WorldWideScience

Sample records for aspen populus tremuloides

  1. Transcriptome characterization and detection of gene expression differences in aspen (Populus tremuloides)

    Science.gov (United States)

    Hardeep S. Rai; Karen E. Mock; Bryce A. Richardson; Richard C. Cronn; Katherine J. Hayden; Jessica W. Wright; Brian J. Knaus; Paul G. Wolf

    2013-01-01

    Aspen (Populus tremuloides) is a temperate North American tree species with a geographical distribution more extensive than any other tree species on the continent. Because it is economically important for pulp and paper industries and ecologically important for its role as a foundation species in forest ecosystems, the decline of aspen in large...

  2. Influence of climate on the growth of quaking aspen (Populus tremuloides) in Colorado and southern Wyoming

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    M. M. Dudley; Jose Negron; N. A. Tisserat; W. D. Shepperd; W. R. Jacobi

    2015-01-01

    We analyzed a series of increment cores collected from 260 adult dominant or co-dominant quaking aspen (Populus tremuloides Michx.) trees from national forests across Colorado and southern Wyoming in 2009 and 2010. Half of the cores were collected from trees in stands with a high amount of crown dieback, and half were from lightly damaged stands. We define the level of...

  3. Plant Community Chemical Composition Influences Trembling Aspen (Populus tremuloides) Intake by Sheep.

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    Heroy, Kristen Y; St Clair, Samuel B; Burritt, Elizabeth A; Villalba, Juan J

    2017-08-01

    Nutrients and plant secondary compounds in aspen (Populus tremuloides) may interact with nutrients in the surrounding vegetation to influence aspen use by herbivores. Thus, this study aimed to determine aspen intake and preference by sheep in response to supplementary nutrients or plant secondary compounds (PSC) present in aspen trees. Thirty-two lambs were randomly assigned to one of four molasses-based supplementary feeds to a basal diet of tall fescue hay (N = 8) during three experiments. The supplements were as follows: (1) high-protein (60% canola meal), (2) a PSC (6% quebracho tannins), (3) 25% aspen bark, and (4) control (100% molasses). Supplements were fed from 0700 to 0900, then lambs were fed fresh aspen leaves collected from stands containing high (Experiment 1, 2) or low (Experiment 3) concentrations of phenolic glycosides (PG). In Experiment 2, lambs were simultaneously offered aspen, a forb (Lathyrus pauciflorus), and a grass (Bromus inermis) collected from the aspen understory. Animals supplemented with high protein or tannins showed greater intake of aspen leaves than animals supplemented with bark or the control diet (P plant community influence aspen use by herbivores.

  4. A review of the potential effects of climate change on quaking aspen (Populus tremuloides) in the Western United States and a new tool for surveying sudden aspen decline

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    Toni Lyn Morelli; Susan C. Carr

    2011-01-01

    We conducted a literature review of the effects of climate on the distribution and growth of quaking aspen (Populus tremuloides Michx.) in the Western United States. Based on our review, we summarize models of historical climate determinants of contemporary aspen distribution. Most quantitative climate-based models linked aspen presence and growth...

  5. Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA

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    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

    2003-01-01

    We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

  6. Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States

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    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2015-01-01

    Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as competition, or functional traits, such as allometry. To assess the role of disease in mediating mortality risk in quaking aspen (Populus tremuloides), we developed hierarchical Bayesian models for both disease prevalence in live aspen stems and the resulting survival rates of healthy and diseased aspen near the species' southern range limit using 5088 individual trees on 281 United States Forest Service Forest Inventory and Analysis plots in the southwestern United States.

  7. Elevated Rocky Mountain elk numbers prevent positive effects of fire on quaking aspen (Populus tremuloides) recruitment

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    Smith, David Solance; Fettig, Stephen M.; Bowker, Matthew A.

    2016-01-01

    Quaking aspen (Populus tremuloides) is the most widespread tree species in North America and has supported a unique ecosystem for tens of thousands of years, yet is currently threatened by dramatic loss and possible local extinctions. While multiple factors such as climate change and fire suppression are thought to contribute to aspen’s decline, increased browsing by elk (Cervus elaphus), which have experienced dramatic population increases in the last ∼80 years, may severely inhibit aspen growth and regeneration. Fires are known to favor aspen recovery, but in the last several decades the spatial scale and intensity of wildfires has greatly increased, with poorly understood ramifications for aspen growth. Here, focusing on the 2000 Cerro Grande fire in central New Mexico – one of the earliest fires described as a “mega-fire” - we use three methods to examine the impact of elk browsing on aspen regeneration after a mega-fire. First, we use an exclosure experiment to show that aspen growing in the absence of elk were 3× taller than trees growing in the presence of elk. Further, aspen that were both protected from elk and experienced burning were 8.5× taller than unburned trees growing in the presence of elk, suggesting that the combination of release from herbivores and stimulation from fire creates the largest aspen growth rates. Second, using surveys at the landscape level, we found a correlation between elk browsing intensity and aspen height, such that where elk browsing was highest, aspen were shortest. This relationship between elk browsing intensity and aspen height was stronger in burned (r = −0.53) compared to unburned (r = −0.24) areas. Third, in conjunction with the landscape-level surveys, we identified possible natural refugia, microsites containing downed logs, shrubs etc. that may inhibit elk browsing by physically blocking aspen from elk or by impeding elk’s ability to move through the forest patch. We did not find any

  8. Phenology and climate relationships in aspen (Populus tremuloides Michx.) forest and woodland communities of southwestern Colorado

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    Meier, Gretchen A.; Brown, Jesslyn F.; Evelsizer, Ross J.; Vogelmann, James E.

    2014-01-01

    Trembling aspen (Populus tremuloides Michx.) occurs over wide geographical, latitudinal, elevational, and environmental gradients, making it a favorable candidate for a study of phenology and climate relationships. Aspen forests and woodlands provide numerous ecosystem services, such as high primary productivity and biodiversity, retention and storage of environmental variables (precipitation, temperature, snow–water equivalent) that affect the spring and fall phenology of the aspen woodland communities of southwestern Colorado. We assessed the land surface phenology of aspen woodlands using two phenology indices, start of season time (SOST) and end of season time (EOST), from the U.S. Geological Survey (USGS) database of conterminous U.S. phenological indicators over an 11-year time period (2001–2011). These indicators were developed with 250 m resolution remotely sensed data from the Moderate Resolution Imaging Spectroradiometer processed to highlight vegetation response. We compiled data on SOST, EOST, elevation, precipitation, air temperature, and snow water equivalent (SWE) for selected sites having more than 80% cover by aspen woodland communities. In the 11-year time frame of our study, EOST had significant positive correlation with minimum fall temperature and significant negative correlation with fall precipitation. SOST had a significant positive correlation with spring SWE and spring maximum temperature.

  9. Decay of aspen (Populus tremuloides Michx.) wood in moist and dry boreal, temperate, and tropical forest fragments

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    Grizelle Gonzalez; William Gould; Andrew T. Hudak; Teresa Nettleton Hollingsworth

    2008-01-01

    In this study, we set up a wood decomposition experiment to i) quantify the percent of mass remaining, decay constant and performance strength of aspen stakes (Populus tremuloides) in dry and moist boreal (Alaska and Minnesota, USA), temperate (Washington and Idaho, USA), and tropical (Puerto Rico) forest types, and ii) determine the effects of...

  10. Hebeloma crustuliniforme facilitates ammonium and nitrate assimilation in trembling aspen (Populus tremuloides) seedlings.

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    Siemens, J Aurea; Calvo-Polanco, Mónica; Zwiazek, Janusz J

    2011-11-01

    This study examined the role of ectomycorrhizal associations in nitrogen assimilation of Populus tremuloides seedlings. Seedlings were inoculated with Hebeloma crustuliniforme and compared with non-inoculated plants. Nitrogen-metabolizing enzymatic properties were also determined in H. crustuliniforme grown in sterile culture. The seedlings and fungal cultures were subjected to nitrogen treatments (including NO₃⁻, NH₄⁺ and a combination of NO₃⁻ + NH₄⁺) for 2 months to examine the effects on growth, nitrogen-assimilating enzyme activities and xylem sap concentrations of NH₄⁺ and NO₃⁻. Seedlings were also provided for 3 days with ¹⁵N-labeled NH₄⁺ and NO₃⁻, and leaf and root ¹⁵N content relative to total nitrogen was measured. Both NO₃⁻ and NH₄⁺ were effective in supporting seedling growth when either form was provided separately. When NO₃⁻ and NH₄⁺ were provided together, seedling growth decreased while enzymatic assimilation of NH₄⁺ increased. Additionally, nitrogen assimilation in inoculated seedlings was less affected by the form of nitrogen compared with non-inoculated plants. Fungal ability to enzymatically respond to and assimilate NH₄⁺ combined with aspen's enzymatic responsiveness to NO₃⁻ was likely the reason for efficient assimilation of both nitrogen forms by mycorrhizal plants.

  11. Successful hybridisation of normally incompatible hybrid aspen (Populus tremula × P. tremuloides) and eastern cottonwood (P. deltoides).

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    Liesebach, Heike; Naujoks, Gisela; Ewald, Dietrich

    2011-09-01

    Hybrid aspen (Populus tremula × P. tremuloides) belong to the section Populus. Eastern cottonwood (P. deltoides) is a member of the section Aigeiros within the genus Populus. These poplar sections are generally considered to be incompatible. Here, we describe successful hybridisation between these parents, producing an offspring family with 27 individuals. The hybrid character of individuals was proven by genotypes at 16 nuclear microsatellite loci. One individual was suspected to have more than the diploid chromosome number of 2n = 38 due to the observation of more than two alleles at several loci. This individual is a triploid, ascertained by flow cytometry. Two distinct growth classes of tall and dwarf plants were observed in the progeny, reflecting different degrees of postzygotic incompatibility. Two loci linked to the tested microsatellites have an effect on height growth. Some fast-growing individuals were micropropagated to test them for biomass performance together with other clones in field trials.

  12. Hydraulic conductivity and aquaporin transcription in roots of trembling aspen (Populus tremuloides) seedlings colonized by Laccaria bicolor.

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    Xu, Hao; Cooke, Janice E K; Kemppainen, Minna; Pardo, Alejandro G; Zwiazek, Janusz J

    2016-07-01

    Ectomycorrhizal fungi have been reported to increase root hydraulic conductivity (L pr) by altering apoplastic and plasma membrane intrinsic protein (PIP)-mediated cell-to-cell water transport pathways in associated roots, or to have little effect on root water transport, depending on the interacting species and imposed stresses. In this study, we investigated the water transport properties and PIP transcription in roots of aspen (Populus tremuloides) seedlings colonized by the wild-type strain of Laccaria bicolor and by strains overexpressing a major fungal water-transporting aquaporin JQ585595. Inoculation of aspen seedlings with L. bicolor resulted in about 30 % colonization rate of root tips, which developed dense mantle and the Hartig net that was restricted in the modified root epidermis. Transcript abundance of the aspen aquaporins PIP1;2, PIP2;1, and PIP2;2 decreased in colonized root tips. Root colonization by JQ585595-overexpressing strains had no significant impact on seedling shoot water potentials, gas exchange, or dry mass; however, it led to further decrease in transcript abundance of PIP1;2 and PIP2;3 and the significantly lower L pr than in non-inoculated roots. These results, taken together with our previous study that showed enhanced root water hydraulics of L. bicolor-colonized white spruce (Picea glauca), suggest that the impact of L. bicolor on root hydraulics varies by the ectomycorrhiza-associated tree species.

  13. Impacts of Climate and Insect Defoliators on Trembling Aspen (Populus tremuloides) Mortality and Productivity in Alaskan Boreal Forests

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    Boyd, M. A.; Goetz, S. J.; Rogers, B. M.; Walker, X. J.; Mack, M. C.

    2016-12-01

    Unprecedented rates of climate change have increased tree mortality and growth decline in forested ecosystems worldwide. The boreal forest has experienced a temperature increase of approximately 1.5 º C since 1970, a trend which is expected to continue. In response to the warming and drying of the boreal forest trembling aspen (Populus tremuloides) has experienced recent large-scale die-back. Although die-back is thought to be primarily a result of direct climate changes, insect infestation is another possible driver of aspen mortality and may interact strongly with recent climate. Throughout interior Alaska widespread and consistent foliar damage by the aspen epidermal leaf miner Phyllocnistis populiella has been observed concurrent with some of the warmest and driest growing seasons on record. Here we use tree ring width measurements, tree ring stable carbon isotope signatures, and forest inventory data to study the influence of leaf miner and climate on aspen mortality and productivity decline in the Alaskan boreal forest. In the summer of 2016 we sampled eight Cooperative Alaska Forest Inventory (CAFI) sites established by the US Forest Service in 1994. Since establishment tree status and infestation were recorded every 5 years. Each sampled site was aspen dominated and mortality ranged from 3.5% to 8% within a 5-year sampling period. We collected a total of 24 aspen tree cores and disks from each site: 12 from dead trees and 12 from live trees. In order to assess the influence of leaf miner on radial growth and tree ring stable carbon isotope ratios, cores were also collected from aspen stands surrounding Fairbanks where the size and severity of leaf miner infestation has been recorded since 2003. We expect that prior to mortality trees will show a decline in growth that is correlated to moisture stress and leaf miner infestation. We also expect to see an enriched carbon isotope signal as a result of infestation that will be decoupled from moisture, the

  14. Factors affecting fall down rates of dead aspen (Populus tremuloides) biomass following severe drought in west-central Canada.

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    Ted Hogg, Edward H; Michaelian, Michael

    2015-05-01

    Increases in mortality of trembling aspen (Populus tremuloides Michx.) have been recorded across large areas of western North America following recent periods of exceptionally severe drought. The resultant increase in standing, dead tree biomass represents a significant potential source of carbon emissions to the atmosphere, but the timing of emissions is partially driven by dead-wood dynamics which include the fall down and breakage of dead aspen stems. The rate at which dead trees fall to the ground also strongly influences the period over which forest dieback episodes can be detected by aerial surveys or satellite remote sensing observations. Over a 12-year period (2000-2012), we monitored the annual status of 1010 aspen trees that died during and following a severe regional drought within 25 study areas across west-central Canada. Observations of stem fall down and breakage (snapping) were used to estimate woody biomass transfer from standing to downed dead wood as a function of years since tree death. For the region as a whole, we estimated that >80% of standing dead aspen biomass had fallen after 10 years. Overall, the rate of fall down was minimal during the year following stem death, but thereafter fall rates followed a negative exponential equation with k = 0.20 per year. However, there was high between-site variation in the rate of fall down (k = 0.08-0.37 per year). The analysis showed that fall down rates were positively correlated with stand age, site windiness, and the incidence of decay fungi (Phellinus tremulae (Bond.) Bond. and Boris.) and wood-boring insects. These factors are thus likely to influence the rate of carbon emissions from dead trees following periods of climate-related forest die-off episodes. © 2014 Her Majesty the Queen in Right of Canada Global Change Biology © 2014 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Natural Resources Canada.

  15. Influence of Genotype, Environment, and Gypsy Moth Herbivory on Local and Systemic Chemical Defenses in Trembling Aspen (Populus tremuloides).

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    Rubert-Nason, Kennedy F; Couture, John J; Major, Ian T; Constabel, C Peter; Lindroth, Richard L

    2015-07-01

    Numerous studies have explored the impacts of intraspecific genetic variation and environment on the induction of plant chemical defenses by herbivory. Relatively few, however, have considered how those factors affect within-plant distribution of induced defenses. This work examined the impacts of plant genotype and soil nutrients on the local and systemic phytochemical responses of trembling aspen (Populus tremuloides) to defoliation by gypsy moth (Lymantria dispar). We deployed larvae onto foliage on individual tree branches for 15 days and then measured chemistry in leaves from: 1) branches receiving damage, 2) undamaged branches of insect-damaged trees, and 3) branches of undamaged control trees. The relationship between post-herbivory phytochemical variation and insect performance also was examined. Plant genotype, soil nutrients, and damage all influenced phytochemistry, with genotype and soil nutrients being stronger determinants than damage. Generally, insect damage decreased foliar nitrogen, increased levels of salicinoids and condensed tannins, but had little effect on levels of a Kunitz trypsin inhibitor, TI3. The largest damage-mediated tannin increases occurred in leaves on branches receiving damage, whereas the largest salicinoid increases occurred in leaves of adjacent, undamaged branches. Foliar nitrogen and the salicinoid tremulacin had the strongest positive and negative relationships, respectively, with insect growth. Overall, plant genetics and environment concomitantly influenced both local and systemic phytochemical responses to herbivory. These findings suggest that herbivory can contribute to phytochemical heterogeneity in aspen foliage, which may in turn influence future patterns of herbivory and nutrient cycling over larger spatial scales.

  16. Elevated growth temperatures alter hydraulic characteristics in trembling aspen (Populus tremuloides) seedlings: implications for tree drought tolerance

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    Danielle A. Way; Jean-Christophe Domec; Robert B. Jackson

    2013-01-01

    Although climate change will alter both soil water availability and evaporative demand, our understanding of how future climate conditions will alter tree hydraulic architecture is limited. Here, we demonstrate that growth at elevated temperatures (ambient +5 °C) affects hydraulic traits in seedlings of the deciduous boreal tree species Populus tremuloides, with the...

  17. Rapid mortality of Populus tremuloides in southwestern Colorado, USA

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    James J. Worrall; Leanne Egeland; Thomas Eager; Roy A. Mask; Erik W. Johnson; Philip A. Kemp; Wayne D. Shepperd

    2008-01-01

    Concentrated patches of recent trembling aspen (Populus tremuloides) mortality covered 56,091 ha of Colorado forests in 2006. Mortality has progressed rapidly. Area affected increased 58% between 2005 and 2006 on the Mancos-Dolores Ranger District, San Juan National Forest, where it equaled nearly 10% of the aspen cover type. In four stands that were...

  18. Effects of Elevated Atmospheric Carbon Dioxide and Tropospheric Ozone on Phytochemical Composition of Trembling Aspen ( Populus tremuloides ) and Paper Birch ( Betula papyrifera ).

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    Couture, John J; Meehan, Timothy D; Rubert-Nason, Kennedy F; Lindroth, Richard L

    2017-01-01

    Anthropogenic activities are altering levels of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3). These changes can alter phytochemistry, and in turn, influence ecosystem processes. We assessed the individual and combined effects of elevated CO2 and O3 on the phytochemical composition of two tree species common to early successional, northern temperate forests. Trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) were grown at the Aspen FACE (Free-Air Carbon dioxide and ozone Enrichment) facility under four combinations of ambient and elevated CO2 and O3. We measured, over three years (2006-08), the effects of CO2 and O3 on a suite of foliar traits known to influence forest functioning. Elevated CO2 had minimal effect on foliar nitrogen and carbohydrate levels in either tree species, and increased synthesis of condensed tannins and fiber in aspen, but not birch. Elevated O3 decreased nitrogen levels in both tree species and increased production of sugar, condensed tannins, fiber, and lignin in aspen, but not birch. The magnitude of responses to elevated CO2 and O3 varied seasonally for both tree species. When co-occurring, CO2 offset most of the changes in foliar chemistry expressed under elevated O3 alone. Our results suggest that levels of CO2 and O3 predicted for the mid-twenty-first century will alter the foliar chemistry of northern temperate forests with likely consequences for forest community and ecosystem dynamics.

  19. The impact of vessel size on vulnerability curves: data and models for within-species variability in saplings of aspen, Populus tremuloides Michx.

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    Cai, Jing; Tyree, Melvin T

    2010-07-01

    The objective of this study was to quantify the relationship between vulnerability to cavitation and vessel diameter within a species. We measured vulnerability curves (VCs: percentage loss hydraulic conductivity versus tension) in aspen stems and measured vessel-size distributions. Measurements were done on seed-grown, 4-month-old aspen (Populus tremuloides Michx) grown in a greenhouse. VCs of stem segments were measured using a centrifuge technique and by a staining technique that allowed a VC to be constructed based on vessel diameter size-classes (D). Vessel-based VCs were also fitted to Weibull cumulative distribution functions (CDF), which provided best-fit values of Weibull CDF constants (c and b) and P(50) = the tension causing 50% loss of hydraulic conductivity. We show that P(50) = 6.166D(-0.3134) (R(2) = 0.995) and that b and 1/c are both linear functions of D with R(2) > 0.95. The results are discussed in terms of models of VCs based on vessel D size-classes and in terms of concepts such as the 'pit area hypothesis' and vessel pathway redundancy.

  20. PHYTOALEXIN DEFICIENT 4 affects reactive oxygen species metabolism, cell wall and wood properties in hybrid aspen (Populus tremula L. × tremuloides).

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    Ślesak, Ireneusz; Szechyńska-Hebda, Magdalena; Fedak, Halina; Sidoruk, Natalia; Dąbrowska-Bronk, Joanna; Witoń, Damian; Rusaczonek, Anna; Antczak, Andrzej; Drożdżek, Michał; Karpińska, Barbara; Karpiński, Stanisław

    2015-07-01

    The phytoalexin deficient 4 (PAD4) gene in Arabidopsis thaliana (AtPAD4) is involved in the regulation of plant--pathogen interactions. The role of PAD4 in woody plants is not known; therefore, we characterized its function in hybrid aspen and its role in reactive oxygen species (ROS)-dependent signalling and wood development. Three independent transgenic lines with different suppression levels of poplar PAD expression were generated. All these lines displayed deregulated ROS metabolism, which was manifested by an increased H2O2 level in the leaves and shoots, and higher activities of manganese superoxide dismutase (MnSOD) and catalase (CAT) in the leaves in comparison to the wild-type plants. However, no changes in non-photochemical quenching (NPQ) between the transgenic lines and wild type were observed in the leaves. Moreover, changes in the ROS metabolism in the pad4 transgenic lines positively correlated with wood formation. A higher rate of cell division, decreased tracheid average size and numbers, and increased cell wall thickness were observed. The results presented here suggest that the Populus tremula × tremuloides PAD gene might be involved in the regulation of cellular ROS homeostasis and in the cell division--cell death balance that is associated with wood development. © 2014 John Wiley & Sons Ltd.

  1. Intraspecific variation in root and leaf traits and leaf-root trait linkages in eight aspen demes (Populus tremula and P. tremuloides

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    Peter eHajek

    2013-10-01

    Full Text Available Leaf and fine root morphology and physiology have been found to vary considerably among tree species, but not much is known about intraspecific variation in root traits and their relatedness to leaf traits. Various aspen progenies (Populus tremula and P. tremuloides with different growth performance are used in short-rotation forestry. Hence, a better understanding of the link between root trait syndromes and the adaptation of a deme to a particular environment is essential in order to improve the match between planted varieties and their growth conditions. We examined the between-deme (genetic and within-deme (mostly environmental variation in important fine root traits [mean root diameter, specific root area (SRA and specific root length (SRL, root tissue density (RTD, root tip abundance, root N concentration] and their co-variation with leaf traits [specific leaf area (SLA, leaf size, leaf N concentration] in eight genetically distinct P. tremula and P. tremuloides demes. Five of the six root traits varied significantly between the demes with largest genotypic variation in root tip abundance and lowest in mean root diameter and RTD (no significant difference. Within-deme variation in root morphology was as large as between-deme variation suggesting a relatively low genetic control. Significant relationships existed neither between SLA and SRA nor between leaf N and root N concentration in a plant. Contrary to expectation, high aboveground relative growth rates (RGR were associated with large, and not small, fine root diameters with low SRA and SRL. Compared to leaf traits, the influence of root traits on RGR was generally low. We conclude that aspen exhibits large intraspecific variation in leaf and also in root morphological traits which is only partly explained by genetic distances. A root order-related analysis might give deeper insights into intraspecific root trait variation.

  2. Conifer Recruitment in Trembling Aspen (Populus Tremuloides Michx. Stands along an East-West Gradient in the Boreal Mixedwoods of Canada

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    Pierre Nlungu-Kweta

    2014-11-01

    Full Text Available Ongoing climate change is likely to result in shifts in successional dynamics in boreal mixedwood stands. Using data from provincial forest inventory databases, we examined the occurrence and abundance of the regeneration of various coniferous species (white spruce, black spruce and balsam fir along an east-west Canadian gradient in aspen-dominated stands. The interpretation of the results was based on environmental conditions, including climate, natural fire regime and human impacts. We found that conifer regeneration was present in aspen stands along the entire gradient, despite differences in climatic conditions and fire regimes between the west (warmer and drier, with large recurrent fires and east (more humid with relatively long fire cycles. However, abundance and distribution varied from one conifer species to the next. The abundance of white spruce decreased towards the eastern end of the longitudinal gradient, while balsam fir and black spruce abundance decreased towards the west. Although abundance decreased, balsam fir and black spruce regeneration was still present in western Canada. This study shows that it is difficult to interpret the effects of climate change on conifer recruitment without accounting for the superimposed effects of human activities.

  3. The responses of Vitreoscilla hemoglobin-expressing hybrid aspen (Populus tremula × tremuloides) exposed to 24-h herbivory: expression of hemoglobin and stress-related genes in exposed and nonorthostichous leaves.

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    Sutela, Suvi; Ylioja, Tiina; Jokipii-Lukkari, Soile; Anttila, Anna-Kaisa; Julkunen-Tiitto, Riitta; Niemi, Karoliina; Mölläri, Tiina; Kallio, Pauli T; Häggman, Hely

    2013-11-01

    The responses of transcriptome and phenolic compounds were determined with Populus tremula L. × Populus tremuloides Michx. expressing the hemoglobin (Hb) of Vitreoscilla (VHb) and non-transformant (wt) line. After 24-h exposure of leaves to Conistra vaccinii L., the transcript levels of endogenous non-symbiotic class 1 Hb (PttHb1) and truncated Hb (PttTrHb) genes were modestly reduced and increased, respectively, in both wt and VHb-expressing line. Besides the herbivory exposed leaves showing the most significant transcriptome changes, alterations were also detected in the transcriptome of nonorthostichous leaves positioned directly above the exposed leaves. Both wt and VHb-expressing line displayed similar herbivory-induced effects on gene expression, although the extent of responses was more pronounced in the wt than in the VHb-expressing line. The contents of phenolic compounds were not altered due to herbivory and they were alike in the wt and VHb-expressing line. In addition, we determined the relative growth rates (RGRs) of Orthosia gothica L., Ectropis crepuscularia Denis & Schiff. and Orgyia antiqua L. larvae, and found no variation in the RGRs between the lines. Thus, VHb-expressing P. tremula × tremuloides lines showed to be comparable with wt in regards to the food quality of leaves.

  4. Stem wood properties of Populus tremuloides, Betula papyrifera and Acer saccharum saplings after three years of treatments to elevated carbon dioxide and ozone

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    Seija Kaakinen; Katri Kostiainen; Fredrik Ek; Pekka Saranpaa; Mark E. Kubiske; Jaak Sober; David F. Karnosky; Elina Vapaavuori

    2004-01-01

    The aim of this study was to examine the effects of elevated carbon dioxide [CO2] and ozone [O3] and their interaction on wood chemistry and anatomy of five clones of 3-year-old trembling aspen (Populus tremuloides Michx.). Wood chemistry was studied also on paper birch (Betula papyrifera...

  5. Transformation of populus tremuloides using agrobacterium rhizogenes

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    Riu, Key Zung; U, Zang Kual; So, In Seop; Lee, Sun Joo; Koh, Young Hwan [Chju National University, Cheju, (Korea, Republic of)

    1994-12-31

    Several factors affecting Arhizogenes-mediated transformation of Populus were studied. The leaf section of Populus was more sensitive to kanamycin used for selection of transformants than the stem section. The soaking period for inoculation did not affect gall formation up to 2 hours. The optimum concentration of acetosydingone and pH of bacterial culture medium for inoculation were 59.mu.M and 5. 5, respectively. One day cocultivation after inoculation gave highest transformation rate. The visible hairy roots were formed from the transformed leaf sections within 3 weeks after culture on both of the media with and without growth regulators. The plantlets were regenerated from the infected leaf sections within 6 weeks after culture on the medium containing 0.005 mg/1 of NAA and 0.5 mg/1 of BA. The expression of the introduced opine genes in the plantlets were confirmed by analysis of agropine and mannopine. (author)

  6. Recovery of Populus tremuloides seedlings following severe drought causing total leaf mortality and extreme stem embolism.

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    Lu, Yanyuan; Equiza, Maria Alejandra; Deng, Xiping; Tyree, Melvin T

    2010-11-01

    In contrast with other native Populus species in North America, Populus tremuloides (aspen) can successfully establish itself in drought-prone areas, yet no comprehensive analysis has been performed on the ability of seedlings to withstand and recover from a severe drought resulting in complete leaf mortality. Here, we subjected 4-month-old aspen seedlings grown in two contrasting soil media to a progressive drought until total leaf mortality, followed by a rewatering cycle. Stomatal conductance (g(s) ), photosynthesis and transpiration followed a sigmoid decline with declining fraction of extractable soil water values. Cessation of leaf expansion occurred close to the end of the linear-decrease phase, when g(s) was reduced by 95%. Leaf mortality started after g(s) reached the lowest values, which corresponded to a stem-xylem pressure potential (Ψ(xp)) of -2.0 MPa and a percent loss of stem hydraulic conductivity (PLC) of 50%. In plants with 50% leaf mortality, PLC values remained around 50%. Complete leaf mortality occurred at an average stem PLC of 90%, but all seedlings were able to resprout after 6-10 days of being rewatered. Plants decapitated at soil level before rewatering developed root suckers, while those left with a 4-cm stump or with their stems intact resprouted exclusively from axillary buds. Resprouting was accompanied by recovery of stem hydraulic conductivity, with PLC values around 30%. The percentage of resprouted buds was negatively correlated with the stem %PLC. Thus, the recovery of stem hydraulic conductivity appears as an important factor in the resprouting capacity of aspen seedlings following a severe drought. Copyright © Physiologia Plantarum 2010.

  7. Assessing aspen using remote sensing

    Science.gov (United States)

    Randy Hamilton; Kevin Megown; Jeff DiBenedetto; Dale Bartos; Anne Mileck

    2009-01-01

    Large areas of aspen (Populus tremuloides) have disappeared and continue to disappear from western forests due to successional decline and sudden aspen decline (SAD). This loss of aspen ecosystems negatively impacts watersheds, wildlife, plants, and recreation. Much can still be done to restore aspen if timely and appropriate action is taken. However, land managers...

  8. Impacts of greenhouse gases on epicuticular waxes of Populus tremuloides Michx.: Results from an open-air exposure and a natural O{sub 3} gradient

    Energy Technology Data Exchange (ETDEWEB)

    Mankovska, B. [Forest Research Institute, T.G. Masaryka Street 22, 960 92 Zvolen (Slovakia); Percy, K.E. [Canadian Forest Service, Fredericton (Canada); Karnosky, D.F. [Michigan Technological University, Houghton, MI (United States)]. E-mail: karnosky@mtu.edu

    2005-10-15

    Epicuticular waxes of three trembling aspen (Populus tremuloides Michx.) clones differing in O{sub 3} tolerance were examined over six growing seasons (1998-2003) at three bioindicator sites in the Lake States region of the USA and at FACTS II (Aspen FACE) site in Rhinelander, WI. Differences in epicuticular wax structure were determined by scanning electron microscopy and quantified by a coefficient of occlusion. Statistically significant increases in stomatal occlusion occurred for the three O{sub 3} bioindicator sites, with the higher O{sub 3} sites having the most affected stomata for all three clones as well as for all treatments including elevated CO{sub 2}, elevated O{sub 3}, and elevated CO{sub 2}+O{sub 3}. We recorded statistically significant differences between aspen clones and between sampling period (spring, summer, fall). We found no statistically significant differences between treatments or aspen clones in stomatal frequency. - Structure of epicuticular waxes indicated phytotoxic effects of greenhouse gases on Populus tremuloides Michx.

  9. Slow lifelong growth predisposes Populus tremuloides to tree mortality

    Science.gov (United States)

    Kathryn B. Ireland; Margaret M. Moore; Peter Z. Fule; Thomas J. Zegler; Robert E. Keane

    2014-01-01

    Widespread dieback of aspen forests, sometimes called sudden aspen decline, has been observed throughout much of western North America, with the highest mortality rates in the southwestern United States. Recent aspen mortality has been linked to drought stress and elevated temperatures characteristic of conditions expected under climate change, but the role of...

  10. Management of aspen plant communities on the National Elk Refuge, Wyoming

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — There are 1,860 acres (753 ha) of aspen (Populus tremuloides) plant communities on the National Elk Refuge (NER). Aspen is an important tree species on the Refuge,...

  11. Wood property variation in Populus

    Science.gov (United States)

    Dean W. Einspahr; Miles K. Benson; John R. Peckham

    1968-01-01

    The use of bigtooth aspen (Populus grandidentata Michx.), quaking aspen (P. tremuloides Michx.), and cottonwood (P. deltoides Bartr.) by the pulp and paper industry has increased greatly during the past decade. This expanded use has stimulated research on the genetic improvement of Populus. For the past 12 years...

  12. Landscape composition in aspen woodlands under various modeled fire regimes

    Science.gov (United States)

    Eva K. Strand; Stephen C. Bunting; Lee A. Vierling

    2012-01-01

    Quaking aspen (Populus tremuloides) is declining across the western United States. Aspen habitats are diverse plant communities in this region and loss of these habitats can cause shifts in biodiversity, productivity, and hydrology across spatial scales. Western aspen occurs on the majority of sites seral to conifer species, and long-term maintenance of these aspen...

  13. Growth and photosynthesis of plants in response to environmental stress. [Raphanus sativus; Glycine max; Salix nigra; Alnus serrulata; Populus tremuloides

    Energy Technology Data Exchange (ETDEWEB)

    Greitner, C.S.

    1991-01-01

    Environmental stresses generally decrease photosynthetic rates and growth of plants, and alter biomass partitioning. Nutrient deficiency and drought cause root:shoot ratios to increase, whereas the air pollutant ozone (O[sub 3]) causes an opposite shift in carbon allocation. Plants in nature usually grow under suboptimal conditions; therefore plants were raised with O[sub 3] combined with other stresses to analyze the mechanisms whereby multiple stresses influence gas exchange and growth. Physiological and growth responses to stress were determined for radish (raphanus sativus), soybean (Glycine max) willow (Salix nigra), alder (Alnus serrulata) and aspen (Populus tremuloides) in laboratory and field trials. In willow, high-nutrient status plants had more visible injury, but a smaller decline in leaf area with O[sub 3] than did low-nutrient plants. Ultrastructure of host plant cells in alder root nodules was disrupted by O[sub 3], suggesting that this air pollutant can affect the ability of plants to acquire nutrients via symbiosis. Biomass and root:shoot ratios decreased with O[sub 3] in radish and soy-bean. Shifts in stable carbon isotope ratios were caused by O[sub 3], and this technique was used to integrate the effects of O[sub 3] on gas exchange over time. In aspen, O[sub 3] enhanced photosynthesis and foliar areas in young leaves of well-watered aspen, partially compensating for declines in older leaves. This effect was more pronounced in plants raised at a high nitrogen level than in N-deficient plants. Carboxylation efficiency decreased in older, but increased in younger leaves with O[sub 3]. Prior exposure to drought reduced effects of O[sub 3] on photosynthesis and leaf area.

  14. Glycosylation-mediated phenylpropanoid partitioning in Populus tremuloides cell cultures

    Directory of Open Access Journals (Sweden)

    Babst Benjamin A

    2009-12-01

    Full Text Available Abstract Background Phenylpropanoid-derived phenolic glycosides (PGs and condensed tannins (CTs comprise large, multi-purpose non-structural carbon sinks in Populus. A negative correlation between PG and CT concentrations has been observed in several studies. However, the molecular mechanism underlying the relationship is not known. Results Populus cell cultures produce CTs but not PGs under normal conditions. Feeding salicyl alcohol resulted in accumulation of salicins, the simplest PG, in the cells, but not higher-order PGs. Salicin accrual reflected the stimulation of a glycosylation response which altered a number of metabolic activities. We utilized this suspension cell feeding system as a model for analyzing the possible role of glycosylation in regulating the metabolic competition between PG formation, CT synthesis and growth. Cells accumulated salicins in a dose-dependent manner following salicyl alcohol feeding. Higher feeding levels led to a decrease in cellular CT concentrations (at 5 or 10 mM, and a negative effect on cell growth (at 10 mM. The competition between salicin and CT formation was reciprocal, and depended on the metabolic status of the cells. We analyzed gene expression changes between controls and cells fed with 5 mM salicyl alcohol for 48 hr, a time point when salicin accumulation was near maximum and CT synthesis was reduced, with no effect on growth. Several stress-responsive genes were up-regulated, suggestive of a general stress response in the fed cells. Salicyl alcohol feeding also induced expression of genes associated with sucrose catabolism, glycolysis and the Krebs cycle. Transcript levels of phenylalanine ammonia lyase and most of the flavonoid pathway genes were reduced, consistent with down-regulated CT synthesis. Conclusions Exogenous salicyl alcohol was readily glycosylated in Populus cell cultures, a process that altered sugar utilization and phenolic partitioning in the cells. Using this system, we

  15. Aspen biology, community classification, and management in the Blue Mountains

    Science.gov (United States)

    David K. Swanson; Craig L. Schmitt; Diane M. Shirley; Vicky Erickson; Kenneth J. Schuetz; Michael L. Tatum; David C. Powell

    2010-01-01

    Quaking aspen (Populus tremuloides Michx.) is a valuable species that is declining in the Blue Mountains of northeastern Oregon. This publication is a compilation of over 20 years of aspen management experience by USDA Forest Service workers in the Blue Mountains. It includes a summary of aspen biology and occurrence in the Blue Mountains, and a...

  16. Effects of elevated CO2 and ozone on phenolic glycosides of trembling aspen

    Science.gov (United States)

    James K. Nitao; Muraleedharan G. Nair; William J. Mattson; Daniel A. Herms; Bruce A. Birr; Mark D. Coleman; Terry M. Trier; J. G. Isebrands

    1996-01-01

    We tested the effects of elevated CO2 and ozone on concentrations of the phenolic glycosides salicortin and tremulacin in immature and mature foliage of the trembling aspen (Populus tremuloides) clones 216, 259, and 271.

  17. Lichen community change in response to succession in aspen forests of the southern Rocky Mountains

    Science.gov (United States)

    Paul C. Rogers; Ronald J. Ryel

    2008-01-01

    In western North America, quaking aspen (Populus tremuloides) is the most common hardwood in montane landscapes. Fire suppression, grazing and wildlife management practices, and climate patterns of the past century are all potential threats to aspen coverage in this region. If aspen-dependent species are losing habitat, this raises concerns about...

  18. Application of vitrification-derived cryotechniques for long-term storage of poplar and aspen (Populus spp. germplasm

    Directory of Open Access Journals (Sweden)

    I. TSVETKOV

    2008-12-01

    Full Text Available The application of three different vitrification-based freezing strategies for the cryostorage of white poplar (Populus alba L. and hybrid aspen (P. tremula L. × P. tremuloides Michx. have been assessed. The PVS2 vitrification protocol was successfully applied to two white poplar in vitro clones stored for more than 6 months in slow-growth conditions (4 °C, in darkness and showing clear signs of explant etiolation and decay. After 60 min of PVS2 treatment, P. alba L. (cv. Villafranca explants isolated from axillary buds demonstrated significantly better potential for post-freeze regrowth (64% compared to those obtained from apical buds (17%. Similarly, a high level of survival (78% of the frozen hybrid aspen shoot tips was recorded following the application of the same technique. Using the ‘encapsulation-vitrification’ procedure, no toxic effects of the PVS2 treatment were noticed after 120 min exposure, however none of the cryopreserved (poplar and aspen explants survived after 3 weeks. In contrast, the ‘droplet-vitrification’ technique appeared to be very efficient in the cryopreservation of white poplar shoot tips, which increases the opportunities for wider application of this method in other woody species.;

  19. Effect of conifer encroachment into aspen stands on understory biomass

    Science.gov (United States)

    B. R. Stam; J. C. Malechek; D. L. Bartos; J. E. Browns; E. B. Godfrey

    2008-01-01

    Conifers (Picea and Abies spp.) have replaced aspen (Populus tremuloides Michx.) over much of aspen's historic range in the western United States. We measured the impact of this change upon the production of understory vegetation potentially useful as forage for livestock and wildlife on two southern Utah...

  20. Molecular tools and aspen management: A primer and prospectus

    Science.gov (United States)

    Karen E. Mock; Bryce A. Richardson; Paul G. Wolf

    2013-01-01

    Aspen (Populus tremuloides) isaniconic species in North American landscapes, highly valued for recreation, fiber, wildlife and livestock forage, carbon sequestration, biodiversity, and as a fuelbreak. However, there are rising concerns about the ability of aspen to persist in portions of its range, based on bioclimatic modeling, physiological thresholds and mortality...

  1. Hybrid Aspen Response to Shearing in Minnesota: Implications for Biomass Production

    Science.gov (United States)

    Grant M. Domke; Andrew J. David; Anthony W. D' Amato; Alan R. Ek; Gary W. Wycoff

    2011-01-01

    There is great potential for the production of woody biomass feedstocks from hybrid aspen stands; however, little is known about the response of these systems to silvicultural treatments, such as shearing. We sought to address this need by integrating results from more than 20 years of individual tree and yield measurements in hybrid aspen (Populus tremuloides Mich. ×...

  2. The aspen mortality summit; December 18 and 19, 2006; Salt Lake City, UT

    Science.gov (United States)

    Dale L. Bartos; Wayne D. Shepperd

    2010-01-01

    The USDA Forest Service Rocky Mountain Research Station sponsored an aspen summit meeting in Salt Lake City, Utah, on December 18 and19, 2006, to discuss the rapidly increasing mortality of aspen (Populus tremuloides) throughout the western United States. Selected scientists, university faculty, and managers from Federal, State, and non-profit agencies with experience...

  3. A synthetic sex pheromone for the large aspen tortrix in Alaska.

    Science.gov (United States)

    Richard A. Werner; J. Weatherston

    1980-01-01

    Cis-11-tetradecenal was found to be the specific attractant for adult male large aspen tortrix, Choristoneura conflictana (Walker), populations in quaking aspen, Populus tremuloides Michx., forests of interior Alaska. The attractant was dispersed from polyethylene caps in Pherocon® -2 traps placed 1.5 m above ground.

  4. Adaptations of quaking aspen for defense against damage by herbivores and related environmental agents

    Science.gov (United States)

    Richard L. Lindroth

    2001-01-01

    Quaking aspen (Populus tremuloides) employs two major systems of defense against damage by environmental agents: chemical defense and tolerance. Aspen accumulates appreciable quantities of phenolic glycosides (salicylates) and condensed tannins in most tissues and accumulates coniferyl benzoate in flower buds. Phenolic glycosides are toxic and/or deterrent to pathogens...

  5. Ecology, biodiversity, management, and restoration of aspen in the Sierra Nevada

    Science.gov (United States)

    Wayne D. Shepperd; Paul C. Rogers; David Burton; Dale L. Bartos

    2006-01-01

    This report was commissioned by the USDA Forest Service Lake Tahoe Basin Management Unit to synthesize existing information on the ecology and management of aspen (Populus tremuloides) in the Sierra Nevada of California and surrounding environs. It summarizes available information on aspen throughout North America from published literature, internal...

  6. Is the wide distribution of aspen a result of its stress tolerance?

    Science.gov (United States)

    V. J. Lieffers; S. M. Landhausser; E. H. Hogg

    2001-01-01

    Populus tremuloides is distributed from drought-prone fringes of the Great Plains to extremely cold sites at arctic treeline. To occupy these conditions aspen appears to be more tolerant of stress than the other North American species of the genus Populus. Cold winters, cold soil conditions during the growing season, periodic drought, insect defoliation, and...

  7. Photosynthetic acclimation of overstory Populus tremuloides and understory Acer saccharum to elevated atmospheric CO2 concentration: interactions with shade and soil nitrogen

    Science.gov (United States)

    Mark E. Kubiske; Donald R. Zak; Kurt S. Pregitzer; Yu Takeuchi

    2002-01-01

    We exposed Populus tremuloides Michx. and Acer saccharum Marsh. to a factorial combination of ambient and elevated atmospheric CO2 concentrations ([CO2]) and high-nitrogen (N) and low-N soil treatments in open-top chambers for 3 years. Our objective was to compare photosynthetic...

  8. Bioenergy harvest impacts to biodiversity and resilience vary across aspen-dominated forest ecosystems in the Lake States region, USA

    Science.gov (United States)

    Miranda T. Curzon; Anthony W. D' Amato; Brian J. Palik; Kris Verheyen

    2016-01-01

    Questions: Does the increase in disturbance associated with removing harvest residues negatively impact biodiversity and resilience in aspen-dominated forest ecosystems? How do responses of functional diversity measures relate to community recovery and standing biomass? Location: Aspen (Populus tremuloides, Michx.) mixedwood forests in Minnesota...

  9. Moderate-scale mapping methods of aspen stand types: a case study for Cedar Mountain in southern Utah

    Science.gov (United States)

    Chad M. Oukrop; David M. Evans; Dale L. Bartos; R. Douglas Ramsey; Ronald J. Ryel

    2011-01-01

    Quaking aspen (Populus tremuloides Michx.) are the most widely distributed tree species across North America, but its dominance is declining in many areas of the western United States, with certain areas experiencing rapid mortality events over the past decade. The loss of aspen from western landscapes will continue to profoundly impact biological, commercial, and...

  10. Taxonomy Icon Data: quaking aspen [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available png Populus_tremuloides_S.png Populus_tremuloides_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Po...pulus+tremuloides&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Populus+tremuloides&t=NL http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Populus+tremuloides&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Populus+tremuloides&t=NS ...

  11. Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L..

