The effects of elevated CO₂ on leaf traits, biomass allocation and photosynthetic potential were remarkably species-dependent. Suppression of photosynthetic activity, and enhancement of cell peroxidation by a combination of warming and severe drought, were partly alleviated by elevated CO₂. The relationships between plant functional traits and physiological activities and their responses to climate change were discussed. The present results suggested that the response to CO₂ enrichment may strongly depend on the response of specific species under varying patterns of precipitation, with or without warming, highlighting that individual species and multifactor dependencies must be considered in a projection of terrestrial ecosystem response to climatic change.

  7. Vertebrate Herbivore Browsing on Neighboring Forage Species Increases the Growth and Dominance of Siberian Alder Across a Latitudinal Transect in Northern Alaska.

    Science.gov (United States)

    McNeill, E. M.; Ruess, R. W.

    2017-12-01

    Vertebrate herbivores strongly influence plant growth and architecture, biogeochemical cycling, and successional dynamics in boreal and arctic ecosystems. One of the most notable impacts of vertebrate herbivory is on the growth and spread of alder, a chemically-defended, N-fixing shrub whose distribution in the Alaskan arctic has expanded dramatically over the past 60 years. Although herbivore effects on thin-leaf alder are well described for interior Alaskan floodplains, no work has been conducted on the effects of herbivores on Siberian alder (Alnus viridis spp fruticosa), despite the increasing importance of this species to high latitude ecosystems. We characterized browsing by snowshoe hares, moose, and willow ptarmigan on dominant shrub species across topo-edaphic sequences within 5 ecoregions along a 600 km latitudinal transect extending from interior Alaska to the North Slope. Ptarmigan browsed wind-blown lowland and alpine sites devoid of trees in all regions; moose browsed predominantly willow species in hardwood and mixed forests and were absent north of the Brooks Range; snowshoe hares selected habitats and forage based on their local density and vulnerability to predators. Browsing intensity on Siberian alder was either undetectable or low, limited primarily to hare browsing on young ramets in the northern boreal forest where hare density relative to forage availability is highest. Overall, alder height growth was positively correlated with levels of herbivory on competing shrub species. Our data support the hypothesis that vertebrate herbivore browsing is indirectly augmenting the growth, dominance, and possible spread of Siberian alder throughout its northern Alaskan range. Given the potential high rates of N-fixation inputs by Siberian alder, we believe herbivores are also having strong indirect effects on biogeochemical cycling and possibly C storage in these landscapes.

  8. Do low-mercury terrestrial resources subsidize low-mercury growth of stream fish? Differences between species along a productivity gradient.

    Directory of Open Access Journals (Sweden)

    Darren M Ward

    Full Text Available Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic resources, preventing an increase in diet-borne MeHg accumulation. We used a large-scale field study to evaluate relationships among terrestrial subsidy use, growth, and MeHg concentrations in two stream-dwelling fish species across an in-stream productivity gradient. We sampled young-of-the-year brook trout (Salvelinus fontinalis and Atlantic salmon (Salmo salar, potential competitors with similar foraging habits, from 20 study sites in streams in New Hampshire and Massachusetts that encompassed a wide range of aquatic prey biomass. Stable isotope analysis showed that brook trout used more terrestrial resources than Atlantic salmon. Over their first growing season, Atlantic salmon tended to grow larger than brook trout at sites with high aquatic prey biomass, but brook grew two-fold larger than Atlantic salmon at sites with low aquatic prey biomass. The MeHg concentrations of brook trout and Atlantic salmon were similar at sites with high aquatic prey biomass and the MeHg concentrations of both species increased at sites with low prey biomass and high MeHg in aquatic prey. However, brook trout had three-fold lower MeHg concentrations than Atlantic salmon at low-productivity, high-MeHg sites. These results suggest that differential use of terrestrial resource subsidies reversed the growth asymmetry between potential competitors across a productivity gradient and, for one species, moderated the effect of low in-stream productivity on MeHg accumulation.

  9. Particle hygroscopicity during atmospheric new particle formation events: implications for the chemical species contributing to particle growth

    Science.gov (United States)

    Wu, Z.; Birmili, W.; Poulain, L.; Poulain, L.; Merkel, M.; Fahlbusch, B.; van Pinxteren, D.; Herrmann, H.; Wiedensohler, A.

    2013-07-01

    This study examines the hygroscopicity of newly formed particles (diameters range 25-45 nm) during two atmospheric new particle formation (NPF) events in the German mid-level mountains during the Hill Cap Cloud Thuringia 2010 (HCCT-2010) field experiment. At the end of the NPF event involving clear particle growth, we measured an unusually high soluble particle fraction of 58.5% at 45 nm particle size. The particle growth rate contributed through sulfuric acid condensation only accounts for around 6.5% of the observed growth rate. Estimations showed that sulfuric acid condensation explained, however, only around 10% of that soluble particle fraction. Therefore, the formation of additional water-soluble matter appears imperative to explain the missing soluble fraction. Although direct evidence is missing, we consider water-soluble organics as candidates for this mechanism. For the case with clear growth process, the particle growth rate was determined by two alternative methods based on tracking the mode diameter of the nucleation mode. The mean particle growth rate obtained from the inter-site data comparison using Lagrangian consideration is 3.8 (± 2.6) nm h-1. During the same period, the growth rate calculated based on one site data is 5.0 nm h-1 using log-normal distribution function method. In light of the fact that considerable uncertainties could be involved in both methods, we consider both estimated growth rates consistent.

  10. Particle hygroscopicity during atmospheric new particle formation events: implications for the chemical species contributing to particle growth

    Directory of Open Access Journals (Sweden)

    Z. Wu

    2013-07-01

    Full Text Available This study examines the hygroscopicity of newly formed particles (diameters range 25–45 nm during two atmospheric new particle formation (NPF events in the German mid-level mountains during the Hill Cap Cloud Thuringia 2010 (HCCT-2010 field experiment. At the end of the NPF event involving clear particle growth, we measured an unusually high soluble particle fraction of 58.5% at 45 nm particle size. The particle growth rate contributed through sulfuric acid condensation only accounts for around 6.5% of the observed growth rate. Estimations showed that sulfuric acid condensation explained, however, only around 10% of that soluble particle fraction. Therefore, the formation of additional water-soluble matter appears imperative to explain the missing soluble fraction. Although direct evidence is missing, we consider water-soluble organics as candidates for this mechanism. For the case with clear growth process, the particle growth rate was determined by two alternative methods based on tracking the mode diameter of the nucleation mode. The mean particle growth rate obtained from the inter-site data comparison using Lagrangian consideration is 3.8 (± 2.6 nm h−1. During the same period, the growth rate calculated based on one site data is 5.0 nm h−1 using log-normal distribution function method. In light of the fact that considerable uncertainties could be involved in both methods, we consider both estimated growth rates consistent.

  11. Temperature alters the relative abundance and population growth rates of species within the Dendroctonus frontalis (Coleoptera: Curculionidae) community.

    Science.gov (United States)

    L. Evans; Richard Hoffstetter; Matthew Ayres; Kier Klepzig

    2011-01-01

    Temperature has strong effects on metabolic processes ofindividuals and demographics of populations, but effects on ecological communities are not well known. Many economically and ecologically important pest species have obligate associations with other organisms; therefore, effects of temperature on these species might be mediated by strong interactions. The southern...

  12. Growth and extremely high production of the non-indigenous invasive species Corbicula fluminea (Müller, 1774): Possible implications for ecosystem functioning

    Science.gov (United States)

    Sousa, Ronaldo; Nogueira, António J. A.; Gaspar, Miguel B.; Antunes, Carlos; Guilhermino, Lúcia

    2008-11-01

    The Asian clam Corbicula fluminea (Müller, 1774) is a major component of the River Minho estuary, almost completely dominating the benthic biomass. As part of a major study into the ecology of C. fluminea, benthic samples were collected monthly from January 2005 to August 2006. These data were then used to estimate the abundance, biomass, growth, and growth and elimination production of this non-indigenous invasive species. Corbicula fluminea growth was continuous throughout its life span. The annual 2005 growth production was estimated to be 463.778 g AFDW m -2 year -1, and the mean annual biomass was 160.651 g AFDW m -2, resulting in a P/B¯ ratio of 2.89 year -1 and a turnover time of 126.4 days. In the light of these results, C. fluminea is a fundamental element in the River Minho estuary, possibly sequestering a large portion of the carbon available for benthic production and altering the ecosystem functioning. This species should be considered when modelling the nutrient cycles and energy flow in aquatic ecosystems.

  13. Growth Behavior of E. coli, Enterococcus and Staphylococcus Species in the Presence and Absence of Sub-inhibitory Antibiotic Concentrations: Consequences for Interpretation of Culture-Based Data.

    Science.gov (United States)

    Heß, Stefanie; Gallert, Claudia

    2016-11-01

    Culture-based approaches are used to monitor, e.g., drinking water or bathing water quality and to investigate species diversity and antibiotic resistance levels in environmental samples. For health risk assessment, it is important to know whether the growing cultures display the actual abundance of, e.g., clinically relevant antibiotic resistance phenotypes such as vancomycin-resistant Enterococcus faecium/Enterococcus faecalis (VRE) or methicillin-resistant Staphylococcus aureus. In addition, it is important to know whether sub-inhibitory antibiotic concentrations, which are present in surface waters, favor the growth of antibiotic-resistant strains. Therefore, clinically relevant bacteria were isolated from different water sources and the growth behavior of 58 Escherichia coli, 71 Enterococcus, and 120 Staphylococcus isolates, belonging to different species and revealing different antibiotic resistance patterns, was studied with respect to "environmental" antibiotic concentrations. The finding that VRE could only be detected after specific enrichment can be explained by their slow growth compared to non-resistant strains. Interpreting their absence in standardized culture-based methods as nonexistent might be a fallacy. Sub-inhibitory antibiotic concentrations that were detected in sewage and receiving river water did not specifically promote antibiotic-resistant strains. Generally, those antibiotics that influenced cell metabolism directly led to slightly reduced growth rates and less than maximal optical densities after 48 h of incubation.

  14. Influence of arbuscular mycorrhizal fungi inoculum produced on-farm and phosphorus on growth and nutrition of native woody plant species from Brazil

    Directory of Open Access Journals (Sweden)

    Luis Claudio Goetten

    2016-03-01

    Full Text Available Mycorrhizal fungus inoculum produced on-farm can be used during production of woody plant seedlings to reduce costs associated with purchase of commercial inoculant and fertilization. This study aimed to test the efficiency of a mycorrhizal inoculant produced on-farm to promote growth and nutrition of woody species in combination with different levels of phosphorus. Plants were submitted to different treatments of phosphorus (0, 40 and 80 mg P/dm3 and mycorrhizal inoculation (uninoculated, and inoculation with Rhizophagus clarus [Rc] or Claroideoglomus etunicatum [Ce]. Species included were Luehea divaricata, Centrolobium robustum, Schinus terebinthifolius, Garcinia gardneriana, Cedrella fissilis, and Lafoensia pacari. The inoculum was produced using the on-farm methodology. Mycorrhizal colonization of plants inoculated with Rc and Ce ranged from 44.8 to 74.8%, except forGarcinia gardneriana. Inoculation treatment increased plant height and stem diameter of Luehea divaricata, Centrolobium robustum and Cedrella fissilis while phosphorus, inoculation and the interaction affected these parameters for G. gardneriana and Lafoensia pacari. Shoot biomass increased significantly with inoculation treatment in four species. For most species, mycorrhizal fungus inoculation and the addition of phosphorus increased the shoot phosphorus content. Mycorrhizal fungus inoculum produced on-farm successfully colonized tree seedlings and improved growth and/or nutrition under nursery conditions, producing seedlings useful for revegetation of degraded lands.

  15. A Comparison of growth on mercuric chloride for three Lemnaceae species reveals differences in growth dynamics that effect their suitability for use in either monitoring or remediating ecosystems contaminated with mercury.

    Science.gov (United States)

    Yang, Jingjing; Li, Gaojie; Bishopp, Anthony; Heenatigala, P. P. M.; Hu, Shiqi; Chen, Yan; Wu, Zhigang; Kumar, Sunjeet; Duan, Pengfei; Yao, Lunguang; Hou, Hongwei

    2018-04-01

    Mercury (Hg) is a toxic heavy metal that can alter the ecological balance when it contaminates aquatic ecosystems. Previously, researchers have used various Lemnaceae species either to monitor and/or remove heavy metals from freshwater systems. As Hg contamination is a pressing issue for aquatic systems worldwide, we assessed its impact on the growth of three commonly species of Lemnaceae - Lemna gibba 6745, Lemna minor 6580 and Spirodela polyrhiza 5543. We exposed plants to different concentrations of mercuric chloride (HgCl2) and monitored their growth, including relative growth rate, frond number, and fresh weight. These data were coupled with measurements of starch content, levels of photosynthetic pigment and the activities of antioxidant substances. The growth of all three lines showed significant negative correlations with Hg concentrations, and starch content, photosynthetic pigment, soluble protein and antioxidant enzymes levels were all clearly affected. Our results indicate that the L. gibba line used in this study was the most suitable of the three for biomonitoring of water contaminated with Hg. Accumulation of Hg was highest in the S. polyrhiza line with a bioconcentration factor over 1000, making this line the most suitable of the three tested for use in an Hg bioremediation system.

  16. Ecological studies of plants for the control of environmental pollution. IV. Growth of various plant species as influenced by soil applied cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Cha, J.W.; Kim, B.W.

    1975-03-01

    The relations of the growth response of plants, i.e. 4 species of crops, 12 species of roadside trees and 5 species of horticultural plants to cadmium (Cd) were studied in pot cultures. Growth in dry weight of corn, soybeans, barley, and wheat plants was decreased with an increase in Cd concentration. Damage to corn plants caused by Cd treatment was more or less recovered when it was grown in soil with calcium, but the other three crops did not recover. Although crop plants used here absorbed a small amount of Cd through the roots, the Cd content in the shoots was directly proportionate to the concentration of Cd added to the soil. Additions of calcium and sulfur to soil were sufficient to change the soil pH. The chlorosis on leaves caused by Cd treatment was observed in 2 species such as Euonymus japonica and Rhododendron yedoense out of 5 species of the horticultural plants, especially at 50 ppm of Cd. Euonymus japonica had symptoms of chlorosis and defoliation, and at higher concentrations the symptoms were more severe. At 200 ppm of Cd little damage was observed in Pinus koraiensis and Ginkgo biloba, but severe chlorosis was observed in Robinia pseudoacacia and Sabina chinensis, Buxus koreana, Abies holophylla and Platanus orientalis. Nevertheless, those plants that had serious damage at 200 ppm of Cd showed weakened symptoms by adding calcium to the soil. There were many Cd tolerant species out of the plants used in this experiment, such as Crassula falcata, Chrysanthemum morifolium, Hibiscus syriacus, Ligustrum ovalifolium, Liriodendron tulipeferia, and Lespedeza crytobotrys.

  17. Growth potential of Eucalyptus cypellocarpa as an alternative species for the mid-altitude summer rainfall region of South Africa

    CSIR Research Space (South Africa)

    Komakech, C

    2013-09-01

    Full Text Available Eucalyptus grandis is predominantly cultivated in the humid, warmer temperate, subtropical regions in South Africa for pulp and paper production because of its rapid growth and desirable wood properties. With forestry expanding into mid...

  18. Effects of nicotine on cell growth, migration, and production of inflammatory cytokines and reactive oxygen species by cementoblasts

    Directory of Open Access Journals (Sweden)

    Chun-San Chen

    2015-06-01

    Conclusion: Taken together, these results suggest that nicotine could inhibit the growth and migration of cementoblasts. In addition, nicotine could also induce the generation of inflammatory cytokines and ROS by cementoblasts.

  19. The relationship between tree growth patterns and likelihood of mortality: A study of two tree species in the Sierra Nevada

    Science.gov (United States)

    Das, A.J.; Battles, J.J.; Stephenson, N.L.; van Mantgem, P.J.

    2007-01-01

    We examined mortality of Abies concolor (Gord. & Glend.) Lindl. (white fir) and Pinus lambertiana Dougl. (sugar pine) by developing logistic models using three growth indices obtained from tree rings: average growth, growth trend, and count of abrupt growth declines. For P. lambertiana, models with average growth, growth trend, and count of abrupt declines improved overall prediction (78.6% dead trees correctly classified, 83.7% live trees correctly classified) compared with a model with average recent growth alone (69.6% dead trees correctly classified, 67.3% live trees correctly classified). For A. concolor, counts of abrupt declines and longer time intervals improved overall classification (trees with DBH ???20 cm: 78.9% dead trees correctly classified and 76.7% live trees correctly classified vs. 64.9% dead trees correctly classified and 77.9% live trees correctly classified; trees with DBH <20 cm: 71.6% dead trees correctly classified and 71.0% live trees correctly classified vs. 67.2% dead trees correctly classified and 66.7% live trees correctly classified). In general, count of abrupt declines improved live-tree classification. External validation of A. concolor models showed that they functioned well at stands not used in model development, and the development of size-specific models demonstrated important differences in mortality risk between understory and canopy trees. Population-level mortality-risk models were developed for A. concolor and generated realistic mortality rates at two sites. Our results support the contention that a more comprehensive use of the growth record yields a more robust assessment of mortality risk. ?? 2007 NRC.

  20. EFFECT OF ARBUSCULAR MYCORRHIZAL COLONIZATION ON EARLY GROWTH AND NUTRIENT CONTENT OF TWO PEAT­ SWAMP FOREST TREE SPECIES SEEDLINGS, Calophyllum hosei AND Ploiarium alternifolium

    Directory of Open Access Journals (Sweden)

    Maman Turjaman

    2006-03-01

    Full Text Available Tropical peat-swamp forests are one of  the largest near-surface reserves of terrestrial organic carbon,  but rnany peat-swamp forest tree species decreased due over-exploitation, forest fire and conversion of natural forests into agricultural lands. Among those species are slow-growing Calophyllum  hoseiand Ploiarium  alternifolium, two species are good for construction of boats, furniture, house building and considerable attention from pharmacological viewpoint for human healthly. This study was aimed at understanding the effects of arbuscular mycorrhizal (AM fungi on early growth of  C. hosei and P.alternifoliumunder greenhouse condition. Seedlings of C. hosei and P.alternifoliumwere inoculated with AM fungi: Glomus clarum and Glomus aggregatum ,or uninoculated under greenhouse condition during 6 months. AM colonization,   plant growth,  survival rate and  nutrient  content  (P, Zn  and B were measured. The percentage of C. hoseiand P.alternifolium ranged from 27-32% and 18-19%,  respectively. Both inoculated seedling species had greater plant  height, diameter, leaf number, shoot and root dry weight than control  seedlings.   Nutrient  content  of  inoculated  plants  were increased with AM colonization- Survival rates of  inoculated plants were higher (100%  than those of  control plants (67%. The results suggested that inoculation of AM fungi could improve the early growth of C. hoseiand P.alternifolium grown in tropical peat-swamp forest therefore  this finding has greater potential impact if this innovative technology applied in field scales which are socially acceptable, commercially profitable and environmentally friendly.

  1. Influences of salinity and shade on seedling photosynthesis and growth of two mangrove species, Rhizophora mangle and Bruguiera sexangula, introduced to Hawaii

    Science.gov (United States)

    Krauss, K.W.; Allen, J.A.

    2003-01-01

    Rhizophora mangle was first introduced to Hawaii in 1902 to promote shoreline stabilization. Intertidal competition with native and introduced salt marsh species was low, and beyond the early 1920s, mangrove forests expanded rapidly. An additional mangrove species, Bruguiera sexangula, was introduced in 1922 and currently co-occurs with R. mangle in only a few stands on the north shore and windward sides of Oahu. Where the two species overlap, R. mangle, having colonized intertidal zones first, forms nearly monospecific forest stands. To determine why R. mangle remains the dominant mangrove, we initiated a greenhouse study to compare seedling growth and photosynthetic light response of both species growing at two light levels and contrasting salinity regimes (2, 10, 32 PSU). The asymptotic nature of B. sexangula' s assimilation response is indicative of stomatal regulation, whereas only light level appears to regulate photosynthesis in R. mangle. Shifts in patterns of biomass allocation and physiological response indicate two contrasting strategies relative to sunlight and salinity. B. sexangula's strategy is characterized by slow growth with little variation under favorable conditions and morphological plasticity under stressful conditions, which allows for adjustments in carbon gain efficiency (morphological strategy). On the other hand, R. mangle's strategy involves faster growth under a wide range of environmental conditions with physiological enhancement of carbon assimilation (physiological strategy). Low salinity combined with reduced light, or simply low sunlight alone, appears to favor R. mangle and B. sexangula equally. High salinity places greater, but not overwhelming, stress on B. sexangula seedlings, but tends to favor R. mangle at higher light levels.

  2. Seed-mediated growth of gold nanocrystals: changes to the crystallinity or morphology as induced by the treatment of seeds with a sulfur species.

    Science.gov (United States)

    Zheng, Yiqun; Luo, Ming; Tao, Jing; Peng, Hsin-Chieh; Wan, Dehui; Zhu, Yimei; Xia, Younan

    2014-12-11

    We report our observation of changes to the crystallinity or morphology during seed-mediated growth of Au nanocrystals. When single-crystal Au seeds with a spherical or rod-like shape were treated with a chemical species such as S2O3(2-) ions, twin defects were developed during the growth process to generate multiply twinned nanostructures. X-ray photoelectron spectroscopy analysis indicated that the S2O3(2-) ions were chemisorbed on the surfaces of the seeds during the treatment. The chemisorbed S2O3(2-) ions somehow influenced the crystallization of Au atoms added onto the surface during a growth process, leading to the formation of twin defects. In contrast to the spherical and rod-like Au seeds, the single-crystal structure was retained to generate a concave morphology when single-crystal Au seeds with a cubic or octahedral shape were used for a similar treatment and then seed-mediated growth. The different outcomes are likely related to the difference in spatial distribution of S2O3(2-) ions chemisorbed on the surface of a seed. This approach based on surface modification is potentially extendable to other noble metals for engineering the crystallinity and morphology of nanocrystals formed via seed-mediated growth.

  3. The impact of water and temperature interactions on lag phase, growth and potential ochratoxin A production by two new species, Aspergillus aculeatinus and A. sclerotiicarbonarius, on a green coffee-based medium.

    Science.gov (United States)

    Akbar, Asya; Magan, Naresh

    2014-10-01

    Two new species of Aspergillus (A. aculeatinus, A. sclerotiicarbonarius) were previously isolated from coffee in Thailand. The objective of this study was to examine the effect of interacting environmental factors of water availability (water activity, aw) and temperature on lag phases prior to growth, growth and potential for ochratoxin A (OTA) production by three strains of each species on a green coffee-based medium for the first time. This showed that overall the growth of the three strains of each species was similar over the 20-37°C and 0.85-0.99 aw ranges. The lag phase prior to growth was coffee-based medium. This information is important as these species are part of the mycobiota of coffee and may influence OTA contamination by other ochratoxigenic species during coffee processing. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Leaf gas exchange, fv/fm ratio, ion content and growth conditions of the two moringa species under magnetic water treatment

    International Nuclear Information System (INIS)

    Hasan, M.M.; Alharby, H.F.; Hajar, A.; Hakeem, K.R.

    2017-01-01

    The current greenhouse experiment investigates the role of magnetic water on the two Moringa species (Moringa oleifera and Moringa peregrina). Both species were exposed to the magnetic field (30 mT). The magnetic water increased the plant height, leaf number, leaflet number, and internode distances in both the species, respectively. Relative water content (RWC) and leaf area in both the species showed changes under magnetic water treatment. The results showed in magnetic water treatment, the leaf gas exchange parameters such as assimilation (A), stomatal conductance (gs), transpiration rate (E), and vapor pressure deficit (VPD) were increased. Similarly, Photosynthetic pigments (Chl a, Chl b, Chl (a+b), Carotenoids), photosynthetic water use efficiency (WUE) were also increased significantly. Magnetized water had also significant effects on the maximal efficiency of PSII photochemistry (Fv/Fm). Our study suggested that magnetic water treatment could be used as an environment-friendly technology for improving the growth and physiology of Moringa species. In addition, this technology could be further incorporated into the traditional methods of agriculture for the improvement of crop plants, particularly in the arid and sub-arid areas of the world. (author)

  5. Adaptability to climate change in forestry species: drought effects on growth and wood anatomy of ponderosa pines growing at different competition levels

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. E.; Gyenge, J. E.; Urquiza, M. M.; Varela, S.

    2012-11-01

    More stressful conditions are expected due to climatic change in several regions, including Patagonia, South-America. In this region, there are no studies about the impact of severe drought events on growth and wood characteristics of the most planted forestry species, Pinus ponderosa (Doug. ex-Laws). The objective of this study was to quantify the effect of a severe drought event on annual stem growth and functional wood anatomy of pines growing at different plantation densities aiming to understand how management practices can help to increase their adaptability to climate change. Growth magnitude and period, specific hydraulic conductivity, and anatomical traits (early- and late wood proportion, lumen diameter, cell-wall thickness, tracheid length and bordered pit dimensions) were measured in the ring 2008-2009, which was formed during drought conditions. This drought event decreased annual stem growth by 30-38% and 58-65% respect to previous mean growth, in open vs. closed stand trees, respectively, indicating a higher sensitivity of the latter, which is opposite to reports from the same species growing in managed native forests in USA. Some wood anatomical variables did differ in more water stressed trees (lower cell wall thickness of early wood cells and higher proportion of small-lumen cells in late wood), which in turn did not affect wood function (hydraulic conductivity and resistance to implosion). Other anatomical variables (tracheid length, pit dimensions, early- and late wood proportion, lumen diameter of early wood cells) did not differ between tree sizes and plantation density. The results suggest that severe drought affects differentially the amount but not the function and quality of formed wood in ponderosa pine growing at different competition levels. (Author) 41 refs.

  6. Influences of air pollution on the growth of ornamental tree species-particularly with reference to SO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.W.

