WorldWideScience

Sample records for growth factor-affinity-labeled species

  1. Clonal growth and plant species abundance.

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-08-01

    Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf-height-seed) traits and by actual performance in the botanical garden. Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area - height - seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially underlying clonal growth effects on abundance. Garden

  2. Species Diversity Enhances Predator Growth Rates

    International Nuclear Information System (INIS)

    Olson, M.H.; Jacobs, R.P.; O'Donnell, E.B.

    2007-01-01

    Predators can be important top-down regulators of community structure and are known to have both positive and negative effects on species diversity. However, little is known about the reciprocal effects of species diversity on predators. Across a set of 80 lakes in Connecticut, USA, we found a strong positive correlation between prey species diversity (using the Shannon-Weiner Diversity Index) and growth rates of largemouth bass (Micropterus salmoides). This correlation was strongest for small predators and decreased with body size. Although the underlying mechanisms are not known, the correlation is not driven by total fish abundance, predator abundance, or productivity.

  3. 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

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

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... A field study compared the seedling emergence and structure of five forage legumes .... mean seed mass (without seed coat) per species was used for W1 ...... Of light and length: regulation of hypocotyl growth in Arabidopsis.

  5. 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. Ameri...

  6. Seedling growth strategies in Bauhinia species: comparing lianas and trees

    NARCIS (Netherlands)

    Cai, Z.Q.; Poorter, L.; Cao, K.F.; Bongers, F.J.J.M.

    2007-01-01

    Background and Aims: Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass

  7. 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,

  8. Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees

    Science.gov (United States)

    Cai, Zhi-Quan; Poorter, Lourens; Cao, Kun-Fang; Bongers, Frans

    2007-01-01

    Background and Aims Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass allocation and leaf traits in five closely related liana and tree species of the genus Bauhinia. Methods Seedlings of two light-demanding lianas (Bauhinia tenuiflora and B. claviflora), one shade-tolerant liana (B. aurea), and two light-demanding trees (B. purpurea and B. monandra) were grown in a shadehouse at 25 % of full sunlight. A range of physiological, morphological and biomass parameters at the leaf and whole plant level were compared among these five species. Key Results The two light-demanding liana species had higher relative growth rate (RGR), allocated more biomass to leaf production [higher leaf mass fraction (LMF) and higher leaf area ratio (LAR)] and stem mass fraction (SMF), and less biomass to the roots [root mass fraction (RMF)] than the two tree species. The shade-tolerant liana had the lowest RGR of all five species, and had a higher RMF, lower SMF and similar LMF than the two light-demanding liana species. The two light-demanding lianas had lower photosynthetic rates per unit area (Aarea) and similar photosynthetic rates per unit mass (Amass) than the trees. Across species, RGR was positively related to SLA, but not to LAR and Aarea. Conclusions It is concluded that the faster growth of light-demanding lianas compared with light-demanding trees is based on morphological parameters (SLA, LMF and LAR), and cannot be attributed to higher photosynthetic rates at the leaf level. The shade-tolerant liana exhibited a slow-growth strategy, compared with the light-demanding species. PMID:17720978

  9. Tree-growth analyses to estimate tree species' drought tolerance.

    Science.gov (United States)

    Eilmann, Britta; Rigling, Andreas

    2012-02-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.

  10. 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.

  11. 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.

  12. Tree-growth analyses to estimate tree species' drought tolerance

    NARCIS (Netherlands)

    Eilmann, B.; Rigling, A.

    2012-01-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree

  13. 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.

  14. 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 ...

  15. 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)

  16. 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.

  17. 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 mixtur...... producing beta-glucosidase and endoglucanases. Xylose did not repress the enzyme production and it induced the production of endoxylanases and beta-xylosidases....

  18. Growth parameters influencing uptake of chlordecone by Miscanthus species.

    Science.gov (United States)

    Liber, Yohan; Létondor, Clarisse; Pascal-Lorber, Sophie; Laurent, François

    2018-05-15

    Because of its high persistence in soils, t 1/2 =30years, chlordecone (CLD) was classified as a persistent organic pollutant (POP) by the Stockholm Convention in 2009.The distribution of CLD over time has been heterogeneous, ranging from banana plantations to watersheds, and contaminating all environmental compartments. The aims of this study were to (i) evaluate the potential of Miscanthus species to extract chlordecone from contaminated soils, (ii) identify the growth parameters that influence the transfer of CLD from the soil to aboveground plant parts. CLD uptake was investigated in two species of Miscanthus, C4 plants adapted to tropical climates. M. sinensis and M.×giganteus were transplanted in a soil spiked with [ 14 C]CLD at environmental concentrations (1mgkg -1 ) under controlled conditions. Root-shoot transfer of CLD was compared in the two species after two growing periods (2 then 6months) after transplantation. CLD was found in all plant organs, roots, rhizomes, stems, leaves, and even flower spikes. The highest concentration of CLD was in the roots, 5398±1636 (M.×giganteus) and 14842±3210ngg -1 DW (M. sinensis), whereas the concentration in shoots was lower, 152±28 (M.×giganteus) and 266±70ngg -1 DW (M. sinensis) in soil contaminated at 1mgkg -1 . CLD translocation led to an acropetal gradient from the bottom to the top of the plants. CLD concentrations were also monitored over two complete growing periods (10months) in M. sinensis grown in 8.05mgkg -1 CLD contaminated soils. Concentrations decreased in M. sinensis shoots after the second growth period due to the increase in organic matters in the vicinity of the roots. Results showed that, owing to their respective biomass production, the two species were equally efficient at phytoextraction of CLD. Copyright © 2017. Published by Elsevier B.V.

  19. 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.

  20. 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)

  1. Environmental effects on growth phenology of co-occurring Eucalyptus species.

    Science.gov (United States)

    Rawal, Deepa S; Kasel, Sabine; Keatley, Marie R; Aponte, Cristina; Nitschke, Craig R

    2014-05-01

    Growth is one of the most important phenological cycles in a plant's life. Higher growth rates increase the competitive ability, survival and recruitment and can provide a measure of a plant's adaptive capacity to climate variability and change. This study identified the growth relationship of six Eucalyptus species to variations in temperature, soil moisture availability, photoperiod length and air humidity over 12 months. The six species represent two naturally co-occurring groups of three species each representing warm-dry and the cool-moist sclerophyll forests, respectively. Warm-dry eucalypts were found to be more tolerant of higher temperatures and lower air humidity than the cool-moist eucalypts. Within groups, species-specific responses were detected with Eucalyptus microcarpa having the widest phenological niche of the warm-dry species, exhibiting greater resistance to high temperature and lower air humidity. Temperature dependent photoperiodic responses were exhibited by all the species except Eucalyptus tricarpa and Eucalyptus sieberi, which were able to maintain growth as photoperiod shortened but temperature requirements were fulfilled. Eucalyptus obliqua exhibited a flexible growth rate and tolerance to moisture limitation which enables it to maintain its growth rate as water availability changes. The wider temperature niche exhibited by E. sieberi compared with E. obliqua and Eucalyptus radiata may improve its competitive ability over these species where winters are warm and moisture does not limit growth. With climate change expected to result in warmer and drier conditions in south-east Australia, the findings of this study suggest all cool-moist species will likely suffer negative effects on growth while the warm-dry species may still maintain current growth rates. Our findings highlight that climate driven shifts in growth phenology will likely occur as climate changes and this may facilitate changes in tree communities by altering inter

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

    African Journals Online (AJOL)

    The seeds were collected from home gardens in Benin City and NIHORT. ... crude oil contamination of soil may lead to reduction in growth characteristics. Keywords: Crude oil, Soil, ..... Review of Botanical Applications in Tropical Agriculture,.

  3. Pseudomonas aeruginosa inhibits the growth of Cryptococcus species.

    Science.gov (United States)

    Rella, Antonella; Yang, Mo Wei; Gruber, Jordon; Montagna, Maria Teresa; Luberto, Chiara; Zhang, Yong-Mei; Del Poeta, Maurizio

    2012-06-01

    Pseudomonas aeruginosa is a ubiquitous and opportunistic bacterium that inhibits the growth of different microorganisms, including Gram-positive bacteria and fungi such as Candida spp. and Aspergillus fumigatus. In this study, we investigated the interaction between P. aeruginosa and Cryptococcus spp. We found that P. aeruginosa PA14 and, to a lesser extent, PAO1 significantly inhibited the growth of Cryptococcus spp. The inhibition of growth was observed on solid medium by the visualization of a zone of inhibition of yeast growth and in liquid culture by viable cell counting. Interestingly, such inhibition was only observed when P. aeruginosa and Cryptococcus were co-cultured. Minimal inhibition was observed when cell-cell contact was prevented using a separation membrane, suggesting that cell contact is required for inhibition. Using mutant strains of Pseudomonas quinoline signaling, we showed that P. aeruginosa inhibited the growth of Cryptococcus spp. by producing antifungal molecules pyocyanin, a redox-active phenazine, and 2-heptyl-3,4-dihydroxyquinoline (PQS), an extracellular quorum-sensing signal. Because both P. aeruginosa and Cryptococcus neoformans are commonly found in lung infections of immunocompromised patients, this study may have important implication for the interaction of these microbes in both an ecological and a clinical point of view.

  4. 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.

  5. 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. ...

  6. 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 ...

  7. 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.

  8. 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 ...

  9. 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 ...

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

    OpenAIRE

    Tooba Abedi; Shamim Moghaddami; Ebrahim Lashkar Bolouki

    2014-01-01

    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....

  11. 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

  12. 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.

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

    DEFF Research Database (Denmark)

    Huang, Weiwei

    and high temperatures on the development of Danish tree species are scarcely investigated. Through a dendroecological approach this dissertation assessed the growth responses related to increment, xylem anatomy and wood property of eight different important tree species, namely Picea abies (L.) Karst......., Picea sitchensis (Bong.) Carr., Abies alba Mill., Abies grandis (Dougl.) Lindl., Pseudotsuga mensiesii (Mirb.) Franco, Larix kaempferi (Lamb.) Carr., Quercus robur L. and Fagus sylvatica L., to long-term drought and high temperatures, aiming at identifying a species portfolio matching future climate...... intolerant species, mainly due to their low drought tolerance (both species) and susceptibility to high autumn temperature (only P. abies). Overall, this dissertation improves the understanding of how drought and high temperatures have impacted and will influence the growth of tree species in Danish forest...

  14. 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...

  15. 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...

  16. Growth of 11 introduced tree species on selected forest sites in Hawaii

    Science.gov (United States)

    Michael G Buck; Roger H. Imoto

    1982-01-01

    Growth and volume data for trees on 25 plots reprsenting 11 introduced species in Hawaii were recorded during a 21-year period. Tree were measured at about 5-year intervals to determine overall growth and stand development. The sites selected were considered better-than-average in terms of elevation, amount of precipitation, and soil quality. Except for redwood, stands...

  17. Summer droughts limit tree growth across 10 temperate species on a productive forest site

    NARCIS (Netherlands)

    Weemstra, M.; Eilmann, B.; Sass-Klaassen, U.; Sterck, F.J.

    2013-01-01

    Studies on climate impacts on tree annual growth are mainly restricted to marginal sites. To date, the climate effects on annual growth of trees in favorable environments remain therefore unclear despite the importance of these sites in terms of forest productivity. Because species respond

  18. Agroforestry systems of timber species and cacao: survival and growth during the early stages

    Directory of Open Access Journals (Sweden)

    Wilmer Espinoza

    2013-08-01

    Full Text Available In recent times, increased emphasis has been placed on diversifying the types of trees to shade cacao (Theobromacacao L. and to achieve additional services. Agroforestry systems that include profitable and native timber trees are a viable alternative but it is necessary to understand the growth characteristics of these species under different environmental conditions. Thus, timber tree species selection should be based on plant responses to biotic and abiotic factors. The aims of this study were (1 to evaluate growth rates and leaf area indices of the four commercial timber species: Cordia thaisiana, Cedrela odorata, Swietenia macrophylla and Tabebuia rosea in conjunction with incidence of insect attacks and (2 to compare growth rates of four Venezuelan Criollo cacao cultivars planted under the shade of these four timber species during the first 36 months after establishment. Parameters monitored in timber trees were: survival rates, growth rates expressed as height and diameter at breast height and leaf area index. In the four Cacao cultivars: height and basal diameter. C. thaisiana and C. odorata had the fastest growth and the highest survival rates. Growth rates of timber trees will depend on their susceptibility to insect attacks as well as to total leaf area. All cacao cultivars showed higher growth rates under the shade of C. odorata. Growth rates of timber trees and cacao cultivars suggest that combinations of cacao and timber trees are a feasible agroforestry strategy in Venezuela.

  19. Growth of four species of the forest marshes of the Colombian pacific coast

    International Nuclear Information System (INIS)

    Del Valle Arango, Jorge Ignacio

    1997-01-01

    During 12 years, growth in diameter of Otoba gracilipes (cuangare), eugenia spp. (Guayabillo), Swartzia amplifolia var rigida (Cuna) and Pithecellobium latifolium (Pinde) was studied in guandal and cuangarial associations in the delta of the Patia River. For these species of the under story, the subcanopy and the canopy, models of growth were established using von Bertalanffy's model in four forms. Equations of growth in diameter were obtained for four variables, which are discussed critically

  20. Comparative Study of Worldwide Species of Genus Lentinus (=Lentinula, Higher Basidiomycetes) Based on Linear Mycelium Growth.

    Science.gov (United States)

    Mata, Juan Luis; Mishra, Nutan Tulapurkar

    2015-01-01

    Species of mushroom genus Lentinus (=Lentinula) are best known for the commercially important and extensively studied culinary-medicinal shiitake, L. edodes. A few mycelium growth studies have focused on Lentinus boryana, but information is lacking for L. raphanica and L. aciculospora, endemic to the Americas. In this study, 14 dikaryon strains representing 5 Lentinus species were grown on 5 nutritive agar media at increments of 5°C. Growth for each species was significantly slower on corn meal agar, but no differences were found among malt extract, potato dextrose, malt peptone, and yeast malt extract agars. Lentinus aciculospora and L. boryana consistently exhibited the slowest mycelium growth rates among all species and across all temperatures tested, with optima at 15°C and 20°C. The fastest mycelium growth rates for L. edodes, L. novaezelandiae, and L. raphanica occurred at 25°C. Strains of the latter continued to grow well at 30°C, whereas growth of the other 2 species declined significantly. Differences in mycelium growth rates for American strains could be partially explained by their geographic locations, indicating that understanding this physiological parameter has important ramifications for the edible mushroom industry.

  1. Remnant trees affect species composition but not structure of tropical second-growth forest.

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

  2. 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.

  3. 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.

  4. 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.

  5. Carbon allocation to growth and storage in two evergreen species of contrasting successional status.

    Science.gov (United States)

    Piper, Frida I; Sepúlveda, Paulina; Bustos-Salazar, Angela; Zúñiga-Feest, Alejandra

    2017-05-01

    A prevailing hypothesis in forest succession is that shade-tolerant species grow more slowly than shade-intolerant species, across light conditions, because they prioritize carbon (C) allocation to storage. We examined this hypothesis in a confamilial pair of species, including one of the fastest-growing tree species in the world ( Eucalyptus globulus ) and a shade-tolerant, slow-growing species ( Luma apiculata ). Seedlings were subjected to one out of four combinations of light (high vs. low) and initial defoliation (90% defoliated vs. nondefoliated) for four months. Growth, C storage concentration in different organs, leaf shedding, and lateral shoot formation were measured at the end of the experiment. Eucalyptus globulus grew faster than L. apiculata in high light, but not in low light. Both species had lower C storage concentration in low than in high light, but similar C storage concentrations in each light condition. Defoliation had no effect on C storage, except in the case of the old leaves of both species, which showed lower C storage levels in response to defoliation. Across treatments, leaf shedding was 96% higher in E. globulus than in L. apiculata while, in contrast, lateral shoot formation was 87% higher in L. apiculata . In low light, E. globulus prioritized C storage instead of growth, whereas L. apiculata prioritized growth and lateral branching. Our results suggest that shade tolerance depends on efficient light capture rather than C conservation traits. © 2017 Botanical Society of America.

  6. 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.

  7. Physiological minimum temperatures for root growth in seven common European broad-leaved tree species.

    Science.gov (United States)

    Schenker, Gabriela; Lenz, Armando; Körner, Christian; Hoch, Günter

    2014-03-01

    Temperature is the most important factor driving the cold edge distribution limit of temperate trees. Here, we identified the minimum temperatures for root growth in seven broad-leaved tree species, compared them with the species' natural elevational limits and identified morphological changes in roots produced near their physiological cold limit. Seedlings were exposed to a vertical soil-temperature gradient from 20 to 2 °C along the rooting zone for 18 weeks. In all species, the bulk of roots was produced at temperatures above 5 °C. However, the absolute minimum temperatures for root growth differed among species between 2.3 and 4.2 °C, with those species that reach their natural distribution limits at higher elevations also tending to have lower thermal limits for root tissue formation. In all investigated species, the roots produced at temperatures close to the thermal limit were pale, thick, unbranched and of reduced mechanical strength. Across species, the specific root length (m g(-1) root) was reduced by, on average, 60% at temperatures below 7 °C. A significant correlation of minimum temperatures for root growth with the natural high elevation limits of the investigated species indicates species-specific thermal requirements for basic physiological processes. Although these limits are not necessarily directly causative for the upper distribution limit of a species, they seem to belong to a syndrome of adaptive processes for life at low temperatures. The anatomical changes at the cold limit likely hint at the mechanisms impeding meristematic activity at low temperatures.

  8. 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.

  9. 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.

  10. Evaluating of Physiological Indices of Weed Species at Different Density on Corn (Zea mays L. Growth

    Directory of Open Access Journals (Sweden)

    Gh Mahmodi

    2014-07-01

    Full Text Available Crop density is one of the usage tools in sustainable agriculture to carry out integrated weed management. Weed species response varied according to diversity and density of species in agricultural ecosystems. This study was conducted in research field of Ferdowsi University of Mashhad, Iran. Four levels of corn densities (5, 6, 7 and 9 plant m-2 and four levels of species diversity were used including complete control, broad leaved control (corn and narrow leaves, grass control (corn and broad leaves and without control (corn, broadleaves and grass weeds by weeding. All species sampling were done at five stages from 42 days after planting up to the end of growth period. Crop growth rate, total dry matter of weed (TDMw and total dry matter of corn (TDMc were measured. Results showed that TDMc was minimum at 9 and 5 plant m-2 in the early growth period, while it was highest at 9 plant m-2 by the end of the growth period. Also, TDMc increased with increasing density in the weed free control, but (TDMc decreased about 46% in compare with complete control. The same trends were observed for CGR. It was found that broad leaves weeds were more effective than narrow leaves (causing 60 and 34% lower CGR reduction, respectively on corn growth.

  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 to evaluate the growth potential of the unimproved Australian species and the improved commercial controls incorporated into the trials. Volume production and basal area growth were assessed for the three species at all sites. However, only three sub species E...

  12. 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

    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...... in the marine carbon cycle....... 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...

  13. Transplantation experiments with Caribbean Millepora species (Hydrozoa, Coelenterata), including some ecological observations on growth forms

    OpenAIRE

    Weerdt, de, Wallie H.

    1981-01-01

    The historical background of the taxonomic problems in the fire-coral, Millepora, is reviewed. The growth forms of the Caribbean species: Millepora alcicornis Linnaeus, M. complanata Lamarck and M. squarrosa Lamarck are investigated in relation with environmental factors: water movement, current, light and turbidity. Several sites on Curaçao and Bonaire were visited and all forms of Millepora collected. The localities have been divided in biotopes and the relative frequencies of the growth fo...

  14. 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.

  15. Some aspects of the Seed Germination and Seedling Growth of two Savanna tree Species

    OpenAIRE

    D.A. Agboola; A.A. Ajiboye; O.O. Fawibe; M.O. Atayese

    2014-01-01

    Studies were made on some aspects of the seed germination and seedling growth of two multipurpose trees. These include the effect of pre sowing treatments, seed sizes and gibberellic acid on the germination of seeds and seedling growth. The tree species include Prosopis africana (Guil & Perr) Taub and Dialium guineense (wild). Two seed sizes designated small- size (Ss) and Big-size (Bs) were identified in the seed. The effect of gibberellic acid (GA3) had a greater significance effect (P < 0....

  16. 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

    2013-01-01

    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. Copyright © 2012 Wiley Periodicals, Inc.

  17. 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.

  18. Mapping forest structure, species gradients and growth in an urban area using lidar and hyperspectral imagery

    Science.gov (United States)

    Gu, Huan

    Urban forests play an important role in the urban ecosystem by providing a range of ecosystem services. Characterization of forest structure, species variation and growth in urban forests is critical for understanding the status, function and process of urban ecosystems, and helping maximize the benefits of urban ecosystems through management. The development of methods and applications to quantify urban forests using remote sensing data has lagged the study of natural forests due to the heterogeneity and complexity of urban ecosystems. In this dissertation, I quantify and map forest structure, species gradients and forest growth in an urban area using discrete-return lidar, airborne imaging spectroscopy and thermal infrared data. Specific objectives are: (1) to demonstrate the utility of leaf-off lidar originally collected for topographic mapping to characterize and map forest structure and associated uncertainties, including aboveground biomass, basal area, diameter, height and crown size; (2) to map species gradients using forest structural variables estimated from lidar and foliar functional traits, vegetation indices derived from AVIRIS hyperspectral imagery in conjunction with field-measured species data; and (3) to identify factors related to relative growth rates in aboveground biomass in the urban forests, and assess forest growth patterns across areas with varying degree of human interactions. The findings from this dissertation are: (1) leaf-off lidar originally acquired for topographic mapping provides a robust, potentially low-cost approach to quantify spatial patterns of forest structure and carbon stock in urban areas; (2) foliar functional traits and vegetation indices from hyperspectral data capture gradients of species distributions in the heterogeneous urban landscape; (3) species gradients, stand structure, foliar functional traits and temperature are strongly related to forest growth in the urban forests; and (4) high uncertainties in our

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Transplantation experiments with Caribbean Millepora species (Hydrozoa, Coelenterata), including some ecological observations on growth forms

    NARCIS (Netherlands)

    Weerdt, de Wallie H.

    1981-01-01

    The historical background of the taxonomic problems in the fire-coral, Millepora, is reviewed. The growth forms of the Caribbean species: Millepora alcicornis Linnaeus, M. complanata Lamarck and M. squarrosa Lamarck are investigated in relation with environmental factors: water movement, current,

  4. 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...

  5. 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.

  6. 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

  7. [Effects of waterlogging on the growth and energy-metabolic enzyme activities of different tree species].

    Science.gov (United States)

    Wang, Gui-Bin; Cao, Fu-Liang; Zhang, Xiao-Yan; Zhang, Wang-Xiang

    2010-03-01

    Aimed to understand the waterlogging tolerance and adaptation mechanisms of different tree species, a simulated field experiment was conducted to study the growth and energy-metabolic enzyme activities of one-year-old seedlings of Taxodium distichum, Carya illinoensis, and Sapium sebiferum. Three treatments were installed, i. e., CK, waterlogging, and flooding, with the treatment duration being 60 days. Under waterlogging and flooding, the relative growth of test tree species was in the order of T. distichum > C. illinoensis > S. sebiferum, indicating that T. distichum had the strongest tolerance against waterlogging and flooding, while S. sebiferum had the weakest one. Also under waterlogging and flooding, the root/crown ratio of the three tree species increased significantly, suggesting that more photosynthates were allocated in roots, and the lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) activities of the tree species also had a significant increase. Among the test tree species, T. distichum had the lowest increment of LDH and ADH activities under waterlogging and flooding, but the increment could maintain at a higher level in the treatment duration, while for C. illinoensis and S. sebiferum, the increment was larger during the initial and medium period, but declined rapidly during the later period of treatment. The malate dehydrogenase (MDH), phosphohexose (HPI), and glucose-6-phosphate dehydrogenase (G6PDH) -6-phosphogluconate dehydrogenase (6PGDH) activities of the tree species under waterlogging and flooding had a significant decrease, and the decrement was the largest for T. distichum, being 35.6% for MDH, 21.0% for HPI, and 22.7% for G6PDH - 6PGDH under flooding. It was suggested that under waterlogging and flooding, the tree species with strong waterlogging tolerance had a higher ability to maintain energy-metabolic balance, and thus, its growth could be maintained at a certain level.

  8. Canopy gradients in leaf functional traits for species that differ in growth strategies and shade tolerance.

    Science.gov (United States)

    Coble, Adam P; Fogel, Marilyn L; Parker, Geoffrey G

    2017-10-01

    In temperate deciduous forests, vertical gradients in leaf mass per area (LMA) and area-based leaf nitrogen (Narea) are strongly controlled by gradients in light availability. While there is evidence that hydrostatic constraints on leaf development may diminish LMA and Narea responses to light, inherent differences among tree species may also influence leaf developmental and morphological response to light. We investigated vertical gradients in LMA, Narea and leaf carbon isotope composition (δ13C) for three temperate deciduous species (Carpinus caroliniana Walter, Fagus grandifolia Ehrh., Liriodendron tulipifera L.) that differed in growth strategy (e.g., indeterminate and determinate growth), shade tolerance and leaf area to sapwood ratio (Al:As). Leaves were sampled across a broad range of light conditions within three vertical layers of tree crowns to maximize variation in light availability at each height and to minimize collinearity between light and height. All species displayed similar responses to light with respect to Narea and δ13C, but not for LMA. Light was more important for gradients in LMA for the shade-tolerant (C. caroliniana) and -intolerant (L. tulipifera) species with indeterminate growth, and height (e.g., hydrostatic gradients) and light were equally important for the shade-tolerant (F. grandifolia) species with determinate growth. Fagus grandifolia had a higher morphological plasticity in response to light, which may offer a competitive advantage in occupying a broader range of light conditions throughout the canopy. Differences in responses to light and height for the taller tree species, L. tulipifera and F. grandifolia, may be attributed to differences in growth strategy or Al:As, which may alter morphological and functional responses to light availability. While height was important in F. grandifolia, height was no more robust in predicting LMA than light in any of the species, confirming the strong role of light availability in

  9. 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.

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

    Science.gov (United States)

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

    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 temperature treatments (11.2, 14.7, 18.0 and 21.4°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. PMID:18283501

  11. Patterns of radial and shoot growth of five tree species in a gamma-irradiated northern Wisconsin forest

    International Nuclear Information System (INIS)

    Zavitkovski, J.; Buech, R.R.; Rudolph, T.D.; Bauer, E.O.

    1977-01-01

    Patterns of radial and shoot growth of Abies balsamea, Acer rubrum, A. saccharum, Betula papyrifera, and Populus tremuloides were observed before (1970) and during (1972) gamma-irradiation of forest communities in the Enterprise Radiation Forest. Measurements were made during the growing season along the radiation gradient, and year days (YD) of 10, 25, 50, 75, and 90 percent of total growth were obtained by interpolation. The experimental area was divided into an ''affected'' and a ''no-effect'' zone. The boundary of the affected zone coincided with radiation exposures that effectively reduced the 1972 radial growth of a given species in comparison to the preirradiation growth. In 1970 and in the no-effect zone in 1972, shoot growth of the four broadleaved species started and terminated earlier than the radial growth. In A. balsamea the radial growth started earlier and terminated later than the shoot growth. In all five species, duration of radial growth was significantly longer than that of shoot growth. Radial growth of A. rubrum, A. saccharum, and B. papyrifera started significantly earlier in 1972 than in 1970, but no difference between years was found in the early-starting A. balsamea and P. tremuloides. In contrast, shoot growth of all five species started earlier in 1970 than in 1972. It is suggested that temperature regimes during the early developmental stages were probably responsible for the difference. In the affected zone in 1972, the radiation depressed radial growth and changed its normal pattern in all five species

  12. 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.

  13. 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.

  14. Pequi leaves incorporated into the soil reduce the initial growth of cultivated, invasive and native species.

    Science.gov (United States)

    Allem, Laísa N; Gomes, Anabele S; Borghetti, Fabian

    2014-12-01

    Studies have identified the phytotoxicity of many native species of the Cerrado; however, most of them were conducted either in inert substrates, or using exaggerate proportions of plant material. We investigated the phytotoxicity of pequi leaves added to substrate soil in quantities compatible with the litter produced by this species. Pequi leaves were triturated and added to red latosol in concentrations of 0.75%, 1.5% and 3%; the control was constituted of leafless soil. These mixtures were added to pots and irrigated daily to keep them moist. Germinated seeds of the cultivated sorghum and sesame, of the invasive brachiaria and of the native purple ipê, were disposed in the pots to grow for five to seven days at 30°C within a photoperiod of 12 h. Seedlings of all the species presented a reduction in their initial growth in a dose-dependent way. In general, the root growth was more affected by the treatments than the shoot growth; moreover, signs of necrosis were observed in the roots of the sorghum, sesame and brachiaria. The phytotoxic effects generated by relatively small quantities of leaves, in a reasonable range of species within a soil substrate, suggest potential allelopathy of pequi leaves under natural conditions.

  15. Pequi leaves incorporated into the soil reduce the initial growth of cultivated, invasive and native species

    Directory of Open Access Journals (Sweden)

    LAÍSA N. ALLEM

    2014-12-01

    Full Text Available Studies have identified the phytotoxicity of many native species of the Cerrado; however, most of them were conducted either in inert substrates, or using exaggerate proportions of plant material. We investigated the phytotoxicity of pequi leaves added to substrate soil in quantities compatible with the litter produced by this species. Pequi leaves were triturated and added to red latosol in concentrations of 0.75%, 1.5% and 3%; the control was constituted of leafless soil. These mixtures were added to pots and irrigated daily to keep them moist. Germinated seeds of the cultivated sorghum and sesame, of the invasive brachiaria and of the native purple ipê, were disposed in the pots to grow for five to seven days at 30°C within a photoperiod of 12 h. Seedlings of all the species presented a reduction in their initial growth in a dose-dependent way. In general, the root growth was more affected by the treatments than the shoot growth; moreover, signs of necrosis were observed in the roots of the sorghum, sesame and brachiaria. The phytotoxic effects generated by relatively small quantities of leaves, in a reasonable range of species within a soil substrate, suggest potential allelopathy of pequi leaves under natural conditions.

  16. Differences in growth trajectory and strategy of two sympatric congeneric species in an Indonesian floodplain forest.