    Directory of Open Access Journals (Sweden)

    Kathryn M Robinson

    Full Text Available We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

  12. Allergic contact dermatitis from salicyl alcohol and salicylaldehyde in aspen bark (Populus tremula).

    Science.gov (United States)

    Aalto-Korte, Kristiina; Välimaa, Jarmo; Henriks-Eckerman, Maj-Len; Jolanki, Riitta

    2005-02-01

    Salicyl alcohol or 2-methylolphenol is a well-known allergen in phenol-formaldehyde resins and a strong sensitizer in guinea pigs. There is 1 previous report of allergic contact dermatitis from salicyl alcohol in aspen bark. We describe a second case with concomitant allergy to salicylaldehyde. An elk researcher who had handled leaves from various trees presented with eczema of the hands, face, flexures, trunk and extremities. Patch testing showed sensitivity to salicyl alcohol, salicylaldehyde, balsam of Peru (Myroxylon pereirae resin), aspen wood dust and an extract prepared from the bark of aspen (Populus tremula). Weaker reactions were observed to bark extracts of rowan (Sorbus aucuparia), tea-leaved willow (Salix phylicifolia) and goat willow (Salix caprea). We analysed salicyl alcohol and salicylaldehyde in the bark extracts and found the 2 chemicals in equal amounts, about 0.9 microg/mg in aspen bark and in lower concentrations in rowan and the willows. We did not find either of the chemicals in the test substance of balsam of Peru (Myroxylon pereirae). Besides salicyl alcohol, salicylaldehyde is also recommended to be used to screen for contact allergy to aspen. Both of these chemicals should be tested in forest workers in areas where aspen is growing.

  13. Historical patterns in lichen communities of montane quaking aspen forests

    Science.gov (United States)

    Paul C. Rogers; Dale L. Bartos; Ronald J. Ryel

    2011-01-01

    Climate shifts and resource exploitation in Rocky Mountain forests have caused profound changes in quaking aspen (Populus tremuloides Michx.) structure and function since Euro-American settlement. It therefore seems likely that commensurate shifts in dependent epiphytes would follow major ecological transitions. In the current study, we merge several lines of inquiry...

  14. Ozone-induced H2O2 accumulation in field-grown aspen and birch is linked to foliar ultrastructure and peroxisomal activity

    Science.gov (United States)

    E. Oksanen; E. Häikiö; J. Sober; D.F. Karnosky

    2003-01-01

    Saplings of three aspen (Populus tremuloides) genotypes and seedlings of paper birch (Betula papyrifera) were exposed to elevated ozone (1.5x ambient) and 560 p.p.m. CO2, singly and in combination, from 1998 at the Aspen-FACE (free-air CO2 enrichment) site (Rhinelander, USA).

  15. Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performance

    Science.gov (United States)

    Leanne M. Vigue; Richard L. Lindroth

    2010-01-01

    Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as...

  16. Effects of canopy-deposition interaction on H{sup +} supply to soils in Pinus banksiana and Populus tremuloides ecosystems in the Athabasca oil sands region in Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kangho, E-mail: kangho@ualberta.ca [Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3 (Canada); Chang, Scott X., E-mail: scott.chang@ualberta.ca [Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3 (Canada); Arshad, M.A., E-mail: charlie.arshad@ales.ualberta.ca [Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3 (Canada); Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, AB, T0H 0C0 (Canada)

    2011-05-15

    Soil acidification has been of concern in the oil sands region in Alberta due to increased acid deposition. Using the canopy budget model, and accounting for H{sup +} canopy leaching by organic acids, we determined sources and sinks of H{sup +} in throughfall in jack pine (Pinus banksiana) and trembling aspen (Populus tremuloides) stands in two watersheds from 2006 to 2009. In pine stands, H{sup +} deposition was greater in throughfall than in bulk precipitation while the opposite was true in aspen stands. The annual H{sup +} interception deposition was 148.8-193.8 and 49.7-70.0 mol{sub c} ha{sup -1} in pine and aspen stands, respectively; while the annual H{sup +} canopy leaching was 127.1-128.7 and 0.0-6.0 mol{sub c} ha{sup -1}, respectively. The greater H{sup +} supply in pine stands was caused by greater interception deposition of SO{sub 4}{sup 2-} and organic acids released from the pine canopy. Such findings have significant implications for establishing critical loads for various ecosystems in the oil sands region. - Highlights: > We monitored acid deposition in the oil sands region of Alberta over three years. > A modified canopy budget model was developed to evaluate H{sup +} budget as the first such attempt in western Canada. > The H{sup +} supply by organic acid leaching from jack pine canopy was a significant source of H{sup +}. > This has implications for establishing critical loads for acid deposition for watersheds in the region. - A modified canopy budget model was developed and organic acid leaching from jack pine canopies was a significant source of H{sup +} in the oil sands region of Alberta.

  17. Nutrient concentrations in coarse and fine woody debris of Populus tremuloides Michx.-dominated forests, northern Minnesota, USA

    Science.gov (United States)

    Klockow, Paul A.; D'Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Contemporary forest harvesting practices, specifically harvesting woody biomass as a source of bioenergy feedstock, may remove more woody debris from a site than conventional harvesting. Woody debris, particularly smaller diameter woody debris, plays a key role in maintaining ecosystem nutrient stores following disturbance. Understanding nutrient concentrations within woody debris is necessary for assessing the long-term nutrient balance consequences of altered woody debris retention, particularly in forests slated for use as bioenergy feedstocks. Nutrient concentrations in downed woody debris of various sizes, decay classes, and species were characterized within one such forest type, Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Nutrient concentrations differed significantly between size and decay classes and generally increased as decay progressed. Fine woody debris (≤ 7.5 cm diameter) had higher nutrient concentrations than coarse woody debris (> 7.5 cm diameter) for all nutrients examined except Na and Mn, and nutrient concentrations varied among species. Concentrations of N, Mn, Al, Fe, and Zn in coarse woody debris increased between one and three orders of magnitude, while K decreased by an order of magnitude with progressing decay. The variations in nutrient concentrations observed here underscore the complexity of woody debris nutrient stores in forested ecosystems and suggest that retaining fine woody debris at harvest may provide a potentially important source of nutrients following intensive removals of bioenergy feedstocks.

  18. The sex-linked region in Populus tremuloides Turesson 141 corresponds to a pericentromeric region of about two million base pairs on P. trichocarpa chromosome 19.

    Science.gov (United States)

    Kersten, B; Pakull, B; Groppe, K; Lueneburg, J; Fladung, M

    2014-03-01

    In the dioecious genus Populus, sex determination has been located to chromosome 19. However, despite a high degree of genome collinearity, various Populus species seem to differ with regard to the location of the sex-determining region on the respective chromosome and the apparent heterogametic sex. In this study, the boundaries of the recombination-suppressed, sex-linked region of the male P. tremuloides clone Turesson 141 were localised by genetic mapping using new SNP and InDel markers. The respective region seems to be located in a pericentromeric position. The corresponding P. trichocarpa genome region spans about two million bp and comprises 65 gene loci, which were bioinformatically evaluated for their potential as candidate genes for sex determination. Three putative transcription factor genes and four genes that are potentially involved in flower development processes, e.g. meristem transition from the vegetative to the reproductive phase, were identified. Populus tremuloides sequence data of the sex-linked region is required for a final search for candidate genes. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Restoring High Priority Habitats for Birds: Aspen and Pine in the Interior West

    Science.gov (United States)

    Rex Sallabanks; Nils D. Christoffersen; Whitney W. Weatherford; Ralph Anderson

    2005-01-01

    This paper describes a long-term habitat restoration project in the Blue Mountains ecoregion, northeast Oregon, that we initiated in May 2000. We focused our restoration activities on two habitats previously identified as being high priority for birds: quaking aspen (Populus tremuloides) and ponderosa pine (Pinus ponderosa). In...

  20. Lake States Aspen Productivity Following Soil Compaction and Organic Matter Removal

    Science.gov (United States)

    Douglas M. Stone

    2002-01-01

    Aspen (Populus tremuloides Michx. and P. grandidentata Michx.) provides wood products, watershed protection, and wildlife habitat for numerous game and non-game species across the northern Great Lakes region. Sustaining the productivity of these ecosystems requires maintaining soil productivity. Management activities that decrease...

  1. Soil properties and aspen development five years after compaction and forest floor removal

    Science.gov (United States)

    Douglas M. Stone; John D. Elioff

    1998-01-01

    Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic...

  2. Transcriptome responses to aluminum stress in roots of aspen (Populus tremula

    Directory of Open Access Journals (Sweden)

    Grisel Nadine

    2010-08-01

    Full Text Available Abstract Background Ionic aluminum (mainly Al3+ is rhizotoxic and can be present in acid soils at concentrations high enough to inhibit root growth. Many forest tree species grow naturally in acid soils and often tolerate high concentrations of Al. Previously, we have shown that aspen (Populus tremula releases citrate and oxalate from roots in response to Al exposure. To obtain further insights into the root responses of aspen to Al, we investigated root gene expression at Al conditions that inhibit root growth. Results Treatment of the aspen roots with 500 μM Al induced a strong inhibition of root growth within 6 h of exposure time. The root growth subsequently recovered, reaching growth rates comparable to that of control plants. Changes in gene expression were determined after 6 h, 2 d, and 10 d of Al exposure. Replicated transcriptome analyses using the Affymetrix poplar genome array revealed a total of 175 significantly up-regulated and 69 down-regulated genes, of which 70% could be annotated based on Arabidopsis genome resources. Between 6 h and 2 d, the number of responsive genes strongly decreased from 202 to 26, and then the number of changes remained low. The responses after 6 h were characterized by genes involved in cell wall modification, ion transport, and oxidative stress. Two genes with prolonged induction were closely related to the Arabidopsis Al tolerance genes ALS3 (for Al sensitive 3 and MATE (for multidrug and toxin efflux protein, mediating citrate efflux. Patterns of expression in different plant organs and in response to Al indicated that the two aspen genes are homologs of the Arabidopsis ALS3 and MATE. Conclusion Exposure of aspen roots to Al results in a rapid inhibition of root growth and a large change in root gene expression. The subsequent root growth recovery and the concomitant reduction in the number of responsive genes presumably reflect the success of the roots in activating Al tolerance mechanisms. The

  3. Moderation of [CO2]-induced gas exchange responses by elevated tropospheric O3 in trembling aspen and sugar maple

    Science.gov (United States)

    Pooja Sharma; Anu Sober; Jaak Sober; Gopi P. Podila; Mark E. Kubiske; William J. Mattson; Judson G. Isebrands; David F. Karnosky

    2003-01-01

    The greenhouse gases CO2 and 03 are increasing in the earth's atmosphere. Little is known about long-term impacts of these two co-occurring gases on forest trees. We have been examining the impacts of these two gases on the physiology and growth of trembling aspen (Populus tremuloides) and sugar...

  4. Acute O3 damage on first year coppice sprouts of aspen and maple sprouts in an open-air experiment

    Science.gov (United States)

    Joseph N.T. Darbah; Wendy S. Jones; Andrew J. Burton; John Nagy; Mark E. Kubiske

    2011-01-01

    We studied the effect of high ozone (O3) concentration (110-490 nmol mol-1) on regenerating aspen (Populus tremuloides) and maple (Acer saccharum) trees at an open-air O3 pollution experiment near Rhinelander WI USA. This study is the first of its kind to examine...

  5. Quantitative predictions of bioconversion of aspen by dilute acid and SPORL pretreatments using a unified combined hydrolysis factor (CHF)

    Science.gov (United States)

    W. Zhu; Carl J. Houtman; J.Y. Zhu; Roland Gleisner; K.F. Chen

    2012-01-01

    A combined hydrolysis factor (CHF) was developed to predict xylan hydrolysis during pretreatments of native aspen (Populus tremuloides) wood chips. A natural extension of previously developed kinetic models allowed us to account for the effect of catalysts by dilute acid and two sulfite pretreatments at different pH values....

  6. Summer-fall home-range fidelity of female elk in northwestern Colorado: Implications for aspen management

    Science.gov (United States)

    April M. Brough; R. Justin DeRose; Mary M. Conner; James N. Long

    2017-01-01

    Understanding the degree of spatial fidelity exhibited by individuals within a species increases our ability to manage for desired future outcomes. Elk (Cervus elaphus) is a closely managed species in the Western US, but there is little research evaluating their summer home-range fidelity. Elk summer-fall homeranges overlap considerably with aspen (Populus tremuloides...

  7. Urbanization-related changes in European aspen (Populus tremula L.): leaf traits and litter decomposition.

    Science.gov (United States)

    Nikula, Suvi; Vapaavuori, Elina; Manninen, Sirkku

    2010-06-01

    We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Urbanization-related changes in European aspen (Populus tremula L.): Leaf traits and litter decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Nikula, Suvi, E-mail: suvi.nikula@helsinki.f [Department of Biosciences, P.O. Box 56, 00014 University of Helsinki (Finland); Vapaavuori, Elina, E-mail: elina.vapaavuori@metla.f [Suonenjoki Research Unit, Finnish Forest Research Institute, Juntintie 154, 77600 Suonenjoki (Finland); Manninen, Sirkku, E-mail: sirkku.manninen@helsinki.f [Department of Environmental Sciences, P.O. Box 56, 00014 University of Helsinki (Finland)

    2010-06-15

    We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter. - Urbanization can modify leaf traits of aspen and accelerate litter decomposition through changes in litter traits as well as in environmental conditions at the decomposition site.

  9. The influence of soil type and altered lignin biosynthesis on the physiology, growth and carbon allocation in Populus tremuloides

    Science.gov (United States)

    Jessica E. Hancock; Kate L. Bradley; Christian P. Giardina; Kurt S. Pregitzer

    2008-01-01

    Plants influence soil carbon (C) formation through the quality and quantity of C released to soil. Soil type, in turn can modify a plant's influence on soil through effects on plant production, tissue quality and regulation of soil C decomposition and stabilization. Wild-type aspen and three transgenic aspen lines expressing reduced stem lignin concentrations and/...

  10. High titer ethanol production from simultaneous enzymatic saccharification and fermentation of aspen at high solids : a comparison between SPORL and dilute acid pretreatments

    Science.gov (United States)

    J.Y. Zhu; R. Gleisner; C.T. Scott; X.L. Luo; S. Tian

    2011-01-01

    Native aspen (Populus tremuloides) was pretreated using sulfuric acid and sodium bisulfite (SPORL) and dilute sulfuric acid alone (DA). Simultaneous enzymatic saccharification and fermentation (SSF) was conducted at 18% solids using commercial enzymes with cellulase loadings ranging from 6 to 15 FPU/g glucan and Saccharomyces cerevisiae Y5. Compared with DA...

  11. Effects of Tropospheric O3 on Trembling Aspen and Interaction with CO2: Results From An O3-Gradient and a Face Experiment

    Science.gov (United States)

    D.F. Karnosky; B. Mankovska; K. Percy; R.E. Dickson; G.K. Podila; J. Sober; A. Noormets; G. Hendrey; Mark D. Coleman; M. Kubiske; K.S. Pregitzer; J.G. Isebrands

    1999-01-01

    Abstract. Over the years, a series of trembling aspen (Populus tremuloides Michx.) clones differing in O3 sensitivity have been identified from OTC studies. Three clones (216 and 271[(O3 tolerant] and 259 [O3 sensitive]) have been characterized for O3...

  12. Wood properties of trembling aspen and paper birch after 5 years of exposure to elevated concentrations of CO2 and O3

    Science.gov (United States)

    Katri Kostiainen; Seija Kaakinen; Elina Warsta; Mark E. Kubiske; Neil D. Nelson; Jaak Sober; David F. Karnosky; Pekka Saranpaa; Elina Vapaavuori

    2008-01-01

    We investigated the interactive effects of elevated concentrations of carbon dioxide ([CO2]) and ozone ([O3]) on radial growth, wood chemistry and structure of five 5-year-old trembling aspen (Populus tremuloides Michx.) clones and the wood chemistry of paper birch (Betula papyrifera...

  13. Tropospheric 03 moderates responses of temperate hardwood forests to elevated CO2: a synthesis of molecular to ecosystem results from the Aspen FACE project

    Science.gov (United States)

    D. F. Karnosky; D. R. Zak; K. S. Pregitzer; C. S. Awmack; J. G. Bockheim; R. E. Dickson; G. R. Hendrey; G. E. Host; J. S. King; B. J. Kopper; E. L. Kruger; M. E. Kubiske; R. L. Lindroth; W. J. Mattson; E. P. McDonald; A. Noormets; E. Oksanen; W. F. J. Parsons; K. E. Percy; G. K. Podila; D. E. Riemenschneider; P. Sharma; R. Thakur; A. S& #244ber; J. S& #244ber; W. S. Jones; S. Anttonen; E. Vapaavuori; B. Mankovska; W. Heilman; J. G. Isebrands

    2003-01-01

    1. The impacts of elevated atmospheric CO2 and/or O3 have been examined over 4 years using an open-air exposure system in an aggrading northern temperate forest containing two different functional groups (the indeterminate, pioneer, 03-sensitive species Trembling Aspen, Populus tremuloides...

  14. Polyploidy in aspen alters plant physiology and drought sensitivity

    Science.gov (United States)

    Greer, B.; Still, C. J.; Brooks, J. R.; Meinzer, F. C.

    2015-12-01

    Polyploids of quaking aspen (Populus tremuloides) may be better suited to dry climatic conditions than diploids. However, the expression of diploid and polyploid functional traits, including water use efficiency, an important component of drought avoidance and tolerance, are not well understood in quaking aspen. In this study diploid and triploid aspen clones' leaf, ramet, and stand functional traits were measured near the Rocky Mountain Biological Laboratory in Gothic, Colorado. The physiology of diploid and triploid aspen, including leaf size, chlorophyll content, stomatal size and density and stomatal conductance, as well as growth rates and carbon isotope discrimination in response to climate (measured in tree rings), were found to be significantly different between ploidy levels. These findings demonstrate different sensitivities of diploid and triploid clones to drought related climate stressors which may impact strategies for aspen forest management and conservation.

  15. Wood Quality and Growth Characterization across Intra- and Inter-Specific Hybrid Aspen Clones

    Directory of Open Access Journals (Sweden)

    Shawn D. Mansfield

    2013-09-01

    Full Text Available Trembling aspen (Populus tremuloides Michx. is one of the most abundant poplar species in North America; it is native, displays substantial breadth in distribution inhabiting several geographical and climatic ecoregions, is notable for its rapid growth, and is ecologically and economically important. As the demand for raw material continues to increase rapidly, there is a pressing need to improve both tree quality and growth rates via breeding efforts. Hybridization is considered one of the most promising options to simultaneously accelerate these tree characteristics, as it takes advantage of heterosis. Two aspen species showing particular promise for hybridization with trembling aspen are European aspen (P. tremula and Chinese aspen (P. davidiana because their native climates are similar to that of P. tremuloides and are also very easy to hybridize. In 2003, aspen clones were planted in Athabasca, Alberta from the following species crosses: open pollinated (OP P. tremuloides (NN, OP P. davidiana (CC, P. tremula × P. tremula (EE, P. tremula × P. tremuloides (EN, and P. tremuloides × P. davidiana (CN. In November 2010, growth measurements and core samples were taken from seven-year field grown clones. Comparisons of the mean growth and cell wall traits were made between crosses using generalized linear model least squares means tests for stem volume, fiber length, fiber width, coarseness, wood density, microfibril angle, total cell wall carbohydrate and lignin content, and lignin composition. The results clearly indicated that the inter-specific crosses offer a means to breed for more desirable wood characteristics than the intra-specific Populus spp. crosses.

  16. Spring leaf flush in aspen (Populus tremuloides) clones is altered by growth at elevated carbon dioxide and elevated ozone

    Science.gov (United States)

    Early spring leaf out is important to the success of trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how elevated carbon dioxide concentration and elevated ozone concentration altered leaf area index development in a clos...

  17. Can elevated CO2 and ozone shift the genetic composition of aspen (Populus tremuloides) stands? New Phytologist

    Science.gov (United States)

    Emily V. Moran; Mark E. Kubiske

    2013-01-01

    The world's forests are currently exposed to increasing concentrations of carbon dioxide (CO2) and ozone (O3). Both pollutants can potentially exert a selective effect on plant populations. This, in turn, may lead to changes in ecosystem properties, such as carbon sequestration. Here, we report how elevated CO

  18. Impacts of post-harvest slash and live-tree retention on biomass and nutrient stocks in Populus tremuloides Michx.-dominated forests, northern Minnesota, USA

    Science.gov (United States)

    Klockow, Paul A.; D'Amato, Anthony W.; Bradford, John B.

    2013-01-01

    Globally, there is widespread interest in using forest-derived biomass as a source of bioenergy. While conventional timber harvesting generally removes only merchantable tree boles, harvesting biomass feedstock can remove all forms of woody biomass (i.e., live and dead standing woody vegetation, downed woody debris, and stumps) resulting in a greater loss of biomass and nutrients as well as more severe habitat alteration. To investigate the potential impacts of this practice, this study examined the initial impacts (pre- and post-harvest) of various levels of slash and live-tree retention on biomass and nutrient stocks, including carbon (C), nitrogen (N), calcium (Ca), potassium (K), and phosphorus (P), in Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Treatments examined included three levels of slash retention, whole-tree harvest (WTH), 20% slash retention (20SR), and stem-only harvest (SOH), factored with three levels of green-tree retention, no trees retained (NONE), dispersed retention (DISP), and aggregate retention (AGR). Slash retention was the primary factor affecting post-harvest biomass and nutrient stocks, including woody debris pools. Compared to the unharvested control, stocks of biomass, carbon, and nutrients, including N, Ca, K, and P, in woody debris were higher in all treatments. Stem-only harvests typically contained greater biomass and nutrient stocks than WTH, although biomass and nutrients within 20SR, a level recommended by biomass harvesting guidelines in the US and worldwide, generally did not differ from WTH or SOH. Biomass in smaller-diameter slash material (typically 2.5-22.5 cm in diameter) dominated the woody debris pool following harvest regardless of slash retention level. Trends among treatments in this diameter range were generally similar to those in the total woody debris pool. Specifically, SOH contained significantly greater amounts of biomass than WTH while 20SR was not different from either WTH or

  19. Fire regimes of quaking aspen in the Mountain West

    Science.gov (United States)

    Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

    2013-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widespread tree species in North America, and it is found throughout much of the Mountain West (MW) across a broad range of bioclimatic regions. Aspen typically regenerates asexually and prolifically after fire, and due to its seral status in many western conifer forests, aspen is often considered dependent upon disturbance for persistence. In many landscapes, historical evidence for post-fire aspen establishment is clear, and following extended fire-free periods senescing or declining aspen overstories sometimes lack adequate regeneration and are succeeding to conifers. However, aspen also forms relatively stable stands that contain little or no evidence of historical fire. In fact, aspen woodlands range from highly fire-dependent, seral communities to relatively stable, self-replacing, non-seral communities that do not require fire for persistence. Given the broad geographic distribution of aspen, fire regimes in these forests likely co-vary spatially with changing community composition, landscape setting, and climate, and temporally with land use and climate – but relatively few studies have explicitly focused on these important spatiotemporal variations. Here we reviewed the literature to summarize aspen fire regimes in the western US and highlight knowledge gaps. We found that only about one-fourth of the 46 research papers assessed for this review could be considered fire history studies (in which mean fire intervals were calculated), and all but one of these were based primarily on data from fire-scarred conifers. Nearly half of the studies reported at least some evidence of persistent aspen in the absence of fire. We also found that large portions of the MW have had little or no aspen fire history research. As a result of this review, we put forth a classification framework for aspen that is defined by key fire regime parameters (fire severity and probability), and that reflects underlying biophysical

  20. Abaxial Greening Phenotype in Hybrid Aspen

    Directory of Open Access Journals (Sweden)

    Julia S. Nowak

    2013-04-01

    Full Text Available The typical angiosperm leaf, as in Arabidopsis, is bifacial consisting of top (adaxial and bottom (abaxial surfaces readily distinguishable by the underlying cell type (palisade and spongy mesophyll, respectively. Species of the genus Populus have leaves that are either conventionally bifacial or isobilateral. Isobilateral leaves have palisade mesophyll on the top and bottom of the leaf, making the two sides virtually indistinguishable at the macroscopic level. In poplars this has been termed the “abaxial greening” phenotype. Previous work has implicated ASYMMETRIC LEAVES1 (AS1 as an essential determinant of palisade mesophyll development. This gene, as well as other genes (84 in all putatively involved in setting the dorsiventral axis of leaves, were investigated in two Populus species: black cottonwood (Populus trichocarpa and hybrid aspen (P. tremula x tremuloides, representative of each leaf type (bifacial and isobilateral, respectively. Poplar orthologs of AS1 have significantly higher expression in aspen leaf blade and lower in the petiole, suggestive of a potential role in the isobilateral leaf phenotype consistent with the previously observed phenotypes. Furthermore, an ABERRANT TESTA SHAPE (ATS ortholog has significantly lower expression in aspen leaf tissue, also suggesting a possible contribution of this gene to abaxial greening.

  1. Drought causes reduced growth of trembling aspen in western Canada.

    Science.gov (United States)

    Chen, Lei; Huang, Jian-Guo; Alam, Syed Ashraful; Zhai, Lihong; Dawson, Andria; Stadt, Kenneth J; Comeau, Philip G

    2017-07-01

    Adequate and advance knowledge of the response of forest ecosystems to temperature-induced drought is critical for a comprehensive understanding of the impacts of global climate change on forest ecosystem structure and function. Recent massive decline in aspen-dominated forests and an increased aspen mortality in boreal forests have been associated with global warming, but it is still uncertain whether the decline and mortality are driven by drought. We used a series of ring-width chronologies from 40 trembling aspen (Populus tremuloides Michx.) sites along a latitudinal gradient (from 52° to 58°N) in western Canada, in an attempt to clarify the impacts of drought on aspen growth by using Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Results indicated that prolonged and large-scale droughts had a strong negative impact on trembling aspen growth. Furthermore, the spatiotemporal variability of drought indices is useful for explaining the spatial heterogeneity in the radial growth of trembling aspen. Due to ongoing global warming and rising temperatures, it is likely that severer droughts with a higher frequency will occur in western Canada. As trembling aspen is sensitive to drought, we suggest that drought indices could be applied to monitor the potential effects of increased drought stress on aspen trees growth, achieve classification of eco-regions and develop effective mitigation strategies to maintain western Canadian boreal forests. © 2017 John Wiley & Sons Ltd.

  2. Development of F1 hybrid population and the high-density linkage map for European aspen (Populus tremula L.) using RADseq technology.

    Science.gov (United States)

    Zhigunov, Anatoly V; Ulianich, Pavel S; Lebedeva, Marina V; Chang, Peter L; Nuzhdin, Sergey V; Potokina, Elena K

    2017-11-14

    Restriction-site associated DNA sequencing (RADseq) technology was recently employed to identify a large number of single nucleotide polymorphisms (SNP) for linkage mapping of a North American and Eastern Asian Populus species. However, there is also the need for high-density genetic linkage maps for the European aspen (P. tremula) as a tool for further mapping of quantitative trait loci (QTLs) and marker-assisted selection of the Populus species native to Europe. We established a hybrid F1 population from the cross of two aspen parental genotypes diverged in their phenological and morphological traits. We performed RADseq of 122 F1 progenies and two parents yielding 15,732 high-quality SNPs that were successfully identified using the reference genome of P. trichocarpa. 2055 SNPs were employed for the construction of maternal and paternal linkage maps. The maternal linkage map was assembled with 1000 SNPs, containing 19 linkage groups and spanning 3054.9 cM of the genome, with an average distance of 3.05 cM between adjacent markers. The paternal map consisted of 1055 SNPs and the same number of linkage groups with a total length of 3090.56 cM and average interval distance of 2.93 cM. The linkage maps were employed for QTL mapping of one-year-old seedlings height variation. The most significant QTL (LOD = 5.73) was localized to LG5 (96.94 cM) of the male linkage map, explaining 18% of the phenotypic variation. The set of 15,732 SNPs polymorphic in aspen and high-density genetic linkage maps constructed for the P. tremula intra-specific cross will provide a valuable source for QTL mapping and identification of candidate genes facilitating marker-assisted selection in European aspen.

  3. An efficient Agrobacterium-mediated transformation and regeneration system for leaf explants of two elite aspen hybrid clones Populus alba × P. berolinensis and Populus davidiana × P. bolleana.

    Science.gov (United States)

    Wang, Haihai; Wang, Cuiting; Liu, Hua; Tang, Renjie; Zhang, Hongxia

    2011-11-01

    Transgenic technology has been successfully used for gene function analyses and trait improvement in cereal plants. However, its usage is limited in woody plants, especially in the difficult-to-transform but commercially viable hybrid poplar. In this work, an efficient regeneration and transformation system was established for the production of two hybrid aspen clones: Populus alba × P. berolinensis and Populus davidiana × P. bolleana. A plant transformation vector designed to express the reporter gene uidA, encoding β-glucuronidase (GUS), driven by the cauliflower mosaic virus 35S promoter, was used to detect transformation event at early stages of plant regeneration, and to optimize the parameters that may affect poplar transformation efficiency. Bacterium strain and age of leaf explant are two major factors that affect transformation efficiency. Addition of thidiazuron (TDZ) improved both regeneration and transformation efficiency. The transformation efficiency is approximately 9.3% for P. alba × P. berolinensis and 16.4% for P. davidiana × P. bolleana. Using this system, transgenic plants were usually produced in less than 1 month after co-cultivation. The growth characteristics and morphology of transgenic plants were identical to the untransformed wild type plants, and the transgenes could be inherited by vegetative propagation, as confirmed by PCR, Southern blotting, RT-PCR and β-glucuronidase staining analyses. The establishment of this system will help to facilitate the studies of gene functions in tree growth and development at a genome level, and as well as the introduction of some valuable traits in aspen breeding.

  4. Impact of simulated herbivory on water relations of aspen (Populus tremuloides) seedlings: the role of new tissue in the hydraulic conductivity recovery cycle

    Science.gov (United States)

    David A. Galvez; M.T. Tyree

    2009-01-01

    Physiological mechanisms behind plant-herbivore interactions are commonly approached as input-output systems where the role of plant physiology is viewed as a black box. Studies evaluating impacts of defoliation on plant physiology have mostly focused on changes in photosynthesis while the overall impact on plant water relations is largely unknown. Stem hydraulic...

  5. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

    2008-10-01

    Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

  6. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Science.gov (United States)

    Zeigenfuss, Linda C.; Binkley, Dan; Tuskan, Gerald A.; Romme, William H.; Yin, Tongming; DiFazio, Stephen; Singer, Francis J.

    2008-01-01

    Lack of recruitment and canopy replacement of aspen (Populus tremuloides) stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado have been a cause of concern for more than 70 years. We used a combination of traditional dendrochronology and genetic techniques as well as measuring the characteristics of regenerating and nonregenerating stands on the elk winter range to determine when and under what conditions and estimated elk densities these stands established and through what mechanisms they may regenerate. The period from 1975 to 1995 at low elevation on the east side had 80-95 percent fewer aspen stems than would be expected based on the trend from 1855 through 1965. The age structure of aspen in the park indicates that the interacting effects of fires, elk population changes, and livestock grazing had more-or-less consistent effects on aspen from 1855 to 1965. The lack of a significant change in aspen numbers in recent decades in the higher elevation and west side parts of the park supports the idea that the extensive effects of elk browsing have been more important in reducing aspen numbers than other factors. The genetic variation of aspen populations in RMNP is high at the molecular level. We expected to find that most patches of aspen in the park were composed of a single clone of genetically identical trees, but in fact just 7 percent of measured aspen patches consisted of a single clone. A large frequency of polyploid (triploid and tetraploid) genotypes were found on the low elevation, east-side elk winter range. Nonregenerating aspen stands on the winter range had greater annual offtake, shorter saplings, and lower density of mid-height (1.5-2.5 m) saplings than regenerating stands. Overwinter elk browsing, however, did not appear to inhibit the leader length of aspen saplings. The winter range aspen stands of RMNP appear to be highly resilient in the face of

  7. Aspen SUCROSE TRANSPORTER3 allocates carbon into wood fibers.

    Science.gov (United States)

    Mahboubi, Amir; Ratke, Christine; Gorzsás, András; Kumar, Manoj; Mellerowicz, Ewa J; Niittylä, Totte

    2013-12-01

    Wood formation in trees requires carbon import from the photosynthetic tissues. In several tree species, including Populus species, the majority of this carbon is derived from sucrose (Suc) transported in the phloem. The mechanism of radial Suc transport from phloem to developing wood is not well understood. We investigated the role of active Suc transport during secondary cell wall formation in hybrid aspen (Populus tremula × Populus tremuloides). We show that RNA interference-mediated reduction of PttSUT3 (for Suc/H(+) symporter) during secondary cell wall formation in developing wood caused thinner wood fiber walls accompanied by a reduction in cellulose and an increase in lignin. Suc content in the phloem and developing wood was not significantly changed. However, after (13)CO2 assimilation, the SUT3RNAi lines contained more (13)C than the wild type in the Suc-containing extract of developing wood. Hence, Suc was transported into developing wood, but the Suc-derived carbon was not efficiently incorporated to wood fiber walls. A yellow fluorescent protein:PttSUT3 fusion localized to plasma membrane, suggesting that reduced Suc import into developing wood fibers was the cause of the observed cell wall phenotype. The results show the importance of active Suc transport for wood formation in a symplasmically phloem-loading tree species and identify PttSUT3 as a principal transporter for carbon delivery into secondary cell wall-forming wood fibers.

  8. Recent Y chromosome divergence despite ancient origin of dioecy in poplars (Populus).

    Science.gov (United States)

    Geraldes, A; Hefer, C A; Capron, A; Kolosova, N; Martinez-Nuñez, F; Soolanayakanahally, R Y; Stanton, B; Guy, R D; Mansfield, S D; Douglas, C J; Cronk, Q C B

    2015-07-01

    All species of the genus Populus (poplar, aspen) are dioecious, suggesting an ancient origin of this trait. Despite some empirical counter examples, theory suggests that nonrecombining sex-linked regions should quickly spread, eventually becoming heteromorphic chromosomes. In contrast, we show using whole-genome scans that the sex-associated region in Populus trichocarpa is small and much younger than the age of the genus. This indicates that sex determination is highly labile in poplar, consistent with recent evidence of 'turnover' of sex-determination regions in animals. We performed whole-genome resequencing of 52 P. trichocarpa (black cottonwood) and 34 Populus balsamifera (balsam poplar) individuals of known sex. Genomewide association studies in these unstructured populations identified 650 SNPs significantly associated with sex. We estimate the size of the sex-linked region to be ~100 kbp. All SNPs significantly associated with sex were in strong linkage disequilibrium despite the fact that they were mapped to six different chromosomes (plus 3 unmapped scaffolds) in version 2.2 of the reference genome. We show that this is likely due to genome misassembly. The segregation pattern of sex-associated SNPs revealed this to be an XY sex-determining system. Estimated divergence times of X and Y haplotype sequences (6-7 Ma) are much more recent than the divergence of P. trichocarpa (poplar) and Populus tremuloides (aspen). Consistent with this, in P. tremuloides, we found no XY haplotype divergence within the P. trichocarpa sex-determining region. These two species therefore have a different genomic architecture of sex, suggestive of at least one turnover event in the recent past. © 2015 John Wiley & Sons Ltd.

  9. Are wolves saving Yellowstone's aspen? A landscape-level test of a behaviorally mediated trophic cascade

    Science.gov (United States)

    Kauffman, Matthew J.; Brodie, Jedediah F.; Jules, Erik S.

    2010-01-01

    Behaviorally mediated trophic cascades (BMTCs) occur when the fear of predation among herbivores enhances plant productivity. Based primarily on systems involving small-bodied predators, BMTCs have been proposed as both strong and ubiquitous in natural ecosystems. Recently, however, synthetic work has suggested that the existence of BMTCs may be mediated by predator hunting mode, whereby passive (sit-and-wait) predators have much stronger effects than active (coursing) predators. One BMTC that has been proposed for a wide-ranging active predator system involves the reintroduction of wolves (Canis lupus) to Yellowstone National Park, USA, which is thought to be leading to a recovery of trembling aspen (Populus tremuloides) by causing elk (Cervus elaphus) to avoid foraging in risky areas. Although this BMTC has been generally accepted and highly popularized, it has never been adequately tested. We assessed whether wolves influence aspen by obtaining detailed demographic data on aspen stands using tree rings and by monitoring browsing levels in experimental elk exclosures arrayed across a gradient of predation risk for three years. Our study demonstrates that the historical failure of aspen to regenerate varied widely among stands (last recruitment year ranged from 1892 to 1956), and our data do not indicate an abrupt cessation of recruitment. This pattern of recruitment failure appears more consistent with a gradual increase in elk numbers rather than a rapid behavioral shift in elk foraging following wolf extirpation. In addition, our estimates of relative survivorship of young browsable aspen indicate that aspen are not currently recovering in Yellowstone, even in the presence of a large wolf population. Finally, in an experimental test of the BMTC hypothesis we found that the impacts of elk browsing on aspen demography are not diminished in sites where elk are at higher risk of predation by wolves. These findings suggest the need to further evaluate how trophic

  10. Barrier to gene flow between two ecologically divergent Populus species, P. alba (white poplar) and P. tremula (European aspen): the role of ecology and life history in gene introgression.

    Science.gov (United States)

    Lexer, C; Fay, M F; Joseph, J A; Nica, M-S; Heinze, B

    2005-04-01

    The renewed interest in the use of hybrid zones for studying speciation calls for the identification and study of hybrid zones across a wide range of organisms, especially in long-lived taxa for which it is often difficult to generate interpopulation variation through controlled crosses. Here, we report on the extent and direction of introgression between two members of the "model tree" genus Populus: Populus alba (white poplar) and Populus tremula (European aspen), across a large zone of sympatry located in the Danube valley. We genotyped 93 hybrid morphotypes and samples from four parental reference populations from within and outside the zone of sympatry for a genome-wide set of 20 nuclear microsatellites and eight plastid DNA restriction site polymorphisms. Our results indicate that introgression occurs preferentially from P. tremula to P. alba via P. tremula pollen. This unidirectional pattern is facilitated by high levels of pollen vs. seed dispersal in P. tremula (pollen/seed flow = 23.9) and by great ecological opportunity in the lowland floodplain forest in proximity to P. alba seed parents, which maintains gene flow in the direction of P. alba despite smaller effective population sizes (N(e)) in this species (P. alba N(e)c. 500-550; P. tremula N(e)c. 550-700). Our results indicate that hybrid zones will be valuable tools for studying the genetic architecture of the barrier to gene flow between these two ecologically divergent Populus species.

  11. Variation in Trembling Aspen and White Spruce Wood Quality Grown in Mixed and Single Species Stands in the Boreal Mixedwood Forest

    Directory of Open Access Journals (Sweden)

    Francis De Araujo

    2015-05-01

    Full Text Available The Canadian boreal forest is largely represented by mixed wood forests of white spruce (Picea glauca (Moench Voss and trembling aspen (Populus tremuloides Michx. In this study, a total of 300 trees originating from three sites composed of trembling aspen and white spruce with varying compositions were investigated for wood quality traits: one site was composed mainly of aspen, one mainly of spruce and a third was a mixed site. Four wood quality traits were examined: wood density, microfibril angle (MFA, fibre characteristics, and cell wall chemistry. Social classes were also determined for each site in an attempt to provide a more in-depth comparison. Wood density showed little variation among sites for both species, with only significant differences occurring between social classes. The aspen site showed statistically lower MFAs than the aspen from the mixed site, however, no differences were observed when comparing spruce. Fibre characteristics were higher in the pure species sites for both species. There were no differences in carbohydrate contents across sites, while lignin content varied. Overall, the use of social classes did not refine the characterization of sites.

  12. Climatic Sensitivity of a Mixed Forest Association of White Spruce and Trembling Aspen at Their Southern Range Limit

    Directory of Open Access Journals (Sweden)

    Sophan Chhin

    2016-10-01

    Full Text Available Climatic sensitivity of white spruce (Picea glauca (Moench Voss was examined growing in association with trembling aspen (Populus tremuloides Michx. at their southern limit of distribution in a transitional ecotone between the southern boreal forest and northern prairie region. The study was carried out in the Spruce Woods Provincial Park (SWPP located in southwestern Manitoba, Canada. The dry regional climate restricted trembling aspen growth during the growing season via moisture deficiency and temperature induced drought stress. Warm, mild winters also negatively affected radial growth of trembling aspen. Growth of white spruce was moderated by conditions within the aspen stands as radial growth patterns showed low variability from year to year, a low common growth signal, and a stronger response to temperature than to precipitation. Nonetheless, the dry regional climate still restricted growth of white spruce during the growing season via temperature induced drought stress. The findings of the study for white spruce support the stress gradient hypothesis in which facilitative interactions between tree species are expected under harsher environmental conditions.

  13. Transgenic hybrid aspen trees with increased gibberellin (GA) concentrations suggest that GA acts in parallel with FLOWERING LOCUS T2 to control shoot elongation.

    Science.gov (United States)

    Eriksson, Maria E; Hoffman, Daniel; Kaduk, Mateusz; Mauriat, Mélanie; Moritz, Thomas

    2015-02-01

    Bioactive gibberellins (GAs) have been implicated in short day (SD)-induced growth cessation in Populus, because exogenous applications of bioactive GAs to hybrid aspens (Populus tremula × tremuloides) under SD conditions delay growth cessation. However, this effect diminishes with time, suggesting that plants may cease growth following exposure to SDs due to a reduction in sensitivity to GAs. In order to validate and further explore the role of GAs in growth cessation, we perturbed GA biosynthesis or signalling in hybrid aspen plants by overexpressing AtGA20ox1, AtGA2ox2 and PttGID1.3 (encoding GA biosynthesis enzymes and a GA receptor). We found trees with elevated concentrations of bioactive GA, due to overexpression of AtGA20ox1, continued to grow in SD conditions and were insensitive to the level of FLOWERING LOCUS T2 (FT2) expression. As transgenic plants overexpressing the PttGID1.3 GA receptor responded in a wild-type (WT) manner to SD conditions, this insensitivity did not result from limited receptor availability. As high concentrations of bioactive GA during SD conditions were sufficient to sustain shoot elongation growth in hybrid aspen trees, independent of FT2 expression levels, we conclude elongation growth in trees is regulated by both GA- and long day-responsive pathways, similar to the regulation of flowering in Arabidopsis thaliana. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  14. A genome-wide screen for ethylene-induced ethylene response factors (ERFs) in hybrid aspen stem identifies ERF genes that modify stem growth and wood properties.

    Science.gov (United States)

    Vahala, Jorma; Felten, Judith; Love, Jonathan; Gorzsás, András; Gerber, Lorenz; Lamminmäki, Airi; Kangasjärvi, Jaakko; Sundberg, Björn

    2013-10-01

    Ethylene Response Factors (ERFs) are a large family of transcription factors that mediate responses to ethylene. Ethylene affects many aspects of wood development and is involved in tension wood formation. Thus ERFs could be key players connecting ethylene action to wood development. We identified 170 gene models encoding ERFs in the Populus trichocarpa genome. The transcriptional responses of ERF genes to ethylene treatments were determined in stem tissues of hybrid aspen (Populus tremula × tremuloides) by qPCR. Selected ethylene-responsive ERFs were overexpressed in wood-forming tissues and characterized for growth and wood chemotypes by FT-IR. Fifty ERFs in Populus showed more than five-fold increased transcript accumulation in response to ethylene treatments. Twenty-six ERFs were selected for further analyses. A majority of these were induced during tension wood formation. Overexpression of ERFs 18, 21, 30, 85 and 139 in wood-forming tissues of hybrid aspen modified the wood chemotype. Moreover, overexpression of ERF139 caused a dwarf-phenotype with altered wood development, and overexpression of ERF18, 34 and 35 slightly increased stem diameter. We identified ethylene-induced ERFs that respond to tension wood formation, and modify wood formation when overexpressed. This provides support for their role in ethylene-mediated regulation of wood development. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  15. Biosynthesis of cellulose‐enriched tension wood in Populus: global analysis of transcripts and metabolites identifies biochemical and developmental regulators in secondary wall biosynthesis

    National Research Council Canada - National Science Library

    Andersson‐Gunnerås, Sara; Mellerowicz, Ewa J; Love, Jonathan; Segerman, Bo; Ohmiya, Yasunori; Coutinho, Pedro M; Nilsson, Peter; Henrissat, Bernard; Moritz, Thomas; Sundberg, Björn

    2006-01-01

    ...‐forming tissues in Populus tremula (L.) ×  tremuloides (Michx.) and data from transcript profiling using microarray and metabolite analysis were obtained during TW formation in Populus tremula (L...

  16. Lignin isolated from primary walls of hybrid aspen cell cultures indicates significant differences in lignin structure between primary and secondary cell wall.

    Science.gov (United States)

    Christiernin, Maria; Ohlsson, Anna B; Berglund, Torkel; Henriksson, Gunnar

    2005-08-01

    Hybrid aspen (Populus tremula x tremuloides) cell cultures were grown for 7, 14 and 21 days. The cell cultures formed primary cell walls but no secondary cell wall according to carbohydrate analysis and microscopic characterization. The primary walls were lignified, increasingly with age, according to Klason lignin analysis. Presence of lignin in the primary walls, with a higher content in 21-day old cells than in 7-day old cells, was further supported by phloroglucinol/HCl reagent test and confocal microscopy after both immunolocalization and staining with acriflavin. Both laccase and peroxidase activity were found in the cultures and the activity increased during lignin formation. The lignin from the cell culture material was compared to lignin from mature aspen wood, where most of the lignin originates in the secondary cell wall, and which served as our secondary cell wall control. Lignin from the cell walls was isolated and characterized by thioacidolysis followed by gas chromatography and mass spectrometry. The lignin in the cell cultures differed from lignin of mature aspen wood in that it consisted exclusively of guaiacyl units, and had a more condensed structure. Five lignin structures were identified by mass spectrometry in the cell suspension cultures. The results indicate that the hybrid aspen cell culture used in this investigation may be a convenient experimental system for studies of primary cell wall lignin.

  17. Wood properties of Populus and Betula in long-term exposure to elevated CO₂ and O₃.

    Science.gov (United States)

    Kostiainen, Katri; Saranpää, Pekka; Lundqvist, Sven-Olof; Kubiske, Mark E; Vapaavuori, Elina

    2014-06-01

    We studied the interactive effects of elevated concentrations of CO2 and O3 on radial growth and wood properties of four trembling aspen (Populus tremuloides Michx.) clones and paper birch (Betula papyrifera Marsh.) saplings. The material for the study was collected from the Aspen FACE (free-air CO2 enrichment) experiment in Rhinelander (WI, USA). Trees had been exposed to four treatments [control, elevated CO2 (560 ppm), elevated O3 (1.5 times ambient) and combined CO2 + O3 ] during growing seasons 1998-2008. Most treatment responses were observed in the early phase of experiment. Our results show that the CO2- and O3-exposed aspen trees displayed a differential balance between efficiency and safety of water transport. Under elevated CO2, radial growth was enhanced and the trees had fewer but hydraulically more efficient larger diameter vessels. In contrast, elevated O3 decreased radial growth and the diameters of vessels and fibres. Clone-specific decrease in wood density and cell wall thickness was observed under elevated CO2 . In birch, the treatments had no major impacts on wood anatomy or wood density. Our study indicates that short-term impact studies conducted with young seedlings may not give a realistic view of long-term ecosystem responses. © 2013 John Wiley & Sons Ltd.