    1975-01-01

    For the purpose of detecting resistance to air pollution, particularly SO/sub 2/ contamination, six ornamental tree species were selected, i.e., Ginkgo biloba, Larix leptolepis, Pinus rigida, Syringa dilatata, Hibiscus syriacus, and Forsythia koreana. The sensitivity was observed and analyzed on the basis of the area ratio of smoke injury spot to the total leaf area. According to the results, the decreasing order of SO/sub 2/ sensitivity by species could be arranged as follows: (1) Hibiscus syriacus, (2) Ginkgo biloba, (3) Forsythia koreana, (4) Syringa dilatata, (5) Larix leptolepis, and (6) Pinus rigida. In general, Hibiscus syriacus and Ginkgo biloba can be grouped as the most resistant ones and Larix leptolepis and Pinus rigida as the weakest ones and Forsythia koreana and Syringa dilatata as the intermediate. Due to the sprouting ability and the formative ability of adventitious buds, the recovery from the SO/sub 2/ fumigation was prominent in Hibiscus syriacus, Syringa dilatata and Forsythia koreana. The differences in the smoke spot color were recognized by species, namely, dirt brown in Syringa dilatata, brilliant yellow brown in Pinus rigida and Ginkgo biloba, whitish yellow in Hibiscus syriacus, and red brown in Forsythia koreana. In the case of Ginkgo biloba and Larix leptolepis, the younger leaves were more resistant to SO/sub 2/ than the old ones. The sulfur content of leaves showed that on the basis of %/dry weight, broad-leaved species contained the higher amount of sulfur than the coniferous species. 15 ornamental tree species which have been growing in Seoul city were sampled from the 19 air polluted spots. The elucidated were the heavily polluted regions and the lightly polluted regions. The SO/sub 2/ absorbing capacities by species are explained in the text. 17 references.

  7. Use of the smart tongue to monitor mold growth and discriminate between four mold species grown in liquid media

    International Nuclear Information System (INIS)

    Zhao Guangying; Lin Xiaona; Dou Wenchao; Tian Shiyi; Deng Shaoping; Shi Jinqin

    2011-01-01

    A novel voltammetric electronic tongue, smart tongue, was employed to monitor the growth of mold and to differentiate between four types of mold grown in liquid medium. Principal component analysis (PCA) was used to extract the relevant information obtained by the smart tongue. Reference growth curves were based on measurements of dry weight and pH. The growth detected by the smart tongue was basically consistent with that observed by the measurement of dry weight and pH. The optimal combinations of electrodes and frequencies for monitoring growth were as follows: for Aspergillus, both the Pt and Au electrodes at 1 Hz, 10 Hz and 100 Hz; for Penicillium, the Pt and W electrodes at 100 Hz; for Mucor, the Pt, Pd and W electrodes at the three frequency segments; for Rhizopus, the Pd, Ti and Ag electrodes at the three frequency segments. The Ag electrode at 10 Hz or 100 Hz frequency could differentiate well between the four types of mold for culturing 6 h in the liquid media. Therefore, the smart tongue has a promising future as a modern rapid analytical technology for the real time detection of the growth of mold and for the classification model of mold.

  8. Use of the smart tongue to monitor mold growth and discriminate between four mold species grown in liquid media

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Guangying, E-mail: zhaogy-user@163.com [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, Hangzhou 310035 (China); Lin Xiaona; Dou Wenchao; Tian Shiyi; Deng Shaoping; Shi Jinqin [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, Hangzhou 310035 (China)

    2011-04-01

    A novel voltammetric electronic tongue, smart tongue, was employed to monitor the growth of mold and to differentiate between four types of mold grown in liquid medium. Principal component analysis (PCA) was used to extract the relevant information obtained by the smart tongue. Reference growth curves were based on measurements of dry weight and pH. The growth detected by the smart tongue was basically consistent with that observed by the measurement of dry weight and pH. The optimal combinations of electrodes and frequencies for monitoring growth were as follows: for Aspergillus, both the Pt and Au electrodes at 1 Hz, 10 Hz and 100 Hz; for Penicillium, the Pt and W electrodes at 100 Hz; for Mucor, the Pt, Pd and W electrodes at the three frequency segments; for Rhizopus, the Pd, Ti and Ag electrodes at the three frequency segments. The Ag electrode at 10 Hz or 100 Hz frequency could differentiate well between the four types of mold for culturing 6 h in the liquid media. Therefore, the smart tongue has a promising future as a modern rapid analytical technology for the real time detection of the growth of mold and for the classification model of mold.

  9. Growth analysis of three species weeds Euphorbia genus = Análise de crescimento de espécies daninhas do gênero Euphorbia

    Directory of Open Access Journals (Sweden)

    Débora Teresa Ferreira

    2017-06-01

    Full Text Available In sugarcane plantations, species of the genus Euphorbia are reported as weeds able to reduce productivity by up to 85%. Planning the correct strategies for controlling these plants requires knowledge of their biology and growth. The aim of this work therefore, was to evaluate the growth of three weed species of the genus Euphorbia occurring in sugarcane plantations. The study was carried out in a greenhouse, using a completely randomised experimental design in a scheme of lots subdivided over time, with five replications. The factors were three species of Euphorbia (E. heterophylla, E. hyssopifolia and E. hirta and 13 periods of evaluation 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91 and 98 days after sowing (DAS. Each evaluation measured plant height (PH, leaf area (LA, number of leaves (NL and total dry matter (TDM. From the mean values for shoot dry matter (SDM, TDM and LA, the absolute growth rate (AGR and relative growth rate (RGR, leaf area ratio (LAR, and leaf weight ratio (LWR were calculated. Data were submitted to analysis of variance and non-linear regression. E. heterophylla displayed greater PH up to 63 DAS, from this point E. hyssopifolia obtained greater height among the species under study. E. heterophylla was noteworthy for having a greater accumulation of LA, TDM and AGR among the studied species, followed by E. hyssopifolia and E. hirta. Maximum growth in the species under evaluation was at 77 DAS. Among the species, E. heterophylla displays greater growth and development. = Nos canaviais, espécies do gênero Euphorbia são relatadas como plantas daninhas capazes de reduzir a produtividade em até 85%. Para traçar estratégias corretas de controle dessas plantas é necessário o conhecimento tanto da sua biologia quanto do seu crescimento. Assim, objetivou-se com este trabalho avaliar o crescimento de três espécies daninhas do gênero Euphorbia ocorrentes nos canaviais. O estudo foi realizado em casa de vegeta

  10. Effects of initial climatic conditions on growth and accumulation of fluoride and nitrogen in leaves of two tropical tree species exposed to industrial air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, Claudia Maria; Salatino, Antonio [Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, CP 11461, 05422-970, Sao Paulo, SP (Brazil); Domingos, Marisa [Secao de Ecologia, Instituto de Botanica, SMA, CP 4005, 01061-970, Sao Paulo (Brazil)

    2007-03-15

    Saplings of Tibouchina pulchra and Psidium guajava, cultivated under standardized soil conditions, were placed in two sites at Cubatao (state of Sao Paulo, southeast Brazil) to study the effects of air pollution on growth, biomass allocation and foliar nitrogen and fluoride concentrations. Thirty-six potted plants were maintained over two periods of one year (Jul/00 to Jun/01; Dec/00 to Nov/01) at each of two experimental sites with distinct levels of air pollution: Piloes River Valley (PV) with vegetation virtually unaffected by air pollution; and Mogi River Valley (MV) severely affected by pollutants released mainly by chemical, fertilizer, iron and steel industries. For both species, saplings growing at MV showed alterations of growth and biomass allocation, as well as increased leaf concentrations of nitrogen and fluoride. Comparing both experimental periods, the one starting in winter (the driest season in Southeastern Brazil) seemed to affect the saplings more severely, the differences of the measured parameters between MV and PV being higher than in the second period. Multivariate analysis revealed two groups of data: one representing the MV and the other the PV saplings. For both species, saplings growing at MV showed differences in chemical composition, growth and biomass allocation, compared with the PV saplings. The results suggested that seasonal conditions of the first months of sapling exposure (summer or winter) modulate the intensity of responses to pollution stress. (author)

  11. Age and growth of three Odontesthes species from Southern Brazil (Atherinopsidae, with reference to phylogenetic constraints in their life-history

    Directory of Open Access Journals (Sweden)

    Becker F. G.

    2003-01-01

    Full Text Available The age and growth of three silverside species are described, and a discussion on possible phylogenetic constraints on life-history characteristics is presented. Samples were collected monthly between March 1992 and February 1993 in three freshwater coastal lakes. Standard length-total length (Ls-Lt and weight-length (Wt-Lt relationships studied showed interspecific differences in comparisons between juveniles and adults, males and females. Age was determined by scales. The three species presented a life-cycle duration of 4 to 5 years, with growth coefficients values (K between 0.37 and 0.63, and asymptotic lengths between 211 and 257 mm. Some interspecific differences may be useful for distinguishing between species (sexual and life-stage related patterns in Ls-Lt and Wt-Lt. The observed life-cycle ranges and maximum sizes were compared to those of other silversides and revealed a pattern coherent with available phylogenetic hypotheses at the supra-generic level, indicating that some life-history characteristics may be subject to phylogenetic constraints.

  12. Root proteome response to growth on tannery waste in three different poplar species with various adaptation abilities

    Directory of Open Access Journals (Sweden)

    Zemleduch-Barylska A.

    2013-04-01

    Full Text Available In our study we compared growth of three poplar clones (Populus tremula ×alba, P. alba ‘Villafranca” and P. nigra on chromium-containing solid tannery waste. Tolerance index of saplings ranged from only 25% for P. nigra up to 80% for P. tremula x alba. Standard morphological, chemical and biochemical analyses also confirmed significant differences in reaction of all tested clones to such growth conditions. Preliminary proteomic study showed an unequal level of changes in protein profiles from roots in different poplars.

  13. Dry matter yield, chemical composition and estimated extractable protein of legume and grass species during the spring growth

    DEFF Research Database (Denmark)

    Solati, Zeinab; Jørgensen, Uffe; Eriksen, Jørgen

    2017-01-01

    Carbohydrate and Protein System across six harvests during the spring growth. RESULTS The estimated extractable protein [g kg−1 dry matter (DM)] defined as the easily available fractions B1+B2 was significantly higher in white clover and lucerne at all harvests while, if the more cell wall attached fraction B3...... for protein production purpose in a biorefinery due to its high extractable protein content per kg DM. In order to maximise the protein production capacity, harvest should take place during early growth due to a decline in protein extractability with maturity. The final economy of the concept will depend...

  14. Recurrent sublethal warming reduces embryonic survival, inhibits juvenile growth, and alters species distribution projections under climate change.

    Science.gov (United States)

    Carlo, Michael A; Riddell, Eric A; Levy, Ofir; Sears, Michael W

    2018-01-01

    The capacity to tolerate climate change often varies across ontogeny in organisms with complex life cycles. Recently developed species distribution models incorporate traits across life stages; however, these life-cycle models primarily evaluate effects of lethal change. Here, we examine impacts of recurrent sublethal warming on development and survival in ecological projections of climate change. We reared lizard embryos in the laboratory under temperature cycles that simulated contemporary conditions and warming scenarios. We also artificially warmed natural nests to mimic laboratory treatments. In both cases, recurrent sublethal warming decreased embryonic survival and hatchling sizes. Incorporating survivorship results into a mechanistic species distribution model reduced annual survival by up to 24% compared to models that did not incorporate sublethal warming. Contrary to models without sublethal effects, our model suggests that modest increases in developmental temperatures influence species ranges due to effects on survivorship. © 2017 John Wiley & Sons Ltd/CNRS.

  15. Growth and (137)Cs uptake of four Brassica species influenced by inoculation with a plant growth-promoting rhizobacterium Bacillus pumilus in three contaminated farmlands in Fukushima prefecture, Japan.

    Science.gov (United States)

    Aung, Han Phyo; Djedidi, Salem; Oo, Aung Zaw; Aye, Yi Swe; Yokoyama, Tadashi; Suzuki, Sohzoh; Sekimoto, Hitoshi; Bellingrath-Kimura, Sonoko Dorothea

    2015-07-15

    The effectiveness of the plant growth-promoting rhizobacterium Bacillus pumilus regarding growth promotion and radiocesium ((137)Cs) uptake was evaluated in four Brassica species grown on different (137)Cs contaminated farmlands at Fukushima prefecture in Japan from June to August 2012. B. pumilus inoculation did not enhance growth in any of the plants, although it resulted in a significant increase of (137)Cs concentration and higher (137)Cs transfer from the soil to plants. The Brassica species exhibited different (137)Cs uptake abilities in the order Komatsuna>turnip>mustard>radish. TF values of (137)Cs ranged from 0.018 to 0.069 for all vegetables. Komatsuna possessed the largest root surface area and root volume, and showed a higher (137)Cs concentration in plant tissue and higher (137)Cs TF values (0.060) than the other vegetables. Higher (137)Cs transfer to plants was prominent in soil with a high amount of organic matter and an Al-vermiculite clay mineral type. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Growth and {sup 137}Cs uptake of four Brassica species influenced by inoculation with a plant growth-promoting rhizobacterium Bacillus pumilus in three contaminated farmlands in Fukushima prefecture, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Aung, Han Phyo [United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Djedidi, Salem; Oo, Aung Zaw [Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Aye, Yi Swe [Department of International Environmental and Agricultural Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Yokoyama, Tadashi; Suzuki, Sohzoh [Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan); Sekimoto, Hitoshi [Faculty of Agriculture, Utsunomiya University, 321-8505 (Japan); Bellingrath-Kimura, Sonoko Dorothea, E-mail: skimura@cc.tuat.ac.jp [Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509 (Japan)

    2015-07-15

    The effectiveness of the plant growth-promoting rhizobacterium Bacillus pumilus regarding growth promotion and radiocesium ({sup 137}Cs) uptake was evaluated in four Brassica species grown on different {sup 137}Cs contaminated farmlands at Fukushima prefecture in Japan from June to August 2012. B. pumilus inoculation did not enhance growth in any of the plants, although it resulted in a significant increase of {sup 137}Cs concentration and higher {sup 137}Cs transfer from the soil to plants. The Brassica species exhibited different {sup 137}Cs uptake abilities in the order Komatsuna > turnip > mustard > radish. TF values of {sup 137}Cs ranged from 0.018 to 0.069 for all vegetables. Komatsuna possessed the largest root surface area and root volume, and showed a higher {sup 137}Cs concentration in plant tissue and higher {sup 137}Cs TF values (0.060) than the other vegetables. Higher {sup 137}Cs transfer to plants was prominent in soil with a high amount of organic matter and an Al-vermiculite clay mineral type. - Highlights: • PGPR inoculation did not enhance plant biomass of tested plants. • PGPR inoculation resulted in higher {sup 137}Cs concentration in plants. • Komatsuna that had larger root volume showed higher {sup 137}Cs TF from soil to plants. • Soil with high SOM and Al-vermiculite caused larger {sup 137}Cs transfer to plants.

  17. Early growth interactions between a mangrove and an herbaceous salt marsh species are not affected by elevated CO2 or drought

    Science.gov (United States)

    Howard, Rebecca J.; Stagg, Camille L.; Utomo, Herry S.

    2018-01-01

    Increasing atmospheric carbon dioxide (CO2) concentrations are likely to influence future distributions of plants and plant community structure in many regions of the world through effects on photosynthetic rates. In recent decades the encroachment of woody mangrove species into herbaceous marshes has been documented along the U.S. northern Gulf of Mexico coast. These species shifts have been attributed primarily to rising sea levels and warming winter temperatures, but the role of elevated CO2 and water availability may become more prominent drivers of species interactions under future climate conditions. Drought has been implicated as a major factor contributing to salt marsh vegetation dieback in this region. In this greenhouse study we examined the effects of CO2 concentration (∼380 ppm, ∼700 ppm) and water regime (drought, saturated, flooded) on early growth of Avicennia germinans, a C3 mangrove species, and Spartina alterniflora, a C4 grass. Plants were grown in monocultures and in a mixed-species assemblage. We found that neither species responded to elevated CO2 over the 10-month duration of the experiment, and there were few interactions between experimental factors. Two effects of water regime were documented: lower A. germinanspneumatophore biomass under drought conditions, and lower belowground biomass under flooded conditions regardless of planting assemblage. Evidence of interspecific interactions was noted. Competition for aboveground resources (e.g., light) was indicated by lower S. alterniflora stem biomass in mixed-species assemblage compared to biomass in S. alterniflora monocultures. Pneumatophore biomass of A. germinans was reduced when grown in monoculture compared to the mixed-species assemblage, indicating competition for belowground resources. These interactions provide insight into how these species may respond following major disturbance events that lead to vegetation dieback. Site variation in propagule availability

  18. Influence of nitrogen sources on growth and fermentation performance of different wine yeast species during alcoholic fermentation

    DEFF Research Database (Denmark)

    Kemsawasd, Varongsiri; Monteiro Lomba Viana, Tiago; Ardö, Ylva

    2015-01-01

    In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non-Sacch...

  19. Androgens during development in a bird species with extremely sexually dimorphic growth, the brown songlark, Cinclorhamphus cruralis

    NARCIS (Netherlands)

    Isaksson, C.; Magrath, M. J. L.; Groothuis, T. G. G.; Komdeur, J.

    2010-01-01

    In birds, early exposure to androgens has been shown to influence offspring growth and begging behaviour, and has been proposed as a mechanism for the development of sexual size dimorphism (SSD). Sex specific effects during development can occur due to sex-specific allocation of maternal androgens,

  20. Colony growth of two species of Solenopsis fire ants(Hymenoptera: Formicidae) reared with crickets and beef liver

    Science.gov (United States)

    Most diets for rearing fire ants and other ants contain insects such as crickets or mealworms. Unfortunately, insect diets are expensive, especially for large rearing operations, and are not always easily available. This study was designed to examine colony growth of Solenopsis fire ants on beef liv...

  1. Sulfites inhibit the growth of four species of beneficial gut bacteria at concentrations regarded as safe for food.

    Directory of Open Access Journals (Sweden)

    Sally V Irwin

    Full Text Available Sulfites and other preservatives are considered food additives to limit bacterial contamination, and are generally regarded as safe for consumption by governmental regulatory agencies at concentrations up to 5000 parts per million (ppm. Consumption of bactericidal and bacteriostatic drugs have been shown to damage beneficial bacteria in the human gut and this damage has been associated with several diseases. In the present study, bactericidal and bacteriostatic effects of two common food preservatives, sodium bisulfite and sodium sulfite, were tested on four known beneficial bacterial species common as probiotics and members of the human gut microbiota. Lactobacillus species casei, plantarum and rhamnosus, and Streptococcus thermophilus were grown under optimal environmental conditions to achieve early log phase at start of experiments. Bacterial cultures were challenged with sulfite concentrations ranging between 10 and 3780 ppm for six hours. To establish a control, a culture of each species was inoculated into media containing no sulfite preservative. By two hours of exposure, a substantial decrease (or no increase of cell numbers (based on OD600 readings were observed for all bacteria types, in concentrations of sulfites between 250-500 ppm, compared to cells in sulfite free media. Further testing using serial dilution and drop plates identified bactericidal effects in concentrations ranging between 1000-3780 ppm on all the Lactobacillus species by 4 hours of exposure and bactericidal effects on S. thermophilus in 2000ppm NaHSO3 after 6 hours of exposure.

  2. Effects of fertilization of four hemlock species on Adelges tsugae (Hemiptera: Adelgidae) growth and feeding preference of predators.

    Science.gov (United States)

    S.V. Joseph; James Hanula

    2011-01-01

    Understanding how fertilization affects host resistance to hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera:Adelgidae), is important because fertilizers are often used to grow resistant selections to a suitable size for testing. We evaluated four hemlock species (Tsuga) under three different fertilizer regimes to assess whether fertility affected resistance to...

  3. Interactions between elevated CO2 concentration, nitrogen and water : effects on growth and water use of six perennial plant species

    NARCIS (Netherlands)

    Arp, W.J.; Mierlo, J.E.M.; Berendse, F.; Snijders, W.

    1998-01-01

    Two experiments are described in which plants of six species were grown for one full season in greenhouse compartments with 350 or 560 mol mol1 CO2. In the first experiment two levels of nitrogen supply were applied to study the interaction between CO2 and nitrogen. In the second experiment two

  4. Predicting climate change impacts on native and invasive tree species using radial growth and twenty-first century climate scenarios

    NARCIS (Netherlands)

    González-Muñoz, N.; Linares, J.C.; Castro-Díez, P.; Sass-Klaassen, U.G.W.

    2014-01-01

    The climatic conditions predicted for the twenty-first century may aggravate the extent and impacts of plant invasions, by favouring those invaders more adapted to altered conditions or by hampering the native flora. We aim to predict the fate of native and invasive tree species in the oak forests

  5. Links between belowground and aboveground resource-related traits reveal species growth strategies that promote invasive advantages.

    Directory of Open Access Journals (Sweden)

    Maria S Smith

    Full Text Available Belowground processes are rarely considered in comparison studies of native verses invasive species. We examined relationships between belowground fine root production and lifespan, leaf phenology, and seasonal nitrogen dynamics of Lonicera japonica (non-native versus L. sempervirens (native and Frangula alnus (non-native versus Rhamnus alnifolia (native, over time. First and second order fine roots were monitored from 2010 to 2012 using minirhizotron technology and rhizotron windows. 15N uptake of fine roots was measured across spring and fall seasons. Significant differences in fine root production across seasons were seen between Lonicera species, but not between Frangula and Rhamnus, with both groups having notable asynchrony in regards to the timing of leaf production. Root order and the number of root neighbors at the time of root death were the strongest predictors of root lifespan of both species pairs. Seasonal 15N uptake was higher in spring than in the fall, which did not support the need for higher root activity to correspond with extended leaf phenology. We found higher spring 15N uptake in non-native L. japonica compared to native L. sempervirens, although there was no difference in 15N uptake between Frangula and Rhamnus species. Our findings indicate the potential for fast-growing non-native Lonicera japonica and Frangula alnus to outcompete native counterparts through differences in biomass allocation, root turnover, and nitrogen uptake, however evidence that this is a general strategy of invader dominance is limited.

  6. Modulation of fatty acid composition and growth in Sporosarcina species in response to temperatures and exogenous branched-chain amino acids.

    Science.gov (United States)

    Tsuda, Kentaro; Nagano, Hideaki; Ando, Akinori; Shima, Jun; Ogawa, Jun

    2017-06-01

    Psychrotolerant endospore-forming Sporosarcina species have been predominantly isolated from minced fish meat (surimi), which is stored under refrigeration after heat treatment. To develop a better method for preserving surimi-based food products, we studied the growth and fatty acid compositions of the isolated strain S92h as well as Sporosarcina koreensis and Sporosarcina aquimarina at cold and moderate temperatures. The growth rates of strain S92h and S. koreensis were the fastest and slowest at cold temperatures, respectively, although these strains grew at a similar rate at moderate temperatures. In all three strains, the proportions of anteiso-C 15:0 and unsaturated fatty acids (UFAs) were significantly higher at cold temperatures than at moderate temperatures. Furthermore, supplementation with valine, leucine, and isoleucine resulted in proportional increases in iso-C 16:0 , iso-C 15:0 , and anteiso-C 15:0 , respectively, among the fatty acid compositions of these strains. The proportions of the UFAs were also altered by the supplementation. At cold temperatures, the growth rates of strain S92h and S. koreensis, but not of S. aquimarina, were affected by supplementation with leucine. Supplementation with isoleucine enhanced the growth of S. koreensis at cold temperatures but not that of the other strains. Valine did not affect the growth of any strain. These results indicate that anteiso-C 15:0 and UFAs both play important roles in the cold tolerance of the genus Sporosarcina and that these bacteria modulate their fatty acid compositions in response to the growth environment.

  7. Plant–Soil Feedback Effects on Growth, Defense and Susceptibility to a Soil-Borne Disease in a Cut Flower Crop: Species and Functional Group Effects

    Directory of Open Access Journals (Sweden)

    Hai-Kun Ma

    2017-12-01

    Full Text Available Plants can influence the soil they grow in, and via these changes in the soil they can positively or negatively influence other plants that grow later in this soil, a phenomenon called plant–soil feedback. A fascinating possibility is then to apply positive plant–soil feedback effects in sustainable agriculture to promote plant growth and resistance to pathogens. We grew the cut flower chrysanthemum (Dendranthema X grandiflora in sterile soil inoculated with soil collected from a grassland that was subsequently conditioned by 37 plant species of three functional groups (grass, forb, legume, and compared it to growth in 100% sterile soil (control. We tested the performance of chrysanthemum by measuring plant growth, and defense (leaf chlorogenic acid concentration and susceptibility to the oomycete pathogen Pythium ultimum. In presence of Pythium, belowground biomass of chrysanthemum declined but aboveground biomass was not affected compared to non-Pythium inoculated plants. We observed strong differences among species and among functional groups in their plant–soil feedback effects on chrysanthemum. Soil inocula that were conditioned by grasses produced higher chrysanthemum above- and belowground biomass and less leaf yellowness than inocula conditioned by legumes or forbs. Chrysanthemum had lower root/shoot ratios in response to Pythium in soil conditioned by forbs than by grasses. Leaf chlorogenic acid concentrations increased in presence of Pythium and correlated positively with chrysanthemum aboveground biomass. Although chlorogenic acid differed between soil inocula, it did not differ between functional groups. There was no relationship between the phylogenetic distance of the conditioning plant species to chrysanthemum and their plant–soil feedback effects on chrysanthemum. Our study provides novel evidence that plant–soil feedback effects can influence crop health, and shows that plant–soil feedbacks, plant disease

  8. Effect of mint (Mentha piperita L. and caraway (Carum carvi L. on the growth of some toxigenic aspergillus species and aflatoxin B1 production

    Directory of Open Access Journals (Sweden)

    Škrinjar Marija M.