    Science.gov (United States)

    Yamada, Toshihiro; Ngakan, Oka Putu; Suzuki, Eizi

    2005-01-01

    Whole-plant development trajectories and sapling leaf displays were compared for two sympatric congeneric species, Pterospermum diversifolium and P. javanicum, in a tropical floodplain forest in East Kalimantan, Indonesia. We assessed their growth strategies and developed hypotheses for their coexistence within the community. Pterospermum diversifolium retains a monoaxial growth habit that promotes quick stem elongation; thus, it is taller when branches are initiated than is P. javanicum. The species differed significantly in height growth and total crown expansion per unit increment of biomass: monoaxial P. diversifolium saplings devote more effort to stem elongation, whereas branched P. javanicum saplings devote more effort to branch expansion. Monoaxial P. diversifolium sustained more severe self-shading than P. javanicum. The sapling growth strategy of P. diversifolium appears to be dynamic, emphasizing the opportunistic use of light following a disturbance, whereas that of P. javanicum appears to be static, optimizing leaf display for current light conditions. The advantages of these strategies depend on context, and the two species may coexist within a community by adopting different regeneration niches based on differing understory light conditions: P. diversifolium is favored over P. javanicum at high light levels, but the opposite is true at low light levels.

  17. 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

  18. 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.

  19. 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.

  20. 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)

  1. Growth promotion and inhibition of the Amazonian wild rice species Oryza grandiglumis to survive flooding.

    Science.gov (United States)

    Okishio, Takuma; Sasayama, Daisuke; Hirano, Tatsuya; Akimoto, Masahiro; Itoh, Kazuyuki; Azuma, Tetsushi

    2014-09-01

    In Asian cultivated rice (Oryza sativa), distinct mechanisms to survive flooding are activated in two groups of varieties. Submergence-tolerant rice varieties possessing the SUBMERGENCE1A (SUB1A) gene display reduced growth during flash floods at the seedling stage and resume growth after the flood recedes, whereas deepwater rice varieties possessing the SNORKEL1 (SK1) and SNORKEL2 (SK2) genes display enhanced growth based on internodal elongation during prolonged submergence at the mature stage. In this study, we investigated the occurrence of these growth responses to submergence in the wild rice species Oryza grandiglumis, which is native to the Amazon floodplains. When subjected to gradual submergence, adult plants of O. grandiglumis accessions showed enhanced internodal elongation with rising water level and their growth response closely resembled that of deepwater varieties of O. sativa with high floating capacity. On the other hand, when subjected to complete submergence, seedlings of O. grandiglumis accessions displayed reduced shoot growth and resumed normal growth after desubmergence, similar to the response of submergence-tolerant varieties of O. sativa. Neither SUB1A nor the SK genes were detected in the O. grandiglumis accessions. These results indicate that the O. grandiglumis accessions are capable of adapting successfully to flooding by activating two contrasting mechanisms as the situation demands and that each mechanism of adaptation to flooding is not mediated by SUB1A or the SK genes.

  2. Site- and Species-Specific Influences on Sub-Alpine Conifer Growth in Mt. Rainier National Park, USA

    Directory of Open Access Journals (Sweden)

    Myesa Legendre-Fixx

    2017-12-01

    Full Text Available Identifying the factors that influence the climate sensitivity of treeline species is critical to understanding carbon sequestration, forest dynamics, and conservation in high elevation forest/meadow ecotones. Using tree cores from four sub-alpine conifer species collected from three sides of Mt. Rainier, WA, USA, we investigated the influences of species identity and sites with different local climates on radial growth–climate relationships. We created chronologies for each species at each site, determined influential plant-relevant annual and seasonal climatic variables influencing growth, and investigated how the strength of climate sensitivity varied across species and location. Overall, similar climate variables constrained growth on all three sides of the mountain for each of the four study species. Summer warmth positively influenced radial growth, whereas snow, spring warmth, previous summer warmth, and spring humidity negatively influenced growth. We discovered only a few subtle differences in the climate sensitivity of co-occurring species at the same site and between the same species at different sites in pairwise comparisons. A model including species by climate interactions provided the best balance between parsimony and fit, but did not lead to substantially greater predictive power relative to a model without site or species interactions. Our results imply that at treeline in moist temperate regions like Mt. Rainier, the same climatic variables drive annual variation in growth across species and locations, despite species differences in physiology and site differences in mean climates.

  3. 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).

  4. 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.

  5. 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.

  6. 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.

  7. Winery wastewater inhibits seed germination and vegetative growth of common crop species.

    Science.gov (United States)

    Mosse, Kim P M; Patti, Antonio F; Christen, Evan W; Cavagnaro, Timothy R

    2010-08-15

    The ability to reuse winery wastewater would be of significant benefit to the wine industry, as it could potentially be a cost-effective method of wastewater management, whilst at the same time providing a valuable water resource. This study investigated the effects of different dilutions of a semi-synthetic winery wastewater on the growth and germination of four common crop species in a glasshouse study; barley (Hordeum vulgare), millet (Pennisetum glaucum), lucerne (Medicago sativa) and phalaris (Phalaris aquatica). The wastewater caused a significant delay in the germination of lucerne, millet and phalaris, although overall germination percentage of all species was not affected. Vegetative growth was significantly reduced in all species, with millet being the most severely affected. The germination index of barley correlated very highly (r(2)=0.99) with barley biomass, indicating that barley seed germination bioassays are highly relevant to plant growth, and therefore may be of use as a bioassay for winery wastewater toxicity. Copyright 2010 Elsevier B.V. All rights reserved.

  8. 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 enzymes, superoxide dismutase (SOD) and 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.

  9. 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.

  10. 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.

  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. 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)

  13. Phenology and growth in four annual species grown in ambient and elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Reekie, E.G. (Acadia Univ., Wolfville, NS (Canada)); Bazzaz, F.A. (Harvard Univ., Cambridge, MA (USA))

    1991-01-01

    The objectives of this study were to test the hypothesis that changes in phenology with CO{sub 2} are a function of the effect of CO{sub 2} upon growth and to determine if CO{sub 2}-induced changes in phenology can influence competitive outcome. The effect of 350, 525, and 700{mu}l/l CO{sub 2} on Guara brachycarpa, Gailardia pulchella, Oenothera laciniata, and Lupinus texenis was examined. Plants were grown as individuals in 150-, 500-, or 1000-ml pots and in competition in 1000-ml pots. Growth and development were monitored at twice-weekly intervals by recording the number of leaves and noting the presence or absence of stem elongation, branching, flower buds, and open flowers. Elevated CO{sub 2} affected both growth and phenology, but the direction and magnitude of effects varied with species and soil volume. Elevated CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} on growth were generally different from those treatments in which CO{sub 2} affected phenology. Rather than affecting phenology by changing plant size, CO{sub 2} appeared to affect phenology by modifying the size at which plants switched from one stage to the next. The level of CO{sub 2} changed competitive outcome; the importance of Lupinus increased whereas that of Oenothera decreased with increased CO{sub 2}. These changes were more closely related to the effect of CO{sub 2} on growth than its effect on phenology. 19 refs., 2 figs., 4 tabs.

  14. No evidence for consistent long-term growth stimulation of 13 tropical tree species: results from tree-ring analysis.

    Science.gov (United States)

    Groenendijk, Peter; van der Sleen, Peter; Vlam, Mart; Bunyavejchewin, Sarayudh; Bongers, Frans; Zuidema, Pieter A

    2015-10-01

    The important role of tropical forests in the global carbon cycle makes it imperative to assess changes in their carbon dynamics for accurate projections of future climate-vegetation feedbacks. Forest monitoring studies conducted over the past decades have found evidence for both increasing and decreasing growth rates of tropical forest trees. The limited duration of these studies restrained analyses to decadal scales, and it is still unclear whether growth changes occurred over longer time scales, as would be expected if CO2 -fertilization stimulated tree growth. Furthermore, studies have so far dealt with changes in biomass gain at forest-stand level, but insights into species-specific growth changes - that ultimately determine community-level responses - are lacking. Here, we analyse species-specific growth changes on a centennial scale, using growth data from tree-ring analysis for 13 tree species (~1300 trees), from three sites distributed across the tropics. We used an established (regional curve standardization) and a new (size-class isolation) growth-trend detection method and explicitly assessed the influence of biases on the trend detection. In addition, we assessed whether aggregated trends were present within and across study sites. We found evidence for decreasing growth rates over time for 8-10 species, whereas increases were noted for two species and one showed no trend. Additionally, we found evidence for weak aggregated growth decreases at the site in Thailand and when analysing all sites simultaneously. The observed growth reductions suggest deteriorating growth conditions, perhaps due to warming. However, other causes cannot be excluded, such as recovery from large-scale disturbances or changing forest dynamics. Our findings contrast growth patterns that would be expected if elevated CO2 would stimulate tree growth. These results suggest that commonly assumed growth increases of tropical forests may not occur, which could lead to erroneous

  15. [A Cellular Automata Model for a Community Comprising Two Plant Species of Different Growth Forms].

    Science.gov (United States)

    Frolov, P V; Zubkova, E V; Komarov, A S

    2015-01-01

    A cellular automata computer model for the interactions between two plant species of different growth forms--the lime hairgrass Deschampsia caespitosa (L.) P. Beauv., a sod cereal, and the moneywort Lysimachia nummularia L., a ground creeping perennial herb--is considered. Computer experiments on the self-maintenance of the populations of each species against the background of a gradual increase in the share of randomly eliminated individuals, coexistence of the populations of two species, and the effect of the phytogenous field have been conducted. As has been shown, all the studied factors determine the number of individuals and self-sustainability of the simulated populations by the degree of their impact. The limits of action have been determined for individual factors; within these limits, the specific features in plant reproduction and dispersal provide sustainable coexistence of the simulated populations. It has been demonstrated that the constructed model allows for studying the long-term developmental dynamics of the plants belonging to the selected growth forms.

  16. 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.

  17. Planktonic growth and biofilm formation profiles in Candida haemulonii species complex.

    Science.gov (United States)

    Ramos, Lívia S; Oliveira, Simone S C; Souto, Xênia M; Branquinha, Marta H; Santos, André L S

    2017-10-01

    Candida haemulonii species complex have emerged as multidrug-resistant yeasts able to cause fungemia worldwide. However, very little is known regarding their physiology and virulence factors. In this context, planktonic growth and biofilm formation of Brazilian clinical isolates of Candida haemulonii (n = 5), Candida duobushaemulonii (n = 4), and Candida haemulonii var. vulnera (n = 3) were reported. Overall, the fungal planktonic growth curves in Sabouraud dextrose broth reached the exponential phase in 48 h at 37°C. All the clinical isolates formed biofilm on polystyrene in a time-dependent event, as judged by the parameters evaluated: biomass (crystal violet staining), metabolic activity (XTT reduction), and extracellular matrix (safranin incorporation). No statistically significant differences were observed when the average measurements among the three Candida species were compared regarding both planktonic and biofilm lifestyles; however, typical isolate-specific differences were clearly noticed in fungal growth kinetics. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Effect of Aqueous Extracts from Weed Species on Germination and Initial Growth in Raphanus sativus L.

    Directory of Open Access Journals (Sweden)

    Anisoara STRATU

    2015-12-01

    Full Text Available The current paper presents the results of a study on the effects of aqueous extracts from five weed species (Amaranthus retroflexus, Cirsium arvense, Convolvulus arvensis, Echinochloa crus-galii, Setaria verticillata on germination and initial growth in Raphanus sativus L. The following indicators have been analyzed: indices of germination (the germination percentage; the speed of germination; the speed of accumulated germination and the coefficient of germination rate, the length of the root and hypocotyls, the pH of aqueous extracts, the UV-Vis absorption spectra of aqueous extracts. The results of the investigations showed the following aspects: the aqueous extracts reduced the values of calculated germination indices and root growth in the first ontogenetic stages of the test species; the pH of the extracts was slightly acid to neutral. Qualitative spectrophotometric analysis indicated the possible presence of phenolic and organic compounds in the extracts. C. arvense, S. verticillata and E. crus-galii presented the most pronounced effect on germination and growth processes.

  19. Plant growth-promoting Burkholderia species isolated from annual ryegrass in Portuguese soils.

    Science.gov (United States)

    Castanheira, N; Dourado, A C; Kruz, S; Alves, P I L; Delgado-Rodríguez, A I; Pais, I; Semedo, J; Scotti-Campos, P; Sánchez, C; Borges, N; Carvalho, G; Barreto Crespo, M T; Fareleira, P

    2016-03-01

    To search for culturable Burkholderia species associated with annual ryegrass in soils from natural pastures in Portugal, with plant growth-promoting effects. Annual ryegrass seedlings were used to trap Burkholderia from two different soils in laboratory conditions. A combined approach using genomic fingerprinting and sequencing of 16S rRNA and recA genes resulted in the identification of Burkholderia strains belonging to the species Burkholderia graminis, Burkholderia fungorum and the Burkholderia cepacia complex. Most strains were able to solubilize mineral phosphate and to synthesize indole acetic acid; some of them could produce siderophores and antagonize the phytopathogenic oomycete, Phytophthora cinnamomi. A strain (G2Bd5) of B. graminis was selected for gnotobiotic plant inoculation experiments. The main effects were the stimulation of root growth and enhancement of leaf lipid synthesis and turnover. Fluorescence in situ hybridization and confocal laser microscopy evidenced that strain G2Bd5 is a rhizospheric and endophytic colonizer of annual ryegrass. This work revealed that annual ryegrass can naturally associate with members of the genus Burkholderia. A novel plant growth promoting strain of B. graminis was obtained. The novel strain belongs to the plant-associated Burkholderia cluster and is a promising candidate for exploitation as plant inoculant in field conditions. © 2015 The Society for Applied Microbiology.

  20. Growth and development of chicks of two species of partridge: the grey partridge (Perdix perdix) and the chukar (Alectoris chukar).

    Science.gov (United States)

    Pis, Tomasz

    2012-01-01

    1. In two partridge species, the grey partridge (Perdix perdix) and chukar (Alectoris chukar), from hatching up to 120 d, the growth rate and development of body mass, wing, tarsus, and bill length were measured and fitted by Gompertz equations. 2. As a typical precocial species, partridges hatched with relatively well developed legs and bills, and wing growth followed a gradual development of thermoregulation. 3. Gompertz growth constants for body mass growth were 0·039 and 0·038 for grey partridges and chukars, respectively. 4. The allometric relationship between tarsus length and body mass followed a geometric similarity (1/3 power) in both grey partridges and chukars.

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

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    Full Text Available 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.

  3. Effects of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species.

    Science.gov (United States)

    Caglar, S; Akgun, A

    2006-07-01

    The experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species used as rootstocks. The stratified Pistacia seeds were inoculated with VAM fungi. The highest rate of inoculated roots was 96.7% in P. khinjuck seedlings with G. clarum and G. etunicatum, 83.3% in P. vera seedlings with G. caledonium and 73.3% in P. terebinthus seedlings with G. caledonium. Mycorrhizal inoculations improved seedling height only in P. terebinthus. Certain mycorrhizal inoculations increased the leaf N, but not P and K contents. Seedlings inoculated with G. caledonium had higher reducing sugar contents. It was concluded that pre-inoculated Pistacia seedlings could have a better growth in the harsh field conditions.

  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. 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.

  6. Some aspects of the Seed Germination and Seedling Growth of two Savanna tree Species

    Directory of Open Access Journals (Sweden)

    D.A. Agboola

    2014-10-01

    Full Text Available Studies were made on some aspects of the seed germination and seedling growth of two multipurpose trees. These include the effect of pre sowing treatments, seed sizes and gibberellic acid on the germination of seeds and seedling growth. The tree species include Prosopis africana (Guil & Perr Taub and Dialium guineense (wild. Two seed sizes designated small- size (Ss and Big-size (Bs were identified in the seed. The effect of gibberellic acid (GA3 had a greater significance effect (P < 0.05 on seed germination of both D. guineense and P. africana seeds. The big size seeds had a significant effect (P < 0.05 on the seed germination when compared to the small size seeds. The hydration/dehydration, pre sowing treatments on the seeds did not have any significant effects on germination.

  7. GROWTH AND NUTRITIONAL ANALYSIS OF TREE SPECIES IN CONTAMINATED SUBSTRATE BY LEACHABLE HERBICIDES

    Directory of Open Access Journals (Sweden)

    Rebecca de Araújo Fiore

    Full Text Available ABSTRACT Ecosystems contamination by residues of pesticides requires special attention to the herbicides subject to leaching. The objective was to select tree species to rhizodegradation contaminated by residues of 2,4-D and atrazine and to recompose riparian areas to agricultural fields, then reducing the risk of contamination of water courses. A total of 36 treatments consisted of the combinations of forest species were evaluated [Inga marginata (Inga, Schizolobium parahyba (guapuruvu, Handroanthus serratifolius (ipê amarelo, Jacaranda puberula (carobinha, Cedrela fissilis (cedro, Calophyllum brasiliensis (landin, Psidium mirsinoides (goiabinha, Tibouchina glandulosa (quaresmeira, Caesalpinia férrea (pau-ferro, Caesalpinia pluviosa (sibipiruna, Terminalia argêntea (capitão and Schinopsis brasiliensis (braúna] and three solutions simulating leachate compound (atrazine, 2,4-D and water - control, with four replicates each. The characteristics measured were plant height, stem diameter, number of leaves, leaf area and dry biomass, and foliar nutrition. Forest species survived the herbicide application, and most showed an increase in macronutrients even under an herbicide application, and the Inga had the highest tolerance regarding growth analysis. It is recommended to use species that are more tolerant to Atrazine and 2,4-D in field experiments to confirm previous results of this simulation.

  8. 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.

  9. 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.

  10. 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

  11. Nest predation risk and growth strategies of passerine species: grow fast or develop traits to escape risk?

    Science.gov (United States)

    Cheng, Yi-Ru; Martin, Thomas E.

    2012-01-01

    Different body components are thought to trade off in their growth and development rates, but the causes for relative prioritization of any trait remains a critical question. Offspring of species at higher risk of predation might prioritize development of locomotor traits that facilitate escaping risky environments over growth of mass. We tested this possibility in 12 altricial passerine species that differed in their risk of nest predation. We found that rates of growth and development of mass, wings, and endothermy increased with nest predation risk across species. In particular, species with higher nest predation risk exhibited relatively faster growth of wings than of mass, fledged with relatively larger wing sizes and smaller mass, and developed endothermy earlier at relatively smaller mass. This differential development can facilitate both escape from predators and survival outside of the nest environment. Tarsus growth was not differentially prioritized with respect to nest predation risk, and instead all species achieved adult tarsus size by age of fledging. We also tested whether different foraging modes (aerial, arboreal, and ground foragers) might explain the variation of differential growth of locomotor modules, but we found that little residual variation was explained. Our results suggest that differences in nest predation risk among species are associated with relative prioritization of body components to facilitate escape from the risky nest environment.

  12. 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.

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Mathias Klein

    2016-12-01

    Full Text Available 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 gDW/gglycerol 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. Keywords: Yeast, Saccharomyces cerevisiae, Glycerol, Transport, Glycerol facilitator, Fps1, Stl1

  15. 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...

  16. Species and structural diversity affect growth of oak, but not pine, in uneven-aged mature forests

    NARCIS (Netherlands)

    Vanhellemont, Margot; Bijlsma, Rienk Jan; Keersmaeker, De Luc; Vandekerkhove, Kris; Verheyen, Kris

    2018-01-01

    The effects of mixing tree species on tree growth and stand production have been abundantly studied, mostly looking at tree species diversity effects while controlling for stand density and structure. Regarding the shift towards managing forests as complex adaptive systems, we also need insight into

  17. Quantifying climate-growth relationships at the stand level in a mature mixed-species conifer forest.

    Science.gov (United States)

    Teets, Aaron; Fraver, Shawn; Weiskittel, Aaron R; Hollinger, David Y

    2018-03-11

    A range of environmental factors regulate tree growth; however, climate is generally thought to most strongly influence year-to-year variability in growth. Numerous dendrochronological (tree-ring) studies have identified climate factors that influence year-to-year variability in growth for given tree species and location. However, traditional dendrochronology methods have limitations that prevent them from adequately assessing stand-level (as opposed to species-level) growth. We argue that stand-level growth analyses provide a more meaningful assessment of forest response to climate fluctuations, as well as the management options that may be employed to sustain forest productivity. Working in a mature, mixed-species stand at the Howland Research Forest of central Maine, USA, we used two alternatives to traditional dendrochronological analyses by (1) selecting trees for coring using a stratified (by size and species), random sampling method that ensures a representative sample of the stand, and (2) converting ring widths to biomass increments, which once summed, produced a representation of stand-level growth, while maintaining species identities or canopy position if needed. We then tested the relative influence of seasonal climate variables on year-to-year variability in the biomass increment using generalized least squares regression, while accounting for temporal autocorrelation. Our results indicate that stand-level growth responded most strongly to previous summer and current spring climate variables, resulting from a combination of individualistic climate responses occurring at the species- and canopy-position level. Our climate models were better fit to stand-level biomass increment than to species-level or canopy-position summaries. The relative growth responses (i.e., percent change) predicted from the most influential climate variables indicate stand-level growth varies less from to year-to-year than species-level or canopy-position growth responses. By

  18. Fern Stomatal Responses to ABA and CO2 Depend 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.

  19. 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)

  20. Growth and elemental content of two tree species growing on abandoned coal fly ash basins

    International Nuclear Information System (INIS)

    Carlson, C.L.; Adriano, D.C.

    1991-01-01

    Differences in aboveground tissue concentrations of trace elements were assessed for sweetgum (Liquidambar styraciflua L.) and sycamore (Plantanus occidentalis L.) growing on two abandoned coal fly ash basins and a control soil. The wet basin (pH = 5.58) had originally received precipitator ash in an ash-water slurry, while the dry basin (pH = 8.26) had received both precipitator and bottom ash in dry form. In general, trees from the wet basin exhibited elevated trace element concentrations in comparison to the controls, while the dry basin trees exhibited reduced concentrations. On eof the most striking differenced in elemental concentrations among the ash basin and control trees was observed for Mn, with the control trees exhibiting concentrations orders of magnitude greater than the ash basin trees. Differences in foliar trace element concentrations among the sites can generally be explained by differences in substrate trace element concentrations and/or substrate pH. While trees from the wet ash basin generally had the highest trace element concentrations, these trees also attained the greatest height and diameter growth, suggesting that the elevated trace element concentrations in the wet basin substrate are not limiting the establishment of these two species. The greater height and diameter growth of the wet basin trees is presumably a result of the greater water-holding capacity of the substrate on this site. Differences in growth and tissue concentrations between sweetgum and sycamore highlight the importance of using more than one species when assessing metal toxicity or deficiency on a given substrate

  1. 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.

  2. 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.

    2016-01-01

    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 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. PMID:27869215

  3. 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

    2014-01-01

    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 (Q208A) 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 (Q208A) 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. PMID:24350979

  4. 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.

  5. The Impact of Moss Species and Biomass on the Growth of Pinus sylvestris Tree Seedlings at Different Precipitation Frequencies

    Directory of Open Access Journals (Sweden)

    Babs M. Stuiver

    2014-08-01

    Full Text Available Boreal forests are characterized by an extensive moss layer, which may have both competitive and facilitative effects on forest regeneration. We conducted a greenhouse experiment to investigate how variation in moss species and biomass, in combination with precipitation frequency, affect Pinus sylvestris seedling growth. We found that moss species differed in their effects on seedling growth, and moss biomass had negative effects on seedlings, primarily when it reached maximal levels. When moss biomass was maximal, seedling biomass decreased, whereas height and above- relative to below-ground mass increased, due to competition for light. The effect that moss biomass had on seedling performance differed among the moss species. Hylocomium splendens and Polytrichum commune reduced seedling growth the most, likely because of their taller growth form. Seedlings were not adversely affected by Sphagnum girgensohnii and Pleurozium schreberi, possibly because they were not tall enough to compete for light and improved soil resource availability. Reduced precipitation frequency decreased the growth of all moss species, except P. commune, while it impaired the growth of seedlings only when they were grown with P. commune. Our findings suggest that changes in moss species and biomass, which can be altered by disturbance or climate change, can influence forest regeneration.

  6. 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

    -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...... 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...... 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 wine fermentations....

  7. Determining the annual periodicity of growth rings in seven tree species of a tropical moist forest in Santa Cruz, Bolivia

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, L.; Villalba, R.; Pena-Claros, M.

    2012-07-01

    To determine the annual periodicity of growth rings in seven tree species from a tropical moist forest in Santa Cruz, Bolivia, a fire scar was used as a marker point to verify the annual nature of tree rings. The number of tree rings formed between the 1995 fire scar and the collection of the cross sections in 2002 was visually identified. The seven species showed annual growth rings. In most cases, boundaries between rings were marked by the presence of marginal parenchyma and wall-thick ed fibers formed at the end of the growing season. Growth lenses and false rings were recorded in some species. Tree rings can be carefully used in Santa Cruz forests to determine rates of growth. This information is crucial for defining forest management practices in tropical regions. (Author) 21 refs.

  8. Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

    Science.gov (United States)

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

    Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines.

  9. 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.

  10. Identifying conservation and restoration priorities for saproxylic and old-growth forest species: a case study in Switzerland.

    Science.gov (United States)

    Lachat, Thibault; Bütler, Rita

    2009-07-01

    Saproxylic (dead-wood-associated) and old-growth species are among the most threatened species in European forest ecosystems, as they are susceptible to intensive forest management. Identifying areas with particular relevant features of biodiversity is of prime concern when developing species conservation and habitat restoration strategies and in optimizing resource investments. We present an approach to identify regional conservation and restoration priorities even if knowledge on species distribution is weak, such as for saproxylic and old-growth species in Switzerland. Habitat suitability maps were modeled for an expert-based selection of 55 focal species, using an ecological niche factor analyses (ENFA). All the maps were then overlaid, in order to identify potential species' hotspots for different species groups of the 55 focal species (e.g., birds, fungi, red-listed species). We found that hotspots for various species groups did not correspond. Our results indicate that an approach based on "richness hotspots" may fail to conserve specific species groups. We hence recommend defining a biodiversity conservation strategy prior to implementing conservation/restoration efforts in specific regions. The conservation priority setting of the five biogeographical regions in Switzerland, however, did not differ when different hotspot definitions were applied. This observation emphasizes that the chosen method is robust. Since the ENFA needs only presence data, this species prediction method seems to be useful for any situation where the species distribution is poorly known and/or absence data are lacking. In order to identify priorities for either conservation or restoration efforts, we recommend a method based on presence data only, because absence data may reflect factors unrelated to species presence.

  11. Redox state, reactive oxygen species and adaptive growth in colonial hydroids.

    Science.gov (United States)

    Blackstone, N W

    2001-06-01

    Colonial metazoans often encrust surfaces over which the food supply varies in time or space. In such an environment, adaptive colony development entails adjusting the timing and spacing of feeding structures and gastrovascular connections to correspond to this variable food supply. To investigate the possibility of such adaptive growth, within-colony differential feeding experiments were carried out using the hydroid Podocoryna carnea. Indeed, such colonies strongly exhibited adaptive growth, developing dense arrays of polyps (feeding structures) and gastrovascular connections in areas that were fed relative to areas that were starved, and this effect became more consistent over time. To investigate mechanisms of signaling between the food supply and colony development, measurements were taken of metabolic parameters that have been implicated in signal transduction in other systems, particularly redox state and levels of reactive oxygen species. Utilizing fluorescence microscopy of P. carnea cells in vivo, simultaneous measurements of redox state [using NAD(P)H] and hydrogen peroxide (using 2',7'-dichlorofluorescin diacetate) were taken. Both measures focused on polyp epitheliomuscular cells, since these exhibit the greatest metabolic activity. Colonies 3-5h after feeding were relatively oxidized, with low levels of peroxide, while colonies 24h after feeding were relatively reduced, with high levels of peroxide. The functional role of polyps in feeding and generating gastrovascular flow probably produced this dichotomy. Polyps 3-5h after feeding contract maximally, and this metabolic demand probably shifts the redox state in the direction of oxidation and diminishes levels of reactive oxygen species. In contrast, 24h after feeding, polyps are quiescent, and this lack of metabolic demand probably shifts the redox state in the direction of reduction and increases levels of reactive oxygen species. Within-colony differential feeding experiments were carried out on

  12. Diel time-courses of leaf growth in monocot and dicot species: endogenous rhythms and temperature effects.

    Science.gov (United States)

    Poiré, Richard; Wiese-Klinkenberg, Anika; Parent, Boris; Mielewczik, Michael; Schurr, Ulrich; Tardieu, François; Walter, Achim

    2010-06-01

    Diel (24 h) leaf growth patterns were differently affected by temperature variations and the circadian clock in several plant species. In the monocotyledon Zea mays, leaf elongation rate closely followed changes in temperature. In the dicotyledons Nicotiana tabacum, Ricinus communis, and Flaveria bidentis, the effect of temperature regimes was less obvious and leaf growth exhibited a clear circadian oscillation. These differences were related neither to primary metabolism nor to altered carbohydrate availability for growth. The effect of endogenous rhythms on leaf growth was analysed under continuous light in Arabidopsis thaliana, Ricinus communis, Zea mays, and Oryza sativa. No rhythmic growth was observed under continuous light in the two monocotyledons, while growth rhythmicity persisted in the two dicotyledons. Based on model simulations it is concluded that diel leaf growth patterns in mono- and dicotyledons result from the additive effects of both circadian-clock-controlled processes and responses to environmental changes such as temperature and evaporative demand. Apparently very distinct diel leaf growth behaviour of monocotyledons and dicotyledons can thus be explained by the different degrees to which diel temperature variations affect leaf growth in the two groups of species which, in turn, depends on the extent of the leaf growth control by internal clocks.

  13. 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

  14. The Ocean's Carbon Factory: Ocean Composition. The Growth Patterns of Phytoplankton Species

    Science.gov (United States)

    Gregg, Watson

    2000-01-01

    According to biological data recorded by the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) satellite, the ocean contains nearly half of all the Earth's photosynthesis activity. Through photosynthesis, plant life forms use carbon from the atmosphere, and in return, plants produce the oxygen that life requires. In effect, ocean chlorophyll works like a factory, taking carbon and "manufacturing" the air we breathe. Most ocean-bound photosynthesis is performed by single-celled plants called phytoplankton. "These things are so small," according to Michael Behrenfeld, a researcher at NASA Goddard Space Flight Center, "that if you take hundreds of them and stack them end-to-end, the length of that stack is only the thickness of a penny". The humble phytoplankton species plays a vital role in balancing the amounts of oxygen and carbon dioxide in the atmosphere. Therefore, understanding exactly how phytoplankton growth works is important.