  18. Contributions of insects and droughts to growth decline of trembling aspen mixed boreal forest of western Canada.

    Science.gov (United States)

    Chen, Lei; Huang, Jian-Guo; Dawson, Andria; Zhai, Lihong; Stadt, Kenneth J; Comeau, Philip G; Whitehouse, Caroline

    2017-08-01

    Insects, diseases, fire and drought and other disturbances associated with global climate change contribute to forest decline and mortality in many parts of the world. Forest decline and mortality related to drought or insect outbreaks have been observed in North American aspen forests. However, little research has been done to partition and estimate their relative contributions to growth declines. In this study, we combined tree-ring width and basal area increment series from 40 trembling aspen (Populus tremuloides Michx.) sites along a latitudinal gradient (from 52° to 58°N) in western Canada and attempted to investigate the effect of drought and insect outbreaks on growth decline, and simultaneously partition and quantify their relative contributions. Results indicated that the influence of drought on forest decline was stronger than insect outbreaks, although both had significant effects. Furthermore, the influence of drought and insect outbreaks showed spatiotemporal variability. In addition, our data suggest that insect outbreaks could be triggered by warmer early spring temperature instead of drought, implicating that potentially increased insect outbreaks are expected with continued warming springs, which may further exacerbate growth decline and death in North America aspen mixed forests. © 2017 John Wiley & Sons Ltd.

  19. Can Carbon Fluxes Explain Differences in Soil Organic Carbon Storage under Aspen and Conifer Forest Overstories?

    Directory of Open Access Journals (Sweden)

    Antra Boča

    2017-04-01

    Full Text Available Climate- and management-induced changes in tree species distributions are raising questions regarding tree species-specific effects on soil organic carbon (SOC storage and stability. Quaking aspen (Populus tremuloides Michx. is the most widespread tree species in North America, but fire exclusion often promotes the succession to conifer dominated forests. Aspen in the Western US have been found to store more SOC in the mineral soil than nearby conifers, but we do not yet fully understand the source of this differential SOC accumulation. We measured total SOC storage (0–50 cm, characterized stable and labile SOC pools, and quantified above- and belowground litter inputs and dissolved organic carbon (DOC fluxes during snowmelt in plots located in N and S Utah, to elucidate the role of foliage vs. root detritus in SOC storage and stabilization in both ecosystems. While leaf litterfall was twice as high under aspen as under conifers, input of litter-derived DOC with snowmelt water was consistently higher under conifers. Fine root (<2 mm biomass, estimated root detritus input, and root-derived DOC fluxes were also higher under conifers. A strong positive relationship between root and light fraction C content suggests that root detritus mostly fueled the labile fraction of SOC. Overall, neither differences in above- and belowground detritus C inputs nor in detritus-derived DOC fluxes could explain the higher and more stable SOC pools under aspen. We hypothesize that root–microbe–soil interactions in the rhizosphere are more likely to drive these SOC pool differences.

  20. Assisted migration to address climate change: recommendations for aspen reforestation in western Canada.

    Science.gov (United States)

    Gray, Laura K; Gylander, Tim; Mbogga, Michael S; Chen, Pei-Yu; Hamann, Andreas

    2011-07-01

    Human-aided movement of species populations in large-scale reforestation programs could be a potent and cost-effective climate change adaptation strategy. Such large-scale management interventions, however, tend to entail the risks of unintended consequences, and we propose that three conditions should be met before implementing assisted migration in reforestation programs: (1) evidence of a climate-related adaptational lag, (2) observed biological impacts, and (3) robust model projections to target assisted migration efforts. In a case study of aspen (Populus tremuloides Michaux.) we use reciprocal transplant experiments to study adaptation of tree populations to local environments. Second, we monitor natural aspen populations using the MODIS enhanced vegetation index as a proxy for forest health and productivity. Last, we report results from bioclimate envelope models that predict suitable habitat for locally adapted genotypes under observed and predicted climate change. The combined results support assisted migration prescriptions and indicate that the risk of inaction likely exceeds the risk associated with changing established management practices. However, uncertainty in model projections also implies that we are restricted to a relatively short 20-year planning horizon for prescribing seed movement in reforestation programs. We believe that this study exemplifies a safe and realistic climate change adaptation strategy based on multiple sources of information and some understanding of the uncertainty associated with recommendations for assisted migration. Ad hoc migration prescriptions without a similar level of supporting information should be avoided in reforestation programs.

  1. Aspen Delineation - Aspen Delineation Project [ds362

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands, where aspen assessment data was gathered. Aspen assessment information corresponding to this polygon layer can...

  2. Organo-mineral interactions promote greater soil organic carbon stability under aspen in semi-arid montane forests in Utah

    Science.gov (United States)

    Van Miegroet, H.; Roman Dobarco, M.

    2014-12-01

    Forest species influence soil organic carbon (SOC) storage through litter input, which in interaction with soil microclimate, texture and mineralogy, lead to different SOC stabilization and storage patterns. We sampled mineral soil (0-15 cm) across the ecotone between aspen (Populus tremuloides) and mixed conifers stands (Abies lasiocarpa and Pseudotsuga menziesii) in semi-arid montane forests from Utah, to investigate the influence of vegetation vs. site characteristics on SOC stabilization, storage and chemistry. SOC was divided into light fraction (LF), mineral-associated SOC in the silt and clay fraction (MoM), and a dense subfraction > 53 μm (SMoM) using wet sieving and electrostatic attraction. SOC decomposability and solubility was derived from long term laboratory incubations and hot water extractions (HWE). Fourier transform infrared spectroscopy (FTIR) was used to study differences in chemical functional groups in LF and MoM. Vegetation cover did not affect SOC storage (47.0 ± 16.5 Mg C ha-1), SOC decomposability (cumulative CO2-C release of 93.2 ± 65.4 g C g-1 C), or SOC solubility (9.8 ± 7.2 mg C g-1 C), but MoM content increased with presence of aspen [pure aspen (31.2 ± 15.1 Mg C ha-1) > mixed (25.7 ± 8.8 Mg C ha-1) > conifer (22.8 ± 9.0 Mg C ha-1)]. Organo-mineral complexes reduced biological availability of SOC, indicated by the negative correlation between silt+clay (%) and decomposable SOC per gram of C (r = -0.48, p = 0.001) or soluble SOC (r = -0.59, p molecules (e.g., polysaccharides) of plant or microbial origin. FTIR spectra clustered by sites with similar parent material rather than by vegetation cover. This suggests that initial differences in litter chemistry between aspen and conifers converged into similar MoM chemistry within sites.

  3. Interactions between Bacteria And Aspen Defense Chemicals at the Phyllosphere - Herbivore Interface.

    Science.gov (United States)

    Mason, Charles J; Lowe-Power, Tiffany M; Rubert-Nason, Kennedy F; Lindroth, Richard L; Raffa, Kenneth F

    2016-03-01

    Plant- and insect-associated microorganisms encounter a diversity of allelochemicals, and require mechanisms for contending with these often deleterious and broadly-acting compounds. Trembling aspen, Populus tremuloides, contains two principal groups of defenses, phenolic glycosides (salicinoids) and condensed tannins, which differentially affect the folivorous gypsy moth, Lymantria dispar, and its gut symbionts. The bacteria genus Acinetobacter is frequently associated with both aspen foliage and gypsy moth consuming that tissue, and one isolate, Acinetobacter sp. R7-1, previously has been shown to metabolize phenolic glycosides. In this study, we aimed to characterize further interactions between this Acinetobacter isolate and aspen secondary metabolites. We assessed bacterial carbon utilization and growth in response to different concentrations of phenolic glycosides and condensed tannins. We also tested if enzyme inhibitors reduce bacterial growth and catabolism of phenolic glycosides. Acinetobacter sp. R7-1 utilized condensed tannins but not phenolic glycosides or glucose as carbon sources. Growth in nutrient-rich medium was increased by condensed tannins, but reduced by phenolic glycosides. Addition of the P450 enzyme inhibitor piperonyl butoxide increased the effects of phenolic glycosides on Acinetobacter sp. R7-1. In contrast, the esterase inhibitor S,S,S,-tributyl-phosphorotrithioate did not affect phenolic glycoside inhibition of bacterial growth. Degradation of phenolic glycosides by Acinetobacter sp. R7-1 appears to alleviate the cytotoxicity of these compounds, rather than provide an energy source. Our results further suggest this bacterium utilizes additional, complementary mechanisms to degrade antimicrobial phytochemicals. Collectively, these results provide insight into mechanisms by which microorganisms contend with their environment within the context of plant-herbivore interactions.

  4. Developmental contributions to phenotypic variation in functional leaf traits within quaking aspen clones.

    Science.gov (United States)

    Smith, Eric A; Collette, Sean B; Boynton, Thomas A; Lillrose, Tiffany; Stevens, Mikel R; Bekker, Matthew F; Eggett, Dennis; St Clair, Samuel B

    2011-01-01

    Phenotypic variation in plant traits is strongly influenced by genetic and environmental factors. Over the life span of trees, developmental factors may also strongly influence leaf phenotypes. The objective of this study was to fill gaps in our understanding of developmental influences on patterns of phenotypic trait variation among different-aged ramets within quaking aspen (Populus tremuloides Michx.) clones. We hypothesized that phenotypic variation in leaf functional traits is strongly influenced by developmental cues as trees age. We surveyed eight aspen clones, each with eight distinct age classes ranging from 1 to 160 years in age, and selected three ramets per age class for sample collection. Leaf traits measured included photosynthesis, stomatal conductance, water use efficiency, specific leaf area, and concentrations of N, phosphorus, sucrose, starch, condensed tannins and phenolic glycosides. Using regression analysis, we examined the relationships between ramet age and expression of leaf functional traits. The data showed significant correlations between ramet age and 10 of the 12 phenotypic traits measured. Eight of the phenotypic traits demonstrated a non-linear relationship in which large changes in phenotype occurred in the early stages of ramet development and stabilized thereafter. Water relations, nutrient concentration, leaf gas exchange and phenolic glycosides tended to decrease from early to late development, whereas sucrose, condensed tannin concentrations and water use efficiency increased with ramet age. We hypothesize that ontogenetically derived phenotypic variation leads to fitness differentials among different-aged ramets, which may have important implications for clone fitness. Age-related increases in phenotypic diversity may partially underlie aspen's ability to tolerate the large environmental gradients that span its broad geographical range.

  5. Massive mortality of aspen following severe drought along the southern edge of the Canadian boreal forest

    Science.gov (United States)

    Michaelian, Michael; Hogg, Edward H; Hall, Ronald J; Arsenault, Eric

    2011-01-01

    Drought-induced, regional-scale dieback of forests has emerged as a global concern that is expected to escalate under model projections of climate change. Since 2000, drought of unusual severity, extent, and duration has affected large areas of western North America, leading to regional-scale dieback of forests in the southwestern US. We report on drought impacts on forests in a region farther north, encompassing the transition between boreal forest and prairie in western Canada. A central question is the significance of drought as an agent of large-scale tree mortality and its potential future impact on carbon cycling in this cold region. We used a combination of plot-based, meteorological, and remote sensing measures to map and quantify aboveground, dead biomass of trembling aspen (Populus tremuloides Michx.) across an 11.5 Mha survey area where drought was exceptionally severe during 2001–2002. Within this area, a satellite-based land cover map showed that aspen-dominated broadleaf forests occupied 2.3 Mha. Aerial surveys revealed extensive patches of severe mortality (>55%) resembling the impacts of fire. Dead aboveground biomass was estimated at 45 Mt, representing 20% of the total aboveground biomass, based on a spatial interpolation of plot-based measurements. Spatial variation in percentage dead biomass showed a moderately strong correlation with drought severity. In the prairie-like, southern half of the study area where the drought was most severe, 35% of aspen biomass was dead, compared with an estimated 7% dead biomass in the absence of drought. Drought led to an estimated 29 Mt increase in dead biomass across the survey area, corresponding to 14 Mt of potential future carbon emissions following decomposition. Many recent, comparable episodes of drought-induced forest dieback have been reported from around the world, which points to an emerging need for multiscale monitoring approaches to quantify drought effects on woody biomass and carbon cycling

  6. Trade-offs between xylem hydraulic properties, wood anatomy and yield in Populus.

    Science.gov (United States)

    Hajek, Peter; Leuschner, Christoph; Hertel, Dietrich; Delzon, Sylvain; Schuldt, Bernhard

    2014-07-01

    Trees face the dilemma that achieving high plant productivity is accompanied by a risk of drought-induced hydraulic failure due to a trade-off in the trees' vascular system between hydraulic efficiency and safety. By investigating the xylem anatomy of branches and coarse roots, and measuring branch axial hydraulic conductivity and vulnerability to cavitation in 4-year-old field-grown aspen plants of five demes (Populus tremula L. and Populus tremuloides Michx.) differing in growth rate, we tested the hypotheses that (i) demes differ in wood anatomical and hydraulic properties, (ii) hydraulic efficiency and safety are related to xylem anatomical traits, and (iii) aboveground productivity and hydraulic efficiency are negatively correlated to cavitation resistance. Significant deme differences existed in seven of the nine investigated branch-related anatomical and hydraulic traits but only in one of the four coarse-root-related anatomical traits; this likely is a consequence of high intra-plant variation in root morphology and the occurrence of a few 'high-conductivity roots'. Growth rate was positively related to branch hydraulic efficiency (xylem-specific conductivity) but not to cavitation resistance; this indicates that no marked trade-off exists between cavitation resistance and growth. Both branch hydraulic safety and hydraulic efficiency significantly depended on vessel size and were related to the genetic distance between the demes, while the xylem pressure causing 88% loss of hydraulic conductivity (P88 value) was more closely related to hydraulic efficiency than the commonly used P50 value. Deme-specific variation in the pit membrane structure may explain why vessel size was not directly linked to growth rate. We conclude that branch hydraulic efficiency is an important growth-influencing trait in aspen, while the assumed trade-off between productivity and hydraulic safety is weak. © The Author 2014. Published by Oxford University Press. All rights reserved

  7. Innate and introduced resistance traits in genetically modified aspen trees and their effect on leaf beetle feeding.

    Directory of Open Access Journals (Sweden)

    Joakim Hjältén

    Full Text Available Genetic modifications of trees may provide many benefits, e.g. increase production, and mitigate climate change and herbivore impacts on forests. However, genetic modifications sometimes result in unintended effects on innate traits involved in plant-herbivore interactions. The importance of intentional changes in plant defence relative to unintentional changes and the natural variation among clones used in forestry has not been evaluated. By a combination of biochemical measurements and bioassays we investigated if insect feeding on GM aspens is more affected by intentional (induction Bt toxins than of unintentional, non-target changes or clonal differences in innate plant defence. We used two hybrid wildtype clones (Populus tremula x P. tremuloides and Populus tremula x P. alba of aspen that have been genetically modified for 1 insect resistance (two Bt lines or 2 reduced lignin properties (two lines COMT and CAD, respectively. Our measurements of biochemical properties suggest that unintended changes by GM modifications (occurring due to events in the transformation process in innate plant defence (phenolic compounds were generally smaller but fundamentally different than differences seen among different wildtype clones (e.g. quantitative and qualitative, respectively. However, neither clonal differences between the two wildtype clones nor unintended changes in phytochemistry influenced consumption by the leaf beetle (Phratora vitellinae. By contrast, Bt induction had a strong direct intended effect as well as a post experiment effect on leaf beetle consumption. The latter suggested lasting reduction of beetle fitness following Bt exposure that is likely due to intestinal damage suffered by the initial Bt exposure. We conclude that Bt induction clearly have intended effects on a target species. Furthermore, the effect of unintended changes in innate plant defence traits, when they occur, are context dependent and have in comparison to Bt

  8. Influence of stocking, site quality, stand age, low-severity canopy disturbance, and forest composition on sub-boreal aspen mixedwood carbon stocks

    Science.gov (United States)

    Reinikainen, Michael; D’Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Low-severity canopy disturbance presumably influences forest carbon dynamics during the course of stand development, yet the topic has received relatively little attention. This is surprising because of the frequent occurrence of such events and the potential for both the severity and frequency of disturbances to increase as a result of climate change. We investigated the impacts of low-severity canopy disturbance and average insect defoliation on forest carbon stocks and rates of carbon sequestration in mature aspen mixedwood forests of varying stand age (ranging from 61 to 85 years), overstory composition, stocking level, and site quality. Stocking level and site quality positively affected the average annual aboveground tree carbon increment (CAAI), while stocking level, site quality, and stand age positively affected tree carbon stocks (CTREE) and total ecosystem carbon stocks (CTOTAL). Cumulative canopy disturbance (DIST) was reconstructed using dendroecological methods over a 29-year period. DIST was negatively and significantly related to soil carbon (CSOIL), and it was negatively, albeit marginally, related to CTOTAL. Minima in the annual aboveground carbon increment of trees (CAI) occurred at sites during defoliation of aspen (Populus tremuloides Michx.) by forest tent caterpillar (Malacosoma disstria Hubner), and minima were more extreme at sites dominated by trembling aspen than sites mixed with conifers. At sites defoliated by forest tent caterpillar in the early 2000s, increased sequestration by the softwood component (Abies balsamea (L.) Mill. and Picea glauca (Moench) Voss) compensated for overall decreases in CAI by 17% on average. These results underscore the importance of accounting for low-severity canopy disturbance events when developing regional forest carbon models and argue for the restoration and maintenance of historically important conifer species within aspen mixedwoods to enhance stand-level resilience to disturbance agents and maintain

  9. Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

    Science.gov (United States)

    Asko Noormets; Olevi Kull; Anu Sober; Mark E. Kubiske; David F. Karnosky

    2010-01-01

    The effect of elevated CO2 and O3 on apparent quantum yield (ø), maximum photosynthesis (Pmax), carboxylation efficiency (Vcmax) and electron transport capacity (Jmax) at different canopy locations was studied in two aspen (Populus...

  10. Fluxes of CH4 and N2O in aspen stands grown under ambient and twice-ambient CO2

    DEFF Research Database (Denmark)

    Ambus, P.; Robertson, G.P.

    1999-01-01

    Elevated atmospheric CO2 has the potential to change below-ground nutrient cycling and thereby alter the soil-atmosphere exchange of biogenic trace gases. We measured fluxes of CH4 and N2O in trembling aspen (Populus tremuloides Michx.) stands grown in open-top chambers under ambient and twice......-ambient CO2 concentrations crossed with `high' and low soil-N conditions. Flux measurements with small static chambers indicated net CH4 oxidation in the open-top chambers. Across dates, CH4 oxidation activity was significantly (P CO2 (8.7 mu g CH4-C m(-2) h(-1)) than.......05) with twice-ambient CO2 than with ambient CO2. Fluxes of N2O in the open-top chambers and in separate 44 cm(2) cores +/-N fertilization were not affected by CO2 treatment and soil N status. Our data show that elevated atmospheric CO2 may have a negative effect on terrestrial CH4 oxidation. The data also...

  11. Bisphosphonate inhibitors reveal a large elasticity of plastidic isoprenoid synthesis pathway in isoprene-emitting hybrid aspen.

    Science.gov (United States)

    Rasulov, Bahtijor; Talts, Eero; Kännaste, Astrid; Niinemets, Ülo

    2015-06-01

    Recently, a feedback inhibition of the chloroplastic 1-deoxy-D-xylulose 5-phosphate (DXP)/2-C-methyl-D-erythritol 4-phosphate (MEP) pathway of isoprenoid synthesis by end products dimethylallyl diphosphate (DMADP) and isopentenyl diphosphate (IDP) was postulated, but the extent to which DMADP and IDP can build up is not known. We used bisphosphonate inhibitors, alendronate and zoledronate, that inhibit the consumption of DMADP and IDP by prenyltransferases to gain insight into the extent of end product accumulation and possible feedback inhibition in isoprene-emitting hybrid aspen (Populus tremula × Populus tremuloides). A kinetic method based on dark release of isoprene emission at the expense of substrate pools accumulated in light was used to estimate the in vivo pool sizes of DMADP and upstream metabolites. Feeding with fosmidomycin, an inhibitor of DXP reductoisomerase, alone or in combination with bisphosphonates was used to inhibit carbon input into DXP/MEP pathway or both input and output. We observed a major increase in pathway intermediates, 3- to 4-fold, upstream of DMADP in bisphosphonate-inhibited leaves, but the DMADP pool was enhanced much less, 1.3- to 1.5-fold. In combined fosmidomycin/bisphosphonate treatment, pathway intermediates accumulated, reflecting cytosolic flux of intermediates that can be important under strong metabolic pull in physiological conditions. The data suggested that metabolites accumulated upstream of DMADP consist of phosphorylated intermediates and IDP. Slow conversion of the huge pools of intermediates to DMADP was limited by reductive energy supply. These data indicate that the DXP/MEP pathway is extremely elastic, and the presence of a significant pool of phosphorylated intermediates provides an important valve for fine tuning the pathway flux. © 2015 American Society of Plant Biologists. All Rights Reserved.

  12. Aspen Characteristics - Aspen Delineation Project [ds361

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Lake Tahoe Basin Management Unit (Placer and...

  13. Nonstructural carbohydrate remobilization and suckering of aspen roots following severe disturbance

    Science.gov (United States)

    Wiley, E.; King, C.; Richardson, A. D.; Landhäusser, S.

    2016-12-01

    Nonstructural carbohydrate (NSC) storage and remobilization are important processes that allow trees to temporarily maintain a negative carbon balance and recover from disturbances that kill aboveground tissue and/or limit carbon uptake. However, our knowledge of carbohydrate remobilization in trees remains very limited. Recent isotopic work suggests that trees can store carbohydrates that are relatively old, but it is not known how much of this carbon can be remobilized and used for growth. To determine the extent and the spatial/temporal pattern in which carbohydrates are remobilized following a severe disturbance, we collected root segments (1-3 cm diameter; 10-30 years old) from mature trembling aspen (Populus tremuloides Michx.) in northern Alberta. These roots were incubated in a dark growth chamber to ensure that root reserves were the sole supply of carbon for root suckering. Roots were harvested periodically to measure sucker growth and NSC concentrations of the phloem and inner and outer xylem. In addition, at two stages of suckering, the carbon in the newest sucker tissues was aged using the radiocarbon `bomb spike'. Initially, roots contained 5-6 times more NSC mass in the phloem than in the xylem, and the decrease in NSC mass during suckering was 3-4 times greater in the phloem. Root sucker mass was more strongly correlated with initial phloem NSC than xylem NSC concentration. Early sucker growth was composed of relatively young carbon, averaging 1-3 years old. Later sucker growth was significantly, but only slightly older ( 1 yr). At sucker death, xylem still contained 2-3% NSC and phloem contained 11-13.5% NSC; NSC pools were reduced to a greater degree in xylem than in phloem. These results suggest that the phloem—an often overlooked carbohydrate pool—contains a large and important carbon reserve pool for regrowth following disturbance. The high levels of carbohydrates remaining in the root suggest that a large portion of NSC may be unavailable

  14. Circadian patterns of xylem sap properties and their covariation with plant hydraulic traits in hybrid aspen.

    Science.gov (United States)

    Meitern, Annika; Õunapuu-Pikas, Eele; Sellin, Arne

    2017-06-01

    Physiological processes taking place in plants are subject to diverse circadian patterns but some of them are poorly documented in natural conditions. The daily dynamics of physico-chemical properties of xylem sap and their covariation with tree hydraulic traits were investigated in hybrid aspen (Populus tremula L.×P. tremuloides Michx) in field conditions in order to clarify which environmental drivers govern the daily variation in these parameters. K(+) concentration ([K(+)]), electrical conductivity (σsap), osmolality (Osm) and pH of the xylem sap, as well as branch hydraulic traits, were measured in the field over 24-h cycles. All studied xylem sap properties and hydraulic characteristics including whole-branch (Kwb), leaf blade (Klb) and petiole hydraulic conductances (KP) showed clear daily dynamics. Air temperature (TA) and photosynthetic photon flux density (PPFD), but also water vapour pressure deficit (VPD) and relative humidity (RH), had significant impacts on KwbKlb, KP, [K(+)] and σsap. Osm varied only with light intensity, while KB varied depending on atmospheric evaporative demand expressed as TA, VPD or RH. Xylem sap pH depended inversely on soil water potential (ΨS) and during daylight also on VPD. Although soil water content was close to saturation during the study period, ΨS influenced also [K(+)] and σsap. The present study presents evidence of coupling between circadian patterns of xylem sap properties and plant hydraulic conductance providing adequate water supply to foliage under environmental conditions characterised by diurnal variation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  15. Expression of a fungal glucuronoyl esterase in Populus: effects on wood properties and saccharification efficiency.

    Science.gov (United States)

    Latha Gandla, Madhavi; Derba-Maceluch, Marta; Liu, Xiaokun; Gerber, Lorenz; Master, Emma R; Mellerowicz, Ewa J; Jönsson, Leif J

    2015-04-01

    The secondary walls of angiosperms contain large amounts of glucuronoxylan that is thought to be covalently linked to lignin via ester bonds between 4-O-methyl-α-D-glucuronic acid (4-O-Me-GlcA) moieties in glucuronoxylan and alcohol groups in lignin. This linkage is proposed to be hydrolysed by glucuronoyl esterases (GCEs) secreted by wood-degrading fungi. We report effects of overexpression of a GCE from the white-rot basidiomycete Phanerochaete carnosa, PcGCE, in hybrid aspen (Populus tremula L. x tremuloides Michx.) on the wood composition and the saccharification efficiency. The recombinant enzyme, which was targeted to the plant cell wall using the signal peptide from hybrid aspen cellulase PttCel9B3, was constitutively expressed resulting in the appearance of GCE activity in protein extracts from developing wood. Diffuse reflectance FT-IR spectroscopy and pyrolysis-GC/MS analyses showed significant alternation in wood chemistry of transgenic plants including an increase in lignin content and S/G ratio, and a decrease in carbohydrate content. Sequential wood extractions confirmed a massive (+43%) increase of Klason lignin, which was accompanied by a ca. 5% decrease in cellulose, and ca. 20% decrease in wood extractives. Analysis of the monosaccharide composition using methanolysis showed a reduction of 4-O-Me-GlcA content without a change in Xyl contents in transgenic lines, suggesting that the covalent links between 4-O-Me-GlcA moieties and lignin protect these moieties from degradation. Enzymatic saccharification without pretreatment resulted in significant decreases of the yields of Gal, Glc, Xyl and Man in transgenic lines, consistent with their increased recalcitrance caused by the increased lignin content. In contrast, the enzymatic saccharification after acid pretreatment resulted in Glc yields similar to wild-type despite of their lower cellulose content. These data indicate that whereas PcGCE expression in hybrid aspen increases lignin deposition

  16. Dicty_cDB: SSE645 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available um cDNA library Populus tremula x Populus tremuloides cDNA, mRNA sequence. 56 5e-04 1 CA929873 |CA929873.1 MTU2CA.P3.H06 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 56 5e-04 1 CA929744 |CA929744.1 MTU2CA.P2.B05 Aspen ape...56 5e-04 1 CA929228 |CA929228.1 MTU2CA.P10.G09 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequen

  17. Responses of sap flow, leaf gas exchange and growth of hybrid aspen to elevated atmospheric humidity under field conditions.

    Science.gov (United States)

    Niglas, Aigar; Kupper, Priit; Tullus, Arvo; Sellin, Arne

    2014-05-15

    An increase in average air temperature and frequency of rain events is predicted for higher latitudes by the end of the 21st century, accompanied by a probable rise in air humidity. We currently lack knowledge on how forest trees acclimate to rising air humidity in temperate climates. We analysed the leaf gas exchange, sap flow and growth characteristics of hybrid aspen (Populus tremula × P. tremuloides) trees growing at ambient and artificially elevated air humidity in an experimental forest plantation situated in the hemiboreal vegetation zone. Humidification manipulation did not affect the photosynthetic capacity of plants, but did affect stomatal responses: trees growing at elevated air humidity had higher stomatal conductance at saturating photosynthetically active radiation (gs sat) and lower intrinsic water-use efficiency (IWUE). Reduced stomatal limitation of photosynthesis in trees grown at elevated air humidity allowed slightly higher net photosynthesis and relative current-year height increments than in trees at ambient air humidity. Tree responses suggest a mitigating effect of higher air humidity on trees under mild water stress. At the same time, trees at higher air humidity demonstrated a reduced sensitivity of IWUE to factors inducing stomatal closure and a steeper decline in canopy conductance in response to water deficit, implying higher dehydration risk. Despite the mitigating impact of increased air humidity under moderate drought, a future rise in atmospheric humidity at high latitudes may be disadvantageous for trees during weather extremes and represents a potential threat in hemiboreal forest ecosystems. Published by Oxford University Press on behalf of the Annals of Botany Company.

  18. Hypoxylon Canker of Aspen

    Science.gov (United States)

    Ralph L. Anderson; Gerald W. Anderson; Arthur L. Jr. Schipper

    1979-01-01

    Hypoxylon canker, caused by the fungus Hypoxylon mammatum (Wahl.) Mill. (formerly H. pruinatum (Klot.) Cke.), is one of the most important killing diseases of aspen in eastern North America. In Michigan, Minnesota, and Wisconsin, the total impact of Hypoxylon canker has been estimated to be 30 percent of the annual net growth of aspen; in 1972, trees worth more than $4...

  19. Selecting Populus with different adventitious root types for environmental benefits, fiber, and energy

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Jill A. Zalesny

    2009-01-01

    Primary roots from seeds, sucker roots in aspens, and adventitious roots (ARs) in poplars and their hybrids are prevalent within the genus Populus. Two AR types develop on hardwood cuttings: (i) lateral roots from either preformed or induced primordia along the length of the cutting and (ii) basal roots from callus at the base of the cutting in...

  20. Leaf chemical composition of twenty-one Populus hybrid clones grown under intensive culture

    Science.gov (United States)

    Richard E. Dickson; Philip R. Larson

    1976-01-01

    Leaf material from 21 nursery-grown Populus hybrid clones was analyzed for three nitrogen fractions (total N, soluble protein, and soluble amino acids) and three carbhydrate fractions (reducing sugars, total soluble sugars, and total nonstructural carbohydrates-TNC). In addition, nursery-grown green ash and silver maple, field-grown bigtooth and trembling aspen, and...

  1. Dicty_cDB: VFC716 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 0.32 2 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. ...34 0.84 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequenc

  2. Dicty_cDB: SHJ263 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available A, mRNA sequence. 44 3.7 1 CA929806 |CA929806.1 MTU2CA.P3.A01 Aspen apex cDNA Library Populus tremuloides cD...NA, mRNA sequence. 44 3.7 1 CA929196 |CA929196.1 MTU2CA.P10.C05 Aspen apex cDNA Library Populus tremuloides

  3. Dicty_cDB: VSD543 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA seque...nce. 34 0.78 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA se

  4. Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species.

    Science.gov (United States)

    Du, Shuhui; Wang, Zhaoshan; Ingvarsson, Pär K; Wang, Dongsheng; Wang, Junhui; Wu, Zhiqiang; Tembrock, Luke R; Zhang, Jianguo

    2015-10-01

    Historical tectonism and climate oscillations can isolate and contract the geographical distributions of many plant species, and they are even known to trigger species divergence and ultimately speciation. Here, we estimated the nucleotide variation and speciation in three closely related Populus species, Populus tremuloides, P. tremula and P. davidiana, distributed in North America and Eurasia. We analysed the sequence variation in six single-copy nuclear loci and three chloroplast (cpDNA) fragments in 497 individuals sampled from 33 populations of these three species across their geographic distributions. These three Populus species harboured relatively high levels of nucleotide diversity and showed high levels of nucleotide differentiation. Phylogenetic analysis revealed that P. tremuloides diverged earlier than the other two species. The cpDNA haplotype network result clearly illustrated the dispersal route from North America to eastern Asia and then into Europe. Molecular dating results confirmed that the divergence of these three species coincided with the sundering of the Bering land bridge in the late Miocene and a rapid uplift of the Qinghai-Tibetan Plateau around the Miocene/Pliocene boundary. Vicariance-driven successful allopatric speciation resulting from historical tectonism and climate oscillations most likely played roles in the formation of the disjunct distributions and divergence of these three Populus species. © 2015 John Wiley & Sons Ltd.

  5. The influence of chemistry, production and community composition under elevated atmospheric CO2 and tropospheric O3 in a northern hardwood ecosystem

    Science.gov (United States)

    Lingli Liu; John S. King; Christian P. Giardina; Fitzgerald L. Booker

    2009-01-01

    We examined the effects of elevated CO2 and O3 and their interaction on leaf litter chemistry and decomposition in pure stands of aspen (Populus tremuloides) and mixed stands of birch (Betula papyrifera) and aspen at the Aspen Free Air CO2 Enrichment (FACE) experiment. A 935-day in situ incubation...

  6. Uptake and partitioning of simulated atmospheric N inputs in Populus Tremuloides - Pinus Strobus forest mesocosms

    Energy Technology Data Exchange (ETDEWEB)

    Nave, Lucas E.; Curtis, Peter S.

    2011-06-15

    This study looked at the effect of Nitrogen (N) inputs on forest growth and carbon storage by studying the relationship between N deposition, tree N uptake and growth. A 15N tracer was used to quantify foliar and root uptake of N deposition by trees; results showed that trees are a small short term sink for N inputs and thus these inputs do not have an important impacts on forest biomass N content or net primary productivity on a short term. .

  7. ASPEN Version 3.0

    Science.gov (United States)

    Rabideau, Gregg; Chien, Steve; Knight, Russell; Schaffer, Steven; Tran, Daniel; Cichy, Benjamin; Sherwood, Robert

    2006-01-01

    The Automated Scheduling and Planning Environment (ASPEN) computer program has been updated to version 3.0. ASPEN is a modular, reconfigurable, application software framework for solving batch problems that involve reasoning about time, activities, states, and resources. Applications of ASPEN can include planning spacecraft missions, scheduling of personnel, and managing supply chains, inventories, and production lines. ASPEN 3.0 can be customized for a wide range of applications and for a variety of computing environments that include various central processing units and random access memories.

  8. Dicty_cDB: VSJ730 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 12 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloid...es cDNA, mRNA sequence. 34 0.76 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremul...oides cDNA, mRNA sequence. 34 0.76 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Library Populus tre...muloides cDNA, mRNA sequence. 34 0.76 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  9. Aspen Delineation - Inyo National Forest [ds366

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands where aspen assessments were collected in the Inyo National Forest, Inyo County, California. The Inyo...

  10. Aspen Delineation - Klamath National Forest [ds370

    Data.gov (United States)

    California Department of Resources — The database represents polygons of aspen stands in the Klamath National Forest, Siskiyou County, California. The Klamath National Forest Region 5 Vegetation aspen...

  11. The Impact of Nitrogen Limitation and Mycorrhizal Symbiosis on Aspen Tree Growth and Development

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Bich Thi Ngoc [Univ. of Alabama, Huntsville, AL (United States)

    2014-08-18

    Nitrogen deficiency is the most common and widespread nutritional deficiency affecting plants worldwide. Ectromycorrhizal symbiosis involves the beneficial interaction of plants with soil fungi and plays a critical role in nutrient cycling, including the uptake of nitrogen from the environment. The main goal of this study is to understand how limiting nitrogen in the presence or absence of an ectomycorrhizal fungi, Laccaria bicolor, affects the health of aspen trees, Populus temuloides.

  12. Cankers on Western Quaking Aspen

    Science.gov (United States)

    David W. Johnson; Jerome S. Beatty; Thomas E. Hinds

    1995-01-01

    Long appreciated for its esthetic and shade tree value and its importance for wildlife, aspen is also capable of excellent growth and high yields and thus is an important commercial timber species. However, aspen has one major drawback-its soft bark is easily wounded by abiotic factors, animals, and insects. Subsequently, these wounds can be invaded by disease...

  13. Manipulations to regenerate aspen ecosystems

    Science.gov (United States)

    Wayne D. Shepperd

    2001-01-01

    Vegetative regeneration of aspen can be initiated through manipulations that provide hormonal stimulation, proper growth environment, and sucker protection - the three elements of the aspen regeneration triangle. The correct course of action depends upon a careful evaluation of the size, vigor, age, and successional status of the existing clone. Soils and site...

  14. Contrasting patterns of cytokinins between years in senescing aspen leaves.

    Science.gov (United States)

    Edlund, Erik; Novak, Ondrej; Karady, Michal; Ljung, Karin; Jansson, Stefan

    2017-05-01

    Cytokinins are plant hormones that typically block or delay leaf senescence. We profiled 34 different cytokinins/cytokinin metabolites (including precursors, conjugates and degradation products) in leaves of a free-growing mature aspen (Populus tremula) before and after the initiation of autumnal senescence over three consecutive years. The levels and profiles of individual cytokinin species, or classes/groups, varied greatly between years, despite the fact that the onset of autumn senescence was at the same time each year, and senescence was not associated with depletion of either active or total cytokinin levels. Levels of aromatic cytokinins (topolins) were low and changed little over the autumn period. Diurnal variations and weather-dependent variations in cytokinin content were relatively limited. We also followed the expression patterns of all aspen genes implicated as having roles in cytokinin metabolism or signalling, but neither the pattern of regulation of any group of genes nor the expression of any particular gene supported the notion that decreased cytokinin signalling could explain the onset of senescence. Based on the results from this tree, we therefore suggest that cytokinin depletion is unlikely to explain the onset of autumn leaf senescence in aspen. © 2017 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.

  15. Dicty_cDB: VSC814 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.18... 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0....18 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. 3...4 0.18 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex cDNA Library Populus trem

  16. Establishment of alleycropped hybrid aspen "Crandon" in central Iowa, USA: effects of topographic position and fertilizer rate on above ground biomass production and allocation

    Science.gov (United States)

    William L. Headlee; Richard B. Hall; Ronald S., Jr. Zalesny

    2013-01-01

    Hybrid poplars have demonstrated high productivity as short rotation woody crops (SRWC) in the Midwest USA, and the hybrid aspen "Crandon" (Populus alba L. × P. grandidenta Michx.) has exhibited particularly promising yields on marginal lands. However, a key obstacle for wider deployment is the lack of economic...

  17. The role of phytochrome A and gibberellins in growth under long and short day conditions: Studies in hybrid aspen

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, M.E. [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Forest Genetics and Plant Physiology

    2000-07-01

    This thesis addresses questions concerning the regulation of growth and, specifically, the cessation of growth in response to short days in deciduous tree species. The model tree used in the studies was hybrid aspen (Populus tremula L. x P. tremuloides Michx.). We have exploited the possibility of transforming this species to modulate the level of expression of target genes using over-expression and antisense techniques. The target genes in the studies were the photoreceptor phytochrome A (phyA) and gibberellin 20-oxidase (GA 20-oxidase), the latter being a highly regulated enzyme involved in the biosynthesis of gibberellins (GAs). The photoreceptor phyA has been implicated in photoperiodic regulation of growth, while GAs may regulate the physiological response further downstream. The endogenous expression of these genes has been investigated in parallel with studies of various plants with ectopic and reduced levels of expression. The main focus has been on the early stages of induction of growth cessation and its physiological and molecular mechanisms. Studies of hybrid aspen plants with an increased or reduced expression of phyA, show this receptor to mediate the photoperiodic regulation of growth. Plants with ectopic expression could not stop growing despite drastically shortened photoperiods, while the antisense plants showed the reverse phenotype, with a higher sensitivity resulting in earlier cessation of growth. The role of GAs in growth inhibition was also addressed using plants with a reduction in GA levels. These plants showed early cessation of growth and dormancy, and thus an increased sensitivity toward daylength. Conversely, plants with increased rates of GA biosynthesis showed increased growth and stopped growing much later. Furthermore, increases in GA biosynthesis, resulting in high levels of GAs have a major impact on growth. Plants with high GA levels have increased elongation and diameter growth, due to higher rates of cell production in the

  18. Gibberellins inhibit adventitious rooting in hybrid aspen and Arabidopsis by affecting auxin transport.

    Science.gov (United States)

    Mauriat, Mélanie; Petterle, Anna; Bellini, Catherine; Moritz, Thomas

    2014-05-01

    Knowledge of processes involved in adventitious rooting is important to improve both fundamental understanding of plant physiology and the propagation of numerous plants. Hybrid aspen (Populus tremula × tremuloïdes) plants overexpressing a key gibberellin (GA) biosynthesis gene (AtGA20ox1) grow rapidly but have poor rooting efficiency, which restricts their clonal propagation. Therefore, we investigated the molecular basis of adventitious rooting in Populus and the model plant Arabidopsis. The production of adventitious roots (ARs) in tree cuttings is initiated from the basal stem region, and involves the interplay of several endogenous and exogenous factors. The roles of several hormones in this process have been characterized, but the effects of GAs have not been fully investigated. Here, we show that a GA treatment negatively affects the numbers of ARs produced by wild-type hybrid aspen cuttings. Furthermore, both hybrid aspen plants and intact Arabidopsis seedlings overexpressing AtGA20ox1, PttGID1.1 or PttGID1.3 genes (with a 35S promoter) produce few ARs, although ARs develop from the basal stem region of hybrid aspen and the hypocotyl of Arabidopsis. In Arabidopsis, auxin and strigolactones are known to affect AR formation. Our data show that the inhibitory effect of GA treatment on adventitious rooting is not mediated by perturbation of the auxin signalling pathway, or of the strigolactone biosynthetic and signalling pathways. Instead, GAs appear to act by perturbing polar auxin transport, in particular auxin efflux in hybrid aspen, and both efflux and influx in Arabidopsis. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  19. Dicty_cDB: VSC792 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ens chromosome , clone RP11-102L12, complete sequence. 44 0.18 5 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.32 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex...CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.32 2 CA93057...7 |CA930577.1 MTU4CA.P24.B11 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.32 2 AC12

  20. Dicty_cDB: VSI729 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 12, complete sequence. 44 0.30 4 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremulo...ides cDNA, mRNA sequence. 34 0.34 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.34 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.34 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  1. Dicty_cDB: VSC403 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available to spore germination protein. 86 2e-21 3 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.17 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.17 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.17 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  2. Dicty_cDB: VSK377 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available te sequence. 44 0.32 6 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA,... mRNA sequence. 34 0.53 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremuloides cD...NA, mRNA sequence. 34 0.53 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA ...Library Populus tremuloides cDNA, mRNA sequence. 34 0.53 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex cD

  3. Dicty_cDB: VSE526 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available clone RP11-102L12, complete sequence. 44 0.18 5 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library... Populus tremuloides cDNA, mRNA sequence. 34 0.31 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Libr...ary Populus tremuloides cDNA, mRNA sequence. 34 0.31 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.32 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  4. Dicty_cDB: VSC225 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA se...quence. 34 0.29 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA... sequence. 34 0.29 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Library Populus tremuloides cDNA, m...RNA sequence. 34 0.30 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex cDNA Libra

  5. Dicty_cDB: [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available lete cds. 78 2e-22 3 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA, m...RNA sequence. 34 0.43 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library Populus tremuloides cDNA..., mRNA sequence. 34 0.43 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Li...brary Populus tremuloides cDNA, mRNA sequence. 34 0.43 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex cDNA

  6. Dicty_cDB: VSA635 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available m mRNA for unknown protein with homology to spore germination protein. 86 5e-41 5 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.37 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex...0.37 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. ...34 0.37 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequenc

  7. Dicty_cDB: VSB172 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available tion protein. 86 4e-28 3 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDN...A, mRNA sequence. 34 0.27 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA L...ibrary Populus tremuloides cDNA, mRNA sequence. 34 0.27 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDN...A Library Populus tremuloides cDNA, mRNA sequence. 34 0.27 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  8. Dicty_cDB: SSI586 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available quence. 44 0.23 5 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA... sequence. 34 0.35 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex cDNA Library ...Populus tremuloides cDNA, mRNA sequence. 34 0.35 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex cDNA Libra...ry Populus tremuloides cDNA, mRNA sequence. 34 0.35 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex cDNA Li

  9. Dicty_cDB: SSI291 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available one RP11-102L12, complete sequence. 44 0.23 6 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Po...pulus tremuloides cDNA, mRNA sequence. 34 0.46 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.46 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.46 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  10. Dicty_cDB: VSJ788 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available in AX4, complete sequence. 34 0.55 12 CA930567 |CA930567.1 MTU4CA.P24.B01 Aspen apex cDNA Library Populus tr...emuloides cDNA, mRNA sequence. 34 0.79 2 CA930485 |CA930485.1 MTU4CA.P23.B04 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.79 2 CA930468 |CA930468.1 MTU4CA.P22.H11 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 34 0.79 2 CA930577 |CA930577.1 MTU4CA.P24.B11 Aspen apex

  11. 1990 sampling of treated aspen stands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In mid-August, 1990, sampling of aspen stand exclosures were conducted at the National Elk Refuge. This sampling is part of a study to monitor aspen regeneration on...

  12. Aspen Delineation - Plumas National Forest [ds374

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_PTS) collected in aspen stands in the Plumas National Forest,...

  13. Aspen Delineation - Sierra State Parks [ds380

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SIERRA_SP_PTS) collected in aspen stands on lands administered by the...

  14. Aspen Delineation - Lassen National Forest [ds372

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (LASSEN_NF_EAGLELAKE_PTS) collected in aspen stands in the in the Eagle...

  15. Aspen Delineation - Sequoia National Forest [ds378

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SEQUOIA_NF_PTS) collected in aspen stands in the Cannell Meadows Ranger...