    2009-01-01

    Full Text Available An inhibitory effect of various concentrations (0.0, 0.5, 1.0, 1.5 and 2,0% of mint (Mentha piperita L. and caraway (Carvum carvi L. on the growth of A. fumigatus, A. flavus and A. ochraceus was examined during 10 days of cultivation in YES medium at temperature of 25°C. Mint showed stronger inhibitory effect than caraway. Total dry weight (g/l after 10 days of the growth of A. fumigatus in YES medium with 0.5% of mint decreased by about 95%, A. flavus by 97% and A. ochraceus by about 82%. Addition of higher concentrations of mint (1.0, 1.5 and 2.0% reduced the growth of all tested species. It was poor and hardly visible. pH values of the media increased with the increase of mint concentrations. A. fumigatus showed the highest sensitivity towards caraway and A. flavus the lowest. Total dry weight (g/l after 10 days of growth of A. fumigatus in medium with 0.5% of caraway decreased by about 72% in comparison to the control. In media with higher concentrations of caraway, its growth was found to be very poor. Concentration of 1.0% of caraway reduced A. flavus growth by 15% and of 1.5% by 92%, in regard to the control. In medium with 2.0% of caraway the growth of A. flavus was observed as poor and hardly visible. The growth of A. ochraceus in medium with 0.5% of caraway decreased by about 85% comparing with control and further decrease was noticed by the increase of concentrations. In medium with 1.5% of caraway a reduction of about 95% of growth was found and under 2.0% of caraway it was poor. pH of the media also increased with the increase of caraway concentrations. Applied concentrations of mint and caraway inhibited completely the production of AB1 by A. flavus.

  9. An imputation/copula-based stochastic individual tree growth model for mixed species Acadian forests: a case study using the Nova Scotia permanent sample plot network

    Directory of Open Access Journals (Sweden)

    John A. KershawJr

    2017-09-01

    Full Text Available Background A novel approach to modelling individual tree growth dynamics is proposed. The approach combines multiple imputation and copula sampling to produce a stochastic individual tree growth and yield projection system. Methods The Nova Scotia, Canada permanent sample plot network is used as a case study to develop and test the modelling approach. Predictions from this model are compared to predictions from the Acadian variant of the Forest Vegetation Simulator, a widely used statistical individual tree growth and yield model. Results Diameter and height growth rates were predicted with error rates consistent with those produced using statistical models. Mortality and ingrowth error rates were higher than those observed for diameter and height, but also were within the bounds produced by traditional approaches for predicting these rates. Ingrowth species composition was very poorly predicted. The model was capable of reproducing a wide range of stand dynamic trajectories and in some cases reproduced trajectories that the statistical model was incapable of reproducing. Conclusions The model has potential to be used as a benchmarking tool for evaluating statistical and process models and may provide a mechanism to separate signal from noise and improve our ability to analyze and learn from large regional datasets that often have underlying flaws in sample design.

  10. Systemic depletion of L-cyst(e)ine with cyst(e)inase increases reactive oxygen species and suppresses tumor growth.

    Science.gov (United States)

    Cramer, Shira L; Saha, Achinto; Liu, Jinyun; Tadi, Surendar; Tiziani, Stefano; Yan, Wupeng; Triplett, Kendra; Lamb, Candice; Alters, Susan E; Rowlinson, Scott; Zhang, Yan Jessie; Keating, Michael J; Huang, Peng; DiGiovanni, John; Georgiou, George; Stone, Everett

    2017-01-01

    Cancer cells experience higher oxidative stress from reactive oxygen species (ROS) than do non-malignant cells because of genetic alterations and abnormal growth; as a result, maintenance of the antioxidant glutathione (GSH) is essential for their survival and proliferation. Under conditions of elevated ROS, endogenous L-cysteine (L-Cys) production is insufficient for GSH synthesis. This necessitates uptake of L-Cys that is predominantly in its disulfide form, L-cystine (CSSC), via the xCT(-) transporter. We show that administration of an engineered and pharmacologically optimized human cyst(e)inase enzyme mediates sustained depletion of the extracellular L-Cys and CSSC pool in mice and non-human primates. Treatment with this enzyme selectively causes cell cycle arrest and death in cancer cells due to depletion of intracellular GSH and ensuing elevated ROS; yet this treatment results in no apparent toxicities in mice even after months of continuous treatment. Cyst(e)inase suppressed the growth of prostate carcinoma allografts, reduced tumor growth in both prostate and breast cancer xenografts and doubled the median survival time of TCL1-Tg:p53 -/- mice, which develop disease resembling human chronic lymphocytic leukemia. It was observed that enzyme-mediated depletion of the serum L-Cys and CSSC pool suppresses the growth of multiple tumors, yet is very well tolerated for prolonged periods, suggesting that cyst(e)inase represents a safe and effective therapeutic modality for inactivating antioxidant cellular responses in a wide range of malignancies.

  11. Effects of plant leachates from four boreal understorey species on soil N mineralization, and white spruce (Picea glauca) germination and seedling growth.

    Science.gov (United States)

    Castells, Eva; Peñuelas, Josep; Valentine, David W

    2005-06-01

    Natural regeneration of white spruce (Picea glauca) after disturbance has been reported to be very poor. Here a study was made to determine whether C compounds released from understorey species growing together with white spruce could be involved in this regeneration failure, either by (1) changing soil nutrient dynamics, (2) inhibiting germination, and/or (3) delaying seedling growth. Foliage leachates were obtained from two shrubs (Ledum palustre and Empetrum hermaphroditum) and one bryophyte (Sphagnum sp.) with high phenolic compound concentrations that have been reported to depress growth of conifers in boreal forests, and, as a comparison, one bryophyte (Hylocomium splendens) with negligible phenolic compounds. Mineral soil from a white spruce forest was amended with plant leachates to examine the effect of each species on net N mineralization. Additionally, white spruce seeds and seedlings were watered with plant leachates to determine their effects on germination and growth. Leachates from the shrubs L. palustre and E. hermaphroditum contained high phenolic compound concentrations and dissolved organic carbon (DOC), while no detectable levels of C compounds were released from the bryophytes Sphagnum sp. or H. splendens. A decrease in net N mineralization was determined in soils amended with L. palustre or E. hermaphroditum leachates, and this effect was inversely proportional to the phenolic concentrations, DOC and leachate C/N ratio. The total percentage of white spruce germination and the growth of white spruce seedlings were similar among treatments. These results suggest that the shrubs L. palustre and E. hermaphroditum could negatively affect the performance of white spruce due to a decrease in soil N availability, but not by direct effects on plant physiology.

  12. Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem

    Science.gov (United States)

    Li, Qiang; Yu, Pujia; Chen, Xiaoying; Li, Guangdi; Zhou, Daowei; Zheng, Wei

    2014-01-01

    In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m−2, litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland. PMID:25110722

  13. Effects of micro-topographies on stand structure and tree species diversity in an old-growth evergreen broad-leaved forest, southwestern Japan

    Directory of Open Access Journals (Sweden)

    Tran Van Do

    2015-07-01

    Full Text Available Stand structure and species diversity were studied in correspondence with micro-topographies in an old-growth forest in southwestern Japan. The study was conducted in a 200×200m2 permanent plot, which were divided into 400 subplots using grids of 10m×10m. Subplots were categorized to four micro-topographies as crest slope (CS, head hollow (HH, upper slope (US and lower slope (LS, basing on slope of forest floor and plot position, and to two elevational zones as below 450 m and above 450 m. Tree censuses for all individuals with diameter at breast height (DBH ⩾ 5 cm were conducted in 2009 and 2013. The results indicated that CS had subplot means of living stems, dead stems, DBH, basal area (G, and basal area increment (▵G significantly higher than that in LS. While, means of recruited stems and Shannon diversity index were significantly lower. Comparing between below and above 450 m elevational zones indicated the significantly higher parameters of stand structure and species diversity in above 450 m elevational zone. The differences of edaphic conditions led to difference of density of living stems, species density, DBH, G, and ▵G among micro-topographies. Therefore, crest slope, upper slope, and higher elevational zones should be encouraged for the purposes of carbon accumulation and storage. While, the lower elevational zones should be used for the purposes of species diversity conservation.

  14. Effect of earthworm on growth of late succession plant species in postmining sites under laboratory and field conditions

    Czech Academy of Sciences Publication Activity Database

    Roubíčková, A.; Mudrák, Ondřej; Frouz, Jan

    2009-01-01

    Roč. 45, č. 7 (2009), s. 769-774 ISSN 0178-2762 R&D Projects: GA ČR(CZ) GA526/06/0728; GA AV ČR 1QS600660505; GA MŠk 2B08023 Institutional research plan: CEZ:AV0Z60660521 Keywords : earthworms * plant succession * plant growth Subject RIV: EH - Ecology, Behaviour Impact factor: 1.757, year: 2009

  15. The effect of cocoa fermentation and weak organic acids on growth and ochratoxin A production by Aspergillus species

    DEFF Research Database (Denmark)

    Copetti, Marina V.; Iamanaka, Beatriz T.; Mororó, Raimundo C.

    2012-01-01

    The acidic characteristics of cocoa beans have influence on flavor development in chocolate. Cocoa cotyledons are not naturally acidic, the acidity comes from organic acids produced by the fermentative microorganisms which grow during the processing of cocoa. Different concentrations...... by Aspergillus carbonarius in cocoa, and the effect of weak organic acids such as acetic, lactic and citric at different pH values on growth and ochratoxin A production by A. carbonarius and Aspergillus niger in culture media. A statistical difference (ρ...

  16. Improved Sprouting and Growth of Mung Plants in Chromate Contaminated Soils Treated with Marine Strains ofStaphylococcusSpecies.

    Science.gov (United States)

    Pereira, Elroy J; Fonseca, Suzana; Meena, Ram M; Ramaiah, Nagappa

    2017-12-01

    Marine bacteria possess a wide variety of bioremediation potential which is beneficial environmentally and economically. In this study, bacterial isolates from marine waters were screened for tolerance and growth in high concentrations of chromate (Cr 6+ ). Two isolates, capable of tolerating Cr 6+ concentrations 300 µg mL -1 or higher, and found to completely reduce 20 µg mL -1 Cr 6+ were grown in Cr 6+ (50 and 100 mg kg -1 ) spiked garden soil. Notably, both facilitated normal germination and growth of mung ( Vigna radiata ) seeds, which could hardly germinate in Cr 6+ spiked garden soil without either of these bacteria. In fact, large percent of mung seeds failed to sprout in the Cr 6+ spiked garden soil and could not grow any further. Apparently, chromate detoxification by marine bacterial isolates and the ability of mung plants to deal with the reduced form appear to work complementarily. This study provides an insight into marine bacterial abilities with respect to chromium and potential applications in promoting growth of leguminous plants-similar to mung in particular-in Cr 6+ contaminated soil.

  17. Net root growth and nutrient acquisition in response to predicted climate change in two contrasting heathland species

    DEFF Research Database (Denmark)

    Arndal, M.F.; Merrild, M.P.; Michelsen, A.

    2013-01-01

    Accurate predictions of nutrient acquisition by plant roots and mycorrhizas are critical in modelling plant responses to climate change.We conducted a field experiment with the aim to investigate root nutrient uptake in a future climate and studied root production by ingrowth cores, mycorrhizal...... to elevated CO2. The species-specific response to the treatments suggests different sensitivity to global change factors, which could result in changed plant competitive interactions and belowground nutrient pool sizes in response to future climate change....

  18. Improvement of plant growth and seed yield in Jatropha curcas by a novel nitrogen-fixing root associated Enterobacter species.

    Science.gov (United States)

    Madhaiyan, Munusamy; Peng, Ni; Te, Ngoh Si; Hsin I, Cheng; Lin, Cai; Lin, Fu; Reddy, Chalapathy; Yan, Hong; Ji, Lianghui

    2013-10-01

    Jatropha curcas L. is an oil seed producing non-leguminous tropical shrub that has good potential to be a fuel plant that can be cultivated on marginal land. Due to the low nutrient content of the targeted plantation area, the requirement for fertilizer is expected to be higher than other plants. This factor severely affects the commercial viability of J. curcas. We explored the feasibility to use endophytic nitrogen-fixing bacteria that are native to J. curcas to improve plant growth, biomass and seed productivity. We demonstrated that a novel N-fixing endophyte, Enterobacter sp. R4-368, was able to colonize in root and stem tissues and significantly promoted early plant growth and seed productivity of J. curcas in sterilized and non-sterilized soil. Inoculation of young seedling led to an approximately 57.2% increase in seedling vigour over a six week period. At 90 days after planting, inoculated plants showed an average increase of 25.3%, 77.7%, 27.5%, 45.8% in plant height, leaf number, chlorophyll content and stem volume, respectively. Notably, inoculation of the strain led to a 49.0% increase in the average seed number per plant and 20% increase in the average single seed weight when plants were maintained for 1.5 years in non-sterilized soil in pots in the open air. Enterobacter sp. R4-368 cells were able to colonize root tissues and moved systemically to stem tissues. However, no bacteria were found in leaves. Promotion of plant growth and leaf nitrogen content by the strain was partially lost in nifH, nifD, nifK knockout mutants, suggesting the presence of other growth promoting factors that are associated with this bacterium strain. Our results showed that Enterobacter sp. R4-368 significantly promoted growth and seed yield of J. curcas. The application of the strains is likely to significantly improve the commercial viability of J. curcas due to the reduced fertilizer cost and improved oil yield.

  19. Methods to Improve Survival and Growth of Planted Alternative Species Seedlings in Black Ash Ecosystems Threatened by Emerald Ash Borer

    Directory of Open Access Journals (Sweden)

    Nicholas Bolton

    2018-03-01

    Full Text Available Emerald ash borer (EAB continues to spread across North America, infesting native ash trees and changing the forested landscape. Black ash wetland forests are severely affected by EAB. As black ash wetland forests provide integral ecosystem services, alternative approaches to maintain forest cover on the landscape are needed. We implemented simulated EAB infestations in depressional black ash wetlands in the Ottawa National Forest in Michigan to mimic the short-term and long-term effects of EAB. These wetlands were planted with 10 alternative tree species in 2013. Based on initial results in the Michigan sites, a riparian corridor in the Superior Municipal Forest in Wisconsin was planted with three alternative tree species in 2015. Results across both locations indicate that silver maple (Acer saccharinum L., red maple (Acer rubrum L., American elm (Ulmus americana L., and northern white cedar (Thuja occidentalis L. are viable alternative species to plant in black ash-dominated wetlands. Additionally, selectively planting on natural or created hummocks resulted in two times greater survival than in adjacent lowland sites, and this suggests that planting should be implemented with microsite selection or creation as a primary control. Regional landowners and forest managers can use these results to help mitigate the canopy and structure losses from EAB and maintain forest cover and hydrologic function in black ash-dominated wetlands after infestation.

  20. Effects of temperature, salinity, and irradiance on the growth of harmful algal bloom species Phaeocystis globosa Scherffel (Prymnesiophyceae) isolated from the South China Sea

    Science.gov (United States)

    Xu, Ning; Huang, Bozhu; Hu, Zhangxi; Tang, Yingzhong; Duan, Shunshan; Zhang, Chengwu

    2017-05-01

    Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth of P. globosa ( I s) was 60 μmol/(m2•s), which was lower than those of other harmful algal species (70-114 μmol/(m2•s)). A moderate growth rate of 0.22/d was observed at 2 μmol/(m2•s) (the minimum irradiance in the experiment), and photo-inhibition did not occur at 230 μmol/(m2•s) (the maximum irradiance in the experiment). Exposed to 42 different combinations of temperatures (10-31°C) and salinities (10-40) under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24°C and 35, and 27°C and 40. The optimum growth rates (>0.80/d) were observed at temperatures ranging from 24 to 27°C and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20°C to 31°C and salinities from 20 to 40, it could not grow at temperatures lower than 15°C or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain of P. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.

  1. In vitro ecology of Seiridium cardinale and allied species: the effect of solute stress and water potential on fungal growth

    Directory of Open Access Journals (Sweden)

    Elena TURCO

    2011-05-01

    Full Text Available Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Defining the potential implications of global climate change on Mediterranean forest ecosystems requires a basic knowledge on the ecology of fungal pathogens under conditions that would stress host plants. The Mediterranean cypress (Cupressus sempervirens-Seiridium spp. pathosystem represents an important case study. In the last century, epidemics of cypress canker have killed historical plantations and the decades-long host resistance will probably break down in the future as a result of both host and pathogen adaptation to increasing temperature and decreasing summer precipitation. In this study, the effect of osmotic water stress on mycelial growth of Seiridium cardinale, S. unicorne and S. cupressi in culture was examined and compared to that of Diplodia cupressi, which is a pathogen of cypress known to be favoured by host water stress. Growth responses were evaluated on potato sucrose agar amended with KCl or NaCl to give water potentials in the range of -0.34 to -15 MPa. Mycelial growth decreased with decreasing water potential and ceased at -15 MPa, although the mycelium remained alive. Histochemical analysis conducted on S. cardinale grown at -12 MPa revealed melanization and thickening of hyphal walls, in addition to abundance of lipid-rich organelles. These results suggest that the three Seiridium spp. might survive drying cycles in cypress wood, but their tolerance is different. Successful survival strategies may partly result from changes in mycelium structure. Furthermore, S. unicorne was positively stimulated by a water potential of -3 MPa, suggesting that it may have high adaptive potential for life in a drier Mediterranean ecosystem, which is predicted to occur under scenarios of global warming. Normal 0 14 MicrosoftInternetExplorer4

  2. Comparative study of plant growth of two poplar tree species irrigated with treated wastewater, with particular reference to accumulation of heavy metals (Cd, Pb, As, and Ni).

    Science.gov (United States)

    Houda, Zarati; Bejaoui, Zoubeir; Albouchi, Ali; Gupta, Dharmendra K; Corpas, Francisco J

    2016-02-01

    Water is a scarce natural resource around the world which can hamper the socio-economic development of many countries. The Mediterranean area, especially north Africa, is known for its semi-arid to arid climate, causing serious water supply problems. Treated wastewater (TWW) is being used as an alternative strategy for recycling wastewater. It is also a potential source of nutrients for reforestation with certain plant species such as poplar trees, a useful wood resource, and even for phytoremediation purposes. In the present study, we used treated wastewater to irrigate two clones of 1-year-old poplar trees (Populus nigra cv. I-488 and Populus alba cv. MA-104) for 90 days. After a stipulated time, a comparative study was made of the effects of TWW on growth parameters, acquisition of essential minerals (Na, Fe and Zn) and pollutants (Cd, Pb, As and Ni) as well as the enrichment of secondary metabolites such as polyphenolic, flavonoid and tannin compounds which could contribute to the growth and development of poplar plants. The results of this study show that the use of TWW increased P. alba's biomass production by 36% and also enhanced its Cd and Pb accumulation capacity. We also found that P. alba has considerable potential to be used as an alternative plant species for reforestation and/or phytoremediation of toxic metals from contaminated water or effluent.

  3. Responses of Gmelina arborea, a tropical deciduous tree species, to elevated atmospheric CO2: growth, biomass productivity and carbon sequestration efficacy.

    Science.gov (United States)

    Rasineni, Girish K; Guha, Anirban; Reddy, Attipalli R

    2011-10-01

    The photosynthetic response of trees to rising CO(2) concentrations largely depends on source-sink relations, in addition to differences in responsiveness by species, genotype, and functional group. Previous studies on elevated CO(2) responses in trees have either doubled the gas concentration (>700 μmol mol(-1)) or used single large addition of CO(2) (500-600 μmol mol(-1)). In this study, Gmelina arborea, a fast growing tropical deciduous tree species, was selected to determine the photosynthetic efficiency, growth response and overall source-sink relations under near elevated atmospheric CO(2) concentration (460 μmol mol(-1)). Net photosynthetic rate of Gmelina was ~30% higher in plants grown in elevated CO(2) compared with ambient CO(2)-grown plants. The elevated CO(2) concentration also had significant effect on photochemical and biochemical capacities evidenced by changes in F(V)/F(M), ABS/CSm, ET(0)/CSm and RuBPcase activity. The study also revealed that elevated CO(2) conditions significantly increased absolute growth rate, above ground biomass and carbon sequestration potential in Gmelina which sequestered ~2100 g tree(-1) carbon after 120 days of treatment when compared to ambient CO(2)-grown plants. Our data indicate that young Gmelina could accumulate significant biomass and escape acclimatory down-regulation of photosynthesis due to high source-sink capacity even with an increase of 100 μmo lmol(-1) CO(2). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Effect of light exposure on in vitro germination and germ tube growth of eight species of rust fungi.

    Science.gov (United States)

    Buck, James W; Dong, Weibo; Mueller, Daren S

    2010-01-01

    The effects of light on urediniospore germination and germ tube elongation was studied with eight species of rust fungi that infect ornamental plants or row crops. Exposure of six species of fungi to cool white fluorescent light at 400 or 600 micromol s(-1) m(-2) for 24 h significantly reduced germination with largest decreases typically observed at 600 micromol s(-1) m(-2). Germination and germ tube elongation did not recover during 24 h dark incubation after 18 h exposure to fluorescent light at 600 micromol s(-1) m(-2), indicating the effects were not reversible. Germ tube elongation of all fungi was negatively affected by increased length of exposure to fluorescent light. Increased exposure to fluorescent light differentially affected germination of the fungi with Puccinia hemerocallidis, Phakopsora pachyrhizi, Pucciniastrum vaccinii and Puccinia menthae negatively affected and Puccinia sorghi, Puccinia triticina, Puccinia pelargonii-zonalis and Puccinia iridis relatively unaffected in 10 h incubation. Exposure of Ph. pachyrhizi and P. triticina urediniospores to sunlight rapidly reduced germination and germ tube elongation with no germination observed for Ph. pachyrhizi after 2.5 h. Germ tube elongation but not germination of hydrated urediniospores of Ph. pachyrhizi and P. triticina was significantly reduced compared to dry urediniospores exposed to 10 h fluorescent light followed by 24 h dark incubation. Exposure to fluorescent light (all fungi) or sunlight (two fungi) negatively affected urediniospore germ tube elongation. Differences observed in urediniospore germination between fungi suggest some species have co-evolved with their host for differing light conditions. Our data suggests exposure of urediniospores to strong light could inactivate rust fungi on plant surfaces or in the atmosphere.

  5. The effects of soil drying on the growth of a dominant peatland species, Carex lasiocarpa

    DEFF Research Database (Denmark)

    Yuan, Jihong; Wang, Ping; Weiner, Jacob

    2017-01-01

    The drying of wetlands due to natural and anthropogenic factors has become a serious problem globally. Understanding the tolerance of the dominant hygrophytic plants to drought would help in establishing effective management for the maintenance, protection and restoration of wetlands. We conducted...... the resource allocation, decreasing the root:shoot ratio. The rhizome length of C. lasiocarpa significantly decreased, and the tiller number also showed a decreasing trend. Our results suggest that this species could resist soil drying. But continuous soil drying would reduce carbon accumulation and increase...... carbon allocation aboveground, which would result in a decline in carbon storage in C. lasiocarpa peatlands....

  6. Histamine modulates cell growth, reactive oxygen species production and activity of antioxidant enzymes in human cell lines

    International Nuclear Information System (INIS)

    Medina, V.; Cricco, G.; Garbarino, G.; Nunez, M.; Martin, G.; Cocca, C.; Bergoc, R.M.; Rivera, E.S.

    2004-01-01

    Full text: In the present work, the capacity of Histamine (HA) to modulate cell proliferation and ROS production as well as the receptors involved in this response was investigated. Mammary normal (HBL-100) and malignant cell lines (MDA-MB-231, MCF- 7) was employed. The levels of the free radicals superoxide (O 2 - ) and hydrogen peroxide (H 2 O 2 ) and intracellular HA content were determined by flow cytometry. The activity of antioxidant enzymes, super-oxide dismutase (SOD) and catalase (CAT) were determined by kinetic spectrophotometric techniques. Cell proliferation was evaluated by the clonogenic assay. Cell lines presented intracellular levels of HA directly correlated with their malignancy. In MDA-MB-231, HA via H 2 R increased cAMP levels (EC 50 0.45 μM) producing in turn a significant inhibition on cell proliferation (p 1 R, stimulated cell growth. H 2 O 2 levels resulted inversely correlated with cell proliferation while O 2 - remained unchanged. Furthermore, HA significantly modified the activity of SOD and CAT. In normal HBL-100, HA modulates cell proliferation but in exactly the opposite range of doses. The effect on cell growth was inversely correlated with H 2 O 2 levels. The present data indicate that histamine can modulate cell proliferation via H 1 R and H 2 R. This effect is exerted in part by the modulation of antioxidant enzymes and ROS production. (author)

  7. The effect of cocoa fermentation and weak organic acids on growth and ochratoxin A production by Aspergillus species.

    Science.gov (United States)

    Copetti, Marina V; Iamanaka, Beatriz T; Mororó, Raimundo C; Pereira, José L; Frisvad, Jens C; Taniwaki, Marta H

    2012-04-16

    The acidic characteristics of cocoa beans have influence on flavor development in chocolate. Cocoa cotyledons are not naturally acidic, the acidity comes from organic acids produced by the fermentative microorganisms which grow during the processing of cocoa. Different concentrations of these metabolites can be produced according to the fermentation practices adopted in the farms, which could affect the growth and ochratoxin A production by fungi. This work presents two independent experiments carried out to investigate the effect of some fermentation practices on ochratoxin A production by Aspergillus carbonarius in cocoa, and the effect of weak organic acids such as acetic, lactic and citric at different pH values on growth and ochratoxin A production by A. carbonarius and Aspergillus niger in culture media. A statistical difference (ρproduction, with differences according to the media pH and the organic acid present. Acetic acid was the most inhibitory acid against A. carbonarius and A. niger. From the point of view of food safety, considering the amount of ochratoxin A produced, fermentation practices should be conducted towards the enhancement of acetic acid, although lactic and citric acids also have an important role in lowering the pH to improve the toxicity of acetic acid. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Species distribution and resistance patterns to growth-promoting antimicrobials of enterococci isolated from pigs and chickens in Korea.