  15. Disentangling the effects of climate, species, and management on growth and mortality of southeast Asian mangroves

    Science.gov (United States)

    Baker, Patrick; Bunyavejchewin, Sarayudh; Robinson, Andrew

    2013-04-01

    Mangrove forests are one of the most biologically important ecosystems of the littoral tropics. They provide a wide range of ecosystem services including tsunami protection, food production, and waste processing. They are also rapidly disappearing due to increasing rates of clearance for development and aquaculture. It remains unclear how mangroves will respond to changing climatic conditions. Here we discuss the results of a long-term study that explored the interacting effects of climate, species, and management practices on annual variability of growth and mortality of mangroves in peninsular Thailand. The 15-year study period included the extreme 1997-98 ENSO event that led to widespread drought-induced mortality and forest fires across the region, but which appeared to have little impact on the mangroves. Our results provide an important, and much-needed, framework for conservation and forest management planning in these mangrove forests given future concerns and uncertainty about climate change in the tropics.

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

    Science.gov (United States)

    Kipfer, Tabea; Wohlgemuth, Thomas; van der Heijden, Marcel G A; Ghazoul, Jaboury; Egli, Simon

    2012-01-01

    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.

  18. Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests

    Science.gov (United States)

    Oberle, B.; Grace, J.B.; Chase, J.M.

    2009-01-01

    Aim: Species richness has been observed to increase with productivity at large spatial scales, though the strength of this relationship varies among functional groups. In forests, canopy trees shade understorey plants, and for this reason we hypothesize that species richness of canopy trees will depend on macroclimate, while species richness of shorter growth forms will additionally be affected by shading from the canopy. In this study we test for differences in species richness-productivity relationships (SRPRs) among growth forms (canopy trees, shrubs, herbaceous species) in small forest plots. Location: We analysed 231 plots ranging from 34.0?? to 48.3?? N latitude and from 75.0?? to 124.2?? W longitude in the United States. Methods: We analysed data collected by the USDA Forest Inventory and Analysis program for plant species richness partitioned into different growth forms, in small plots. We used actual evapotranspiration as a macroclimatic estimate of regional productivity and calculated the area of light-blocking tissue in the immediate area surrounding plots for an estimate of the intensity of local shading. We estimated and compared SRPRs for different partitions of the species richness dataset using generalized linear models and we incorporated the possible indirect effects of shading using a structural equation model. Results: Canopy tree species richness increased strongly with regional productivity, while local shading primarily explained the variation in herbaceous plant richness. Shrub species richness was related to both regional productivity and local shading. Main conclusions: The relationship between total forest plant species richness and productivity at large scales belies strong effects of local interactions. Counter to the pattern for overall richness, we found that understorey herbaceous plant species richness does not respond to regional productivity gradients, and instead is strongly influenced by canopy density, while shrub species

  19. Sex roles, parental care and offspring growth in two contrasting coucal species.

    Science.gov (United States)

    Goymann, Wolfgang; Safari, Ignas; Muck, Christina; Schwabl, Ingrid

    2016-10-01

    The decision to provide parental care is often associated with trade-offs, because resources allocated to parental care typically cannot be invested in self-maintenance or mating. In most animals, females provide more parental care than males, but the reason for this pattern is still debated in evolutionary ecology. To better understand sex differences in parental care and its consequences, we need to study closely related species where the sexes differ in offspring care. We investigated parental care in relation to offspring growth in two closely related coucal species that fundamentally differ in sex roles and parental care, but live in the same food-rich habitat with a benign climate and have a similar breeding phenology. Incubation patterns differed and uniparental male black coucals fed their offspring two times more often than female and male white-browed coucals combined. Also, white-browed coucals had more 'off-times' than male black coucals, during which they perched and preened. However, these differences in parental care were not reflected in offspring growth, probably because white-browed coucals fed their nestlings a larger proportion of frogs than insects. A food-rich habitat with a benign climate may be a necessary, but-perhaps unsurprisingly-is not a sufficient factor for the evolution of uniparental care. In combination with previous results (Goymann et al . 2015 J. Evol. Biol . 28 , 1335-1353 (doi:10.1111/jeb.12657)), these data suggest that white-browed coucals may cooperate in parental care, because they lack opportunities to become polygamous rather than because both parents were needed to successfully raise all offspring. Our case study supports recent theory suggesting that permissive environmental conditions in combination with a particular life history may induce sexual selection in females. A positive feedback loop among sexual selection, body size and adult sex-ratio may then stabilize reversed sex roles in competition and parental care.

  20. Uptake of different species of iodine by water spinach and its effect to growth.

    Science.gov (United States)

    Weng, Huan-Xin; Yan, Ai-Lan; Hong, Chun-Lai; Xie, Lin-Li; Qin, Ya-Chao; Cheng, Charles Q

    2008-08-01

    A hydroponic experiment has been carried out to study the influence of iodine species [iodide (I(-)), iodate (IO(-)(3)), and iodoacetic acid (CH(2)ICOO(-))] and concentrations on iodine uptake by water spinach. Results show that low levels of iodine in the nutrient solution can effectively stimulate the growth of biomass of water spinach. When iodine levels in the nutrient solution are from 0 to 1.0 mg/l, increases in iodine levels can linearly augment iodine uptake rate by the leafy vegetables from all three species of iodine, and the uptake effects are in the following order: CH(2)ICOO(-) >I(-)>IO(-)(3). In addition, linear correlation was observed between iodine content in the roots and shoots of water spinach, and their proportion is 1:1. By uptake of I(-), vitamin C (Vit C) content in water spinach increased, whereas uptake of IO(-)(3) and CH(2)ICOO(-) decreased water spinach Vit C content. Furthermore, through uptake of I(-) and IO(-)(3). The nitrate content in water spinach was increased by different degrees.

  1. 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

  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. 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

  4. 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.

  5. Growth and {delta}{sup 13}C responses to increasing atmospheric carbon dioxide concentrations for several crop species

    Energy Technology Data Exchange (ETDEWEB)

    Hanba, Y.T.; Wada, E. [Center for Ecological Research, Kyoto University, Kyoto (Japan); Osaki, M.; Nakamura, T. [Faculty of Agriculture, Hokkaido University, Hokkaido (Japan)

    1996-04-01

    The responses of plant growth and carbon isotope discrimination ({Delta}) to elevated atmospheric CO{sub 2} concentrations for several crop species (lettuce: Lactuca sativa L.; corn: Zea Mays L. var. P3540, wheat: Triticum aestivum L. var Haruyutaka; and soybean: Glycine Max (L). Merr. var. Kitamusume) were investigated. Shoot relative growth rate was used to indicate plant growth, and {delta}{sup 13}C value of leaf materials in corn (C4 species) was used to calculate {Delta} for C3 species. Plant growth was stimulated by enriched CO{sub 2}, while {Delta} remained almost constant as CO{sub 2} concentration changed. {Delta} showed interspecific difference, and the plant species of larger {Delta} had larger relative growth rates. Relative growth rates of the plants of larger {Delta} were stimulated by CO{sub 2} enrichment more than those of the plants of smaller {Delta}. We propose that plant {Delta} could be a possible parameter to assess the interspecific difference of plant response to the increasing atmospheric CO{sub 2} concentrations. 3 figs., 2 tabs., 25 refs.

  6. Studies on cambial activity: advances and challenges in the knowledge of growth dynamics of Brazilian woody species

    Directory of Open Access Journals (Sweden)

    CÁTIA H. CALLADO

    2014-03-01

    Full Text Available The lack of specific research on the sequence of events that determine plant growth from meristem until wood formation represents a gap in the knowledge of growth dynamics in woody species. In this work, we surveyed published studies concerning cambial activity of Brazilian native species aiming at allowing the comparison of applied methods and obtained results. The annual cambial seasonality was observed in all the investigated species. Nevertheless, we found high heterogeneity in the used methodologies. As a result from this analysis, our opinion points to the need for standardizing sampling protocols and for discussing the suitability of experimental designs. This will help to define with greater precision the factors that determine the radial growth in the different tropical ecosystems.

  7. Growth and phenology of three dwarf shrub species in a six-year soil warming experiment at the alpine treeline.

    Science.gov (United States)

    Anadon-Rosell, Alba; Rixen, Christian; Cherubini, Paolo; Wipf, Sonja; Hagedorn, Frank; Dawes, Melissa A

    2014-01-01

    Global warming can have substantial impacts on the phenological and growth patterns of alpine and Arctic species, resulting in shifts in plant community composition and ecosystem dynamics. We evaluated the effects of a six-year experimental soil warming treatment (+4°C, 2007-2012) on the phenology and growth of three co-dominant dwarf shrub species growing in the understory of Larix decidua and Pinus uncinata at treeline in the Swiss Alps. We monitored vegetative and reproductive phenology of Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum throughout the early growing season of 2012 and, following a major harvest at peak season, we measured the biomass of above-ground ramet fractions. For all six years of soil warming we measured annual shoot growth of the three species and analyzed ramet age and xylem ring width of V. myrtillus. Our results show that phenology of the three species was more influenced by snowmelt timing, and also by plot tree species (Larix or Pinus) in the case of V. myrtillus, than by soil warming. However, the warming treatment led to increased V. myrtillus total above-ground ramet biomass (+36% in 2012), especially new shoot biomass (+63% in 2012), as well as increased new shoot increment length and xylem ring width (+22% and +41%, respectively; average for 2007-2012). These results indicate enhanced overall growth of V. myrtillus under soil warming that was sustained over six years and was not caused by an extended growing period in early summer. In contrast, E. hermaphroditum only showed a positive shoot growth response to warming in 2011 (+21%), and V. gaultherioides showed no significant growth response. Our results indicate that V. myrtillus might have a competitive advantage over the less responsive co-occurring dwarf shrub species under future global warming.

  8. Growth and phenology of three dwarf shrub species in a six-year soil warming experiment at the alpine treeline.

    Directory of Open Access Journals (Sweden)

    Alba Anadon-Rosell

    Full Text Available Global warming can have substantial impacts on the phenological and growth patterns of alpine and Arctic species, resulting in shifts in plant community composition and ecosystem dynamics. We evaluated the effects of a six-year experimental soil warming treatment (+4°C, 2007-2012 on the phenology and growth of three co-dominant dwarf shrub species growing in the understory of Larix decidua and Pinus uncinata at treeline in the Swiss Alps. We monitored vegetative and reproductive phenology of Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum throughout the early growing season of 2012 and, following a major harvest at peak season, we measured the biomass of above-ground ramet fractions. For all six years of soil warming we measured annual shoot growth of the three species and analyzed ramet age and xylem ring width of V. myrtillus. Our results show that phenology of the three species was more influenced by snowmelt timing, and also by plot tree species (Larix or Pinus in the case of V. myrtillus, than by soil warming. However, the warming treatment led to increased V. myrtillus total above-ground ramet biomass (+36% in 2012, especially new shoot biomass (+63% in 2012, as well as increased new shoot increment length and xylem ring width (+22% and +41%, respectively; average for 2007-2012. These results indicate enhanced overall growth of V. myrtillus under soil warming that was sustained over six years and was not caused by an extended growing period in early summer. In contrast, E. hermaphroditum only showed a positive shoot growth response to warming in 2011 (+21%, and V. gaultherioides showed no significant growth response. Our results indicate that V. myrtillus might have a competitive advantage over the less responsive co-occurring dwarf shrub species under future global warming.

  9. Effects of TiO{sub 2} nanoparticles on the growth and metabolism of three species of freshwater algae

    Energy Technology Data Exchange (ETDEWEB)

    Cardinale, Bradley J., E-mail: bradcard@umich.edu [University of Michigan, School of Natural Resources and Environment (United States); Bier, Raven [Duke University, Department of Biology (United States); Kwan, Courtney [Evolution and Marine Biology, University of California, Department of Ecology (United States)

    2012-08-15

    We examined how TiO{sub 2} nanoparticles (nTiO{sub 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{sub 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{sub 2}, with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO{sub 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{sub 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{sub 2} had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO{sub 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{sub 2} has potential to alter important community and ecosystem properties of freshwater habitats.

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

    Science.gov (United States)

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

    2012-08-01

    We examined how TiO2 nanoparticles ( nTiO2) 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 nTiO2 (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 nTiO2, with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO2 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, nTiO2 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, nTiO2 had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO2 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 nTiO2 has potential to alter important community and ecosystem properties of freshwater habitats.

  11. 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.

  12. 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.

  13. Limited growth recovery after drought-induced forest dieback in very defoliated trees of two pine species

    Directory of Open Access Journals (Sweden)

    Guillermo eGuada

    2016-04-01

    Full Text Available Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width and intra-annual (xylogenesis scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized three years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die.

  14. Modelling the growth of Populus species using Ecosystem Demography (ED) model

    Science.gov (United States)

    Wang, D.; Lebauer, D. S.; Feng, X.; Dietze, M. C.

    2010-12-01

    Hybrid poplar plantations are an important source being evaluated for biomass production. Effective management of such plantations requires adequate growth and yield models. The Ecosystem Demography model (ED) makes predictions about the large scales of interest in above- and belowground ecosystem structure and the fluxes of carbon and water from a description of the fine-scale physiological processes. In this study, we used a workflow management tool, the Predictive Ecophysiological Carbon flux Analyzer (PECAn), to integrate literature data, field measurement and the ED model to provide predictions of ecosystem functioning. Parameters for the ED ensemble runs were sampled from the posterior distribution of ecophysiological traits of Populus species compiled from the literature using a Bayesian meta-analysis approach. Sensitivity analysis was performed to identify the parameters which contribute the most to the uncertainties of the ED model output. Model emulation techniques were used to update parameter posterior distributions using field-observed data in northern Wisconsin hybrid poplar plantations. Model results were evaluated with 5-year field-observed data in a hybrid poplar plantation at New Franklin, MO. ED was then used to predict the spatial variability of poplar yield in the coterminous United States (United States minus Alaska and Hawaii). Sensitivity analysis showed that root respiration, dark respiration, growth respiration, stomatal slope and specific leaf area contribute the most to the uncertainty, which suggests that our field measurements and data collection should focus on these parameters. The ED model successfully captured the inter-annual and spatial variability of the yield of poplar. Analyses in progress with the ED model focus on evaluating the ecosystem services of short-rotation woody plantations, such as impacts on soil carbon storage, water use, and nutrient retention.

  15. Photosynthetic capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.

    Science.gov (United States)

    Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Niyonzima, Felix; Adolfsson, Lisa; Nsabimana, Donat; Uddling, Johan

    2015-04-01

    Photosynthetic capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the photosynthetic capacity of tropical trees, we collected data on photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in photosynthetic capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to photosynthetic capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in photosynthetic capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased photosynthetic capacity when grown in a warmer environment.

  16. Fifteen-Year Growth of Six Planted Hardwood Species on Sharkey Clay Soil

    Science.gov (United States)

    Roger M. Krinard; Harvey E. Kennedy

    1987-01-01

    Six hardwood species planted on Sharkey clay soil that had been disked the first 5 years for weed control were significantly taller at age 5 when compared to species grown on mowed sites. By age 15, there were no differences in heights within species except for sweet pecan. Average heights by species at age 15 were: cottonwood (Populus deltoides...

  17. Modeling population dynamics and economic growth as competing species. An application to CO2 global emissions

    International Nuclear Information System (INIS)

    Puliafito, Salvador Enrique; Puliafito, Jose Luis; Grand, Mariana Conte

    2008-01-01

    Since the beginning of the last century the world is experiencing an important demographic transition, which will probably impact on economic growth. Many demographers and social scientists are trying to understand the key drivers of such transition as well as its profound implications. A correct understanding will help to predict other important trends of the world primary energy demand and the carbon emission to the atmosphere, which may be leading to an important climate change. This paper proposes a set of coupled differential equations to describe the changes of population, gross domestic product, primary energy consumption and carbon emissions, modeled as competing species as in Lotka-Volterra prey-predator relations. The predator-prey model is well known in the biological, ecological and environmental literature and has also been applied successfully in other fields. This model proposes a new and simple conceptual explanation of the interactions and feedbacks among the principal driving forces leading to the present transition. The estimated results for the temporal evolution of world population, gross domestic product, primary energy consumption and carbon emissions are calculated from year 1850 to year 2150. The calculated scenarios are in good agreement with common world data and projections for the next 100 years. (author)

  18. Solvable single-species aggregation-annihilation model for chain-shaped cluster growth

    International Nuclear Information System (INIS)

    Ke Jianhong; Lin Zhenquan; Zheng Yizhuang; Chen Xiaoshuang; Lu Wei

    2007-01-01

    We propose a single-species aggregation-annihilation model, in which an aggregation reaction between two clusters produces an active cluster and an annihilation reaction produces an inert one. By means of the mean-field rate equation, we respectively investigate the kinetic scaling behaviours of three distinct systems. The results exhibit that: (i) for the general aggregation-annihilation system, the size distribution of active clusters consistently approaches the conventional scaling form; (ii) for the system with the self-degeneration of the cluster's activities, it takes the modified scaling form; and (iii) for the system with the self-closing of active clusters, it does not scale. Moreover, the size distribution of inert clusters with small size takes a power-law form, while that of large inert clusters obeys the scaling law. The results also show that all active clusters will eventually transform into inert ones and the inert clusters of any size can be produced by such an aggregation-annihilation process. This model can be used to mimic the chain-shaped cluster growth and can provide some useful predictions for the kinetic behaviour of the system

  19. 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.

  20. 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.

  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. 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...

  3. 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...

  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. 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

  6. 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...... there were differences in the pattern of growth of caterpillars from different populations during the first few months after adoption, which depended on host ant species and the site from which the ants were collected, there was no evidence of major differences in final size achieved. Survival was, however...

  7. Nutrient and mineral composition during shoot growth in seven species of Phyllostachys and Pseudosasa bamboo consumed by giant panda.

    Science.gov (United States)

    Christian, A L; Knott, K K; Vance, C K; Falcone, J F; Bauer, L L; Fahey, G C; Willard, S; Kouba, A J

    2015-12-01

    During the annual period of bamboo shoot growth in spring, free-ranging giant pandas feed almost exclusively on the shoots while ignoring the leaves and full- height culm. Little is known about the nutritional changes that occur during bamboo shoot growth, if nutritional changes differ among species, or how these changes might influence forage selection. Our objective was to examine the nutrient and mineral composition during three phases of shoot growth (180 cm) for seven species of bamboo (Phyllostachys (P.) aurea, P. aureosulcata, P. bissetii, P. glauca, P. nuda, P. rubromarginata, Pseudosasa japonica) fed to captive giant pandas at the Memphis Zoo. Total dietary fiber content of bamboo shoots increased (p 180 cm, while crude protein, fat and ash exhibited significant declines (p panda diets when available. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

  8. Growth and stable isotope signals associated with drought-related mortality in saplings of two coexisting pine species.

    Science.gov (United States)

    Herrero, Asier; Castro, Jorge; Zamora, Regino; Delgado-Huertas, Antonio; Querejeta, José I

    2013-12-01

    Drought-induced events of massive tree mortality appear to be increasing worldwide. Species-specific vulnerability to drought mortality may alter patterns of species diversity and affect future forest composition. We have explored the consequences of the extreme drought of 2005, which caused high sapling mortality (approx. 50 %) among 10-year-old saplings of two coexisting pine species in the Mediterranean mountains of Sierra Nevada (Spain): boreo-alpine Pinus sylvestris and Mediterranean P. nigra. Sapling height growth, leaf δ(13)C and δ(18)O, and foliar nitrogen concentration in the four most recent leaf cohorts were measured in dead and surviving saplings. The foliar isotopic composition of dead saplings (which reflects time-integrated leaf gas-exchange until mortality) displayed sharp increases in both δ(13)C and δ(18)O during the extreme drought of 2005, suggesting an important role of stomatal conductance (g(s)) reduction and diffusional limitations to photosynthesis in mortality. While P. nigra showed decreased growth in 2005 compared to the previous wetter year, P. sylvestris maintained similar growth levels in both years. Decreased growth, coupled with a sharper increase in foliar δ(18)O during extreme drought in dead saplings, indicate a more conservative water use strategy for P. nigra. The different physiological behavior of the two pine species in response to drought (further supported by data from surviving saplings) may have influenced 2005 mortality rates, which contributed to 2.4-fold greater survival for P. nigra over the lifespan of the saplings. This species-specific vulnerability to extreme drought could lead to changes in dominance and distribution of pine species in Mediterranean mountain forests.

  9. 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.

  10. Effect of holothurian and zoanthid extracts on growth of some bacterial and diatom species

    Digital Repository Service at National Institute of Oceanography (India)

    Gonsalves, C.

    The antifouling properties of the extracts from two zoanthids, viz. Zoanthus sp, Protopalythoa sp and one holothurian species, viz. Holothuria leucospilota occurring in the coastal waters off Goa were tested against 5 bacteria and 2 diatom species...

  11. Directional growth of a clonal bromeliad species in response to spatial habitat heterogeneity

    NARCIS (Netherlands)

    Sampaio, M.C.; Araujo, T.F.; Scarano, F.R.; Stuefer, J.F.

    2004-01-01

    Habitat selection by directional growth of plants has previously been investigated but field evidence for this phenomenon is extremely scarce. In this study we demonstrate directional clonal growth in Aechmea nudicaulis, a monocarpic, perennial bromeliad native to spatially heterogeneous sandy

  12. 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.

  13. 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.

  14. Growth response of four species of Eastern hardwood tree seedlings exposed to ozone, acidic precipitation, and sulfur dioxide

    International Nuclear Information System (INIS)

    Davis, D.D. Skelly, J.M.

    1992-01-01

    In 1987 a study was conducted in controlled environment chambers to determine the foliar sensitivity of tree seedlings of eight species to ozone and acidic precipitation, and to determine the influence of leaf position on symptom severity. Jensen and Dochinger conducted concurrent similar studies in Continuously Stirred Tank Reactor (CSTR) chambers with ten species of forest trees. Based on the results of these initial studies, four species representing a range in foliar sensitivity to ozone were chosen: black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.). These species were also chosen because of their ecological and/or commercial importance in Pennsylvania. Seedlings were exposed in growth chambers simulated acid rain. In addition acute exposures to sulfur dioxide were conducted in a regime based on unpublished monitoring data collected near coal-fired power plants. The objective of this study was to determine if the pollutant treatments influenced the growth and productivity of seedlings of these four species. This information will help researchers and foresters understand the role of air pollution in productivity of eastern forests

  15. Genetic Diversity of Nitrogen-Fixing and Plant Growth Promoting Pseudomonas Species 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

  16. Consistent treatment of ground deposition together with species growth and decay during atmospheric transport

    International Nuclear Information System (INIS)

    Murphy, B.D.; Nelson, C.B.; Ohr, S.Y.

    1981-01-01

    We discuss the adaptation of a trajectory model to an initial pollutant species and a series of successor species at mesoscale distances. The effect of source height is discussed since it is important in determining close-in ground level concentration, which influences plume depletion due to dry deposition. A scheme is outlined which handles deposition and species decay in a consistent manner and which does so for an arbitrary number of successor pollutant species. This scheme is discussed in terms of a Lagrangian trajectory model which accounts for initial source height and which calculates ground-level concentrations out to mesoscale distances

  17. 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.

  18. Comparative study of mycelial growth and basidiomata formation in seven different species of the edible mushroom genus Hericium.

    Science.gov (United States)

    Ko, Han Gyu; Park, Hyuk Gu; Park, Sang Ho; Choi, Chang Won; Kim, Seong Hwan; Park, Won Mok

    2005-09-01

    The potential of using several agricultural by-products as supplements of sawdust substrate for the production of edible mushroom Hericium was evaluated using seven Hericium species. All the tested supplements (rice bran, wheat bran, barley bran, Chinese cabbage, egg shell, and soybean powder) were found to be suitable for the mycelial growth of all the tested species. In mycelial growth, soybean powder was the best supplement for Hericium americanum, Hericium coralloides, and Hericium erinaceum while barley bran was the best for Hericium alpestre, Hericium laciniatum, and Hericium erinaceus. For Hericium abietis, rice bran and Chinese cabbage was the best. The possibility of mushroom production on oak sawdust substrate with 20% rice bran supplement was demonstrated with H. coralloides, H. americanum, H. erinaceus, and H. erinaceum which showed 26-70% biological efficiency. Our results also showed that strain selection is important to improve biological efficiency and mushroom yield in Hericium cultivation.

  19. Allelopathic effects of Sonchus oleraceus L. on the germination and seedling growth of crop and weed species

    OpenAIRE

    Gomaa,Nasr Hassan; Hassan,Mahmoud Omar; Fahmy,Gamal Mohammad; González,Luís; Hammouda,Ola; Atteya,Atteya Mostafa

    2014-01-01

    We assessed the allelopathic effects of the aqueous extract of Sonchus oleraceus dry shoots on the germination and seedling growth of Trifolium alexandrinum, three weed species (Brassica nigra, Chenopodium murale and Melilotus indicus) and S. oleraceus itself. We assayed four different concentrations of the aqueous extract (w v-1): 1%, 2%, 3% and 4%. To determine whether the effects of the extract were attributable to the presence of allelopathic compounds, its osmotic potential or both, we p...

  20. 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

  1. 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

    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...

  2. 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.

  3. 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

  4. Sediment and Nutrient Sources as well as Interspecific Competition Control Growth of 2 Common Species of Coral Reef Macroalgae

    Science.gov (United States)

    Moore, T.; Fong, P.; Cuker, B.

    2016-02-01

    Aquatic communities worldwide are increasingly subjected to multiple anthropogenic stressors that often result in shifts in structure and function. On coral reefs, human impacts have been associated with phase-shifts from coral to algal domination. We hypothesized that the proliferation of these algal communities, especially on fringing reefs, may be facilitated by human alterations in nutrient enrichment and input of sediments from developed watersheds, which may also influence competitive outcomes among dominant algal species. To evaluate how changes in these abiotic stressors as well as competition may affect the growth of 2 common species of calcifying coral reef algae, Galaxaura fasciculata and Padina boryana, we conducted 3 separate 2 factor mesocosm experiments modeling fringing reefs in Moorea, French Polynesia. In the first experiment, we varied sediment source (marine vs. terrestrial) and water column nutrients (ambient vs. enriched) for each species separately and measured growth after 7 days. While both algae grew faster in enriched compared to ambient nutrients, P. boryana performed best with marine sediment (+27% change in biomass) and G. fasciculata with terrestrial sediment (+14% change in biomass). Next, we varied sediment source (as above) as well as sediment nutrients (ambient/enriched) for each species. While P. boryana lost 44% biomass in the eutrophic terrestrial sediment treatment, G. fasciculata performed the best and gained 19% biomass. Finally, we varied competition (alone/together) and terrestrial sediment nutrients (ambient/enriched). Over the 7 day period, P. boryana lost 64% biomass when in competition with G. fasciculata in the enriched treatment while G. fasciculata gained 38% biomass when in competition with P. boryana in the ambient treatment. These results indicate that, while growth of both species of macroalgae was regulated by nutrients, sediments, and competition, each responded uniquely to these controlling factors.

  5. Insights into intraspecific wood density variation and its relationship to growth, height and elevation in a treeline species.

    Science.gov (United States)

    Fajardo, A

    2018-05-01

    The wood economics spectrum provides a general framework for interspecific trait-trait coordination across wide environmental gradients. Whether global patterns are mirrored within species constitutes a poorly explored subject. In this study, I first determined whether wood density co-varies together with elevation, tree growth and height at the within-species level. Second, I determined the variation of wood density in different stem parts (trunk, branch and twigs). In situ trunk sapwood, trunk heartwood, branch and twig densities, in addition to stem growth rates and tree height were determined in adult trees of Nothofagus pumilio at four elevations in five locations spanning 18° of latitude. Mixed effects models were fitted to test relationships among variables. The variation in wood density reported in this study was narrow (ca. 0.4-0.6 g cm -3 ) relative to global density variation (ca. 0.3-1.0 g cm -3 ). There was no significant relationship between stem growth rates and wood density. Furthermore, the elevation gradient did not alter the wood density of any stem part. Trunk sapwood density was negatively related to tree height. Twig density was higher than branch and trunk densities. Trunk heartwood density was always significantly higher than sapwood density. Negative across-species trends found in the growth-wood density relationship may not emerge as the aggregate of parallel intraspecific patterns. Actually, trees with contrasting growth rates show similar wood density values. Tree height, which is tightly related to elevation, showed a negative relationship with sapwood density. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  6. 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.

  7. Adaptation of the fish juvenile growth test (OECD TG 215, 2000) to the marine species Dicentrarchus labrax.

    Science.gov (United States)

    Tornambè, A; Manfra, L; Canepa, S; Oteri, F; Martuccio, G; Cicero, A M; Magaletti, E

    2018-02-01

    The OECD TG 215 method (2000) (C.14 method of EC Regulation 440/2008) was developed on the rainbow trout (Oncorynchus mykiss) to assess chronic toxicity (28d) of chemicals on fish juveniles. It contemplates to use other well documented species identifying suitable conditions to evaluate their growth. OECD proposes the European sea bass (Dicentrarchus labrax, L. 1758) as Mediterranean species among vertebrates recommended in the OECD guidelines for the toxicity testing of chemicals. In this context, our study is aimed to proposing the adaptation of the growth test (OECD TG 215, 2000) to D. labrax. For this purpose toxicity tests were performed with sodium dodecyl sulfate, a reference toxicant commonly used in fish toxicity assays. The main aspects of the testing procedure were reviewed: fish size (weight), environmental conditions, dilution water type, experimental design, loading rate and stocking density, feeding (food type and ration), test validity criteria. The experience gained from growth tests with the sea bass allows to promote its inclusion among the species to be used for the C.14 method. Copyright © 2016. Published by Elsevier Inc.

  8. 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.