  16. Dicty_cDB: CHS348 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available RNA sequence. 44 6.2 1 CA929806 |CA929806.1 MTU2CA.P3.A01 Aspen apex cDNA Library Populus tremuloides cDNA, ...mRNA sequence. 44 6.2 1 CA929196 |CA929196.1 MTU2CA.P10.C05 Aspen apex cDNA Libra

  17. Isolation and Culture of Leaf Protoplasts from In Vitro Subcultured Poplars: Populus tomentosa, Populus alba cv. Pyramidalis×Populus tomentosa and Populus maximowiczii×Populus plantierensis

    OpenAIRE

    KANG, Jae-Myung; IDE, Yuji; SASAKI, Satohiko

    1995-01-01

    Leaf protolasts were successfully isolated from in vitro cultured plantlets of Populus tomentosa, Populus alba cv. Pyramidalis×Populus tomentosa and Populus maximowiczii×Populus plantierensis by using enzyme solution containing 1% Cellulase 'Onozuka'RS and 0.25% Pectolyase Y-23 in 0.6M mannitol solution. Cell division and cell cluster formation were observed in P. maximowiczii×P. plantierensis during successive culture in a modified MS liquid medium containing BAP and 2,4-D, from which ammoni...

  18. Management of aspen in a changing environment

    Science.gov (United States)

    Shinneman, Douglas; Halford, Anne S.; Howell, Cheri; Krasnow, Kevin D.; Strand, Eva K.; Chambers, Jeanne

    2015-01-01

    Aspen communities are biologically rich and ecologically valuable, yet they face myriad threats, including changing climate, altered fire regimes, and excessive browsing by domestic and wild ungulates. Recognizing the different types of aspen communities that occur in the Great Basin, and being able to distinguish between seral and stable aspen stands, can help managers better identify restoration needs and objectives. Identifying key threats to aspen regeneration and persistence in a given stand or landscape is important to designing restoration plans, and to selecting appropriate treatment types. Although some aspen stands will need intensive treatment (e.g., use of fire) to persist or remain healthy, other stands may only require the modification of current management practices (e.g., reducing livestock browsing) or may not require any action at all (e.g., self-replacing stable aspen communities).

  19. Aspen Characteristics - Plumas National Forest [ds373

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Beckwourth Ranger District...

  20. Aspen Characteristics - Sierra State Parks [ds379

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands on lands administrated by the Sierra District, California...

  1. Aspen Characteristics - Klamath National Forest [ds369

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected with known aspen stands in the Klamath National Forest, Siskiyou County,...

  2. Aspen Characteristics - Sequoia National Forest [ds377

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Cannell Meadows Ranger District, Sequoia National...

  3. Aspen Delineation - El Dorado National Forest [ds364

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands, where aspen assessments were gathered in the Eldorado National Forest, Eldorado and Amador Counties,...

  4. Aspen Delineation - Klamath National Forest, EUI [ds368

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands where aspen assessments were collected in the Klamath National Forest, Siskiyou County, California. The...

  5. Effectiveness of mycorrhizal inoculation in the nursery on root colonization, growth, and nutrient uptake of aspen and balsam poplar

    Energy Technology Data Exchange (ETDEWEB)

    Quoreshi, A.M.; Khasa, D.P. [Symbiotech Research Inc. 201, 509-11 Avenue, Nisku, AB (Canada); Forest Biology Research Centre, University of Laval, Quebec (Canada)

    2008-05-15

    Aspen and balsam poplar seedlings were inoculated with six species of ectomycorrhizal fungi (Hebeloma longicaudum, Laccaria bicolor, Paxillus involutus, Pisolithus tinctorius, Rhizopogon vinicolor, and Suillus tomentosus), one species of endomycorrhizal fungus (Glomus intraradices), two species of bacteria (Agrobacterium sp. and Burkholderia cepacia), treated with a growth hormone (SR3), and co-inoculated with a combination of Paxillus and Burkholderia. The seedlings were grown in a greenhouse under three different fertility regimes. Bacterial inoculation alone did not affect seedling growth and nutrition as observed when co-inoculated with ectomycorrhizal fungus. The biomass and root collar diameter of aspen and balsam poplar were significantly increased when adequate mycorrhizas are formed and more prominent when co-inoculated with P. involutus and B. cepacia and grown at the 67% fertilizer level. Except for R. vinicolor and S. tomentosus, the other four species of ectomycorrhizal fungi and G. intraradices formed symbiotic associations with both plant species. Both ectomycorrhizal and endomycorrhizal colonization were observed at all fertilizer levels and fertilizer applications did not affect the colonization rates. Nitrogen and phosphorus concentrations were significantly improved in both aspen and balsam poplar compared with control only when co-inoculated with P. involutus and B. cepacia. However, plant net nitrogen uptake (content) increased significantly in all successful inoculation treatments and co-inoculated treatment when compared with control. These results hold promise for incorporation of inoculation of Populus sp. with appropriate mycorrhizal fungi and selected bacteria into commercial nursery system to improve the establishment of Populus in various sites. (author)

  6. Natural Selection and Recombination Rate Variation Shape Nucleotide Polymorphism Across the Genomes of Three Related Populus Species.

    Science.gov (United States)

    Wang, Jing; Street, Nathaniel R; Scofield, Douglas G; Ingvarsson, Pär K

    2016-03-01

    A central aim of evolutionary genomics is to identify the relative roles that various evolutionary forces have played in generating and shaping genetic variation within and among species. Here we use whole-genome resequencing data to characterize and compare genome-wide patterns of nucleotide polymorphism, site frequency spectrum, and population-scaled recombination rates in three species of Populus: Populus tremula, P. tremuloides, and P. trichocarpa. We find that P. tremuloides has the highest level of genome-wide variation, skewed allele frequencies, and population-scaled recombination rates, whereas P. trichocarpa harbors the lowest. Our findings highlight multiple lines of evidence suggesting that natural selection, due to both purifying and positive selection, has widely shaped patterns of nucleotide polymorphism at linked neutral sites in all three species. Differences in effective population sizes and rates of recombination largely explain the disparate magnitudes and signatures of linked selection that we observe among species. The present work provides the first phylogenetic comparative study on a genome-wide scale in forest trees. This information will also improve our ability to understand how various evolutionary forces have interacted to influence genome evolution among related species. Copyright © 2016 by the Genetics Society of America.

  7. Chemistry and decomposition of litter from Populus tremuloides Michaux grown at elevated atmospheric CO2and varying N availability

    Science.gov (United States)

    John S. King; Kurt S. Pregitzer; Donald R. Zak; Mark E. Kubiske; Jennifer A. Ashby; William E. Holmes

    2001-01-01

    It has been hypothesized that greater production of total nonstructural carbohydrates (TNC) in foliage grown under elevated atmospheric carbon dioxide (CO2) will result in higher concentrations of defensive compounds in tree leaf litter, possibly leading to reduced rates of decomposition and nutrient cycling in forest ecosystems of the future....

  8. Association of Pinus banksiana Lamb. and Populus tremuloides Michx. seedling fine roots with Sistotrema brinkmannii (Bres.) J. Erikss. (Basidiomycotina)

    Science.gov (United States)

    Lynette R. Potvin; Dana L. Richter; Martin F. Jurgensen; R. Kasten. Dumroese

    2012-01-01

    Sistotrema brinkmannii (Bres.) J. Erikss. (Basidiomycotina, Hydanaceae), commonly regarded as a wood decay fungus, was consistently isolated from bareroot nursery Pinus banksiana Lamb. seedlings. S. brinkmannii was found in ectomycorrhizae formed by Thelephora terrestris Ehrh., ...

  9. Ethanol production from poplar wood through enzymatic saccharification and fermentation by dilute acid and SPORL pretreatments

    Science.gov (United States)

    Z.J. Wang; J.Y. Zhu; Ronald S. Jr. Zalesny; K.F. Chen

    2012-05-01

    Dilute acid (DA) and Sulfite Pretreatment to Overcome Recalcitrance of Lignocelluloses (SPORL) pretreatments were directly applied to wood chips of four poplar wood samples of different genotypes (hereafter referred to as poplars; Populus tremuloides Michx. ‘native aspen collection’; Populus deltoides Bartr. ex Marsh x Populus nigra L. ‘NE222’ and ‘DN5’; P. nigra x...

  10. Prescribed fire, elk, and aspen in Grand Teton National Park

    Science.gov (United States)

    Ron Steffens; Diane Abendroth

    2001-01-01

    In Grand Teton National Park, a landscape-scale assessment of regeneration in aspen has assisted park managers in identifying aspen stands that may be at risk due to a number of interrelated factors, including ungulate browsing and suppression of wildland fire. The initial aspen survey sampled an estimated 20 percent of the park's aspen stands. Assessment of these...

  11. Populus (Salicaceae plantations

    Directory of Open Access Journals (Sweden)

    Gonzalo M. Romano

    2013-01-01

    Full Text Available Aunque los cultivos forestales son comunidades artificiales, modifican condiciones ambientales que pueden alterar la diversidad fúngica nativa. Se estudiaron los efectos del manejo forestal de una plantación de sauces (Salix y álamos (Populus sobre la biodiversidad de Agaromycetes durante un año en una isla del Delta del Paraná, Argentina. Se midieron el peso seco y el número de basidiomas. Se identificaron 28 especies pertenecientes a los Agaricomycetes: 26 especies de Agaricales, una de Polyporales y una de Russulales. Nuestros resultados sugieren que el manejo forestal de dicha plantación no afecta la abundancia ni la diversidad de basidiomas de Agaricomycetes.

  12. Dicty_cDB: FCL-AD09 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 6pz 5', mRNA sequence. 46 3e-05 2 CA932061 |CA932061.1 MTU4TA.P26.D08 Aspen apex cDNA Library Populus tremul...oides cDNA, mRNA sequence. 60 4e-05 1 CA931907 |CA931907.1 MTU4TA.P24.D10 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 60 4e-05 1 CA931766 |CA931766.1 MTU4TA.P22.F10 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 60 4e-05 1 CA931118 |CA931118.1 MTU2TA.P2.D07 Aspen apex...599 |CA931599.1 MTU2TA.P9.E04 Aspen apex cDNA Library Populus tremuloides cDNA, mRNA sequence. 60 4e-05 1 CA

  13. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Directory of Open Access Journals (Sweden)

    Anna Oldén

    Full Text Available Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L. retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old

  14. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Science.gov (United States)

    Oldén, Anna; Ovaskainen, Otso; Kotiaho, Janne S; Laaka-Lindberg, Sanna; Halme, Panu

    2014-01-01

    Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L.) retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered) and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old-growth forests.

  15. Adapting ASPEN for Orbital Express

    Science.gov (United States)

    Chouinard, Caroline; Tran, Daniel; Jones, Grailing; Dang, Van; Knight, Russell

    2010-01-01

    By studying the Orbital Express mission, modeling the spacecraft and scenarios, and testing the system, a technique has been developed that uses recursive decomposition to represent procedural actions declaratively, schema-level uncertainty reasoning to make uncertainty reasoning tractable, and lightweight, natural language processing to automatically parse procedures to produce declarative models. Schema-level uncertainty reasoning has, at its core, the basic assumption that certain variables are uncertain, but not independent. Once any are known, then the others become known. This is important where a variable is uncertain for an action and many actions of the same type exist in the plan. For example, if the number of retries to purge pump lines was unknown (but bounded), and each attempt required a sub-plan, then, once the correct number of attempts required for a purge was known, it would likely be the same for all subsequent purges. This greatly reduces the space of plans that needs to be searched to ensure that all executions are feasible. To accommodate changing scenario procedures, each is ingested into a tabular format in temporal order, and a simple natural-language parser is used to read each step and to derive the impact of that step on memory, power, and communications. Then an ASPEN (Activity Scheduling and Planning Environment) model is produced based on this analysis. The model is tested and further changed by hand, if necessary, to reflect the actual procedure. This results in a great savings of time used for modeling procedures. Many processes that need to be modeled in ASPEN (a declarative system) are, in fact, procedural. ASPEN includes the ability to model activities in a hierarchical fashion, but this representation breaks down if there is a practically unbounded number of sub-activities and decomposition topologies. However, if recursive decomposition is allowed, HTN-like encodings are enabled to represent most procedural phenomena. For

  16. Aspen Characteristics - Lassen National Forest [ds371

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected in aspen stands in the in the Eagle Lake Ranger District, Lassen National...

  17. Biomass of Sacrificed Spruce/Aspen (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Dimension analysis (diameter at breast high, tree height, depth of crown), estimated leaf area, and total aboveground biomass for sacrificed spruce and aspens in...

  18. Populus deltoides Bartr ex Marsh.

    Science.gov (United States)

    D. T. Cooper

    1980-01-01

    Eastern cottonwood (Populus deltoides), one of the largest eastern hardwoods, is short-lived but the fastest-growing commercial forest species in North America. It grows best on moist well-drained sands or silts near streams, often in pure stands. The lightweight, rather soft wood is used primarily for core stock in manufacturing fumiture and for pulpwood. Eastern...

  19. Aspen Delineation - Plumas National Forest, FRRD [ds376

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_FEATHERRIVER_PTS) collected in aspen stands in the Plumas...

  20. Interannual climatic variation mediates elevated CO2 and O3 effects on forest growth

    Science.gov (United States)

    Mark E. Kubiske; Vanessa A. Quinn; Warren E. Heilman; Evan P. McDonald; Paula E. Marquardt; Ron M. Teclaw; Alexander L. Friend; David F. Karnosky

    2006-01-01

    We analyzed growth data from model aspen (Populus tremuloides Michx.) forest ecosystems grown in elevated atmospheric carbon dioxide ([CO2]; 518?LL-1) and ozone concentrations ([O3]; 1.5 x background of 30-40 nL L-1 during daylight hours) for 7 years using...

  1. Stacked propagation: a new way to grow native plants from root cuttings

    Science.gov (United States)

    David R. Dreesen; Thomas D. Landis; Jeremy R. Pinto

    2006-01-01

    Stacked propagation is a novel method of growing quaking aspen (Populus tremuloides Michx. [Salicaceae]) and other plants that reproduce from underground stems or root cuttings. Because the mother plant is not damaged, it is particularly well suited for rare plants or those that can’t be propagated by normal methods. Our initial trials indicate that...

  2. Fluid dynamics structures in a fire environment observed in laboratory-scale experiments

    Science.gov (United States)

    J. Lozano; W. Tachajapong; D.R. Weise; S. Mahalingam; M. Princevac

    2010-01-01

    Particle Image Velocimetry (PIV) measurements were performed in laboratory-scale experimental fires spreading across horizontal fuel beds composed of aspen (Populus tremuloides Michx) excelsior. The continuous flame, intermittent flame, and thermal plume regions of a fire were investigated. Utilizing a PIV system, instantaneous velocity fields for...

  3. Root-associated ectomycorrhizal fungi shared by various boreal forest seedlings naturally regenerating after a fire in interior Alaska and correlation of different fungi with host growth responses

    Science.gov (United States)

    Elizabeth Bent; Preston Kiekel; Rebecca Brenton; D.Lee. Taylor

    2011-01-01

    The role of common mycorrhizal networks (CMNs) in postfire boreal forest successional trajectories is unknown. We investigated this issue by sampling a 50-m by 40-m area of naturally regenerating black spruce (Picea mariana), trembling aspen, (Populus tremuloides), and paper birch (Betula papyrifera)...

  4. Flammulated Owls (Otus flammeolus) breeding in deciduous forests

    Science.gov (United States)

    Carl D. Marti

    1997-01-01

    The first studies of nesting Flammulated Owls (Otus flammeolus) established the idea that the species needs ponderosa pine (Pinus ponderosa) forests for breeding. In northern Utah, Flammulated Owls nested in montane deciduous forests dominated by quaking aspen (Populus tremuloides). No pines were present but...

  5. Site Investigation Report Fort Devens Groups 3,5, and 6. Volume 1 of 2: Report Text

    Science.gov (United States)

    1996-01-01

    Acer rubrum), red-osier dogwood (Comus stolonifera), buckthorn (Rhamnus cathartica), and speckled alder (Alnus rugosa ). Other species observed in the...area include gray birch (Betula populifolia), quaking aspen (Populus tremuloides), white pine (Pinus strobus), white oak ( Quercus alba), northern...black cherry (Prunus serotina), white oak ( Quercus alba), European buckthorn (Rhamnus frangula), and white birch (Betula papyrifera). The open understory

  6. Vegetation responses to supplemental winter feeding of elk in western Wyoming

    Science.gov (United States)

    Matthew J. Rinella; Ron Dean; Marty Vavra; Catherine G. Parks

    2012-01-01

    To compensate for losses in overwintering habitat, elk are fed hay in winter at approximately 37 locations throughout the western United States. These winter feeding programs concentrate elk activity, and there is concern that such concentrations could degrade plant communities. Except for one study focused exclusively on aspen (Populus tremuloides...

  7. Planting aspen to rehabilitate riparian areas: a pilot study

    Science.gov (United States)

    Wayne D. Shepperd; Stephen A. Mata

    2005-01-01

    We planted 742 greenhouse-grown containerized aspen seedlings in the riparian area of Hurd Creek on the Arapaho National Forest east of Tabernash, Colorado. Objectives were to (1) determine whether aspen seedlings can be planted in an operational setting and survive in sufficient numbers to successfully establish a mature aspen stand and (2) determine the effectiveness...

  8. Seasonal dynamics of the photosynthetic pigments content in Populus tremula L. leaves at the adaptation on an open-pit coal mine revegetating dump

    Directory of Open Access Journals (Sweden)

    Yu. V. Zagurskaya

    2017-02-01

    Full Text Available Seasonal dynamics of the basic photosynthetic pigments (a and b chlorophylls, carotenoids content in the samples of aspen Populus tremula during natural regeneration on a revegetating pit dump of a worked-out coal pit has been studied. The studies were conducted every ten days during the vegetation period in 2015 (June–September on the territory of «Yuzhniy» dump of «Kedrovskiy» open-pit coal mine (Kemerovo region. The pigment content was identified by the means of spectrophotometric detection. The content of photosynthetic pigments in aspen leaves was calculated on oven-dry weight of the leaves, as moisture aspen leaves can greatly vary, and the determination of accuracy of dry matter content higher than the for specific gravity of the sheet. No changes in visible absorption spectrum of acetone extracts indicating pheophytin formation in chlorophylls have been identified. For all variants the larger amount of b chlorophyll was contained in control samples. The largest differences in a/b chlorophylls and chlorophylls/carotenoids ratio were observed in the end of vegetation period. The ratio between a and b chlorophylls of aspen leaves in both cases by the end of the season was considerably lower. The adaptation of aspen photosynthetic system to the revegetating dump conditions was performed due to decrease in the total pigment content and the percent of b chlorophyll in their composition.

  9. Introduksjon til bruk av prosessimuleringsprogrammet Aspen Plus

    OpenAIRE

    Sjøvik, Torbjørn Eig

    2013-01-01

    Denne masteroppgaven er en introduksjon i bruk av prosessimuleringsprogrammet Aspen Plus, med tanke på framtidig bruk i prosessfagene ved institutt for matematiske realfag og teknologi ved Universitetet for Miljø og Biovitenskap. Målet var å finne ut om programmet er egnet å bruke i undervisning av prosessfag. For å løse problemstillingen ble simuleringer i Aspen Plus satt opp og løst, med økende grad av vanskelighet. Dette resulterte i en brukerveiledning, som kan hjelpe nye brukere i å k...

  10. Aspen: A microsimulation model of the economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.; Quint, T.; Arnold, T.

    1996-10-01

    This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of the model are also presented.

  11. Dicty_cDB: CHR209 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available l02, 5' end. 44 7.6 1 CA929806 |CA929806.1 MTU2CA.P3.A01 Aspen apex cDNA Library ...Populus tremuloides cDNA, mRNA sequence. 44 7.6 1 CA929196 |CA929196.1 MTU2CA.P10.C05 Aspen apex cDNA Librar

  12. Dicty_cDB: CHS394 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 95546.1 Molgula tectiformis cDNA, gonad clone:mtgd025l22, 5' end. 44 7.9 1 CA929806 |CA929806.1 MTU2CA.P3.A01 Aspen apex... cDNA Library Populus tremuloides cDNA, mRNA sequence. 44 7.9 1 CA929196 |CA929196.1 MTU2CA.P10.C05 Aspen apex

  13. Establishment of a Callus Culture System of Populus euphratica, Populus alba cv. Pyramidalis and Populus maximowiczii × Populus plantierensis

    OpenAIRE

    Shen, Hailong; Watanabe, Shin; IDE, Yuji

    1998-01-01

    Populus euphratica(コトカケヤナギ,中国名,胡楊),Populus alba cv. Pyramidalis(中国名,新疆楊),Populus maximowiczii×Populus plantierensis(品種名,FS-51)の3種類のポプラについてカルス培養の基本的手法を確立した。BAP,NAA,2,4-Dを単独あるいは組み合わせて添加したMS培地上でカルス誘導が可能であった。誘導されたカルスは,BAPを0.2mg/l,NAAを1.0mg/l含むMS培地上で継代培養可能であった。また,継代2回目のカルスをBAPを単独あるいはNAAまたはGA3を組み合わせたMS培地上でシュートが再生した。これらのシュートは,1/2MS培地にさしつけることにより発根して植物体が再生した。三種類すべてでカルスの培養と植物体の再生が可能であったが,種によって適当なホルモン条件は異なっていた。...

  14. Aspen Winter Conferences on High Energy

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-02-12

    The 2011 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 12 to February 18, 2011. Ninety-four participants from ten countries, and several universities and national labs attended the workshop titled, "New Data From the Energy Frontier." There were 54 formal talks, and a considerable number of informal discussions held during the week. The week's events included a public lecture ("The Hunt for the Elusive Higgs Boson" given by Ben Kilminster from Ohio State University) and attended by 119 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists. The 2011 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was "Indirect and Direct Detection of Dark Matter." It was held from February 6 to February 12, 2011. The 70 participants came from 7 countries and attended 53 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists from other institutions and countries or due to incipient collaborations. In addition, Blas Cabrera of Stanford University gave a public lecture titled "What Makes Up Dark Matter." There were 183 members of the general public in attendance. Before the lecture, 45 people attended the physics cafe to discuss dark matter. This report provides the attendee lists, programs, and announcement posters for each event.

  15. Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species.

    Science.gov (United States)

    Macaya-Sanz, D; Suter, L; Joseph, J; Barbará, T; Alba, N; González-Martínez, S C; Widmer, A; Lexer, C

    2011-10-01

    Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F(1)'s. Here, we used this approach to understand the genetics of post-mating isolation and barriers to introgression in Populus alba and Populus tremula, two ecologically divergent, hybridizing forest trees. We studied 86 interspecific backcross (BC(1)) progeny and >350 individuals from natural populations of these species for up to 98 nuclear genetic markers, including microsatellites, indels and single nucleotide polymorphisms, and inferred the origin of the cytoplasm of the cross with plastid DNA. Genetic analysis of the BC(1) revealed extensive segregation distortions on six chromosomes, and >90% of these (12 out of 13) favored P. tremula donor alleles in the heterospecific genomic background. Since selection was documented during early diploid stages of the progeny, this surprising result was attributed to epistasis, cyto-nuclear coadaptation, heterozygote advantage at nuclear loci experiencing introgression or a combination of these. Our results indicate that gene flow across 'porous' species barriers affects these poplars and aspens beyond neutral, Mendelian expectations and suggests the mechanisms responsible. Contrary to expectations, the Populus sex determination region is not protected from introgression. Understanding the population dynamics of the Populus sex determination region will require tests based on natural interspecific hybrid zones.

  16. Sustaining aspen in western landscapes: Symposium proceedings; 13-15 June 2000; Grand Junction, CO

    Science.gov (United States)

    Wayne D. Shepperd; Dan Binkley; Dale L. Bartos; Thomas J. Stohlgren; Lane G. Eskew

    2001-01-01

    The current status and trend of aspen is a topic of debate; some studies have claimed dramatic reductions in aspen stands while others have found no major changes. The actual picture of aspen forests across the West is variable, and the presence of conifers and ungulates in aspen may or may not indicate a progressive loss of aspen. These proceedings summarize the state...

  17. Prototype wood chunker used on Populus 'Tristis'

    Science.gov (United States)

    Rodger A. Arola; Roger C. Radcliffe; Sharon A. Winsauer

    1983-01-01

    Populus 'Tristis' trees grown under short-rotation, intensive culture were sampled and chunked in a prototype experimental wood chunking machine. Data presented describe the character of the trees chunked, the energy and power requirements for chunking, and the chunking rates Specific energy requirements for chunking Populus 'Tristis...

  18. Aspen wood characteristics, properties and uses: a review of recent literature.

    Science.gov (United States)

    Fred M. Lamb

    1967-01-01

    Summarizes information on wood properties and uses of quaking aspen from recent literature. Includes current data on the growth and production of aspen in the Lake States. Outlines additional research needs concerning aspen wood properties and uses.

  19. Translating MAPGEN to ASPEN for MER

    Science.gov (United States)

    Rabideau, Gregg R.; Knight, Russell L.; Lenda, Matthew; Maldague, Pierre F.

    2013-01-01

    This software translates MAPGEN (Europa and APGEN) domains to ASPEN, and the resulting domain can be used to perform planning for the Mars Exploration Rover (MER). In other words, this is a conversion of two distinct planning languages (both declarative and procedural) to a third (declarative) planning language in order to solve the problem of faithful translation from mixed-domain representations into the ASPEN Modeling Language. The MAPGEN planning system is an example of a hybrid procedural/declarative system where the advantages of each are leveraged to produce an effective planner/scheduler for MER tactical planning. The adaptation of the planning system (ASPEN) was investigated, and, with some translation, much of the procedural knowledge encoding is amenable to declarative knowledge encoding. The approach was to compose translators from the core languages used for adapting MAGPEN, which consists of Europa and APGEN. Europa is a constraint- based planner/scheduler where domains are encoded using a declarative model. APGEN is also constraint-based, in that it tracks constraints on resources and states and other variables. Domains are encoded in both constraints and code snippets that execute according to a forward sweep through the plan. Europa and APGEN communicate to each other using proxy activities in APGEN that represent constraints and/or tokens in Europa. The composition of a translator from Europa to ASPEN was fairly straightforward, as ASPEN is also a declarative planning system, and the specific uses of Europa for the MER domain matched ASPEN s native encoding fairly closely. On the other hand, translating from APGEN to ASPEN was considerably more involved. On the surface, the types of activities and resources one encodes in APGEN appear to match oneto- one to the activities, state variables, and resources in ASPEN. But, when looking into the definitions of how resources are profiled and activities are expanded, one sees code snippets that access

  20. Aspen Characteristics - El Dorado National Forest [ds363

    Data.gov (United States)

    California Department of Resources — The database represents aspen stand locations and field assessments conducted in the Eldorado National Forest, Eldorado and Amador Counties, California. Data was...

  1. Aspen Characteristics - Plumas National Forest, FRRD [ds375

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Feather River Ranger...

  2. Energy Values of Nine Populus Clones

    Science.gov (United States)

    Terry F. Strong

    1980-01-01

    Compares calorific values for components of nine Populus clones. The components include stem wood, stem bark, and branches. Also compares calorific values for clones of balsam poplar and black cottonwood parentages.

  3. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen

    Energy Technology Data Exchange (ETDEWEB)

    Maja, Mengistu M., E-mail: mengistu.maja@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Kasurinen, Anne; Holopainen, Toini [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Julkunen-Tiitto, Riitta [University of Eastern Finland, Department of Biology, P.O. Box 111, 80101 Joensuu (Finland); Holopainen, Jarmo K. [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland)

    2016-03-15

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient + 2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A + T and UV-B + T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B × temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone

  4. Aspen in action: an Aspen Institute pilot tests a toolkit for transformation in public libraries

    National Research Council Canada - National Science Library

    Witteveen, April

    2016-01-01

    ... to take out to the community," Millsap tells LJ. As libraries engaged with the report, it became clear that many wanted more hands-on guidance about how to take recommendations from Rising to the Challenge and turn them into practical, achievable goals. In response, Aspen developed a new toolkit featuring 12 chapters of "ACTivities" covering topics su...

  5. The effect of aspen wood characteristics and properties on utilization

    Science.gov (United States)

    Kurt H. Mackes; Dennis L. Lynch

    2001-01-01

    This paper reviews characteristics and properties of aspen wood, including anatomical structure and characteristics, moisture and shrinkage properties, weight and specific gravity, mechanical properties, and processing characteristics. Uses of aspen are evaluated: sawn and veneer products, composite panels, pulp, excelsior, post and poles, animal bedding, animal food...

  6. Dynamics of aspen root biomass and sucker production following fire

    Science.gov (United States)

    Roy A. Renkin; Don G. Despain

    2001-01-01

    Changes in preburn aspen root biomass 8 years following prescribed fire were analyzed for five experimental sites distributed across a moisture gradient. Total root biomass decreased across all sites but was proportionately greater in xeric than mesic sites. Response of post-burn aspen suckers to ungulate browsing varied according to site and treatment. Browsing...

  7. Ecology and management of aspen: A Lake States perspective

    Science.gov (United States)

    David T. Cleland; Larry A. Leefers; Donald I. Dickmann

    2001-01-01

    Aspen has been an ecologically important, though relatively minor, component of the Lake States (Michigan, Wisconsin, and Minnesota) forests for millennia. General Land Office records from the 1800s indicate that aspen comprised a small fraction of the region's eastern forests, but was more extensive on the western edge. Then Euro-American settlement in the 1800s...

  8. Aspen restoration in the Blue Mountains of northeast Oregon

    Science.gov (United States)

    Diane M. Shirley; Vicky Erickson

    2001-01-01

    In the Blue Mountains of northeast Oregon, quaking aspen is on the western fringe of its range. It exists as small, scattered, remnant stands of rapidly declining trees. Although little is known about the historic distribution of aspen in Oregon, it is believed that stands were once larger and more widely distributed. Decline of the species is attributed to fire...

  9. F-cell: The Aspen fuel cell model

    Science.gov (United States)

    Regenhardt, P. A.

    1985-03-01

    This report documents the fuel cell model created at the Morgantown Energy Technology Center for systems simulations that use the Advanced System for Process Engineering (ASPEN) simulator. The report includes: (1) an explanation of the thermodynamics involved, (2) an explanation of the efficiencies used to describe and compare a fuel cell, (3) the FORTRAN code and ASPEN system definition file entries required to install the model into the ASPEN system, (4) three sample ASPEN input files demonstrating how the model could be used for phosphoric acid, molten carbonate, and solid oxide fuel cells, (5) a detailed ASPEN input file that simulates a commercial 40-kW phosphoric acid fuel cell system, and (6) the technical and the user entries for the ASPEN manuals. F-CELL is designed to use the results of either a mechanistic model or experimental data to model a fuel cell in a system study. A double set of efficiencies is produced; the first is calculated from the user's input, and the second is based on ASPEN's results. The second set of efficiencies serves as a check on the input data and is not used in any internal calculations. The model also checks for carbon deposition.

  10. Endogenous PttHb1 and PttTrHb, and heterologous Vitreoscilla vhb haemoglobin gene expression in hybrid aspen roots with ectomycorrhizal interaction.

    Science.gov (United States)

    Jokipii, Soile; Häggman, Hely; Brader, Günter; Kallio, Pauli T; Niemi, Karoliina

    2008-01-01

    Present knowledge on plant non-symbiotic class-1 (Hb1) and truncated (TrHb) haemoglobin genes is almost entirely based on herbaceous species while the corresponding tree haemoglobin genes are not well known. The function of these genes has recently been linked with endosymbioses between plants and microbes. In this work, the coding sequences of hybrid aspen (Populus tremulaxtremuloides) PttHb1 and PttTrHb were characterized, indicating that the key residues of haem and ligand binding of both genes were conserved in the deduced amino acid sequences. The expression of PttHb1 and PttTrHb was examined in parallel with that of the heterologous Vitreoscilla haemoglobin gene (vhb) during ectomycorrhiza/ectomycorrhizal (ECM) interaction. Both ECM fungi studied, Leccinum populinum and Xerocomus subtomentosus, enhanced root formation and subsequent growth of roots of all hybrid aspen lines, but only L. populinum was able to form mycorrhizas. Real-time PCR results show that the dual culture with the ECM fungus, with or without emergence of symbiotic structures, increased the expression of both PttHb1 and PttTrHb in the roots of non-transgenic hybrid aspens. PttHb1 and PttTrHb had expression peaks 5 h and 2 d after inoculation, respectively, pointing to different functions for these genes during interaction with root growth-improving fungi. In contrast, ECM fungi were not able to enhance the expression of hybrid aspen endogenous haemoglobin genes in the VHb lines, which may be a consequence of the compensating action of heterologous haemoglobin.

  11. Threshold Responses of Aspen and Spruce Growth to Temperature May Presage a Regime Shift in the Boreal Forest

    Science.gov (United States)

    Lloyd, A. H.; Duffy, P.; Mann, D. H.; Leonawicz, M.; Blumstein, M.; Pendall, E.

    2011-12-01

    Warming in boreal regions may eventually lead to the demise of evergreen coniferous forest and its replacement by either an open parkland of more drought-tolerant deciduous species like aspen, or by treeless steppe vegetation. We examined the possibility of warming-induced regime shifts in the boreal forest by quantifying the response of tree growth to climate on steep, south-facing bluffs in interior Alaska. These sites are the ecotone between forest and subarctic steppe vegetation, and represent the warmest, driest sites occupied by trees in the boreal forests of interior Alaska. We collected tree cores from aspen (Populus tremula) and white spruce (Picea glauca) at south-facing bluffs in interior Alaska (n=9 for white spruce, n=5 for aspen). Crossdated chronologies of detrended, standardized ring-widths were produced for each species at each site, and growth response to climate was quantified using generalized boosting models (spruce) and random forest regression (aspen). These analyses yielded three important insights into the potential for regime shifts in the warmer areas of the boreal forest. First, our results highlighted the surprising similarity in growth response of aspen and spruce. We expected to find that aspen would be more tolerant of warm, dry conditions than white spruce. In contrast, we found that the two species had broadly similar responses to climate, preferring cooler and wetter conditions. This finding suggests that a continued trend towards warmer and drier conditions is more likely to lead rapidly to the replacement of forest vegetation by steppe grassland, rather than the replacement of white spruce by aspen. Second, we identified strongly nonlinear responses to climate in both species; the use of analytical methods capable of detecting and describing nonlinear relationships between growth and climate thus proved to be critical. For both species, steep thresholds in growth response to temperature occurred, particularly in spring. Small

  12. Metabolomics study of Populus type propolis.

    Science.gov (United States)

    Anđelković, Boban; Vujisić, Ljubodrag; Vučković, Ivan; Tešević, Vele; Vajs, Vlatka; Gođevac, Dejan

    2017-02-20

    Herein, we propose rapid and simple spectroscopic methods to determine the chemical composition of propolis derived from various Populus species using a metabolomics approach. In order to correlate variability in Populus type propolis composition with the altitude of its collection, NMR, IR, and UV spectroscopy followed by OPLS was conducted. The botanical origin of propolis was established by comparing propolis spectral data to those of buds of various Populus species. An O2PLS method was utilized to integrate two blocks of data. According to OPLS and O2PLS, the major compounds in propolis samples, collected from temperate continental climate above 500m, were phenolic glycerides originating from P. tremula buds. Flavonoids were predominant in propolis samples collected below 400m, originating from P. nigra and P. x euramericana buds. Samples collected at 400-500m were of mixed origin, with variable amounts of all detected metabolites. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Aspen Grupp võitis RKASi / Lemmi Kann

    Index Scriptorium Estoniae

    Kann, Lemmi

    2008-01-01

    Ehitusfirma Aspen Grupp OÜ võitis Tallinna ringkonnakohtus Riigi Kinnisvara AS-i, kes diskvalifitseeris ehitusfirma riigihankelt seaduses olnud maksevõlgnevuse keelu tõttu. Vt. samas: Lahendust ootavad veel kaks kohtuasja

  14. Wood Pyrolysis Using Aspen Plus Simulation and Industrially Applicable Model

    National Research Council Canada - National Science Library

    Pavel Lestinsky; Aloy Palit

    2016-01-01

    .... Furthermore, the model of pyrolysis was created using Aspen Plus software. Aspects of pyrolysis are discussed with a description of how various temperatures affect the overall reaction rate and the yield of volatile components...

  15. Epigenomics of Development in Populus

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Steve; Freitag, Michael; Mockler, Todd

    2013-01-10

    We conducted research to determine the role of epigenetic modifications during tree development using poplar (Populus trichocarpa), a model woody feedstock species. Using methylated DNA immunoprecipitation (MeDIP) or chromatin immunoprecipitation (ChIP), followed by high-throughput sequencing, we are analyzed DNA and histone methylation patterns in the P. trichocarpa genome in relation to four biological processes: bud dormancy and release, mature organ maintenance, in vitro organogenesis, and methylation suppression. Our project is now completed. We have 1) produced 22 transgenic events for a gene involved in DNA methylation suppression and studied its phenotypic consequences; 2) completed sequencing of methylated DNA from eleven target tissues in wildtype P. trichocarpa; 3) updated our customized poplar genome browser using the open-source software tools (2.13) and (V2.2) of the P. trichocarpa genome; 4) produced summary data for genome methylation in P. trichocarpa, including distribution of methylation across chromosomes and in and around genes; 5) employed bioinformatic and statistical methods to analyze differences in methylation patterns among tissue types; and 6) used bisulfite sequencing of selected target genes to confirm bioinformatics and sequencing results, and gain a higher-resolution view of methylation at selected genes 7) compared methylation patterns to expression using available microarray data. Our main findings of biological significance are the identification of extensive regions of the genome that display developmental variation in DNA methylation; highly distinctive gene-associated methylation profiles in reproductive tissues, particularly male catkins; a strong whole genome/all tissue inverse association of methylation at gene bodies and promoters with gene expression; a lack of evidence that tissue specificity of gene expression is associated with gene methylation; and evidence that genome methylation is a significant impediment to tissue

  16. The genome of black cottonwood, Populus trichocarpa (Torr.&Gray)

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, G.A.; DiFazio, S.; Jansson, S.; Bohlmann, J.; Grigoriev,I.; Hellsten, U.; Putnam, N.; Ralph, S.; Rombauts, S.; Salamov, A.; Schein, J.; Sterck, L.; Aerts, A.; Bhalerao, R.R.; Bhalerao, R.P.; Blaudez, D.; Boerjan, W.; Brun, A.; Brunner, A.; Busov, V.; Campbell, M.; Carlson, J.; Chalot, M.; Chapman, J.; Chen, G.-L.; Cooper, D.; Coutinho,P.M.; Couturier, J.; Covert, S.; Cronk, Q.; Cunningham, R.; Davis, J.; Degroeve, S.; Dejardin, A.; dePamphillis, C.; Detter, J.; Dirks, B.; Dubchak, I.; Duplessis, S.; Ehiting, J.; Ellis, B.; Gendler, K.; Goodstein, D.; Gribskov, M.; Grimwood, J.; Groover, A.; Gunter, L.; Hamberger, B.; Heinze, B.; Helariutta, Y.; Henrissat, B.; Holligan, D.; Holt, R.; Huang, W.; Islam-Faridi, N.; Jones, S.; Jones-Rhoades, M.; Jorgensen, R.; Joshi, C.; Kangasjarvi, J.; Karlsson, J.; Kelleher, C.; Kirkpatrick, R.; Kirst, M.; Kohler, A.; Kalluri, U.; Larimer, F.; Leebens-Mack, J.; Leple, J.-C.; Locascio, P.; Lou, Y.; Lucas, S.; Martin,F.; Montanini, B.; Napoli, C.; Nelson, D.R.; Nelson, D.; Nieminen, K.; Nilsson, O.; Peter, G.; Philippe, R.; Pilate, G.; Poliakov, A.; Razumovskaya, J.; Richardson, P.; Rinaldi, C.; Ritland, K.; Rouze, P.; Ryaboy, D.; Schmutz, J.; Schrader, J.; Segerman, B.; Shin, H.; Siddiqui,A.; Sterky, F.; Terry, A.; Tsai, C.; Uberbacher, E.; Unneberg, P.; Vahala, J.; Wall, K.; Wessler, S.; Yang, G.; Yin, T.; Douglas, C.; Marra,M.; Sandberg, G.; Van der Peer, Y.; Rokhsar, D.

    2006-09-01

    We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. Over 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event, with approximately 8,000 pairs of duplicated genes from that event surviving in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication and gross chromosomal rearrangement appear to proceed substantially slower in Populus relative to Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average between 1.4-1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with disease resistance, meristem development, metabolite transport and lignocellulosic wall biosynthesis.

  17. Functional analyses of Populus euphratica brassinosteroid biosyn ...

    Indian Academy of Sciences (India)

    2016-09-28

    Sep 28, 2016 ... thesis enzyme genes DWF4 (PeDWF4) and CPD (PeCPD) in the regulation of growth and development of Arabidopsis thaliana. DWF4 and CPD are key brassinosteroids (BRs) biosynthesis enzyme genes. To explore the function of Populus euphratica DWF4 (PeDWF4) and CPD (PeCPD), Arabidopsis ...

  18. Subcellular localization of cadmium in hyperaccumulator Populus ...

    African Journals Online (AJOL)

    ... of damage to organs of grey poplar was as follows: root > stem> leaves. It was suggested that the Populus × canescens as a renewable resource has the potential to decontaminate cadmium stress development, accumulation and distribution. Key words: Cadmium, phytoremediation, hyperaccumulator, grey poplar, organ.

  19. Barcoding poplars (Populus L.) from western China.

    Science.gov (United States)

    Feng, Jianju; Jiang, Dechun; Shang, Huiying; Dong, Miao; Wang, Gaini; He, Xinyu; Zhao, Changming; Mao, Kangshan

    2013-01-01

    Populus is an ecologically and economically important genus of trees, but distinguishing between wild species is relatively difficult due to extensive interspecific hybridization and introgression, and the high level of intraspecific morphological variation. The DNA barcoding approach is a potential solution to this problem. Here, we tested the discrimination power of five chloroplast barcodes and one nuclear barcode (ITS) among 95 trees that represent 21 Populus species from western China. Among all single barcode candidates, the discrimination power is highest for the nuclear ITS, progressively lower for chloroplast barcodes matK (M), trnG-psbK (G) and psbK-psbI (P), and trnH-psbA (H) and rbcL (R); the discrimination efficiency of the nuclear ITS (I) is also higher than any two-, three-, or even the five-locus combination of chloroplast barcodes. Among the five combinations of a single chloroplast barcode plus the nuclear ITS, H+I and P+I differentiated the highest and lowest portion of species, respectively. The highest discrimination rate for the barcodes or barcode combinations examined here is 55.0% (H+I), and usually discrimination failures occurred among species from sympatric or parapatric areas. In this case study, we showed that when discriminating Populus species from western China, the nuclear ITS region represents a more promising barcode than any maternally inherited chloroplast region or combination of chloroplast regions. Meanwhile, combining the ITS region with chloroplast regions may improve the barcoding success rate and assist in detecting recent interspecific hybridizations. Failure to discriminate among several groups of Populus species from sympatric or parapatric areas may have been the result of incomplete lineage sorting, frequent interspecific hybridizations and introgressions. We agree with a previous proposal for constructing a tiered barcoding system in plants, especially for taxonomic groups that have complex evolutionary histories

  20. Barcoding poplars (Populus L. from western China.

    Directory of Open Access Journals (Sweden)

    Jianju Feng

    Full Text Available BACKGROUND: Populus is an ecologically and economically important genus of trees, but distinguishing between wild species is relatively difficult due to extensive interspecific hybridization and introgression, and the high level of intraspecific morphological variation. The DNA barcoding approach is a potential solution to this problem. METHODOLOGY/PRINCIPAL FINDINGS: Here, we tested the discrimination power of five chloroplast barcodes and one nuclear barcode (ITS among 95 trees that represent 21 Populus species from western China. Among all single barcode candidates, the discrimination power is highest for the nuclear ITS, progressively lower for chloroplast barcodes matK (M, trnG-psbK (G and psbK-psbI (P, and trnH-psbA (H and rbcL (R; the discrimination efficiency of the nuclear ITS (I is also higher than any two-, three-, or even the five-locus combination of chloroplast barcodes. Among the five combinations of a single chloroplast barcode plus the nuclear ITS, H+I and P+I differentiated the highest and lowest portion of species, respectively. The highest discrimination rate for the barcodes or barcode combinations examined here is 55.0% (H+I, and usually discrimination failures occurred among species from sympatric or parapatric areas. CONCLUSIONS/SIGNIFICANCE: In this case study, we showed that when discriminating Populus species from western China, the nuclear ITS region represents a more promising barcode than any maternally inherited chloroplast region or combination of chloroplast regions. Meanwhile, combining the ITS region with chloroplast regions may improve the barcoding success rate and assist in detecting recent interspecific hybridizations. Failure to discriminate among several groups of Populus species from sympatric or parapatric areas may have been the result of incomplete lineage sorting, frequent interspecific hybridizations and introgressions. We agree with a previous proposal for constructing a tiered barcoding system in

  1. Contrasting patterns of cytokinins between years in senescing aspen leaves

    Czech Academy of Sciences Publication Activity Database

    Edlund, E.; Novák, Ondřej; Karady, M.; Ljung, K.; Jansson, S.

    2017-01-01

    Roč. 40, č. 5 (2017), s. 622-634 ISSN 0140-7791 R&D Projects: GA ČR GA14-34792S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : leaf senescence * arabidopsis-thaliana * autumn senescence * gene-expression * populus-trichocarpa * mass-spectrometry * tobacco plant s * translocation * biosynthesis * identification * autumn senescence * gene expression * metabolism * Populus tremula * profiling Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 6.173, year: 2016

  2. Effects of hybridization and evolutionary constraints on secondary metabolites: the genetic architecture of phenylpropanoids in European populus species.

    Directory of Open Access Journals (Sweden)

    Celine Caseys

    Full Text Available The mechanisms responsible for the origin, maintenance and evolution of plant secondary metabolite diversity remain largely unknown. Decades of phenotypic studies suggest hybridization as a key player in generating chemical diversity in plants. Knowledge of the genetic architecture and selective constraints of phytochemical traits is key to understanding the effects of hybridization on plant chemical diversity and ecological interactions. Using the European Populus species P. alba (White poplar and P. tremula (European aspen and their hybrids as a model, we examined levels of inter- and intraspecific variation, heritabilities, phenotypic correlations, and the genetic architecture of 38 compounds of the phenylpropanoid pathway measured by liquid chromatography and mass spectrometry (UHPLC-MS. We detected 41 quantitative trait loci (QTL for chlorogenic acids, salicinoids and flavonoids by genetic mapping in natural hybrid crosses. We show that these three branches of the phenylpropanoid pathway exhibit different geographic patterns of variation, heritabilities, and genetic architectures, and that they are affected differently by hybridization and evolutionary constraints. Flavonoid abundances present high species specificity, clear geographic structure, and strong genetic determination, contrary to salicinoids and chlorogenic acids. Salicinoids, which represent important defence compounds in Salicaceae, exhibited pronounced genetic correlations on the QTL map. Our results suggest that interspecific phytochemical differentiation is concentrated in downstream sections of the phenylpropanoid pathway. In particular, our data point to glycosyltransferase enzymes as likely targets of rapid evolution and interspecific differentiation in the 'model forest tree' Populus.