    Science.gov (United States)

    Hwang, In Yeong; Ku, Hyun Ok; Lim, Suk Kyung; Park, Choi Kyu; Jung, Gab Su; Jung, Suk Chan; Nam, Hyang Mi

    2009-11-01

    A total of 147 Enterococcus faecium and 165 Enterococcus faecalis isolates from fecal samples of chickens and pigs at slaughterhouses in Korea were tested for their resistance to 8 growth-promoting antimicrobials commonly used in animals and quinupristin and dalfopristin. Resistance to most antimicrobials was very common among both E. faecalis and E. faecium. In particular, E. faecalis showed almost no susceptibility to all the antimicrobials tested except penicillin and flavomycin, to which 1.4% and less than 24% showed resistance, respectively. Although the prevalence of resistance was lower than in E. faecalis, E. faecium showed relatively uniform resistance to all the agents tested. Among the antimicrobials tested, virginiamycin and penicillin were the most effective against E. faecium isolates: less than 31% and 41% showed resistance to those 2 antimicrobials, respectively. Penicillin was the only agent that showed relatively strong activity against both E. faecalis and E. faecium. Resistance observed in E. faecalis and E. faecium against most antimicrobials used for growth promotion was more prevalent in Korea than in European countries. The current study is the first report of resistance against feed additive antimicrobials in enterococcal isolates from livestock in Korea.

  9. Calcification and growth rate recovery of the reef-building Pocillopora species in the northeast tropical Pacific following an ENSO disturbance

    Directory of Open Access Journals (Sweden)

    Jose de Jesús A. Tortolero-Langarica

    2017-04-01

    Full Text Available Pocilloporids are one of the major reef-building corals in the eastern tropical Pacific (ETP and also the most affected by thermal stress events, mainly those associated with El Niño/Southern Oscillation (ENSO periods. To date, coral growth parameters have been poorly reported in Pocillopora species in the northeastern region of the tropical Pacific. Monthly and annual growth rates of the three most abundant morphospecies (P. cf. verrucosa, P. cf. capitata, and P. cf. damicornis were evaluated during two annual periods at a site on the Pacific coast of Mexico. The first annual period, 2010–2011 was considered a strong ENSO/La Niña period with cool sea surface temperatures, then followed by a non-ENSO period in 2012–2013. The linear extension rate, skeletal density, and calcification rate averaged (±SD were 2.31 ± 0.11 cm yr−1, 1.65 ± 0.18 g cm−3, 5.03 ± 0.84 g cm−2 yr-1 respectively, during the strong ENSO event. In contrast, the respective non-ENSO values were 3.50 ± 0.64 cm yr−1, 1.70 ± 0.18 g cm−3, and 6.02 ± 1.36 g cm−2 yr−1. This corresponds to 52% and 20% faster linear extension and calcification rates, respectively, during non-ENSO period. The evidence suggests that Pocillopora branching species responded positively with faster growth rates following thermal anomalies, which allow them to maintain coral communities in the region.

  10. Cyclin-like F-box protein plays a role in growth and development of the three model species Medicago truncatula, Lotus japonicus, and Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Boycheva I

    2015-08-01

    Full Text Available Irina Boycheva,1 Valya Vassileva,2 Miglena Revalska,1 Grigor Zehirov,2 Anelia Iantcheva1 1Department of Functional Genetics Legumes, 2AgroBioInstitute, Department of Plant Stress Molecular Biology, Institute of Plant Physiology and Genetics, Sofia, Bulgaria Abstract: In eukaryotes, F-box proteins are one of the main components of the SCF complex that belongs to the family of ubiquitin E3 ligases, which catalyze protein ubiquitination and maintain the balance between protein synthesis and degradation. In the present study, we clarified the role and function of the gene encoding cyclin-like F-box protein from Medicago truncatula using transgenic plants of the model species M. truncatula, Lotus japonicas, and Arabidopsis thaliana generated by Agrobacterium-mediated transformation. Morphological and transcriptional analyses combined with flow cytometry and histochemistry demonstrated the participation of this protein in many aspects of plant growth and development, including processes of indirect somatic embryogenesis and symbiotic nodulation. The cyclin-like F-box gene showed expression in all plant organs and tissues comprised of actively dividing cells. The observed variations in root and hypocotyl growth, leaf and silique development, ploidy levels, and leaf parameters in the obtained transgenic lines demonstrated the effects of this gene on organ development. Furthermore, knockdown of cyclin-like F-box led to accumulation of higher levels of the G2/M transition-specific gene cyclin B1:1 (CYCB1:1, suggesting its possible role in cell cycle control. Together, the collected data suggest a similar role of the cyclin-like F-box protein in the three model species, providing evidence for the functional conservation of the studied gene. Keywords: cyclin-like F-box, model legumes, Arabidopsis thaliana, plant growth, plant development, cell cycle

  11. Alley cropping of legumes with grasses as forages : Effect of different grass species and row spacing of gliricidia on the growth and biomass production of forages

    Directory of Open Access Journals (Sweden)

    Siti Yuhaeni

    1998-12-01

    Full Text Available A study to evaluate the effect of different grass species and row spacing of gliricidia (Gliricidia sepium on the growth and biomass production of forages in an alley cropping system was conducted in two different agroclimatical zones i.e. Bogor, located at 500 m a .s .l . with an average annual rainfall of 3,112 nun/year and Sukabumi located at 900 m a .s .l . with an average annual rainfall of 1,402 mm/year . Both locations have low N, P, and K content and the soil is classified as acidic. The experimental design used was a split plot design with 3 replicates . The main plots were different grass species i.e. king grass (Pennisetum purpureum x P. typhoides and elephant grass (P. purpureum. The sub plots were the row spacing of gliricidia at 2, 3, 4, 6 m (1 hedgerows and 4 m (2 hedgerows. The results indicated that the growth and biomass production of grasses were significantly affected (P<0 .05 by the treatments in Bogor. The highest biomass productions was obtained from the 2 m row spacing which gave the highest dry matter production of grasses (1 .65 kg/hill and gliricidia (0 .086 kg/tree . In Sukabumi the growth and biomass production of grasses and gliricidia were also significantly affected by the treatments . The highest dry matter production was obtained with 2 m row spacing (dry matter of grasses and gliricidia were 1 .12 kg/hill and 0 .026 kg/tree, respectively . The result further indicated that biomass production of forages increased with the increase in gliricidia population. The alley cropping system wich is suitable for Bogor was the 2 m row spacing of gliricidia intercropped with either king or elephant grass and for Sukabumi 2 and 4 m (2 rows of gliricidia row spacing intercropped with king or elephant grass .

  12. Exotic Eucalyptus leaves are preferred over tougher native species but affect the growth and survival of shredders in an Atlantic Forest stream (Brazil).

    Science.gov (United States)

    Kiffer, Walace P; Mendes, Flavio; Casotti, Cinthia G; Costa, Larissa C; Moretti, Marcelo S

    2018-01-01

    We evaluated the effect of leaves of native and exotic tree species on the feeding activity and performance of the larvae of Triplectides gracilis, a typical caddisfly shredder in Atlantic Forest streams. Leaves of four native species that differ in chemistry and toughness (Hoffmannia dusenii, Miconia chartacea, Myrcia lineata and Styrax pohlii) and the exotic Eucalyptus globulus were used to determine food preferences and rates of consumption, production of fine particulate organic matter (FPOM), growth and survival of shredders. We hypothesized that the consumption rates of leaves of Eucalyptus and their effects on the growth and survival of shredders could be predicted by leaf chemistry and toughness. The larvae preferred to feed on soft leaves (H. dusenii and M. chartacea) independently of the content of nutrients (N and P) and secondary compounds (total phenolics). When such leaves were absent, they preferred E. globulus and did not consume the tough leaves (M. lineata and S. pohlii). In monodietary experiments, leaf consumption and FPOM production differed among the studied leaves, and the values observed for the E. globulus treatments were intermediate between the soft and tough leaves. The larvae that fed on H. dusenii and M. chartacea grew constantly over five weeks, while those that fed on E. globulus lost biomass. Larval survival was higher on leaves of H. dusenii, M. chartacea and S. pohlii than on E. globulus and M. lineata leaves. Although E. globulus was preferred over tougher leaves, long-term consumption of leaves of the exotic species may affect the abundance of T. gracilis in the studied stream. Additionally, our results suggest that leaf toughness can be a determining factor for the behavior of shredders where low-quality leaves are abundant, as in several tropical streams.

  13. Phenology and species determine growing-season albedo increase at the altitudinal limit of shrub growth in the sub-Arctic.

    Science.gov (United States)

    Williamson, Scott N; Barrio, Isabel C; Hik, David S; Gamon, John A

    2016-11-01

    Arctic warming is resulting in reduced snow cover and increased shrub growth, both of which have been associated with altered land surface-atmospheric feedback processes involving sensible heat flux, ground heat flux and biogeochemical cycling. Using field measurements, we show that two common Arctic shrub species (Betula glandulosa and Salix pulchra), which are largely responsible for shrub encroachment in tundra, differed markedly in albedo and that albedo of both species increased as growing season progressed when measured at their altitudinal limit. A moveable apparatus was used to repeatedly measure albedo at six precise spots during the summer of 2012, and resampled in 2013. Contrary to the generally accepted view of shrub-covered areas having low albedo in tundra, full-canopy prostrate B. glandulosa had almost the highest albedo of all surfaces measured during the peak of the growing season. The higher midsummer albedo is also evident in localized MODIS albedo aggregated from 2000 to 2013, which displays a similar increase in growing-season albedo. Using our field measurements, we show the ensemble summer increase in tundra albedo counteracts the generalized effect of earlier spring snow melt on surface energy balance by approximately 40%. This summer increase in albedo, when viewed in absolute values, is as large as the difference between the forest and tundra transition. These results indicate that near future (albedo related to Arctic vegetation change are unlikely to be particularly large and might constitute a negative feedback to climate warming in certain circumstances. Future efforts to calculate energy budgets and a sensible heating feedback in the Arctic will require more detailed information about the relative abundance of different ground cover types, particularly shrub species and their respective growth forms and phenology. © 2016 John Wiley & Sons Ltd.

  14. Exotic Eucalyptus leaves are preferred over tougher native species but affect the growth and survival of shredders in an Atlantic Forest stream (Brazil.

    Directory of Open Access Journals (Sweden)

    Walace P Kiffer

    Full Text Available We evaluated the effect of leaves of native and exotic tree species on the feeding activity and performance of the larvae of Triplectides gracilis, a typical caddisfly shredder in Atlantic Forest streams. Leaves of four native species that differ in chemistry and toughness (Hoffmannia dusenii, Miconia chartacea, Myrcia lineata and Styrax pohlii and the exotic Eucalyptus globulus were used to determine food preferences and rates of consumption, production of fine particulate organic matter (FPOM, growth and survival of shredders. We hypothesized that the consumption rates of leaves of Eucalyptus and their effects on the growth and survival of shredders could be predicted by leaf chemistry and toughness. The larvae preferred to feed on soft leaves (H. dusenii and M. chartacea independently of the content of nutrients (N and P and secondary compounds (total phenolics. When such leaves were absent, they preferred E. globulus and did not consume the tough leaves (M. lineata and S. pohlii. In monodietary experiments, leaf consumption and FPOM production differed among the studied leaves, and the values observed for the E. globulus treatments were intermediate between the soft and tough leaves. The larvae that fed on H. dusenii and M. chartacea grew constantly over five weeks, while those that fed on E. globulus lost biomass. Larval survival was higher on leaves of H. dusenii, M. chartacea and S. pohlii than on E. globulus and M. lineata leaves. Although E. globulus was preferred over tougher leaves, long-term consumption of leaves of the exotic species may affect the abundance of T. gracilis in the studied stream. Additionally, our results suggest that leaf toughness can be a determining factor for the behavior of shredders where low-quality leaves are abundant, as in several tropical streams.

  15. A comparative study on the effect of gamma-irradiation on growth and biomass yield in certain fuel-wood species

    International Nuclear Information System (INIS)

    Bandyopadhyay, B.; Nandy, A.K.; Mallick, R.; Chatterjee, A.

    1990-01-01

    A trial was conducted to study a comparative effect of gamma-radiation on the growth behaviour vis-a-vis biomass yield of Acacia nilotica Delite, Leucaena leucocephala (Lam) De Wit and Prosopis chilensis D.C (sub-family Mimosoidae). Dry seeds were exposed to 1, 2, 4, 8 and 16 KR doses of gammaradiation. Irradiat ed seeds were sown in the field along with the control. In case of L. leucocephala the growth of the plants as well as total biomass production increased steadily with increasing doses of irradiation upto 8 KR. In A. nilotica the response was similar to that of L leucocephala, but in this case maximum growth and biomass yield was obtained after 4 KR. On the other hand, P. chilensis did not exhibit a positive response to gammaradiation. Karyotype of the three species was also done. All these observations indicate the greater possibility of the utilization of gammaradiation in increasing biomass production. (author). 12 refs., 2 tabs., 7 figs

  16. Native plant growth promoting bacteria Bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in Lavandula dentata plants.

    Science.gov (United States)

    Armada, E; Probanza, A; Roldán, A; Azcón, R

    2016-03-15

    This study evaluates the responses of Lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (AM) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native Bacillus thuringiensis (endophytic bacteria). These microorganisms were drought tolerant and in general, increased plant growth and nutrition. Particularly, the AM fungal mixture and B. thuringiensis maximized plant biomass and compensated drought stress as values of antioxidant activities [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase APX)] shown. The AMF-bacteria interactions highly reduced the plant oxidative damage of lipids [malondialdehyde (MDA)] and increased the mycorrhizal development (mainly arbuscular formation representative of symbiotic functionality). These microbial interactions explain the highest potential of dually inoculated plants to tolerate drought stress. B. thuringiensis "in vitro" under osmotic stress does not reduce its PGPB (plant growth promoting bacteria) abilities as indole acetic acid (IAA) and ACC deaminase production and phosphate solubilization indicating its capacity to improve plant growth under stress conditions. Each one of the autochthonous fungal strains maintained their particular interaction with B. thuringiensis reflecting the diversity, intrinsic abilities and inherent compatibility of these microorganisms. In general, autochthonous AM fungal species and particularly their mixture with B. thuringiensis demonstrated their potential for protecting plants against drought and helping plants to thrive in semiarid ecosystems. Copyright © 2015 Elsevier GmbH. All rights reserved.

  17. A new in vitro method to detect growth and ochratoxin A-producing ability of multiple fungal species commonly found in food commodities.

    Science.gov (United States)

    Abarca, M L; Bragulat, M R; Cabañes, F J

    2014-12-01

    The aim of the study was to develop a new screening method to detect growth and ochratoxin A (OTA) production by multiple fungi growing in a small quantity of culture media, using microtiter plates. Eight ochratoxigenic species were included in the study. The strains were inoculated in sterile 96-well flat-bottom microtiter plates containing Yeast Extract Sucrose broth and Czapek Yeast Extract broth and incubated at 25 °C. Growth was daily monitored by absorbance measurements for 4 days and extended to 7 and 10 days for Penicillium spp. The entire experiment was repeated twice on different days. On each sampling time, five of the seven replicate wells inoculated for each strain and culture media were randomly selected and the content of each well was removed, extracted and injected into the HPLC. No statistically significant differences were observed for absorbance and OTA values, neither between replicates nor between experiments. Quantifiable OTA levels were detected after 48 h of incubation in Aspergillus alliaceus, Aspergillus carbonarius and Aspergillus niger, after 72 h in Aspergillus flocculosus, Aspergillus steynii and Aspergillus westerdijkiae and after 7 days in Penicillium nordicum and Penicillium verrucosum. The method offers the necessary tools for a rapid detection of growth and OTA production avoiding the use of plate cultures and can be very useful when many fungal isolates need to be screened. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Evaluation of Two Standard and Two Chromogenic Selective Media for Optimal Growth and Enumeration of Isolates of 16 Unique Bacillus Species.

    Science.gov (United States)

    Kabir, M Shahjahan; Hsieh, Ying-Hsin; Simpson, Steven; Kerdahi, Khalil; Sulaiman, Irshad M

    2017-06-01

    The genus Bacillus is a group of gram-positive endospore-forming bacteria that can cause food poisoning and diarrheal illness in humans. A wide range of food products have been linked to foodborne outbreaks associated with these opportunistic pathogens. The U.S. Food and Drug Administration recommends (in their Bacteriological Analytical Manual) the use of Bacara or mannitol egg yolk polymyxin (MYP) agar plates and the most-probable-number (MPN) method for enumeration and confirmation of Bacillus cereus and related species isolated from foods, sporadic cases, outbreaks, and routine environmental surveillance samples. We performed a comparative analysis of two chromogenic media (Bacara and Brilliance) and two traditional media (MYP and polymyxin egg yolk mannitol bromothymol blue agar [PEMBA]) for the isolation and enumeration of 16 Bacillus species under modified growth conditions that included pH, temperature, and dilution factor. A total of 50 environmental, food, and American Type Culture Collection reference isolates from 16 distinct Bacillus species were evaluated. A food adulteration experiment also was carried out by artificially adulterating two baby food matrices with two isolates each of B. cereus and Bacillus thuringiensis . Our results clearly indicated that chromogenic plating media (Bacara and Brilliance) are better than conventional standard media (MYP and PEMBA) for the detection and enumeration of B. cereus in foods and other official regulatory samples. The comparison of the two chromogenic media also indicated that Brilliance medium to be more efficient and selective for the isolation of Bacillus.

  19. In ovo 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure in three avian species. 1. Effects on thyroid hormones and growth during the perinatal period.

    Science.gov (United States)

    Janz, D M; Bellward, G D

    1996-08-01

    Thyroid hormones are important in the perinatal growth and development of avian species, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds have been shown to cause alterations in these hormones in laboratory animals. Since the decreased reproductive success in certain fish-eating bird populations exposed to TCDD and related compounds is characterized by high embryo and hatchling mortality, we examined the effects of in ovo TCDD exposure on plasma thyroid hormone concentrations (total T3, total T4) and body and skeletal growth during the perinatal period in the domestic chicken (Gallus gallus), domestic pigeon (Columba livia), and great blue heron (Ardea herodias). Hepatic ethoxyresorufin O-deethylase (EROD) activity was also determined as an enzymatic marker of cytochrome P450IA induction by TCDD. [3H]TCDD was injected into the air cell of chicken eggs (21-day incubation period) on Embryonic Day 4.5 (0.1 microgram/kg egg), pigeon eggs (18-day incubation period) on Embryonic Day 3.5 (1 microgram/kg egg) and Embryonic Day 14 (3 microgram/kg egg), and heron eggs (28-day incubation period) at approximately the midpoint of incubation (2 microgram/kg egg). Chickens were euthanized on Embryonic Days 17 and 19, day of hatch (Embryonic Day 21), and Days 2 and 4 after hatch. Pigeons and herons were euthanized either at hatch (Embryonic Days 18 and 28, respectively), or fed an uncontaminated diet for 7 days prior to sacrifice. Although hepatic EROD activity was induced 13- to 43-fold above controls in chickens, there was no effect of TCDD exposure on hatchability, body growth, subcutaneous edema, or plasma thyroid hormone levels. In pigeons exposed to TCDD on Embryonic Day 3.5, EROD was induced 6- to 15-fold, hatchability was decreased, liver to body weight ratio was elevated, and body and skeletal growth were decreased (p chickens, pigeons, and great blue herons.

  20. GENERAL: Kinetic Behaviors of Catalysis-Driven Growth of Three-Species Aggregates on Base of Exchange-Driven Aggregations

    Science.gov (United States)

    Sun, Yun-Fei; Chen, Dan; Lin, Zhen-Quan; Ke, Jian-Hong

    2009-06-01

    We propose a solvable aggregation model to mimic the evolution of population A, asset B, and the quantifiable resource C in a society. In this system, the population and asset aggregates themselves grow through self-exchanges with the rate kernels K1(k, j) = K1kj and K2(k, j) = K2kj, respectively. The actions of the population and asset aggregations on the aggregation evolution of resource aggregates are described by the population-catalyzed monomer death of resource aggregates and asset-catalyzed monomer birth of resource aggregates with the rate kernels J1(k, j) = J1k and J2(k, j) = J2k, respectively. Meanwhile, the asset and resource aggregates conjunctly catalyze the monomer birth of population aggregates with the rate kernel I1(k, i, j) = I1kiμjη, and population and resource aggregates conjunctly catalyze the monomer birth of asset aggregates with the rate kernel I2(k, i, j) = I2kivjη. The kinetic behaviors of species A, B, and C are investigated by means of the mean-field rate equation approach. The effects of the population-catalyzed death and asset-catalyzed birth on the evolution of resource aggregates based on the self-exchanges of population and asset appear in effective forms. The coefficients of the effective population-catalyzed death and the asset-catalyzed birth are expressed as J1e = J1/K1 and J2e = J2/K2, respectively. The aggregate size distribution of C species is found to be crucially dominated by the competition between the effective death and the effective birth. It satisfies the conventional scaling form, generalized scaling form, and modified scaling form in the cases of J1e J2e, respectively. Meanwhile, we also find the aggregate size distributions of populations and assets both fall into two distinct categories for different parameters μ, ν, and η: (i) When μ = ν = η = 0 and μ = ν = 0, η = 1, the population and asset aggregates obey the generalized scaling forms; and (ii) When μ = ν = 1, η = 0, and μ = ν = η = 1, the

  1. Evaluating the accuracy of genomic prediction of growth and wood traits in two Eucalyptus species and their F1hybrids.

    Science.gov (United States)

    Tan, Biyue; Grattapaglia, Dario; Martins, Gustavo Salgado; Ferreira, Karina Zamprogno; Sundberg, Björn; Ingvarsson, Pär K

    2017-06-29

    Genomic prediction is a genomics assisted breeding methodology that can increase genetic gains by accelerating the breeding cycle and potentially improving the accuracy of breeding values. In this study, we use 41,304 informative SNPs genotyped in a Eucalyptus breeding population involving 90 E.grandis and 78 E.urophylla parents and their 949 F 1 hybrids to develop genomic prediction models for eight phenotypic traits - basic density and pulp yield, circumference at breast height and height and tree volume scored at age three and six years. We assessed the impact of different genomic prediction methods, the composition and size of the training and validation set and the number and genomic location of SNPs on the predictive ability (PA). Heritabilities estimated using the realized genomic relationship matrix (GRM) were considerably higher than estimates based on the expected pedigree, mainly due to inconsistencies in the expected pedigree that were readily corrected by the GRM. Moreover, the GRM more precisely capture Mendelian sampling among related individuals, such that the genetic covariance was based on the true proportion of the genome shared between individuals. PA improved considerably when increasing the size of the training set and by enhancing relatedness to the validation set. Prediction models trained on pure species parents could not predict well in F 1 hybrids, indicating that model training has to be carried out in hybrid populations if one is to predict in hybrid selection candidates. The different genomic prediction methods provided similar results for all traits, therefore either GBLUP or rrBLUP represents better compromises between computational time and prediction efficiency. Only slight improvement was observed in PA when more than 5000 SNPs were used for all traits. Using SNPs in intergenic regions provided slightly better PA than using SNPs sampled exclusively in genic regions. The size and composition of the training set and number of SNPs

  2. Gas exchange and growth responses to nutrient enrichment in invasive Glyceria maxima and native New Zealand Carex species

    DEFF Research Database (Denmark)

    Sorrell, Brian Keith; Brix, Hans; Fitridge, Isla

    2012-01-01

    the sedges, but correlations between leaf N, gas exchange parameters (Amaxa, Amaxm, Rd and gs) and RGR were all highly significant in G. maxima, whereas they were weak or absent in the sedges. Allocation of biomass (root:shoot ratio, leaf mass ratio, root mass ratio), plant N and P content, and allocation......) in G. maxima (17 ± 6 m2 kg-1) was 1.3 times that of the sedges, leading to 1.4 times higher maximum rates of photosynthesis (350 – 400 nmol CO2 g-1 dry mass s-1) expressed on a leaf mass basis (Amaxm) when N supply was unlimited, compared to the sedges (mass s-1). Analysis......, the sedges had 2.4 times higher intrinsic water use efficiency (A/gs: range 20-70 c.f. 8-30 µmol CO2 mol-1 H2O) and 1.6 times higher nitrogen use efficiency (NUE: 25 – 30 c.f. 20 – 23 g dry mass g-1 N) under excess N supply. Relative growth rates (RGR) were not significantly higher in G. maxima than...

  3. A new class of quorum quenching molecules from Staphylococcus species affects communication and growth of gram-negative bacteria.

    Directory of Open Access Journals (Sweden)

    Ya-Yun Chu

    Full Text Available The knowledge that many pathogens rely on cell-to-cell communication mechanisms known as quorum sensing, opens a new disease control strategy: quorum quenching. Here we report on one of the rare examples where Gram-positive bacteria, the 'Staphylococcus intermedius group' of zoonotic pathogens, excrete two compounds in millimolar concentrations that suppress the quorum sensing signaling and inhibit the growth of a broad spectrum of Gram-negative beta- and gamma-proteobacteria. These compounds were isolated from Staphylococcus delphini. They represent a new class of quorum quenchers with the chemical formula N-[2-(1H-indol-3-ylethyl]-urea and N-(2-phenethyl-urea, which we named yayurea A and B, respectively. In vitro studies with the N-acyl homoserine lactone (AHL responding receptor LuxN of V. harveyi indicated that both compounds caused opposite effects on phosphorylation to those caused by AHL. This explains the quorum quenching activity. Staphylococcal strains producing yayurea A and B clearly benefit from an increased competitiveness in a mixed community.

  4. Classification of images of wheat, ryegrass and brome grass species at early growth stages using principal component analysis

    Directory of Open Access Journals (Sweden)

    Golzarian Mahmood R

    2011-09-01

    Full Text Available Abstract Wheat is one of the most important crops in Australia, and the identification of young plants is an important step towards developing an automated system for monitoring crop establishment and also for differentiating crop from weeds. In this paper, a framework to differentiate early narrow-leaf wheat from two common weeds from their digital images is developed. A combination of colour, texture and shape features is used. These features are reduced to three descriptors using Principal Component Analysis. The three components provide an effective and significant means for distinguishing the three grasses. Further analysis enables threshold levels to be set for the discrimination of the plant species. The PCA model was evaluated on an independent data set of plants and the results show accuracy of 88% and 85% in the differentiation of ryegrass and brome grass from wheat, respectively. The outcomes of this study can be integrated into new knowledge in developing computer vision systems used in automated weed management.

  5. Effects of ultraviolet-B radiation (UV-B) on growth and physiology of the dune grassland species Calamagrostis epigeios

    International Nuclear Information System (INIS)

    Tosserams, M.; Rozema, J.