  9. Influence of 50 Hz magnetic field on growth of mushroom species: Shitake (Lentinus edodes) and Oyster (Pleurotus astreatus)

    Energy Technology Data Exchange (ETDEWEB)

    Bambang Anggoro; Pakpahan, P.M.; Fajar Dwi Kusnoaji; Sirait, K.T. [Bandung Institute of Technology (Indonesia). Faculty of Industrial Technology

    1999-07-01

    Investigation on effects of electromagnetic fields on different aspects of biological systems has been done by much research. Our present study, which has been carried out under the joint research between the laboratory of High voltage and High current Engineering and the Laboratory of Microbiology of Institut Teknologi Bandung, investigates the influence of 50 Hz magnetic field on the growth of several species of mushroom. In this study, we observed growth of mushroom, from spora up to fully ripped stages, under magnetic field exposure of different intensity from 0,1 mT to 1,7 mT. During exposure the room condition was held constant at a temperature of 20{sup o}C and 95% humidity. We noted that some parameters such as: mushroom growth velocity, shape, dimension, quantity, color and period of mushroom ovary are significantly influenced by magnetic energy absorbed. (author)

  10. Influence of photoperiod on growth for three desert CAM species. [Agave deserti, Ferocactus acanthodes, Opuntia ficus-indica

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S. (Univ. of California, Los Angeles (USA))

    1989-03-01

    Agave deserti, Ferocactus acanthodes, and Opuntia ficus-indica were maintained in environmental growth chambers under a constant total daily photosynthetically active radiation (PAR) for 1 yr to investigate the effects of photoperiod on growth of these Crassulacean acid metabolism (CAM) species. As the photoperiod was increased from 6 h to 18 h, growth increased 33% for A. deserti, 81% for F. acanthodes, and 50% for O. ficus-indica. Such increases were explained based on PAR saturation of the C{sub 3} photosynthetic carbon reduction cycle utilized by CAM plants during the daytime. In particular, the highest instantaneous PAR occurred for the shortest photoperiod and led to less growth for the same total daily PAR. Also, the total daily net CO{sub 2} uptake which occurred primarily at night, increased 53% as the photoperiod was increased from 6 to 18 h for O. ficus-indica, even though the accompanying night length decreased. The only other observed morphological effect was the sevenfold increase in the number of new cladodes initiated as the photoperiod was increased from 6 h to 18 h for O. ficus-indica. The influence of photoperiod on the daily pattern of net CO{sub 2} uptake and lack of effect of drought on plant survival under long photoperiods for O. ficus-indica differ from previous reports on this and other CAM species.

  11. 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.

  12. Postsettlement growth of two estuarine crab species, Chasmagnathus granulata and Cyrtograpsus angulatus (Crustacea, Decapoda, Grapsidae): laboratory and field investigations

    Science.gov (United States)

    Luppi, T. A.; Spivak, E. D.; Anger, K.

    2002-02-01

    The estuarine grapsid crabs Chasmagnathus granulata and Cyrtograpsus angulatus belong to the most typical and dominant inhabitants of brackish coastal lagoons in southeastern South America. In a combined laboratory and field investigation of juvenile growth, we measured the increase in body size in these species under controlled conditions as well as in field experiments (in Mar Chiquita lagoon, Argentina), seasonal changes in size frequency distribution of a natural population, and growth related changes in selected morphometric traits of male and female juveniles (relations between carapace width, carapace length, propodus height and length of the cheliped, and pleon width). At 24°C, Cy. angulatus grew faster than Ch. granulata; it reached the crab-9 instar (C9; 13 mm carapace width) after 92 days, while Ch. granulata required 107 days to reach the C8 instar (7.4 mm). At 12°C, growth ceased in both species. The pleon begins to show sexual differences in the C5 ( Cy. angulatus) and C8 instar ( Ch. granulata), respectively, while the chelae differentiate earlier in Ch. granulata than in Cy. angulatus (in C4 vs C6). In the field, growth was maximal in summer, and was generally faster than in laboratory cultures. However, there is great individual variability in size (about 25% even in the first crab instar) and in size increments at ecdysis, increasing throughout juvenile growth. Our data indicate that, in the field, small-scale and short-term variations in feeding conditions, temperature, and salinity account for an extremely high degree of variability in the absolute and relative rates of growth as well as in the time to sexual differentiation.

  13. 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.

  14. Growth of transplanted seedlings of timber species in the southern Colombian Amazon: a preliminary study

    International Nuclear Information System (INIS)

    Gruezmacher Monica; Duivenvoorden Joost F

    2008-01-01

    Two commonly used timber species in the area of Amacayacu National Park (Quararibea sp. and Minquartia guianensis) were selected to develop an experiment that compared the early performance of seedlings in mature and old secondary forest. We transplanted seedlings of these species into mature and secondary forest plots and observed height and diameter increments as well as mortality for a period of approximately 70 days. In situ seedling performance under parent trees in mature forests was measured as a control. The structure of both experimental forests was not apparently different.We found similar seedling performance for both species in the two forests. However, the seedlings hardly showed any relative height or relative diameter increment in the short period of measurements. The results show that enriching secondary forests by means of transplanting seedlings from timber species might be a promising way of ecological restoration.

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

    African Journals Online (AJOL)

    aghomotsegin

    2015-02-11

    Feb 11, 2015 ... Key words: Cyprinus carpio, common carp, eggs, mycotal species, infections, ..... Woo PTK, Bruno DW (Eds.) Fish Diseases and Disorders. Viral, ... like organism developing on the eggs of pink salmon Oncorhynchus.

  16. 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.

  17. Carbon source-sink limitations differ between two species with contrasting growth strategies.

    Science.gov (United States)

    Burnett, Angela C; Rogers, Alistair; Rees, Mark; Osborne, Colin P

    2016-11-01

    Understanding how carbon source and sink strengths limit plant growth is a critical knowledge gap that hinders efforts to maximize crop yield. We investigated how differences in growth rate arise from source-sink limitations, using a model system comparing a fast-growing domesticated annual barley (Hordeum vulgare cv. NFC Tipple) with a slow-growing wild perennial relative (Hordeum bulbosum). Source strength was manipulated by growing plants at sub-ambient and elevated CO 2 concentrations ([CO 2 ]). Limitations on vegetative growth imposed by source and sink were diagnosed by measuring relative growth rate, developmental plasticity, photosynthesis and major carbon and nitrogen metabolite pools. Growth was sink limited in the annual but source limited in the perennial. RGR and carbon acquisition were higher in the annual, but photosynthesis responded weakly to elevated [CO 2 ] indicating that source strength was near maximal at current [CO 2 ]. In contrast, photosynthetic rate and sink development responded strongly to elevated [CO 2 ] in the perennial, indicating significant source limitation. Sink limitation was avoided in the perennial by high sink plasticity: a marked increase in tillering and root:shoot ratio at elevated [CO 2 ], and lower non-structural carbohydrate accumulation. Alleviating sink limitation during vegetative development could be important for maximizing growth of elite cereals under future elevated [CO 2 ]. © 2016 John Wiley & Sons Ltd.

  18. Reactive oxygen species are involved in lipopolysaccharide-induced intrauterine growth restriction and skeletal development retardation in mice.

    Science.gov (United States)

    Xu, De-Xiang; Chen, Yuan-Hua; Zhao, Lei; Wang, Hua; Wei, Wei

    2006-12-01

    Maternal infection is a cause of adverse developmental outcomes including embryonic resorption, intrauterine fetal death, and preterm labor. Lipopolysaccharide-induced developmental toxicity at early gestational stages has been well characterized. The purpose of the present study was to investigate the effects of maternal lipopolysaccharide exposure at late gestational stages on intrauterine fetal growth and skeletal development and to assess the potential role of reactive oxygen species in lipopolysaccharide-induced intrauterine fetal growth restriction and skeletal development retardation. The timed pregnant CD-1 mice were intraperitoneally injected with lipopolysaccharide (25 to 75 microg/kg per day) on gestational day 15 to 17. To investigate the role of reactive oxygen species on lipopolysaccharide-induced intrauterine fetal growth restriction and skeletal development retardation, the pregnant mice were injected with alpha-phenyl-N-t-butylnitrone (100 mg/kg, intraperitoneally) at 30 minutes before lipopolysaccharide (75 microg/kg per day, intraperitoneally), followed by an additional dose of alpha-phenyl-N-t-butylnitrone (50 mg/kg, intraperitoneally) at 3 hours after lipopolysaccharide. The number of live fetuses, dead fetuses, and resorption sites was counted on gestational day 18. Live fetuses in each litter were weighed. Crown-rump and tail lengths were examined and skeletal development was evaluated. Maternal lipopolysaccharide exposure significantly increased fetal mortality, reduced fetal weight and crown-rump and tail lengths of live fetuses, and retarded skeletal ossification in caudal vertebrae, anterior and posterior phalanges, and supraoccipital bone in a dose-dependent manner. Alpha-phenyl-N-t-butylnitrone, a free radical spin-trapping agent, almost completely blocked lipopolysaccharide-induced fetal death (63.2% in lipopolysaccharide group versus 6.5% in alpha-phenyl-N-t-butylnitrone + lipopolysaccharide group, P intrauterine growth restriction

  19. 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.

  20. 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

  1. Nutritional ecology of the Formosan subterranean termite (Isoptera: Rhinotermitidae): growth and survival of incipient colonies feeding on preferred wood species.

    Science.gov (United States)

    Morales-Ramos, Juan A; Rojas, M Guadalupe

    2003-02-01

    The wood of 11 plant species was evaluated as a food source significantly impacting the growth and survival of incipient colonies of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Colonies of C. formosanus feeding on pecan, Carya illinoensis (Wangenh.), and red gum, Liquidambar styraciflua L., produced significantly more progeny than colonies feeding on other wood species tested. Progeny of colonies feeding on pecan and American ash, Fraxinus americana L., had significantly greater survival than progeny of colonies feeding on other wood species. Colonies feeding on a nutritionally supplemented cellulose based matrix showed similar fitness characteristics as colonies feeding on the best wood treatments. These results indicate that differences observed in colony fitness can be partially explained by nutritional value of the food treatment, raising the possibility that wood from different tree species have different nutritional values to the Formosan subterranean termites. Colonies feeding on loblolly pine, Pinus taeda L., and ponderosa pine, Pinus ponderosa Laws., had significantly lower survival and produced significantly fewer workers and soldiers than colonies feeding on other wood species. Colony survival from 90 to 180 d of age and from 90 to 360 d of age was significantly correlated with the number of workers present at 90 d of colony age, indicating that colony survival depends on the presence of workers. Wood consumption in a multiple-choice study was significantly correlated with colony fitness value. This suggests that feeding preference of C. formosanus is at least partially influenced by the nutritional value of the food source.

  2. 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.

  3. 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

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

    Science.gov (United States)

    Mendivelso, Hooz A; Camarero, J Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    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.

  5. 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.

  6. Differential Growth Responses to Water Balance of Coexisting Deciduous Tree Species Are Linked to Wood Density in a Bolivian Tropical Dry Forest

    Science.gov (United States)

    Mendivelso, Hooz A.; Camarero, J. Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    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. PMID:24116001

  7. 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 (g s) 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 (δ(13)C) 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.

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

    Directory of Open Access Journals (Sweden)

    Raju Yaranna Soolanayakanahally

    2015-07-01

    Full Text Available 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 P. 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. In doing so, 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.

  9. Growth temperature and dopant species effects on deep levels in Si grown by low temperature molecular beam epitaxy

    International Nuclear Information System (INIS)

    Chung, Sung-Yong; Jin, Niu; Rice, Anthony T.; Berger, Paul R.; Yu, Ronghua; Fang, Z-Q.; Thompson, Phillip E.

    2003-01-01

    Deep-level transient spectroscopy measurements were performed in order to investigate the effects of substrate growth temperature and dopant species on deep levels in Si layers during low-temperature molecular beam epitaxial growth. The structures studied were n + -p junctions using B doping for the p layer and p + -n junctions using P doping for the n layer. While the density of hole traps H1 (0.38-0.41 eV) in the B-doped p layers showed a clear increase with decreasing growth temperature from 600 to 370 degree sign C, the electron trap density was relatively constant. Interestingly, the minority carrier electron traps E1 (0.42-0.45 eV) and E2 (0.257 eV), found in the B-doped p layers, are similar to the majority carrier electron traps E11 (0.48 eV) and E22 (0.269 eV) observed in P-doped n layers grown at 600 degree sign C. It is hypothesized that these dominating electron traps are associated with pure divacancy defects and are independent of the dopant species

  10. Effect of Aqueous Extracts from Weed Species on Germination and Initial Growth in Raphanus sativus L.

    Directory of Open Access Journals (Sweden)

    Anisoara STRATU

    2015-12-01

    Full Text Available The current paper presents the results of a study on the effects of aqueous extracts from five weed species (Amaranthus retroflexus, Cirsium arvense, Convolvulus arvensis, Echinochloa crus-galii, Setaria verticillata on germination and initial growth in Raphanus sativus L. The following indicators have been analyzed: indices of germination (the germination percentage; the speed of germination; the speed of accumulated germination and the coefficient of germination rate, the length of the root and hypocotyls, the pH of aqueous extracts, the UV-Vis absorption spectra of aqueous extracts. The results of the investigations showed the following aspects: the aqueous extracts reduced the values of calculated germination indices and root growth in the first ontogenetic stages of the test species; the pH of the extracts was slightly acid to neutral. Qualitative spectrophotometric analysis indicated the possible presence of phenolic and organic compounds in the extracts. C. arvense, S. verticillata and E. crus-galii presented the most pronounced effect on germination and growth processes.

  11. [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.

  12. 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

  13. 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...

  14. 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...

  15. 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.

  16. 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...

  17. Convergent development of a parasitoid wasp on three host species with differing mass and growth potential

    NARCIS (Netherlands)

    Harvey, J.A.; Molina, A.C.; Bezemer, T.M.; Malcicka, M.

    2015-01-01

    Koinobiont parasitoids develop in hosts that continue feeding and growing during the course of parasitism. Here, we compared development of a solitary koinobiont endoparasitoid, Meteorus pulchricornis Westmael (Hymenoptera: Braconidae), in second (L2) and fourth (L4) instars of three host species

  18. 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

  19. 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

    grown as nutrient-replete semicontinuous cultures for 2 weeks at 5, 15 and 25°C, during which growth rate was determined from changes in Chl a. Gross photosynthesis (GP) was measured as 14C assimilation at saturating light and respiration (R) was measured as O2 uptake along a temperature gradient from 0...

  20. 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

  1. 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.

  2. Chlamydia species-dependent differences in the growth requirement for lysosomes.

    Directory of Open Access Journals (Sweden)

    Scot P Ouellette

    2011-03-01

    Full Text Available Genome reduction is a hallmark of obligate intracellular pathogens such as Chlamydia, where adaptation to intracellular growth has resulted in the elimination of genes encoding biosynthetic enzymes. Accordingly, chlamydiae rely heavily on the host cell for nutrients yet their specific source is unclear. Interestingly, chlamydiae grow within a pathogen-defined vacuole that is in close apposition to lysosomes. Metabolically-labeled uninfected host cell proteins were provided as an exogenous nutrient source to chlamydiae-infected cells, and uptake and subsequent labeling of chlamydiae suggested lysosomal degradation as a source of amino acids for the pathogen. Indeed, Bafilomycin A1 (BafA1, an inhibitor of the vacuolar H(+/ATPase that blocks lysosomal acidification and functions, impairs the growth of C. trachomatis and C. pneumoniae, and these effects are especially profound in C. pneumoniae. BafA1 induced the marked accumulation of material within the lysosomal lumen, which was due to the inhibition of proteolytic activities, and this response inhibits chlamydiae rather than changes in lysosomal acidification per se, as cathepsin inhibitors also inhibit the growth of chlamydiae. Finally, the addition of cycloheximide, an inhibitor of eukaryotic protein synthesis, compromises the ability of lysosomal inhibitors to block chlamydial growth, suggesting chlamydiae directly access free amino acids in the host cytosol as a preferred source of these nutrients. Thus, chlamydiae co-opt the functions of lysosomes to acquire essential amino acids.

  3. Growth

    Science.gov (United States)

    John R. Jones; George A. Schier

    1985-01-01

    This chapter considers aspen growth as a process, and discusses some characteristics of the growth and development of trees and stands. For the most part, factors affecting growth are discussed elsewhere, particularly in the GENETICS AND VARIATION chapter and in chapters in PART 11. ECOLOGY. Aspen growth as it relates to wood production is examined in the WOOD RESOURCE...

  4. 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

    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...... 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...

  5. Effects of fluoride on germination, early growth and antioxidant enzyme activities of legume plant species Prosopis juliflora.

    Science.gov (United States)

    Saini, Poonam; Khan, Suphiya; Baunthiyal, Mamta; Sharma, Vinay

    2013-03-01

    Prosopis juliflora (Mimosoideae) is a fast growing and drought resistant tree of semi-arid region of India where fluoride (F) toxicity is a common problem. In the present investigations this species was fluoride tested to check their capacity as bioindicator plant and its efficiency to accumulate. To achieve this aim, P. juliflora seedlings grown in hydroponic culture containing different concentrations of F were analyzed for germination percentage together with some biochemical parameters viz, antioxidant enzyme activities, total chlorophyll and accumulation of F in different plant parts. After 15 days of treatment, root growth (r = -0.928, p juliflora did not show any morphological changes (marginal and tip chlorosis of leaf portions, necrosis and together these features are referred to as leaf "tip-burn") therefore, this species may be used as suitable bioindicator species for potentially F affected areas. Further, higher accumulation of F in roots indicates that P. juliflora is a suitable species for the removal of F in phytoremediation purposes.

  6. Allelopathic effects of Sonchus oleraceus L. on the germination and seedling growth of crop and weed species

    Directory of Open Access Journals (Sweden)

    Nasr Hassan Gomaa

    2014-09-01

    Full Text Available We assessed the allelopathic effects of the aqueous extract of Sonchus oleraceus dry shoots on the germination and seedling growth of Trifolium alexandrinum, three weed species (Brassica nigra, Chenopodium murale and Melilotus indicus and S. oleraceus itself. We assayed four different concentrations of the aqueous extract (w v-1: 1%, 2%, 3% and 4%. To determine whether the effects of the extract were attributable to the presence of allelopathic compounds, its osmotic potential or both, we prepared concentrations of polyethylene glycol (PEG with osmotic potentials equivalent to those of the aqueous extract. All concentrations of the plant extract completely inhibited the germination and seedling growth of C. murale. The lowest concentration of the plant extract partially inhibited germination and seedling growth of B. nigra, M. indicus and S. oleraceus, whereas the higher concentrations inhibited those parameters completely. The germination of T. alexandrinum was not affected by the aqueous extract at 1% or 2%. In general, the aqueous extracts were more effective in inhibiting seed germination and seedling growth than were the PEG solutions. Phytochemical analyses revealed that phenols and alkaloids were the most abundant compounds in S. oleraceus dry matter. Our results suggest that the aqueous extract of S. oleraceus has an allelopathic effect on some weeds, and its usefulness as a bioherbicide therefore merits further study.

  7. 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.

  8. 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.

  9. 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.

  10. 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...... (DCAA), natural organic matter (NOM)) or with nitrate as the sole nitrogen source. Monocultures of Chlamydomonas spp., Cyclotella meneghiniana, Microcystis aeruginosa and Anabaena flos-aquae were incubated with dissolved nitrogen compounds at concentrations ranging from 0.01 to 0.5 mg N L−1, which...... 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...

  11. 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.

  12. Morphological responses of crop and weed species of different growth forms to ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Barnes, P.W.; Flint, S.D.; Caldwell, M.M.

    1990-01-01

    The influence of ultraviolet-B (UV-B) radiation (280-320 nanometers) on the morphology of 12 common dicot and monocot crop or weed species was examined to determine whether any common responses could be found that might, in turn, be useful in predicting possible changes in competitive balance under solar UV-B enhancement. Under glasshouse conditions, UV-B exposure (simulating a 20% reduction in stratospheric ozone at Logan, Utah) was found to reduce leaf blade and internode lengths and increase leaf and axillary shoot production in several species. Overall, the directions of these trends were similar in the majority of species that exhibited a significant response. These morphological changes occurred without any significant reduction in total shoot dry matter production. There was no clear distinction in the response of crops and weeds, though monocots were found to be generally more responsive than dicots. Previous work in dense canopies has shown that the photomorphogenetic effects of UV-B alter leaf placement and thereby influence competition for light. Our results suggest that, under these conditions, changes in competitive balance resulting from increased UV-B might be expected more frequently when monocots are involved in mixtures, rather than mixtures of only dicots

  13. 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.

  14. Light requirements of Australian tropical vs. cool-temperate rainforest tree species show different relationships with seedling growth and functional traits.

    Science.gov (United States)

    Lusk, Christopher H; Kelly, Jeff W G; Gleason, Sean M

    2013-03-01

    A trade-off between shade tolerance and growth in high light is thought to underlie the temporal dynamics of humid forests. On the other hand, it has been suggested that tree species sorting on temperature gradients involves a trade-off between growth rate and cold resistance. Little is known about how these two major trade-offs interact. Seedlings of Australian tropical and cool-temperate rainforest trees were grown in glasshouse environments to compare growth versus shade-tolerance trade-offs in these two assemblages. Biomass distribution, photosynthetic capacity and vessel diameters were measured in order to examine the functional correlates of species differences in light requirements and growth rate. Species light requirements were assessed by field estimation of the light compensation point for stem growth. Light-demanding and shade-tolerant tropical species differed markedly in relative growth rates (RGR), but this trend was less evident among temperate species. This pattern was paralleled by biomass distribution data: specific leaf area (SLA) and leaf area ratio (LAR) of tropical species were significantly positively correlated with compensation points, but not those of cool-temperate species. The relatively slow growth and small SLA and LAR of Tasmanian light-demanders were associated with narrow vessels and low potential sapwood conductivity. The conservative xylem traits, small LAR and modest RGR of Tasmanian light-demanders are consistent with selection for resistance to freeze-thaw embolism, at the expense of growth rate. Whereas competition for light favours rapid growth in light-demanding trees native to environments with warm, frost-free growing seasons, frost resistance may be an equally important determinant of the fitness of light-demanders in cool-temperate rainforest, as seedlings establishing in large openings are exposed to sub-zero temperatures that can occur throughout most of the year.

  15. Link Between Capacity for Current Production and Syntrophic Growth in Geobacter species

    Directory of Open Access Journals (Sweden)

    Amelia-Elena eRotaru

    2015-07-01

    Full Text Available Electrodes are unnatural electron acceptors, and it is yet unknown how some Geobacter species evolved to use electrodes as terminal electron acceptors. Analysis of different Geobacter species revealed that they varied in their capacity for current production. G. metallireducens and G. hydrogenophilus generated high current densities (ca. 0.05 mA/cm2, comparable to G. sulfurreducens. G. bremensis, G. chapellei, G. humireducens, and G. uranireducens, produced much lower currents (ca. 0.05 mA/cm2 and G. bemidjiensis was previously found to not produce current. There was no correspondence between the effectiveness of current generation and Fe(III oxide reduction rates. Some high-current-density strains (G. metallireducens and G. hydrogenophilus reduced Fe(III-oxides as fast as some low-current-density strains (G. bremensis, G. humireducens, and G. uranireducens whereas other low-current-density strains (G. bemidjiensis and G. chapellei reduced Fe(III oxide as slowly as G. sulfurreducens, a high-current-density strain. However, there was a correspondence between the ability to produce higher currents and the ability to grow syntrophically. G. hydrogenophilius was found to grow in co-culture with Methanosarcina barkeri, which is capable of direct interspecies electron transfer (DIET, but not with Methanospirillium hungatei capable only of H2 or formate transfer. Conductive granular activated carbon (GAC stimulated metabolism of the G. hydrogenophilus - M. barkeri co-culture, consistent with electron exchange via DIET. These findings, coupled with the previous finding that G. metallireducens and G. sulfurreducens are also capable of DIET, suggest that evolution to optimize DIET has fortuitiously conferred the capability for high-density current production to some Geobacter species.

  16. Effect of Bacillus Species Rhizobacteria on Kabuli Chickpea Plants Growth under Pots and Field Conditions

    OpenAIRE

    Ait Kaki, Asma; Benhassine, Sara; Milet, Asma; Kara Ali, Monira; Moula, Nassim; Kacem Chaouche, Nordine

    2018-01-01

    In the present research, some Bacillus strains were produced at the industrial scale in order to be tested on chickpea growth, under pots and field conditions. Bacteria reached high sporulation yields ranging from 0.8×109-2.5×109 and 8×109-10×109 spores mL-1 in flasks and 500 L bioreactor culture conditions, respectively. Under pots experiment, B. amyloliquefaciens (9SRTS) and B. amyloliquefaciens (CWBI) increased significantly the root mass (0.31 and 0.37 vs. 0.066 g, respectively) and reduc...

  17. Role of platelet-released growth factors in detoxification of reactive oxygen species in osteoblasts.

    Science.gov (United States)

    Tohidnezhad, Mersedeh; Wruck, Christoph-Jan; Slowik, Alexander; Kweider, Nisreen; Beckmann, Rainer; Bayer, Andreas; Houben, Astrid; Brandenburg, Lars-Ove; Varoga, Deike; Sönmez, Tolga-Taha; Stoffel, Marcus; Jahr, Holger; Lippross, Sebastian; Pufe, Thomas

    2014-08-01

    Oxidative stress can impair fracture healing. To protect against oxidative damage, a system of detoxifying and antioxidative enzymes works to reduce the cellular stress. The transcription of these enzymes is regulated by antioxidant response element (ARE). The nuclear factor (erythroid-derived 2)-like2 (Nrf2) plays a major role in transcriptional activation of ARE-driven genes. Recently it has been shown that vascular endothelial growth factor (VEGF) prevents oxidative damage via activation of the Nrf2 pathway in vitro. Platelet-released growth factor (PRGF) is a mixture of autologous proteins and growth factors, prepared from a determined volume of platelet-rich plasma (PRP). It has already used to enhance fracture healing in vitro. The aim of the present study was to elucidate if platelets can lead to upregulation of VEGF and if platelets can regulate the activity of Nrf2-ARE system in primary human osteoblast (hOB) and in osteoblast-like cell line (SAOS-2). Platelets and PRGF were obtained from healthy human donors. HOB and SAOS-2 osteosarcoma cell line were used. The ARE activity was analysed using a dual luciferase reporter assay system. We used Western blot to detect the nuclear accumulation of Nrf2 and the amount of cytosolic antioxidant Thioredoxin Reductase-1 (TXNRD-1), Heme Oxygenase-1 (HO-1) and NAD(P)H quinine oxidoreductase-1 (NQO1). Gene expression analysis was performed by real-time RT PCR. ELISA was used for the quantification of growth factors. The activity of ARE was increased in the presence of PRGF up to 50%. Western blotting demonstrated enhanced nuclear accumulation of Nrf2. This was followed by an increase in the protein expression of the aforementioned downstream targets of Nrf2. Real-time RT PCR data showed an upregulation in the gene expression of the VEGF after PRGF treatment. This was confirmed by ELISA, where the treatment with PRGF induced the protein level of VEGF in both cells. These results provide a new insight into PRGF's mode of

  18. Surveying some strategies of cultural management on species growth indices and yield in the field of soybean

    Directory of Open Access Journals (Sweden)

    habibeh soltani

    2018-01-01

    Full Text Available Introduction soybean (Glycine max L. plays an important role in three major markets of grains, oil and meal. damage of weeds in soybean generally 13 to 60 and sometimes more than %80 have been reported Farming methods through proper management, sowing date and by use of optimum density could be a strategy for the development of ecological competitiveness of crops and inhibit weed growth are the comparison the growth indices to design interference models of weed and crop and estimate crop yield loss in competition with weed is essential and allow to plant breeding researcher to choice the more competitive varieties of crop in competition with weed. Materials and Methods With the aim of influencing sowing date and plant density on the growth indices and evaluation the competitive ability of soybean cultivar Williams with weeds, an experiment was conducted in 2013, at Agricultural Research Station, Ferdowsi University of Mashhad, as split-split based on a randomized complete block design with three replications. Main plot included three sowing dates levels (17 April, 12 May, 6 June and sub - plots included four crop density (30, 40, 50 and 60 plant . m-2 and sub - sub plots included weed management of two level (weed infested and weedy control. First sampling was started at 35 days after planting and was every 14 days until the end of growth period. Leaf area index, dry matter, crop growth rate and the growth rate were calculated Results and Discussion The results showed that 11 species weed belonging to 9 families observed and identified. In the early stages of growth, leaf area index and dry matter increased slowly, but in the seven to eight leaf stage of plant growth (Log phase, leaf area index and dry matter increased rapidly, and a little upon entry to the plant Physiological maturity period (Early seedling peeks, and again began to decline at the end of seedling. The sowing date 12 May in contrast to early sowing date (17 April and delayed

  19. Isolation of fusarium species from some food and feed and prevention their growth by irradiation

    International Nuclear Information System (INIS)

    Youssef, K.A.; Abouzeid, M.A.; Hassan, A.A.; Abd-Elrahman, D.G.; Hammad, A.A.

    2007-01-01

    Seventy samples of different cereal grains, garlic, onion and animal feed were collected from the Egyptian markets to isolate associated moulds. Fusarium, Aspergillus, Penicillium and Rhizopus were the most common fungal genera isolated from the different samples. The genus Fusarium was the most dominant among the fungal genera and all isolates were identified as F. verticillioides, F. solani, F. oxysporum, F. dimerum, F. tabacinum and F. xylaroides. Fusarium verticillioides and F. solani were the most dominant comprising 58% of the total isolates. All Fusarium isolates were proved to produce one or more of zearalenone, diacetoxyscirpenol and fusaric acids in liquid medium. Irradiation at a dose of 5 KGy reduced the Fusarium growth greatly relative to non-irradiated controls. On the basis of the radiation survival data, the radiation decimal reduction doses (D 10 values) for F. oxysporum, F. solani, F. verticillioides and F. dimerum were 1.44, 1.66, 1.73 and 1.00 KGy in corn, respectively. Application of radiation at a dose of 12.5 KGy made corn samples free from mould throughout all the storage period (12 weeks) and there was no fungal growth and no mycotoxins have been produced

  20. 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...