  3. Effects of Hybridization and Evolutionary Constraints on Secondary Metabolites: The Genetic Architecture of Phenylpropanoids in European Populus Species

    Science.gov (United States)

    Caseys, Celine; Stritt, Christoph; Glauser, Gaetan; Blanchard, Thierry; Lexer, Christian

    2015-01-01

    The mechanisms responsible for the origin, maintenance and evolution of plant secondary metabolite diversity remain largely unknown. Decades of phenotypic studies suggest hybridization as a key player in generating chemical diversity in plants. Knowledge of the genetic architecture and selective constraints of phytochemical traits is key to understanding the effects of hybridization on plant chemical diversity and ecological interactions. Using the European Populus species P. alba (White poplar) and P. tremula (European aspen) and their hybrids as a model, we examined levels of inter- and intraspecific variation, heritabilities, phenotypic correlations, and the genetic architecture of 38 compounds of the phenylpropanoid pathway measured by liquid chromatography and mass spectrometry (UHPLC-MS). We detected 41 quantitative trait loci (QTL) for chlorogenic acids, salicinoids and flavonoids by genetic mapping in natural hybrid crosses. We show that these three branches of the phenylpropanoid pathway exhibit different geographic patterns of variation, heritabilities, and genetic architectures, and that they are affected differently by hybridization and evolutionary constraints. Flavonoid abundances present high species specificity, clear geographic structure, and strong genetic determination, contrary to salicinoids and chlorogenic acids. Salicinoids, which represent important defence compounds in Salicaceae, exhibited pronounced genetic correlations on the QTL map. Our results suggest that interspecific phytochemical differentiation is concentrated in downstream sections of the phenylpropanoid pathway. In particular, our data point to glycosyltransferase enzymes as likely targets of rapid evolution and interspecific differentiation in the ‘model forest tree’ Populus. PMID:26010156

  4. Effects of hybridization and evolutionary constraints on secondary metabolites: the genetic architecture of phenylpropanoids in European populus species.

    Science.gov (United States)

    Caseys, Celine; Stritt, Christoph; Glauser, Gaetan; Blanchard, Thierry; Lexer, Christian

    2015-01-01

    The mechanisms responsible for the origin, maintenance and evolution of plant secondary metabolite diversity remain largely unknown. Decades of phenotypic studies suggest hybridization as a key player in generating chemical diversity in plants. Knowledge of the genetic architecture and selective constraints of phytochemical traits is key to understanding the effects of hybridization on plant chemical diversity and ecological interactions. Using the European Populus species P. alba (White poplar) and P. tremula (European aspen) and their hybrids as a model, we examined levels of inter- and intraspecific variation, heritabilities, phenotypic correlations, and the genetic architecture of 38 compounds of the phenylpropanoid pathway measured by liquid chromatography and mass spectrometry (UHPLC-MS). We detected 41 quantitative trait loci (QTL) for chlorogenic acids, salicinoids and flavonoids by genetic mapping in natural hybrid crosses. We show that these three branches of the phenylpropanoid pathway exhibit different geographic patterns of variation, heritabilities, and genetic architectures, and that they are affected differently by hybridization and evolutionary constraints. Flavonoid abundances present high species specificity, clear geographic structure, and strong genetic determination, contrary to salicinoids and chlorogenic acids. Salicinoids, which represent important defence compounds in Salicaceae, exhibited pronounced genetic correlations on the QTL map. Our results suggest that interspecific phytochemical differentiation is concentrated in downstream sections of the phenylpropanoid pathway. In particular, our data point to glycosyltransferase enzymes as likely targets of rapid evolution and interspecific differentiation in the 'model forest tree' Populus.

  5. The SHORT-ROOT-like gene PtSHR2B is involved in Populus phellogen activity.

    Science.gov (United States)

    Miguel, Andreia; Milhinhos, Ana; Novák, Ondřej; Jones, Brian; Miguel, Célia M

    2016-03-01

    SHORT-ROOT (SHR) is a GRAS transcription factor first characterized for its role in the specification of the stem cell niche and radial patterning in Arabidopsis thaliana (At) roots. Three SHR-like genes have been identified in Populus trichocarpa (Pt). PtSHR1 shares high similarity with AtSHR over the entire length of the coding sequence. The two other Populus SHR-like genes, PtSHR2A and PtSHR2B, are shorter in their 5' ends when compared with AtSHR. Unlike PtSHR1, that is expressed throughout the cambial zone of greenhouse-grown Populus trees, PtSHR2Bprom:uidA expression was detected in the phellogen. Additionally, PtSHR1 and PtSHR2B expression patterns markedly differ in the shoot apex and roots of in vitro plants. Transgenic hybrid aspen expressing PtSHR2B under the 35S constitutive promoter showed overall reduced tree growth while the proportion of bark increased relative to the wood. Reverse transcription-quantitative PCR (RT-qPCR) revealed increased transcript levels of cytokinin metabolism and response-related genes in the transgenic plants consistent with an increase of total cytokinin levels. This was confirmed by cytokinin quantification by LC-MS/MS. Our results indicate that PtSHR2B appears to function in the phellogen and therefore in the regulation of phellem and periderm formation, possibly acting through modulation of cytokinin homeostasis. Furthermore, this work points to a functional diversification of SHR after the divergence of the Populus and Arabidopsis lineages. This finding may contribute to selection and breeding strategies of cork oak in which, unlike Populus, the phellogen is active throughout the entire tree lifespan, being at the basis of a highly profitable cork industry. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  6. Aspen Global Change Institute Summer Science Sessions

    Energy Technology Data Exchange (ETDEWEB)

    Katzenberger, John; Kaye, Jack A

    2006-10-01

    The Aspen Global Change Institute (AGCI) successfully organized and convened six interdisciplinary meetings over the course of award NNG04GA21G. The topics of the meetings were consistent with a range of issues, goals and objectives as described within the NASA Earth Science Enterprise Strategic Plan and more broadly by the US Global Change Research Program/Our Changing Planet, the more recent Climate Change Program Strategic Plan and the NSF Pathways report. The meetings were chaired by two or more leaders from within the disciplinary focus of each session. 222 scholars for a total of 1097 participants-days were convened under the auspices of this award. The overall goal of each AGCI session is to further the understanding of Earth system science and global environmental change through interdisciplinary dialog. The format and structure of the meetings allows for presentation by each participant, in-depth discussion by the whole group, and smaller working group and synthesis activities. The size of the group is important in terms of the group dynamics and interaction, and the ability for each participant's work to be adequately presented and discussed within the duration of the meeting, while still allowing time for synthesis

  7. Growth and dieback of aspen forests in northwestern Alberta, Canada, in relation to climate and insects

    National Research Council Canada - National Science Library

    Hogg E.H; Brandt J.P; Kochtubajda B

    2002-01-01

    ..., with >1000 Tg of carbon stored in the aboveground biomass of this species. Since the early 1990s, aspen dieback has been noted over parts of the southern boreal forest and aspen parkland in western Canada...

  8. The extent and characteristics of low productivity aspen areas in Minnesota.

    Science.gov (United States)

    Gerhard K. Raile; Jerold T. Hahn

    1982-01-01

    Plot data from 1977 Minnesota forest inventory were used to evaluate the productivity of Minnesota's aspen forest. Computer simulation was used to develop equations for evaluating the current and potential productivity of aspen forest stands. The analysis showed that 49% of the state's aspen forest type was producing less than half of potential volume yields...

  9. Simulation of quaking aspen potential fire behavior in Northern Utah, USA

    Science.gov (United States)

    R. Justin DeRose; A. Joshua Leffler

    2014-01-01

    Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and...

  10. Aspen overstory recruitment in northern Yellowstone National Park during the last 200 years

    Science.gov (United States)

    Eric J. Larsen; William J. Ripple

    2001-01-01

    Using a monograph provided by Warren (1926) and two sets of aspen increment cores collected in 1997 and 1998, we analyzed aspen overstory recruitment in Yellowstone National Park (YNP) over the past 200 years. We found that successful aspen overstory recruitment occurred on the northern range of YNP from the middle to late 1700s until the 1920s, after which it...

  11. Grindstone Flat and Big Flat enclosures - 41-year record of changes in clearcut aspen communities

    Science.gov (United States)

    Walter F. Mueggler; Dale L. Bartos

    1977-01-01

    The role of deer and cattle in the failure of aspen stands to regenerate on Beaver Mountain in southern Utah was investigated by a series of exclosures constructed in 1934. Three-fourths of each exclosure was clearcut of aspen in 1934. Aspen reproduction, shrubs, and herbaceous understory were measured in 1937, 1942, 1949, and 1975. Implications of wildlife and...

  12. Biodiversity: Aspen stands have the lead, but will nonnative species take over?

    Science.gov (United States)

    Geneva W. Chong; Sara E. Simonson; Thomas J. Stohlgren; Mohammed A. Kalkhan

    2001-01-01

    We investigated vascular plant and butterfly diversity in Rocky Mountain National Park. We identified 188 vascular plant species unique to the aspen vegetation type. The slope of the mean species-area curve for the aspen vegetation type was the steepest of the 10 types sampled, thus, an increase in aspen area could have much greater positive impacts on plant species...

  13. Wood Pyrolysis Using Aspen Plus Simulation and Industrially Applicable Model

    Directory of Open Access Journals (Sweden)

    Lestinsky Pavel

    2016-03-01

    Full Text Available Over the past decades, a great deal of experimental work has been carried out on the development of pyrolysis processes for wood and waste materials. Pyrolysis is an important phenomenon in thermal treatment of wood, therefore, the successful modelling of pyrolysis to predict the rate of volatile evolution is also of great importance. Pyrolysis experiments of waste spruce sawdust were carried out. During the experiment, gaseous products were analysed to determine a change in the gas composition with increasing temperature. Furthermore, the model of pyrolysis was created using Aspen Plus software. Aspects of pyrolysis are discussed with a description of how various temperatures affect the overall reaction rate and the yield of volatile components. The pyrolysis Aspen plus model was compared with the experimental data. It was discovered that the Aspen Plus model, being used by several authors, is not good enough for pyrolysis process description, but it can be used for gasification modelling.

  14. Growth of Suspension Cultured Cell of Populus euphratica, Populus alba cv. Pyramidalis and Populus maximowiczii×Populus plantierensis in NaCl Containing Medium

    OpenAIRE

    Shen, Hailong; Watanabe, Shin; IDE, Yuji

    1999-01-01

    Populus euphratica, Populus alba cv. Pyramidalis, Populus maximowiczii×Populus plantierensisの3種のポプラの培養細胞について,培地へのNaClの添加量を徐々に増加させた場合の耐性を評価した。NaClを添加した最初の培養では,P. euphratica, P. maximowiczii×P. plantierensisの細胞は,200mMのNaCl添加では成長が著しく抑制された。また,P. alba cv. Pyramidalisの細胞では150mMのNaCl添加で成長が抑制された。しかし,培養を繰り返すうちに細胞はNaClに対する適応性を発達させ,6回目の継代培養終了時には,P. euphraticaの細胞は200mM, P. alba cv. Pyramidalisの細胞は150mMのNaCl添加培地でも良好な成長が可能になった。しかし,P. maximowiczii×P. plantierensisの細胞は,100mMまででしか良好な成長を示さなくなった。高NaCl条件下において種ごと...

  15. Aspen phenylpropanoid genes' expression levels correlate with genets' tannin richness and vary both in responses to soil nitrogen and associations with phenolic profiles.

    Science.gov (United States)

    Decker, Vicki H G; Bandau, Franziska; Gundale, Michael J; Cole, Christopher T; Albrectsen, Benedicte R

    2017-02-01

    Condensed tannin (CT) contents of European aspen (Populus tremula L.) vary among genotypes, and increases in nitrogen (N) availability generally reduce plants' tannin production in favor of growth, through poorly understood mechanisms. We hypothesized that intrinsic tannin production rates may co-vary with gene expression responses to soil N and resource allocation within the phenylpropanoid pathway (PPP). Thus, we examined correlations between soil N levels and both expression patterns of eight PPP genes (measured by quantitative-reverse transcription PCR) and foliar phenolic compounds (measured by liquid chromatography-mass spectrometry) in young aspen genets with intrinsically extreme CT levels. Monitored phenolics included salicinoids, lignins, flavones, flavonols, CT precursors and CTs. The PPP genes were consistently expressed more strongly in high-CT trees. Low N supplements reduced expression of genes throughout the PPP in all genets, while high N doses restored expression of genes at the beginning and end of the pathway. These PPP changes were not reflected in pools of tannin precursors, but varying correlations between gene expression and foliar phenolic pools were detected in young and mature leaves, suggesting that processes linking gene expression and the resulting phenolics vary spatially and temporally. Precursor fluxes suggested that CT-related metabolic rate or sink controls are linked to intrinsic carbon allocation strategies associated with N responses. Overall, we found more negative correlations (indicative of allocation trade-offs) between PPP gene expression and phenolic products following N additions in low-CT plants than in high-CT plants. The tannin-related expression dynamics suggest that, in addition to defense, relative tannin levels may also be indicative of intraspecific variations in the way aspen genets respond to soil fertility. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e

  16. A study of polymerization of aspen (Populus) wood lipophilic extractives by SEC and Py-GC/MS

    CSIR Research Space (South Africa)

    Sithole, Bruce

    2013-03-01

    Full Text Available of the analyses are expressed as polystyrene equivalent; therefore they are not absolute values. P YROLYSIS - GAS CHROMATOGRAPHY WITH M ASS SPECTROMETRY DETECTION Py/GC/MS is an instrumental method that enables a reproducible characterization... that are not amenable to analysis by GC and GC/MS are ideal candidates for Py-GC/MS analysis. The analytical conditions were as follows: P YROLYSER : PY-2020 (Frontier Laboratories, Japan) attached to a capillary column) Oven temperature: 300 o...

  17. Dicty_cDB: CFH352 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 76 7e-24 4 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...40 2e-09 3 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  18. Dicty_cDB: CFF820 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 52 2e-16 4 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...40 1e-08 3 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  19. Dicty_cDB: SFD257 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 52 2e-16 4 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...40 1e-08 3 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  20. Dicty_cDB: CHD461 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 46 2e-13 5 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...40 3e-09 3 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  1. Dicty_cDB: CFH296 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 34 6e-11 19 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...1e-09 21 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  2. Dicty_cDB: SFJ248 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 76 6e-24 4 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...52 4e-14 4 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  3. Dicty_cDB: VFI285 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 34 0.46 2 BU835483 |BU835483.1 T074E04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...46 0.64 1 BU828329 |BU828329.1 K021P03P Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  4. Dicty_cDB: CFE779 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 38 0.002 4 BU835350 |BU835350.1 T072G09 Populus apical shoot cDNA library Populus tremula x Populus tremuloides...38 0.002 2 BU824990 |BU824990.1 UK102C04 Populus apical shoot cDNA library Populus tremula x Populus tremuloides

  5. Survival and growth of 31 Populus clones in South Carolina

    Science.gov (United States)

    David R. Coyle; Mark D. Coleman; Jaclin A. Durant; Lee A. Newman

    2006-01-01

    Populus species and hybrids have many practical applications, but clonal performance is relatively undocumented in the southeastern United States outside of the Mississippi River alluvial floodplain. In spring 2001, 31 Populus clones were planted on two sites in South Carolina, USA. The sandy, upland site received irrigation and...

  6. Growth and biomass of Populus irrigated with landfill leachate

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; David R. Coyle; Richard B. Hall

    2007-01-01

    Resource managers are challenged with waste disposal and leachate produced from its degradation. Poplar (Populus spp.) trees offer an opportunity for ecological leachate disposal as an irrigation source for managed tree systems. Our objective was to irrigate Populus trees with municipal solid waste landfill leachate or fertilized well water (control...

  7. Defining Excellence: Lessons from the 2013 Aspen Prize Finalists

    Science.gov (United States)

    Aspen Institute, 2013

    2013-01-01

    In many respects, one couldn't find a group of 10 schools more diverse than the finalists for the 2013 Aspen Prize for Community College Excellence. One community college serves 1,500 students, another 56,000. There are institutions devoted primarily--even solely--to technical degrees, and ones devoted mainly to preparing students for further…

  8. The 2013 Aspen Prize for Community College Excellence

    Science.gov (United States)

    Perlstein, Linda

    2013-01-01

    For millions of Americans, community colleges provide an essential pathway to well-paying jobs and continuing higher education. The Aspen Prize for Community College Excellence honors those institutions that strive for and achieve exceptional levels of success for all students, while they are in college and after they graduate. Community colleges…

  9. Modeling of carbonic acid pretreatment process using ASPEN-Plus.

    Science.gov (United States)

    Jayawardhana, Kemantha; Van Walsum, G Peter

    2004-01-01

    ASPEN-Plus process modeling software is used to model carbonic acid pretreatment of biomass. ASPEN-Plus was used because of the thorough treatment of thermodynamic interactions and its status as a widely accepted process simulator. Because most of the physical property data for many of the key components used in the simulation of pretreatment processes are not available in the standard ASPEN-Plus property databases, values from an in-house database (INHSPCD) developed by the National Renewable Energy Laboratory were used. The standard non-random-two-liquid (NRTL) or renon route was used as the main property method because of the need to distill ethanol and to handle dissolved gases. The pretreatment reactor was modeled as a "black box" stoichiometric reactor owing to the unavailability of reaction kinetics. The ASPEN-Plus model was used to calculate the process equipment costs, power requirements, and heating and cooling loads. Equipment costs were derived from published modeling studies. Wall thickness calculations were used to predict construction costs for the high-pressure pretreatment reactor. Published laboratory data were used to determine a suitable severity range for the operation of the carbonic acid reactor. The results indicate that combined capital and operating costs of the carbonic acid system are slightly higher than an H2SO4-based system and highly sensitive to reactor pressure and solids concentration.

  10. A comparison of the pharmacokinetics of Aspen Ceftriaxone and ...

    African Journals Online (AJOL)

    glucose, protein, bacterial antigens, culture and antibiotic susceptibility ... precipitation of proteins to release ceftriaxone into the supernatant. .... drug: 9 deaths were due to concurrent illness, 4 to cerebral lesions complicating meningitis and in 3, cause of death was unknown. Table 2. APACHE II scores. Aspen Ceftriaxone*.

  11. Preliminary study on flakeboard panels made from aspen slash wood

    Science.gov (United States)

    Yan Yu; Alan Rudie; Zhiyong Cai

    2010-01-01

    The disposal of forest-thinning residue is one of the major problems for sustainable forest management. The purpose of this study was to investigate the technical possibility of utilizing aspen logging slash wood with a diameter ranging from 50 to 76 mm for flakeboard production. Influences of weight ratio between slash wood and commercial flakes on the selected...

  12. Aspen fencing in northern Arizona: A 15-year perspective

    Science.gov (United States)

    James M. Rolf

    2001-01-01

    Aspen clearcuts in the 1960s and 1970s on the Peaks Ranger District of the Coconino National Forest in northern Arizona failed to regenerate successfully because of browsing primarily by elk. Since 1985, over 400 acres have been successfully regenerated using fencing of various designs to exclude elk. The expense and visual impact of establishing and maintaining over...

  13. Identification and characterization of the Populus AREB/ABF subfamily.

    Science.gov (United States)

    Ji, Lexiang; Wang, Jia; Ye, Meixia; Li, Ying; Guo, Bin; Chen, Zhong; Li, Hao; An, Xinmin

    2013-02-01

    Abscisic acid (ABA) is a major plant hormone that plays an important role in responses to abiotic stresses. The ABA-responsive element binding protein/ABRE-binding factor (AREB/ABF) gene subfamily contains crucial transcription factors in the ABA-mediated signaling pathway. In this study, a total of 14 putative AREB/ABF members were identified in the Populus trichocarpa Torr. & Gray. genome using five AREB/ABF amino acid sequences from Arabidopsis thaliana L. as probes. The 14 putative Populus subfamily members showed high protein similarities, especially in the basic leucine zipper (bZIP) domain region. A neighbor-joining analysis combined with gene structure data revealed homology among the 14 genes. The expression patterns of the Populus AREB/ABF subfamily suggested that the most abundant transcripts of 11 genes occurred in leaf tissues, while two genes were most transcribed in root tissues. Significantly, eight Populus AREB/ABF gene members were upregulated after treatment with 100 μM exogenous ABA, while the other six members were downregulated. We identified the expression profiles of the subfamily members in Populus tissues and elucidated different response patterns of Populus AREB/ABF members to ABA stress. This study provided insight into the roles of Populus AREB/ABF homologues in plant response to abiotic stresses. © 2012 Institute of Botany, Chinese Academy of Sciences.

  14. Antimicrobial flavonoids from the twigs of Populus nigra x Populus deltoides.

    Science.gov (United States)

    Zhong, Lingyun; Zhou, Ligang; Zhou, Yaming; Chen, Yuanquan; Sui, Peng; Wang, Jingguo; Wang, Mingan

    2012-01-01

    A bioassay-guided fractionation of the ethyl acetate extract from the twigs of the hybrid poplar 'Neva', Populus nigra L. × Populus deltoides Marsh, led to the isolation of three flavonoids, which were identified by means of spectrometric and physicochemical analysis as 5-hydroxy-7-methoxy-flavone (1), 5,7-dihydoxy-flavone (2) and 5,7-dihydroxy-flavonol (3). These compounds were further screened for their antimicrobial activity against plant pathogens, including three bacteria (Pseudomonas lachrymans, Ralstonia solanacearum and Xanthomonas vesicatoria) and one fungus (Magnaporthe oryzae). Compounds 2 and 3 showed significant antibacterial activity, with minimum inhibitory concentrations (MICs) ranging from 15 to 25 µg mL(-1), and median inhibitory concentrations (IC(50) values) from 4 to 18 µg mL(-1). The results obtained provide promising baseline information for the potential use of the extract and flavonoids from this plant as antimicrobial agents to help control plant diseases.

  15. Sap flux in pure aspen and mixed aspen-birch forests exposed to elevated concentrations of carbon dioxide and ozone.

    Science.gov (United States)

    Uddling, Johan; Teclaw, Ronald M; Kubiske, Mark E; Pregitzer, Kurt S; Ellsworth, David S

    2008-08-01

    Elevated concentrations of atmospheric carbon dioxide ([CO2]) and tropospheric ozone ([O3]) have the potential to affect tree physiology and structure and hence forest water use, which has implications for climate feedbacks. We investigated how a 40% increase above ambient values in [CO2] and [O3], alone and in combination, affect tree water use of pure aspen and mixed aspen-birch forests in the free air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). Measurements of sap flux and canopy leaf area index (L) were made during two growing seasons, when steady-state L had been reached after more than 6 years of exposure to elevated [CO2] and [O3]. Maximum stand-level sap flux was not significantly affected by elevated [O3], but was increased by 18% by elevated [CO2] averaged across years, communities and O(3) regimes. Treatment effects were similar in pure aspen and mixed aspen-birch communities. Increased tree water use in response to elevated [CO2] was related to positive CO2 treatment effects on tree size and L (+40%). Tree water use was not reduced by elevated [O3] despite strong negative O3 treatment effects on tree size and L (-22%). Elevated [O3] predisposed pure aspen stands to drought-induced sap flux reductions, whereas increased tree water use in response to elevated [CO2] did not result in lower soil water content in the upper soil or decreasing sap flux relative to control values during dry periods. Maintenance of soil water content in the upper soil in the elevated [CO2] treatment was at least partly a function of enhanced soil water-holding capacity, probably a result of increased organic matter content from increased litter inputs. Our findings that larger trees growing in elevated [CO2] used more water and that tree size, but not maximal water use, was negatively affected by elevated [O3] suggest that the long-term cumulative effects on stand structure may be more important than the expected primary stomatal closure responses to

  16. Quaking aspen reproduce from seed after wildfire in the mountains of southeastern Arizona

    Science.gov (United States)

    Ronald D. Quinn; Lin Wu

    2001-01-01

    Quaking aspen regenerated from seed after a stand replacement wildfire in the Chiricahua Mountains of southeastern Arizona. The wildfire had created gaps in the canopy so that aspen were able to establish from seed. Seedlings were found at a mean density of 0.17 m-2, 30 m or more from the nearest potential seed trees. Six clumps of aspen seedlings contained 18-186...

  17. Genotypic Tannin Levels in Populus tremula Impact the Way Nitrogen Enrichment Affects Growth and Allocation Responses for Some Traits and Not for Others.

    Science.gov (United States)

    Bandau, Franziska; Decker, Vicki Huizu Guo; Gundale, Michael J; Albrectsen, Benedicte Riber

    2015-01-01

    Plant intraspecific variability has been proposed as a key mechanism by which plants adapt to environmental change. In boreal forests where nitrogen availability is strongly limited, nitrogen addition happens indirectly through atmospheric N deposition and directly through industrial forest fertilization. These anthropogenic inputs of N have numerous environmental consequences, including shifts in plant species composition and reductions in plant species diversity. However, we know less about how genetic differences within plant populations determine how species respond to eutrophication in boreal forests. According to plant defense theories, nitrogen addition will cause plants to shift carbon allocation more towards growth and less to chemical defense, potentially enhancing vulnerability to antagonists. Aspens are keystone species in boreal forests that produce condensed tannins to serve as chemical defense. We conducted an experiment using ten Populus tremula genotypes from the Swedish Aspen Collection that express extreme levels of baseline investment into foliar condensed tannins. We investigated whether investment into growth and phenolic defense compounds in young plants varied in response to two nitrogen addition levels, corresponding to atmospheric N deposition and industrial forest fertilization. Nitrogen addition generally caused growth to increase, and tannin levels to decrease; however, individualistic responses among genotypes were found for height growth, biomass of specific tissues, root:shoot ratios, and tissue lignin and N concentrations. A genotype's baseline ability to produce and store condensed tannins also influenced plant responses to N, although this effect was relatively minor. High-tannin genotypes tended to grow less biomass under low nitrogen levels and more at the highest fertilization level. Thus, the ability in aspen to produce foliar tannins is likely associated with a steeper reaction norm of growth responses, which suggests a

  18. Anthocyanins of the anthers as chemotaxonomic markers in the genus Populus L.. Differentiation between Populus nigra, Populus alba and Populus tremula.

    Science.gov (United States)

    Alcalde-Eon, Cristina; García-Estévez, Ignacio; Rivas-Gonzalo, Julián C; Rodríguez de la Cruz, David; Escribano-Bailón, María Teresa

    2016-08-01

    Three main species of Popululs L. (Salicaceae) have been reported to occur in the Iberian Peninsula: Populus nigra L., Populus alba L. and Populus tremula L. The degree of pilosity of the bracts of the male catkins is a key character for their differentiation. The anthers of these poplar species possess anthocyanins that provide them a red colouration. Since these poplars are wind-pollinated and, consequently, do not need to attract pollinators, anthocyanins in the anthers might be acting as photoprotectors, shielding pollen grains from excessive sunlight. In order to verify this hypothesis, the first objective of this study was to establish if there is any relationship between the degree of pilosity of the bracts (related to the physical shading of the pollen grains) and the levels and types of anthocyanins in the anthers of these three species. This study also aimed to check the usefulness of the anthocyanins of the anthers as chemotaxonomic markers, through the study of the differences in the anthocyanin composition between these poplar species. Anthocyanins were identified from the data supplied by HPLC-DAD-MS(n) analyses. Seventeen different compounds, including mono-, di- and triglycosides and anthocyanin-derived pigments (F-A(+) dimers) have been identified. Cyanidin 3-O-glucoside was the major compound in all the samples (>60% of the total content), which may be in accordance with the photoprotective role proposed for them. However, qualitative and quantitative differences were detected among samples. Cyanidin and delphinidin 3-O-sambubiosides have been detected only in the anthers of P. tremula as well as cyanidin 3-O-(2″-O-xyloxyl)rutinoside, making them valuable chemotaxonomic markers for this species. Hierarchical Cluster and Principal Components Analyses (HCA and PCA) carried out with the anthocyanin percent composition data have allowed a separation of the samples that is in accordance with the initial classification of the samples made from the

  19. Using Aspen plus in thermodynamics instruction a step-by-step guide

    CERN Document Server

    Sandler, Stanley I

    2015-01-01

    A step-by-step guide for students (and faculty) on the use of Aspen in teaching thermodynamics Used for a wide variety of important engineering tasks, Aspen Plus software is a modeling tool used for conceptual design, optimization, and performance monitoring of chemical processes. After more than twenty years, it remains one of the most popular and powerful chemical engineering simulation programs used both industrially and academically. Using Aspen Plus in Thermodynamics Instruction: A Step by Step Guide introduces the reader to the use of Aspen Plus in courses in thermodynamics. It prov

  20. [Chemical constituents contained in Populus tomentosa].

    Science.gov (United States)

    Liu, Haiping; Chao, Zhimao; Wu, Xiaoyi; Tan, Zhigao; Wang, Chun; Sun, Wen

    2012-05-01

    To separate and identify chemical constituents from stem barks of male plants of Populus tomentosa. Fresh stem barks of P. tomentosa were extracted with methanol to obtain extracts which were suspended in water and blended successively with petroleum ether, ethyl acetate and n-butanol. Various chromatographic techniques were used to separate and purify the constituents extracted with ethyl acetate and n-butanol fractions. Their structures were identified on the basis of their physicochemical properties and spectral data. Twelve compounds were separated with ethyl acetate and n-butanol fractions and identified as benzoic acid (1), daucosterol (2), tremuloidin (3), rhamnocitrin (4), sakuranetin (5), 7-O-methylaromadendrin (6), isograndidentatin A (7), siebolside B (8), sakuranin (9), micranthoside (10), alpha-D-glucopyranose (11), and sucrose (12). Compounds 4-12 were separated from this plant for the first time. Of them, compound 10 was separated from this plant genus for the first time.

  1. 2012 Aspen Winter Conferences on High Energy and Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Olivier, Dore [California Inst. of Technology (CalTech), Pasadena, CA (United States); Fox, Patrick [Aspen Center for Physics, CO (United States); Furic, Ivan [Univ. of Florida, Gainesville, FL (United States); Halkiadakis, Eva [Rutgers Univ., Piscataway, NJ (United States); Schmidt, Fabian [California Inst. of Technology (CalTech), Pasadena, CA (United States); Senatore, Leonardo [Stanford Univ., CA (United States); Smith, Kendrick M. [Princeton Univ., NJ (United States); Whiteson, Daniel [Univ. of California, Irvine, CA (United States)

    2012-05-01

    Aspen Center for Physics Project Summary DE-SC0007313 Budget Period: 1/1/2012 to 12/31/2012 The Hunt for New Particles, from the Alps to the Plains to the Rockies The 2012 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 11 to February 17, 2012. Sixty-seven participants from nine countries, and several universities and national labs attended the workshop titled, The Hunt for New Particles, from the Alps to the Plains to the Rockies. There were 53 formal talks, and a considerable number of informal discussions held during the week. The weeks events included a public lecture-Hunting the Dark Universe given by Neal Weiner from New York University) and attended by 237 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists conducted by Spencer Chang (University of Oregon), Matthew Reece (Harvard University) and Julia Shelton (Yale University) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by John Campbell (Fermilab), Patrick Fox (Fermilab), Ivan Furic (University of Florida), Eva Halkiadakis (Rutgers University) and Daniel Whiteson (University of California Irvine). Additional information is available at http://indico.cern.ch/conferenceDisplay.py?confId=143360. Inflationary Theory and its Confrontation with Data in the Planck Era The 2012 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was Inflationary Theory and its Confrontation with Data in the Planck Era. It was held from January 30 to February 4, 2012. The 62 participants came from 7 countries and attended 43 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists

  2. Design and simulation of heat exchangers using Aspen HYSYS, and Aspen exchanger design and rating for paddy drying application

    Science.gov (United States)

    Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.

    2016-06-01

    Air heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized air heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat air for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen Exchanger Design and Rating (EDR) to generate heat exchanger design and costs. The designs include shell and tubes and plate heat exchanger. The heat exchanger was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of air with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat exchanger were found to be plate heat exchanger with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM air flow rate.

  3. Metabolite profiles of Populus in response to pathogen stress.

    Science.gov (United States)

    Wu, Qiuming; Chen, Min; Zhou, Hailong; Zhou, Xianqing; Wang, Yanwei

    2015-09-25

    Populus canker is a widespread disease that seriously affects the growth and productivity of trees, and may even cause tree death. To assess the metabolic changes in Populus in response to pathogen stress, Populus stems infected or not with Dothiorella gregaria were analyzed by GC-MS. A total of 4, 051 features were detected and 44 metabolites were identified to be changed significantly in Populus upon infection. The identified responsive metabolites include saccharides, alcohols, organic acids, and amino acids and some secondary metabolites and most of the metabolites were detected at increased levels. Responsive metabolites were investigated about their metabolism pathway and the corresponding metabolic networks were further constructed. To our knowledge, this is the first study to identify the metabolite profiles of Populus in response to pathogen stress. The results extend our understanding of the mechanisms involved in the defense of Populus against pathogens and provide a basis for further research on plant defenses. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Simulation of Quaking Aspen Potential Fire Behavior in Northern Utah, USA

    Directory of Open Access Journals (Sweden)

    R. Justin DeRose

    2014-12-01

    Full Text Available Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread and torching (surface to crown fire spread were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion of aspen in the stand. Results showed a strong effect of species composition on crowning, but only under moderate fire weather, where aspen-dominated stands were unlikely to crown or torch. Although rarely observed in actual fires, conifer-dominated stands were likely to crown but not to torch, an example of “hysteresis” in crown fire behavior. Results support the hypothesis that potential crown fire behavior varies across a gradient of aspen dominance and fire weather, where it was likely under extreme and severe fire weather, and unlikely under moderate and high fire weather. Furthermore, the “fire-proof” nature of aspen stands broke down across the gradient of aspen dominance and fire weather.

  5. Harvesting Impacts on Soil Properties and Tree Regeneration in Pure and Mixed Aspen Stands

    Science.gov (United States)

    Melissa J. Arikian; Kiaus J. Peuttmann; Alaina L. Davis; George E. Host; John Zasada

    1999-01-01

    Impacts of clearcutting and selective harvesting on pure aspen/mixed aspen hardwood stands were examined in northern Minnesota. We studied these impacts on 18 stands, which were harvested 4 to 11 years ago and received no further treatment. In each stand, residual composition, soil compaction, and tree regeneration were determined along a gradient of disturbance in the...

  6. The effect of aspen harvest and growth on water yield in Minnesota

    Science.gov (United States)

    Elon S. Verry

    1987-01-01

    Annual water yield increased following the clearcutting of a mature aspen forest in years 1-9 and year 14 of subsequent aspen regrowth. Maximum increases of 85, 117, and 88 mm year-l occurred during the first 3 years of regrowth. Increases in streamflow volumes from snowmelt and early spring rains were minimal and more variable after harvest and...

  7. Scaling Aspen-FACE experimental results to century and landscape scales

    Science.gov (United States)

    Eric J. Gustafson; Mark E. Kubiske; Brian R. Sturtevant; Brian R. Miranda

    2013-01-01

    The Aspen-FACE experiment generated 11 years of empirical data on the effect of CO2 enrichment and elevated ozone on the growth of field-grown trees (maple, birch and six aspen clones) in northern Wisconsin, but it is not known how these short-term plot-level responses might play out at the landscape scale over multiple decades where competition...

  8. Revisiting the sequencing of the first tree genome: Populus trichocarpa.

    Science.gov (United States)

    Wullschleger, Stan D; Weston, D J; DiFazio, S P; Tuskan, G A

    2013-04-01

    Ten years ago, it was announced that the Joint Genome Institute with funds provided by the Department of Energy, Office of Science, Biological and Environmental Research would sequence the black cottonwood (Populus trichocarpa Torr. & Gray) genome. This landmark decision was the culmination of work by the forest science community to develop Populus as a model system. Since its public release in late 2006, the availability of the Populus genome has spawned research in plant biology, morphology, genetics and ecology. Here we address how the tree physiologist has used this resource. More specifically, we revisit our earlier contention that the rewards of sequencing the Populus genome would depend on how quickly scientists working with woody perennials could adopt molecular approaches to investigate the mechanistic underpinnings of basic physiological processes. Several examples illustrate the integration of functional and comparative genomics into the forest sciences, especially in areas that target improved understanding of the developmental differences between woody perennials and herbaceous annuals (e.g., phase transitions). Sequencing the Populus genome and the availability of genetic and genomic resources has also been instrumental in identifying candidate genes that underlie physiological and morphological traits of interest. Genome-enabled research has advanced our understanding of how phenotype and genotype are related and provided insights into the genetic mechanisms whereby woody perennials adapt to environmental stress. In the future, we anticipate that low-cost, high-throughput sequencing will continue to facilitate research in tree physiology and enhance our understanding at scales of individual organisms and populations. A challenge remains, however, as to how genomic resources, including the Populus genome, can be used to understand ecosystem function. Although examples are limited, progress in this area is encouraging and will undoubtedly improve as

  9. Newly identified helper bacteria stimulate ectomycorrhizal formation in Populus

    Directory of Open Access Journals (Sweden)

    Jessy L Labbé

    2014-10-01

    Full Text Available Mycorrhiza helper bacteria (MHB are known to increase host root colonization by mycorrhizal fungi but the molecular mechanisms and potential tripartite interactions are poorly understood. Through an effort to study Populus microbiome, we isolated 21 Pseudomonas strains from native Populus deltoides roots. These bacterial isolates were characterized and screened for MHB effectiveness on the Populus-Laccaria system. Two additional Pseudomonas strains (i.e., Pf-5 and BBc6R8 from existing collections were included for comparative purposes. We analyzed the effect of co-cultivation of these 23 individual Pseudomonas strains on Laccaria bicolor ‘S238N’ growth rate, mycelial architecture and transcriptional changes. Nineteen of the 23 Pseudomonas strains tested had positive effects on L. bicolor S238N growth, as well as on mycelial architecture, with strains GM41 and GM18 having the most significant effect. Four of seven L. bicolor reporter genes, Tra1, Tectonin2, Gcn5 and Cipc1, thought to be regulated during the interaction with MHB strain BBc6R8, were induced or repressed, while interacting with Pseudomonas strains GM17, GM33, GM41, GM48, Pf-5 and BBc6R8. Strain GM41 promoted the highest roots colonization across three Populus species but most notably in P. deltoides, which is otherwise poorly colonized by L. bicolor. Here we report novel MHB strains isolated from native Populus that improve L. bicolor root colonization on Populus. This tripartite relationship could be exploited for Populus species/genotypes nursery production as a means of improving establishment and survival in marginal lands.

  10. Biomass and genotype × environment interactions of Populus energy crops in the midwestern United States

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Richard B. Hall; Jill A. Zalesny; Bernard G. McMahon; William E. Berguson; Glen R. Stanosz

    2009-01-01

    Using Populus feedstocks for biofuels, bioenergy, and bioproducts is becoming economically feasible as global fossil fuel prices increase. Maximizing Populus biomass production across regional landscapes largely depends on understanding genotype × environment interactions, given broad genetic variation at strategic (...

  11. Highly Efficient Isolation of Populus Mesophyll Protoplasts and Its Application in Transient Expression Assays

    Science.gov (United States)

    Guo, Jianjun; Morrell-Falvey, Jennifer L.; Labbé, Jessy L.; Muchero, Wellington; Kalluri, Udaya C.; Tuskan, Gerald A.; Chen, Jin-Gui

    2012-01-01

    Background Populus is a model woody plant and a promising feedstock for lignocellulosic biofuel production. However, its lengthy life cycle impedes rapid characterization of gene function. Methodology/Principal Findings We optimized a Populus leaf mesophyll protoplast isolation protocol and established a Populus protoplast transient expression system. We demonstrated that Populus protoplasts are able to respond to hormonal stimuli and that a series of organelle markers are correctly localized in the Populus protoplasts. Furthermore, we showed that the Populus protoplast transient expression system is suitable for studying protein-protein interaction, gene activation, and cellular signaling events. Conclusions/Significance This study established a method for efficient isolation of protoplasts from Populus leaf and demonstrated the efficacy of using Populus protoplast transient expression assays as an in vivo system to characterize genes and pathways. PMID:23028673

  12. Effects of Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) Larval Defoliation, Clone, and Season on Populus Foliar Phagostimulants

    Science.gov (United States)

    David R. Coyle; Joel D. McMillin; Richard B. Hall; Elwood R. Hart

    2003-01-01

    Abstract: The cottonwood leaf beetle, Chrysomela scripta F., is a serious defoliator of plantation Populus in the United States. Current control methods include biorational and synthetic chemicals as well as selecting Populus clones resistant or tolerant to C. scripta...

  13. Interaction of nitrogen nutrition and salinity in Grey poplar (Populus tremula × alba)

    National Research Council Canada - National Science Library

    EHLTING, B; DLUZNIEWSKA, P; DIETRICH, H; SELLE, A; TEUBER, M; HÄNSCH, R; NEHLS, U; POLLE, A; SCHNITZLER, J.‐P; RENNENBERG, H; GESSLER, A

    2007-01-01

    ...‐rotation forestry in fertilized plantations and can be grown on saline soil. Because N fertilization plays an important role in salt tolerance, we analysed Grey poplar ( Populus tremula  ×  alba , syn. Populus canescens...

  14. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  15. Contrasting the patterns of aspen forest and sagebrush shrubland gross ecosystem exchange in montane Idaho, USA

    Science.gov (United States)

    Fellows, A.; Flerchinger, G. N.; Seyfried, M. S.

    2015-12-01

    We investigated the environmental controls on Gross Ecosystem Exchange (GEE) at an aspen forest and a sagebrush shrubland in southwest Idaho. The two sites were situated within a mosaic of vegetation that included temperate deciduous trees, shrublands, and evergreen conifer trees. The distribution of vegetation was presumably linked to water availability; aspen were located in wetter high-elevations sites, topographic drainages, or near snow drifts. Local temperatures have increased by ~2-3 °C over the past 50 years and less precipitation has arrived as snow. These ongoing changes in weather may impact snow water redistribution, plant-water availability, and plant-thermal stress, with associated impacts on vegetation health and production. We used eddy covariance to measure the exchange of water and carbon dioxide above the two sites and partitioned the net carbon flux to determine GEE. The sagebrush record was from 2003-2007 and the aspen record was from 2007-12. The region experienced a modest-to-severe drought in 2007, with ~73% of typical precipitation. We found that aspen were local "hotspots" for carbon exchange; peak rates of aspen GEE were ~ 60% greater than the peak rates of sagebrush GEE. Light, temperature, and water availability were dominant controls on the seasonality of GEE at both sites. Sagebrush and aspen were dormant during winter, limited by cold temperatures during winter and early spring, and water availability during mid-late summer. The onset of summer drought was typically later in the aspen than in the sagebrush. Drifting snow, lateral water redistribution, or increased rooting depths may have increased water availability in the aspen stand. Seasonal patterns of observed soil moisture and evaporation indicated aspen were rooted to >= 1 m. The sagebrush and aspen both responded strongly to the 2007 drought; peak GEE decreased by ~75%, peak GEE shifted to earlier parts of the year, and mid-summer GEE was decreased. We consider potential

  16. Repeated unidirectional introgression towards Populus balsamifera in contact zones of exotic and native poplars

    NARCIS (Netherlands)

    Thompson, S.L.; Lamothe, M.; Meirmans, P.G.; Périnet, P.; Isabel, N.

    2010-01-01

    As the evolutionary significance of hybridization is largely dictated by its extent beyond the first generation, we broadly surveyed patterns of introgression across a sympatric zone of two native poplars (Populus balsamifera, Populus deltoides) in Quebec, Canada within which European exotic Populus

  17. 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.

  18. Characterization of DWARF14 Genes in Populus

    Science.gov (United States)

    Zheng, Kaijie; Wang, Xiaoping; Weighill, Deborah A.; Guo, Hao-Bo; Xie, Meng; Yang, Yongil; Yang, Jun; Wang, Shucai; Jacobson, Daniel A.; Guo, Hong; Muchero, Wellington; Tuskan, Gerald A.; Chen, Jin-Gui

    2016-01-01

    Strigolactones are a new class of plant hormones regulating shoot branching and symbiotic interactions with arbuscular mycorrhizal fungi. Studies of branching mutants in herbaceous plants have identified several key genes involved in strigolactone biosynthesis or signaling. The strigolactone signal is perceived by a member of the α/β-fold hydrolase superfamily, known as DWARF14 (D14). However, little is known about D14 genes in the woody perennial plants. Here we report the identification of D14 homologs in the model woody plant Populus trichocarpa. We showed that there are two D14 homologs in P. trichocarpa, designated as PtD14a and PtD14b that are over 95% similar at the amino acid level. Expression analysis indicated that the transcript level of PtD14a is generally more abundant than that of PtD14b. However, only PtD14a was able to complement Arabidopsis d14 mutants, suggesting that PtD14a is the functional D14 ortholog. Amino acid alignment and structural modeling revealed substitutions of several highly conserved amino acids in the PtD14b protein including a phenylalanine near the catalytic triad of D14 proteins. This study lays a foundation for further characterization of strigolactone pathway and its functions in the woody perennial plants. PMID:26875827

  19. Variable Nitrogen Fixation in Wild Populus.

    Directory of Open Access Journals (Sweden)

    Sharon L Doty

    Full Text Available The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees.