    1995-01-01

    Seedlings of Calamagrostis epigeios were exposed to four levels of UV-B radiation (280-320 nm), simulating up to 44% reduction of stratospheric ozone concentration during summertime in The Netherlands, to determine the response of this plant species to UV-B irradiation. After six weeks of UV-B treatment, total biomass of all UV-B treated plants was higher, compared to plants that had received no UV-B radiation. The increase of biomass did not appear to be the result of a stimulation of net photosynthesis. Also, transpiration rate and water use efficiency were not altered by UV-B at any exposure level. Pigment analysis of leaf extracts showed no effect of enhanced UV-B radiation on chlorophyll content and accumulation of UV absorbing pigments. UV-B irradiance, however, did reduce the transmittance of visible light (400-700 nm) of intact attached leaves, suggesting a change in anatomical characteristics of the leaves. Additionally, the importance of including an ambient UV-B treatment in indoor experiments is discussed

  6. Effect of epidermal growth factor on the labeling of the various RNA species and of nuclear proteins in primary rat astroglial cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Avola, R.; Condorelli, D.F.; Turpeenoja, L.; Ingrao, F.; Reale, S.; Ragusa, N.; Giuffrida Stella, A.M.

    1988-05-01

    This study investigated the effects of epidermal growth factor (EGF) on the labeling of various RNA species and of nuclear proteins in primary rat astroglial cell cultures. After 12 hours of EGF treatment in serum-free medium or chemically defined medium, significant increase in RNA labeling, and also in acid-soluble radioactivity and RNA content, was observed. The ratio RNA/DNA was significantly higher in EGF-treated cultures compared with controls. Ribosomal RNAs (28S and 18S), polyadenylated, and nonpolyadenylated RNAs showed a higher specific radioactivity in EGF-treated cultures. Among the nuclear proteins, the labeling of basic proteins was enhanced by EGF treatment, whereas that of total nuclear acidic protein (NHPs) was less modified, except for some NHPs separated by gel electrophoresis with a molecular weight (MW) approximately 95-83 and 44 kd, which were significantly more labeled in EGF-treated cultures.

  7. Effects of soil type and light on height growth, biomass partitioning, and nitrogen dynamics on 22 species of tropical dry forest tree seedlings: Comparisons between legumes and nonlegumes.

    Science.gov (United States)

    Smith-Martin, Christina M; Gei, Maria G; Bergstrom, Ellie; Becklund, Kristen K; Becknell, Justin M; Waring, Bonnie G; Werden, Leland K; Powers, Jennifer S

    2017-03-01

    The seedling stage is particularly vulnerable to resource limitation, with potential consequences for community composition. We investigated how light and soil variation affected early growth, biomass partitioning, morphology, and physiology of 22 tree species common in tropical dry forest, including eight legumes. Our hypothesis was that legume seedlings are better at taking advantage of increased resource availability, which contributes to their successful regeneration in tropical dry forests. We grew seedlings in a full-factorial design under two light levels in two soil types that differed in nutrient concentrations and soil moisture. We measured height biweekly and, at final harvest, biomass partitioning, internode segments, leaf carbon, nitrogen, δ 13 C, and δ 15 N. Legumes initially grew taller and maintained that height advantage over time under all experimental conditions. Legumes also had the highest final total biomass and water-use efficiency in the high-light and high-resource soil. For nitrogen-fixing legumes, the amount of nitrogen derived from fixation was highest in the richer soil. Although seed mass tended to be larger in legumes, seed size alone did not account for all the differences between legumes and nonlegumes. Both belowground and aboveground resources were limiting to early seedling growth and function. Legumes may have a different regeneration niche, in that they germinate rapidly and grow taller than other species immediately after germination, maximizing their performance when light and belowground resources are readily available, and potentially permitting them to take advantage of high light, nutrient, and water availability at the beginning of the wet season. © 2017 Botanical Society of America.

  8. The in vitro effect of selected essential oils on the growth and mycotoxin production of Aspergillus species.

    Science.gov (United States)

    Císarová, Miroslava; Tančinová, Dana; Medo, Juraj; Kačániová, Miroslava

    2016-10-02

    The aim of the present study was to assess the antifungal and anti-toxinogenic activity of 15 essential oils (EOs) against three fungi of the genus Aspergillus (A. parasiticus KMi-227-LR, A. parasiticus KMi-220-LR and A. flavus KMi-202-LR). The minimum inhibitory doses (MIDs) of the tested essential oils and their antifungal activity were determined using the micro-atmosphere method. The original commercial essential oil samples of Jasminum officinale L., Thymus vulgaris L., Syzygium aromaticum (L.) Merrill & Perry, Rosmarinus officinalis L., Ocimum basilicum L., Eucalyptus globulus Labill., Salvia officinalis L., Citrus limon (L.) Burm, Origanum vulgare L., Lavandula angustifolia Mill., Carum carvi L., Citrus sinensis (L.) Osbeck., Zingiber officinalis Rosc., Mentha piperita L. and Cinnamomum zeylanicum Nees. (C. verum J.S.Presl.) were produced in Slovakia (Calendula a.s., Nová Ľubovňa, Slovakia). All essential oils exhibited activity against all tested strains of fungi. After 14 days of incubation, A. flavus (KMi-202-LR) showed the highest susceptibility with a growth inhibition percentage (GIP) of 18.70% to C. limon and 5.92% to C. sinensis, while A. parasiticus (KMi-220-LR) exhibited a GIP of 20.56% to J. officinale. The minimum inhibitory doses (MIDs) of EOs with the most significant activity were recorded. The best antifungal activity, using the micro-atmosphere method was found in S. aromaticum with an MID of 62.5 μL L -1 air, T. vulgaris (MID of 62.5 μL L -1 air) and O. vulgare (MID of 31.5 μL L -1 air) against all tested strains. Mycotoxin production of the tested strains was evaluated by the thin layer chromatography (TLC) method. Mycotoxin production of AFB 1 and AFG 1 was inhibited following all treatments with C. carvi, R. officinale and S. officinale, Eucalyptus globulus L. and O. basilicum L. Essential oils exhibited a potential inhibition activity against toxic fungi, although, these affected only the production of AFB 1 .

  9. Effect of dietary supplementation of vitamin C on growth, reactive oxygen species, and antioxidant enzyme activity of Apostichopus japonicus (Selenka) juveniles exposed to nitrite

    Science.gov (United States)

    Luo, Zuoyong; Wang, Baojie; Liu, Mei; Jiang, Keyong; Liu, Mingxing; Wang, Lei

    2014-07-01

    Different amounts of vitamin C were added to diets fed to juveniles (2.5 ± 0.15 g) of sea cucumber Apostichopus japonic u s (Selenka) in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels (0.5, 1.0, and 1.5 mg/L) of nitrite stress for 4, 8, and 12 h at four time intervals (0, 15, 30, and 45 d). Growth of the animals was recorded during the experiment. Reactive oxygen species (ROS) (i.e. hydroxyl free radical (-OH), malondialdehyde (MDA) and total antioxidant capacity (T-AOC)) and antioxidant enzyme activities (i.e., superoxide dismutase (SOD) and catalase (CAT)) were measured. Response surface methodology (RSM) was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain (WG) and special growth rate (SGR) of vitamin C supplementation groups were significantly higher than those of control group ( P effectively the effects of nitrite exposure.

  10. Effects of time, temperature, and storage container on the growth of Fusarium species: implications for the worldwide Fusarium keratitis epidemic of 2004-2006.

    Science.gov (United States)

    Bullock, John D; Elder, B Laurel; Khamis, Harry J; Warwar, Ronald E

    2011-02-01

    To demonstrate the effects of time, temperature, and container properties on the ability of ReNu with MoistureLoc (ReNuML; contains the antimicrobial agent alexidine) to inhibit growth of Fusarium species. ReNu with MoistureLoc was stored in its Bausch & Lomb (Rochester, New York) plastic or similarly sized glass containers for 1 and 4 weeks at room temperature, 42°C, and 56°C, and then tested for its ability to inhibit growth of 7 Fusarium isolates. ReNu with MoistureLoc stored in glass containers for 1 or 4 weeks at all 3 temperatures demonstrated no significant fungistatic deterioration. However, ReNuML stored at 56°C in its Bausch & Lomb plastic container demonstrated a statistically significant fungistatic deterioration compared with room temperature storage in its original plastic container or with glass container storage at any temperature. When exposed to elevated storage temperature, it appears that an interaction between ReNuML and its Bausch & Lomb plastic container adversely affects the fungistatic properties of ReNuML, which could have contributed to the Fusarium keratitis epidemic of 2004 through 2006.

  11. Effects of pH on biomass, maximum specific growth rate and extracellular enzyme production by three species of cutaneous propionibacteria grown in continuous culture.

    Science.gov (United States)

    Greenman, J; Holland, K T; Cunliffe, W J

    1983-05-01

    Three cutaneous propionibacteria, Propionibacterium acnes, Propionibacterium avidum and Propionibacterium granulosum, were grown in chemostats using semi-synthetic medium at various pH values. Growth occurred between pH 4.5 and 7.5 for P. acnes and pH 5.0 and 8.0 for P. avidum and P. granulosum. The highest mumax was at pH 6.0 for the three species. Maximum biomass production was obtained at pH 6.0 for P. acnes and P. avidum and at pH 7.5 for P. granulosum. Extracellular enzyme production occurred over the entire pH growth range when denaturation of the enzymes was taken into account. However, detectable activity of the enzymes was found in a narrower range of pH due to the denaturation of the enzymes at low or high pH values. The highest production of enzymes occurred at pH values between 5.0 and 6.0, apart from the production of hyaluronate lyase of P. granulosum (pH 6.0 to 7.0) and the proteinase of P. acnes and P. avidum (pH 5.0 to 7.5). Propionibacterium acnes produced a lipase, hyaluronate lyase, phosphatase and proteinase activity. Propionibacterium avidum produced a lipase and proteinase activity. Propionibacterium granulosum produced a lipase and hyaluronate lyase.

  12. Preliminarily study on the maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on gastropods

    Science.gov (United States)

    Zhu, Tingbing; Zhang, Lihong; Zhang, Tanglin; Wang, Yaping; Hu, Wei; Olsen, Rolf Eric; Zhu, Zuoyan

    2017-10-01

    The present study preliminarily examined the differences in maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on four gastropods species (Bellamya aeruginosa, Radix auricularia, Parafossarulus sinensis and Alocinma longicornis) under laboratory conditions. In the maximum handling size trial, five fish from each age group (1-year-old and 2-year-old) and each genotype (transgenic and non-transgenic) of common carp were individually allowed to feed on B. aeruginosa with wide shell height range. The results showed that maximum handling size increased linearly with fish length, and there was no significant difference in maximum handling size between the two genotypes. In the size selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on three size groups of B. aeruginosa. The results show that the two genotypes of C. carpio favored the small-sized group over the large-sized group. In the species selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on thin-shelled B. aeruginosa and thick-shelled R. auricularia, and five pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on two gastropods species (P. sinensis and A. longicornis) with similar size and shell strength. The results showed that both genotypes preferred thin-shelled Radix auricularia rather than thick-shelled B. aeruginosa, but there were no significant difference in selectivity between the two genotypes when fed on P. sinensis and A. longicornis. The present study indicates that transgenic and non-transgenic C. carpio show similar selectivity of predation on the size- and species-limited gastropods. While this information may be useful for assessing the environmental risk of transgenic carp, it does not necessarily demonstrate that transgenic common carp might

  13. Photosynthesis acclimation, leaf nitrogen concentration, and growth of four tree species over 3 years in response to elevated carbon dioxide and nitrogen treatment in subtropical China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juxiu; Zhou, Guoyi; Duan, Honglang; Li, Yuelin; Zhang, Deqiang [Chinese Academy of Sciences, Guangzhou (China). South China Botanical Garden; Xu, Zhihong [Griffith Univ., Nathan, Brisbane (Australia). Centre for Forestry and Horticultural Research

    2011-10-15

    Up to date, most studies about the plant photosynthetic acclimation responses to elevated carbon dioxide (CO{sub 2}) concentration have been performed in temperate areas, which are often N limited under natural conditions and with low ambient N deposition. It is unclear whether photosynthetic downregulation is alleviated with increased N availability, for example, from increased N deposition due to fossil fuel combustion in the tropics and subtropics. Awareness of plant photosynthetic responses to elevated CO{sub 2} concentration will contribute to the better understanding and prediction of future forest productivity under global change. Four tree species, Schima superba Gardn. et Champ., Ormosia pinnata (Lour.) Merr, Castanopsis hystrix AC. DC., and Acmena acuminatissima (Blume) Merr. et Perry were exposed to a factorial combination of atmospheric CO{sub 2} concentration (ambient and elevated CO{sub 2} concentration at ca. 700 {mu}mol CO{sub 2} mol{sup -1}) and N deposition (ambient and ambient + 100 kg N ha{sup -1} year{sup -1}) in open-top chambers in southern China for 3 years since March 2005. Light-saturated net photosynthetic rate, leaf N concentration, and tree growth of all species were measured. The CO{sub 2} treatments did not affect light-saturated net photosynthetic rate of all species grown with the high N treatment. However, S. superba grown with the low N treatment (ambient) had 23% and 47% greater net photosynthesis in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for December 2006 and November 2007 (20 and 31 months after the treatments were applied), respectively, and A. acuminatissima grown with the low N treatment had 173%, 26%, and 121% greater net photosynthesis in trees grown in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for July 2006 (16 months after the treatments), December 2006 (20 months), and November 2007 (31 months), respectively, whereas

  14. RETADD-II: a long-range atmospheric trajectory model with consistent treatment of deposition loss and species growth and decay

    International Nuclear Information System (INIS)

    Murphy, B.D.; Ohr, S.Y.; Begovich, C.L.

    1984-08-01

    A versatile model is described which estimates long-range atmospheric dispersion based on plume trajectories. This model allows the treatment of the dispersal from a source at an arbitrary height while taking account of plume depletion by dry and wet deposition together with the decay of material to successor species. The plume depletion, decay and growth equations are solved in an efficient manner which can accommodate up to eight pollutants (i.e., a parent and seven serial decay products). The code is particularly suitable for applications involving radioactive chain decay or for cases involving chemical species with successor decay products. Arbitrary emission rates can be specified for the members of the chain or, as is commonly the case, a sole emission rate can be specified for the first member. The code uses readily available upper-air wind data for the North American continent and it is therefore intended for the estimation of regional or continental scale dispersion patterns. This code is one of a group of codes, the Computerized Radiological Risk Investigation System (Baes and Miller, 1981), designed to simulate the transport of radionuclides through environmental pathways. 24 references, 5 figures

  15. Extracts of three Laserpitium L. species and their principal components laserpitine and sesquiterpene lactones inhibit microbial growth and biofilm formation by oral Candida isolates.

    Science.gov (United States)

    Popović, Višnja; Stojković, Dejan; Nikolić, Miloš; Heyerick, Arne; Petrović, Silvana; Soković, Marina; Niketić, Marjan

    2015-04-01

    Antimicrobial properties of extracts of underground parts of three Laserpitium L. (Apiaceae) species, namely Laserpitium latifolium L., Laserpitium zernyi Hayek and Laserpitium ochridanum Micevski, were investigated. The investigated species are widely used as functional foods, as spices and for preparations in traditional medicine for treating complaints connected with infection and inflammation. Furthermore, antimicrobial and antibiofilm effects of laserpitine, the most abundant compound in the chloroform extract of L. latifolium, and guaianolide sesquiterpene lactones, such as, isomontanolide, montanolide and tarolide, principal components of the extracts of L. zernyi and L. ochridanum were assessed. The antimicrobial activity was tested using the microdilution method against five pathogenic bacteria and five fungi, as well as in the microplate biofilm assay on two Candida clinical isolates (C. albicans and C. krusei). Among the extracts, L. latifolium showed the most prominent activity. Isolated metabolites exerted higher effects against fungal than against bacterial strains, isomontanolide being the most active. Interestingly, all constituents showed higher potential on inhibition of biofilm formation than fluconazole, a reference compound. Tested metabolites may be good novel agents with high antifungal and antibacterial potential that might find practical applications in food industry as food preservatives in order to retard the growth of food spoiling microbes, but only after detailed safety assessments.

  16. [Difference of anti-fracture mechanical characteristics between lateral-root branches and adjacent upper straight roots of four plant species in vigorous growth period].

    Science.gov (United States)

    Liu, Peng-fei; Liu, Jing; Zhu, Hong-hui; Zhang, Xin; Zhang, Ge; Li, You-fang; Su, Yu; Wang, Chen-jia

    2016-01-01

    Taking four plant species, Caragana korshinskii, Salix psammophila, Hippophae rhamnides and Artemisia sphaerocephala, which were 3-4 years old and in vigorous growth period, as test materials, the anti-fracture forces of lateral-root branches and adjacent upper straight roots were measured with the self-made fixture and the instrument of TY 8000. The lateral-root branches were vital and the diameters were 1-4 mm. The results showed that the anti-fracture force and anti-fracture strength of lateral-root branches were lesser than those of the adjacent upper straight roots even though the average diameter of lateral-root branches was greater. The ratios of anti-fracture strength of lateral-root branches to the adjacent upper straight roots were 71.5% for C. korshinskii, 62.9% for S. psammophila, 45.4% for H. rhamnides and 35.4% for A. sphaerocephala. For the four plants, the anti-fracture force positively correlated with the diameter in a power function, while the anti-fracture strength negatively correlated with diameter in a power function. The anti-fracture strengths of lateral-root branches and adjacent upper straight roots for the four species followed the sequence of C. korshinskii (33.66 and 47.06 MPa) > S. psammophila (17.31 and 27.54 MPa) > H. rhamnides (3.97 and 8.75 MPa) > A. sphaerphala (2.18 and 6.15 MPa).

  17. Invasion Potential of Two Tropical Physalis Species in Arid and Semi-Arid Climates: Effect of Water-Salinity Stress and Soil Types on Growth and Fecundity.

    Science.gov (United States)

    Ozaslan, Cumali; Farooq, Shahid; Onen, Huseyin; Bukun, Bekir; Ozcan, Selcuk; Gunal, Hikmet

    2016-01-01

    Invasive plants are recognized for their impressive abilities to withstand adverse environmental conditions however, all invaders do not express the similar abilities. Therefore, survival, growth, nutrient uptake and fecundity of two co-occurring, invasive Physalis species were tested under water and salinity stresses, and different soil textures in the current study. Five different water stress levels (100, 75, 50, 25, and 12.5% pot water contents), four different soil salinity levels (0, 3, 6, and 12 dSm-1) and four different soil textures (67% clay, 50% clay, silt clay loam and sandy loam) were included in three different pot experiments. Both weeds survived under all levels of water stress except 12.5% water contents and on all soil types however, behaved differently under increasing salinity. The weeds responded similarly to salinity up till 3 dSm-1 whereas, P. philadelphica survived for longer time than P. angulata under remaining salinity regimes. Water and salinity stress hampered the growth and fecundity of both weeds while, soil textures had slight effect. Both weeds preferred clay textured soils for better growth and nutrient uptake however, interactive effect of weeds and soil textures was non-significant. P. angulata accumulated higher K and Na while P. philadelphica accrued more Ca and Mg as well as maintained better K/Na ratio. P. angulata accumulated more Na and P under salinity stress while, P. philadelphica accrued higher K and Mg, and maintained higher K/Na ratio. Collectively, highest nutrient accumulation was observed under stress free conditions and on clay textured soils. P. philadelphica exhibited higher reproductive output under all experimental conditions than P. angulata. It is predicted that P. philadelphica will be more problematic under optimal water supply and high salinity while P. angulata can better adapt water limited environments. The results indicate that both weeds have considerable potential to further expand their ranges in

  18. Invasion Potential of Two Tropical Physalis Species in Arid and Semi-Arid Climates: Effect of Water-Salinity Stress and Soil Types on Growth and Fecundity

    Science.gov (United States)

    Ozaslan, Cumali; Bukun, Bekir; Ozcan, Selcuk

    2016-01-01

    Invasive plants are recognized for their impressive abilities to withstand adverse environmental conditions however, all invaders do not express the similar abilities. Therefore, survival, growth, nutrient uptake and fecundity of two co-occurring, invasive Physalis species were tested under water and salinity stresses, and different soil textures in the current study. Five different water stress levels (100, 75, 50, 25, and 12.5% pot water contents), four different soil salinity levels (0, 3, 6, and 12 dSm-1) and four different soil textures (67% clay, 50% clay, silt clay loam and sandy loam) were included in three different pot experiments. Both weeds survived under all levels of water stress except 12.5% water contents and on all soil types however, behaved differently under increasing salinity. The weeds responded similarly to salinity up till 3 dSm-1 whereas, P. philadelphica survived for longer time than P. angulata under remaining salinity regimes. Water and salinity stress hampered the growth and fecundity of both weeds while, soil textures had slight effect. Both weeds preferred clay textured soils for better growth and nutrient uptake however, interactive effect of weeds and soil textures was non-significant. P. angulata accumulated higher K and Na while P. philadelphica accrued more Ca and Mg as well as maintained better K/Na ratio. P. angulata accumulated more Na and P under salinity stress while, P. philadelphica accrued higher K and Mg, and maintained higher K/Na ratio. Collectively, highest nutrient accumulation was observed under stress free conditions and on clay textured soils. P. philadelphica exhibited higher reproductive output under all experimental conditions than P. angulata. It is predicted that P. philadelphica will be more problematic under optimal water supply and high salinity while P. angulata can better adapt water limited environments. The results indicate that both weeds have considerable potential to further expand their ranges in

  19. Invasion Potential of Two Tropical Physalis Species in Arid and Semi-Arid Climates: Effect of Water-Salinity Stress and Soil Types on Growth and Fecundity.

    Directory of Open Access Journals (Sweden)

    Cumali Ozaslan

    Full Text Available Invasive plants are recognized for their impressive abilities to withstand adverse environmental conditions however, all invaders do not express the similar abilities. Therefore, survival, growth, nutrient uptake and fecundity of two co-occurring, invasive Physalis species were tested under water and salinity stresses, and different soil textures in the current study. Five different water stress levels (100, 75, 50, 25, and 12.5% pot water contents, four different soil salinity levels (0, 3, 6, and 12 dSm-1 and four different soil textures (67% clay, 50% clay, silt clay loam and sandy loam were included in three different pot experiments. Both weeds survived under all levels of water stress except 12.5% water contents and on all soil types however, behaved differently under increasing salinity. The weeds responded similarly to salinity up till 3 dSm-1 whereas, P. philadelphica survived for longer time than P. angulata under remaining salinity regimes. Water and salinity stress hampered the growth and fecundity of both weeds while, soil textures had slight effect. Both weeds preferred clay textured soils for better growth and nutrient uptake however, interactive effect of weeds and soil textures was non-significant. P. angulata accumulated higher K and Na while P. philadelphica accrued more Ca and Mg as well as maintained better K/Na ratio. P. angulata accumulated more Na and P under salinity stress while, P. philadelphica accrued higher K and Mg, and maintained higher K/Na ratio. Collectively, highest nutrient accumulation was observed under stress free conditions and on clay textured soils. P. philadelphica exhibited higher reproductive output under all experimental conditions than P. angulata. It is predicted that P. philadelphica will be more problematic under optimal water supply and high salinity while P. angulata can better adapt water limited environments. The results indicate that both weeds have considerable potential to further expand

  20. N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species.

    Science.gov (United States)

    Li, Hong; Li, Mengchun; Luo, Jie; Cao, Xu; Qu, Long; Gai, Ying; Jiang, Xiangning; Liu, Tongxian; Bai, Hua; Janz, Dennis; Polle, Andrea; Peng, Changhui; Luo, Zhi-Bin

    2012-10-01

    To investigate how N-fertilization affects the growth, carbon and nitrogen (N) physiology, and wood properties of poplars with contrasting growth characteristics, slow-growing (Populus popularis, Pp) and fast-growing (P. alba×P. glandulosa, Pg) poplar saplings were exposed to different N levels. Above-ground biomass, leaf area, photosynthetic rates (A), instantaneous photosynthetic nitrogen use efficiency (PNUE (i)), chlorophyll and foliar sugar concentrations were higher in Pg than in Pp. Foliar nitrate reductase (NR) activities and root glutamate synthase (GOGAT) activities were higher in Pg than in Pp as were the N amount and NUE of new shoots. Lignin contents and calorific values of Pg wood were less than that of Pp wood. N-fertilization reduced root biomass of Pg more than of Pp, but increased leaf biomass, leaf area, A, and PNUE(i) of Pg more than of Pp. Among 13 genes involved in the transport of ammonium or nitrate or in N assimilation, transcripts showed more pronounced changes to N-fertilization in Pg than in Pp. Increases in NR activities and N contents due to N-fertilization were larger in Pg than in Pp. In both species, N-fertilization resulted in lower calorific values as well as shorter and wider vessel elements/fibres. These results suggest that growth, carbon and N physiology, and wood properties are more sensitive to increasing N availability in fast-growing poplars than in slow-growing ones, which is probably due to prioritized resource allocation to the leaves and accelerated N physiological processes in fast-growing poplars under higher N levels.