  1. Developing Inventory Projection Models Using Empirical Net Forest Growth and Growing-Stock Density Relationships Across U.S. Regions and Species Group

    Science.gov (United States)

    Prakash Nepal; Peter J. Ince; Kenneth E. Skog; Sun J. Chang

    2012-01-01

    This paper describes a set of empirical net forest growth models based on forest growing-stock density relationships for three U.S. regions (North, South, and West) and two species groups (softwoods and hardwoods) at the regional aggregate level. The growth models accurately predict historical U.S. timber inventory trends when we incorporate historical timber harvests...

  2. [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.

  3. Potentialities of line planting technique in rehabilitation of logged over area referred to species diversity, growth and soil quality

    Directory of Open Access Journals (Sweden)

    PRIJANTO PAMOENGKAS

    2010-01-01

    Full Text Available Pamoengkas P (2010 Potentialities of line planting technique in rehabilitation of logged over area referred to species diversity, growth and soil quality. Biodiversitas 11: 34-39. Human interventions in the utilization of tropical forest resources are experiencing unanticipated consequences. The selective logging practices generally cause considerable damage to vegetation and the soil surface. It is supposed that soil condition and vegetation growth rate are deteriorated and reduced. Therefore, scientist strongly argue that the only way to achieve sustainability of Indonesian natural forest will require that the production natural forest is managed through methods that are acceptable from the perspective of environment as well as timber production. This means that there will be a strong need and incentive for methods and innovative technology. For more than two decades, tropical rainforest in Indonesia have been managed intensively under the Indonesian selective cutting (TPI and later on by the Indonesian selective cutting and replanting (TPTI and then, selective cutting and line planting (TPTJ system. TPTJ, as one example of selective cutting, recently become a proper alternative should be taken into consideration in the management of production natural forest in Indonesia by planting dipterocarp species in line. In this system, planting line (width 3 m and intermediate line (width 17 m are made alternately. The initial width of line is 3 m and to be expanded until 10 m within 5 years to introduce more light. The objective of this research was to assess growth and soil quality of TPTJ system. The object of research was TPTJ plot of various ages from 1 year to 7 years. For achieving the objective, 14 sample plots measuring 200 m x 200 m each, were laid out at research plots. The result showed that growth respond of Shorea leprosula toward the width of planting line was better comparing to Shorea parvifolia, but generally from this growth

  4. Effects of rooting and tree growth of selected woodland species on cap integrity in a mineral capped landfill site.

    Science.gov (United States)

    Hutchings, T R; Moffat, A J; Kemp, R A

    2001-06-01

    The above and below ground growth of three tree species (Alnus glutinosa, Pinus nigra var. maritima and Acer pseudoplatanus) was studied on a containment landfill site at Waterford, Hertfordshire, UK. Tree root architecture was studied using soil inspection pits excavated next to 12 trees of each species and mapped in detail. Tree height was related to soil thickness over the compacted mineral cap. No roots entered the cap where soil thickness was 1.3 m, but a few roots, especially of alder, were observed within it when the soil cover was 1.0 m or less. Micromorphological analysis of undisturbed samples of the mineral cap suggested that roots exploited weaknesses in the cap rather than actively causing penetration into it. Alder roots were more tolerant of anaerobic conditions within the cap than the other species examined. The results confirm that mineral caps should be covered by 1.5 m of soil or soil-forming material if tree establishment is intended over a restored landfill site, unless protected by other parts of a composite capping system.

  5. Phenethyl isothiocyanate inhibits growth of human chronic myeloid leukemia K562 cells via reactive oxygen species generation and caspases.

    Science.gov (United States)

    Wang, Yating; Wei, Sixi; Wang, Jishi; Fang, Qin; Chai, Qixiang

    2014-07-01

    Phenethyl isothiocyanate (PEITC), a potential cancer chemopreventive constituent of cruciferous vegetables, including watercress, has been reported to inhibit cancer cell growth by arresting the cell cycle and inducing apoptosis in various human cancer cell models. However, the role of PEITC in the inhibition of human chronic myeloid leukemia (CML) K562 cell growth and its underlying mechanisms have yet to be elucidated. In the present study, PEITC was found to induce cell death through the induction of reactive oxygen species (ROS) stress and oxidative damage. Heme oxygenase‑1 (HO‑1), which participates in the development of numerous tumors and the sensitivity of these tumors to chemotherapeutic drugs, plays a protective role by modulating oxidative injury. Therefore, the present study assessed the inhibitory effect of PEITC on K562 cells and whether HO‑1 facilitated cell apoptosis and ROS generation. PEITC was found to suppress cell growth and cause apoptosis by promoting Fas and Fas ligand expression, increasing ROS generation and by the successive release of cytochrome c as well as the activation of caspase‑9 and caspase‑3. PEITC was also combined with the HO‑1 inhibitor zinc protoporphyrin IX and the inducer hemin to assess whether HO‑1 determines cell survival and ROS generation. The results of the present study suggest that PEITC may be a potential anti‑tumor compound for CML therapy, and that HO‑1 has a critical function in PEITC‑induced apoptosis and ROS generation.

  6. Physiological and Growth Responses of Six Turfgrass Species Relative to Salinity Tolerance

    Directory of Open Access Journals (Sweden)

    Md. Kamal Uddin

    2012-01-01

    Full Text Available The demand for salinity-tolerant turfgrasses is increasing due to augmented use of effluent or low-quality water (sea water for turf irrigation and the growing turfgrass industry in coastal areas. Experimental plants, grown in plastic pots filled with a mixture of river sand and KOSASR peat (9 : 1, were irrigated with sea water at different dilutions imparting salinity levels of 0, 8, 16, 24, 32, 40, or 48 dS m-1. Salinity tolerance was evaluated on the basis of leaf firing, shoot and root growth reduction, proline content, and relative water content. Paspalum vaginatum was found to be most salt tolerant followed by Zoysia japonica and Zoysia matrella, while Digitaria didactyla, Cynodon dactylon “Tifdwarf,” and Cynodon dactylon “Satiri” were moderately tolerant. The results indicate the importance of turfgrass varietal selection for saline environments.

  7. Effect of specific industrial gases on the growth of some tree species

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, V G

    1963-01-01

    Variations in the growth increment of annual rings can serve as index of the injuries effect of various industrial gases on plants. For such an objective, young trees are preferable because they are more responsive to changes of surrounding conditions and recover more rapidly after being affected by gas. The older trees react more slowly, take longer to recover, and as a rule eventually dry up. These differences may be related to the prevalence of different kinds of gas resistance (N.P. Krasinskiy, 1950) at definite ages; in the case of old trees the nature of resistant being anatomical, morphological, and physiological (less oxidation of the cell content), whereas in young trees the biological resistance to gases is greater.

  8. Influence of Light, Temperature, and Macronutrients on Growth and Scopolamine Biosynthesis in Duboisia species.

    Science.gov (United States)

    Ullrich, Sophie Friederike; Rothauer, Andreas; Hagels, Hansjörg; Kayser, Oliver

    2017-07-01

    Scopolamine is used in the pharmaceutical industry as a precursor in the organic synthesis of different classes of important active substances and is extracted in large scale from field grown Duboisia plants. Previous research revealed that plant growth as well as production of scopolamine and its derivatives varies strongly depending on abiotic factors. However, only a small amount of systematic research has been done on the influence of environmental conditions on scopolamine and biomass production, so far. In order to extend knowledge in this field, plants of three different genotypes (wild type Duboisia myoporoides and hybrids of D. myoporoides and Duboisia leichhardtii ) were grown in climate chambers under controlled conditions in order to systematically analyse the influence of temperature (20, 24, 28 °C), light (50-300 µmol/m 2  × s, 12, 18, 24 h per day) and macronutrients (nitrogen, calcium, potassium) on growth and scopolamine biosynthesis. The data indicate that light intensity and daily exposure to light have a major impact on scopolamine production and plant development, whereas temperature only shows a minor influence. Nitrogen (N) positively affects biomass production with increasing levels up to 4 mM, but is negatively correlated with scopolamine content. Calcium (Ca) shows a negative influence on scopolamine biosynthesis at increased levels above 1 mM as well. Potassium (K) neither affects biomass nor scopolamine production within the tested concentration range (0.05-4 mM). All in all, it can be concluded that light intensity and nitrogen supply are especially important regulating variables that can be applied in a targeted manner for influencing scopolamine and biomass production. Georg Thieme Verlag KG Stuttgart · New York.

  9. 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.

  10. Involvement of reactive oxygen species in endosperm cap weakening and embryo elongation growth during lettuce seed germination

    Science.gov (United States)

    Zhang, Yu; Chen, Bingxian; Xu, Zhenjiang; Shi, Zhaowan; Chen, Shanli; Huang, Xi; Chen, Jianxun; Wang, Xiaofeng

    2014-01-01

    Endosperm cap (CAP) weakening and embryo elongation growth are prerequisites for the completion of lettuce seed germination. Although it has been proposed that the cell wall loosening underlying these processes results from an enzymatic mechanism, it is still unclear which enzymes are involved. Here it is shown that reactive oxygen species (ROS), which are non-enzymatic factors, may be involved in the two processes. In Guasihong lettuce seeds imbibed in water, O2·– and H2O2 accumulated and peroxidase activity increased in the CAP, whereas its puncture force decreased. In addition, in the radicle, the increase in embryo growth potential was accompanied by accumulation of O2·– and an increase in peroxidase activity. Imbibing seeds in 0.3% sodium dichloroisocyanurate (SDIC) reduced endosperm viability and the levels of O2·–, H2O2, and peroxidase activity in the CAP, whereas the decrease in its puncture force was inhibited. However, in the embryo, SDIC did not affect the accumulation of O2·–, peroxidase activity, and the embryo growth potential. As a result, SDIC caused atypical germination, in which the endosperm ruptured at the boundary between the CAP and lateral endosperm. ROS scavengers and ROS generation inhibitors inhibited the CAP weakening and also decreased the embryo growth potential, thus decreasing the percentage of seed germination. Exogenous ROS and ROS generation inducers increased the percentage of CAP rupture to some extent, and the addition of H2O2 to 0.3% SDIC enabled some seeds to undergo typical germination. PMID:24744430

  11. 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.

  12. 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

    segment with that of the human, the rat and the mouse EGF precursors, in order to identify highly conserved domains. The examined part of the precursor contains EGF itself and six so-called EGF-like modules. The overall amino acid identity among the four species is 64%. However, the amino acid identity...... differed from around 30% in some segments to around 70% in others. The highest amino acid identity, 71%, was observed for a 345-aa segment that contains three EGF-like modules and which is homologous to a part of the low-density lipoprotein receptor (LDL receptor). The amino acid identities are 64% for EGF...... itself, and 50-67% for the remaining three EGF-like modules. The segment of the LDL receptor that is homologous to a part of the EGF precursor is important for the function of the LDL receptor, and EGF-like modules seem to be involved in protein-protein interactions in a number of proteins. In conclusion...

  13. Initial effects of quinclorac on the survival and growth of high biomass tree species

    Directory of Open Access Journals (Sweden)

    Joshua P. Adams

    2017-07-01

    Full Text Available Increasingly, short rotation woody crops are being planted for biofuel/biomass production on unused lands or marginal agricultural lands. Many of these plantations occur near agriculture land which is intensively managed including yearly herbicide applications. Herbicide drift from these applications may cause tree stress and decreasing yields impacting potential biomass production. Quinclorac, a rice herbicide, is often cited as a potential source of tree damage and is the focal herbicide of this study. Five planting stocks, including three eastern cottonwood clones, a hybrid poplar clone, and American sycamore, were assessed for herbicide affects and deployed at three sites across south Arkansas. Stocks were exposed to a full rate labeled for rice (3.175 L ha-1, two rates simulating drift (1/100th and 1/10th the full rate, and a no-spray control. Survival of all Populus clones decreased drastically as quinclorac rate increased, while there was little observed effect on American sycamore. Some variability in treatment response among poplars occurred below the full herbicide rate; however, direct spraying a full herbicide rate on poplars resulted in survival rates below 65 percent and negative growth rates due to dieback. Conversely, photosynthetic rates of remaining leaves increased as quinclorac rate increased. Survival and damage scores of American sycamore, regardless of herbicide rate, remained nearly constant.

  14. Removal of nutrient limitations in forest gaps enhances growth rate and resistance to cavitation in subtropical canopy tree species differing in shade tolerance.

    Science.gov (United States)

    Villagra, Mariana; Campanello, Paula I; Montti, Lia; Goldstein, Guillermo

    2013-03-01

    A 4-year fertilization experiment with nitrogen (N) and phosphorus (P) was carried out in natural gaps of a subtropical forest in northeastern Argentina. Saplings of six dominant canopy species differing in shade tolerance were grown in five control and five N + P fertilized gaps. Hydraulic architectural traits such as wood density, the leaf area to sapwood area ratio (LA : SA), vulnerability to cavitation (P50) and specific and leaf-specific hydraulic conductivity were measured, as well as the relative growth rate, specific leaf area (SLA) and percentage of leaf damage by insect herbivores. Plant growth rates and resistance to drought-induced embolisms increased when nutrient limitations were removed. On average, the P50 of control plants was -1.1 MPa, while the P50 of fertilized plants was -1.6 MPa. Wood density and LA : SA decreased with N + P additions. A trade-off between vulnerability to cavitation and efficiency of water transport was not observed. The relative growth rate was positively related to the total leaf surface area per plant and negatively related to LA : SA, while P50 was positively related to SLA across species and treatments. Plants with higher growth rates and higher total leaf area in fertilized plots were able to avoid hydraulic dysfunction by becoming less vulnerable to cavitation (more negative P50). Two high-light-requiring species exhibited relatively low growth rates due to heavy herbivore damage. Contrary to expectations, shade-tolerant plants with relatively high resistance to hydraulic dysfunction and reduced herbivory damage were able to grow faster. These results suggest that during the initial phase of sapling establishment in gaps, species that were less vulnerable to cavitation and exhibited reduced herbivory damage had faster realized growth rates than less shade-tolerant species with higher potential growth rates. Finally, functional relationships between hydraulic traits and growth rate across species and treatments

  15. All three quinone species play distinct roles in ensuring optimal growth under aerobic and fermentative conditions in E. coli K12

    Science.gov (United States)

    Nitzschke, Annika

    2018-01-01

    The electron transport chain of E. coli contains three different quinone species, ubiquinone (UQ), menaquinone (MK) and demethylmenaquinone (DMK). The content and ratio of the different quinone species vary depending on the external conditions. To study the function of the different quinone species in more detail, strains with deletions preventing UQ synthesis, as well as MK and/or DMK synthesis were cultured under aerobic and anaerobic conditions. The strains were characterized with respect to growth and product synthesis. As quinones are also involved in the control of ArcB/A activity, we analyzed the phosphorylation state of the response regulator as well as the expression of selected genes.The data show reduced aerobic growth coupled to lactate production in the mutants defective in ubiquinone synthesis. This confirms the current assumption that ubiquinone is the main quinone under aerobic growth conditions. In the UQ mutant strains the amount of MK and DMK is significantly elevated. The strain synthesizing only DMK is less affected in growth than the strain synthesizing MK as well as DMK. An inhibitory effect of MK on aerobic growth due to increased oxidative stress is postulated.Under fermentative growth conditions the mutant synthesizing only UQ is severely impaired in growth. Obviously, UQ is not able to replace MK and DMK during anaerobic growth. Mutations affecting quinone synthesis have an impact on ArcA phosphorylation only under anaerobic conditions. ArcA phosphorylation is reduced in strains synthesizing only MK or MK plus DMK. PMID:29614086

  16. 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

  17. 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.

  18. 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.

  19. Comparing grey water versus tap water and coal ash versus perlite on growth of two plant species on green roofs.

    Science.gov (United States)

    Agra, Har'el; Solodar, Ariel; Bawab, Omar; Levy, Shay; Kadas, Gyongyver J; Blaustein, Leon; Greenbaum, Noam

    2018-08-15

    Green roofs provide important ecosystem services in urban areas. In Mediterranean and other semi-arid climate regions, most perennial plants on green roofs need to be irrigated during the dry season. However, the use of freshwater in such regions is scarce. Therefore, the possibility of using grey water should be examined. Coal ash, produced primarily from the burning of coal in power plants, constitutes an environmental contaminant that should be disposed. One option is to use ash as a growing substrate for plants. Here, we compare the effects of irrigating with grey- versus tap-water and using ash versus perlite as growing substrates in green roofs. The study was conducted in northern Israel in a Mediterranean climate. The design was full factorial with three factors: water-type (grey or tap-water)×substrate-type (coal ash vs perlite)×plant species (Phyla nodiflora, Convolvulus mauritanicus or no-plant). The development of plants and the quality of drainage water along the season, as well as quality of the used substrates were monitored. Both plant species developed well under all the experimental conditions with no effect of water type or substrate type. Under all treatments, both plant species enhanced electrical conductivity (EC) and chemical oxygen demand (COD) of the drainage water. In the summer, EC and COD reached levels that are unacceptable in water and are intended to be reused for irrigation. We conclude that irrigating with grey water and using coal ash as a growth substrate can both be implemented in green roofs. The drainage from tap water as well as from grey water can be further used for irrigating the roof, but for that, COD and EC levels must be lowered by adding a sufficient amount of tap water before reusing. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Neglected grass species of Southern Africa: Nutritive value of conserved Hyperthelia dissoluta harvested at different growth stages

    Directory of Open Access Journals (Sweden)

    Jacob Gusha

    2016-09-01

    Full Text Available Native species like Hyperthelia dissoluta have great potential in livestock production but not much has been done to improve their contribution to that sector.  This study examined 2 conservation methods (drying and ensiling and 3 different growth stages, namely: elongation stage (January, early flowering (February and late flowering stage (March of H. dissoluta in terms of nutritional composition and digestibility.  The method of conservation had a significant effect (P<0.05 on nutritive value, with silage having more P and CP than hay.  Stage of growth had an effect (P<0.05 on all nutritional properties of both hay and silage:  Phosphorus, Ca and CP concentrations and digestibility of hay and silage decreased with maturity, while NDF and ADF concentrations increased.  Silage pH value was significantly higher at elongation (5.2 and late flowering growth stages (5.7 than at early flowering (4.4.  Dry matter digestibility of the conserved material reached levels as high as 82% for silage made at the elongation stage with all values at least 60%.  We conclude that H. dissoluta can be conserved as both silage and hay to produce a good quality feed.  Harvesting at the early flowering stage would seem to provide a good compromise between quantity (not measured in this study and quality of harvested forage.  Further studies seem warranted to determine the acceptability and intake of the material by livestock, the advantages of adding fermentable carbohydrates during ensiling and DM yields in different areas and a range of seasonal conditions. Keywords: Air drying, hay, perennial native grasses, plastic bag silo, quality silage.DOI: 10.17138/TGFT(4179-184

  1. 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

  2. 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

  3. 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.

  4. Seasonal growth, development and morphology of two species of padina adanson: padina tetrastromatica and padina pavonica from the manora coast, Karachi, Pakistan

    International Nuclear Information System (INIS)

    Uddin, W.; Begum, M.; Siddiqui, M. F.

    2015-01-01

    The study was an attempt to investigate some biological aspects dealing with seasonal growth and developmental morphology of two dominant species of brown algae Padina Adanson (Pheaophycota, Dictyotales). Manora Island near Karachi was selected as the area for collection of plants known to have very rich algal flora and Padina is one of the prominent and dominant algae at Manora and found to grow on all types of habitats and on each tide level. It is a perennial alga and shows its presence throughout the year. In order to investigate the seasonal growth and developmental morphology, changes in the plant length, breath, presence of vegetative or reproductive plants, percentage maturity of thallus during the different seasons of a year was observed of the two most common species of genus Padina namely P. tetrastromatica Hauck and P. pavonica (L.) Thivy. The peak season for growth and reproduction is winter, whereas plants found in summer were in small size and mostly in the form of juvenile or early mature stage. There was a slight difference in thallus size and reproductive structures (tetrasporophytes or gametophytes) among the two species and between different areas of the shore, but the pattern of growth and reproduction is same. Environmental factors (Mean air temperature and sea water temperature) show significant negative correlation that influence on the growth and development of Padina species. (author)

  5. Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth.

    Science.gov (United States)

    Kotowska, Martyna M; Hertel, Dietrich; Rajab, Yasmin Abou; Barus, Henry; Schuldt, Bernhard

    2015-01-01

    For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing toward the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density (WD). We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia); three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density, and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, WD showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and WD. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation mechanisms to environment.

  6. Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth

    Directory of Open Access Journals (Sweden)

    Martyna Malgorzata Kotowska

    2015-03-01

    Full Text Available For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing towards the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density. We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia; three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, wood density showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and wood density. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation

  7. Adaptability to climate change in forestry species: drought effects on growth and wood anatomy of ponderosa pines growing at different competition levels

    OpenAIRE

    Fernández, M.E.; Gyenge, J.E.; de Urquiza, M.M.; Varela, S.

    2012-01-01

    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 un...

  8. The Good, the Bad and the Plenty: Interactive Effects of Food Quality and Quantity on the Growth of Different Daphnia Species

    OpenAIRE

    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...

  9. 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.

  10. 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

  11. Growth overcompensation against O3 exposure in two Japanese oak species, Quercus mongolica var. crispula and Quercus serrata, grown under elevated CO2

    International Nuclear Information System (INIS)

    Kitao, Mitsutoshi; Komatsu, Masabumi; Yazaki, Kenichi; Kitaoka, Satoshi; Tobita, Hiroyuki

    2015-01-01

    To assess the effects of elevated concentrations of carbon dioxide (CO 2 ) and ozone (O 3 ) on the growth of two mid-successional oak species native to East Asia, Quercus mongolica var. crispula and Quercus serrata, we measured gas exchange and biomass allocation in seedlings (initially 1-year-old) grown under combinations of elevated CO 2 (550 μmol mol −1 ) and O 3 (twice-ambient) for two growing seasons in an open-field experiment in which root growth was not limited. Both the oak species showed a significant growth enhancement under the combination of elevated CO 2 and O 3 (indicated by total dry mass; over twice of ambient-grown plants, p < .05), which probably resulted from a preferable biomass partitioning into leaves induced by O 3 and a predominant enhancement of photosynthesis under elevated CO 2 . Such an over-compensative response in the two Japanese oak species resulted in greater plant growth under the combination of elevated CO 2 and O 3 than elevated CO 2 alone. - Highlights: • Quercus mongolica var. crispula and Quercus serrata were grown under elevated CO 2 and O 3 . • O 3 induced a preferable biomass allocation into leaves. • Photosynthesis was predominantly enhanced under elevated CO 2 exceeding O 3 impacts. • Combination of elevated CO 2 and O 3 enhanced the growth of two oak species. - O 3 -induced carbon allocation into leaves and CO 2 -enhanced photosynthesis result in a significant growth enhancement in Japanese oak species under the combination of gases.

  12. 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

  13. 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

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

    Science.gov (United States)

    Brotons, Lluís

    2014-01-01

    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.

  15. 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.

  16. Abnormal growth kinetics of h-BN epitaxial monolayer on Ru(0001) enhanced by subsurface Ar species

    Science.gov (United States)

    Wei, Wei; Meng, Jie; Meng, Caixia; Ning, Yanxiao; Li, Qunxiang; Fu, Qiang; Bao, Xinhe

    2018-04-01

    Growth kinetics of epitaxial films often follows the diffusion-limited aggregation mechanism, which shows a "fractal-to-compact" morphological transition with increasing growth temperature or decreasing deposition flux. Here, we observe an abnormal "compact-to-fractal" morphological transition with increasing growth temperature for hexagonal boron nitride growth on the Ru(0001) surface. The unusual growth process can be explained by a reaction-limited aggregation (RLA) mechanism. Moreover, introduction of the subsurface Ar atoms has enhanced this RLA growth behavior by decreasing both reaction and diffusion barriers. Our work may shed light on the epitaxial growth of two-dimensional atomic crystals and help to control their morphology.

  17. 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)

  18. Damage by the Sitka spruce weevil (Pissodes strobi) and growth patterns for 10 spruce species and hybrids over 26 years in the Pacific Northwest.

    Science.gov (United States)

    Russel G. Mitchell; Kenneth H. Wright; Norman E. Johnson

    1990-01-01

    Ten species and hybrids of spruce (Picea spp.) were planted and observed annually for 26 years at three coastal locations in Oregon and Washington to evaluate growth rates and susceptibility to the Sitka spruce weevil (= white pine weevil), Pissodes strobi The 10 spruce were: Sitka spruce, Norway spruce, Lutz spruce, black...

  19. Dietary nutrient composition affects digestible energy utilisation for growth: a study on Nile tilapia (Oreochromis niloticus) and a literature comparison across fish species

    NARCIS (Netherlands)

    Schrama, J.W.; Subramanian, S.; Geurden, I.; Heinsbroek, L.T.N.; Kaushik, S.J.; Verreth, J.A.J.

    2012-01-01

    The effect of the type of non-protein energy (NPE) on energy utilisation in Nile tilapia was studied, focusing on digestible energy utilisation for growth (kgDE). Furthermore, literature data on kgDE across fish species were analysed in order to evaluate the effect of dietary macronutrient

  20. Diameter Growth of Juvenile Trees after Gap Formation in a Bolivian Rain Forest: Responses are Strongly Species-specific and Size-dependent.

    NARCIS (Netherlands)

    Soliz-Gamboa, C.C.; Sandbrink, A.; Zuidema, P.A.

    2012-01-01

    We evaluated growth responses to gap formation for juvenile individuals of three canopy rain forest species: Peltogyne cf. heterophylla, Clarisia racemosa and Cedrelinga catenaeformis. Gaps were formed during selective logging operations 7 yr before sampling in a Bolivian rain forest. We collected

  1. [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%.

  2. 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...... gradient with average annual temperatures (8.2–15.6 °C) and precipitation (511–1427 mm). Methods 'Bud break' was monitored in eight shrub and grass species in six European sites under control and experimentally warmer conditions generated by automatic roofs covering vegetation during the night. Results...... treatments, the responses at each site were species specific and year dependent. Under experimental warming 25% of cases exhibited a significantly earlier onset of the growing season and 10% had a significantly delayed onset of vegetative growth. No geographical gradient was detected in the experimental...

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

    Science.gov (United States)

    Nie, Yunpeng; Chen, Hongsong; Ding, Yali; Yang, Jing; Wang, Kelin

    2017-01-01

    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 δ 13 C 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-growing, D

  4. 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

  5. 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.

  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. 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...

  8. 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

  9. 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.

  10. Relating leaf photosynthetic rate to whole-plant growth: drought and shade effects on seedlings of four Quercus species

    NARCIS (Netherlands)

    Quero Perez, J.L.; Villar, R.; Marañón, T.; Zamora, R.; Vega, D.; Sack, L.

    2008-01-01

    Understanding the impacts of combined resource supplies on seedlings is critical to enable prediction of establishment growth, and forest dynamics. We investigated the effects of irradiance and water treatments on absolute growth, and relative growth rate (RGR) and its components, for seedlings of

  11. 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

  12. Growth overcompensation against O3 exposure in two Japanese oak species, Quercus mongolica var. crispula and Quercus serrata, grown under elevated CO2.

    Science.gov (United States)

    Kitao, Mitsutoshi; Komatsu, Masabumi; Yazaki, Kenichi; Kitaoka, Satoshi; Tobita, Hiroyuki

    2015-11-01

    To assess the effects of elevated concentrations of carbon dioxide (CO2) and ozone (O3) on the growth of two mid-successional oak species native to East Asia, Quercus mongolica var. crispula and Quercus serrata, we measured gas exchange and biomass allocation in seedlings (initially 1-year-old) grown under combinations of elevated CO2 (550 μmol mol(-1)) and O3 (twice-ambient) for two growing seasons in an open-field experiment in which root growth was not limited. Both the oak species showed a significant growth enhancement under the combination of elevated CO2 and O3 (indicated by total dry mass; over twice of ambient-grown plants, p CO2. Such an over-compensative response in the two Japanese oak species resulted in greater plant growth under the combination of elevated CO2 and O3 than elevated CO2 alone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 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.

  14. 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

  15. Changes in climate-growth relationships and IADF formation over time of pine species (Pinus halepensis, P. pinaster and P. sylvestris in Mediterranean environments

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    Jorge Olivar

    2015-04-01

    Full Text Available Background: The Mediterranean basin has experienced an increase in the mean annual temperature, a decrease in the mean annual precipitation, and an increase in the frequency of severe drought periods during the second half of the 20th century. However, winter and spring precipitation has increased and summer precipitation has decreased in the western Mediterranean region. Aim of the study: The objectives of the present study were: i to compare changes in climate-growth relationships over time for Pinus halepensis, P. pinaster and P. sylvestris in Spain ii to quantify the presence of intra-annual density fluctuations (IADFs on the three species, and iii to define the associated climatic variables. Area of study: 26 sampling sites (8 P. halepensis sites, 8 P. pinaster sites and 10 P. sylvestris sites were selected in their distribution area in Spain. Main results: Precipitation is the main factor influencing growth and IADF occurrence in the three species. Wet periods during previous winter and spring induced higher growth rates on P. halepensis and P. pinaster, while P. sylvestris was mostly influenced by summer precipitation. However, the influence of these climatic variables on the growth of these species changed over the studied period. The increase of winter and spring precipitation combined with increasingly harsh summer climatic conditions in the second half of the 20th century may have enhanced the importance of precipitation at the beginning of the growing season on the growth of species subject to higher summer drought stress (P. halepensis and P. pinaster and increased IADF occurrence. Research highlights: Besides reflecting changes in the environmental conditions during the growing season, the inclusion of IADF detection in chronologies adds new information to ring-width chronologies, thereby improving its quality.

  16. Size-dependence of tree growth response to drought for Norway spruce and European beech individuals in monospecific and mixed-species stands.