  20. Efficient Agrobacterium-Mediated Transformation of Hybrid Poplar Populus davidiana Dode × Populus bollena Lauche

    Directory of Open Access Journals (Sweden)

    Xue Han

    2013-01-01

    Full Text Available Poplar is a model organism for high in vitro regeneration in woody plants. We have chosen a hybrid poplar Populus davidiana Dode × Populus bollena Lauche. By optimizing the Murashige and Skoog medium with (0.3 mg/L 6-benzylaminopurine and (0.08 mg/L naphthaleneacetic acid, we have achieved the highest frequency (90% for shoot regeneration from poplar leaves. It was also important to improve the transformation efficiency of poplar for genetic breeding and other applications. In this study, we found a significant improvement of the transformation frequency by controlling the leaf age. Transformation efficiency was enhanced by optimizing the Agrobacterium concentration (OD600 = 0.8–1.0 and an infection time (20–30 min. According to transmission electron microscopy observations, there were more Agrobacterium invasions in the 30-day-old leaf explants than in 60-day-old and 90-day-old explants. Using the green fluorescent protein (GFP marker, the expression of MD–GFP fusion proteins in the leaf, shoot, and root of hybrid poplar P. davidiana Dode × P. bollena Lauche was visualized for confirmation of transgene integration. Southern and Northern blot analysis also showed the integration of T-DNA into the genome and gene expression of transgenic plants. Our results suggest that younger leaves had higher transformation efficiency (~30% than older leaves (10%.

  1. Defining hybrid poplar (Populus deltoides x Populus trichocarpa) tolerance to ozone: identifying key parameters.

    Science.gov (United States)

    Ryan, A; Cojocariu, C; Possell, M; Davies, W J; Hewitt, C N

    2009-01-01

    This study examined whether two genotypes of hybrid poplar (Populus deltoides x Populus trichocarpa), previously classified as ozone tolerant and ozone sensitive, had differing physiological and biochemical responses when fumigated with 120 nL L(-1) ozone for 6 h per day for eight consecutive days. Isoprene emission rate, ozone uptake and a number of physiological and biochemical parameters were investigated before, during and after fumigation with ozone. Previous studies have shown that isoprene protects plants against oxidative stress. Therefore, it was hypothesized that these two genotypes would differ in either their basal isoprene emission rates or in the response of isoprene to fumigation by ozone. Our results showed that the basal emission rates of isoprene, physiological responses and ozone uptake rates were all similar. However, significant differences were found in visible damage, carotenoids, hydrogen peroxide (H(2)O(2)), thiobarbituric acid reactions (TBARS) and post-fumigation isoprene emission rates. It is shown that, although the classification of ozone tolerance or sensitivity had been previously clearly and carefully defined using one particular set of parameters, assessment of other key variables does not necessarily lead to the same conclusions. Thus, it may be necessary to reconsider the way in which plants are classified as ozone tolerant or sensitive.

  2. Agrobacterium-mediated stable genetic transformation of Populus angustifolia and Populus balsamifera

    Directory of Open Access Journals (Sweden)

    Priti eMaheshwari

    2016-03-01

    Full Text Available The present study demonstrates Agrobacterium tumefaciens-mediated stable genetic transformation of two species of Poplar - Populus angustifolia and Populus balsamifera. The binary vector pCAMBIA-Npro-long-Luc containing the luciferase reporter gene was used to transform stem internode and axillary bud explants. Putative transformants were regenerated on selection-free medium using our previously established in vitro regeneration method. Explant type, genotype, effect of pre-culture, Agrobacterium concentration, a time period of infection and varying periods of co-culture with bacteria were tested for the transformation frequency. The highest frequency of transformation was obtained with stem internode explants pre-cultured for 2 days, infected with Agrobacterium culture at the concentration of OD600=0.5 for 10 min and co-cultivated with Agrobacterium for 48 h. Out of the two genotypes tested, P. balsamifera exhibited a higher transformation rate in comparison to P. angustifolia. The primary transformants that exhibited luciferase activity in a bioluminescence assay under the CCD camera when subjected to PCR and southern blot analysis revealed a stable single-copy integration of luc in their genomes. The reported protocol is highly reproducible and can be applied to other species of poplar; it will also be useful for future genetic engineering of one of the most important families of woody plants for sustainable development.

  3. Great Plains ASPEN model development: Phosam section. Final topical report

    Energy Technology Data Exchange (ETDEWEB)

    Stern, S S; Kirman, J J

    1985-02-01

    An ASPEN model has been developed of the PHOSAM Section, Section 4600, of the Great Plains Gasification Plant. The bases for this model are the process description given in Section 6.18 of the Great Plains Project Management Plan and the Lummus Phosam Schematic Process Flow Diagram, Dwg. No. SKD-7102-IM-O. The ASPEN model that has been developed contains the complete set of components that are assumed to be in the gasifier effluent. The model is primarily a flowsheet simulation that will give the material and energy balance and equipment duties for a given set of process conditions. The model is unable to predict fully changes in process conditions that would result from load changes on equipment of fixed sizes, such as a rating model would predict. The model can be used to simulate the steady-state operation of the plant at or near design conditions or to design other PHOSAM units. Because of the limited amount of process information that was available, several major process assumptions had to be made in the development of the flowsheet model. Patent literature was consulted to establish the ammonia concentration in the circulating fluid. Case studies were made with the ammonia content of the feed 25% higher and 25% lower than the base feed. Results of these runs show slightly lower recoveries of ammonia with less ammonia in the feed. As expected, the duties of the Stripper and Fractionator reboilers were higher with more ammonia in the feed. 63 references.

  4. The glutamine synthetase gene family in Populus

    Directory of Open Access Journals (Sweden)

    Cánovas Francisco M

    2011-08-01

    Full Text Available Abstract Background Glutamine synthetase (GS; EC: 6.3.1.2, L-glutamate: ammonia ligase ADP-forming is a key enzyme in ammonium assimilation and metabolism of higher plants. The current work was undertaken to develop a more comprehensive understanding of molecular and biochemical features of GS gene family in poplar, and to characterize the developmental regulation of GS expression in various tissues and at various times during the poplar perennial growth. Results The GS gene family consists of 8 different genes exhibiting all structural and regulatory elements consistent with their roles as functional genes. Our results indicate that the family members are organized in 4 groups of duplicated genes, 3 of which code for cytosolic GS isoforms (GS1 and 1 which codes for the choroplastic GS isoform (GS2. Our analysis shows that Populus trichocarpa is the first plant species in which it was observed the complete GS family duplicated. Detailed expression analyses have revealed specific spatial and seasonal patterns of GS expression in poplar. These data provide insights into the metabolic function of GS isoforms in poplar and pave the way for future functional studies. Conclusions Our data suggest that GS duplicates could have been retained in order to increase the amount of enzyme in a particular cell type. This possibility could contribute to the homeostasis of nitrogen metabolism in functions associated to changes in glutamine-derived metabolic products. The presence of duplicated GS genes in poplar could also contribute to diversification of the enzymatic properties for a particular GS isoform through the assembly of GS polypeptides into homo oligomeric and/or hetero oligomeric holoenzymes in specific cell types.

  5. Genomics of Secondary Metabolism in Populus: Interactions with Biotic and Abiotic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Liu, C.; Tschaplinski, T. J.; Zhao, N.

    2009-09-01

    Populus trees face constant challenges from the environment during their life cycle. To ensure their survival and reproduction, Populus trees deploy various types of defenses, one of which is the production of a myriad of secondary metabolites. Compounds derived from the shikimate-phenylpropanoid pathway are the most abundant class of secondary metabolites synthesized in Populus. Among other major classes of secondary metabolites in Populus are terpenoids and fatty acid-derivatives. Some of the secondary metabolites made by Populus trees have been functionally characterized. Some others have been associated with certain biological/ecological processes, such as defense against insects and microbial pathogens or acclimation or adaptation to abiotic stresses. Functions of many Populus secondary metabolites remain unclear. The advent of various novel genomic tools will enable us to explore in greater detail the complexity of secondary metabolism in Populus. Detailed data mining of the Populus genome sequence can unveil candidate genes of secondary metabolism. Metabolomic analysis will continue to identify new metabolites synthesized in Populus. Integrated genomics that combines various 'omics' tools will prove to be the most powerful approach in revealing the molecular and biochemical basis underlying the biosynthesis of secondary metabolites in Populus. Characterization of the biological/ecological functions of secondary metabolites as well as their biosynthesis will provide knowledge and tools for genetically engineering the production of seconday metabolites that can lead to the generation of novel, improved Populus varieties.

  6. Establishment of Alleycropped Hybrid Aspen “Crandon” in Central Iowa, USA: Effects of Topographic Position and Fertilizer Rate on Aboveground Biomass Production and Allocation

    Directory of Open Access Journals (Sweden)

    Richard B. Hall

    2013-07-01

    Full Text Available Hybrid poplars have demonstrated high productivity as short rotation woody crops (SRWC in the Midwest USA, and the hybrid aspen “Crandon” (Populus alba L. × P. grandidenta Michx. has exhibited particularly promising yields on marginal lands. However, a key obstacle for wider deployment is the lack of economic returns early in the rotation. Alleycropping has the potential to address this issue, especially when paired with crops such as winter triticale which complete their growth cycle early in the summer and therefore are expected to exert minimal competition on establishing trees. In addition, well-placed fertilizer in low rates at planting has the potential to improve tree establishment and shorten the rotation, which is also economically desirable. To test the potential productivity of “Crandon” alleycropped with winter triticale, plots were established on five topographic positions with four different rates of fertilizer placed in the planting hole. Trees were then harvested from the plots after each of the first three growing seasons. Fertilization resulted in significant increases in branch, stem, and total aboveground biomass across all years, whereas the effects of topographic position varied by year. Allocation between branches and stems was found to be primarily a function of total aboveground biomass.

  7. Assessment of Populus wood chemistry following the introduction of a Bt toxin gene

    Energy Technology Data Exchange (ETDEWEB)

    Tschaplinski, Timothy J [ORNL; Davis, M F [National Energy Renewable Laboratory; Tuskan, Gerald A [ORNL; Payne, M M [Boise Cascade LLC; Meilan, R [Purdue University

    2006-01-01

    Unintended changes in plant physiology, anatomy and metabolism as a result of genetic engineering are a concern as more transgenic plants are commercially deployed in the ecosystem. We compared the cell wall chemical composition of three Populus lines (Populus trichocarpa Torr. & A. Gray x Populus trichocarpa Bartr. ex Marsh., Populus trichocarpa x Populus nigra L. and Populus deltoides x Populus nigra) genetically modified to express the Cry3A or Cry3B2 protein of Bacillus thuringiensis (Bt) with the cell wall chemistry of non-transformed isogenic control lines. Three genetically modified clones, each represented by 10 independent transgenic lines, were analyzed by pyrolysis molecular beam mass spectrometry, gas chromatography/mass spectrometry and traditional wet chemical analytical methods to assess changes in cell wall composition. Based on the outcome of these techniques, there were no comprehensive differences in chemical composition between the transgenic and control lines for any of the studied clones.

  8. Assessment of Populus Wood Chemistry Following the Introduction of a Bt Toxin Gene

    Energy Technology Data Exchange (ETDEWEB)

    Davis, M. F.; Tuskan, G. A.; Payne, P.; Tschaplinski, T. J.; Meilan, R.

    2006-01-01

    Unintended changes in plant physiology, anatomy and metabolism as a result of genetic engineering are a concern as more transgenic plants are commercially deployed in the ecosystem. We compared the cell wall chemical composition of three Populus lines (Populus trichocarpa Torr. and A. Gray x Populus deltoides Bartr. ex Marsh., Populus trichocarpa x Populus nigra L. and Populus deltoides x Populus nigra) genetically modified to express the Cry3A or Cry3B2 protein of Bacillus thuringiensis (Bt) with the cellwall chemistry of non-transformed isogenic control lines. Three genetically modified clones, each represented by 10 independent transgenic lines, were analyzed by pyrolysis molecular beam mass spectrometry, gas chromatography/mass spectrometry and traditional wet chemical analytical methods to assess changes in cell wall composition. Based on the outcome of these techniques, there were no comprehensive differences in chemical composition between the transgenic and control lines for any of the studied clones.

  9. Orbital Express Mission Operations Planning and Resource Management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Danny

    2008-01-01

    The Orbital Express satellite servicing demonstrator program is a DARPA program aimed at developing "a safe and cost-effective approach to autonomously service satellites in orbit". The system consists of: a) the Autonomous Space Transport Robotic Operations (ASTRO) vehicle, under development by Boeing Integrated Defense Systems, and b) a prototype modular next-generation serviceable satellite, NEXTSat, being developed by Ball Aerospace. Flexibility of ASPEN: a) Accommodate changes to procedures; b) Accommodate changes to daily losses and gains; c) Responsive re-planning; and d) Critical to success of mission planning Auto-Generation of activity models: a) Created plans quickly; b) Repetition/Re-use of models each day; and c) Guarantees the AML syntax. One SRP per day vs. Tactical team

  10. The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

    Science.gov (United States)

    G.A. Tuskan; S. DiFazio; S. Jansson; J. Bohlmann; I. Grigoriev; U. Hellsten; N. Putnam; S. Ralph; S. Rombauts; A. Salamov; J. Schein; L. Sterck; A. Aerts; R.R. Bhalerao; R.P. Bhalerao; D. Blaudez; W. Boerjan; A. Brun; A. Brunner; V. Busov; M. Campbell; J. Carlson; M. Chalot; J. Chapman; G.-L. Chen; D. Cooper; P.M. Coutinho; J. Couturier; S. Covert; Q. Cronk; R. Cunningham; J. Davis; S. Degroeve; A. Dejardin; C. dePamphilis; J. Detter; B. Dirks; U. Dubchak; S. Duplessis; J. Ehlting; B. Ellis; K. Gendler; D. Goodstein; M. Gribskov; J. Grimwood; A. Groover; L. Gunter; B. Hamberger; B. Heinze; Y. Helariutta; B. Henrissat; D. Holligan; R. Holt; W. Huang; N. Islam-Faridi; S. Jones; M. Jones-Rhoades; R. Jorgensen; C. Joshi; J. Kangasjarvi; J. Karlsson; C. Kelleher; R. Kirkpatrick; M. Kirst; A. Kohler; U. Kalluri; F. Larimer; J. Leebens-Mack; J.-C. Leple; P. Locascio; Y. Lou; S. Lucas; F. Martin; B. Montanini; C. Napoli; D.R. Nelson; C. Nelson; K. Nieminen; O. Nilsson; V. Pereda; G. Peter; R. Philippe; G. Pilate; A. Poliakov; J. Razumovskaya; P. Richardson; C. Rinaldi; K. Ritland; P. Rouze; D. Ryaboy; J. Schumtz; J. Schrader; B. Segerman; H. Shin; A. Siddiqui; F. Sterky; A. Terry; C.-J. Tsai; E. Uberbacher; P. Unneberg; J. Vahala; K. Wall; S. Wessler; G. Yang; T. Yin; C. Douglas; M. Marra; G. Sandberg; Y. Van de Peer; D. Rokhsar

    2006-01-01

    We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs...

  11. Drought induces alterations in the stomatal development program in Populus

    Science.gov (United States)

    Campbell, Malcolm M

    2012-01-01

    Much is known about the physiological control of stomatal aperture as a means by which plants adjust to water availability. By contrast, the role played by the modulation of stomatal development to limit water loss has received much less attention. The control of stomatal development in response to water deprivation in the genus Populus is explored here. Drought induced declines in stomatal conductance as well as an alteration in stomatal development in two genotypes of Populus balsamifera. Leaves that developed under water-deficit conditions had lower stomatal indices than leaves that developed under well-watered conditions. Transcript abundance of genes that could hypothetically underpin drought-responsive changes in stomatal development was examined, in two genotypes, across six time points, under two conditions, well-watered and with water deficit. Populus homologues of STOMAGEN, ERECTA (ER), STOMATA DENSITY AND DISTRIBUTION 1 (SDD1), and FAMA had variable transcript abundance patterns congruent with their role in the modulation of stomatal development in response to drought. Conversely, there was no significant variation in transcript abundance between genotypes or treatments for the Populus homologues of YODA (YDA) and TOO MANY MOUTHS (TMM). The findings highlight the role that could be played by stomatal development during leaf expansion as a longer term means by which to limit water loss from leaves. Moreover, the results point to the key roles played by the regulation of the homologues of STOMAGEN, ER, SDD1, and FAMA in the control of this response in poplar. PMID:22760471

  12. Pathogenicity of Cytospora, Phomopsis, and Hypomyces on Populus deltoides

    Science.gov (United States)

    T. H. Filer

    1967-01-01

    Cytospora chrysosperma, Phomopsis macrospora, and Hypomyces solani are pathogenic on cottonwood (Populus deltoides). These canker-causing fungi were most virulent in November, when rains were frequent and temperatures were between 20 and 30 C. Trees growing on an unfavorable site were more susceptible to

  13. Micropropagation, genetic engineering, and molecular biology of Populus

    Science.gov (United States)

    N. B. Klopfenstein; Y. W. Chun; M. -S. Kim; M. A. Ahuja; M. C. Dillon; R. C. Carman; L. G. Eskew

    1997-01-01

    Thirty-four Populus biotechnology chapters, written by 85 authors, are comprised in 5 sections: 1) in vitro culture (micropropagation, somatic embryogenesis, protoplasts, somaclonal variation, and germplasm preservation); 2) transformation and foreign gene expression; 3) molecular biology (molecular/genetic characterization); 4) biotic and abiotic resistance (disease,...

  14. Shoot Morphogenesis Associated With Flowering in Populus deltoides (Salicaceae)

    Science.gov (United States)

    Cetin Yuceer; Samuel B. Land; Mark E. Kubiske; Richard L. Harkess

    2003-01-01

    Temporal and spatial formation and differentiation of axillary buds in developing shoots of mature eastern cottonwood (Populus deltoides) were investigated. Shoots sequentially initiate early vegetative, floral, and late vegetative buds. Associated with these buds is the formation of three distinct leaf types. In May of the first growing season, the...

  15. Genome structure and primitive sex chromosome revealed in Populus

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL; Gunter, Lee E [ORNL; Blaudez, D [UMR, France

    2008-01-01

    We constructed a comprehensive genetic map for Populus and ordered 332 Mb of sequence scaffolds along the 19 haploid chromosomes in order to compare chromosomal regions among diverse members of the genus. These efforts lead us to conclude that chromosome XIX in Populus is evolving into a sex chromosome. Consistent segregation distortion in favor of the sub-genera Tacamahaca alleles provided evidence of divergent selection among species, particularly at the proximal end of chromosome XIX. A large microsatellite marker (SSR) cluster was detected in the distorted region even though the genome-wide distribute SSR sites was uniform across the physical map. The differences between the genetic map and physical sequence data suggested recombination suppression was occurring in the distorted region. A gender-determination locus and an overabundance of NBS-LRR genes were also co-located to the distorted region and were put forth as the cause for divergent selection and recombination suppression. This hypothesis was verified by using fine-scale mapping of an integrated scaffold in the vicinity of the gender-determination locus. As such it appears that chromosome XIX in Populus is in the process of evolving from an autosome into a sex chromosome and that NBS-LRR genes may play important role in the chromosomal diversification process in Populus.

  16. Successful grafting in poplar species (Populus spp.) breeding

    Science.gov (United States)

    A. Assibi Mahama; Brian Sparks; Ronald S., Zalesny; Richard B. Hall

    2006-01-01

    Poor rooting of Populus deltoides Bartr. ex Marsh hardwood cuttings often has contributed to delays in breeding progress as a result of failures of scion wood before and/or after pollination. Seventeen clones were used, and the study was conducted in the greenhouse to test an "intervenous feeding" (IV) method, along with three different...

  17. Generalized height-diameter models for Populus tremula L. stands ...

    African Journals Online (AJOL)

    Using permanent sample plot data, selected tree height and diameter functions were evaluated for their predictive abilities for Populus tremula stands in Turkey. Two sets of models were evaluated. The first set included five models for estimating height as a function of individual tree diameter; the second set also included six ...

  18. Generalized height-diameter models for Populus tremula L. stands

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... recommended for estimating tree heights for P. tremula L. in Turkey. The model coefficients are documented for future use. Key words: Schnute's function, h-d models, Populus tremula L. INTRODUCTION. Individual tree heights and diameters are essential measurement in forest inventories and are used for.

  19. Trinucleotide repeat microsatellite markers for Black Poplar (Populus nigra L.)

    NARCIS (Netherlands)

    Smulders, M.J.M.; Schoot, van der J.; Arens, P.; Vosman, B.

    2001-01-01

    Using an enrichment procedure, we have cloned microsatellite repeats from black poplar (Populus nigra L.) and developed primers for microsatellite marker analysis. Ten primer pairs, mostly for trinucleotide repeats, produced polymorphic fragments in P. nigra. Some of them also showed amplification

  20. Genomewide analysis of the chitinase gene family in Populus ...

    Indian Academy of Sciences (India)

    2013-04-02

    Apr 2, 2013 ... class II chitinase genes, was induced by methyl jasmonate. (MeJA) rather than other treatments. POPTR_0012s01150.1 is a class III chitinase gene. It was sensitive to elicitor and wound inducements but insensitive to salicylid acid. (SA) and MeJA treatments. When Populus was infected by. M. brunnea, the ...

  1. Populus galls induced by Pemphigus aphids in Sinai Somia El ...

    African Journals Online (AJOL)

    El Harmeen Press, Cairo. Egyptian British Biological Society (EBB Soc)_. Populus galls induced by Pemphigus aphids in Sinai. Somia El-Akkad“ and Samy Zalat2. 1. Department of Botany, Faculty of Science, Ain Shams University, Cairo, Egypt. 2. Department of Zoology, Faculty of Science, Suez Canal University, Ismailia, ...

  2. Creation and genomic analysis of irradiation hybrids in Populus

    Science.gov (United States)

    Matthew S. Zinkgraf; K. Haiby; M.C. Lieberman; L. Comai; I.M. Henry; Andrew Groover

    2016-01-01

    Establishing efficient functional genomic systems for creating and characterizing genetic variation in forest trees is challenging. Here we describe protocols for creating novel gene-dosage variation in Populus through gamma-irradiation of pollen, followed by genomic analysis to identify chromosomal regions that have been deleted or inserted in...

  3. Impact of ozone on understory plants of the aspen zone

    Energy Technology Data Exchange (ETDEWEB)

    Harward, M.R.; Treshow, M.

    1971-01-01

    The purpose of this study was to learn how ozone might affect the growth and reproduction of understory species of the aspen community, and thereby influence its stability and composition. Plants of 15 representative species of the aspen community were grown in chambers and fumigated 4 hours each day, 5 days per week throughout their growing seasons. These included: Achillea millifolium, Chenopodium album, Chenopodium fremontii, Cruciferae sp., Descurainia pinnata, Descurainia sp., Geranium fremontii, Isatis tinctoria, Ligusticum porteri, Lepidium virginicum, Madia glomerata, Polygonum aviculare, Polygonum douglasii, Phacelia heterophylla, Viola italica. Plants were exposed to 30 pphm, 15 pphm, ambient air reaching 5-7 pphm for 2 hours per day, and filtered air. The study was repeated for 3 seasons. Ambient air caused a significant reduction of total plant weight only of Lepidium virginicum. Six species produced fruit and seeds. At 15 pphm, seed production by Madia glomerata and Polygonum douglasii was significantly reduced. At 30 pphm, seed production was also reduced in Polygonum aviculare and Lepidium virginicum. The two most significant conclusions to emerge from the study were first that several species were more sensitive to ozone than might have been suspected. Second, this sensitivity varied sufficiently that major shifts in community composition would be probable following only a year or two of exposure. More tolerant species have no doubt already become dominant over more sensitive species in natural plant communities exposed to elevated ozone concentrations. It must be stressed that the species studied did not necessarily represent the most ozone sensitive members of the community, or the most tolerant.

  4. Thermochemical Equilibrium Model of Synthetic Natural Gas Production from Coal Gasification Using Aspen Plus

    National Research Council Canada - National Science Library

    Barrera, Rolando; Salazar, Carlos; Pérez, Juan F

    2014-01-01

    .... The model was developed using a complete and comprehensive Aspen Plus model. Two typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated...

  5. Best Practices Case Study: Shaw Construction Burlingame Ranch Ph.1, Aspen, CO

    Energy Technology Data Exchange (ETDEWEB)

    Pacific Northwest National Laboratory & Oak Ridge National Laboratory

    2010-12-01

    Shaw Construction built 84 energy efficient, affordable condominiums forthe City of Aspen that achieved HERS scores of less than 62 with help from Building America’s research team lead Building Science Corporation.

  6. Thinning Pole-Sized Aspen Has no Effect on Number of Veneer Trees or Total Yield

    Science.gov (United States)

    Bryce E. Schlaegel; Stanley B. Ringlod

    1971-01-01

    Thinning 37-year-old aspen in north central Minnesota did not increase either total volume production or the number of veneer-sized trees after 10 years. Thinning is not recommended for stands nearing rotation age.

  7. Evolutionary Quantitative Genomics of Populus trichocarpa.

    Directory of Open Access Journals (Sweden)

    Ilga Porth

    Full Text Available Forest trees generally show high levels of local adaptation and efforts focusing on understanding adaptation to climate will be crucial for species survival and management. Here, we address fundamental questions regarding the molecular basis of adaptation in undomesticated forest tree populations to past climatic environments by employing an integrative quantitative genetics and landscape genomics approach. Using this comprehensive approach, we studied the molecular basis of climate adaptation in 433 Populus trichocarpa (black cottonwood genotypes originating across western North America. Variation in 74 field-assessed traits (growth, ecophysiology, phenology, leaf stomata, wood, and disease resistance was investigated for signatures of selection (comparing QST-FST using clustering of individuals by climate of origin (temperature and precipitation. 29,354 SNPs were investigated employing three different outlier detection methods and marker-inferred relatedness was estimated to obtain the narrow-sense estimate of population differentiation in wild populations. In addition, we compared our results with previously assessed selection of candidate SNPs using the 25 topographical units (drainages across the P. trichocarpa sampling range as population groupings. Narrow-sense QST for 53% of distinct field traits was significantly divergent from expectations of neutrality (indicating adaptive trait variation; 2,855 SNPs showed signals of diversifying selection and of these, 118 SNPs (within 81 genes were associated with adaptive traits (based on significant QST. Many SNPs were putatively pleiotropic for functionally uncorrelated adaptive traits, such as autumn phenology, height, and disease resistance. Evolutionary quantitative genomics in P. trichocarpa provides an enhanced understanding regarding the molecular basis of climate-driven selection in forest trees and we highlight that important loci underlying adaptive trait variation also show

  8. Identification and characterization of the Populus sucrose synthase gene family.

    Science.gov (United States)

    An, Xinmin; Chen, Zhong; Wang, Jingcheng; Ye, Meixia; Ji, Lexiang; Wang, Jia; Liao, Weihua; Ma, Huandi

    2014-04-10

    In this study, we indentified 15 sucrose synthase (SS) genes in Populus and the results of RT-qPCR revealed that their expression patterns were constitutive and partially overlapping but diverse. The release of the most recent Populus genomic data in Phytozome v9.1 has revealed the largest SS gene family described to date, comprising 15 distinct members. This information will now enable the analysis of transcript expression profiles for those that have not been previously reported. Here, we performed a comprehensive analysis of SS genes in Populus by describing the gene structure, chromosomal location and phylogenetic relationship of each family member. A total of 15 putative SS gene members were identified in the Populus trichocarpa (Torr. & Gray) genome using the SS domain and amino acid sequences from Arabidopsis thaliana as a probe. A phylogenetic analysis indicated that the 15 members could be classified into four groups that fall into three major categories: dicots, monocots & dicots 1 (M & D 1), and monocots & dicots 2 (M & D 2). In addition, the 15 SS genes were found to be unevenly distributed on seven chromosomes. The two conserved domains (sucrose synthase and glycosyl transferase) were found in this family. Meanwhile, the expression profiles of all 15 gene members in seven different organs were investigated in Populus tomentosa (Carr.) by using RT-qPCR. Additional analysis indicated that the poplar SS gene family is also involved in response to water-deficit. The current study provides basic information that will assist in elucidating the functions of poplar SS family. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Heartrot fungi's role in creating picid nesting sites in living aspen

    Science.gov (United States)

    John H. Hart; D. L. Hart

    2001-01-01

    To determine the number of cavity-containing aspens in old-growth (>80 years), we counted the number of stems containing cavities in 132 0.02-ha plots in Wyoming. There were 8.7 cavities/ha of aspen type. At least 84% of the cavity stems were alive when the initial cavity was constructed; 60% were alive when examined. Fruiting bodies and Phellinus tremulae (a...

  10. Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.

    OpenAIRE

    KOEDUKA, Takao; Suzuki, Shiro; Iijima, Yoko; Ohnishi, Toshiyuki; Suzuki, Hideyuki; Watanabe, Bunta; Shibata, Daisuke; UMEZAWA, Toshiaki; Pichersky, Eran; Hiratake, Jun

    2013-01-01

    Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eug...

  11. Het geslacht Populus in verband met zijn beteekenis voor de houtteelt = The genus populus and its significance in silviculture

    NARCIS (Netherlands)

    Houtzagers, G.

    1937-01-01

    The genus Populus L. can be divided into 5 sections. This study deals with the classification and description of the species and varieties of the section Aigeiros Duby (black poplars), which contains almost all the important cultivated types in the Netherlands. The botanical information was

  12. Laboratory-scale measurements of N2O and CH4 emissions from hybrid poplars (Populus deltoides x Populus nigra).

    Science.gov (United States)

    McBain, M C; Warland, J S; McBride, R A; Wagner-Riddle, C

    2004-12-01

    The purpose of this study was to determine whether or not young hybrid poplar (Populus deltoides x Populus nigra) could transport landfill biogas internally from the root zone to the atmosphere, thereby acting as conduits for landfill gas release. Fluxes of methane (CH4) and nitrous oxide (N2O) from the seedlings to the atmosphere were measured under controlled conditions using dynamic flux chambers and a tunable diode laser trace gas analyser (TDLTGA). Nitrous oxide was emitted from the seedlings, but only when extremely high soil N2O concentrations were applied to the root zone. In contrast, no detectable emissions of CH4 were measured in a similar experimental trial. Visible plant morphological responses, characteristic of flood-tolerant trees attempting to cope with the negative effects of soil hypoxia, were observed during the CH4 experiments. Leaf chlorosis, leaf abscission and adventitious roots were all visible plant responses. In addition, seedling survival was observed to be highest in the biogas 'hot spot' areas of a local municipal solid waste landfill involved in this study. Based on the available literature, these observations suggest that CH4 can be transported internally by Populus deltoides x Populus nigra seedlings in trace amounts, although future research is required to fully test this hypothesis.

  13. Predation risk, elk, and aspen: tests of a behaviorally mediated trophic cascade in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Winnie, John A

    2012-12-01

    Aspen in the Greater Yellowstone Ecosystem are hypothesized to be recovering from decades of heavy browsing by elk due to a behaviorally mediated trophic cascade (BMTC). Several authors have suggested that wolves interact with certain terrain features, creating places of high predation risk at fine spatial scales, and that elk avoid these places, which creates refugia for plants. This hypothesized BMTC could release aspen from elk browsing pressure, leading to a patchy recovery in places of high risk. I tested whether four specific, hypothesized fine-scale risk factors are correlated with changes in current elk browsing pressure on aspen, or with aspen recruitment since wolf reintroduction, in the Daly Creek drainage in Yellowstone National Park, and near two aspen enclosures outside of the park boundary. Aspen were not responding to hypothesized fine-scale risk factors in ways consistent with the current BMTC hypothesis.

  14. Conservation status of white poplar (Populus alba L. and black poplar (Populus nigra L. in the territory of Great War Island

    Directory of Open Access Journals (Sweden)

    Šijačić-Nikolić Mirjana

    2014-01-01

    Full Text Available T he paper describes t he conservation status of white poplar (Populus alba L. and black poplar (Populus nigra L. in the territory of Great War Island. The activities of in situ and ex situ gene pool conservation have been defined in order to preserve and expand the populations of the above species, as carriers of complex wetland forest ecosystems.

  15. Diversity of leaf traits related to productivity in 31 Populus deltoides x Populus nigra clones.

    Science.gov (United States)

    Marron, Nicolas; Villar, Marc; Dreyer, Erwin; Delay, Didier; Boudouresque, Eric; Petit, Jean-Michel; Delmotte, Francis M; Guehl, Jean-Marc; Brignolas, Franck

    2005-04-01

    To test if some leaf parameters are predictors of productivity in a range of Populus deltoides (Bartr.) Marsh. x P. nigra L. clones, we assessed leaf traits and productivity in 2-month-old rooted cuttings from 31 clones growing in 4-l pots in a greenhouse, under conditions of controlled temperature and optimal irrigation. We evaluated four groups of variables describing (1) productivity (total biomass), (2) leaf growth (total leaf number increment and total leaf area increment rate), (3) leaf structure (specific leaf area and nitrogen and carbon contents) and (4) carbon isotope discrimination (delta), which is negatively correlated with time-integrated water-use efficiency. High-yielding clones did not necessarily display high leaf growth rates, but they displayed a larger total leaf area, lower specific leaf area and lower leaf nitrogen concentration than clones with low productivity. Total leaf area was mainly controlled by maximal individual leaf area and total leaf area increment rate (r = 0.51 and 0.56, respectively). Carbon isotope discrimination did not correlate with total biomass, but it was associated with total number of leaves and total leaf area increment rate (r = 0.39 and 0.45, respectively). Therefore, leaf area and specific leaf area were better indicators of productivity than leaf growth traits. The observed independence of delta from biomass production provides opportunities for selecting poplar clones combining high productivity and high water-use efficiency.

  16. Impact of epidermal leaf mining by the aspen leaf miner (Phyllocnistis populiella) on the growth, physiology, and leaf longevity of quaking aspen

    Science.gov (United States)

    Diane Wagner; Linda DeFoliart; Patricia Doak; Jenny Schneiderheinze

    2008-01-01

    We studied the effect of epidermal mining on aspen growth and physiology during an outbreak of Phyllocnistis populiella in the boreal forest of interior Alaska. Experimental reduction of leaf miner density across two sites and 3 years significantly increased annual apsen growth rates relative to naturally mined controls. Leaf mining damage was...

  17. Increasing the productivity of short-rotation Populus plantations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    DeBell, D.S.; Harrington, C.A.; Clendenen, G.W.; Radwan, M.A.; Zasada, J.C. [Forest Service, Olympia, WA (United States). Pacific Northwest Research Station

    1997-12-31

    This final report represents the culmination of eight years of biological research devoted to increasing the productivity of short rotation plantations of Populus trichocarpa and Populus hybrids in the Pacific Northwest. Studies provide an understanding of tree growth, stand development and biomass yield at various spacings, and how patterns differ by Populus clone in monoclonal and polyclonal plantings. Also included is some information about factors related to wind damage in Populus plantings, use of leaf size as a predictor of growth potential, and approaches for estimating tree and stand biomass and biomass growth. Seven research papers are included which provide detailed methods, results, and interpretations on these topics.

  18. PtaRHE1, a Populus tremula × Populus alba RING‐H2 protein of the ATL family, has a regulatory role in secondary phloem fibre development

    National Research Council Canada - National Science Library

    Baldacci‐Cresp, Fabien; Moussawi, Jihad; Leplé, Jean‐Charles; Van Acker, Rebecca; Kohler, Annegret; Candiracci, Julie; Twyffels, Laure; Spokevicius, Antanas V; Bossinger, Gerd; Laurans, Françoise; Brunel, Nicole; Vermeersch, Marjorie; Boerjan, Wout; El Jaziri, Mondher; Baucher, Marie

    2015-01-01

    .... Previously, we have shown that the expression of Pta RHE 1 , encoding a Populus tremula  ×  Populus alba RING ‐H2 protein with E3 ubiquitin ligase activity, is associated with tissues undergoing secondary growth...

  19. Aspen Simulation of Diesel-Biodiesel Blends Combustion

    Directory of Open Access Journals (Sweden)

    Pérez-Sánchez Armando

    2015-01-01

    Full Text Available Biodiesel is a fuel produced by transesterification of vegetable oils or animal fats, which currently is gaining attention as a diesel substitute. It represents an opportunity to reduce CO2, SO2, CO, HC, PAH and PM emissions and contributes to the diversification of fuels in Mexico's energetic matrix. The results of the simulation of the combustion process are presented in this paper with reference to an engine specification KUBOTA D600-B, operated with diesel-biodiesel blends. The physicochemical properties of the compounds and the operating conditions of equipment were developed using the simulator Aspen® and supplementary information. The main aspects of the engine working conditions were considered such as diesel-biodiesel ratio, air/fuel mixture, temperature of the combustion gases and heat load. Diesel physicochemical specifications were taken from reports of PEMEX and SENER. Methyl esters corresponding to the transesterification of fatty acids that comprise castor oil were regarded as representative molecules of biodiesel obtained from chromatographic analysis. The results include CO2, water vapor, combustion efficiency, power and lower calorific value of fuels.

  20. Characterization of MORE AXILLARY GROWTH Genes in Populus

    Science.gov (United States)

    Czarnecki, Olaf; Yang, Jun; Wang, Xiaoping; Wang, Shucai; Muchero, Wellington; Tuskan, Gerald A.; Chen, Jin-Gui

    2014-01-01

    Background Strigolactones are a new class of plant hormones that play a key role in regulating shoot branching. Studies of branching mutants in Arabidopsis, pea, rice and petunia have identified several key genes involved in strigolactone biosynthesis or signaling pathway. In the model plant Arabidopsis, MORE AXILLARY GROWTH1 (MAX1), MAX2, MAX3 and MAX4 are four founding members of strigolactone pathway genes. However, little is known about the strigolactone pathway genes in the woody perennial plants. Methodology/Principal Finding Here we report the identification of MAX homologues in the woody model plant Populus trichocarpa. We identified the sequence homologues for each MAX protein in P. trichocarpa. Gene expression analysis revealed that Populus MAX paralogous genes are differentially expressed across various tissues and organs. Furthermore, we showed that Populus MAX genes could complement or partially complement the shoot branching phenotypes of the corresponding Arabidopsis max mutants. Conclusion/Significance This study provides genetic evidence that strigolactone pathway genes are likely conserved in the woody perennial plants and lays a foundation for further characterization of strigolactone pathway and its functions in the woody perennial plants. PMID:25036388

  1. Stomatal uptake of O{sub 3} in aspen and aspen-birch forests under free-air CO{sub 2} and O{sub 3} enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Uddling, Johan, E-mail: johan.uddling@dpes.gu.s [Department of Plant and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Goeteborg (Sweden); Hogg, Alan J. [Sweetland Writing Center, University of Michigan, 434 S. State St., Ann Arbor, MI 48109 (United States); Department of Atmospheric, Oceanic, and Space Sciences, 2455 Hayward, University of Michigan, Ann Arbor, MI 48109 (United States); Teclaw, Ronald M. [USDA Forest Service, Northern Research Station, Institute for Applied Ecosystem Studies, Rhinelander, WI 54501 (United States); Carroll, Mary Anne [Department of Atmospheric, Oceanic, and Space Sciences, 2455 Hayward, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Chemistry, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Ellsworth, David S. [Centre for Plant and Food Science, University of Western Sydney, Locked Bag 1797, Penrith South DC NSW 1797 (Australia)

    2010-06-15

    Rising atmospheric carbon dioxide (CO{sub 2}) may alleviate the toxicological impacts of concurrently rising tropospheric ozone (O{sub 3}) during the present century if higher CO{sub 2} is accompanied by lower stomatal conductance (g{sub s}), as assumed by many models. We investigated how elevated concentrations of CO{sub 2} and O{sub 3}, alone and in combination, affected the accumulated stomatal flux of O{sub 3} (AFst) by canopies and sun leaves in closed aspen and aspen-birch forests in the free-air CO{sub 2}-O{sub 3} enrichment experiment near Rhinelander, Wisconsin. Stomatal conductance for O{sub 3} was derived from sap flux data and AFst was estimated either neglecting or accounting for the potential influence of non-stomatal leaf surface O{sub 3} deposition. Leaf-level AFst (AFst{sub l}) was not reduced by elevated CO{sub 2}. Instead, there was a significant CO{sub 2} x O{sub 3} interaction on AFst{sub l}, as a consequence of lower values of g{sub s} in control plots and the combination treatment than in the two single-gas treatments. In addition, aspen leaves had higher AFst{sub l} than birch leaves, and estimates of AFst{sub l} were not very sensitive to non-stomatal leaf surface O{sub 3} deposition. Our results suggest that model projections of large CO{sub 2}-induced reductions in g{sub s} alleviating the adverse effect of rising tropospheric O{sub 3} may not be reasonable for northern hardwood forests. - Stomatal ozone flux in aspen and aspen-birch forests was not reduced by elevated CO{sub 2} concentration.

  2. Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site [Abstract

    Science.gov (United States)

    R. Minocha; S. Long; S. Minocha; P Marquardt; M. Kubiske

    2010-01-01

    The objective of the present study was to evaluate the long-term (10 years) effects of elevated CO2 and O3 on the carbon and nitrogen metabolism of aspen trees. The study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA).

  3. Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Jasiunas, Lukas; Casamassima, Luca

    2015-01-01

    Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co-processing ......Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co......-processing aspen wood and neat glycerol led to a significant reduction in the char yield, and glycerol is hypothesized to act as a radical scavenger, alleviating re-polymerization of especially lignin-derived fragments. In the temperature range of 380–420 °C, it was found that biocrude and char yield, and biocrude...... quality were all invariant to the reaction temperature. By increasing the crude glycerol to aspen wood mass ratio from 0:1 to 3:1, char yield was decreased from 18.3% (only aspen wood) to 3.4%. Furthermore, the biocrude quality in terms of the effective hydrogen-to-carbon ratio (H/Ceff) was significantly...

  4. Functional Characterization and Subcellular Localization of Poplar (Populus trichocarpa × Populus deltoides) Cinnamate 4-Hydroxylase1

    Science.gov (United States)

    Ro, Dae Kyun; Mah, Nancy; Ellis, Brian E.; Douglas, Carl J.

    2001-01-01

    Cinnamic acid 4-hydroxylase (C4H), a member of the cytochrome P450 monooxygenase superfamily, plays a central role in phenylpropanoid metabolism and lignin biosynthesis and possibly anchors a phenylpropanoid enzyme complex to the endoplasmic reticulum (ER). A full-length cDNA encoding C4H was isolated from a hybrid poplar (Populus trichocarpa × P. deltoides) young leaf cDNA library. RNA-blot analysis detected C4H transcripts in all organs tested, but the gene was most highly expressed in developing xylem. C4H expression was also strongly induced by elicitor-treatment in poplar cell cultures. To verify the catalytic activity of the putative C4H cDNA, two constructs, C4H and C4H fused to the FLAG epitope (C4H::FLAG), were expressed in yeast. Immunoblot analysis showed that C4H was present in the microsomal fraction and microsomal preparations from strains expressing both enzymes efficiently converted cinnamic acid to p-coumaric acid with high specific activities. To investigate the subcellular localization of C4H in vivo, a chimeric C4H-green fluorescent protein (GFP) gene was engineered and stably expressed in Arabidopsis. Confocal laser microscopy analysis clearly showed that in Arabidopsis the C4H::GFP chimeric enzyme was localized to the ER. When expressed in yeast, the C4H::GFP fusion enzyme was also active but displayed significantly lower specific activity than either C4H or C4H::FLAG in in vitro and in vivo enzyme assays. These data definitively show that C4H is localized to the ER in planta. PMID:11351095

  5. Impact of drought on productivity and water use efficiency in 29 genotypes of Populus deltoides x Populus nigra.

    Science.gov (United States)

    Monclus, Romain; Dreyer, Erwin; Villar, Marc; Delmotte, Francis M; Delay, Didier; Petit, Jean-Michel; Barbaroux, Cécile; Le Thiec, Didier; Bréchet, Claude; Brignolas, Franck

    2006-01-01

    We examined the relationships among productivity, water use efficiency (WUE) and drought tolerance in 29 genotypes of Populus x euramericana (Populus deltoides x Populus nigra), and investigated whether some leaf traits could be used as predictors for productivity, WUE and drought tolerance. At Orléans, France, drought was induced on one field plot by withholding water, while a second plot remained irrigated and was used as a control. Recorded variables included stem traits (e.g. biomass) and leaf structural (e.g. leaf area) and functional traits [e.g. intrinsic water use efficiency (Wi) and carbon isotope discrimination (Delta)]. Productivity and Delta displayed large genotypic variability and were not correlated. Delta scaled negatively with Wi and positively with stomatal conductance under moderate drought, suggesting that the diversity for Delta was mainly driven by stomatal conductance. Most of the productive genotypes displayed a low level of drought tolerance (i.e. a large reduction of biomass), while the less productive genotypes presented a large range of drought tolerance. The ability to increase WUE in response to water deficit was necessary but not sufficient to explain the genotypic diversity of drought tolerance.

  6. Dense genetic linkage maps of three Populus species (Populus deltoides, P. nigra and P. trichocarpa) based on AFLP and microsatellite markers.

    OpenAIRE

    Cervera, M.t.; Storme, V; Ivens, B; Gusmão, J; Liu, B. H.; Hostyn, V; Van Slycken, J; Van Montagu, M; Boerjan, W.

    2001-01-01

    Populus deltoides, P. nigra, and P. trichocarpa are the most important species for poplar breeding programs worldwide. In addition, Populus has become a model for fundamental research on trees. Linkage maps were constructed for these three species by analyzing progeny of two controlled crosses sharing the same female parent, Populus deltoides cv. S9-2 x P. nigra cv. Ghoy and P. deltoides cv. S9-2 x P. trichocarpa cv. V24. The two-way pseudotestcross mapping strategy was used to construct the ...

  7. Harvesting overmature aspen stands in central Alberta. FERIC special report No. SR-112

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, B.; Evans, C.M.

    1996-12-31

    Describes a project undertaken to examine the performance of feller-bunchers, grapple skidders, roadside delimbers, and slashers operating in overmature aspen stands in central Alberta. The project aimed at providing the forest industry with information for projecting productivities and costs of harvesting overmature aspen stands. The investigators measured machine productivity in aspen stands of different characteristics, as well as fibre losses from excessive butt rot, upper stem defects, and conversion of tree-length stems into 2.6-metre logs. The field data provided input for determining operating cost and projected machine productivity as functions of tree size or skidding distance. The report also discusses the impact on cost of harvesting decaying stands.