  1. Establishment, Growth and Biomass yield of three Grass species on a degraded Ultisol and their effect on soil loss.

    Directory of Open Access Journals (Sweden)

    2016-11-01

    Full Text Available Erosion is a cause for concern; this is because of its effects on the soil used for both agricultural and non-agricultural purposes. Experiments were carried out to check the establishment, growth and biomass field of 3 tropical plants and their effects on soil loss during 2007 planting season. The treatments comprised 3 grasses viz. Azonopus compressus. Panicum maximum and Andropogon gayanus. The grasses were laid our in the field using a randomized complete block design replicated 4 times. Bare soil was used as the control. The parameters tested were plant height, leaf area index, root density, root establishment and the amount of soil loss using erosion pins. The result showed that Andropogon gayanus has an edge over Panicum maximum and Axonopus compressus with reference to plant height, root establishment, root density and leaf area index. Andropogon gayanus had a higher plant height from 3,6,9 and 12WAP with plant heights of 3.30cm, 3.63cm,3.93cm and 4.30cm representing 15.7%, 19.3% and 28.8% respectively. It was followed by P. maximum while A. compressus maintained the lowest plant height from 3,6,9 and 12 WAP with plant height of 2.83cm, 3.05cm, 3.20cm and 3.45cm respectively. In terms of root density, A. compressus did not have much root density which was 0.02t/ha, also at 12WAP, P. maximum did not have much root density which was 0.06t/ha though it was higher than A. compressus. The trend was the same for A. gayanus whose root density was 0.75t/ha. In terms of leaf area index (LAI, it was shown that at 3WAP and 6WAP, A. compressus had the lowest leaf area index of 58.25 and 65.75 respectively. Also at 9WAP and 12WAP A. compressus had 72.28 and 75.08t/ha respectively. At 3WAP and 6WAP P.maximum had a high leaf area index of 66.60 and 77.25 respectively. A. gayanus at 3WAP and 6WAP had 87.73 gayanus at 3WAP and 6WAP had 87.73 and 90.80 for 9WAP and 12WAP respectively. A. compressus protected the soil, reducing soil loss as a total of 9

  2. Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda Crescimento das espécies de capim-colchão Digitaria ciliaris e Digitaria nuda

    Directory of Open Access Journals (Sweden)

    R.C. Souza

    2012-06-01

    Full Text Available The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods with four replications. Assessments began at 15 days after sowing (DAS, and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems, leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.O objetivo da presente pesquisa foi comparar o crescimento das espécies de capim colchão D. ciliaris e D. nuda, em condições não-competitivas. Para isso, foram conduzidos dois experimentos, um de março a julho de 2010 e outro de fevereiro a junho de 2011. O delineamento experimental de ambos os ensaios foi inteiramente casualizado, perfazendo um esquema fatorial (2 épocas x 2 espécies de capim colchão x 12 períodos de

  3. Evaluation of phospherus uptake from Minjingu phosphate rock, growth and nodulation of agroforestry tree species on an acid soil from Kenya

    International Nuclear Information System (INIS)

    Karanja, N.K.; Mwendwa, K.A.

    2002-01-01

    A series of studies were carried out to study the effect of P application on fast growing multi-purpose trees. A greenhouse experiment was conducted to evaluate availability and uptake of phosphorus (P) from Minjingu phosphate rock (MPR). An acid soil and six agroforestry tree species namely Leucena leuco-cephala, Gliricidia sepium, Sesbania sesban, Grevillea robusta, Cassia siamea and Eucalyptus grandis were used. Phosphorus was applied at 25.8 mg P/ kg soil as Minjingu phosphate rock (MPR) or Triple Superphosphate (TSP). Pregerminated seedlings were transplanted and divided into two sequential harvests at 3 and 6 MAT (months after transplanting). 32 P isotope carrier free solution was added to transplanted seedlings at the beginning and when they were 3 months old. The soil was tested for isotopically exchangeable P by incubating the soil with the MPR and TSP. The soil was high in P-fixing capacity. At 3 MAT all the species except G. robusta gave a 150-250% significantly higher stem dry weights where P was added and L. leuco-cephala, S. sesban and C. siamea maintained this up to 6 MAT. The legumes and E. grandis where P was applied differed significantly from controls in root dry weight with Minjingu PR being superior with G.sepium and E. grandis. The legumes and E. grandis had significantly higher P uptake where P was applied at 3 MAT. The relative availability of MPR at 3 MAT showed that L.leucocephala and G. sepium derived 2.93 and 1.06 times more P from Minjingu PR than from TSP respectively. Data obtained from G. robusta P uptake showed that this species preferred soil P to externally supplied P in the three sampling periods. Tree species and fertilizer P interactions at 6 MAT were highly significant (P=0.01). Vesicular arbuscular mycorrhiza (VAM) inoculation improved growth, P uptake from MPR and nodulation of G. sepium seedlings. Inoculating L. leucocephala seedlings with VAM increased availability of P from MPR. (author)

  4. Altered Fermentation Performances, Growth, and Metabolic Footprints Reveal Competition for Nutrients between Yeast Species Inoculated in Synthetic Grape Juice-Like Medium

    Directory of Open Access Journals (Sweden)

    Stephanie Rollero

    2018-02-01

    Full Text Available The sequential inoculation of non-Saccharomyces yeasts and Saccharomyces cerevisiae in grape juice is becoming an increasingly popular practice to diversify wine styles and/or to obtain more complex wines with a peculiar microbial footprint. One of the main interactions is competition for nutrients, especially nitrogen sources, that directly impacts not only fermentation performance but also the production of aroma compounds. In order to better understand the interactions taking place between non-Saccharomyces yeasts and S. cerevisiae during alcoholic fermentation, sequential inoculations of three yeast species (Pichia burtonii, Kluyveromyces marxianus, Zygoascus meyerae with S. cerevisiae were performed individually in a synthetic medium. Different species-dependent interactions were evidenced. Indeed, the three sequential inoculations resulted in three different behaviors in terms of growth. P. burtonii and Z. meyerae declined after the inoculation of S. cerevisiae which promptly outcompeted the other two species. However, while the presence of P. burtonii did not impact the fermentation kinetics of S. cerevisiae, that of Z. meyerae rendered the overall kinetics very slow and with no clear exponential phase. K. marxianus and S. cerevisiae both declined and became undetectable before fermentation completion. The results also demonstrated that yeasts differed in their preference for nitrogen sources. Unlike Z. meyerae and P. burtonii, K. marxianus appeared to be a competitor for S. cerevisiae (as evidenced by the uptake of ammonium and amino acids, thereby explaining the resulting stuck fermentation. Nevertheless, the results suggested that competition for other nutrients (probably vitamins occurred during the sequential inoculation of Z. meyerae with S. cerevisiae. The metabolic footprint of the non-Saccharomyces yeasts determined after 48 h of fermentation remained until the end of fermentation and combined with that of S. cerevisiae. For

  5. Altered Fermentation Performances, Growth, and Metabolic Footprints Reveal Competition for Nutrients between Yeast Species Inoculated in Synthetic Grape Juice-Like Medium.

    Science.gov (United States)

    Rollero, Stephanie; Bloem, Audrey; Ortiz-Julien, Anne; Camarasa, Carole; Divol, Benoit

    2018-01-01

    The sequential inoculation of non- Saccharomyces yeasts and Saccharomyces cerevisiae in grape juice is becoming an increasingly popular practice to diversify wine styles and/or to obtain more complex wines with a peculiar microbial footprint. One of the main interactions is competition for nutrients, especially nitrogen sources, that directly impacts not only fermentation performance but also the production of aroma compounds. In order to better understand the interactions taking place between non-Saccharomyces yeasts and S. cerevisiae during alcoholic fermentation, sequential inoculations of three yeast species ( Pichia burtonii, Kluyveromyces marxianus, Zygoascus meyerae ) with S. cerevisiae were performed individually in a synthetic medium. Different species-dependent interactions were evidenced. Indeed, the three sequential inoculations resulted in three different behaviors in terms of growth. P. burtonii and Z. meyerae declined after the inoculation of S. cerevisiae which promptly outcompeted the other two species. However, while the presence of P. burtonii did not impact the fermentation kinetics of S. cerevisiae , that of Z. meyerae rendered the overall kinetics very slow and with no clear exponential phase. K. marxianus and S. cerevisiae both declined and became undetectable before fermentation completion. The results also demonstrated that yeasts differed in their preference for nitrogen sources. Unlike Z. meyerae and P. burtonii, K. marxianus appeared to be a competitor for S. cerevisiae (as evidenced by the uptake of ammonium and amino acids), thereby explaining the resulting stuck fermentation. Nevertheless, the results suggested that competition for other nutrients (probably vitamins) occurred during the sequential inoculation of Z. meyerae with S. cerevisiae . The metabolic footprint of the non- Saccharomyces yeasts determined after 48 h of fermentation remained until the end of fermentation and combined with that of S. cerevisiae . For instance

  6. Altered Fermentation Performances, Growth, and Metabolic Footprints Reveal Competition for Nutrients between Yeast Species Inoculated in Synthetic Grape Juice-Like Medium

    Science.gov (United States)

    Rollero, Stephanie; Bloem, Audrey; Ortiz-Julien, Anne; Camarasa, Carole; Divol, Benoit

    2018-01-01

    The sequential inoculation of non-Saccharomyces yeasts and Saccharomyces cerevisiae in grape juice is becoming an increasingly popular practice to diversify wine styles and/or to obtain more complex wines with a peculiar microbial footprint. One of the main interactions is competition for nutrients, especially nitrogen sources, that directly impacts not only fermentation performance but also the production of aroma compounds. In order to better understand the interactions taking place between non-Saccharomyces yeasts and S. cerevisiae during alcoholic fermentation, sequential inoculations of three yeast species (Pichia burtonii, Kluyveromyces marxianus, Zygoascus meyerae) with S. cerevisiae were performed individually in a synthetic medium. Different species-dependent interactions were evidenced. Indeed, the three sequential inoculations resulted in three different behaviors in terms of growth. P. burtonii and Z. meyerae declined after the inoculation of S. cerevisiae which promptly outcompeted the other two species. However, while the presence of P. burtonii did not impact the fermentation kinetics of S. cerevisiae, that of Z. meyerae rendered the overall kinetics very slow and with no clear exponential phase. K. marxianus and S. cerevisiae both declined and became undetectable before fermentation completion. The results also demonstrated that yeasts differed in their preference for nitrogen sources. Unlike Z. meyerae and P. burtonii, K. marxianus appeared to be a competitor for S. cerevisiae (as evidenced by the uptake of ammonium and amino acids), thereby explaining the resulting stuck fermentation. Nevertheless, the results suggested that competition for other nutrients (probably vitamins) occurred during the sequential inoculation of Z. meyerae with S. cerevisiae. The metabolic footprint of the non-Saccharomyces yeasts determined after 48 h of fermentation remained until the end of fermentation and combined with that of S. cerevisiae. For instance

  7. Effect of controlled inoculation with specific mycorrhizal fungi from the urban environment on growth and physiology of containerized shade tree species growing under different water regimes.

    Science.gov (United States)

    Fini, Alessio; Frangi, Piero; Amoroso, Gabriele; Piatti, Riccardo; Faoro, Marco; Bellasio, Chandra; Ferrini, Francesco

    2011-11-01

    The aim of this work was to evaluate the effects of selected mycorrhiza obtained in the urban environment on growth, leaf gas exchange, and drought tolerance of containerized plants growing in the nursery. Two-year-old uniform Acer campestre L., Tilia cordata Mill., and Quercus robur L. were inoculated with a mixture of infected roots and mycelium of selected arbuscular (maple, linden) and/or ectomycorrhiza (linden, oak) fungi and grown in well-watered or water shortage conditions. Plant biomass and leaf area were measured 1 and 2 years after inoculation. Leaf gas exchange, chlorophyll fluorescence, and water relations were measured during the first and second growing seasons after inoculation. Our data suggest that the mycelium-based inoculum used in this experiment was able to colonize the roots of the tree species growing in the nursery. Plant biomass was affected by water shortage, but not by inoculation. Leaf area was affected by water regime and, in oak and linden, by inoculation. Leaf gas exchange was affected by inoculation and water stress. V(cmax) and J(max) were increased by inoculation and decreased by water shortage in all species. F(v)/F(m) was also generally higher in inoculated plants than in control. Changes in PSII photochemistry and photosynthesis may be related to the capacity of inoculated plants to maintain less negative leaf water potential under drought conditions. The overall data suggest that inoculated plants were better able to maintain physiological activity during water stress in comparison to non-inoculated plants.

  8. Depletion of hepatoma-derived growth factor-related protein-3 induces apoptotic sensitization of radioresistant A549 cells via reactive oxygen species-dependent p53 activation

    International Nuclear Information System (INIS)

    Yun, Hong Shik; Hong, Eun-Hee; Lee, Su-Jae; Baek, Jeong-Hwa; Lee, Chang-Woo; Yim, Ji-Hye; Um, Hong-Duck; Hwang, Sang-Gu

    2013-01-01

    Highlights: •HRP-3 is a radiation- and anticancer drug-responsive protein in A549 cells. •Depletion of HRP-3 induces apoptosis of radio- and chemoresistant A549 cells. •Depletion of HRP-3 promotes ROS generation via inhibition of the Nrf2/HO-1 pathway. •Depletion of HRP-3 enhances ROS-dependent p53 activation and PUMA expression. -- Abstract: Biomarkers based on functional signaling have the potential to provide greater insight into the pathogenesis of cancer and may offer additional targets for anticancer therapeutics. Here, we identified hepatoma-derived growth factor-related protein-3 (HRP-3) as a radioresistance-related gene and characterized the molecular mechanism by which its encoded protein regulates the radio- and chemoresistant phenotype of lung cancer-derived A549 cells. Knockdown of HRP-3 promoted apoptosis of A549 cells and potentiated the apoptosis-inducing action of radio- and chemotherapy. This increase in apoptosis was associated with a substantial generation of reactive oxygen species (ROS) that was attributable to inhibition of the Nrf2/HO-1 antioxidant pathway and resulted in enhanced ROS-dependent p53 activation and p53-dependent expression of PUMA (p53 upregulated modulator of apoptosis). Therefore, the HRP-3/Nrf2/HO-1/ROS/p53/PUMA cascade is an essential feature of the A549 cell phenotype and a potential radiotherapy target, extending the range of targets in multimodal therapies against lung cancer

  9. Mangosenone F, A Furanoxanthone from Garciana mangostana, Induces Reactive Oxygen Species-Mediated Apoptosis in Lung Cancer Cells and Decreases Xenograft Tumor Growth.

    Science.gov (United States)

    Seo, Kyung Hye; Ryu, Hyung Won; Park, Mi Jin; Park, Ki Hun; Kim, Jin Hyo; Lee, Mi-Ja; Kang, Hyeon Jung; Kim, Sun Lim; Lee, Jin Hwan; Seo, Woo Duck

    2015-11-01

    Mangosenone F (MSF), a natural xanthone, was isolated form Carcinia mangotana, and a few studies have reported its glycosidase inhibitor effect. In this study we investigated the anti lung cancer effect of MSF both in vitro and in vivo. MSF inhibited cancer cell cytotoxicity and induced and induced apoptosis via reactive oxygen species (ROS) generation in NCI-H460. MSF treatment also showed in pronounced release of apoptogenic cytochrome c from the mitochondria to the cytosol, downregulation of Bcl-2 and Bcl-xL, and upregulation of Bax, suggesting that caspase-mediated pathways were involved in MSF-induced apoptosis. ROS activation of the mitogen-activated protein kinase signaling pathway was shown to play a predominant role in the apoptosis mechanism of MSF. Compared with cisplatin treatment, MSF treatment showed significantly increased inhibition of the growth of NCI-H460 cells xenografted in nude mice. Together, these results indicate the potential of MSF as a candidate natural anticancer drug by promoting ROS production. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Ozone air pollution effects on tree-ring growth,{delta}{sup 13}C, visible foliar injury and leaf gas exchange in three ozone-sensitive woody plant species

    Energy Technology Data Exchange (ETDEWEB)

    Novak, K. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland); Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Saurer, M. [Paul Scherrer Inst. Villigen (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Skelly, J.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Plant Pathology; Krauchi, N.; Schaub, M. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland)

    2007-07-15

    Species specific plant responses to tropospheric ozone pollution depend on a range of morphological, biochemical and physiological characteristics as well as environmental factors. The effects of ambient tropospheric ozone on annual tree-ring growth, {delta}{sup 13} C in the rings, leaf gas exchange and ozone-induced visible foliar injury in three ozone-sensitive woody plant species in southern Switzerland were assessed during the 2001 and 2002 growing seasons. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air and non-filtered air in open-top chambers, and to ambient air (AA) in open plots. The objective was to determine if a relationship exists between measurable ozone-induced effects at the leaf level and subsequent changes in annual tree-ring growth and {delta} {sup 13} C signatures. The visible foliar injury, early leaf senescence and premature leaf loss in all species was attributed to the ambient ozone exposures in the region. Ozone had pronounced negative effects on net photosynthesis and stomatal conductance in all species in 2002 and in V. lantana and F. excelsior in 2001. Water-use efficiency decreased and intercellular carbon dioxide concentrations increased in all species in response to ozone in 2002 only. The width and {delta}{sup 13} C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased {delta}{sup 13} C in all species, suggesting that the timing of ozone exposure and extent of leaf-level responses may be relevant in determining the sensitivity of tree productivity to ozone exposure. 48 refs., 4 tabs., 2 figs.

  11. Characterisation of the ozone sensitivity of Central European plant species: relation to taxonomy, ecology, growth rates and leaf density; Charakterisierung der Ozonsensitivitaet mitteleuropaeischer Pflanzenarten: Beziehung zu Taxonomie, Oekologie, Wachstumsraten und Blattdichte

    Energy Technology Data Exchange (ETDEWEB)

    Franzaring, J.

    2000-07-01

    Fumigation experiments with wild plant species performed in recent years are not necessarily representative for the Central European flora, especially when it comes down to the use of species from red data books in these studies. Moreover, ozone experiments are not representative with respect to plant life forms, taxonomy and ecology. However, first tendencies can be derived: Legumes and Compositae are families comprising many sensitive species with regard to acute injury and growth reductions due to ozone. In contrast to this, the family of Sweet Grasses contains some species with growth stimulations due to ozone. Fastgrowing ruderal strategists and competitive species tend to respond more pronounced than slow-growing species. On the average, plant species with acute injury have thinner leaves than those showing no symptoms. (orig.) [German] Die bislang in Begasungsversuchen untersuchten Wildpflanzenarten repraesentieren nur einen kleinen Teil der mitteleuropaeischen Flora, besonders die Arten der Roten Liste sind noch unterrepraesentiert. Auch hinsichtlich Lebensformen, Taxonomie und Oekologie ist die Ozonwirkungsforschung an Wildpflanzen nur bedingt repraesentativ. Aus den bislang durchgefuehrten Experimenten lassen sich jedoch erste Tendenzen erkennen: Die Familien der Schmetterlings- und Korbblueter enthalten viele ozonsensitive Taxa, was akute Schaeden und Wuchsminderungen anbelangt. In der Familie der Suessgraeser gibt es andererseits Arten, die auf Ozon mit einer Wachstumsstimulierung reagieren. Schnellwuechsige Ruderalstrategen und konkurrenzstarke Arten erweisen sich insgesamt ozonsensitiver als die langsamwuechsigen Arten. Pflanzenarten mit akuter Blattschaedigung haben im Mittel duennere Blaetter als Arten ohne sichtbare Schaeden. (orig.)

  12. Species richness, abundance, and composition of hypogeous and epigeous ectomycorrhizal fungal sporocarps in young, rotation-age, and old-growth stands of Douglas-fir (Pseudotsuga menziesii) in the Cascade Range of Oregon, U.S.A.

    Science.gov (United States)

    J.E. Smith; R. Molina; M.M.P. Huso; D.L. Luoma; D. McKay; M.A. Castellano; T. Lebel; Y. Valachovic

    2002-01-01

    Knowledge of the community structure of ectomycorrhizal fungi among successional forest age-classes is critical for conserving fungal species diversity. Hypogeous and epigeous sporocarps were collected from three replicate stands in each of three forest age-classes (young, rotation-age, and old-growth) of Douglas-fir (Pseudotsuga menziesii (Mirb.)...

  13. Evaluation of Growth and Species Composition of Weeds in Maize-Cowpea Intercropping based on Additive Series under Organic Farming Condition

    Directory of Open Access Journals (Sweden)

    Hamdollah Eskandari

    2016-11-01

    Full Text Available Introduction Weeds are main factors reducing crops yield, especially under organic farming conditions (. It has been reported that weed populations are more in organic farming compared to conventional cropping systems, resulting in more reduction of growth and yield. Although the chemical control is a fast and effective way for controlling weed populations, some negative impacts of the recent weed management on public health and the natural environment, increased the concerns of using weed chemical compositions. Thus, non-chemical weed control is in high importance. Intercropping, an agronomical operation in which two or more crops are grown simultaneously in the same field, is one of the most important methods for increasing biodiversity in agricultural ecosystems (Amosse et al., 2013; Rostami et al., 2009; Yuan-Quan et al., 2012. Therefore, the current research was aimed to evaluate the possible non chemical controlling of weeds in a maize-cowpea intercropping system. Materials and methods A field experiment was conducted in the north of Khuzestan during the growing season 2013-2014. The experiment was based on a randomized complete block design with three replications. Maize and cowpea were planted in two sole crop systems and four intercropping systems based on an additive series, including T1:100 percent maize+25 percent cowpea, T2: 100 percent maize+50 percent cowpea, T3: 100 percent maize+75 percent cowpea and T4: 100 percent maize+100 percent cowpea. No chemical materials (fertilizer and pesticide were used during growing season. Environmental usage by intercropping patterns was evaluated by measuring photosynthetically active radiations (PAR (mean of five points in each plot, selected randomly and soil moisture content at three stages. At harvest time, all plants of each plot were harvested and grouped and weighed according to their species type. Complementary effect of intercropping in using environmental resources was calculated using

  14. Effects of low atmospheric CO2 and elevated temperature during growth on the gas exchange responses of C3, C3-C4 intermediate, and C4 species from three evolutionary lineages of C4 photosynthesis.

    Science.gov (United States)

    Vogan, Patrick J; Sage, Rowan F

    2012-06-01

    This study evaluates acclimation of photosynthesis and stomatal conductance in three evolutionary lineages of C(3), C(3)-C(4) intermediate, and C(4) species grown in the low CO(2) and hot conditions proposed to favo r the evolution of C(4) photosynthesis. Closely related C(3), C(3)-C(4), and C(4) species in the genera Flaveria, Heliotropium, and Alternanthera were grown near 380 and 180 μmol CO(2) mol(-1) air and day/night temperatures of 37/29°C. Growth CO(2) had no effect on photosynthetic capacity or nitrogen allocation to Rubisco and electron transport in any of the species. There was also no effect of growth CO(2) on photosynthetic and stomatal responses to intercellular CO(2) concentration. These results demonstrate little ability to acclimate to low CO(2) growth conditions in closely related C(3) and C(3)-C(4) species, indicating that, during past episodes of low CO(2), individual C(3) plants had little ability to adjust their photosynthetic physiology to compensate for carbon starvation. This deficiency could have favored selection for more efficient modes of carbon assimilation, such as C(3)-C(4) intermediacy. The C(3)-C(4) species had approximately 50% greater rates of net CO(2) assimilation than the C(3) species when measured at the growth conditions of 180 μmol mol(-1) and 37°C, demonstrating the superiority of the C(3)-C(4) pathway in low atmospheric CO(2) and hot climates of recent geological time.

  15. The impact of tree age on biomass growth and carbon accumulation capacity: A retrospective analysis using tree ring data of three tropical tree species grown in natural forests of Suriname.

    Science.gov (United States)

    Köhl, Michael; Neupane, Prem R; Lotfiomran, Neda

    2017-01-01

    The world's forests play a pivotal role in the mitigation of global climate change. By photosynthesis they remove CO2 from the atmosphere and store carbon in their biomass. While old trees are generally acknowledged for a long carbon residence time, there is no consensus on their contribution to carbon accumulation due to a lack of long-term individual tree data. Tree ring analyses, which use anatomical differences in the annual formation of wood for dating growth zones, are a retrospective approach that provides growth patterns of individual trees over their entire lifetime. We developed time series of diameter growth and related annual carbon accumulation for 61 trees of the species Cedrela odorata L. (Meliacea), Hymenaea courbaril L. (Fabacea) and Goupia glabra Aubl. (Goupiacea). The trees grew in unmanaged tropical wet-forests of Suriname and reached ages from 84 to 255 years. Most of the trees show positive trends of diameter growth and carbon accumulation over time. For some trees we observed fluctuating growth-periods of lower growth alternate with periods of increased growth. In the last quarter of their lifetime trees accumulate on average between 39 percent (C. odorata) and 50 percent (G. glabra) of their final carbon stock. This suggests that old-growth trees in tropical forests do not only contribute to carbon stocks by long carbon resistance times, but maintain high rates of carbon accumulation at later stages of their life time.

  16. The impact of tree age on biomass growth and carbon accumulation capacity: A retrospective analysis using tree ring data of three tropical tree species grown in natural forests of Suriname.

    Directory of Open Access Journals (Sweden)

    Michael Köhl

    Full Text Available The world's forests play a pivotal role in the mitigation of global climate change. By photosynthesis they remove CO2 from the atmosphere and store carbon in their biomass. While old trees are generally acknowledged for a long carbon residence time, there is no consensus on their contribution to carbon accumulation due to a lack of long-term individual tree data. Tree ring analyses, which use anatomical differences in the annual formation of wood for dating growth zones, are a retrospective approach that provides growth patterns of individual trees over their entire lifetime. We developed time series of diameter growth and related annual carbon accumulation for 61 trees of the species Cedrela odorata L. (Meliacea, Hymenaea courbaril L. (Fabacea and Goupia glabra Aubl. (Goupiacea. The trees grew in unmanaged tropical wet-forests of Suriname and reached ages from 84 to 255 years. Most of the trees show positive trends of diameter growth and carbon accumulation over time. For some trees we observed fluctuating growth-periods of lower growth alternate with periods of increased growth. In the last quarter of their lifetime trees accumulate on average between 39 percent (C. odorata and 50 percent (G. glabra of their final carbon stock. This suggests that old-growth trees in tropical forests do not only contribute to carbon stocks by long carbon resistance times, but maintain high rates of carbon accumulation at later stages of their life time.

  17. Mine waste disposal leads to lower coral cover, reduced species richness and a predominance of simple coral growth forms on a fringing coral reef in Papua New Guinea.