    Science.gov (United States)

    Ding, H; Pretzsch, H; Schütze, G; Rötzer, T

    2017-09-01

    Climate anomalies have resulted in changing forest productivity, increasing tree mortality in Central and Southern Europe. This has resulted in more severe and frequent ecological disturbances to forest stands. This study analysed the size-dependence of growth response to drought years based on 384 tree individuals of Norway spruce [Picea abies (L.) Karst.] and European beech [Fagus sylvatica ([L.)] in Bavaria, Germany. Samples were collected in both monospecific and mixed-species stands. To quantify the growth response to drought stress, indices for basal area increment, resistance, recovery and resilience were calculated from tree ring measurements of increment cores. Linear mixed models were developed to estimate the influence of drought periods. The results show that ageing-related growth decline is significant in drought years. Drought resilience and resistance decrease significantly with growth size among Norway spruce individuals. Evidence is also provided for robustness in the resilience capacity of European beech during drought stress. Spruce benefits from species mixing with deciduous beech, with over-yielding spruce in pure stands. The importance of the influence of size-dependence within tree growth studies during disturbances is highlighted and should be considered in future studies of disturbances, including drought. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. Topography- and Species-Dependent Climatic Responses in Radial Growth of Picea meyeri and Larix principis-rupprechtii in the Luyashan Mountains of North-Central China

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    Wentao Zhang

    2015-01-01

    Full Text Available Dendroecological techniques were used to examine the relationships between topographic aspects, climate factors and radial growth of Picea meyeri and Larix principis-rupprechtii in Luyashan Mountains, North-Central China. Four sites were selected at timberline and totally 67 trees and 134 cores were collected. Pearson correlation and regression surface analysis were conducted to reveal the growth-climate relationships. The results indicated that the two species both showed significant negative correlations with temperature during preceding November on the two topographic aspects. On both slope aspects, growth of P. meyeri exhibited significant negative correlations with precipitation in current June, whereas growth of L. principis-rupprechtii showed significant negative correlations with precipitation in preceding September. On north-facing slope, tree growth was limited by low temperature in early growing season, which not shown on south-facing slope. If climate warming continues, L. principis-rupprechtii may be more favored and a reverse between relationships with temperature and precipitation maybe occur in growth of trees. Treeline position on the north-facing slope may possess a greater potential for elevation shifting than the south-facing slope. Our results supply useful information for discussing the potential effect of future climate on the forest growth in North-Central China.

  18. 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.

  19. 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.

  20. Effects of the arbuscular mycorrhizal fungus Glomus mosseae on growth and metal uptake by four plant species in copper mine tailings

    International Nuclear Information System (INIS)

    Chen, B.D.; Zhu, Y.-G.; Duan, J.; Xiao, X.Y.; Smith, S.E.

    2007-01-01

    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

  1. Bacillus species (BT42) isolated from Coffea arabica L. rhizosphere antagonizes Colletotrichum gloeosporioides and Fusarium oxysporum and also exhibits multiple plant growth promoting activity.

    Science.gov (United States)

    Kejela, Tekalign; Thakkar, Vasudev R; Thakor, Parth

    2016-11-18

    Colletotrichum and Fusarium species are among pathogenic fungi widely affecting Coffea arabica L., resulting in major yield loss. In the present study, we aimed to isolate bacteria from root rhizosphere of the same plant that is capable of antagonizing Colletotrichum gloeosporioides and Fusarium oxysporum as well as promotes plant growth. A total of 42 Bacillus species were isolated, one of the isolates named BT42 showed maximum radial mycelial growth inhibition against Colletotrichum gloeosporioides (78%) and Fusarium oxysporum (86%). BT42 increased germination of Coffee arabica L. seeds by 38.89%, decreased disease incidence due to infection of Colletotrichum gloeosporioides to 2.77% and due to infection of Fusarium oxysporum to 0 (p Fusarium oxysporum. The mechanism of action of inhibition of the pathogenic fungi found to be synergistic effects of secondary metabolites, lytic enzymes, and siderophores. The major inhibitory secondary metabolite identified as harmine (β-carboline alkaloids).

  2. Restoration of Degraded Soil in the Nanmangalam Reserve Forest with Native Tree Species: Effect of Indigenous Plant Growth-Promoting Bacteria.

    Science.gov (United States)

    Ramachandran, Andimuthu; Radhapriya, Parthasarathy

    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.

  3. 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.

  4. 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.

  5. Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

    International Nuclear Information System (INIS)

    Ribas, Angela; Pen-tilde uelas, Josep; Elvira, Susana; Gimeno, Benjamin S.

    2005-01-01

    Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O 3 ) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb v of O 3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of δ 13 C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in δ 15 N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, δ 15 N, chlorophyll, leaf area, LMA and biomass occurred at ambient O 3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence-related processes and morphological and growth changes in

  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. 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...

  10. Species-specific growth responses to climate variations in understory trees of a Central African rain forest

    NARCIS (Netherlands)

    Couralet, C.; Sterck, F.J.; Sass-Klaassen, U.; Acker, Van J.; Beekman, H.

    2010-01-01

    Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the

  11. Life-history constraints in grassland plant species: a growth-defence trade-off is the norm

    Science.gov (United States)

    E.M. Lind; E.T. Borer; E.W. Seabloom; P.B. Adler; J.D. Bakker; D.M. Blumenthal; M. Crawley; K.F. Davies; J. Firn; D.S. Gruner; S. Harpole; Y. Hautier; H. Hillebrand; J.M.H. Knops; B.A. Melbourne; B. Mortensen; A.C. Risch; M. Schuetz; C.J. Stevens; P.D. Wragg

    2013-01-01

    Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended...

  12. HYPOXIC EFFECT ON GROWTH OF PALEOMENETES VULGARIS LARVAE AND OTHER SPECIES: USING CONSTANT EXPOSURE DATA TO PREDICT CYCLIC EXPOSURE RESPONSE

    Science.gov (United States)

    First stage larval marsh grass shrimp, Palaemonetes vulgaris, were exposed to patterns of diurnal, semidiurnal, and constant hypoxia to evaluate effects on growth and to determine if there was a consistent relationship between exposures. A comparison of growth with cyclic exposur...

  13. 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.

  14. Influence of Species of Vesicular-Arbuscular Mycorrhizal Fungi and Phosphorus Nutrition on Growth, Development, and Mineral Nutrition of Potato (Solanum tuberosum L.).

    Science.gov (United States)

    McArthur, DAJ.; Knowles, N. R.

    1993-07-01

    Growth, development, and mineral physiology of potato (Solanum tuberosum L.) plants in response to infection by three species of vesicular-arbuscular mycorrhizal (VAM) fungi and different levels of P nutrition were characterized. P deficiency in no-P and low-P (0.5 mM) nonmycorrhizal plants developed between 28 and 84 d after planting. By 84 d after planting, P deficiency decreased plant relative growth rate such that no-P and low-P plants had, respectively, 65 and 45% less dry mass and 76 and 55% less total P than plants grown with high P (2.5 mM). A severe reduction in leaf area was also evident, because P deficiency induced a restriction of lateral bud growth and leaf expansion and, also, decreased the relative plant allocation of dry matter to leaf growth. Root growth was less influenced by P deficiency than either leaf or stem growth. Moreover, P-deficient plants accumulated a higher proportion of total available P than high-P plants, indicating that P stress had enhanced root efficiency of P acquisition. Plant P deficiency did not alter the shoot concentration of N, K, Mg, or Fe; however, the total accumulation of these mineral nutrients in shoots of P-stressed plants was substantially less than that of high-P plants. P uptake by roots was enhanced by each of the VAM symbionts by 56 d after planting and at all levels of abiotic P supply. Species differed in their ability to colonize roots and similarly to produce a plant growth response. In this regard, Glomus intraradices (Schenck and Smith) enhanced plant growth the most, whereas Glomus dimorphicum (Boyetchko and Tewari) was least effective, and Glomus mosseae ([Nicol. and Gerd.] Gerd. and Trappe) produced an intermediate growth response. The partial alleviation of P deficiency in no-P and low-P plants by VAM fungi stimulated uptake of N, K, Mg, Fe, and Zn. VAM fungi enhanced shoot concentrations of P, N, and Mg by 28 d after planting and, through a general improvement of overall plant mineral nutrition

  15. 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.

  16. Vaginal lactobacilli inhibiting growth of Gardnerella vaginalis, Mobiluncus and other bacterial species cultured from vaginal content of women with bacterial vaginosis.

    Science.gov (United States)

    Skarin, A; Sylwan, J

    1986-12-01

    On a solid agar medium the growth-inhibitory effect of 9 Lactobacillus strains cultured from vaginal content was tested on bacteria cultured from vaginal content of women with bacterial vaginosis: Mobiluncus, Gardnerella vaginalis, Bacteroides and anaerobic cocci. Inhibition zones were observed in the growth of all of the strains isolated from women with bacterial vaginosis around all lactobacilli. The inhibitory effect of the lactobacilli was further tested on various anaerobic and facultatively anaerobic species, both type strains and fresh extragenitally cultured strains. Four Bacteroides fragilis strains as well as 2 out of 4 Staphylococcus aureus strains were clearly inhibited by the lactobacilli. The inhibition zones were generally wider at pH 5.5 than at 6.0. For all inhibited strains, (the S. aureus excepted) a low pH on the agar around the lactobacilli correlated to wider growth-inhibition zones.

  17. 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.

  18. 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.

  19. 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.

  20. 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

    Directory of Open Access Journals (Sweden)

    Jingjing Yang

    2018-04-01

    Full Text Available 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 (FN, and fresh weight (FW. 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 1,000, making this line the most suitable of the three tested for use in an Hg bioremediation system.

  1. Co-ordination of growth, gas exchange and hydraulics define the carbon safety margin in tree species with contrasting drought strategies.

    Science.gov (United States)

    Mitchell, P J; O'Grady, A P; Tissue, D T; Worledge, D; Pinkard, E A

    2014-05-01

    Gas exchange, growth, water transport and carbon (C) metabolism diminish during drought according to their respective sensitivities to declining water status. The timing of this sequence of declining physiological functions may determine how water and C relations compromise plant survival. In this paper, we test the hypothesis that the degree of asynchrony between declining C supply (photosynthesis) and C demand (growth and respiration) determines the rate and magnitude of changes in whole-plant non-structural carbohydrates (NSC) during drought. Two complementary experiments using two tree species (Eucalyptus globulus Labill. and Pinus radiata D. Don) with contrasting drought response strategies were performed to (i) assess changes in radial stem growth, transpiration, leaf water potential and gas exchange in response to chronic drought, and (ii) evaluate the concomitant impacts of these drought responses on the temporal patterns of NSC during terminal drought. The three distinct phases of water stress were delineated by thresholds of growth cessation and stomatal closure that defined the 'carbon safety margin' (i.e., the difference between leaf water potential when growth is zero and leaf water potential when net photosynthesis is zero). A wider C safety margin in E. globulus was defined by an earlier cessation of growth relative to photosynthesis that reduced the demand for NSC while maintaining C acquisition. By contrast, the narrower C safety margin in P. radiata was characterized by a synchronous decline in growth and photosynthesis, whereby growth continued under a declining supply of NSC from photosynthesis. The narrower C safety margin in P. radiata was associated with declines in starch concentrations after ∼ 90 days of chronic drought and significant depletion of starch in all organs at mortality. The observed divergence in the sensitivity of drought responses is indicative of a potential trade-off between maintaining hydraulic safety and adequate C

  2. 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.

  3. 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.

  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. 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.

  6. 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.

  7. 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

  8. Plant Trait Dataset for Tree-Like Growth Forms Species of the Subtropical Atlantic Rain Forest in Brazil

    Directory of Open Access Journals (Sweden)

    Arthur Vinicius Rodrigues

    2018-05-01

    Full Text Available Plant functional traits have been incorporated in studies of vegetation ecology to better understand the mechanisms of ecological processes. For this reason, a global effort has been made to collect functional traits data for as many species as possible. In light of this, we identified the most common species of an area of 15,335 km2 inserted in the subtropical Atlantic Rain Forest in Southern Brazil. Then, we compiled functional trait information mostly from field samples, but also from herbarium and literature. The dataset presents traits of leaf, branch, maximum potential height, seed mass, and dispersion syndrome of 117 species, including trees, tree ferns, and palms. We also share images of anatomical features of branches used to measure wood traits. Data tables present mean trait values at individual and species level. Images of wood and stomatal features may be useful to assess other anatomical traits that were not covered in the data tables for the anatomical determination of species and/or for educational purposes.

  9. 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.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    2011-04-15

    For several decades, acid rain has been an environmental problem in North America and Europe and is now so in China. The aim of that study was to determine the effects and potential interactions between simulated acid rain (SiAR) and calcium on seed germination of different tree species present in China. Seeds from six tree species were grown is a laboratory where they were spread with SiAR or water as control and where calcium was applied at three levels. Results showed that two species were highly tolerant to SiAR while the others were sensitive; the addition of calcium also had a rescue effect on sensitive seeds but no significant effect on the tolerant ones.

  12. 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.

  13. Pumpkin seed cake as a fishmeal substitute in fish nutrition: effects on growth performance, morphological traits and fillet colour of two freshwater salmonids and two catfish species.

    Science.gov (United States)

    Greiling, Alexander Michael; Schwarz, Christiane; Gierus, Martin; Rodehutscord, Markus

    2018-06-01

    The objectives of this study were to investigate the digestibility of pumpkin seed cake (PSC) for the rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), and effects on performance and product quality traits of four different fish species when PSC partially replaced fishmeal in extruded diets. A digestibility trial was carried out to determine apparent digestibility coefficients (ADC) for crude protein (CP), ether extract (EE) and gross energy (GE) of PSC fed to rainbow trout. In subsequent growth trials, effects on performance and morphological traits and fillet colour values of four different fish species [rainbow trout; brook trout, Salvelinus fontinalis (Mitchill, 1814); African sharptooth catfish, Clarias gariepinus (Burchell, 1822); and wels catfish, Silurus glanis (Linnaeus, 1758)] were evaluated when 60% of fishmeal protein of a reference diet was replaced by PSC protein (based on digestible CP). Nutrient ADC of PSC were high (CP: 89%, EE: 88% and GE: 84%). No significant effects on growth and only minor effects on fillet colour were detected in the trials. However, replacing fishmeal with PSC at the chosen level affected morphological traits and feed conversion in all four species to different extents. Replacement effects of PSC should be tested at lower levels of inclusion before conclusions are drawn on its suitability in fish diets.

  14. 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.

  15. Thermal tolerance, net CO2 exchange and growth of a tropical tree species, Ficus insipida, cultivated at elevated daytime and nighttime temperatures.

    Science.gov (United States)

    Krause, G Heinrich; Cheesman, Alexander W; Winter, Klaus; Krause, Barbara; Virgo, Aurelio

    2013-06-15

    Global warming and associated increases in the frequency and amplitude of extreme weather events, such as heat waves, may adversely affect tropical rainforest plants via significantly increased tissue temperatures. In this study, the response to two temperature regimes was assessed in seedlings of the neotropical pioneer tree species, Ficus insipida. Plants were cultivated in growth chambers at strongly elevated daytime temperature (39°C), combined with either close to natural (22°C) or elevated (32°C) nighttime temperatures. Under both growth regimes, the critical temperature for irreversible leaf damage, determined by changes in chlorophyll a fluorescence, was approximately 51°C. This is comparable to values found in F. insipida growing under natural ambient conditions and indicates a limited potential for heat tolerance acclimation of this tropical forest tree species. Yet, under high nighttime temperature, growth was strongly enhanced, accompanied by increased rates of net photosynthetic CO2 uptake and diminished temperature dependence of leaf-level dark respiration, consistent with thermal acclimation of these key physiological parameters. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. 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)

  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. 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.

  19. 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...

  20. 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.

  1. 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.

  2. SPECIES-SPECIFIC PARTITIONING OF SOIL WATER RESOURCES IN AN OLD-GROWTH DOUGLAS-FIR/WESTERN HEMLOCK FOREST

    Science.gov (United States)

    Although tree- and stand-level estimates of forest water use are increasingly common, relatively little is known about partitioning of soil water resources among co-occurring tree species. We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menzies...

  3. 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...

  4. 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

  5. Links between belowground and aboveground resource-related traits reveal species growth strategies that promote invasive advantages.

    Science.gov (United States)

    Smith, Maria S; Fridley, Jason D; Goebel, Marc; Bauerle, Taryn L

    2014-01-01

    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. 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.

  7. 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

  8. Experimentally manipulated brood sex ratios : Growth and survival in the black-headed gull (Larus ridibundus), a sexually dimorphic species

    NARCIS (Netherlands)

    Mueller, Wendt; Kalmbach, E; Eising, C.M; Groothuis, TGG; Dijkstra, C

    2005-01-01

    In sexually size dimorphic species, individuals of the larger sex often suffer from enhanced mortality during the nestling period. This has been attributed to higher nutritional requirements of the larger sex, which may render this sex more vulnerable to adverse food conditions. However, sex-biased

  9. 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...

  10. 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 . There were distinct family and provenance differences for growth at the different sites, with the Hanging Rock provenance generally performing well across all sites. A genotype × environment interaction was present between two sites, as indicated by low Type...

  11. Soil seed banks and growth rates of an invasive species, Piper aduncum, in the lowlands of Papua New Guinea

    NARCIS (Netherlands)

    Rogers, H.R.; Hartemink, A.E.

    2000-01-01

    Secondary fallow vegetation in parts of the Papua New Guinea lowlands is dominated by the shrub Piper aduncum L. that originates from South America. Here we report on its seed bank, growth rate and biomass accumulation. P. aduncum accounted for 69 % (408 m[minus sign]2) of the seed bank in the

  12. Acclimation of shade-tolerant and light-resistant Tradescantia species to growth light: chlorophyll a fluorescence, electron transport, and xanthophyll content.

    Science.gov (United States)

    Mishanin, Vladimir I; Trubitsin, Boris V; Patsaeva, Svetlana V; Ptushenko, Vasily V; Solovchenko, Alexei E; Tikhonov, Alexander N

    2017-09-01

    In this study, we have compared the photosynthetic characteristics of two contrasting species of Tradescantia plants, T. fluminensis (shade-tolerant species), and T. sillamontana (light-resistant species), grown under the low light (LL, 50-125 µmol photons m -2  s -1 ) or high light (HL, 875-1000 µmol photons m -2  s -1 ) conditions during their entire growth period. For monitoring the functional state of photosynthetic apparatus (PSA), we measured chlorophyll (Chl) a emission fluorescence spectra and kinetics of light-induced changes in the heights of fluorescence peaks at 685 and 740 nm (F 685 and F 740 ). We also compared the light-induced oxidation of P 700 and assayed the composition of carotenoids in Tradescantia leaves grown under the LL and HL conditions. The analyses of slow induction of Chl a fluorescence (SIF) uncovered different traits in the LL- and HL-grown plants of ecologically contrasting Tradescantia species, which may have potential ecophysiological significance with respect to their tolerance to HL stress. The fluorometry and EPR studies of induction events in chloroplasts in situ demonstrated that acclimation of both Tradescantia species to HL conditions promoted faster responses of their PSA as compared to LL-grown plants. Acclimation of both species to HL also caused marked changes in the leaf anatomy and carotenoid composition (an increase in Violaxanthin + Antheraxantin + Zeaxanthin and Lutein pools), suggesting enhanced photoprotective capacity of the carotenoids in the plants grown in nature under high irradiance. Collectively, the results of the present work suggest that the mechanisms of long-term PSA photoprotection in Tradescantia are based predominantly on the light-induced remodeling of pigment-protein complexes in chloroplasts.

  13. Induction of sporulation and the influence of time, temperature, and inoculum size on growth in two species of aquatic fungi (Saprolegniales)

    Science.gov (United States)

    Bailey, T.A.; Bradford, K.; Bland, C.E.

    1990-01-01

    Because the infective stage of most mycoses of aquatic organisms is the zoospore, we attempted to establish optimum conditions under which zoospores could be produced for use in antifungal testing. Optimum sporulation time, incubation time, inoculum size, and growth temperature were determined for each oftwo saprolegniaceous fungi, Achlya flagellata Coker and Saprolegnia hypogyna (Pringsheim) de Bary. Both species produced the largest number of zoospores after 18 hours (51.7 spores/ml for A. jlagellata and 848.0 spores/ml for S. hypogyna), and yielded maximum growth after 48 hours at 22 'C. The recommended test inoculum size for S. hypogyna (5,600 spores/ml was nearly three times that for A. flagellata (2,000 spores/ml),

  14. Approximate probabilistic cellular automata for the dynamics of single-species populations under discrete logisticlike growth with and without weak Allee effects.

    Science.gov (United States)

    Mendonça, J Ricardo G; Gevorgyan, Yeva

    2017-05-01

    We investigate one-dimensional elementary probabilistic cellular automata (PCA) whose dynamics in first-order mean-field approximation yields discrete logisticlike growth models for a single-species unstructured population with nonoverlapping generations. Beginning with a general six-parameter model, we find constraints on the transition probabilities of the PCA that guarantee that the ensuing approximations make sense in terms of population dynamics and classify the valid combinations thereof. Several possible models display a negative cubic term that can be interpreted as a weak Allee factor. We also investigate the conditions under which a one-parameter PCA derived from the more general six-parameter model can generate valid population growth dynamics. Numerical simulations illustrate the behavior of some of the PCA found.

  15. 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.

  16. Stochastic modelling of tree architecture and biomass allocation: application to teak (Tectona grandis L. f.), a tree species with polycyclic growth and leaf neoformation.

    Science.gov (United States)

    Tondjo, Kodjo; Brancheriau, Loïc; Sabatier, Sylvie; Kokutse, Adzo Dzifa; Kokou, Kouami; Jaeger, Marc; de Reffye, Philippe; Fourcaud, Thierry

    2018-06-08

    For a given genotype, the observed variability of tree forms results from the stochasticity of meristem functioning and from changing and heterogeneous environmental factors affecting biomass formation and allocation. In response to climate change, trees adapt their architecture by adjusting growth processes such as pre- and neoformation, as well as polycyclic growth. This is the case for the teak tree. The aim of this work was to adapt the plant model, GreenLab, in order to take into consideration both these processes using existing data on this tree species. This work adopted GreenLab formalism based on source-sink relationships at organ level that drive biomass production and partitioning within the whole plant over time. The stochastic aspect of phytomer production can be modelled by a Bernoulli process. The teak model was designed, parameterized and analysed using the architectural data from 2- to 5-year-old teak trees in open field stands. Growth and development parameters were identified, fitting the observed compound organic series with the theoretical series, using generalized least squares methods. Phytomer distributions of growth units and branching pattern varied depending on their axis category, i.e. their physiological age. These emerging properties were in accordance with the observed growth patterns and biomass allocation dynamics during a growing season marked by a short dry season. Annual growth patterns observed on teak, including shoot pre- and neoformation and polycyclism, were reproduced by the new version of the GreenLab model. However, further updating is discussed in order to ensure better consideration of radial variation in basic specific gravity of wood. Such upgrading of the model will enable teak ideotypes to be defined for improving wood production in terms of both volume and quality.

  17. Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, Angela [CSIC-CEAB-CREAF Ecophysiology Unit, CREAF-Center for Ecological Research and Forestry Applications, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: a.ribas@creaf.uab.es; Pen-tilde uelas, Josep [CSIC-CEAB-CREAF Ecophysiology Unit, CREAF-Center for Ecological Research and Forestry Applications, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: josep.penuelas@uab.es; Elvira, Susana [CIEMAT, Avd. Complutense 22, 28040 Madrid (Spain); Gimeno, Benjamin S. [CIEMAT, Avd. Complutense 22, 28040 Madrid (Spain)

    2005-03-01

    -related processes and morphological and growth changes in seedlings of Mediterranean tree species.

  18. Methylobacterium Species Promoting Rice and Barley Growth and Interaction Specificity Revealed with Whole-Cell Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF/MS Analysis.

    Directory of Open Access Journals (Sweden)

    Akio Tani

    Full Text Available Methylobacterium species frequently inhabit plant surfaces and are able to utilize the methanol emitted from plants as carbon and energy sources. As some of the Methylobacterium species are known to promote plant growth, significant attention has been paid to the mechanism of growth promotion and the specificity of plant-microbe interactions. By screening our Methylobacterium isolate collection for the high growth promotion effect in vitro, we selected some candidates for field and pot growth tests for rice and barley, respectively. We found that inoculation resulted in better ripening of rice seeds, and increased the size of barley grains but not the total yield. In addition, using whole-cell matrix-assister laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS analysis, we identified and classified Methylobacterium isolates from Methylobacterium-inoculated rice plants. The inoculated species could not be recovered from the rice plants, and in some cases, the Methylobacterium community structure was affected by the inoculation, but not with predomination of the inoculated species. The isolates from non-inoculated barley of various cultivars grown in the same field fell into just two species. These results suggest that there is a strong selection pressure at the species level of Methylobacterium residing on a given plant species, and that selection of appropriate species that can persist on the plant is important to achieve growth promotion.

  19. Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2014-01-01

    Full Text Available 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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....

  4. 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

  5. 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.

  6. 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.

  7. Growth and gas production of a novel obligatory heterofermentative Cheddar cheese nonstarter lactobacilli species on ribose and galactose.

    Science.gov (United States)

    Ortakci, Fatih; Broadbent, Jeffery R; Oberg, Craig J; McMahon, Donald J

    2015-06-01

    An obligatory heterofermentative lactic acid bacterium, Lactobacillus wasatchii sp. nov., isolated from gassy Cheddar cheese was studied for growth, gas formation, salt tolerance, and survival against pasteurization treatments at 63°C and 72°C. Initially, Lb. wasatchii was thought to use only ribose as a sugar source and we were interested in whether it could also utilize galactose. We conducted experiments to determine the rate and extent of growth and gas production in carbohydrate-restricted (CR) de Man, Rogosa, and Sharpe (MRS) medium under anaerobic conditions with various combinations of ribose and galactose at 12, 23, and 37°C, with 23°C being the optimum growth temperature of Lb. wasatchii among the 3 temperatures studied. When Lb. wasatchii was grown on ribose (0.1, 0.5, and 1%), maximum specific growth rates (µmax) within each temperature were similar. When galactose was the only sugar, compared with ribose, µmax was 2 to 4 times lower. At all temperatures, the highest final cell densities (optical density at 640 nm) of Lb. wasatchii were achieved in CR-MRS plus 1% ribose, 0.5% ribose and 0.5% galactose, or 1% ribose and 1% galactose. Similar µmax values and final cell densities were achieved when 50% of the ribose in CR-MRS was substituted with galactose. Such enhanced utilization of galactose in the presence of ribose to support bacterial growth has not previously been reported. It appears that Lb. wasatchii co-metabolizes ribose and galactose, utilizing ribose for energy and galactose for other functions such as cell wall biosynthesis. Co-utilization of both sugars could be an adaptation mechanism of Lb. wasatchii to the cheese environment to efficiently ferment available sugars for maximizing metabolism and growth. As expected, gas formation by the heterofermenter was observed only when galactose was present in the medium. Growth experiments with MRS plus 1.5% ribose at pH 5.2 or 6.5 with 0, 1, 2, 3, 4, or 5% NaCl revealed that Lb. wasatchii is

  8. MG132 as a proteasome inhibitor induces cell growth inhibition and cell death in A549 lung cancer cells via influencing reactive oxygen species and GSH level.

    Science.gov (United States)

    Han, Yong Hwan; Park, Woo Hyun

    2010-07-01

    Carbobenzoxy-Leu-Leu-leucinal (MG132) as a proteasome inhibitor has been shown to induce apoptotic cell death through formation of reactive oxygen species (ROS). In the present study, we evaluated the effects of MG132 on the growth of A549 lung cancer cells in relation to cell growth, ROS and glutathione (GSH) levels. Treatment with MG132 inhibited the growth of A549 cells with an IC(50) of approximately 20 microM at 24 hours. DNA flow cytometric analysis indicated that 0.5 approximately 30 microM MG132 induced a G1 phase arrest of the cell cycle in A549 cells. Treatment with 10 or 30 microM MG132 also induced apoptosis, as evidenced by sub-G1 cells and annexin V staining cells. This was accompanied by the loss of mitochondrial membrane potential (MMP; Delta psi m). The intracellular ROS levels including O(2) (*-) were strongly increased in 10 or 30 microM MG132-treated A549 cells but were down-regulated in 0.1, 0.5 or 1 microM MG132-treated cells. Furthermore, 10 or 30 microM MG132 increased mitochondrial O(2) (*- ) level but 0.1, 0.5 or 1 microM MG132 decreased that. In addition, 10 or 30 microM MG132 induced GSH depletion in A549 cells. In conclusion, MG132 inhibited the growth of human A549 cells via inducing the cell cycle arrest as well as triggering apoptosis, which was in part correlated with the changes of ROS and GSH levels. Our present data provide important information on the anti-growth mechanisms of MG132 in A549 lung cancer cells in relation to ROS and GSH.

  9. Growth and photosynthetic responses of two pine species (Pinus koraiensis and Pinus rigida) in a polluted industrial region in Korea

    International Nuclear Information System (INIS)

    Choi, D.S.; Kayama, M.; Jin, H.O.; Lee, C.H.; Izuta, T.; Koike, T.

    2006-01-01

    We investigated the effects of pollutants on two pine species (Pinus koraiensis and Pinus rigida) in an industrial region in Korea, using a physiological approach. The concentrations of fluorine (F) and chlorine (Cl) in the atmosphere, in precipitation and soil water at the damaged site were all significantly higher than at a control site. Moreover, the concentrations of F, Cl and Mn in pine needles were significantly higher, and essential elements and chlorophyll in needles were significantly lower at the damaged site than at the control site. The photosynthetic capacities, shoot length and survival statistics of needles of the two pines were all significantly reduced at the damaged site compared to the control site, especially P. rigida. Based on our comparison of photosynthetic responses and the concentrations of F, Cl and Mn in needles of the two pine species, P. koraiensis is more resistant to excess Mn in its needles than P. rigida. - Pinus koraiensis seems to be more pollution tolerant than Pinus rigida

  10. 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 of these met...... 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......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...

  11. 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.

  12. 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.

  13. 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.

  14. Laboratory evaluation of temperature effects on the germination and growth of entomopathogenic fungi and on their pathogenicity to two aphid species.