  8. Fibrillation of Aspen by Alkaline Cold Pre-treatment and Vibration Milling

    Directory of Open Access Journals (Sweden)

    Kärt KÄRNER

    2016-09-01

    Full Text Available In this article an attempt to fibrillate aspen bleached chemi-thermo mechanical pulp (BCTMP fibre in an environmentally friendly way is reported. The effects of various NaOH, KOH, urea and ethanol aqueous solutions at lowered temperature were tested for pre-treatment. The pre-treatment was followed by vibration milling aiming to peel off outer cell wall layers and to fibrillate S2 layer of the aspen wood fibre. The effects of the treatments were evaluated by scanning electron microscopy (SEM. The results show that it is possible to fibrillate BCTMP aspen fibres by using alkaline aqueous solutions at low temperatures followed by a mechanical treatment. A strong dependence on fibrillation of cellulose on temperature, time and alkali concentration was established.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7412

  9. Genetic and environmental factors affecting early rooting of six Populus genomic groups: implications for tree improvement

    Science.gov (United States)

    Ronald S., Jr. Zalesny

    2006-01-01

    Genetic and environmental factors affect the early rooting of Populus planted as unrooted hardwood cuttings. Populus genotypes of six genomic groups were tested in numerous studies for the quantitative genetics of rooting, along with effects of preplanting treatments and soil temperature. Genetics data (e.g. heritabilities,...

  10. Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) Larval Performance on Eight Populus Clones

    Science.gov (United States)

    David R. Coyle; Joel D. McMillin; Richard B. Hall; Elwood R. Hart

    2001-01-01

    Abstract: The cottonwood leaf beetle, Chrysomela scripta F., is the most serious defoliator of young plantation-grown Populus in the eastern United States, yet there is a paucity of data on larval feeding performance across Populus clones used in tree breeding. Field experiments were conducted in 1998 and 1999...

  11. Multiple factors affect pest and pathogen damage on 31 Populus clones in South Carolina

    Science.gov (United States)

    David R. Coyle; Mark D. Coleman; Jaclin A. Durant; Lee A. Newman

    2006-01-01

    Populus species and hybrids have many practical applications, but there is a paucity of data regarding selections that perform well in the southeastern US. We compared pest susceptibility of 31 Populus clones over 3 years in South Carolina, USA. Cuttings were planted in spring 2001 on two study sites. Clones planted in the...

  12. Leaf, woody, and root biomass of Populus irrigated with landfill leachate

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; D.R. Coyle; R.B. Hall

    2007-01-01

    Poplar (Populus spp.) trees can be utilized for ecological leachate disposal when applied as an irrigation source for managed tree systems. Our objective was to evaluate differences in tree height, diameter, volume, and biomass of leaf, stem, branch, and root tissues of Populus trees after two seasons of irrigation with municipal...

  13. Modeling Carbon Dioxide Capture by Monoethanolamine Solvent with ASPEN Plus

    Science.gov (United States)

    Luo, Tianyi

    Fossil fuels provide approximately 80% of the world's energy demands. Methods for reducing CO2 emissions resulting from fossil fuels include increasing the efficiency of power plants and production processes, decreasing energy demands, in combination with CO2 capture and long term storage (CCS). CO2 capture technologies include post-combustion, pre-combustion, and oxyfuel combustion. The amine-based post-combustion CO2 capture from a coal-fired power plant was studied in this thesis. In case of post-combustion capture, CO2 can be captured by Monoethanolamine solvent (MEA), a primary ethanolamine. MEA can associate with H3O+ to form an ion MEAH+, and can react with CO2 to form a carbonate ion MEACOO-. Commercial code ASPEN Plus was used to simulate the process of CO2 capture and optimize the process parameters and required energy duty. The major part of thermal energy requirement is from the Absorber and Stripper columns. This suggests that process optimization should focus on the Absorption/Desorption process. Optimization results show that the gas-liquid reaction equilibrium is affected by several operating parameters including solvent flow rate, stream temperature, column operating pressure, flue gas composition, solvent concentration and absorber design. With optimized CO2 capture, the energy consumption for solvent regeneration (reboiler thermal duty) was decreased from 5.76 GJ/ton captured CO2 to 4.56 GJ/t CO2. On the other hand, the cost of CO2 capture (and sequestration) could be reduced by limiting size of the Absorber column and operating pressure.

  14. Conifer expansion reduces the competitive ability and herbivore defense of aspen by modifying light environment and soil chemistry.

    Science.gov (United States)

    Calder, W John; Horn, Kevin J; St Clair, Samuel B

    2011-06-01

    Disturbance patterns strongly influence plant community structure. What remains less clear, particularly at a mechanistic level, is how changes in disturbance cycles alter successional outcomes in plant communities. There is evidence that fire suppression is resulting in longer fire return intervals in subalpine forests and that these lengthened intervals increase competitive interactions between aspen and conifer species. We conducted a field and greenhouse study to compare photosynthesis, growth and defense responses of quaking aspen and subalpine fir regeneration under light reductions and shifts in soil chemistry that occur as conifers increase in dominance. The studies demonstrated that aspen regeneration was substantially more sensitive to light and soil resource limitations than that of subalpine fir. For aspen, light reductions and/or shifts in soil chemistry limited height growth, biomass gain, photosynthesis and the production of defense compounds (phenolic glycosides and condensed tannins). Biomass gain and phenolic glycoside concentrations were co-limited by light reduction and changes in soil chemistry. In contrast, subalpine fir seedlings tended to be more tolerant of low light conditions and showed no sensitivity to changes in soil chemistry. Unlike aspen, subalpine fir increased its root to shoot ratio on conifer soils, which may partially explain its maintenance of growth and defense. The results suggest that increasing dominance of conifers in subalpine forests alters light conditions and soil chemistry in a way that places greater physiological and growth constraints on aspen than subalpine fir, with a likely outcome being more successful recruitment of conifers and losses in aspen cover.

  15. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    Directory of Open Access Journals (Sweden)

    Javier Fontalvo Alzate

    2014-05-01

    Full Text Available Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed description of how to implement this integration. The interface between Matlab and Aspen Plus is accomplished by sending the relevant information from Aspen Plus to Excel, which feeds the information to a Matlab routine. Once the Matlab routine processes the information, it is returned to Excel and to Aspen Plus. This paper includes the Excel and Matlab template files so the reader can implement their own simulations. By applying the protocol described here, a hybrid distillation-vapor permeation system has been simulated as an example of the applications that can be implemented. For the hybrid system, the effect of membrane selectivity on membrane area and reboiler duty for the partial dehydration of ethanol is studied. Very high selectivities are not necessarily required for an optimum hybrid distillation and vapor permeation system.

  16. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    Directory of Open Access Journals (Sweden)

    Javier Fontalvo Alzate

    2014-07-01

    Full Text Available Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed description of how to implement this integration. The interface between Matlab and Aspen Plus is accomplished by sending the relevant information from Aspen Plus to Excel, which feeds the information to a Matlab routine. Once the Matlab routine processes the information, it is returned to Excel and to Aspen Plus. This paper includes the Excel and Matlab template files so the reader can implement their own simulations. By applying the protocol described here, a hybrid distillation-vapor permeation system has been simulated as an example of the applications that can be implemented. For the hybrid system, the effect of membrane selectivity on membrane area and reboiler duty for the partial dehydration of ethanol is studied. Very high selectivities are not necessarily required for an optimum hybrid distillation and vapor permeation system.

  17. ASPEN Plus in the Chemical Engineering Curriculum: Suitable Course Content and Teaching Methodology

    Science.gov (United States)

    Rockstraw, David A.

    2005-01-01

    An established methodology involving the sequential presentation of five skills on ASPEN Plus to undergraduate seniors majoring in ChE is presented in this document: (1) specifying unit operations; (2) manipulating physical properties; (3) accessing variables; (4) specifying nonstandard components; and (5) applying advanced features. This…

  18. ASPEN+ and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis

    Science.gov (United States)

    ASPEN Plus based simulation models have been developed to design a pyrolysis process for the on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all available Equine Reh...

  19. The extent and characteristics of low-productivity aspen areas in Wisconsin.

    Science.gov (United States)

    Allen L. Lundgren; Jerold T. Hahn

    1978-01-01

    An analysis of inventory plots from Wisconsin's forest survey showed that 18% of the state's 3.7 million acres of aspen type was producing less than a quarter of potential volume yields and 47% was producing less than half of potential volume yields.

  20. 78 FR 46312 - Spruce Beetle Epidemic and Aspen Decline Management Response; Grand Mesa, Uncompahgre and...

    Science.gov (United States)

    2013-07-31

    ... Colorado Plateau. It covers 3,161,900 acres across diverse vegetation ranging from sagebrush, pi on... may be used in high value areas. Aspen stands where less than 50% of the root system has been affected... Roadless Areas (CRAs), Research Natural Areas or Special Management Areas managed for Wilderness values...

  1. Sudden aspen decline in southwest Colorado: Site and stand factors and a hypothesis on etiology

    Science.gov (United States)

    Jim Worrall; Leanne Egeland; Tom Eager; Roy Mask; Erik Johnson; Phil Kemp; Wayne Shepperd

    2008-01-01

    An initial assessment of rapid dieback and mortality of aspen in southwest Colorado suggests that it represents a decline disease incited by acute, warm drought. Predisposing factors include low elevation, south and southwest aspects, droughty soils, open stands, and physiological maturity. Contributing factors include Cytospora canker, two bark beetles, poplar borer,...

  2. Phosphate removal by refined aspen wood fiber treated with carboxymethyl cellulose and ferrous chloride

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min; James S. Han

    2006-01-01

    Biomass-based filtration media are of interest as an economical means to remove pollutants and nutrients found in stormwater runoff. Refined aspen wood fiber samples treated with iron salt solutions demonstrated limited capacities to remove (ortho)phosphate from test solutions. To provide additional sites for iron complex formation, and thereby impart a greater...

  3. Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.

    Science.gov (United States)

    Koeduka, Takao; Suzuki, Shiro; Iijima, Yoko; Ohnishi, Toshiyuki; Suzuki, Hideyuki; Watanabe, Bunta; Shibata, Daisuke; Umezawa, Toshiaki; Pichersky, Eran; Hiratake, Jun

    2013-06-21

    Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eugenol levels and up to 22-fold eugenol glycoside levels in leaves of transgenic aspen plants. The overexpression of PhEGS alone resulted in a subtle increase in either eugenol or eugenol glycosides, and the overexpression of both PhCFAT and PhEGS resulted in significant increases in the levels of both eugenol and eugenol glycosides which were nonetheless lower than the increases seen with overexpression of PhCFAT alone. On the other hand, overexpression of PhCFAT in transgenic Arabidopsis and tobacco did not cause any synthesis of eugenol. These results indicate that aspen leaves, but not Arabidopsis and tobacco leaves, have a partially active pathway to eugenol that is limited by the level of CFAT activity and thus the flux of this pathway can be increased by the introduction of a single heterologous gene. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Using Aspen to Teach Chromatographic Bioprocessing: A Case Study in Weak Partitioning Chromatography for Biotechnology Applications

    Science.gov (United States)

    Evans, Steven T.; Huang, Xinqun; Cramer, Steven M.

    2010-01-01

    The commercial simulator Aspen Chromatography was employed to study and optimize an important new industrial separation process, weak partitioning chromatography. This case study on antibody purification was implemented in a chromatographic separations course. Parametric simulations were performed to investigate the effect of operating parameters…

  5. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  6. 75 FR 13805 - Aspen Group Resources Corp., Commercial Concepts, Inc., Desert Health Products, Inc., Equalnet...

    Science.gov (United States)

    2010-03-23

    ... COMMISSION Aspen Group Resources Corp., Commercial Concepts, Inc., Desert Health Products, Inc., Equalnet Communications Corp., Geneva Steel Holdings Corp., Orderpro Logistics, Inc. (n/k/a Securus Renewable Energy, Inc... accurate information concerning the securities of Commercial Concepts, Inc. because it has not filed any...

  7. Aspen development on similar soils in Minnesota and British Columbia after compaction and forest floor removal

    Science.gov (United States)

    Douglas M. Stone; Richard Kabzems

    2002-01-01

    Forest management practices that decrease soil porosity and remove organic matter can reduce site productivity. We evaluated effects of four treatments-merchantable bole harvest (MBH) with three levels of soil compaction (none, light, or heavy), and total woody vegetation harvest plus forest floor removal (FFR)-on fifth-year regeneration and growth of aspen (...

  8. Relationships between Soil compaction and harvest season, soil texture, and landscape position for aspen forests

    Science.gov (United States)

    Randy Kolka; Aaron Steber; Ken Brooks; Charles H. Perry; Matt. Powers

    2012-01-01

    Although a number of harvesting studies have assessed compaction, no study has considered the interacting relationships of harvest season, soil texture, and landscape position on soil bulk density and surface soil strength for harvests in the western Lake States. In 2005, we measured bulk density and surface soil strength in recent clearcuts of predominantly aspen...

  9. Surface compaction estimates and soil sensitivity in Aspen stands of the Great Lakes States

    Science.gov (United States)

    Aaron Steber; Ken Brooks; Charles H. Perry; Randy Kolka

    2007-01-01

    Aspen forests in the Great Lakes States support much of the regional timber industry. Management-induced soil compaction is a concern because it affects forest health and productivity and soil erosion. Soil compaction increases bulk density and soil strength and can also decrease air and water movement into and through the soil profile. Currently, most inventories, and...

  10. 77 FR 60373 - Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and Piute...

    Science.gov (United States)

    2012-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Forest Service Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and... Open House will be held at the Sevier County Administrative Building in Richfield, Utah October 10, 6...

  11. Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

    Science.gov (United States)

    Edward L. Springer; John F. Harris

    1982-01-01

    Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

  12. Snow ablation modelling in a mature aspen stand of the boreal forest

    Science.gov (United States)

    Hardy, J. P.; Davis, R. E.; Jordan, R.; Ni, W.; Woodcock, C. E.

    1998-07-01

    Snow ablation modelling at the stand scale must account for the variability in snow cover and the large variations of components of energy transfer at the forest floor. Our previous work successfully predicted snow ablation in a mature jack pine stand by using a one-dimensional snow process model and models predicting radiation below forest canopies. This work represents a second test of our basic modelling scenario by predicting snow ablation in a leafless, deciduous aspen stand and verifying the results with field data. New modifications to the snow model accounted for decreased albedo owing to radiation penetration through optically thin snowpacks. A provisional equation estimates litter fall on the snowpack, thereby reducing the areal averaged albedo. We showed that subcanopy radiation measurements can be used with a canopy model to estimate a branch area index for defoliated aspen as an analogue to the foliage area index used for conifers. Modelled incoming solar and long-wave radiation showed a strong correlation with measurements, with r2=0·96 and 0·91 for solar and long-wave radiation, respectively. Model results demonstrate that net radiation overwhelms turbulent exchanges as the most significant driving force for snowmelt in aspen forests. Predicted snow ablation in the aspen stand compared very favourably with available data on snow depth.

  13. Initial characterization of shade avoidance response suggests functional diversity between Populus phytochrome B genes.

    Energy Technology Data Exchange (ETDEWEB)

    Karve, Abhijit A [ORNL; Weston, David [ORNL; Jawdy, Sara [ORNL; Gunter, Lee E [ORNL; Allen, Sara M [ORNL; Yang, Xiaohan [ORNL; Wullschleger, Stan D [ORNL; Tuskan, Gerald A [ORNL

    2012-01-01

    Shade avoidance signaling in higher plants involves perception of the incident red/far-red (R/FR) light by phytochromes and the modulation of downstream transcriptional networks to regulate developmental plasticity in relation to heterogeneous light environments. In this study, we characterized the expression and functional features of Populus phytochrome (PHY) gene family as well as the transcriptional responses of Populus to the changes in R/FR light. Expression data indicated that PHYA is the predominant PHY in the dark grown Populus seedling whereas PHYBs are most abundant in mature tissue types. Out of three Populus PHYs, PHYA is light labile and localized to cytosol in dark whereas both PHYB1 and PHYB2 are light stable and are localized to nucleus in mesophyll protoplasts. When expressed in Arabidopsis, PHYB1 rescued Arabidopsis phyB mutant phenotype whereas PHYB2 did not, suggesting functional diversification between these two gene family members. However, phenotypes of transgenic Populus lines with altered expression of PHYB1, PHYB2 or both and the expression of candidate shade response genes in these transgenic lines suggest that PHYB1 and PHYB2 may have distinct yet overlapping functions. The RNAseq results and analysis of Populus exposed to enriched-FR light indicate that genes associated in cell wall modification and brassinosteroid signaling were induced under far red light. Overall our data indicate that Populus transcriptional responses are at least partially conserved with Arabidopsis.

  14. Initial characterization of shade avoidance response suggests functional diversity between Populus phytochrome B genes.

    Science.gov (United States)

    Karve, Abhijit A; Jawdy, Sara S; Gunter, Lee E; Allen, Sara M; Yang, Xiaohan; Tuskan, Gerald A; Wullschleger, Stan D; Weston, David J

    2012-11-01

    Shade avoidance signaling involves perception of incident red/far-red (R/FR) light by phytochromes (PHYs) and modulation of downstream transcriptional networks. Although these responses are well studied in Arabidopsis, little is known about the role of PHYs and the transcriptional responses to shade in the woody perennial Populus. Tissue expression and subcellular localization of Populus PHYs was studied by quantitative real-time PCR (qRT-PCR) and protoplast transient assay. Transgenic lines with altered PHYB1 and/or PHYB2 expression were used in phenotypic assays and transcript profiling with qRT-PCR. RNA-Seq was used to identify transcriptional responses to enriched FR light. All three PHYs were differentially expressed among tissue types and PHYBs were targeted to the nucleus under white light. Populus PHYB1 rescued Arabidopsis phyB mutant phenotypes. Phenotypes of Populus transgenic lines and the expression of candidate shade response genes suggested that PHYB1 and PHYB2 have distinct yet overlapping functions. RNA-Seq analysis indicated that genes associated with cell wall modification and brassinosteroid signaling were induced under enriched FR light in Populus. This study is an initial attempt at deciphering the role of Populus PHYs by evaluating transcriptional reprogramming to enriched FR and demonstrates functional diversity and overlap of the Populus PHYB1 and PHYB2 in regulating shade responses. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  15. Intraspecific and interspecific genetic and phylogenetic relationships in the genus Populus based on AFLP markers.

    Science.gov (United States)

    Cervera, M T; Storme, V; Soto, A; Ivens, B; Van Montagu, M; Rajora, O P; Boerjan, W

    2005-11-01

    Although Populus has become the model genus for molecular genetics and genomics research on forest trees, genetic and phylogenetic relationships within this genus have not yet been comprehensively studied at the molecular level. By using 151 AFLP (AFLP is a registered trademark of Keygene) markers, 178 accessions belonging to 25 poplar species and three interspecific hybrids were analyzed, using three accessions belonging to two willow species as outgroups. The genetic and phylogenetic relationships were generally consistent with the known taxonomy, although notable exceptions were observed. A dendrogram as well as a single most parsimonious tree, ordered the Populus sections from the oldest Leuce to the latest Aigeiros, a pattern consistent with their known evolutionary relationships. A close relationship between Populus deltoides of the Aigeiros section and species of the Tacamahaca section was observed and, with the exception of Populus wilsonii, between the species of the Leucoides, Tacamahaca, and Aigeiros sections. Populus nigra was clearly separated from its consectional P. deltoides, and should be classified separately from P. deltoides. The AFLP profiles pointed out to the lack of divergence between some species and revealed that some accessions corresponded with interspecific hybrids. This molecular study provides useful information about genetic relationships among several Populus species and, together with morphological descriptions and crossability, it may help review and update systematic classification within the Populus genus.

  16. Functional annotation of 19,841 Populus nigra full-length enriched cDNA clones

    Science.gov (United States)

    Nanjo, Tokihiko; Sakurai, Tetsuya; Totoki, Yasushi; Toyoda, Atsushi; Nishiguchi, Mitsuru; Kado, Tomoyuki; Igasaki, Tomohiro; Futamura, Norihiro; Seki, Motoaki; Sakaki, Yoshiyuki; Shinozaki, Kazuo; Shinohara, Kenji

    2007-01-01

    Background Populus is one of favorable model plants because of its small genome. Structural genomics of Populus has reached a breakpoint as nucleotides of the entire genome have been determined. Reaching the post genome era, functional genomics of Populus is getting more important for well-comprehended plant science. Development of bioresorce serving functional genomics is making rapid progress. Huge efforts have achieved deposits of expressed sequence tags (ESTs) in various plant species consequently accelerating functional analysis of genes. ESTs from full-length cDNA clones are especially powerful for accurate molecular annotation. We promoted collection and annotation of the ESTs from Populus full-length enriched cDNA clones as part of functional genomics of tree species. Results We have been collecting the full-length enriched cDNA of the female poplar (Populus nigra var. italica) for years. By sequencing P. nigra full-length (PnFL) cDNA libraries, we generated about 116,000 5'-end or 3'-end ESTs corresponding to 19,841 nonredundant PnFL clones. Population of PnFL cDNA clones represents 44% of the predicted genes in the Populus genome. Conclusion Our resource of P. nigra full-length enriched clones is expected to provide valuable tools to gain further insight into genome annotation and functional genomics in Populus. PMID:18053163

  17. Functional annotation of 19,841 Populus nigra full-length enriched cDNA clones

    Directory of Open Access Journals (Sweden)

    Seki Motoaki

    2007-12-01

    Full Text Available Abstract Background Populus is one of favorable model plants because of its small genome. Structural genomics of Populus has reached a breakpoint as nucleotides of the entire genome have been determined. Reaching the post genome era, functional genomics of Populus is getting more important for well-comprehended plant science. Development of bioresorce serving functional genomics is making rapid progress. Huge efforts have achieved deposits of expressed sequence tags (ESTs in various plant species consequently accelerating functional analysis of genes. ESTs from full-length cDNA clones are especially powerful for accurate molecular annotation. We promoted collection and annotation of the ESTs from Populus full-length enriched cDNA clones as part of functional genomics of tree species. Results We have been collecting the full-length enriched cDNA of the female poplar (Populus nigra var. italica for years. By sequencing P. nigra full-length (PnFL cDNA libraries, we generated about 116,000 5'-end or 3'-end ESTs corresponding to 19,841 nonredundant PnFL clones. Population of PnFL cDNA clones represents 44% of the predicted genes in the Populus genome. Conclusion Our resource of P. nigra full-length enriched clones is expected to provide valuable tools to gain further insight into genome annotation and functional genomics in Populus.

  18. Antioxidant polyphenols from Populus alba growing in Georgia.

    Science.gov (United States)

    Kuchukhidze, J; Jokhadze, M; Murtazashvili, T; Mshvildadze, V

    2011-10-01

    The aim of the study was to evaluate natural antioxidant properties of Populus alba. The antioxidant effects in plants are mainly due to the presence of phenolic compounds such as flavonoids, phenolic acids, tannins and phenolic diterpenes. Oxidative damage is implicated in most diseases processes. In vitro studies are able to demonstrate for flavonols and flavones a considerable antioxidative activity, mainly based on scavenging of oxygen radicals. The antioxidative potential of different fractions (respective organic fractions of n-hexane, chloroform and ethyl acetate) of 70% methanol extract of Populus alba was evaluated using free radical-scavenging activity on DPPH (1,1-diphenyl-2-picrylhydrazyl ) assays. The methanol extract showed significant (p<0.05) activities in all antioxidant assays and contained a high level of total phenolic content. It was observed that the level of hydrophilic phenolic content was higher than that of hydrophobics. Among those organic solvent fractions, ethyl acetate fraction exhibited significant activities due to the highest level of total phenolic content and their IC50 values were 0.18±0.02 mg/mL, 0.26±0.03mg/mL and 0.28±0.02 mg/mL in DPPH, respectively. These activities were superior to those of a commercial natural antioxidants tested. The chloroform and hexan fractions also exhibited significant (p<0.05) free radical-scavenging activity, attributed to the high amount of hydrophilic phenolics.

  19. Survival and growth of 31 Populus clones in South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, David R.; Coleman, Mark D. [USDA Forest Service, Southern Research Station, P.O. Box 700, New Ellenton, SC 29809 (United States); Durant, Jaclin A.; Newman, Lee A. [Arnold School of Public Health, Department of Environmental Health Sciences, University of South Carolina, 800 Sumter Street, Columbia, SC 29208 (United States)

    2006-08-15

    Populus species and hybrids have many practical applications, but clonal performance is relatively undocumented in the southeastern United States outside of the Mississippi River alluvial floodplain. In spring 2001, 31 Populus clones were planted on two sites in South Carolina, USA. The sandy, upland site received irrigation and fertilization throughout the growing season, while the bottomland site received granular fertilizer yearly and irrigation in the first two years only. Over three growing seasons, tree survival and growth differed significantly among clones at both sites. Hybrid clones I45/51, Eridano, and NM6 had very high survival at both sites, while pure eastern cottonwood (P. deltoides) clones consistently had the lowest survival. Nearly all mortality occurred during the first year. The P. deltoides clone WV416 grew well at both sites, P. deltoides clones S13C20 and Kentucky 8 grew well at the bottomland site, and hybrids 184-411 and 52-225 grew well at the upland site. Based on both survival and growth, clones 311-93, S7C15, 184-411, and WV416 may warrant additional testing in the upper coastal plain region of the southeastern US. Kentucky 8 and S13C20 had excellent growth rates, but initial survival was low. However, this was likely due to planting stock quality. We emphasize this is preliminary information, and that clones should be followed through an entire rotation before large-scale deployment. (author)

  20. Comprehensive analysis of CCCH zinc finger family in poplar (Populus trichocarpa)

    Science.gov (United States)

    2012-01-01

    Background CCCH zinc finger proteins contain a typical motif of three cysteines and one histidine residues and serve regulatory functions at all stages of mRNA metabolism. In plants, CCCH type zinc finger proteins comprise a large gene family represented by 68 members in Arabidopsis and 67 in rice. These CCCH proteins have been shown to play diverse roles in plant developmental processes and environmental responses. However, this family has not been studied in the model tree species Populus to date. Results In the present study, a comprehensive analysis of the genes encoding CCCH zinc finger family in Populus was performed. Using a thorough annotation approach, a total of 91 full-length CCCH genes were identified in Populus, of which most contained more than one CCCH motif and a type of non-conventional C-X11-C-X6-C-X3-H motif was unique for Populus. All of the Populus CCCH genes were phylogeneticly clustered into 13 distinct subfamilies. In each subfamily, the gene structure and motif composition were relatively conserved. Chromosomal localization of these genes revealed that most of the CCCHs (81 of 90, 90 %) are physically distributed on the duplicated blocks. Thirty-four paralogous pairs were identified in Populus, of which 22 pairs (64.7 %) might be created by the whole genome segment duplication, whereas 4 pairs seem to be resulted from tandem duplications. In 91 CCCH proteins, we also identified 63 putative nucleon-cytoplasm shuttling proteins and 3 typical RNA-binding proteins. The expression profiles of all Populus CCCH genes have been digitally analyzed in six tissues across different developmental stages, and under various drought stress conditions. A variety of expression patterns of CCCH genes were observed during Populus development, of which 34 genes highly express in root and 22 genes show the highest level of transcript abundance in differentiating xylem. Quantitative real-time RT-PCR (RT-qPCR) was further performed to confirm the tissue

  1. Hydrogen Peroxide Response in Leaves of Poplar (Populus simonii × Populus nigra Revealed from Physiological and Proteomic Analyses

    Directory of Open Access Journals (Sweden)

    Juanjuan Yu

    2017-10-01

    Full Text Available Hydrogen peroxide (H2O2 is one of the most abundant reactive oxygen species (ROS, which plays dual roles as a toxic byproduct of cell metabolism and a regulatory signal molecule in plant development and stress response. Populus simonii × Populus nigra is an important cultivated forest species with resistance to cold, drought, insect and disease, and also a key model plant for forest genetic engineering. In this study, H2O2 response in P. simonii × P. nigra leaves was investigated using physiological and proteomics approaches. The seedlings of 50-day-old P. simonii × P. nigra under H2O2 stress exhibited stressful phenotypes, such as increase of in vivo H2O2 content, decrease of photosynthetic rate, elevated osmolytes, antioxidant accumulation, as well as increased activities of several ROS scavenging enzymes. Besides, 81 H2O2-responsive proteins were identified in the poplar leaves. The diverse abundant patterns of these proteins highlight the H2O2-responsive pathways in leaves, including 14-3-3 protein and nucleoside diphosphate kinase (NDPK-mediated signaling, modulation of thylakoid membrane structure, enhancement of various ROS scavenging pathways, decrease of photosynthesis, dynamics of proteins conformation, and changes in carbohydrate and other metabolisms. This study provides valuable information for understanding H2O2-responsive mechanisms in leaves of P. simonii × P. nigra.

  2. Performance of Salix viminalis and Populus nigra x Populus maximowiczii in short rotation intensive culture under high irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Fillion, Maud; Brisson, Jacques [Departement de Sciences biologiques, Universite de Montreal, C.P. 6128, succ. Centre-ville, Montreal, Quebec (Canada); Institut de recherche en biologie vegetale, 4101 Sherbrooke East, Montreal, Quebec (Canada); Teodorescu, Traian I.; Labrecque, Michel [Institut de recherche en biologie vegetale, 4101 Sherbrooke East, Montreal, Quebec (Canada); Sauve, Sebastien [Departement de chimie, Universite de Montreal, C.P. 6128, succursale Centre-ville, Montreal, Quebec (Canada)

    2009-09-15

    On a plantation established in 2004 from stem cuttings at a density of 20,000 trees per hectare, we investigated growth and nutritional plant response to a high hydraulic regime for two species (Salix viminalis and Populus nigra x Populus maximowiczii), using a comparative approach with measurements from irrigated and control plots. The plantation was irrigated from June to September 2005 with about 140 mm per day. The equivalent of 120 Kg NO{sub 3}-N, 40 Kg P{sub 2}O{sub 5}-P and 85 Kg K{sub 2}O-K per hectare per year was applied by means of irrigation with wastewater. No mortality occurred and stem biomass production of both poplar and willow species were not statistically different on irrigated and control areas. However, S. viminalis revealed to be more tolerant to flooded conditions since these corresponded more closely to its nutritional requirements (foliar concentration of 20 mgN g{sup -1}). The capacity of S. viminalis to withstand waterlogged conditions could play an important role in the sustainability of a plantation for the filtration of effluent at low pollutant concentration. (author)

  3. How to Create, Modify, and Interface Aspen In-House and User Databanks for System Configuration 2:

    Energy Technology Data Exchange (ETDEWEB)

    Camp, D W

    2000-10-27

    The goal of this document is to provide detailed instructions to create, modify, interface, and test Aspen User and In-House databanks with minimal frustration. The level of instructions are aimed at a novice Aspen Plus simulation user who is neither a programming nor computer-system expert. The instructions are tailored to Version 10.1 of Aspen Plus and the specific computing configuration summarized in the Title of this document and detailed in Section 2. Many details of setting up databanks depend on the computing environment specifics, such as the machines, operating systems, command languages, directory structures, inter-computer communications software, the version of the Aspen Engine and Graphical User Interface (GUI), and the directory structure of how these were installed.

  4. Using low energy x-ray radiography to evaluate root initiation and growth of Populus

    Science.gov (United States)

    Ronald S., Jr. Zalesny; A. L. Friend; B. Kodrzycki; D.W. McDonald; R. Michaels; A.H. Wiese; J.W. Powers

    2007-01-01

    Populus roots have been studied less than aboveground tissues. However, there is an overwhelming need to evaluate root initiation and growth in order to understand the genetics and physiology of rooting, along with genotype x environment interactions.

  5. Gene expression and characterization of isoprene synthase from Populus alba.

    Science.gov (United States)

    Sasaki, Kanako; Ohara, Kazuaki; Yazaki, Kazufumi

    2005-04-25

    Isoprene synthase cDNA from Populus alba (PaIspS) was isolated by RT-PCR. This PaIspS mRNA, which was predominantly observed in the leaves, was strongly induced by heat stress and continuous light irradiation, and was substantially decreased in the dark, suggesting that isoprene emission was regulated at the transcriptional level. The subcellular localization of PaIspS protein with green fluorescent protein fusion was shown to be in plastids. PaIspS expressed in Escherichia coli was characterized enzymatically: it had an optimum pH of approximately 8.0, and an optimum temperature 40 degrees C. Its preference for divalent cations for its activity was also studied.

  6. Transcriptional profiles of the annual growth cycle in Populus deltoides.

    Science.gov (United States)

    Park, Sunchung; Keathley, Daniel E; Han, Kyung-Hwan

    2008-03-01

    Cycling between vegetative growth and dormancy is an important adaptive mechanism in temperate woody plants. To gain insights into the underlying molecular mechanisms, we carried out global transcription analyses on stem samples from poplar (Populus deltoides Bartr. ex Marsh.) trees grown in the field and in controlled environments. Among seasonal changes in the transcriptome, up-regulation of defense-related genes predominated in early winter, whereas signaling-related genes were up-regulated during late winter. Cluster analysis of the differentially expressed genes showed that plants regulated seasonal growth by integrating environmental factors with development. Short day lengths induced some cold-associated genes without concomitant low temperature exposure, and enhanced the expression of some genes when combined with low temperature exposure. These mechanisms appear to maintain closer synchrony between cold hardiness and climate than would be achieved through responses to temperature alone.

  7. The proteome of Populus nigra woody root: response to bending

    Science.gov (United States)

    Trupiano, Dalila; Rocco, Mariapina; Renzone, Giovanni; Scaloni, Andrea; Viscosi, Vincenzo; Chiatante, Donato; Scippa, Gabriella S.

    2012-01-01

    Background and Aims Morphological and biomechanical alterations occurring in woody roots of many plant species in response to mechanical stresses are well documented; however, little is known about the molecular mechanisms regulating these important alterations. The first forest tree genome to be decoded is that of Populus, thereby providing a tool with which to investigate the mechanisms controlling adaptation of woody roots to changing environments. The aim of this study was to use a proteomic approach to investigate the response of Populus nigra woody taproot to mechanical stress. Methods To simulate mechanical perturbations, the taproots of 30 one-year-old seedlings were bent to an angle of 90 ° using a steel net. A spatial and temporal two-dimensional proteome map of the taproot axis was obtained. We compared the events occurring in the above-bending, central bending and below-bending sectors of the taproot. Key Results The first poplar woody taproot proteome map is reported here; a total of 207 proteins were identified. Spatial and temporal proteomic analysis revealed that factors involved in plant defence, metabolism, reaction wood formation and lateral root development were differentially expressed in the various sectors of bent vs. control roots, seemingly in relation to the distribution of mechanical forces along the stressed woody taproots. A complex interplay among different signal transduction pathways involving reactive oxygen species appears to modulate these responses. Conclusions Poplar woody root uses different temporal and spatial mechanisms to respond to mechanical stress. Long-term bending treatment seem to reinforce the defence machinery, thereby enabling the taproot to better overcome winter and to be ready to resume growth earlier than controls. PMID:22437664

  8. Highly efficient CRISPR/Cas9-mediated targeted mutagenesis of multiple genes in Populus.

    Science.gov (United States)

    Liu, Ting-ting; Fan, Di; Ran, Ling-yu; Jiang, Yuan-zhong; Liu, Rui; Luo, Ke-ming

    2015-10-01

    The typeⅡCRISPR/Cas9 system (Clustered regularly interspaced short palindromic repeats /CRISPR-associated 9) has been widely used in bacteria, yeast, animals and plants as a targeted genome editing technique. In previous work, we have successfully knocked out the endogenous phytoene dehydrogenase (PDS) gene in Populus tomentosa Carr. using this system. To study the effect of target design on the efficiency of CRISPR/Cas9-mediated gene knockout in Populus, we analyzed the efficiency of mutagenesis using different single-guide RNA (sgRNA) that target PDS DNA sequence. We found that mismatches between the sgRNA and the target DNA resulted in decreased efficiency of mutagenesis and even failed mutagenesis. Moreover, complementarity between the 3' end nucleotide of sgRNA and target DNA is especially crucial for efficient mutagenesis. Further sequencing analysis showed that two PDS homologs in Populus, PtPDS1 and PtPDS2, could be knocked out simultaneously using this system with 86.4% and 50% efficiency, respectively. These results indicated the possibility of introducing mutations in two or more endogenous genes efficiently and obtaining multi-mutant strains of Populus using this system. We have indeed generated several knockout mutants of transcription factors and structural genes in Populus, which establishes a foundation for future studies of gene function and genetic improvement of Populus.

  9. Comparative proteomic analysis of Populus trichocarpa early stem from primary to secondary growth.

    Science.gov (United States)

    Liu, Jinwen; Hai, Guanghui; Wang, Chong; Cao, Shenquan; Xu, Wenjing; Jia, Zhigang; Yang, Chuanping; Wang, Jack P; Dai, Shaojun; Cheng, Yuxiang

    2015-08-03

    Wood is derived from the secondary growth of tree stems. In this study, we investigated the global changes of protein abundance in Populus early stems using a proteomic approach. Morphological and histochemical analyses revealed three typical stages during Populus early stems, which were the primary growth stage, the transition stage from primary to secondary growth and the secondary growth stage. A total of 231 spots were differentially abundant during various growth stages of Populus early stems. During Populus early stem lignifications, 87 differential spots continuously increased, while 49 spots continuously decreased. These two categories encompass 58.9% of all differential spots, which suggests significant molecular changes from primary to secondary growth. Among 231 spots, 165 unique proteins were identified using LC-ESI-Q-TOF-MS, which were classified into 14 biological function groups. The proteomic characteristics indicated that carbohydrate metabolism, oxido-reduction, protein degradation and secondary cell wall metabolism were the dominantly occurring biochemical processes during Populus early stem development. This study helps in elucidating biochemical processes and identifies potential wood formation-related proteins during tree early stem development. It is a comprehensive proteomic investigation on tree early stem development that, for the first time, reveals the overall molecular networks that occur during Populus early stem lignifications. Copyright © 2015. Published by Elsevier B.V.

  10. The Forest-Atmospheric Carbon Transfer and Storage-II (FACTS-II): Aspen FACE project

    Energy Technology Data Exchange (ETDEWEB)

    Karnosky, D.F.; Pregitzer, K. [Michigan Technological Univ., Houghton, MI (United States). School of Forestry and Wood Products; Hendrey, G. [Brookhaven National Lab., Upton, NY (United States); Isebrands, J.G. [Forest Service, Rhinelander, WI (United States)

    1998-02-01

    The FACTS II (Aspen FACE) infrastructure including 12 FACE rings, a central control facility, a central CO{sub 2} and O{sub 3} receiving and storage area, a central O{sub 3} generation system, and a dispensing system for CO{sub 2} and O{sub 3} was completed in 1997. The FACE rings were planted with over 10,000 plants (aspen, birch and maple). The entire system was thoroughly tested for both CO{sub 2} and O{sub 3} and was shown to be effective in delivering elevated CO{sub 2} and/or O{sub 3} on demand and at predetermined set points. The NCASI support to date has been extremely helpful in matching support for federal grants.

  11. THE FOREST-ATMOSPHERIC CARBON TRANSFER AND STORAGE-II (FACTS-II): ASPEN FACE PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    KARNOSKY,D.F.; HENDREY,G.; PREGITZER,K.; ISEBRANDS,J.G.

    1998-02-01

    The FACTS II (ASPEN FACE) infrastructure including 12 FACE [Free-Air Carbon dioxide Enrichment] rings, a central control facility, a central CO{sub 2} and O{sub 2} receiving and storage area, a central O{sub 3} generation system, and a dispensing system for CO{sub 2} and O{sub 3} was completed in 1997. The FACE rings were planted with over 10,000 plants (aspen, birch and maple). The entire system was thoroughly tested for both CO{sub 2} and O{sub 3} and was shown to be effective in delivering elevated CO{sub 2} and/or O{sub 3} on demand and at predetermined set points. The NCASI support to date has been extremely helpful in matching support for federal grants.

  12. ASPEN Plus Simulation of CO2 Recovery Process

    Energy Technology Data Exchange (ETDEWEB)

    White, Charles W. [EG& G Technical Services, Inc., Morgantown, WV (United States)

    2002-09-30

    ASPEN Plus simulations have been created for a CO2 capture process based on adsorption by monoethanolamine (MEA). Three separate simulations were developed, one each for the flue gas scrubbing, recovery, and purification sections of the process. Although intended to work together, each simulation can be used and executed independently. The simulations were designed as template simulations to be added as a component to other more complex simulations. Applications involving simple cycle or hybrid power production processes were targeted. The default block parameters were developed based on a feed stream of raw flue gas of approximately 14 volume percent CO2 with a 90% recovery of the CO2 as liquid. This report presents detailed descriptions of the process sections as well as technical documentation for the ASPEN simulations including the design basis, models employed, key assumptions, design parameters, convergence algorithms, and calculated outputs.

  13. Effect of Cyclic Loading on Modulus of Elasticity of Aspen Wood

    OpenAIRE

    Milan Gaff; Miroslav Gašparík

    2014-01-01

    This article investigates the modulus of elasticity of solid and laminated aspen wood of various thicknesses after cyclic loading. A three-point static bending test was carried out to determine the modulus of elasticity. Cyclically loaded samples were compared with samples without cyclic loading. For the laminated wood, the results demonstrated a statistically significant impact of cyclic loading on the elasticity modulus. In contrast, no significant impact of cyclic loading was shown for the...

  14. A system for predicting the amount of Phellinus (Fomes) igniarius rot in trembling aspen stands

    Science.gov (United States)

    Robert L. Anderson; Arthur L. Jr. Schipper

    1978-01-01

    The occurrence of Phellinus (Fomes) igniarius white trunk rot in 45- to 50-year-old trembling aspen stands can be predicted by applying a constant to the stand basal area with P. igniarius conks to estimate the total basal area with P. igniarius rot. Future decay projections can be made by reapplying the basal area of hidden decay for each 6 years projected. This paper...

  15. Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chung-Jui Tsai; Mark F. Davis; Vincent L. Chiang

    2004-11-10

    As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspen in order to produce trees with reduced lignin content, more reactive lignin structures and increased cellulose content. Transgenic aspen trees with reduced lignin content have already been achieved, prior to the start of this project, by antisense downregulation of a 4-coumarate:coenzyme A ligase gene (Hu et al., 1999 Nature Biotechnol 17: 808- 812). The primary objective of this study was to genetically augment syringyl lignin biosynthesis in these low-lignin trees in order to enhance lignin reactivity during chemical pulping. To accomplish this, both aspen and sweetgum genes encoding coniferaldehyde 5-hydroxylase (Osakabe et al., 1999 PNAS 96: 8955-8960) were targeted for over-expression in wildtype or low-lignin aspen under control of either a constitutive or a xylem-specific promoter. A second objective for this project was to develop reliable and cost-effective methods, such as pyrolysis Molecular Beam Mass Spectrometry and NMR, for rapid evaluation of cell wall chemical components of transgenic wood samples. With these high-throughput techniques, we observed increased syringyl-to-guaiacyl lignin ratios in the transgenic wood samples, regardless of the promoter used or gene origin. Our results confirmed that the coniferaldehyde 5-hydroxylase gene is key to syringyl lignin biosynthesis. The outcomes of this research should be readily applicable to other pulpwood species, and promise to bring direct economic and environmental benefits to the pulp and paper industry.

  16. Modeling the Removal of Xenon from Lithium Hydrate with Aspen HYSYS

    Science.gov (United States)

    Efthimion, Phillip; Gentile, Charles

    2011-10-01

    The Laser Inertial Fusion Engine (LIFE) project mission is to provide a long-term, carbon-free source of sustainable energy, in the form of electricity. A conceptual xenon removal system has been modeled with the aid of Aspen HYSYS, a chemical process simulator. Aspen HYSYS provides excellent capability to model chemical flow processes, which generates outputs which includes specific variables such as temperature, pressure, and molar flow. The system is designed to strip out hydrogen isotopes deuterium and tritium. The base design bubbles plasma exhaust laden with x filled with liquid helium. The system separates the xenon from the hydrogen, deuterium, and tritium with a lithium hydrate and a lithium bubbler. After the removal of the hydrogen and its isotopes, the xenon is then purified by way of the process of cryogenic distillation. The pure hydrogen, deuterium, and tritium are then sent to the isotope separation system (ISS). The removal of xenon is an integral part of the laser inertial fusion engine and Aspen HYSYS is an excellent tool to calculate how to create pure xenon.

  17. Usando modelos de usuario en matlab® en la interfaz de aspen plus® con excel® como puente

    OpenAIRE

    Fontalvo Alzate, Javier

    2014-01-01

    El diseño de procesos intensificados y de nuevas tecnologías requiere de herramientas de simulación como Aspen Plus®. Sin embargo, las operaciones unitarias que no se incluyen en Aspen Plus pueden ser simuladas usando Matlab e integradas con la interfaz de Aspen Plus. De esta forma se pueden aprovechar todas la capacidades de Aspen plus como la optimización, el análisis de sensibilidad y la estimación de costos. Este artículo describe en detalle cómo implementar esta integración. La interfaz ...