    Science.gov (United States)

    Haywood, M D E; Dennis, D; Thomson, D P; Pillans, R D

    2016-04-01

    A large gold mine has been operating at the Lihir Island Group, Papua New Guinea since 1997. The mine disposes of waste rock in nearshore waters, impacting nearby coral communities. During 2010, 2012 we conducted photographic surveys at 73 sites within 40 km of the mine to document impacts of mining operations on the hard coral communities. Coral communities close to the mine (∼2 km to the north and south of the mine) were depaurperate, but surprisingly, coral cover and community composition beyond this range appeared to be relatively similar, suggesting that the mine impacts were limited spatially. In particular, we found mining operations have resulted in a significant decrease in coral cover (4.4% 1.48 km from the disposal site c.f. 66.9% 10.36 km from the disposal site), decreased species richness and a predominance of less complex growth forms within ∼2 km to the north and south of the mine waste disposal site. In contrast to the two 'snapshot' surveys of corals performed in 2010 and 2012, long term data (1999-2012) based on visual estimates of coral cover suggested that impacts on coral communities may have been more extensive than this. With global pressures on the world's coral reefs increasing, it is vital that local, direct anthropogenic pressures are reduced, in order to help offset the impacts of climate change, disease and predation. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  18. Effects of in ovo 2,3,7,8-TCDD exposure on hepatic ethoxyresorufin O-deethylase (EROD) induction and growth-related parameters in avian species

    Energy Technology Data Exchange (ETDEWEB)

    Janz, D.M.; Bellward, G.D. [Univ. of British Columbia, Vancouver, British Columbia (Canada). Faculty of Pharmaceutical Sciences

    1994-12-31

    The effects of early in ovo TCDD exposure on CYP1A1 induction and indices of growth were determined in domestic chicken (Gallus gallus) and pigeon (Columba livia) hatchlings. TCDD (in corn oil) was injected into the air sac of eggs on embryonic day 4 (E4) (chickens, 0.1 {mu}g/kg egg; pigeons, 1.0 {mu}g/kg egg), and on E14 (pigeons, 3.0 {mu}g/kg egg). In chickens, hepatic EROD was induced 13, 15, 34, and 43-fold above control activities on E19, day of hatch (DO), day 2 after hatch (D2), and D4, respectively. Plasma thyroid hormone (T{sub 3} T{sub 4}) concentrations, which are known to peak during the perinatal period in chickens, were not affected by TCDD treatment when measured on E17, E19, D0, D2, and D4. In pigeons injected on E4, EROD was induced 15 and 6-fold on D0 and D7, respectively. There were significant decreases in yolk-free body weight, crown-rump, tibia, culmen, and wing lengths, and an elevated liver to body weight ratio (LSI) in TCDD-treated pigeons raised to D7 (p < 0.01). In pigeons injected on E14 (3{mu}g/kg), EROD was induced 14 and 10-fold on D0 and D7, respectively. Crown-rump and culmen lengths were decreased (p < 0.05) and LSI was increased (p < 0.01) on D0. There were significant decreases in all morphological parameters, and an increased LSI on D7 (p < 0.01) in TCDD-treated birds. These techniques will be used in further studies to investigate possible mechanisms of TCDD embryotoxicity in wild avian species, such as the great blue heron (Ardea herodias).

  19. The effect of water extracts from leaves of Festuca rubra, F. ovina and F. Arundinacea on the initial growth and development of other grass species

    Directory of Open Access Journals (Sweden)

    Halina Lipińska

    2013-07-01

    Full Text Available The allelopathic effect of plants is one of the least known factors determining the stability of lawn swards. Leaves are a rich source of allelopathic substances. Washed out by rain or dew drops, or released during biomass decomposition, these substances can impact plants. In practice, cut sward is often left on the lawn surface and can have an allelopathic effect on regrowing plants. The effect of released allelochemicals depends on many factors, including their concentration. Hence, in order to maintain the high functional properties of the lawn, information is needed on the critical concentrations of allelochemicals inhibiting plant growth and development. Laboratory research was thus undertaken (on Petri dishes to evaluate the effect of various water extracts of leaves of selected lawn grass cultivars. The following cultivars were the donors: 'Areta', 'Nimba', 'Olivia' (Festuca rubra; 'Espro', 'Pintor' (F. ovina,and 'Asterix' (F. arundinacea, while the acceptors were: 'Niwa' (Agrostis capillaris, 'Asterix' (Festuca arundinacea, 'Espro' (F. ovina, 'Areta' (F. rubra, 'Stadion' (Lolium perenne, and 'Bila' (Poa pratensis – the species frequently sown in lawns. In the control treatments, distilled water was applied to the substrate. The experiment revealed that the effect of water extracts of leaves varied depending on their concentration and donor variety as well as the sensitivity of the acceptor (the test plant. In comparison with the control treatments, the strongest negative impact was caused by the cultivars 'Olivia' (F. rubraand 'Pintor' (F. ovina, followed by 'Asterix' (F. arundinacea. Among the acceptors, the greatest sensitivity to the presence of allelochemicals was shown by A. capillaris, and the smallest by F. arundinacea. .

  20. Effects of predicted future and current atmospheric temperature and [CO2] and high and low soil moisture on gas exchange and growth of Pinus taeda seedlings at cool and warm sites in the species range.

    Science.gov (United States)

    Wertin, Timothy M; McGuire, Mary Anne; Teskey, Robert O

    2012-07-01

    Predicted future changes in air temperature and atmospheric CO(2) concentration ([CO(2)]), coupled with altered precipitation, are expected to substantially affect tree growth. Effects on growth may vary considerably across a species range, as temperatures vary from sub-optimal to supra-optimal for growth. We performed an experiment simultaneously at two locations in the current range of loblolly pine, a cool site and a warm site, to examine the effect of future climate conditions on growth of loblolly pine seedlings in contrasting regions of the species range. At both sites 1-year-old loblolly pine seedlings were grown in current (local ambient temperature and [CO(2)]) and predicted future atmospheric conditions (ambient +2 °C temperature and 700 μmol mol(-1) [CO(2)]). Additionally, high and low soil moisture treatments were applied within each atmospheric treatment at each site by altering the amount of water provided to the seedlings. Averaged across water treatments, photosynthesis (A(net)) was 31% greater at the cool site and 34% greater at the warm site in elevated temperature and [CO(2)] compared with ambient temperature. Biomass accumulation was also stimulated by 38% at the cool site and by 24% at the warm site in that treatment. These results suggest that a temperature increase of 2 °C coupled with an increase in [CO(2)] (predicted future climate) will create conditions favorable for growth of this species. Reduced soil moisture decreased growth in both current and predicted atmospheric conditions. Biomass accumulation and A(net) were reduced by ∼39 and 17%, respectively, in the low water treatment. These results suggest that any benefit of future atmospheric conditions may be negated if soil moisture is reduced by altered precipitation patterns.

  1. Reactive oxygen species via redox signaling to PI3K/AKT pathway contribute to the malignant growth of 4-hydroxy estradiol-transformed mammary epithelial cells.

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    Victor O Okoh

    Full Text Available The purpose of this study was to investigate the effects of 17-β-estradiol (E2-induced reactive oxygen species (ROS on the induction of mammary tumorigenesis. We found that ROS-induced by repeated exposures to 4-hydroxy-estradiol (4-OH-E2, a predominant catechol metabolite of E2, caused transformation of normal human mammary epithelial MCF-10A cells with malignant growth in nude mice. This was evident from inhibition of estrogen-induced breast tumor formation in the xenograft model by both overexpression of catalase as well as by co-treatment with Ebselen. To understand how 4-OH-E2 induces this malignant phenotype through ROS, we investigated the effects of 4-OH-E2 on redox-sensitive signal transduction pathways. During the malignant transformation process we observed that 4-OH-E2 treatment increased AKT phosphorylation through PI3K activation. The PI3K-mediated phosphorylation of AKT in 4-OH-E2-treated cells was inhibited by ROS modifiers as well as by silencing of AKT expression. RNA interference of AKT markedly inhibited 4-OH-E2-induced in vitro tumor formation. The expression of cell cycle genes, cdc2, PRC1 and PCNA and one of transcription factors that control the expression of these genes - nuclear respiratory factor-1 (NRF-1 was significantly up-regulated during the 4-OH-E2-mediated malignant transformation process. The increased expression of these genes was inhibited by ROS modifiers as well as by silencing of AKT expression. These results indicate that 4-OH-E2-induced cell transformation may be mediated, in part, through redox-sensitive AKT signal transduction pathways by up-regulating the expression of cell cycle genes cdc2, PRC1 and PCNA, and the transcription factor - NRF-1. In summary, our study has demonstrated that: (i 4-OH-E2 is one of the main estrogen metabolites that induce mammary tumorigenesis and (ii ROS-mediated signaling leading to the activation of PI3K/AKT pathway plays an important role in the generation of 4-OH-E2

  2. Differences in internalization and growth of Escherichia coli O157:H7 within the apoplast of edible plants, spinach and lettuce, compared with the model species Nicotiana benthamiana

    OpenAIRE

    Wright, Kathryn M.; Crozier, Louise; Marshall, Jacqueline; Merget, Bernhard; Holmes, Ashleigh; Holden, Nicola J.

    2017-01-01

    Summary Internalization of food?borne bacteria into edible parts of fresh produce plants represents a serious health risk. Therefore, internalization of verocytotoxigenic E.?coli O157:H7 isolate Sakai was assessed in two species associated with outbreaks, spinach (Spinacia oleracea) and lettuce (Lactuca sativa) and compared to the model species Nicotiana benthamiana. Internalization occurred in the leaves and roots of spinach and lettuce throughout a 10?day time?course. The plant species, tis...

  3. Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas

    Science.gov (United States)

    Adrian G. Grell; Michael G. Shelton; Eric Heitzman

    2005-01-01

    Old-growth bottomland hardwood-Pinus taeda L. forests are rare in Arkansas, and the complex relationships between plant communities and environmental conditions have not been well described in these forests. To investigate these relationships, a digital elevation model was developed for a 16.2 ha old-growth bottomland hardwood-Pinus taeda forest in...

  4. Canopy treatment influences growth of replacement tree species in Fraxinus nigra forests threatened by the emerald ash borer in Minnesota, USA

    Science.gov (United States)

    Christopher E. Looney; Anthony W. D' Amato; Brian J. Palik; Robert A. Slesak

    2017-01-01

    Fraxinus nigra Marsh. (black ash), a dominant tree species of wetland forests in northern Minnesota, USA, is imperiled by the invasive insect emerald ash borer (EAB; Agrilus planipennis Fairmaire, 1888). Regeneration of associated tree species is generally low in F. nigra forests and could be impacted...

  5. Assessment of Tools for Marker-Assisted Selection in a Marine Commercial Species: Significant Association between MSTN-1 Gene Polymorphism and Growth Traits

    Directory of Open Access Journals (Sweden)

    Irma Sánchez-Ramos

    2012-01-01

    Full Text Available Growth is a priority trait from the point of view of genetic improvement. Molecular markers linked to quantitative trait loci (QTL have been regarded as useful for marker-assisted selection in complex traits as growth. Polymorphisms have been studied in five candidate genes influencing growth in gilthead seabream (Sparus aurata: the growth hormone (GH, insulin-like growth factor-1 (IGF-1, myostatin (MSTN-1, prolactin (PRL, and somatolactin (SL genes. Specimens evaluated were from a commercial broodstock comprising 131 breeders (from which 36 males and 44 females contributed to the progeny. In all samples eleven gene fragments, covering more than 13,000 bp, generated by PCR-RFLP, were analyzed; tests were made for significant associations between these markers and growth traits. ANOVA results showed a significant association between MSTN-1 gene polymorphism and growth traits. Pairwise tests revealed several RFLPs in the MSTN-1 gene with significant heterogeneity of genotypes among size groups. PRL and MSTN-1 genes presented linkage disequilibrium. The MSTN-1 gene was mapped in the centromeric region of a medium-size acrocentric chromosome pair.

  6. Both the stimulation and inhibition of root hair growth induced by extracellular nucleotides in Arabidopsis are mediated by nitric oxide and reactive oxygen species.

    Science.gov (United States)

    Clark, Greg; Wu, Michael; Wat, Noel; Onyirimba, James; Pham, Trieu; Herz, Niculin; Ogoti, Justin; Gomez, Delmy; Canales, Arinda A; Aranda, Gabriela; Blizard, Misha; Nyberg, Taylor; Terry, Anne; Torres, Jonathan; Wu, Jian; Roux, Stanley J

    2010-11-01

    Root hairs secrete ATP as they grow, and extracellular ATP and ADP can trigger signaling pathways that regulate plant cell growth. In several plant tissues the level of extracellular nucleotides is limited in part by ectoapyrases (ecto-NTPDases), and the growth of these tissues is strongly influenced by their level of ectoapyrase expression. Both chemical inhibition of ectoapyrase activity and suppression of the expression of two ectoapyrase enzymes by RNAi in Arabidopsis resulted in inhibition of root hair growth. As assayed by a dose-response curve, different concentrations of the poorly hydrolysable nucleotides, ATPγS and ADPβS, could either stimulate (at 7.5-25 μM) or inhibit (at ≥ 150 μM) the growth rate of root hairs in less than an hour. Equal amounts of AMPS, used as a control, had no effect on root hair growth. Root hairs of nia1nia2 mutants, which are suppressed in nitric oxide (NO) production, and of atrbohD/F mutants, which are suppressed in the production of H(2)O(2), did not show growth responses to applied nucleotides, indicating that the growth changes induced by these nucleotides in wild-type plants were likely transduced via NO and H(2)O(2) signals. Consistent with this interpretation, treatment of root hairs with different concentrations of ATPγS induced different accumulations of NO and H(2)O(2) in root hair tips. Two mammalian purinoceptor antagonists also blocked the growth responses induced by extracellular nucleotides, suggesting that they were initiated by a receptor-based mechanism.

  7. Crescimento e fenologia de espécies de Jatropha durante a estação chuvosa Growth and phenology of species of Jatropha during the rainy season

    Directory of Open Access Journals (Sweden)

    Messias F. de Queiroz

    2013-04-01

    Full Text Available Jatropha curcas L., Jatropha mollissima (Pohl Baill e Jatropha gossypiifolia L. são Euforbiáceas com potencial para produção de biodiesel e uso na indústria farmacêutica e em cosméticos. Objetivou-se, com este trabalho, avaliá-las em termos de crescimento e fenologia em pesquisa de campo. Adotou-se o delineamento experimental em blocos casualisados contendo na parcela 18 plantas e tendo área útil de 15 m². Nos estudos fenológicos das plantas foram consideradas as seguintes fases: estabelecimento/crescimento vegetativo, floração, frutificação e maturação/colheita. As fases fenológicas das espécies diferiram cronologicamente. Jatropha mollissima cresceu mais do que as outras espécies em altura de plantas enquanto Jatropha curcas cresceu mais em diâmetro caulinar. As maiores taxas de crescimento relativo em altura de plantas ocorreram durante o crescimento vegetativo com os maiores valores sendo registrados em Jatropha mollissima enquanto as maiores taxas de crescimento relativo, também no crescimento vegetativo, foram registradas em Jatropha curcas. As menores taxas de crescimento relativo em altura de plantas e diâmetro caulinar das espécies estudadas coincidiram com as fases reprodutivas.Jatropha curcas L., Jatropha mollissima (Pohl Baill and Jatropha gossypiifolia L. are Euphorbiaceae with potential for biodiesel production and use in pharmaceutical and cosmetic industries. The aim of this study was to evaluate these species in terms of growth and phenology in a field experiment. In this study an experimental design of randomized blocks was adopted. The experimental plot had 18 plants and a useful plot area of 15 m². In the phenological studies of plants the following phases were considered: establishment/vegetative growth, flowering, fruiting and ripening/harvest. The phenological stages of the species differed chronologically. Jatropha mollissima outgrew the others in plant height, while Jatropha curcas outgrew the

  8. 1995 Volvo Award in basic sciences. The use of an osteoinductive growth factor for lumbar spinal fusion. Part II: Study of dose, carrier, and species.

    Science.gov (United States)

    Boden, S D; Schimandle, J H; Hutton, W C

    1995-12-15

    Efficacy of a bovine-derived osteoinductive growth factor was studied in a rabbit model and in a nonhuman primate model of posterolateral lumbar spinal fusion. To determine the minimum effective dose of growth factor and the influence of different carrier material on the outcome of intertransverse process lumbar fusion. Bone morphogenetic proteins and related growth factors are becoming increasingly available in purified extract or genetically engineered forms and are capable of inducing new bone formation in vivo. Osteoinductive growth factors to enhance lumbar spinal infusion have not been well studied in models of posterolateral intertransverse process fusion. Because of the diminished potential of bone regeneration in primates (including humans) compared with phylogenetically lower animals, extrapolations regarding dose and efficacy cannot be made directly from results obtained in experiments performed on phylogenetically lower animals. Experiments on non-human primates are a critical step before attempting to use these growth factors on humans. METHODS. One hundred fifteen adult New Zealand white rabbits and 10 adult rhesus macaques underwent single level posterolateral intertransverse process lumbar spinal arthrodesis to evaluate different doses and carrier materials for a bovine-derived osteoinductive bone protein extract. Rabbit fusion masses were evaluated 5 weeks after arthrodesis by manual palpation, radiography, biomechanical testing, and light microscopy. Monkey fusion masses were evaluated 12 weeks after arthrodesis by radiography and light microscopy. Successful posterolateral intertransverse process spinal fusions were achieved in the rabbit models using an osteoinductive growth factor with three different carriers (autogenous iliac bone, demineralized allogeneic bone matrix, and natural coral). There was a dose-dependent response to the osteoinductive growth factor in the rabbit model, indicating that a threshold must be overcome before bone

  9. PpeTAC1 promotes the horizontal growth of branches in peach trees and is a member of a functionally conserved gene family found in diverse plants species.

    Science.gov (United States)

    Dardick, Chris; Callahan, Ann; Horn, Renate; Ruiz, Karina B; Zhebentyayeva, Tetyana; Hollender, Courtney; Whitaker, Michael; Abbott, Albert; Scorza, Ralph

    2013-08-01

    Trees are capable of tremendous architectural plasticity, allowing them to maximize their light exposure under highly competitive environments. One key component of tree architecture is the branch angle, yet little is known about the molecular basis for the spatial patterning of branches in trees. Here, we report the identification of a candidate gene for the br mutation in Prunus persica (peach) associated with vertically oriented growth of branches, referred to as 'pillar' or 'broomy'. Ppa010082, annotated as hypothetical protein in the peach genome sequence, was identified as a candidate gene for br using a next generation sequence-based mapping approach. Sequence similarity searches identified rice TAC1 (tiller angle control 1) as a putative ortholog, and we thus named it PpeTAC1. In monocots, TAC1 is known to lead to less compact growth by increasing the tiller angle. In Arabidopsis, an attac1 mutant showed more vertical branch growth angles, suggesting that the gene functions universally to promote the horizontal growth of branches. TAC1 genes belong to a gene family (here named IGT for a shared conserved motif) found in all plant genomes, consisting of two clades: one containing TAC1-like genes; the other containing LAZY1, which contains an EAR motif, and promotes vertical shoot growth in Oryza sativa (rice) and Arabidopsis through influencing polar auxin transport. The data suggest that IGT genes are ancient, and play conserved roles in determining shoot growth angles in plants. Understanding how IGT genes modulate branch angles will provide insights into how different architectural growth habits evolved in terrestrial plants. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  10. CRESCIMENTO INICIAL DE ESPÉCIES FLORESTAIS DE DIFERENTES GRUPOS SUCESSIONAIS EM RESPOSTA A DOSES DE FÓSFORO INITIAL GROWTH OF FOREST SPECIES OF DIFFERENT SUCCESSIONAL GROUPS IN RESPONSE TO PHOSPHORUS DOSES

    Directory of Open Access Journals (Sweden)

    ÁLVARO VILELA DE RESENDE

    1999-11-01

    phosphorus supply for the adequate development of these species. The climaxes species showed to have low sensitivity to phosphorus supply, reflecting a lower requirement in the initial growth period. The differences in relation to growth rate and seed size may be connected to the contrasting behavior observed for pioneers and climaxes species.

  11. Growth performance and feed conversion efficiency of three edible mealworm species (Coleoptera: Tenebrionidae) on diets composed of organic by-products

    NARCIS (Netherlands)

    Broekhoven, van S.; Oonincx, D.G.A.B.; Huis, van A.; Loon, van J.J.A.

    2015-01-01

    Insects receive increasing attention as an alternative protein-rich food source for humans. Producing edible insects on diets composed of organic by-products could increase sustainability. In addition, insect growth rate and body composition, and hence nutritional quality, can be altered by diet.

  12. Do rising temperatures always increase forest productivity? Interacting effects of temperature, precipitation, cloudiness and soil texture on tree species growth and competition

    Science.gov (United States)

    Eric J. Gustafson; Brian R. Miranda; Arjan M.G. De Bruijn; Brian R. Sturtevant; Mark E. Kubiske

    2017-01-01

    Forest landscape models (FLM) are increasingly used to project the effects of climate change on forested landscapes, yet most use phenomenological approaches with untested assumptions about future forest dynamics. We used a FLM that relies on first principles to mechanistically simulate growth (LANDIS-II with PnET-Succession) to systematically explore how landscapes...

  13. Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios.

    Science.gov (United States)

    Wyatt, Lauren H; Diringer, Sarah E; Rogers, Laura A; Hsu-Kim, Heileen; Pan, William K; Meyer, Joel N

    2016-03-15

    The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.

  14. Rank reversals in tree growth along tree size, competition and climatic gradients for four forest canopy dominant species in Central Spain

    NARCIS (Netherlands)

    Sánchez-Gómez, D.; Zavala, M.A.; Schalkwijk, D.B.V.; Urbieta, I.R.; Valladares, F.

    2008-01-01

    Interspecific differences in tree growth patterns with respect to biotic and abiotic factors are key for understanding forest structure and dynamics, and predicting potential changes under climate change. • Repeated observations from the Spanish Forest Inventory (SFI) were used to parameterize

  15. Efeito de Glomus etunicatum e fósforo no crescimento inicial de espécies arbóreas em semeadura direta Effects of Glomus etunicatum and phosphorus on initial growth of woody species at direct seeding

    Directory of Open Access Journals (Sweden)

    Waldo Wilfredo Flores-Aylas

    2003-02-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da disponibilidade de P no solo, da micorriza formada por Glomus etunicatum e de Mycoform, um estimulante desta última, no crescimento e competição inicial de seis espécies arbóreas semeadas diretamente. O trabalho foi realizado em casa de vegetação com as espécies Senna macranthera (fedegoso, Guazuma ulmifolia (mutamba, Senna multijuga (cássia-verrugosa, Solanum granuloso-leprosum (gravitinga, Schinus terebenthifolius (aroeira e Trema micrantha (trema, em solo com níveis de P na solução considerados muito baixo, baixo e alto, com inoculação ou não do fungo micorrízico arbuscular G. etunicatum, além do tratamento G. etunicatum + Mycoform. O crescimento das mudas respondeu à inoculação em P muito baixo e baixo. As mudas apresentaram moderada dependência das micorrizas, não respondendo ao G. etunicatum em P alto. Gravitinga morreu em P muito baixo, mas foi dominante com P baixo e alto. Fedegoso foi dominante com P muito baixo, mostrando-se adaptado à baixa fertilidade. G. etunicatum influenciou a dominância das espécies, auxiliando as menos competitivas e gerando maior equilíbrio. Mycoform influenciou pouco o crescimento, nutrição e competição. O crescimento de espécies pioneiras semeadas diretamente é favorecido pela elevação do P e pelas micorrizas, as quais também favorecem o equilíbrio entre espécies.The objective of this work was to evaluate the effects of soil P availability, mycorrhiza and a mycorrhiza stimulatory product (Mycoform upon growth and initial competition of six sown woody species, in the greenhouse. The species Senna macranthera, Guazuma ulmifolia, Senna multijuga, Solanum granuloso-leprosum, Schinus terebenthifolius and Trema micrantha were sown together in a soil with very low, low and high levels of P in soil solution combined with inoculation treatments of the arbuscular mycorrhizal fungus Glomus etunicatum, G. etunicatum + Mycoform and a

  16. Parallel evolution in an invasive plant species : evolutionary changes in allocation to growth, defense, competitive ability and regrowth of invasive Jacobaea vulgaris

    NARCIS (Netherlands)

    Lin, Tiantian

    2015-01-01

    Although the introduction of invasive plant species in a given area causes economic and ecological problems, it still provides an ideal opportunity for ecologists to study evolutionary changes. According to the Evolution of Increased Competitive Ability hypothesis and Shifting Defense Hypothesis,

  17. Consequences of sex-specific growth on sibling competition in black-headed gulls : A sexually-size dimorphic species with scramble competition

    NARCIS (Netherlands)

    Mueller, Wendt; Groothuis, Ton G. G.; Dijkstra, Cor

    2007-01-01

    Biased mortality of the larger sex during the early developmental period has been reported for a number of size-dimorphic bird species. This can partly be explained by the fact that growing to larger size renders the larger sex more vulnerable to food shortage. However, since sibling rivalry is

  18. Influence of age on growth efficiency of Tsuga canadensis and Picea rubens trees in mixed-species, multiaged northern conifer stands

    Science.gov (United States)

    Robert S. Seymour; Laura S. Kenefic

    2002-01-01

    Well-known patterns in the fundamental relationship between tree-level stemwood volume increment (VINC) and projected leaf area (PLA) are examined and quantified for Tsuga Canadensis (L.) Carriere (eastern hemlock) and Picea rubens Sarg. (red spruce) growing in managed, mixed-species, multiaged stands in east-central Maine, U.S.A....

  19. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  20. Drought tolerance and growth in populations of a wide-ranging tree species indicate climate change risks for the boreal north.

    Science.gov (United States)

    Montwé, David; Isaac-Renton, Miriam; Hamann, Andreas; Spiecker, Heinrich

    2016-02-01

    Choosing drought-tolerant planting stock in reforestation programs may help adapt forests to climate change. To inform such reforestation strategies, we test lodgepole pine (Pinus contorta Doug. ex Loud. var latifolia Englm.) population response to drought and infer potential benefits of a northward transfer of seeds from drier, southern environments. The objective is addressed by combining dendroecological growth analysis with long-term genetic field trials. Over 500 trees originating from 23 populations across western North America were destructively sampled in three experimental sites in southern British Columbia, representing a climate warming scenario. Growth after 32 years from provenances transferred southward or northward over long distances was significantly lower than growth of local populations. All populations were affected by a severe natural drought event in 2002. The provenances from the most southern locations showed the highest drought tolerance but low productivity. Local provenances were productive and drought tolerant. Provenances from the boreal north showed lower productivity and less drought tolerance on southern test sites than all other sources, implying that maladaptation to drought may prevent boreal populations from taking full advantage of more favorable growing conditions under projected climate change. © 2015 John Wiley & Sons Ltd.