    Science.gov (United States)

    Yeo, Helen; Pell, Judith K; Alderson, Peter G; Clark, Suzanne J; Pye, Barry J

    2003-02-01

    As part of an approach to select potential mycoinsecticides for aphid biocontrol, we investigated the effects of temperature on the growth, germination and pathogenicity of some hyphomycete fungi. Commercially available mycoinsecticides (based on Beauveria bassiana (Balsamo) Vuillemin and Verticillium lecanii (Zimmermann) Viegas) and other isolates of B bassiana, V lecanii, Metarhizium anisopliae (Metschnikoff) Sorokin and Paecilomyces fumosoroseus (Wize) Brown & Smith were evaluated. The rate of in vitro conidial germination of all isolates was slower at 10 and 15 degrees C than at 20 and 25 degrees C. Similarly, in vitro growth of most isolates was adversely affected at 10 and 15 degrees C. The greatest reduction at 10 degrees C in rates of conidial germination and colony growth, compared with other temperatures, was for M anisopliae isolates. Germination of V lecanii (isolate HRI 1.72) was fastest at 10 degrees C compared with the other fungi. It was also the most pathogenic of three isolates tested against Aphis fabae Scopoli and Myzus persicae Sulzer at 10, 18 and 23 degrees C. Generally, A fabae was more susceptible than M persicae to infection by the fungal isolates tested. A significant interaction between aphid species and temperature indicated that the pathogenic nature of an isolate was dependent not only on the target aphid species but also the temperature conditions of the bioassay. The series of studies, detailed above, allowed a temperature profile to be formed for the different isolates. Verticillium lecanii isolate HRI 1.72 (commercialised as Vertalec) was the most promising isolate selected from results of the series of experiments. Temperature profiles in conjunction with infectivity assays can be useful in selecting appropriate isolates for a particular thermal environment.

  15. Growth performance and feed conversion efficiency of three edible mealworm species (Coleoptera: Tenebrionidae) on diets composed of organic by-products.

    Science.gov (United States)

    van Broekhoven, Sarah; Oonincx, Dennis G A B; van Huis, Arnold; van Loon, Joop J A

    2015-02-01

    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. Three edible mealworm species Tenebrio molitor L., Zophobas atratus Fab. and Alphitobius diaperinus Panzer were grown on diets composed of organic by-products originating from beer brewing, bread/cookie baking, potato processing and bioethanol production. Experimental diets differed with respect to protein and starch content. Larval growth and survival was monitored. Moreover, effects of dietary composition on feed conversion efficiency and mealworm crude protein and fatty acid profile were assessed. Diet affected mealworm development and feed conversion efficiency such that diets high in yeast-derived protein appear favourable, compared to diets used by commercial breeders, with respect to shortening larval development time, reducing mortality and increasing weight gain. Diet also affected the chemical composition of mealworms. Larval protein content was stable on diets that differed 2-3-fold in protein content, whereas dietary fat did have an effect on larval fat content and fatty acid profile. However, larval fatty acid profile did not necessarily follow the same trend as dietary fatty acid composition. Diets that allowed for fast larval growth and low mortality in this study led to a comparable or less favourable n6/n3 fatty acid ratio compared to control diets used by commercial breeders. In conclusion, the mealworm species used in this study can be grown successfully on diets composed of organic by-products. Diet composition did not influence larval protein content, but did alter larval fat composition to a certain extent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 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

  17. 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 .

  18. 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.

  19. 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

  20. Algal growth and species composition under experimental control of herbivory, phosphorus and coral abundance in Glovers Reef, Belize.

    Science.gov (United States)

    McClanahan, T R; Cokos, B A; Sala, E

    2002-06-01

    The proliferation of algae on disturbed coral reefs has often been attributed to (1) a loss of large-bodied herbivorous fishes, (2) increases in sea water nutrient concentrations, particularly phosphorus, and (3) a loss of hard coral cover or a combination of these and other factors. We performed replicated small-scale caging experiments in the offshore lagoon of Glovers Reef atoll, Belize where three treatments had closed-top (no large-bodied herbivores) and one treatment had open-top cages (grazing by large-bodied herbivores). Closed-top treatments simulated a reduced-herbivory situation, excluding large fishes but including small herbivorous fishes such as damselfishes and small parrotfishes. Treatments in the closed-top cages included the addition of high phosphorus fertilizer, live branches of Acropora cervicornis and a third unmanipulated control treatment. Colonization, algal biomass and species composition on dead A. palmata "plates" were studied weekly for 50 days in each of the four treatments. Fertilization doubled the concentration of phosphorus from 0.35 to 0.77 microM. Closed-top cages, particularly the fertilizer and A. cervicornis additions, attracted more small-bodied parrotfish and damselfish than the open-top cages such that there was moderate levels of herbivory in closed-top cages. The open-top cages did, however, have a higher abundance of the chemically and morphologically defended erect algal species including Caulerpa cupressoides, Laurencia obtusa, Dictyota menstrualis and Lobophora variegata. The most herbivore-resistant calcareous green algae (i.e. Halimeda) were, however, uncommon in all treatments. Algal biomass increased and fluctuated simultaneously in all treatments over time, but algal biomass, as measured by wet, dry and decalcified weight, did not differ greatly between the treatments with only marginally higher biomass (p reefs except for creating space. In contrast, A. cervicornis appears to attract aggressive damselfish that

  1. Kinetic Behaviors of Catalysis-Driven Growth of Three-Species Aggregates on Base of Exchange-Driven Aggregations

    International Nuclear Information System (INIS)

    Sun Yunfei; Chen Dan; Lin Zhenquan; Ke Jianhong

    2009-01-01

    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 K 1 (k, j) = K 1 kj and K 2 (k, j) = K 2 kj, 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 J 1 (k, j) = J 1 k and J 2 (k, j) = J 2 k, respectively. Meanwhile, the asset and resource aggregates conjunctly catalyze the monomer birth of population aggregates with the rate kernel I 1 (k, i, j) = I 1 ki μ j η , and population and resource aggregates conjunctly catalyze the monomer birth of asset aggregates with the rate kernel I 2 (k, i, j) = I 2 ki v j η . 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 J 1e = J 1 /K 1 and J 2e = J 2 /K 2 , 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 J 1e 2e , J 1e = J 2e , and J 1e > J 2e , 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

  2. 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

  3. 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.

  4. 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

  5. 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...

  6. A New Class of Quorum Quenching Molecules from Staphylococcus Species Affects Communication and Growth of Gram-Negative Bacteria

    Science.gov (United States)

    Chu, Ya-Yun; Nega, Mulugeta; Wölfle, Martina; Plener, Laure; Grond, Stephanie; Jung, Kirsten; Götz, Friedrich

    2013-01-01

    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-yl)ethyl]-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. PMID:24098134

  7. Physiological and growth responses of two African species, Acacia karroo and Themeda triandra, to combined increases in CO2 and UV-B radiation

    International Nuclear Information System (INIS)

    Wand, S.J.E.; Midgley, G.F.; Musil, C.F.

    1996-01-01

    The interactive effects of increased carbon dioxide (CO 2 ) concentration and ultraviolet-B (UV-B, 280–320 nm) radiation on Acacia karroo Hayne, a C 3 tree, and Themeda triandra Forsk., a C 4 grass, were investigated. We tested the hypothesis that A. karroo would show greater CO 2 -induced growth stimulation than T. triandra, which would partially explain current encroachment of A. karroo into C4 grasslands, but that increased UV-B could mitigate this advantage. Seedlings were grown in open-top chambers in a greenhouse in ambient (360 μmol mol -1 ) and elevated (650 μmol mol-1) CO 2 , combined with ambient (1.56 to 8.66 kJ m -2 day -1 ) or increased (2.22 to 11.93 kJ m -2 day -1 ) biologically effective (weighted) UV-B irradiances. After 30 weeks, elevated CO 2 had no effect on biomass of A. karroo, despite increased net CO 2 assimilation rates. Interaction between UV-B and CO 2 on stomatal conductance was found, with conductances decreasing only where elevated CO 2 and UV-B were supplied separately. Increases in water use efficiencies, foliar starch concentrations, root nodule numbers and total nodule mass were measured in elevated CO 2 . Elevated UV-B caused only an increase in foliar carbon concentrations. In T. triandra, net CO 2 assimilation rates were unaffected in elevated CO 2 , but stomatal conductances and foliar nitrogen concentrations decreased, and water use efficiencies increased. Biomass of all vegetative fractions, particularly leaf sheaths, was increased in elevated CO 2 . and was accompanied by increased leaf blade lengths and individual leaf and leaf sheath masses. However, tiller numbers were reduced in elevated CO 2 . Significantly moderating effects of elevated UV-B were apparent only in individual masses of leaf blades and sheaths, and in total sheath and shoot biomass. The direct CO 2 -induced growth responses of the species therefore do not support the hypothesis of CO 2 -driven woody encroachment of C 4 grasslands. Rather, differential

  8. Interactive effects of herbicide and enhanced UV-B on growth, oxidative damage and the ascorbate-glutathione cycle in two Azolla species.

    Science.gov (United States)

    Prasad, Sheo Mohan; Kumar, Sushil; Parihar, Parul; Singh, Rachana

    2016-11-01

    A field experiment was conducted to investigate the impact of alone and combined exposures of herbicide pretilachlor (5, 10 and 20μgml(-1)) and enhanced UV-B radiation (UV-B1; ambient +2.2kJm(-2) day(-1) and UV-B2; ambient +4.4kJm(-2) day(-1)) on growth, oxidative stress and the ascorbate-glutathione (AsA-GSH) cycle in two agronomically important Azolla spp. viz., Azolla microphylla and Azolla pinnata. Decreased relative growth rate (RGR) in both the species under tested stress could be linked to enhanced oxidative stress, thus higher H2O2 accumulation was observed, that in turn might have caused severe damage to lipids and proteins, thereby decreasing membrane stability. The effects were exacerbated when spp. were exposed to combined treatments of enhanced UV-B and pretilachlor. Detoxification of H2O2 is regulated by enzymes/metabolites of AsA-GSH cycle such as ascorbate peroxidase (APX) and glutathione reductase (GR) activity that were found to be stimulated. While, dehydroascorabte reductase (DHAR) activity, and the amount of metabolites: ascorbate (AsA), glutathione (GSH) and ratios of reduced/oxidized AsA (AsA/DHA) and GSH (GSH/GSSG), showed significant reduction with increasing doses of both the stressors, either applied alone or in combination. Glutathione-S-transferase (GST), an enzyme involved in scavenging of xenobiotics, was found to be stimulated under the tested stress. This study suggests that decline in DHAR activity and in AsA/DHA ratio might have led to enhanced H2O2 accumulation, thus decreased RGR was noticed under tested stress in both the species and the effect was more pronounced in A. pinnata. Owing to better performance of AsA-GSH cycle in A. microphylla, this study substantiates the view that A. microphylla is more tolerant than A. pinnata. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. 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.

  10. 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 .

  11. 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

  12. 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

  13. Insulin-like growth factor I and II in 14 animal species and man as determined by three radioligand assays and two bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Zangger, I.; Zapf, J.; Froesch, E.R.

    1987-01-01

    Insulin-like growth factor I and II (IGF I and II) were determined by five different assays in human serum, in the sera of ten mammalian species and in chicken, turtle, and frog serum. Sera of all tested mammals contain two different IGFs corresponding to human immunoreactive IGF I and receptor reactive IGF II. Receptor reactive IGF II of most animal species does not show significant cross-reactivity in the RIA for human IGF II. IGF activity was also detected in sera of non-mammals, such as chicken and turtles, but not in frog serum. The IGF values obtained with the different assay system corresponded rather well: there is a good correlation between the values obtained in the protein binding and the fat cell assay, and between the results of the latter assays and the sum of immunoreactive IGF I and receptor reative IGF II. The results suggest that those regions in the IGF I and II molecules which are responsible for reactivity with the type I IGF and the insulin receptor have not essentially changed during evolution. Similarly, the C-region, which mainly determines the immunological properties of IGFs, appears to have remained relatively constant in the IGF I, but not in the IGF II molecule.

  14. [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).

  15. 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.

  16. A benzoxazine derivative induces vascular endothelial cell apoptosis in the presence of fibroblast growth factor-2 by elevating NADPH oxidase activity and reactive oxygen species levels.

    Science.gov (United States)

    Zhao, Jing; He, Qiuxia; Cheng, Yizhe; Zhao, Baoxiang; Zhang, Yun; Zhang, Shangli; Miao, Junying

    2009-09-01

    Previously, we found that 6,8-dichloro-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine (DBO) promoted apoptosis of human umbilical vascular endothelial cells (HUVECs) deprived of growth factors. In this study, we aimed to investigate the effect of DBO and its mechanism of action on angiogenesis and apoptosis of HUVECs in the presence of fibroblast growth factor-2 (FGF-2), which promotes angiogenesis and inhibits apoptosis in vivo and in vitro. DBO significantly inhibited capillary-like tube formation by promoting apoptosis of HUVECs in the presence of FGF-2 in vitro. Furthermore, DBO elevated the levels of reactive oxygen species (ROS) and nitric oxide (NO) and increased the activity of NADPH oxidase and inducible nitric oxide synthase (iNOS) in promoting apoptosis under this condition. Moreover, when NADPH oxidase was inhibited by its specific inhibitor, dibenziodolium chloride (DPI), DBO could not elevate ROS and NO levels in HUVECs. The data suggest that DBO is a new modulator of apoptosis in vitro, and it might function by increasing the activity of NADPH oxidase and iNOS, subsequently elevating the levels of ROS and NO in HUVECs. The findings of this study provide a new small molecule for investigating the FGF-2/NADPH oxidase/iNOS signaling pathway in apoptosis.

  17. 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.

  18. 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 < 0.05). The levels of -OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of -OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.

  19. Growth and nutritional status of Brazilian wood species Cedrella fissilis and Anadenanthera peregrina in bauxite spoil in response to arbuscular mycorrhizal inoculation and substrate amendment

    Directory of Open Access Journals (Sweden)

    Tótola Marcos Rogério

    2000-01-01

    Full Text Available The growth of Cedrella fissilis Vell. (Cedro Rosa and of Anadenanthera peregrina Benth (Angico Vermelho in bauxite spoil was studied to evaluate their response to substrate amendment or to inoculation with arbuscular mycorrhizal fungi (AMF. The plants were grown in bauxite spoil, topsoil or spoil amended with either topsoil or compost, and inoculated with the AMF Acaulospora scrobiculata, Gigaspora margarita or Glomus etunicatum. Root colonization was highly dependent on the interaction plant-fungus-substrate. In C. fissilis, root colonization by Gigaspora margarita dropped from 75% in bauxite spoil to only 4% in topsoil. Contrarily, root colonization of A. peregrina by the same fungus increased from 48% in spoil to 60% in topsoil. Root colonization of C. fissilis in topsoil was lower than in the three other substrates. The opposite was observed for A. peregrina. Inoculation of the plants with Acaulospora scrobiculata or Glomus etunicatum was very effective in promoting plant growth. Plants of both C. fissilis and A. peregrina did not respond to amendments of bauxite spoil unless they were mycorrhizal. Also, a preferential partitioning of photosynthates to the shoots of A. peregrina inoculated with G. etunicatum or A. scrobiculata, and of C. fissilis inoculated with any of the three species of AMF was observed. C. fissilis showed a greater response to mycorrhizal inoculation than A. peregrina. The mean mycorrhizal efficiency (ME for dry matter production by C. fissilis was 1,847% for A. scrobiculata, 1,922% for G. etunicatum, and 119% for G. margarita. In A. peregrina, the ME was 249% for A. scrobiculata, 540% for G. etunicatum, and 50% for G. margarita. The effect of mycorrhizal inoculation on plant growth seems to be related in part to an enhanced phosphorus absorption by inoculated plants. Moreover, the efficiency with which the absorbed nutrients were used to produce plant biomass was much greater in plants inoculated with A. scrobiculata or

  20. 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

  1. 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

  2. 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

  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

    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

  5. Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species.

    Science.gov (United States)

    Loydi, A; Donath, T W; Otte, A; Eckstein, R L

    2015-05-01

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Effects inoculation of mycorhizae species and irrigation levels impacts on growth criteria, yield and water use efficiency of corb (Zea mays L.

    Directory of Open Access Journals (Sweden)

    M.R. Amerian

    2016-05-01

    Full Text Available Water deficiency is one of the most important factors for limiting crop yield in arid and semiarid regions. Symbiosis with a variety of microorganisms in these regions is one of the modern ecological approaches for sustainable agriculture to reduce damages caused by environmental stresses. Symbiotic of arbuscular mycorrhizal fungi (AM with the roots of crops has shown positive effects on agricultural systems. In order to study the effects of inoculation with two species of mycorrhizal fungi and irrigation levels on root growth criteria and water use efficiency of corn, an experiment was performed as split plots based on a complete randomized block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad during growing season of 2008-2009. Treatments included two mycorhizae inoculation (Glomus mosseae and G. intraradices and control and four irrigation levels (25, 50, 75 and 100% of water requirement. Grain yield, root specific length, the percentage of root colonization and water use efficiency based on grain yield of corn were measured. The results showed that the effect of mycorrhizae inoculation was significant on (p≤0.05 root specific length, grain yield and water use efficiency of corn. Mycorrhizae species had no significant effect on root colonization percentage of corn. Different irrigation levels had significant effect on grain yield, special length root, the percentage of root colonization, and water use efficiency of corn (p≤0.05. Generally, the results showed that mycorrhizae inoculation in water deficiency conditions, can increase the uptake of water and nutrients by developing the root and increasing the absorbing surface. In this way, not only the plant tolerance against the water deficiency increases, but also more yield will be produced for a specific value of water, which means the water use efficiency increases. Furthermore, the use of water will be decreased.

  7. Ultraviolet B preconditioning enhances the hair growth-promoting effects of adipose-derived stem cells via generation of reactive oxygen species.

    Science.gov (United States)

    Jeong, Yun-Mi; Sung, Young Kwan; Kim, Wang-Kyun; Kim, Ji Hye; Kwack, Mi Hee; Yoon, Insoo; Kim, Dae-Duk; Sung, Jong-Hyuk

    2013-01-01

    Hypoxia induces the survival and regenerative potential of adipose-derived stem cells (ASCs), but there are tremendous needs to find alternative methods for ASC preconditioning. Therefore, this work investigated: (1) the ability of low-dose ultraviolet B (UVB) radiation to stimulate the survival, migration, and tube-forming activity of ASCs in vitro; (2) the ability of UVB preconditioning to enhance the hair growth-promoting capacity of ASCs in vivo; and (3) the mechanism of action for ASC stimulation by UVB. Although high-dose UVB decreased the proliferation of ASCs, low-dose (10 or 20 mJ/cm(2)) treatment increased their survival, migration, and tube-forming activity. In addition, low-dose UVB upregulated the expression of ASC-derived growth factors, and a culture medium conditioned by UVB-irradiated ASCs increased the proliferation of dermal papilla and outer root sheet cells. Notably, injection of UVB-preconditioned ASCs into C(3)H/HeN mice significantly induced the telogen-to-anagen transition and increased new hair weight in vivo. UVB treatment significantly increased the generation of reactive oxygen species (ROS) in cultured ASCs, and inhibition of ROS generation by diphenyleneiodonium chloride (DPI) significantly attenuated UVB-induced ASC stimulation. Furthermore, NADPH oxidase 4 (Nox4) expression was induced in ASCs by UVB irradiation, and Nox4 silencing by small interfering RNA, like DPI, significantly reduced UVB-induced ROS generation. These results suggest that the primary involvement of ROS generation in UVB-mediated ASC stimulation occurs via the Nox4 enzyme. This is the first indication that a low dose of UVB radiation and/or the control of ROS generation could potentially be incorporated into a novel ASC preconditioning method for hair regeneration.

  8. 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.

  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. Nitrogen-Utilization by Plant-Species from Acid Heathland Soils .2. Growth and Shoot/Root Partitioning of No3- Assimilation at Constant Low Ph and Varying No3-/Nh4+ Ratio

    NARCIS (Netherlands)

    Troelstra, S.R.; Wagenaar, R.; Smant, W.

    1995-01-01

    The growth of four heathland species, two grasses (D. flexuosa, M. caerulea) and two dwarf shrubs (C. vulgaris, E. tetralix), was tested in solution culture at pH 4.0 with 2 mol m(-3) N, varying the NO3-/NH4+ ratio up to 40% nitrate. In addition, measurements of NRA, plant chemical composition, and

  11. 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.

  12. 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

  13. 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.

  14. A novel small molecule, Rosline, inhibits growth and induces caspase-dependent apoptosis in human lung cancer cells A549 through a reactive oxygen species-dependent mechanism.

    Science.gov (United States)

    Zhao, Ting; Feng, Yang; Jin, Wenling; Pan, Hui; Li, Haizhou; Zhao, Yang

    2016-06-01

    Chemical screening using synthetic small molecule libraries has provided a huge amount of novel active molecules. It generates lead compound for drug development and brings focus on molecules for mechanistic investigations on many otherwise intangible biological processes. In this study, using non-small cell lung cancer cell A549 to screen against a structurally novel and diverse synthetic small molecule library of 2,400 compounds, we identified a molecule named rosline that has strong anti-proliferation activity on A549 cells with a 50% cell growth inhibitory concentration (IC50 ) of 2.87 ± 0.39 µM. We showed that rosline treatment increased the number of Annexin V-positive staining cell, as well as G2/M arrest in their cell cycle progression. Further, we have demonstrated that rosline induces a decrease of mitochondrial membrane potential (Δφm ) and an increase of caspases 3/7 and 9 activities in A549 cells, although having no effect on the activity of caspase 8. Moreover, we found that rosline could induce the production of reactive oxygen species (ROS) and inhibit the phosphorylation of signaling molecule Akt in A549 cells. Alternatively, an antioxidant N-acetyl-L-cysteine (NAC) significantly attenuated rosline's effects on the mitochondrial membrane potential, caspases 3/7 and 9 activities, cell viabilities and the phosphorylation of Akt. Our results demonstrated that ROS played an important role in the apoptosis of A549 cells induced by rosline. © 2016 International Federation for Cell Biology.

  15. 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.

  16. Comparison of Cultivars and Seasonal Variation in Blueberry (Vaccinium Species) Leaf Extract on Adult T-Cell Leukemia Cell Line Growth Suppression.

    Science.gov (United States)

    Kai, Hisahiro; Fuse, Takuichi; Kunitake, Hisato; Morishita, Kazuhiro; Matsuno, Koji

    2014-06-30

    The inhibitory effects of blueberry leaves on the proliferation of adult T-cell leukemia (ATL) cell lines have previously been reported. A comparison of blueberry leaf extracts from different cultivars and seasonal variation were investigated regarding their effects on ATL cell line proliferation. The inhibitory effects of 80% ethanol leaf extracts from different blueberry cultivars collected from April to December in 2006 or 2008 were evaluated using two ATL cell lines. The bioactivities of leaf extracts of rabbit-eye blueberry ( Vaccinium virgatum Aiton; RB species), southern highbush blueberry ( V. spp.; SB species), northern highbush blueberry ( V. corymbosum L.; NB species), and wild blueberry ( V. bracteatum Thunb.; WB species) were compared. Of these, leaves of the RB species collected in December showed a significantly stronger inhibitory effect in both cell lines than the SB, NB, or WB species. These results suggest elevated biosynthesis of ATL-preventative bioactive compounds in the leaves of the RB species before the defoliation season.

  17. Vascular endothelial growth factor up-regulates the expression of intracellular adhesion molecule-1 in retinal endothelial cells via reactive oxygen species, but not nitric oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-ling; WEN Liang; CHEN Yan-jiong; ZHU Yi

    2009-01-01

    Background The vascular endothelial growth factor (VEGF) is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 (ICAM-1) is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells (ECs) is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs.Methods Bovine retinal ECs (BRECs) were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF (100 ng/ml) and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase (eNOS) were detected using Western blotting. Griess reaction was used to detect nitric oxide (NO).Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C (PKC) altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase (PI3K) or reactive oxygen species (ROS) significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased.Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.

  18. Reactive oxygen species via redox signaling to PI3K/AKT pathway contribute to the malignant growth of 4-hydroxy estradiol-transformed mammary epithelial cells.

    Directory of Open Access Journals (Sweden)

    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

  19. Studies of metallic species incorporation during growth of SrBi2Ta2O9 films on YBa2Cu3O7-x substrates using mass spectroscopy of recoiled ions

    International Nuclear Information System (INIS)

    Dhote, A. M.

    1999-01-01

    The incorporation of metallic species (Bi, Sr and Ta) during the growth of layered perovskite SrBi 2 Ta 2 O 9 (SBT) on a-axis oriented YBa 2 Cu 3 O 7-x (YBCO) conducting oxide substrates has been investigated using in situ low energy mass spectroscopy of recoiled ions (MSRI). This technique is capable of providing monolayer-specific surface information relevant to the growth of single and multi-component thin films and layered heterostructures. The data show a temperature dependence of metallic species incorporation during co-deposition of Sr, Bi and Ta on YBCO surfaces. At high temperatures (400 400 C. SBT films grown at temperatures ≤ 400 C and annealed in oxygen or air at 800 C exhibit a polycrystalline structure with partial a-axis orientation

  20. Utilization of lightflecks by seedlings of five dominant tree species of different subtropical forest successional stages under low-light growth conditions.

    Science.gov (United States)

    Zhang, Q; Chen, Y J; Song, L Y; Liu, N; Sun, L L; Peng, C L

    2012-05-01

    We selected five typical tree species, including one early-successional species (ES) Pinus massoniana Lamb., two mid-successional species (MS) Schima superba Gardn. et Champ. and Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils. and two late-successional species (LS) Cryptocarya concinna Hance. and Acmena acuminatissima (BI.) Merr et Perry., which represent the plants at three successional periods in Dinghushan subtropical forest succession of southern China. Potted seedlings of the five species were grown under 12% of full sunlight for 36 months. The ES and MS showed the slowest and fastest responses to lightflecks, respectively, which correlated with the rate of stomatal opening. In contrast to P. massoniana and C. concinna, the other three species exhibited a high induction loss. Early-successional species showed the lowest specific leaf area and chlorophyll content, the highest photosynthetic capacity (A(max)) and respiratory carbon losses (R(d)). Compared with ES and MS, LS showed lower A(max) and R(d). The five tree species showed a similar chlorophyll a/b ratio after long-term low-light adaptations. On the other hand, LS had a relatively higher de-epoxidation state to protect themselves from excess light during lightflecks. Our results indicated that (i) slower responses to lightflecks could partially explain why ES species could not achieve seedling regeneration in low-light conditions; (ii) fast responses to lightflecks could partially explain why MS species could achieve seedling regeneration in low-light conditions; and (iii) smaller respiratory carbon losses might confer on the LS species a competitive advantage in low-light conditions.

  1. Whole-tree silvic identifications and the microsatellite genetic structure of a red oak species complex in an Indiana old-growth forest

    Science.gov (United States)

    Preston R. Aldrich; George R. Parker; Charles H. Michler; Jeanne Romero-Severson

    2003-01-01

    The red oaks (Quercus section Lobatae) include important timber species, but we know little about their gene pools. Red oak species can be difficult to identify, possibly because of extensive interspecific hybridization, although most evidence of this is morphological. We used 15 microsatellite loci to examine the genetic...

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. Arsenic-resistant and plant growth-promoting Firmicutes and γ-Proteobacteria species from industrially polluted irrigation water and corresponding cropland.

    Science.gov (United States)

    Qamar, N; Rehman, Y; Hasnain, S

    2017-09-01

    The aim of the study was to explore irrigation water polluted with industrial waste and corresponding cropland to screen bacteria for As detoxification and plant growth promotion. Plant growth-promoting (PGP) As-resistant cropland bacteria were isolated from contaminated irrigation water and corresponding agricultural soil. Phylogenetic analysis revealed that the isolates belonged to two distinct bacterial lineages; Firmicutes and γ-Proteobacteria. Maximum As(V) resistance was exhibited by Klebsiella pneumoniae T22 and Klebsiella oxytoca N53 (550 mmol l -1 ), whereas maximum resistance against As(III) was exhibited by K. oxytoca N53 (200 mmol l -1 ). Maximum As(V) reduction was shown by K. pneumoniae T22 (6·7 mmol l -1 ), whereas maximum As(III) oxidation was exhibited by Bacillus subtilis T23 (4·8 mmol l -1 ). As resistance genes arsB and ACR3 were detected in many of the isolates through polymerase chain reaction. Many of these isolates exhibited PGP traits such as hydrogen cyanide and auxin production as well as phosphate solubilization. The bacterial strains were able to enhance Triticum aestivum growth both in the absence and presence of As, and statistically significant increase in shoot and root lengths was observed especially in case of Acinetobacter lwoffii T24 and Citrobacter freundii N52-treated plants. Cropland bacteria have the ability to support plant growth. Bacteria of croplands irrigated with industrially polluted water develop resistance against toxicants. These bacteria are helpful for the plant growth in such contaminated lands. The bacteria capable of both As detoxification and plant growth promotion, such as A. lwoffii T24 and C. freundii N52, are ideal for remediation and reclamation of polluted lands for agriculture purposes. © 2017 The Society for Applied Microbiology.

  7. The potential of Vachellia kosiensis (Acacia kosiensis) as a dryland forestry species in terms of its water use, growth rates and resultant water-use efficiency

    CSIR Research Space (South Africa)

    Gush, Mark B

    2017-01-01

    Full Text Available , their correspondingly low water-use rates indicated that the indigenous trees had similar biophysical water-use efficiency values compared with genetically improved introduced tree species and highlighted their potential as an attractive land-use option in appropriate...

  8. 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

  9. 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,

  10. 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...

  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. 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

  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. The Good, the Bad and the Plenty: Interactive Effects of Food Quality and Quantity on the Growth of Different Daphnia Species

    NARCIS (Netherlands)

    Bukovinszky, T.; Verschoor, A.M.; Helmsing, N.R.; Bezemer, T.M.; Bakker, E.S.; Vos, M.; De Senerpont Domis, L.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

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

    NARCIS (Netherlands)

    Bukovinszky, T.; Verschoor, A.M.; Helmsing, N.R.; Bezemer, T.M.; Bakker, E.S.; Vos, M.; Domis, L.N.D.

    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

  16. Effects of anaerobic growth conditions on biomass accumulation, root morphology, and efficiencies of nutrient uptake and utilization in seedlings of some southern coastal plain pine species

    International Nuclear Information System (INIS)

    Topa, M.A.