  1. Does inter-plant variation in sprouting time affect the growth/reproduction trade-off and herbivory in a tropical tree species?

    Directory of Open Access Journals (Sweden)

    Marcilio Fagundes

    Full Text Available ABSTRACT The timing of phenological events varies within and among populations, affecting the performance of individual plants differently. We evaluated the effects of relative variation in sprouting time on the display of reproductive events, vegetative growth and herbivory in Copaifera langsdorffii (Fabaceae. A total of 93 trees of C. langsdorffii was monitored daily to determine their sprouting time. We collected ten terminal branches of each plant to evaluate vegetative growth, production of defense compounds and insect herbivore damage. The sprouting time for the studied population lasted 67 days. Variation in sprouting time did not affect the probability of plants to enter the reproductive stage. Plants that entered the reproductive stage showed greater vegetative biomass. Variation in sprouting time had a negative relationship with branch growth and a positive relationship with the number of leaflets. Leaf phenol concentration did not vary in relation to sprouting time or plant phenology, but herbivory was higher in plants that sprouted later. The relationships among plant sprouting time, vegetative development and display of reproductive stage in C. langsdorffii are discussed. The results of this study also suggest that early sprouting prior to the rainy season is a strategy used by C. langsdorffii to escape herbivores attacks.

  2. Effect of a polybrominated diphenyl ether congener (BDE-47) on growth and antioxidative enzymes of two mangrove plant species, Kandelia obovata and Avicennia marina, in South China.

    Science.gov (United States)

    Wang, Ying; Zhu, Haowen; Tam, Nora Fung Yee

    2014-08-30

    The effects of BDE-47 on the growth and antioxidative responses of the seedlings of Kandelia obovata (Ko) and Avicennia marina (Am) were compared in an 8-week hydroponic culture spiked with different levels of BDE-47, 0.1, 1, 5 and 10 mg l(-1). The two highest BDE-47 levels significantly suppressed the growth and increased the activities of three antioxidative enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), of Ko in week 1. However, SOD and POD activities at high levels of BDE-47 became lower than the control in week 8. On the contrary, growth of Am was not affected at all contamination levels, and the activities of three enzymes were enhanced by BDE-47 in weeks 1 and 4, but such stimulatory effect became insignificant in week 8. Avicennia was more tolerant to BDE-47 toxicity than Kandelia, as its antioxidative enzymes could better counter-balance the oxidative stress caused by BDE-47. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Parallel evolution in an invasive plant species: evolutionary changes in allocation to growth, defense, competitive ability and regrowth of invasive Jacobaea vulgaris

    OpenAIRE

    Lin, Tiantian

    2015-01-01

    Although the introduction of invasive plant species in a given area causes economic and ecological problems, it still provides an ideal opportunity for ecologists to study evolutionary changes. According to the Evolution of Increased Competitive Ability hypothesis and Shifting Defense Hypothesis, the release from specialist herbivores after introduction is expected invasive plants to shift their costly defense against specialist herbivores to cheaper defense against local generalist herbivore...

  4. Germinação e crescimento de espécies de maracujá Germination and growth of passion fruit species

    Directory of Open Access Journals (Sweden)

    Adelise de Almeida Lima

    2006-04-01

    Full Text Available Objetivou-se, neste trabalho, avaliar a germinação e o índice de velocidade de emergência de cinco espécies de maracujazeiro para obtenção de plantas aptas ao processo de enxertia. O experimento foi conduzido em casa de vegetação da Embrapa Mandioca e Fruticultura Tropical, em Cruz das Almas (BA, no período de janeiro a junho de 2002. Foi utilizado o delineamento experimental inteiramente casualizado, e os tratamentos foram constituídos de: Passiflora edulis Sims f. flavicarpa Deg., Passiflora edulis Sims, Passiflora giberti N.E. Brown, Passiflora laurifolia L. e Passilfora alata Curtis, com quatro repetições e 25 plantas por parcela. As espécies constituíram cinco grupos diferentes para a variável índice de velocidade de emergência. No tocante à germinação, foram identificados dois grupos diferentes, um formado pelas espécies P. giberti e P. laurifolia e o outro, pelas demais espécies. Em termos de altura de planta, a espécie P. giberti apresentou a maior média, 40,40 cm, constituindo um grupo que é diferente das demais. As espécies P. edulis e P. edulis f. flavicarpa apresentaram melhores índices de velocidades de emergência e germinação e, conseqüentemente, as plantas obtidas mostraram-se aptas ao processo de enxertia em menor período de tempo.This work aimed to verify the germination and speed of emergence index of passion fruit species to obtain plants suitable for grafting. The experiment was carried out in a greenhouse at Embrapa Cassava and Tropical Fruits, in Cruz das Almas, BA from January to June, 2002. It was used a completely randomized design and the treatments were constituted of five passion fruit species: Passiflora edulis Sims f. flavicarpa Deg., Passiflora edulis Sims, Passiflora giberti N.E. Brown, Passiflora laurifolia L. and Passiflora alata Curtis, with four replications. The species constitute five different groups for the variable, speed of emergence index and, concerning to the

  5. Photoperiod cues and patterns of genetic variation limit phenological responses to climate change in warm parts of species' range: Modeling diameter-growth cessation in coast Douglas-fir.

    Science.gov (United States)

    Ford, Kevin R; Harrington, Constance A; St Clair, J Bradley

    2017-08-01

    The phenology of diameter-growth cessation in trees will likely play a key role in mediating species and ecosystem responses to climate change. A common expectation is that warming will delay cessation, but the environmental and genetic influences on this process are poorly understood. We modeled the effects of temperature, photoperiod, and seed-source climate on diameter-growth-cessation timing in coast Douglas-fir (an ecologically and economically vital tree) using high-frequency growth measurements across broad environmental gradients for a range of genotypes from different seed sources. Our model suggests that cool temperatures or short photoperiods can induce cessation in autumn. At cool locations (high latitude and elevation), cessation seems to be induced primarily by low temperatures in early autumn (under relatively long photoperiods), so warming will likely delay cessation and extend the growing season. But at warm locations (low latitude or elevation), cessation seems to be induced primarily by short photoperiods later in autumn, so warming will likely lead to only slight extensions of the growing season, reflecting photoperiod limitations on phenological shifts. Trees from seed sources experiencing frequent frosts in autumn or early winter tended to cease growth earlier in the autumn, potentially as an adaptation to avoid frost. Thus, gene flow into populations in warm locations with little frost will likely have limited potential to delay mean cessation dates because these populations already cease growth relatively late. In addition, data from an abnormal heat wave suggested that very high temperatures during long photoperiods in early summer might also induce cessation. Climate change could make these conditions more common in warm locations, leading to much earlier cessation. Thus, photoperiod cues, patterns of genetic variation, and summer heat waves could limit the capacity of coast Douglas-fir to extend its growing season in response to climate

  6. The influence of growth stimulants at different concentrations on ground seed germination and survival of seedlings of the main forest forming species of Central Siberia

    Directory of Open Access Journals (Sweden)

    M. A. Kirienko

    2016-02-01

    Full Text Available The influence of the growth stimulants with differences in active substance and concentrations on seed germination ability and seedlings safety of Scots pine (Pinus silvestris L., Siberian larch (Larix sibirica Ledeb., Siberian spruce (Picea obovata Ledeb. are studied. Studies have shown the reaction specificity of seed processing by growth stimulants. The increased concentration of Obereg stimulant (7 drops / 500 ml of water result in most significant positive impact on the seed field germination of Scots pine (at 31 % above control. The seedling safety is 30 % higher than the control at the same stimulant concentration. Seed treatment by stimulant Ekogel at concentrations of 20 ml/1 l of water and 30 ml/1 l of water result in increase of seed germination and seedlings safety. The extremely high concentration of Ekogel (40 ml/1 l of water authentically decreases as seed germination (on 21 %, and the seedlings safety (on 20 %. Ekogel stimulant is the best for seed germination of Siberian spruce, thus having a significant positive effect at all studied concentrations. Extreme concentrations of Heteroauxin (4 g/1 l of water also had a positive impact on the seed germination and seedling safety (20 and 15 % above the control respectively. Seed treatment of Siberian larch by a Novosil stimulant of high concentration (10 drops/1 l of water and Obereg stimulant (7 drops / 500 ml water has led to an increase in seed germination compared to controls at 26 and 25 % respectively. At the same concentrations of growth stimulants the highest seedlings safety (25 and 24 % above the control respectively was observed. Seed treatment by Ekogel stimulant at a concentration of 10 ml/1 l of water has led to a high seed germination ability and seedling safety. Higher concentrations of Ekogel stimulant (30 ml/1 liter of water and 40 ml/1 l of water significantly inhibit seed germination and reduce the seedling safety.

  7. Fecal microbial diversity in pre-weaned dairy calves as described by pyrosequencing of metagenomic 16S rDNA. Associations of Faecalibacterium species with health and growth.

    Directory of Open Access Journals (Sweden)

    Georgios Oikonomou

    Full Text Available In this study, we use barcoded pyrosequencing of the 16S rRNA gene to characterize the fecal microbiota of neonatal calves and identify possible relationships of certain microbiota profiles with health and weight gain. Fecal samples were obtained weekly from 61 calves from birth until weaning (seventh week of the calves' life. Firmicutes was the most prevalent phylum, with a prevalence ranging from 63.84% to 81.90%, followed by Bacteroidetes (8.36% to 23.93%, Proteobacteria (3.72% to 9.75%, Fusobacteria (0.76% to 5.67%, and Actinobacteria (1.02% to 2.35%. Chao1 index gradually increased from the first to the seventh postnatal week. Chao1 index was lower during the third, fourth, and fifth week of life in calves that suffered from pneumonia and were treated with antibiotics. Diarrhea incidence during the first four weeks of the calves' life was also associated with a reduction of microbial diversity during the third week of life. Increased fecal microbial diversity after the second week of life was associated with higher weight gain. Using discriminant analysis we were able to show differences in the microbiota profiles between different weeks of life, between high and low weight gain groups of calves, and between calves affected and not affected with diarrhea during the first four weeks life. The prevalence of Faecalibacterium spp. in the first week of life was associated with weight gain and the incidence of diarrhea, with higher prevalence being associated with higher weight gain and less diarrhea. Representative sequences from Faecalibacterium spp. were closely affiliated to Faecalibacterium prausnitzii. Results presented here provide new information regarding the intestinal microbiota of neonatal calves and its association with health and growth. Fecal microbial diversity was associated with calf age, disease status and growth rates. Results suggesting a possible beneficial effect of Faecalibacterium spp. on health and growth are promising.

  8. Comparison of growth of four tree species grown under agro-forestry systems. [Populus deltoides, Eucalyptus citriodora, Dalbergia sissoo, Salmalia malabrica

    Energy Technology Data Exchange (ETDEWEB)

    Sheikh, M.I.; Hussain, R.W.; Khan, M.

    1985-01-01

    Plants of Populus deltoides 1-63/51 and Eucalyptus citriodora, and cuttings of Dalbergia sissoo and Salmalia malabarica (Bombax malabaricum) were planted at 4X4m spacing in plots in Peshawar in February 1978. Sesamum indicum, maize and wheat were planted between tree rows. Height and diameter were recorded in December 1983. P. deltoides produced the best growth (av.ht. 21.1 m, av.d.b.h. 16.6cm) followed by B. malabaricum (av.ht. 19.8 m, av.d.b.h. 9.2cm).

  9. Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σB and the Blue-Light Sensor Lmo0799.

    Science.gov (United States)

    O'Donoghue, Beth; NicAogáin, Kerrie; Bennett, Claire; Conneely, Alan; Tiensuu, Teresa; Johansson, Jörgen; O'Byrne, Conor

    2016-07-01

    Listeria monocytogenes senses blue light via the flavin mononucleotide-containing sensory protein Lmo0799, leading to activation of the general stress response sigma factor SigB (σ(B)). In this study, we investigated the physiological response of this foodborne pathogen to blue light. We show that blue light (460 to 470 nm) doses of 1.5 to 2 mW cm(-2) cause inhibition of growth on agar-based and liquid culture media. The inhibitory effects are dependent on cell density, with reduced effects evident when high cell numbers are present. The addition of 20 mM dimethylthiourea, a scavenger of reactive oxygen species, or catalase to the medium reverses the inhibitory effects of blue light, suggesting that growth inhibition is mediated by the formation of reactive oxygen species. A mutant strain lacking σ(B) (ΔsigB) was found to be less inhibited by blue light than the wild type, likely indicating the energetic cost of deploying the general stress response. When a lethal dose of light (8 mW cm(-2)) was applied to cells, the ΔsigB mutant displayed a marked increase in sensitivity to light compared to the wild type. To investigate the role of the blue-light sensor Lmo0799, mutants were constructed that either had a deletion of the gene (Δlmo0799) or alteration in a conserved cysteine residue at position 56, which is predicted to play a pivotal role in the photocycle of the protein (lmo0799 C56A). Both mutants displayed phenotypes similar to the ΔsigB mutant in the presence of blue light, providing genetic evidence that residue 56 is critical for light sensing in L. monocytogenes Taken together, these results demonstrate that L. monocytogenes is inhibited by blue light in a manner that depends on reactive oxygen species, and they demonstrate clear light-dependent phenotypes associated with σ(B) and the blue-light sensor Lmo0799. Listeria monocytogenes is a bacterial foodborne pathogen that can cause life-threatening infections in humans. It is known to be able to

  10. Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σB and the Blue-Light Sensor Lmo0799

    Science.gov (United States)

    O'Donoghue, Beth; NicAogáin, Kerrie; Bennett, Claire; Conneely, Alan; Tiensuu, Teresa; Johansson, Jörgen

    2016-01-01

    ABSTRACT Listeria monocytogenes senses blue light via the flavin mononucleotide-containing sensory protein Lmo0799, leading to activation of the general stress response sigma factor SigB (σB). In this study, we investigated the physiological response of this foodborne pathogen to blue light. We show that blue light (460 to 470 nm) doses of 1.5 to 2 mW cm−2 cause inhibition of growth on agar-based and liquid culture media. The inhibitory effects are dependent on cell density, with reduced effects evident when high cell numbers are present. The addition of 20 mM dimethylthiourea, a scavenger of reactive oxygen species, or catalase to the medium reverses the inhibitory effects of blue light, suggesting that growth inhibition is mediated by the formation of reactive oxygen species. A mutant strain lacking σB (ΔsigB) was found to be less inhibited by blue light than the wild type, likely indicating the energetic cost of deploying the general stress response. When a lethal dose of light (8 mW cm−2) was applied to cells, the ΔsigB mutant displayed a marked increase in sensitivity to light compared to the wild type. To investigate the role of the blue-light sensor Lmo0799, mutants were constructed that either had a deletion of the gene (Δlmo0799) or alteration in a conserved cysteine residue at position 56, which is predicted to play a pivotal role in the photocycle of the protein (lmo0799 C56A). Both mutants displayed phenotypes similar to the ΔsigB mutant in the presence of blue light, providing genetic evidence that residue 56 is critical for light sensing in L. monocytogenes. Taken together, these results demonstrate that L. monocytogenes is inhibited by blue light in a manner that depends on reactive oxygen species, and they demonstrate clear light-dependent phenotypes associated with σB and the blue-light sensor Lmo0799. IMPORTANCE Listeria monocytogenes is a bacterial foodborne pathogen that can cause life-threatening infections in humans. It is known to

  11. The prolonged influence of growth stimulants on morphometric indicators of three-year seedlings of main forest forming species of Central Siberia

    Directory of Open Access Journals (Sweden)

    M. A. Kirienko

    2018-02-01

    Full Text Available The prolonged effects of growth stimulants with differences in active substance on morphometric parameters of three-year old seedlings of Scotch pine Pinus silvestris L., Siberian spruce Picea obovata Ledeb., Siberian larch Larix sibirica Ledeb., whose seeds had been treated with growth substances were studied. Analyzing a set of indicators: seed germination, seedling safety, height and diameter of trunks at root collar of 3-year-old seedlings in the forest-steppe zone of the Krasnoyarsk territory the reaction specificity of coniferous seedlings to seeds pre-plant processing are stated. It was found that height, height increment and stem diameter of Scots pine seedlings whose seeds were treated with stimulants Obereg’, Zircon, Epin-extra, Ecogel were significantly higher than seedlings under control. Seedling height and height increment of Siberian spruce seeds, which were processed by the stimulant Epin-extra were significantly more than the same under control. In addition to Epin-extra, Zircon and Heteroauxin stimulants had a positive effect on Siberian spruce seedling stem diameter. Siberian larch seeds treatment by all stimulants except Immunotsitofit, had a positive impact on the height and diameter of stem 3-year-old seedlings. The highest stem diameter was observed in seedlings whose seeds were treated with Ecogel and Heteroauxin stimulants. All stimulants had a significant positive effect (1.5–2 times higher compared to control on the current linear increments.

  12. Effect of Antioxidant Mixtures on Growth and Ochratoxin A Production of Aspergillus Section Nigri Species under Different Water Activity Conditions on Peanut Meal Extract Agar

    Directory of Open Access Journals (Sweden)

    Carla Barberis

    2010-06-01

    Full Text Available The effect of mixtures of antioxidants butylated hydroxyanisol (BHA and propyl paraben (PP on lag phase, growth rate and ochratoxin A (OTA production by four Aspergillus section Nigri strains was evaluated on peanut meal extract agar (PMEA under different water activities (aw. The antioxidant mixtures used were: BHA + PP (mM, M1 (0.5 + 0.5, M2 (1.0 + 0.5, M3 (2.5 + 0.5, M4 (0.5 + 1.0, M5 (1.0 + 1.0, M6 (2.5 + 1.0, M7 (5.0 + 2.5 and M8 (10 + 2.5. The mixture M8 completely suppressed mycelial growth for all strains. A significant stimulation in OTA production was observed with mixtures M1 to M5 mainly at the highest aw; whereas M6, M7 and M8 completely inhibited OTA production in all strains assayed; except M6 in A. carbonarius strain (RCP G. These results could enable a future intervention strategy to minimize OTA contamination.

  13. Radiation-induced pollen germination, tube growth, its localized cytochemical constituents, fruit set and fruit size in alkaloid yielding species Solanum torvum L

    International Nuclear Information System (INIS)

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

    1990-01-01

    The volume of pollen, total number of pollen/flower, the percent of pollen germination and tube growth of long-styled flower were higher than the short-styled flowers in S. torvum. In addition, the pollination studies were conducted among the four selected sets for optimum fruit set investigation. Fruit set was not seen in both the first and second sets (female shorts-short male and female short-long male). However, the maximum fruit set was obtained in the fourth set (female long-male long). Pollen grains of long-styled flowers irradiated with 1-800 krad were germinated in the basal medium. The percent of pollen germination and the tube growth was stimulated over the control with 1 and 50 krad dose exposures, but increasing dose rates inhibited both the above processes. Utilization of insoluble polysaccharides, and the synthesis of RNA and protein were enhanced over the control with the effect of 50 krad. The higher (800 krad) dose exposures inhibited all the above cytochemical constituents. Various dose-treated pollens were used to pollinate the stigma surface of the long-styled flowers. The fruit set, fruit volume, fresh and dry weight of fruits, and the number of seed set/fruit, were enhanced over the control by 1 and 50 krad, while the higher doses caused inhibitory effect. Interestingly, the fruit set was not caused by radiation doses 400 krad and above. (author)

  14. Two-dimensional fluorescence in-gel electrophoresis of coronary restenosis tissues in minipigs: increased adipocyte fatty acid binding protein induces reactive oxygen species-mediated growth and migration in smooth muscle cells.

    Science.gov (United States)

    Lu, Lin; Wang, Ya Nan; Sun, Wei Hua; Liu, Zhu Hui; Zhang, Qi; Pu, Li Jin; Yang, Ke; Wang, Ling Jie; Zhu, Zhen Bin; Meng, Hua; Yang, Ping; Du, Run; Chen, Qiu Jing; Wang, Li Shun; Yu, Hong; Shen, Wei Feng

    2013-03-01

    We aimed to uncover the protein changes of coronary artery in-stent restenosis (ISR) tissue in minipigs with and without streptozotocin-induced diabetes mellitus by quantitative 2-dimensional fluorescence in-gel electrophoresis (2D-DIGE), and to investigate the influences of crucial proteins identified, particularly adipocyte fatty acid binding protein (AFABP), in human arterial smooth muscle cells. Sirolimus-eluting stents were implanted in the coronary arteries of 15 diabetic and 26 nondiabetic minipigs, and angiography was repeated after 6 months. The intima tissue of significant ISR and non-ISR segments in both diabetic and nondiabetic minipigs was analyzed by 2D-DIGE and MALDI-TOF/TOF mass spectrometry. AFABP level was significantly increased in ISR tissue than in non-ISR tissue in both diabetic and nondiabetic minipigs, with level being higher in diabetic ISR than in nondiabetic ISR tissue. In human arterial smooth muscle cells, overexpression of AFABP significantly altered phenotype and promoted growth and migration, with effects more prominent in high-glucose than in low-glucose medium, whereas AFABP knockdown inhibited these effects. AFABP overexpression increased reactive oxygen species production by upregulating the expression of NADPH oxidase subunits Nox1, Nox4, and P22 through multiple pathways, with elevation of downstream gene cyclin D1, matrix metalloproteinase-2, and monocyte chemoattractant protein-1. However, AFABP-induced effects were inhibited by diphenyleneiodonium, pathway inhibitors, and small interfering RNA. In addition, the supernatant from AFABP-expressing human arterial smooth muscle cells and recombinant AFABP also promoted cellular growth and migration. This study has demonstrated that AFABP is significantly increased in coronary artery ISR segments of both diabetic and nondiabetic minipigs. Increased AFABP expression and secretory AFABP of human arterial smooth muscle cells promote growth and migration via reactive oxygen species

  15. Growth Rates, Stable Oxygen Isotopes (18O), and Strontium (Sr/Ca) Composition in Two Species of Pacific Sclerosponges (Acanthocheatetes wellsi and Astrosclera willeyana) with 18O Calibration and Application to Paleoceanography

    Energy Technology Data Exchange (ETDEWEB)

    Grottoli, A.; Adkins, J; Panero, W; Reaman, D; Moots, K

    2010-01-01

    The isotopic and elemental composition of sclerosponge skeletons is used to reconstruct paleoceanographic records. Yet few studies have systematically examined the natural variability in sclerosponge skeletal {delta}{sup 18}O, growth, and Sr/Ca, and how that may influence the interpretation of sclerosponge proxy records. Here, we analyzed short records in seven specimens of Acanthocheatetes wellsi (high-Mg calcite, 21 mol% Mg) from Palau, four A. wellsi (high-Mg calcite, 21 mol% Mg) from Saipan, and three Astrosclera willeyana (aragonite) sclerosponges from Saipan, as well as one long record in an A. wellsi specimen from Palau spanning 1945-2001.5. In Saipan, species-specific and mineralogical effects appear to have a negligible effect on sclerosponge {delta}{sup 18}O, facilitating the direct comparison of {delta}{sup 18}O records between species at a given location. At both sites, A. wellsi {delta}{sup 18}O and growth rates were sensitive to environmental conditions, but Sr/Ca was not sensitive to the same conditions. High-resolution {delta}{sup 18}O analyses confirmed this finding as both A. wellsi and A. willeyana deposited their skeleton in accordance with the trends in isotopic equilibrium with seawater, though with a 0.27{per_thousand} offset in the case of A. willeyana. In the high-Mg-calcite species A. wellsi, Mg may be interfering with Sr incorporation into the skeleton. On multidecadal timescales, A. wellsi sclerosponge {delta}{sup 18}O in Palau tracked the Southern Oscillation Index variability post-1977, but not pre-1977, coincident with the switch in the Pacific Decadal Oscillation (PDO) at {approx}1976. This suggests that water mass circulation in the region is influenced by El Nino-Southern Oscillation variability during positive PDO phases, but not during negative ones.

  16. The composition and depth of green roof substrates affect the growth of Silene vulgaris and Lagurus ovatus species and the C and N sequestration under two irrigation conditions.

    Science.gov (United States)

    Ondoño, S; Martínez-Sánchez, J J; Moreno, J L

    2016-01-15

    Extensive green roofs are used to increase the surface area covered by vegetation in big cities, thereby reducing the urban heat-island effect, promoting CO2 sequestration, and increasing biodiversity and urban-wildlife habitats. In Mediterranean semi-arid regions, the deficiency of water necessitates the use in these roofs of overall native plants which are more adapted to drought than other species. However, such endemic plants have been used scarcely in green roofs. For this purpose, we tested two different substrates with two depths (5 and 10 cm), in order to study their suitability with regard to adequate plant development under Mediterranean conditions. A compost-soil-bricks (CSB) (1:1:3; v:v:v) mixture and another made up of compost and bricks (CB) (1:4; v:v) were arranged in two depths (5 and 10 cm), in cultivation tables. Silene vulgaris (Moench) Garcke and Lagurus ovatus L. seeds were sown in each substrate. These experimental units were subjected, on the one hand, to irrigation at 40% of the registered evapotranspiration values (ET0) and, on the other, to drought conditions, during a nine-month trial. Physichochemical and microbiological substrate characteristics were studied, along with the physiological and nutritional status of the plants. We obtained significantly greater plant coverage in CSB at 10 cm, especially for L. ovatus (80-90%), as well as a better physiological status, especially in S. vulgaris (SPAD values of 50-60), under irrigation, whereas neither species could grow in the absence of water. The carbon and nitrogen fixation by the substrate and the aboveground biomass were also higher in CSB at 10 cm, especially under L. ovatus - in which 1.32 kg C m(-2) and 209 g N m(-2) were fixed throughout the experiment. Besides, the enzymatic and biochemical parameters assayed showed th