    1984-01-01

    Seedlings of pond (Pinus serotina (Michx.)), sand (P. clausa (Engelm.) Sarg.), and loblolly pines (P. taeda L., drought-hardy and wet site seed sources) were grown in a non-circulating, continuously-flowing solution culture under anaerobic or aerobic conditions to determine the effects of anaerobics on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond pines was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with specific morphological changes which enhanced root internal aeration. Oxygen transport from shoot to the root in anaerobically-grown loblolly and pond pine seedlings was demonstrated via rhizosphere oxidation experiments. Tissue elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term 32 p uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass, since H 2 PO 4 - influx in the anaerobically-grown seedlings was more than twice that of their aerobic counterparts. Sand pine possessed the physiological but not morphological capacity to increase P uptake under anaerobic growth conditions. Pond and wet-site loblolly pine seedlings maintained root growth, perhaps through enhanced internal root aeration - an advantage in field conditions where the phosphorus supply may be limited or highly localized

  17. 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

  18. Standardization and optimization of core sampling procedure for carbon isotope analysis in eucalyptus and variation in carbon isotope ratios across species and growth conditions

    CSIR Research Space (South Africa)

    Raju, M

    2011-11-01

    Full Text Available C Aspect grandis urophylla Variation in D13C 16.000 16.500 17.000 17.500 18.000 18.500 19.000 19.500 20.000 20.500 E. camal E urophylla E grandis E pellita E globulus D1 3C Variable N Level of significance Species 2 P<0...

  19. 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.

  20. 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)

  1. Use of soybean meal and papain to partially replace animal protein for culturing three marine fish species: Fish growth and water quality.

    Science.gov (United States)

    Mo, W Y; Lau, R S S; Kwok, A C K; Wong, M H

    2016-12-01

    The main aim of this study was to investigate the feasibility of using soybean meal added with papain to replace half of the fishmeal used in the moist pellets (49% fishmeal and 45% trash fish) developed by the Hong Kong Agriculture, Fisheries and Conservation Department (AFCD) for culturing marine fish. Gold-lined seabream (Rhabdosargus sarba), brown spotted grouper (Epinephelus bleekeri) and pompano (Trachinotus blochii) were farmed at one of the research stations (Kat-O) of AFCD, for a period of 340 days. Results indicated that diets containing papain resulted in better fish growth (reflected by relative weight gain and feed conversion ratio) than diets without papain. In general, wet weight gain of fish depends on the amount of papain added in diet rather than the diet composition. Soybean used in conjunction with papain also contributed to a more effective growth than fish fed with the moist pellets alone. A laboratory experiment (using tanks) was conducted to study the effects of the diets on concentrations of ammonia, nitrite and nitrate in the tank water. Results showed that concentrations of ammonia and nitrate were significantly lower (p marine fish and lower the adverse impact of trash fish and fishmeal on water quality of the mariculture zones. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 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.

  4. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    Science.gov (United States)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

    2015-10-01

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 1016 to 3.8 × 1019 cm-3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1-2 × 1015 cm-3. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the dramatically enhanced growth rates demonstrate

  5. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan, E-mail: alan.doolittle@ece.gatech.edu [Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Bresnahan, Rich C. [Veeco Instruments, St. Paul, Minnesota 55127 (United States)

    2015-10-21

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N{sub 2} while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N{sub 2} and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10{sup 16} to 3.8 × 10{sup 19} cm{sup −3} were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10{sup 15} cm{sup −3}. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be

  6. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    International Nuclear Information System (INIS)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

    2015-01-01

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N 2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N 2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10 16 to 3.8 × 10 19 cm −3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10 15 cm −3 . The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the

  7. 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 that microbial activity and nutrient cycling, which fulfill a key role for plant development, were higher in CSB. Therefore, irrigation of 40% can

  8. High throughput phenotypic selection of Mycobacterium tuberculosis mutants with impaired resistance to reactive oxygen species identifies genes important for intracellular growth.

    Directory of Open Access Journals (Sweden)

    Olga Mestre

    Full Text Available Mycobacterium tuberculosis has the remarkable capacity to survive within the hostile environment of the macrophage, and to resist potent antibacterial molecules such as reactive oxygen species (ROS. Thus, understanding mycobacterial resistance mechanisms against ROS may contribute to the development of new anti-tuberculosis therapies. Here we identified genes involved in such mechanisms by screening a high-density transposon mutant library, and we show that several of them are involved in the intracellular lifestyle of the pathogen. Many of these genes were found to play a part in cell envelope functions, further strengthening the important role of the mycobacterial cell envelope in protection against aggressions such as the ones caused by ROS inside host cells.

  9. Crescimento e composição química de dez espécies de microalgas marinhas em cultivos estanques Growth and chemical composition of ten species of marine microalgae in batch cultures

    Directory of Open Access Journals (Sweden)

    Viviane Borges-Campos

    2010-02-01

    Full Text Available Microalgas apresentam diversas aplicações econômicas consagradas, como usos na aquicultura e na indústria de alimentos, havendo buscas por novos usos, como a geração de biomassa para produção de biodiesel. As possíveis aplicações estão diretamente relacionadas à taxa de crescimento e ao perfil químico das espécies. Assim, a seleção de condições que promovam o aproveitamento da biomassa algácea é fundamental para sua utilização econômica. Neste estudo, 10 espécies de microalgas marinhas foram cultivadas e comparadas quanto ao crescimento e à composição química. Foram observadas diferenças na velocidade de crescimento, com espécies de células menores crescendo mais rapidamente que microalgas maiores. Teores de proteínas, carboidratos, lipídeos e pigmentos fotossintetizantes variaram amplamente entre as espécies, sendo as proteínas as substâncias mais abundantes. Todas as espécies apresentaram concentrações de ácidos aminados semelhantes, sendo os ácidos aspártico e glutâmico os mais abundantes. Algumas espécies apresentaram altas concentrações de ácidos graxos de importância econômica, como os ácidos eicosapentaenoico e linoleico. O balanço dos resultados indica que há poucas tendências gerais relacionadas a grandes grupos taxonômicos.Microalgae show several economic applications, such as uses in aquaculture and in food industry, and there is a search for new uses, such as the biomass production to convert into biodiesel. All possible applications are directly linked to growth rate and the chemical profile of the species. Thus, the selection of conditions to promote a better use of algal biomass is fundamental for economic purposes. In this study, 10 species of marine microalgae were cultured and compared for growth and chemical composition. Remarkable differences of growth performance have been observed, with species with small cell volumes growing faster than species with large cell volumes

  10. Influencia de diferentes especies de fungo micorrizico arbuscular no desenvolvimento do crisântemo Influence of different species of arbuscular mycorrhizal fungi on chrysanthemum growth

    Directory of Open Access Journals (Sweden)

    Adriana Parada Dias da Silveira

    1996-01-01

    Full Text Available Com o objetivo de verificar o desenvolvimento e florescimento do crisântemo (Dendranthema grandiflora na presença de micorriza arbuscular, foi instalado, em casa de vegetação, um experimento, empregando-se os fungos Gigaspora margarita, Glomus leptotichum, Glomus macrocarpum e Scutellospora heterogama. Utilizou-se terra roxa estruturada, da Série Luiz de Queiroz, esterilizada (por autoclavagem e não esterilizada. No florescimento, colheram-se as plantas e determinaram-se a altura, a matéria seca da parte aérea, a matéria fresca da raiz, o teor de P e K na parte aérea, a colonização micorrízica e o número de esporos do fungo micorrízico. O desenvolvimento e o florescimento foram favorecidos pela inoculação de G. leptotichum e G.macrocarpum, quando as plantas foram cultivadas em solo esterilizado, superando o efeito dos fungos micorrízicos nativos. Entretanto, no solo não esterilizado, a inoculação dessas espécies de fungo não promoveu aumento no desenvolvimento da planta.A greenhouse experiment was conducted to verify the effect of arbuscular mycorrhiza on growth and flowering of chrysanthemum. Rooted plants were inoculated with Gigaspora margarita, Glomus leptotichum, Glomus macrocarpum e Scutellospora heterogama or non-inoculated. Plants were grown in a autoclave sterilized, and non-sterilized soil of the type "Terra Roxa Estruturada". At the flowering stage, plants were harvested and measured for plant height, shoot dry matter, root fresh matter, shoot P and K content, mycorrhizal root colonization and number of mycorrhizal fungi spores. Plants colonized with G.leptotichum and G. macrocarpum presented higher growth and flowering than control plants, in sterilized soil, overcoming the effect of native mycorrhizal fungi. However, there was no effect of introduced mycorrhizal fungi on non-sterilized soil.

  11. The Effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD on the Mortality and Growth of Two Amphibian Species (Xenopus laevis and Pseudacris triseriata

    Directory of Open Access Journals (Sweden)

    Alex Collier

    2008-12-01

    Full Text Available We observed a slight drop in the growth of Xenopus laevis and Pseudacris triseriata larvae following acute exposure (24-48 h during egg development to three concentrations of TCDD (0.3, 3.0, 30.0 μg/l. Our exposure protocol was modeled on a previous investigation that was designed to mimic the effects of maternal deposition of TCDD. The doses selected were consistent with known rates of maternal transfer between mother and egg using actual adult body burdens from contaminated habitats. Egg and embryonic mortality immediately following exposure increased only among 48 h X. laevis treatments. Control P. triseriata and X. laevis completed metamorphosis more quickly than TCDDtreated animals. The snout-vent length of recently transformed P. triseriata did not differ between treatments although controls were heavier than high-dosed animals. Likewise, the snout-vent length and weight of transformed X. laevis did not differ between control and TCDD treatments. These findings provide additional evidence that amphibians, including P. triseriata and X. laevis are relatively insensitive to acute exposure to TCDD during egg and embryonic development. Although the concentrations selected for this study were relatively high, they were not inconsistent with our current understanding of bioaccumulation via maternal transfer.

  12. Evaluation of bread crumbs as a potential carbon source for the growth of thraustochytrid species for oil and omega-3 production.

    Science.gov (United States)

    Thyagarajan, Tamilselvi; Puri, Munish; Vongsvivut, Jitraporn; Barrow, Colin J

    2014-05-23

    The utilization of food waste by microorganisms to produce omega-3 fatty acids or biofuel is a potentially low cost method with positive environmental benefits. In the present study, the marine microorganisms Thraustochytrium sp. AH-2 and Schizochytrium sp. SR21 were used to evaluate the potential of breadcrumbs as an alternate carbon source for the production of lipids under static fermentation conditions. For the Thraustochytrium sp. AH-2, submerged liquid fermentation with 3% glucose produced 4.3 g/L of biomass and 44.16 mg/g of saturated fatty acids after seven days. Static fermentation with 0.5% and 1% breadcrumbs resulted in 2.5 and 4.7 g/L of biomass, and 42.4 and 33.6 mg/g of saturated fatty acids, respectively. Scanning electron microscopic (SEM) studies confirmed the growth of both strains on breadcrumbs. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy for both strains were consistent with the utilization of breadcrumbs for the production of unsaturated lipids, albeit at relatively low levels. The total lipid yield for static fermentation with bread crumbs was marginally lower than that of fermentation with glucose media, while the yield of unsaturated fatty acids was considerably lower, indicating that static fermentation may be more appropriate for the production of biodiesel than for the production of omega-3 rich oils in these strains.

  13. Evaluation of Bread Crumbs as a Potential Carbon Source for the Growth of Thraustochytrid Species for Oil and Omega-3 Production

    Directory of Open Access Journals (Sweden)

    Tamilselvi Thyagarajan

    2014-05-01

    Full Text Available The utilization of food waste by microorganisms to produce omega-3 fatty acids or biofuel is a potentially low cost method with positive environmental benefits. In the present study, the marine microorganisms Thraustochytrium sp. AH-2 and Schizochytrium sp. SR21 were used to evaluate the potential of breadcrumbs as an alternate carbon source for the production of lipids under static fermentation conditions. For the Thraustochytrium sp. AH-2, submerged liquid fermentation with 3% glucose produced 4.3 g/L of biomass and 44.16 mg/g of saturated fatty acids after seven days. Static fermentation with 0.5% and 1% breadcrumbs resulted in 2.5 and 4.7 g/L of biomass, and 42.4 and 33.6 mg/g of saturated fatty acids, respectively. Scanning electron microscopic (SEM studies confirmed the growth of both strains on breadcrumbs. Attenuated total reflection Fourier transform infrared (ATR-FTIR spectroscopy for both strains were consistent with the utilization of breadcrumbs for the production of unsaturated lipids, albeit at relatively low levels. The total lipid yield for static fermentation with bread crumbs was marginally lower than that of fermentation with glucose media, while the yield of unsaturated fatty acids was considerably lower, indicating that static fermentation may be more appropriate for the production of biodiesel than for the production of omega-3 rich oils in these strains.

  14. Function of SSA subfamily of Hsp70 within and across species varies widely in complementing Saccharomyces cerevisiae cell growth and prion propagation.

    Directory of Open Access Journals (Sweden)

    Deepak Sharma

    2009-08-01

    Full Text Available The cytosol of most eukaryotic cells contains multiple highly conserved Hsp70 orthologs that differ mainly by their spatio-temporal expression patterns. Hsp70s play essential roles in protein folding, transport or degradation, and are major players of cellular quality control processes. However, while several reports suggest that specialized functions of Hsp70 orthologs were selected through evolution, few studies addressed systematically this issue.We compared the ability of Ssa1p-Ssa4p from Saccharomyces cerevisiae and Ssa5p-Ssa8p from the evolutionary distant yeast Yarrowia lipolytica to perform Hsp70-dependent tasks when expressed as the sole Hsp70 for S. cerevisiae in vivo. We show that Hsp70 isoforms (i supported yeast viability yet with markedly different growth rates, (ii influenced the propagation and stability of the [PSI(+] and [URE3] prions, but iii did not significantly affect the proteasomal degradation rate of CFTR. Additionally, we show that individual Hsp70 orthologs did not induce the formation of different prion strains, but rather influenced the aggregation properties of Sup35 in vivo. Finally, we show that [URE3] curing by the overexpression of Ydj1p is Hsp70-isoform dependent.Despite very high homology and overlapping functions, the different Hsp70 orthologs have evolved to possess distinct activities that are required to cope with different types of substrates or stress situations. Yeast prions provide a very sensitive model to uncover this functional specialization and to explore the intricate network of chaperone/co-chaperone/substrates interactions.

  15. 光温条件和pH对浮萍生长及磷吸收的影响%Effect of Photon Flux Density and pH on Growth Ability and Phosphorus Removal Efficiency of Two Duckweed Species

    Institute of Scientific and Technical Information of China (English)

    蔡树美; 张震; 辛静; 周雄飞; 钱晓晴

    2011-01-01

    试验以长江三角洲地区常见的稀脉浮萍和少根紫萍为研究对象.在Hoagland's E-Medium营养液进行实验室模拟培养的基础上,研究了光温条件以及pH对两种浮萍生长和磷去除能力的影响.结果表明,在1500-6000 1x光照强度范围内,光照越强,两种浮萍的生长和磷去除能力越强;在10-35℃温度范围内,两种浮萍生长和磷去除的最佳气温为25℃,高温和低温对浮萍的生长都有一定的抑制作用,且低温的抑制作用更明显;在pH5~9范围内,稀脉浮萍和少根紫萍生长和磷去除的最佳pH值分别为6.0和5.0,越偏离最佳生长pH值,pH对浮萍生长和磷去除的抑制效果越明显.%Effect of photon flux density,temperature and pH on growth ability and phosphorus removal efficiency of Lemna aequinoctialis and Spirodela oligorrhiza, which are common species in Yangtze Delta region,was assessed with laboratory artificial culture experiments using Hoagland's E-Medium. Results indicated that the stronger photon flux density was,higher growth ability and phosphorus removal efficiency of duckweeds would become in photon flux density range of 1 500~6 000tx.The optimal temperature condition for duckweeds growth and phosphorus removal was 25 ℃ among temperature from 10 ℃ to 35 ℃. Either low or high temperature would lead to reduce the growth rate of duckweed,and restrain effect of low temperature was more significant. Among pH fora 5 to 9,the optimal pH condition for Lemna aequinoctialis and Spirodela oligorrhiza was pH 6.0 and 5.0 respectively. Deviation from the optimal pH value caused a distinct restrain of both growth ability and phosphorus removal efficiency.

  16. Potencial alelopático de espécies nativas na germinação e crescimento inicial de Lactuca sativa L. (Asteraceae Allelopathic potential of native species in Lactuca sativa L. (Asteraceae germination and initial growth

    Directory of Open Access Journals (Sweden)

    Fabiana Maraschin-Silva

    2006-03-01

    Full Text Available A alelopatia caracteriza-se pelos efeitos danosos ou benéficos sobre o desenvolvimento da vegetação, causados por substâncias químicas produzidas e liberadas para o ambiente por uma planta. Com o objetivo de avaliar o potencial alelopático de espécies brasileiras, foram testados extratos foliares de Cecropia pachystachya Trec. (Urticaceae, Peltophorum dubium (Spreng. Taub. (Fabaceae, Psychotria leiocarpa Cham. & Schltdl (Rubiaceae, Sapium glandulatum (Vell. Pax (Euphorbiaceae e Sorocea bonplandii (Baill. Burg., Lanj. & Boer (Moraceae, utilizando-se bioensaios de germinação e crescimento e alface (Lactuca sativa L. como planta alvo. Nesses bioensaios, foram usados extratos foliares aquosos nas concentrações de 2 e 4%, preparados por maceração estática com água fria e quente. Os extratos das cinco espécies causaram atraso na germinação dos aquênios da alface, bem como efeitos tóxicos no crescimento das plântulas, com redução e enfraquecimento das raízes. Os resultados obtidos mostraram a presença de substâncias químicas inibidoras nos extratos, revelando potencial alelopático para as cinco espécies avaliadas.Allelopathy is characterized by harmful or beneficial effects on vegetation development, caused by chemical substances produced and released into the environment by the plant. Aiming to assess the allelopathic potential of Brazilian species, aqueous leaf extracts of Cecropia pachystachya Trec. (Urticaceae, Peltophorum dubium (Spreng. Taub. (Fabaceae, Psychotria leiocarpa Cham. & Schltdl (Rubiaceae, Sapium glandulatum (Vell. Pax (Euphorbiaceae, and Sorocea bonplandii (Baill. Burger, Lanj. & Boer (Moraceae were tested on lettuce using germination and growth bioassays. In these bioassays, aqueous leaf extracts were used at concentrations of 2 and 4%, prepared by static maceration with cold and hot water. The five species extracts delayed lettuce germination and produced toxic effects on seedling growth, with root

  17. Crescimento e teor de metais de mudas de espécies arbóreas cultivadas em solo contaminado com metais pesados Growth and metal concentration of seedlings of woody species in a heavy metal contaminated soil

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Lara Lanza de Sá e Melo Marques

    2000-01-01

    Full Text Available O objetivo do trabalho foi avaliar o teor de metais pesados e o crescimento de mudas de 20 espécies arbóreas tropicais em solo com elevado grau de contaminação com metais pesados. Em casa de vegetação, as mudas foram transplantadas para vasos contendo 3,3 kg de misturas com diferentes proporções (0, 20, 40 e 60% v/v de solo contaminado. Verificou-se comportamento diferenciado das espécies quanto à inibição de crescimento e aos teores de metais na raiz e na parte aérea em decorrência da contaminação. Com base na produção de matéria seca da parte aérea, concluiu-se que apenas Myrsine umbellata, Cedrella fissilis, Tabebuia impetiginosa e Copaifera langsdorffii não foram afetadas pela contaminação, enquanto Hymenaea courbaril, Mimosa caesalpiniaefolia, Acacia mangium e Platypodium gonoacantha sofreram pequeno impacto. As demais espécies foram muito inibidas pela contaminação do solo, o que é causado pela absorção, na maioria dos casos, de Zn e Cd. Várias espécies apresentaram elevada capacidade de reter esses metais nas raízes, evitando sua translocação para a parte aérea.The objective of the paper was to evaluate metal content and ability to grow in soil with excess of heavy metals of seedlings of 20 woody species. In the greenhouse, seedlings were transplanted to pots with 3.3 kg of soil-mixes with different proportions (0, 20, 40, 60% v/v of a heavy metal contaminated soil. It was found that plant species behaved differently in terms of growth inhibition and metal content in the shoots and roots. Based upon the dry matter yield, only Myrsine umbellata, Cedrella fissilis, Tabebuia impetiginosa and Copaifera langsdorffii were not affected by increasing contamination, whereas Hymenaea courbaril, Mimosa caesalpiniaefolia, Acacia mangium and Platypodium gonoacantha were only slightly affected by it. All the other species were highly inhibited by the excess of metals in the soil, being such effects related, in most

  18. Crescimento alométrico, morfologia e uso do habitat em cinco espécies de Mabuya Fitzinger (Reptilia, Scincidae Allometric growth, morphology and habitat use in five species of Mabuya Fitzinger (Reptilia, Scincidae

    Directory of Open Access Journals (Sweden)

    Gabriel Silva Pinto

    2004-06-01

    Full Text Available Foram analisadas a variação ontogenética da forma do corpo nos lagartos sul-americanos Mabuya agilis, M. bistriata, M. guaporicola, M. macrorhyncha e M. nigropunctata, assim como as diferenças interespecíficas nas proporções do corpo, como resultados de um possível crescimento alométrico. As trajetórias das tendências ontogenéticas foram significativamente diferentes somente entre M. guaporicola e M. nigropunctata; todos os pares de espécies, exceto M. agilis e M. macrorhyncha, M. bistriata e M. nigropunctata, demonstraram diferenças significativas em relação ao intercepto Y. A Análise de Componentes Principais aplicada sobre uma série de caracteres morfométricos demonstrou sinais opostos para as variáveis do corpo e dos membros, corroborando estudos anteriores. Contudo, quando as espécies foram analisadas individualmente, as mãos e dígitos apresentaram alometria negativa, enquanto os demais segmentos apresentaram variação em suas alometrias. Algumas hipóteses levantadas nesse estudo, relacionadas à forma do corpo e ao uso do hábitat nessas espécies, necessitam ser testadas.The ontogenetic variation of body shape in the South American skinks Mabuya agilis Boulenger, 1887, M. bistriata (Spix, 1825, M. guaporicola Dunn, 1936, M. macrorhyncha Hoge, 1946, and M. nigropunctata (Spix, 1825 were analyzed. Interspecific differences in body proportions as a possible result of allometric growth in these species are also examined. Ontogenetic trend lines were significantly different only between M. guaporicola and M. nigropunctata; all other species pairs, except M. agilis and M. macrorhyncha, M. bistriata and M. nigropunctata, showed significantly different Y intercepts. A PCA analysis on a series of morphometric characters showed opposite signals for body and limb variables, corroborating previous studies. However, when the species were analyzed separately, hand and digits were the most likely segments to present negative

  19. Physiological and Growth Characteristics of Shewanella Species

    Science.gov (United States)

    2016-05-01

    with B vitamins in the MMB. After the addition of riboflavin, DPV scans revealed a peak at -0.419 ± 0.005 V; n = 3. DPV scans performed on CF 31 h...0.008. The DM was supplemented with Wolfe’s mineral and vitamin solutions [20]. Peptone and yeast extract were omitted and replaced with high-purity...containing MB, cell elongation was observed when cultures entered stationary phase. Under DM conditions, agarose was in excess throughout the

  20. Clonal growth and plant species abundance

    Czech Academy of Sciences Publication Activity Database

    Herben, Tomáš; Nováková, Z.; Klimešová, Jitka

    2014-01-01

    Roč. 114, č. 2 (2014), s. 377-388 ISSN 0305-7364 R&D Projects: GA ČR GA526/09/0963 Institutional support: RVO:67985939 Keywords : clonal plants * frequency * plant communities of Central Europe Subject RIV: EF - Botanics Impact factor: 3.654, year: 2014

  1. Species choice, provenance and species trials among native Brazilian species

    Energy Technology Data Exchange (ETDEWEB)

    Drumond, M A

    1982-01-01

    Six papers from the conference are presented. Drumond, M.A., Potential of species native to the semi-arid tropics, 766-781, (Refs. 18), reports on Anadenanthera macrocarpa, Mimosa species, Schinopsis brasiliensis, Spondias tuberosa, Ziziphus joazeiro, Cnidoscolus phyllacanthus, Bursera leptophleos (leptophloeos), Tabebuia impetiginosa, Astronium urundeuva, and Mimosa caesalpinia. Monteiro, R.F.R., Speltz, R.M., Gurgel, J.T. do A.; Silvicultural performance of 24 provenances of Araucaria angustifolia in Parana, 814-824, (Refs. 8). Pires, C.L. da S., Kalil Filho, A.N., Rosa, P.R.F. da, Parente, P.R., Zanatto, A.C.S.; Provenance trials of Cordia alliodora in the State of Sao Paulo, 988-995, (Refs. 9). Nogueira, J.C.B., Siqueira, A.C.M.F., Garrido, M.A.O., Gurgel Garrido, L.M. do A., Rosa, P.R.F., Moraes, J.L. de, Zandarin, M.A., Gurgel Filho, O.A., Trials of some native species in various regions of the State of Sao Paulo, 1051-1063, (Refs. 9) describes Centrolobium tomentosum, Peltophorum dubium, Tabebuia vellosoi, Cariniana legalis, and Balfourodendron riedelianum. Batista, M.P., Borges, J.F., Franco, M.A.B.; Early growth of a native species in comparison with exotics in northeastern Para, Brazil, 1105-1110, (Refs. 3). Jacaranda copaia is compared with Gmelina arborea, Pinus caribaea various hondurensis, Eucalyptus deglupta, and E. urophylla. Lima, P.C.F., Souza, S.M. de, Drumond, M.A.; Trials of native forest species at Petrolina, Pernambuco, 1139-1148, (Refs. 8), deals with Anadenanthera macrocarpa, Piptadenia obliqua, Pithecellobium foliolosum, Astronium urundeuva, Schinopsis brasiliensis, Cassia excelsa, Caesalpinia pyramidalis, Parkia platycephala, Pseudobombax simplicifolium, Tabebuia impetiginosa, Caesalpinia ferrea, and Aspidosperma pyrifolium. 18 references.

  2. Autecology of broadleaved species

    OpenAIRE

    Gonin, Pierre; Larrieu, Laurent; Coello, Jaime; Marty, Pauline; Lestrade , Marine; Becquey, Jacques; Claessens, Hugues

    2013-01-01

    Anyone involved in timber production needs some knowledge of autecology. With the renewed interest in hardwoods in the last 20 years, they are increasingly being introduced by planting or encouraged in natural stands. The results in terms of growth have not always met foresters’ expectations, due to technical problems and especially because the species are not always suited to the different sites. While the principle of establishing hardwoods is not in question, it is important to be aware of...

  3. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

  4. Confronting species distribution model predictions with species functional traits.

    Science.gov (United States)

    Wittmann, Marion E; Barnes, Matthew A; Jerde, Christopher L; Jones, Lisa A; Lodge, David M

    2016-02-01

    Species distribution models are valuable tools in studies of biogeography, ecology, and climate change and have been used to inform conservation and ecosystem management. However, species distribution models typically incorporate only climatic variables and species presence data. Model development or validation rarely considers functional components of species traits or other types of biological data. We implemented a species distribution model (Maxent) to predict global climate habitat suitability for Grass Carp (Ctenopharyngodon idella). We then tested the relationship between the degree of climate habitat suitability predicted by Maxent and the individual growth rates of both wild (N = 17) and stocked (N = 51) Grass Carp populations using correlation analysis. The Grass Carp Maxent model accurately reflected the global occurrence data (AUC = 0.904). Observations of Grass Carp growth rate covered six continents and ranged from 0.19 to 20.1 g day(-1). Species distribution model predictions were correlated (r = 0.5, 95% CI (0.03, 0.79)) with observed growth rates for wild Grass Carp populations but were not correlated (r = -0.26, 95% CI (-0.5, 0.012)) with stocked populations. Further, a review of the literature indicates that the few studies for other species that have previously assessed the relationship between the degree of predicted climate habitat suitability and species functional traits have also discovered significant relationships. Thus, species distribution models may provide inferences beyond just where a species may occur, providing a useful tool to understand the linkage between species distributions and underlying biological mechanisms.

  5. Delayed growth

    Science.gov (United States)

    ... Slow rate of growth; Retarded growth and development; Growth delay Images Toddler development References Cooke DW, Divall SA, Radovick S. Normal and aberrant growth in children. In: Melmed S, Polonsky KS, Larsen PR, ...

  6. Catalase and superoxide dismutase conjugated with platelet-endothelial cell adhesion molecule antibody distinctly alleviate abnormal endothelial permeability caused by exogenous reactive oxygen species and vascular endothelial growth factor.

    Science.gov (United States)

    Han, Jingyan; Shuvaev, Vladimir V; Muzykantov, Vladimir R

    2011-07-01

    Reactive oxygen species (ROS) superoxide anion (O(2)()) and hydrogen peroxide (H(2)O(2)) produced by activated leukocytes and endothelial cells in sites of inflammation or ischemia cause endothelial barrier dysfunction that may lead to tissue edema. Antioxidant enzymes (AOEs) catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet-endothelial cell adhesion molecule-1 (PECAM-1) specifically bind to endothelium, quench the corresponding ROS, and alleviate vascular oxidative stress and inflammation. In the present work, we studied the effects of anti-PECAM/catalase and anti-PECAM/SOD conjugates on the abnormal permeability manifested by transendothelial electrical resistance decline, increased fluorescein isothiocyanate-dextran influx, and redistribution of vascular endothelial-cadherin in human umbilical vein endothelial cell (HUVEC) monolayers. Anti-PECAM/catalase protected HUVEC monolayers against H(2)O(2)-induced endothelial barrier dysfunction. Polyethylene glycol-conjugated catalase exerted orders of magnitude lower endothelial uptake and no protective effect, similarly to IgG/catalase. Anti-PECAM/catalase, but not anti-PECAM/SOD, alleviated endothelial hyperpermeability caused by exposure to hypoxanthine/xanthine oxidase, implicating primarily H(2)O(2) in the disruption of the endothelial barrier in this model. Thrombin-induced endothelial permeability was not affected by treatment with anti-PECAM/AOEs or the NADPH oxidase inhibitor apocynin or overexpression of AOEs, indicating that the endogenous ROS play no key role in thrombin-mediated endothelial barrier dysfunction. In contrast, anti-PECAM/SOD, but not anti-PECAM/catalase, inhibited a vascular endothelial growth factor (VEGF)-induced increase in endothelial permeability, identifying a key role of endogenous O(2)() in the VEGF-mediated regulation of endothelial barrier function. Therefore, AOEs targeted to endothelial cells provide versatile molecular tools for testing the roles of

  7. The inhibitory effect of CIL-102 on the growth of human astrocytoma cells is mediated by the generation of reactive oxygen species and induction of ERK1/2 MAPK

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Chih-Chuan [Institut