  18. Genome scale transcriptome analysis of shoot organogenesis in Populus.

    Science.gov (United States)

    Bao, Yanghuan; Dharmawardhana, Palitha; Mockler, Todd C; Strauss, Steven H

    2009-11-17

    Our aim is to improve knowledge of gene regulatory circuits important to dedifferentiation, redifferentiation, and adventitious meristem organization during in vitro regeneration of plants. Regeneration of transgenic cells remains a major obstacle to research and commercial deployment of most taxa of transgenic plants, and woody species are particularly recalcitrant. The model woody species Populus, due to its genome sequence and amenability to in vitro manipulation, is an excellent species for study in this area. The genes recognized may help to guide the development of new tools for improving the efficiency of plant regeneration and transformation. We analyzed gene expression during poplar in vitro dedifferentiation and shoot regeneration using an Affymetrix array representing over 56,000 poplar transcripts. We focused on callus induction and shoot formation, thus we sampled RNAs from tissues: prior to callus induction, 3 days and 15 days after callus induction, and 3 days and 8 days after the start of shoot induction. We used a female hybrid white poplar clone (INRA 717-1 B4, Populus tremula x P. alba) that is used widely as a model transgenic genotype. Approximately 15% of the monitored genes were significantly up-or down-regulated when controlling the false discovery rate (FDR) at 0.01; over 3,000 genes had a 5-fold or greater change in expression. We found a large initial change in expression after the beginning of hormone treatment (at the earliest stage of callus induction), and then a much smaller number of additional differentially expressed genes at subsequent regeneration stages. A total of 588 transcription factors that were distributed in 45 gene families were differentially regulated. Genes that showed strong differential expression included components of auxin and cytokinin signaling, selected cell division genes, and genes related to plastid development and photosynthesis. When compared with data on in vitro callogenesis in Arabidopsis, 25% (1

  19. Genome scale transcriptome analysis of shoot organogenesis in Populus

    Directory of Open Access Journals (Sweden)

    Mockler Todd C

    2009-11-01

    Full Text Available Abstract Background Our aim is to improve knowledge of gene regulatory circuits important to dedifferentiation, redifferentiation, and adventitious meristem organization during in vitro regeneration of plants. Regeneration of transgenic cells remains a major obstacle to research and commercial deployment of most taxa of transgenic plants, and woody species are particularly recalcitrant. The model woody species Populus, due to its genome sequence and amenability to in vitro manipulation, is an excellent species for study in this area. The genes recognized may help to guide the development of new tools for improving the efficiency of plant regeneration and transformation. Results We analyzed gene expression during poplar in vitro dedifferentiation and shoot regeneration using an Affymetrix array representing over 56,000 poplar transcripts. We focused on callus induction and shoot formation, thus we sampled RNAs from tissues: prior to callus induction, 3 days and 15 days after callus induction, and 3 days and 8 days after the start of shoot induction. We used a female hybrid white poplar clone (INRA 717-1 B4, Populus tremula × P. alba that is used widely as a model transgenic genotype. Approximately 15% of the monitored genes were significantly up-or down-regulated when controlling the false discovery rate (FDR at 0.01; over 3,000 genes had a 5-fold or greater change in expression. We found a large initial change in expression after the beginning of hormone treatment (at the earliest stage of callus induction, and then a much smaller number of additional differentially expressed genes at subsequent regeneration stages. A total of 588 transcription factors that were distributed in 45 gene families were differentially regulated. Genes that showed strong differential expression included components of auxin and cytokinin signaling, selected cell division genes, and genes related to plastid development and photosynthesis. When compared with data on in

  20. Comparative genome mapping among Populus adenopoda, P. alba, P. deltoides, P. euramericana and P. trichocarpa.

    Science.gov (United States)

    Wang, Yuanxiu; Zhang, Bo; Sun, Xiaoyan; Tan, Biyue; Xu, Li-An; Huang, Minren; Wang, Mingxiu

    2011-01-01

    Among the genus Populus, the sections Populus (white poplar), Aigeiros Duby (black poplar) and Tacamahaca Spach contain many tree species of economical and ecological important properties. Two parental maps for the inter-specific hybrid population of Populus adenopoda × P. alba (two species of Populus section) were constructed based on SSR and SRAP markers by means of a two-way pseudo-test cross mapping strategy. The same set of SSR markers developed from the P. trichocarpa (belonging to Tacamahaca section) genome which were used to construct the maps of P. deltoides and P. euramericana (two species of Aigeiros section) was chosen to analyze the genotype of the experimental population of P. adenopoda × P. alba. Using the mapped SSR markers as allelic bridges, the alignment of the white and black poplar maps to each other and to the P. trichocarpa physical map was conducted. The alignment showed high degree of marker synteny and colinearity and the closer relationship between Aigeiros and Tacamahaca sections than that of Populus and Tacamahaca. Moreover, there was evidence for the chromosomal duplication and inter-chromosomal reorganization involving some poplar linkage groups, suggesting a complicated course of fission or fusion in one of the lineages. A poplar consensus map based on the comparisons could be constructed will be useful in practical applications including marker assisted selection.

  1. Stock characterization and improvement: DNA fingerprinting and cold tolerance of Populus and Salix clones

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Dolly; Hubbes, M.; Zsuffa, L. [Toronto Univ., ON (Canada). Faculty of Forestry; Tsarouhas, V.; Gullberg, U. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics; Howe, G.; Hackett, W.; Gardner, G.; Furnier, G. [Minnesota Univ., St. Paul, MN (United States). Dept. of Forest Resources; Tuskan, G. [Oak Ridge National Lab., TN (United States)

    1998-12-31

    Molecular characterization of advanced-generation pedigrees and evaluation of cold tolerance are two aspects of Populus and Salix genetic improvement programmes worldwide that have traditionally received little emphasis. As such, chloroplast DNA markers were tested as a means of determining multi-generation parental contributions to hybrid progeny. Likewise, greenhouse, growth chamber and field studies were used to assess cold tolerance in Populus and Salix. Chloroplast DNA markers did not reveal size polymorphisms among four tested Populus species, but did produce sequence polymorphisms between P. maximowiczii and P. trichocarpa. Additional crosses between multiple genotypes from each species are being used to evaluate the utility of the detected polymorphism for ascertaining parentage within interspecific crosses. Short-day, cold tolerance greenhouse studies revealed that bud set date and frost damage are moderately heritable and genetically correlated in Populus. The relationship between greenhouse and field studies suggests that factors other than short days contribute to cold tolerance in Populus. In Salix, response to artificial fall conditioning varied among full-sibling families, with the fastest growing family displaying the greatest amount of cold tolerance 26 refs, 3 tabs

  2. A survey of Populus PIN-FORMED family genes reveals their diversified expression patterns.

    Science.gov (United States)

    Liu, Bobin; Zhang, Jin; Wang, Lin; Li, Jianbo; Zheng, Huanquan; Chen, Jun; Lu, Mengzhu

    2014-06-01

    The plant hormone auxin is a key regulator of plant development, and its uneven distribution maintained by polar intercellular auxin transport in plant tissues can trigger a wide range of developmental processes. Although the roles of PIN-FORMED (PIN) proteins in intercellular auxin flow have been extensively characterized in Arabidopsis, their roles in woody plants remain unclear. Here, a comprehensive analysis of PIN proteins in Populus is presented. Fifteen PINs are encoded in the genome of Populus, including four PIN1s, one PIN2, two PIN3s, three PIN5s, three PIN6s, and two PIN8s. Similar to Arabidopsis AtPIN proteins, PtPINs share conserved topology and transmembrane domains, and are either plasma membrane- or endoplasmic reticulum-localized. The more diversified expansion of the PIN family in Populus, comparing to that in Arabidopsis, indicates that some auxin-regulated developmental processes, such as secondary growth, may exhibit unique features in trees. More importantly, different sets of PtoPINs have been found to be strongly expressed in the roots, leaves, and cambium in Populus; the dynamic expression patterns of selected PtoPINs were further examined during the regeneration of shoots and roots. This genome-wide analysis of the Populus PIN family provides important cues for their potential roles in tree growth and development. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Identification of phasiRNAs and their drought- responsiveness in Populus trichocarpa.

    Science.gov (United States)

    Shuai, Peng; Su, Yanyan; Liang, Dan; Zhang, Zhoujia; Xia, Xinli; Yin, Weilun

    2016-10-01

    Phased, secondary, small interfering RNA (phasiRNA) perform essential biological functions in plants. However, limited information is available on the role of phasiRNA genes in Populus (poplar), especially during drought stress. In this study, we identified 20 PHAS loci generating 91 phasiRNA in the genome of the model forest tree Populus trichocarpa (P. trichocarpa; western balsam-poplar) using the control and drought libraries. Our analysis indicated that six PHAS (PtPHA14-20) initiated by two Populus-specific miRNAs (miR6445 and miR6427) were specific to Populus. In addition, a total of 47 phasiRNA were found to be drought responsive, and five of them were confirmed by RT-qPCR. The phase cleavage of three PHAS loci by miRNA, and degradation of nine transcript targets by phasiRNA were experimentally confirmed based on degradome data. The identification of these Populus phasiRNA will contribute to a better understanding of their function and regulation during drought stress. © 2016 Federation of European Biochemical Societies.

  4. Gene Expression Differences between High-Growth Populus Allotriploids and Their Diploid Parents

    Directory of Open Access Journals (Sweden)

    Shiping Cheng

    2015-03-01

    Full Text Available Polyploid breeding is important in Populus genetic improvement programs because polyploid trees generally display increased height growth compared to their diploid parents. However, the genetic mechanism underlying this phenomenon remains unknown. In the present study, apical bud transcriptomes of vigorous, fast growing Populus allotriploid progeny genotypes and their diploid parents were sequenced and analyzed. We found that these allotriploids exhibited extensive transcriptomic diversity. In total, 6020 differentially expressed genes (DEGs were found when the allotriploid progeny and their parents were compared, among which 791 overlapped between the allotriploids and both parents. Many genes associated with cell differentiation and meristem development were preferentially expressed in apical buds of the fast growing Populus allotriploids compared to their diploid parents. In addition, many auxin-, gibberellin-, and jasmonic acid-related genes were also preferentially expressed in the allotriploids compared to their parents. Our findings show that allotriploidy can have considerable effects on duplicate gene expression in Populus. In particular we identified and considered DEGs that provide important clues for improving our mechanistic understanding of positive heterosis of vigor- and growth-related traits in Populus allotriploids.

  5. Rhizobium cellulosilyticum sp. nov., isolated from sawdust of Populus alba.

    Science.gov (United States)

    García-Fraile, Paula; Rivas, Raúl; Willems, Anne; Peix, Alvaro; Martens, Miet; Martínez-Molina, Eustoquio; Mateos, Pedro F; Velázquez, Encarna

    2007-04-01

    During a study of polysaccharide-hydrolysing bacteria present in different plant sources, two strains were isolated from pulverized decaying wood of Populus alba and classified in the genus Rhizobium on basis of their almost complete 16S rRNA gene sequences. Their closest phylogenetic relatives were Rhizobium galegae USDA 4128(T) and Rhizobium huautlense S02(T), with 98.2 and 98.1 % 16S rRNA gene sequence similarity, respectively. recA and atpD sequence analysis showed that these species have less than 88 and 92 % similarity, respectively, to the novel strains. In contrast to their closest phylogenetic relatives, the two strains showed strong cellulase activity on plates containing CM-cellulose as a carbon source. They were also distinguishable from these species on the basis of other phenotypic characteristics. The strains were able to induce ineffective nodules on Medicago sativa and the sequence of their nodD gene was phylogenetically close to that of Ensifer meliloti 1021 (99.6 % similarity). DNA-DNA hybridization values ranged from 10 to 22 % with respect to R. galegae USDA 4128(T) and 14 to 25 % with respect to R. huautlense S02(T), showing that the strains from this study belong to a novel species, for which the name Rhizobium cellulosilyticum sp. nov. is proposed. The type strain is ALA10B2(T) (=LMG 23642(T)=DSM 18291(T)=CECT 7176(T)).

  6. Genetic diversity in Populus nigra plantations from west of Iran

    Directory of Open Access Journals (Sweden)

    Afrooz Alimohamadi

    2012-11-01

    Full Text Available In order to adopt strategies for forest conservation and development,it is necessary to estimate the amount and distribution of genetic diversity in existing populations of poplar in Iran. In this study, the genetic diversity between eight stands of Populus nigra established in Kermanshah province was evaluated on the basis of molecular and morphological markers. To amplify microsatellite loci (WPMS09, WPMS16 and WPMS18, DNA extraction from young and fresh leaveswas done. Various conditions of the PCR assay were examined and to evaluate the morphological variation of the morphological characters leaves (consist of 19 traits were measured. In addition, height growth was measured, to evaluate the growth function of the stands in homogeneous conditions. Genetic diversity in termof polymorphic loci was 0%, because three investigated microsatellite loci were monomorphic. The total number of alleles for 3 microsatellite loci was 6 (na = 2, ne = 2, heo = 1, hee = 0.51. Genetic identity based on Nei was 100%, so genetic distance was 0%. The whole sampled trees represented the same thus the genotype. No significant differences between the mean values of all morphological characters and height growth were revealed. Observed genetic similarity gave indication that same ramets had been selected to plant in poplar plantation established in Kermanshah province.These results suggest the need for an initial evaluation of the genetic diversity in selected ramets for planting in plantation to avoid repetition.

  7. Rhizobacteria of Populus euphratica Promoting Plant Growth Against Heavy Metals.

    Science.gov (United States)

    Zhu, Donglin; Ouyang, Liming; Xu, Zhaohui; Zhang, Lili

    2015-01-01

    The heavy metal-resistant bacteria from rhizospheric soils of wild Populus euphratica forest growing in arid and saline area of northwestern China were investigated by cultivation-dependent methods. After screening on medium sparked with zinc, copper, nickel and lead, 146 bacteria strains with different morphology were isolated and most of them were found to be resistant to at least two kinds of heavy metals. Significant increase in fresh weight and leaf surface area of Arabidopsis thaliana seedlings under metal stress were noticed after inoculated with strains especially those having multiple-resistance to heavy metals such as Phyllobacterium sp. strain C65. Investigation on relationship between auxin production and exogenous zinc concentration revealed that Phyllobacterium sp. strain C65 produced auxin, and production decreased as the concentration of zinc in medium increased. For wheat seedlings treated with zinc of 2 mM, zinc contents in roots of inoculated plants decreased by 27% (P < 0.05) compared to the uninoculated control. Meanwhile, zinc accumulation in the above-ground tissues increased by 22% (P < 0.05). The translocation of zinc from root to above-ground tissues induced by Phyllobacterium sp. strain C65 helped host plants extract zinc from contaminated environments more efficiently thus alleviated the growth inhibition caused by heavy metals.

  8. Genetic diversity in Populus nigra plantations from west of Iran

    Directory of Open Access Journals (Sweden)

    Afrooz Alimohamadi

    2012-12-01

    Full Text Available In order to adopt strategies for forest conservation and development, it is necessary to estimate the amount and distribution of genetic diversity in existing populations of poplar in Iran. In this study, the genetic diversity between eight stands of Populus nigra established in Kermanshah province was evaluated on the basis of molecular and morphological markers. To amplify microsatellite loci (WPMS09, WPMS16 and WPMS18, DNA extraction from young and fresh leaveswas done. Various conditions of the PCR assay were examined and to evaluate the morphological variation of the morphological characters leaves (consist of 19 traits were measured. In addition, height growth was measured, to evaluate the growth function of the stands in homogeneous conditions. Genetic diversity in term of polymorphic loci was 0%, because three investigated microsatellite loci were monomorphic. The total number of alleles for 3 microsatellite loci was 6 (na = 2, ne = 2, heo = 1, hee = 0.51. Genetic identity based on Nei was 100%, so genetic distance was 0%. The whole sampled trees represented the same thus the genotype. No significant differences between the mean values of all morphological characters and height growth were revealed. Observed genetic similarity gave indication that same ramets had been selected to plant in poplar plantation established in Kermanshah province. These results suggest the need for an initial evaluation of the genetic diversity in selected ramets for planting in plantation to avoid repetition.  

  9. Shoot morphogenesis associated with flowering in Populus deltoides (Salicaceae).

    Science.gov (United States)

    Yuceer, Cetin; Land, Samuel B; Kubiske, Mark E; Harkess, Richard L

    2003-02-01

    Temporal and spatial formation and differentiation of axillary buds in developing shoots of mature eastern cottonwood (Populus deltoides) were investigated. Shoots sequentially initiate early vegetative, floral, and late vegetative buds. Associated with these buds is the formation of three distinct leaf types. In May of the first growing season, the first type begins forming in terminal buds and overwinters as relatively developed foliar structures. These leaves bear early vegetative buds in their axils. The second type forms late in the first growing season in terminal buds. These leaves form floral buds in their axils the second growing season. The floral bud meristems initiate scale leaves in April and begin forming floral meristems in the axils of the bracts in May. The floral meristems subsequently form floral organs by the end of the second growing season. The floral buds overwinter with floral organs, and anthesis occurs in the third growing season. The third type of leaf forms and develops entirely outside the terminal buds in the second growing season. These leaves bear the late vegetative buds in their axils. On the basis of these and other supporting data, we hypothesize a 3-yr flowering cycle as opposed to the traditional 2-yr cycle in eastern cottonwood.

  10. Effects of induction treatments on flowering in Populus deltoides.

    Science.gov (United States)

    Yuceer, Cetin; Kubiske, Mark E; Harkess, Richard L; Land, Samuel B

    2003-05-01

    Stimulation of early flowering is required to shorten breeding cycles of eastern cottonwood (Populus deltoides Bartr. ex Marsh. var. deltoides), a commercially important and fast-growing hardwood species. A series of experiments was conducted to evaluate the influence of various treatments on flowering in rooted cuttings from mature and juvenile trees. A combined treatment of water stress, root pruning and paclobutrazol was applied to 3-month-old rooted cuttings from mature trees. These cuttings had been subjected to root restriction and long days. All treated plants flowered, whereas no untreated plants formed flower buds. One-year-old rooted cuttings from juvenile trees did not flower when treated with either paclobutrazol, paclobutrazol plus water stress, paclobutrazol plus root pruning, or paclobutrazol plus girdling. This was true both under continuous or periodic growth. Assessment of the lack of flowering in juvenile trees may require an integrated approach that investigates environmental or physiological stimuli, assimilate shift, gibberellic acid type and concentration, and flowering-time gene activity in the new shoots of mature and juvenile cottonwood trees.

  11. Chemical responses to modified lignin composition in tension wood of hybrid poplar (Populus tremula x Populus alba).

    Science.gov (United States)

    Al-Haddad, Jameel M; Kang, Kyu-Young; Mansfield, Shawn D; Telewski, Frank W

    2013-04-01

    The effect of altering the expression level of the F5H gene was investigated in three wood tissues (normal, opposite and tension wood) in 1-year-old hybrid poplar clone 717 (Populus tremula × Populus alba L.), containing the F5H gene under the control of the C4H promoter. Elevated expression of the F5H gene in poplar has been previously reported to increase the percent syringyl content of lignin. The wild-type and three transgenic lines were inclined 45° for 3 months to induce tension wood formation. Tension and opposite wood from inclined trees, along with normal wood from control trees, were analyzed separately for carbohydrates, lignin, cellulose crystallinity and microfibril angle (MFA). In the wild-type poplar, the lignin in tension wood contained a significantly higher percentage of syringyl than normal wood or opposite wood. However, there was no significant difference in the percent syringyl content of the three wood types within each of the transgenic lines. Increasing the F5H gene expression caused an increase in the percent syringyl content and a slight decrease in the total lignin in normal wood. In tension wood, the addition of a gelatinous layer in the fiber walls resulted in a consistently lower percentage of total lignin in the tissue. Acid-soluble lignin was observed to increase by up to 2.3-fold in the transgenic lines. Compared with normal wood and opposite wood, cell wall crystallinity in tension wood was higher and the MFA was smaller, as expected, with no evidence of an effect from modifying the syringyl monomer ratio. Tension wood in all the lines contained consistently higher total sugar and glucose percentages when compared with normal wood within the respective lines. However, both sugar and glucose percentages were lower in the tension wood of transgenic lines when compared with the tension wood of wild-type trees. Evaluating the response of trees with altered syringyl content to gravity will improve our understanding of the changes

  12. Phylogenetic and stress-responsive expression analysis of 20 WRKY genes in Populus simonii × Populus nigra.

    Science.gov (United States)

    Zhao, Hui; Wang, Sui; Chen, Su; Jiang, Jing; Liu, Guifeng

    2015-07-01

    WRKY transcription factors play important roles in regulating biotic and abiotic stress responses in plants. Although a plethora of studies have revealed the functions and mechanisms of some WRKYs in various plants, the studies of WRKYs in woody plants especially tree species under different abiotic and biotic stress conditions are still not well characterized. In this study, we selected 20 Populus simonii×Populus nigra WRKY genes based on our previous transcriptome study, and characterized these genes by phylogenetic analysis to investigate their evolutionary relations, then studied their expression patterns under NaCl, NaHCO3, PEG6000, CdCl2 and Alternaria alternata (Fr.) Keissl treatments that mimic the salt, alkalinity, drought, heavy metal and fungal infection conditions. The phylogenetic analysis showed that these 20 genes can be divided into five clades (Groups I, IIa, IIb, IIc and III) and all of their WRKY domains are conserved except for an N-terminal single amino acid mutation in PsnWRKY8. Before conducting quantitative real time PCR calculation, we evaluated five candidate reference genes under different stress treatments, and chose At4g33380-like as the reference gene for salt stress, Actin for alkalinity stress, UBQ for drought stress, TUA for heavy metal stress, and 18S rRNA for pathogen infection stress. The final qRT-PCR analysis indicated that 20/20, 20/20, and 15/20 PsnWRKYs were downregulated under salt, alkali and drought stresses, and 14/20 and 19/20 PsnWRKYs were upregulated under heavy metal and pathogen stresses. Members from the same clade tended to present similar expression patterns. In addition, we observed noticeable changes in the expression of PsnWRKY11 (increased by 41 times) and PsnWRKY20 (increased by 141 times) under pathogen infection condition, implying that these two genes are potentially important for the disease resistance of P. simonii × P. nigra. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Uptake of macro- and micro-nutrients into leaf, woody, and root tissue of Populus after irrigation with landfill leachate

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Bart T. Sexton; Richard B. Hall

    2008-01-01

    Information about macro- and micro-nutrient uptake and distribution into tissues of Populus irrigated with landfill leachate helps to maximize biomass production and understand impacts of leachate chemistry on tree health. We irrigated eight Populus clones (NC 13460, NCI4O18, NC14104, NC14106, DM115, DN5, NM2, NM6) with fertilized (N, P, K) well...

  14. Sodium and chloride accumulation in leaf, woody, and root tissue of Populus after irrigation with landfill leachate

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Bart Sexton; Richard B. Hall

    2008-01-01

    The response of Populus to irrigation sources containing elevated levels of sodium (Na+) and chloride (Cl-) is poorly understood. We irrigated eight Populus clones with fertilized well water (control) (N, P, K) or municipal solid waste landfill leachate weekly during 2005 and 2006 in...

  15. Effects of Clone, Silvicultural, and Miticide Treatments on Cottonwood Leafcurl Mite (Acari: Eriophyidae) Damage in Plantation Populus

    Science.gov (United States)

    David R. Coyle

    2002-01-01

    Aculops lobuliferus (Keifer) is a little known pest of plantation Populus spp., which is capable of causing substantial damage. This is the First documented occurrence of A. lobuliferus in South Carolina. Previous anecdotal data indicated clonal variation in Populus susceptibility to A...

  16. Clonal variation in morphology of Populus root systems following irrigation with landfill leachate or water during 2 years of establishment

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; David R. Coyle; Richard B. Hall; Edmund O. Bauer

    2009-01-01

    Increased municipal solid waste generation in North America has prompted the use of Populus for phytoremediation of waste waters including landfill leachate. Populus species and hybrids are ideal for such applications because of their high water usage rates, fast growth, and extensive root systems. Adventitious rooting (i.e.,...

  17. The Populus ARBORKNOX1 homeodomain transcription factor regulates woody growth through binding to evolutionarily conserved target genes of diverse function

    Science.gov (United States)

    Lijun Liu; Matthew S. Zinkgraf; H. Earl Petzold; Eric P. Beers; Vladimir Filkov; Andrew Groover

    2014-01-01

    The class I KNOX homeodomain transcription factor ARBORKNOX1 (ARK1) is a key regulator of vascular cambium maintenance and cell differentiation in Populus. Currently, basic information is lacking concerning the distribution, functional characteristics, and evolution of ARK1 binding in the Populus genome.

  18. Genome-Wide Identification, Evolutionary Expansion, and Expression Profile of Homeodomain-Leucine Zipper Gene Family in Poplar (Populus trichocarpa)

    Science.gov (United States)

    Hu, Ruibo; Chi, Xiaoyuan; Chai, Guohua; Kong, Yingzhen; He, Guo; Wang, Xiaoyu; Shi, Dachuan; Zhang, Dongyuan; Zhou, Gongke

    2012-01-01

    Background Homeodomain-leucine zipper (HD-ZIP) proteins are plant-specific transcriptional factors known to play crucial roles in plant development. Although sequence phylogeny analysis of Populus HD-ZIPs was carried out in a previous study, no systematic analysis incorporating genome organization, gene structure, and expression compendium has been conducted in model tree species Populus thus far. Principal Findings In this study, a comprehensive analysis of Populus HD-ZIP gene family was performed. Sixty-three full-length HD-ZIP genes were found in Populus genome. These Populus HD-ZIP genes were phylogenetically clustered into four distinct subfamilies (HD-ZIP I–IV) and predominately distributed across 17 linkage groups (LG). Fifty genes from 25 Populus paralogous pairs were located in the duplicated blocks of Populus genome and then preferentially retained during the sequential evolutionary courses. Genomic organization analyses indicated that purifying selection has played a pivotal role in the retention and maintenance of Populus HD-ZIP gene family. Microarray analysis has shown that 21 Populus paralogous pairs have been differentially expressed across different tissues and under various stresses, with five paralogous pairs showing nearly identical expression patterns, 13 paralogous pairs being partially redundant and three paralogous pairs diversifying significantly. Quantitative real-time RT-PCR (qRT-PCR) analysis performed on 16 selected Populus HD-ZIP genes in different tissues and under both drought and salinity stresses confirms their tissue-specific and stress-inducible expression patterns. Conclusions Genomic organizations indicated that segmental duplications contributed significantly to the expansion of Populus HD-ZIP gene family. Exon/intron organization and conserved motif composition of Populus HD-ZIPs are highly conservative in the same subfamily, suggesting the members in the same subfamilies may also have conservative functionalities

  19. Genome-wide identification, evolutionary expansion, and expression profile of homeodomain-leucine zipper gene family in poplar (Populus trichocarpa.

    Directory of Open Access Journals (Sweden)

    Ruibo Hu

    Full Text Available BACKGROUND: Homeodomain-leucine zipper (HD-ZIP proteins are plant-specific transcriptional factors known to play crucial roles in plant development. Although sequence phylogeny analysis of Populus HD-ZIPs was carried out in a previous study, no systematic analysis incorporating genome organization, gene structure, and expression compendium has been conducted in model tree species Populus thus far. PRINCIPAL FINDINGS: In this study, a comprehensive analysis of Populus HD-ZIP gene family was performed. Sixty-three full-length HD-ZIP genes were found in Populus genome. These Populus HD-ZIP genes were phylogenetically clustered into four distinct subfamilies (HD-ZIP I-IV and predominately distributed across 17 linkage groups (LG. Fifty genes from 25 Populus paralogous pairs were located in the duplicated blocks of Populus genome and then preferentially retained during the sequential evolutionary courses. Genomic organization analyses indicated that purifying selection has played a pivotal role in the retention and maintenance of Populus HD-ZIP gene family. Microarray analysis has shown that 21 Populus paralogous pairs have been differentially expressed across different tissues and under various stresses, with five paralogous pairs showing nearly identical expression patterns, 13 paralogous pairs being partially redundant and three paralogous pairs diversifying significantly. Quantitative real-time RT-PCR (qRT-PCR analysis performed on 16 selected Populus HD-ZIP genes in different tissues and under both drought and salinity stresses confirms their tissue-specific and stress-inducible expression patterns. CONCLUSIONS: Genomic organizations indicated that segmental duplications contributed significantly to the expansion of Populus HD-ZIP gene family. Exon/intron organization and conserved motif composition of Populus HD-ZIPs are highly conservative in the same subfamily, suggesting the members in the same subfamilies may also have conservative

  20. [Proof of the indigenous nature of Populus alba L. in the western Mediterranean Basin].

    Science.gov (United States)

    Roiron, Paul; Ali, Adam A; Guendon, Jean-Louis; Carcaillet, Christopher; Terral, Jean-Frédéric

    2004-02-01

    Around the western Mediterranean Basin, the ecological status of Populus alba, whether indigenous or introduced, is controversial. This note presents new palaeobotanical data based on analyses of leaf imprints from a travertine formation located in southern France. This travertine presents two levels with Populus alba imprints. The oldest level is dated back by 14C to the Early Holocene, i.e., 8890 +/- 70 BP. This demonstrates that Populus alba is an autochthonous species of the southern-France vegetation, removing speculations reporting that its distribution area was greatly influenced by Roman civilization. Finally, we discuss this new data in regard to other Pleistocene and Holocene deposits circum the Mediterranean Basin and in Europe, where this species was identified.

  1. PtrKOR1 is required for secondary cell wall cellulose biosynthesis in Populus.

    Science.gov (United States)

    Yu, Liangliang; Chen, Hongpeng; Sun, Jiayan; Li, Laigeng

    2014-11-01

    KORRIGAN (KOR), encoding an endo-1,4-β-glucanase, plays a critical role in the cellulose synthesis of plant cell wall formation. KOR sequence orthologs are duplicated in the Populus genome relative to Arabidopsis. This study reports an expression analysis of the KOR genes in Populus. The five PtrKOR genes displayed different expression patterns, suggesting that they play roles in different developmental processes. Through RNAi suppression, results demonstrated that PtrKOR1 is required for secondary cell wall cellulose formation in Populus. Together, the results suggest that the PtrKOR genes may play distinct roles in association with cell wall formation in different tissues. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Genome-wide analysis of Aux/IAA and ARF gene families in Populus trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    Kalluri, Udaya C [ORNL; DiFazio, Stephen P [West Virginia University; Brunner, A. [Virginia Polytechnic Institute and State University (Virginia Tech); Tuskan, Gerald A [ORNL

    2007-01-01

    Auxin/Indole-3-Acetic Acid (Aux/IAA) and Auxin Response Factor (ARF) transcription factors are key regulators of auxin responses in plants. A total of 35 Aux/IAA and 39 ARF genes were identified in the Populus genome. Comparative phylogenetic analysis revealed that the subgroups PoptrARF2, 6, 9 and 16 and PoptrIAA3, 16, 27 and 29 have differentially expanded in Populus relative to Arabidopsis. Activator ARFs were found to be two fold-overrepresented in the Populus genome. PoptrIAA and PoptrARF gene families appear to have expanded due to high segmental and low tandem duplication events. Furthermore, expression studies showed that genes in the expanded PoptrIAA3 subgroup display differential expression. The gene-family analysis reported here will be useful in conducting future functional genomics studies to understand how the molecular roles of these large gene families translate into a diversity of biologically meaningful auxin effects.

  3. Populus trichocarpa and Populus deltoides exhibit different metabolomic responses to colonization by the symbiotic fungus Laccaria bicolor.

    Science.gov (United States)

    Tschaplinski, Timothy J; Plett, Jonathan M; Engle, Nancy L; Deveau, Aurelie; Cushman, Katherine C; Martin, Madhavi Z; Doktycz, Mitchel J; Tuskan, Gerald A; Brun, Annick; Kohler, Annegret; Martin, Francis

    2014-06-01

    Within boreal and temperate forest ecosystems, the majority of trees and shrubs form beneficial relationships with mutualistic ectomycorrhizal (ECM) fungi that support plant health through increased access to nutrients as well as aiding in stress and pest tolerance. The intimate interaction between fungal hyphae and plant roots results in a new symbiotic "organ" called the ECM root tip. Little is understood concerning the metabolic reprogramming that favors the formation of this hybrid tissue in compatible interactions and what prevents the formation of ECM root tips in incompatible interactions. We show here that the metabolic changes during favorable colonization between the ECM fungus Laccaria bicolor and its compatible host, Populus trichocarpa, are characterized by shifts in aromatic acid, organic acid, and fatty acid metabolism. We demonstrate that this extensive metabolic reprogramming is repressed in incompatible interactions and that more defensive compounds are produced or retained. We also demonstrate that L. bicolor can metabolize a number of secreted defensive compounds and that the degradation of some of these compounds produces immune response metabolites (e.g., salicylic acid from salicin). Therefore, our results suggest that the metabolic responsiveness of plant roots to L. bicolor is a determinant factor in fungus-host interactions.

  4. Mathematical modeling of RDX and HMX metabolism in poplar (Populus deltoides x Populus nigra, DN34) tissue culture.

    Science.gov (United States)

    Mezzari, Melissa P; Van Aken, Benoit; Yoon, Jong M; Just, Craig L; Schnoor, Jerald L

    2004-01-01

    Three mathematical models were developed based on a fate study as an approach to define transformation pathways of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) within plant cells. [U-14C]RDX and [U-14C]HMX were added in Murashige and Skoog (MS) liquid media containing Populus deltoides x P. nigra (DN34) tissue cultures. Radioactivity of samples was analyzed using HPLC, a bio-oxidizer and liquid scintillation counter. Based on information collected, transformation pathways of nitramine compounds were fitted with the raw data obtained and using a modified "green liver" model. Ordinary differential equations were developed and simulations were performed with MicroMath Scientist version 2.0 (MicroMath Inc., St. Louis, MO, USA). The three models, with different sequential transformation processes, were tested in order to support the raw data (model I) and the assumptions of the modified "green liver" model (models II and III). The results showed a high correlation between the collected data and the simulated concentrations for all models. Thus, the simplest model developed (model I) is the best model description of these particular results. The results obtained suggest that the principle of parsimony should be applied. The "green liver"-based models also demonstrated a reliable approach for the investigation of degradation pathways of nitramines within plant cells.

  5. Physiological and transcriptional responses of two contrasting Populus clones to nitrogen stress.

    Science.gov (United States)

    Wang, Xiaoli; Li, Xiaodong; Zhang, Sheng; Korpelainen, Helena; Li, Chunyang

    2016-05-01

    The aim of this study was to reveal mechanisms responsible for nitrogen (N) stress in two contrasting Populus clones. Leaves of Nanlin 1388 (N stress-insensitive clone hybrids of Populus deltoides Bart.CV. × Populus euramericana (Dode) Guineir CV) and Nanlin 895 (N stress-sensitive clone hybrids of Populus deltoides Bart.CV. × Populus euramericana (Dode) Guineir CV) were harvested and analyzed. Different responses visible in photosynthesis, N and carbon contents, physiological traits, and chlorophyll were observed. The Solexa/Illumina's digital gene expression system was used to investigate differentially expressed miRNAs and mRNAs under N stress. Target profiling, and biological network and function analyses were also performed. Randomly selected mRNAs and miRNAs were validated by quantitative reverse transcription polymerase chain reaction. In all, 110 Nanlin 1388 and 122 Nanlin 895 miRNAs were differentially expressed, among which 34 and 23 miRNAs were newly found in the two clones, respectively. Under N stress, a total of 329 and 98 mRNAs were regulated in N stress-insensitive and -sensitive clones, respectively. Notably, the miR396 family and its regulated mRNAs were altered in both clones under N stress, while miR646 was regulated only in the N stress-insensitive clone (Nanlin 1388), and miR156, miR319 and miR393 in the N stress-sensitive clone (Nanlin 895). Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses also proved several clone-specific functions and pathways. These findings may be significant for understanding the genetic responses of Populus to N stress. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Continuous hydrothermal co-liquefaction of aspen wood and glycerol with water phase recirculation

    DEFF Research Database (Denmark)

    Pedersen, Thomas H.; Grigoras, Ionela F.; Hoffmann, Julia

    2016-01-01

    Hydrothermal liquefaction is a promising technology for the conversion of a wide range of bio-feedstock into a biocrude; a mixture of chemical compounds that holds the potential for a renewable production of chemicals and fuels. Most research in hydrothermal liquefaction is performed in batch type...... reactors, although a continuous and energy-efficient operation is paramount for such process to be feasible. In this work an experimental campaign in a continuous bench scale unit is presented. The campaign is based on glycerol-assisted hydrothermal liquefaction of aspen wood carried out with the presence...

  7. Genome Sequences of Populus tremula Chloroplast and Mitochondrion: Implications for Holistic Poplar Breeding.

    Directory of Open Access Journals (Sweden)

    Birgit Kersten

    Full Text Available Complete Populus genome sequences are available for the nucleus (P. trichocarpa; section Tacamahaca and for chloroplasts (seven species, but not for mitochondria. Here, we provide the complete genome sequences of the chloroplast and the mitochondrion for the clones P. tremula W52 and P. tremula x P. alba 717-1B4 (section Populus. The organization of the chloroplast genomes of both Populus clones is described. A phylogenetic tree constructed from all available complete chloroplast DNA sequences of Populus was not congruent with the assignment of the related species to different Populus sections. In total, 3,024 variable nucleotide positions were identified among all compared Populus chloroplast DNA sequences. The 5-prime part of the LSC from trnH to atpA showed the highest frequency of variations. The variable positions included 163 positions with SNPs allowing for differentiating the two clones with P. tremula chloroplast genomes (W52, 717-1B4 from the other seven Populus individuals. These potential P. tremula-specific SNPs were displayed as a whole-plastome barcode on the P. tremula W52 chloroplast DNA sequence. Three of these SNPs and one InDel in the trnH-psbA linker were successfully validated by Sanger sequencing in an extended set of Populus individuals. The complete mitochondrial genome sequence of P. tremula is the first in the family of Salicaceae. The mitochondrial genomes of the two clones are 783,442 bp (W52 and 783,513 bp (717-1B4 in size, structurally very similar and organized as single circles. DNA sequence regions with high similarity to the W52 chloroplast sequence account for about 2% of the W52 mitochondrial genome. The mean SNP frequency was found to be nearly six fold higher in the chloroplast than in the mitochondrial genome when comparing 717-1B4 with W52. The availability of the genomic information of all three DNA-containing cell organelles will allow a holistic approach in poplar molecular breeding in the future.

  8. Comparative genomic analysis of the WRKY III gene family in populus, grape, arabidopsis and rice.

    Science.gov (United States)

    Wang, Yiyi; Feng, Lin; Zhu, Yuxin; Li, Yuan; Yan, Hanwei; Xiang, Yan

    2015-09-08

    WRKY III genes have significant functions in regulating plant development and resistance. In plant, WRKY gene family has been studied in many species, however, there still lack a comprehensive analysis of WRKY III genes in the woody plant species poplar, three representative lineages of flowering plant species are incorporated in most analyses: Arabidopsis (a model plant for annual herbaceous dicots), grape (one model plant for perennial dicots) and Oryza sativa (a model plant for monocots). In this study, we identified 10, 6, 13 and 28 WRKY III genes in the genomes of Populus trichocarpa, grape (Vitis vinifera), Arabidopsis thaliana and rice (Oryza sativa), respectively. Phylogenetic analysis revealed that the WRKY III proteins could be divided into four clades. By microsynteny analysis, we found that the duplicated regions were more conserved between poplar and grape than Arabidopsis or rice. We dated their duplications by Ks analysis of Populus WRKY III genes and demonstrated that all the blocks were formed after the divergence of monocots and dicots. Strong purifying selection has played a key role in the maintenance of WRKY III genes in Populus. Tissue expression analysis of the WRKY III genes in Populus revealed that five were most highly expressed in the xylem. We also performed quantitative real-time reverse transcription PCR analysis of WRKY III genes in Populus treated with salicylic acid, abscisic acid and polyethylene glycol to explore their stress-related expression patterns. This study highlighted the duplication and diversification of the WRKY III gene family in Populus and provided a comprehensive analysis of this gene family in the Populus genome. Our results indicated that the majority of WRKY III genes of Populus was expanded by large-scale gene duplication. The expression pattern of PtrWRKYIII gene identified that these genes play important roles in the xylem during poplar growth and development, and may play crucial role in defense to drought

  9. Genome Sequences of Populus tremula Chloroplast and Mitochondrion: Implications for Holistic Poplar Breeding.

    Science.gov (United States)

    Kersten, Birgit; Faivre Rampant, Patricia; Mader, Malte; Le Paslier, Marie-Christine; Bounon, Rémi; Berard, Aurélie; Vettori, Cristina; Schroeder, Hilke; Leplé, Jean-Charles; Fladung, Matthias

    2016-01-01

    Complete Populus genome sequences are available for the nucleus (P. trichocarpa; section Tacamahaca) and for chloroplasts (seven species), but not for mitochondria. Here, we provide the complete genome sequences of the chloroplast and the mitochondrion for the clones P. tremula W52 and P. tremula x P. alba 717-1B4 (section Populus). The organization of the chloroplast genomes of both Populus clones is described. A phylogenetic tree constructed from all available complete chloroplast DNA sequences of Populus was not congruent with the assignment of the related species to different Populus sections. In total, 3,024 variable nucleotide positions were identified among all compared Populus chloroplast DNA sequences. The 5-prime part of the LSC from trnH to atpA showed the highest frequency of variations. The variable positions included 163 positions with SNPs allowing for differentiating the two clones with P. tremula chloroplast genomes (W52, 717-1B4) from the other seven Populus individuals. These potential P. tremula-specific SNPs were displayed as a whole-plastome barcode on the P. tremula W52 chloroplast DNA sequence. Three of these SNPs and one InDel in the trnH-psbA linker were successfully validated by Sanger sequencing in an extended set of Populus individuals. The complete mitochondrial genome sequence of P. tremula is the first in the family of Salicaceae. The mitochondrial genomes of the two clones are 783,442 bp (W52) and 783,513 bp (717-1B4) in size, structurally very similar and organized as single circles. DNA sequence regions with high similarity to the W52 chloroplast sequence account for about 2% of the W52 mitochondrial genome. The mean SNP frequency was found to be nearly six fold higher in the chloroplast than in the mitochondrial genome when comparing 717-1B4 with W52. The availability of the genomic information of all three DNA-containing cell organelles will allow a holistic approach in poplar molecular breeding in the future.

  10. Soil plant interactions of Populus alba in contrasting environments.

    Science.gov (United States)

    Ciadamidaro, Lisa; Madejón, Engracia; Robinson, Brett; Madejón, Paula

    2014-01-01

    The effects of the Populus alba tree on different biochemical soil properties, growing in a contaminated area, were studied for two years under field conditions. Two types of trace element contaminated soils were studied: a neutral contaminated soil (NC) and an acid contaminated soil (AC). One neutral non-contaminated area was studied as control. Soil samples were collected at depths of 0-20 cm and 20-40 cm. Leaves and litter samples were analysed. The addition of organic matter, through root exudates and litter, contributed to an increase in soil pH, especially in acid soil. Microbial Biomass Carbon (MBC) was significantly increased by the presence of the trees in all studied areas, especially in the upper soil layer. Similar results were also observed for protease activity. Both MBC and Protease activity were more sensitive to contamination than β-glucosidase activity. These changes resulted in a decrease of available trace element concentrations in soil and in an improvement of soil quality after a 2-year study. The total concentration of Cd and Zn in soil did not increase over time due to litter deposition. Analysis of P. alba leaves did not show a significant nutritional imbalance and trace element concentrations were normal for plants, except for Cd and Zn. These results indicate that P. alba is suitable for the improvement of soil quality in riparian contaminated areas. However, due to the high Cd and Zn concentrations in leaves, further monitoring of this area is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Examining Mechanisms of Methane Transport in Populus trichocarpa

    Science.gov (United States)

    Rosenstiel, T. N.; Kutschera, E.; Rice, A. L.; Kahlil, A.

    2016-12-01

    Although the dynamics of methane (CH4 ) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global CH4 emission and the mechanisms of tree transport are relatively unknown. CH4 emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to CH4 enriched water and whole-canopy emissions of CH4 were measured. The average flux for 34 trials (at temperatures ranging from 17 to 25 C) was 2.8 ± 2.2 μg CH4 min-1(whole canopy). Overall intra-tree CH4 flux increased with temperature. Compared to the isotopic composition of root water CH4 , δ13 C values were depleted for canopy CH4 where the warmest temperatures (24.4-28.7 C) resulted in an epsilon of 2.8 ± 4.7‰; midrange temperatures (20.4- 22.1 C) produced an epsilon of 7.5 ±3.1 ‰; and the coolest temperatures examined (16.0-19.1 C) produced an epsilon of 10.2 ± 3.2 ‰. From these results it is concluded that there msy br multiple transport processes at work in CH4 transport through trees and the dominance of these processes clearly changes with temperature. Overall, the intra-tree transport mechanisms that dominates at lower temperatures and during lower fluxes results in a larger overall fractionation, while the transport mechanisms that prevail at higher temperatures and higher and higher overall fluxes produces a smaller isotopic fractionation. These findings, as well as additional lab and field-based measures will be presented. Finally, the implications of possibly distinct forms of CH4 gas transport within trees, and it's impact on understanding of biogeochemical processes, will be discussed.

  12. Molecular evolution of synonymous codon usage in Populus

    Directory of Open Access Journals (Sweden)

    Ingvarsson Pär K

    2008-11-01

    Full Text Available Abstract Background Evolution of synonymous codon usage is thought to be determined by a balance between mutation, genetic drift and natural selection on translational efficiency. However, natural selection on codon usage is considered to be a weak evolutionary force and selection on codon usage is expected to be strongest in species with large effective population sizes. Results I examined the evolution of synonymous codons using EST data from five species of Populus. Data on relative synonymous codon usage in genes with high and low gene expression were used to identify 25 codons from 18 different amino acids that were deemed to be preferred codons across all five species. All five species show significant correlations between codon bias and gene expression, independent of base composition, thus indicating that translational selection has shaped synonymous codon usage. Using a set of 158 orthologous genes I detected an excess of unpreferred to preferred (U → P mutations in two lineages, P. tremula and P. deltoides. Maximum likelihood estimates of the strength of selection acting on synonymous codons was also significantly greater than zero in P. tremula, with the ML estimate of 4Nes = 0.720. Conclusion The data is consistent with weak selection on preferred codons in all five species. There is also evidence suggesting that selection on synonymous codons has increased in P. tremula. Although the reasons for the increase in selection on codon usage in the P. tremula lineage are not clear, one possible explanation is an increase in the effective population size in P. tremula.

  13. Establishment of Populus deltoides under simulated alluvial groundwater declines

    Science.gov (United States)

    Segelquist, Charles A.; Scott, Michael L.; Auble, Gregor T.

    1993-01-01

    Establishment, growth, and survival of seedlings of Populus deltoides subsp. monilifera (plains cottonwood) were examined in an experimental facility simulating five rates of declining alluvial groundwater. The treatments were permanent saturation, drawdown rates of 0.4, 0.7, 2.9 cm/d and immediate drainage. The experiment was conducted outdoors in planters near Fort Collins, Colorado. Seedling survival was highest under the two slowest drawdown rates and declined significantly with faster drawdown rates. The highest growth rate was associated with the drawdown rate of 0.4 cm/d, in which mean shoot height was 2.4 cm and mean root length was 39 am 98 days after planting. Growth of shoots and roots was reduced both by saturated conditions and by the more rapid drawdown rates of 0.7 and 2.9 cm/d. No establishment was observed in the immediate drawdown treatment. Whereas maximum biomass accumulation is associated with the most gradual drawdown or saturated conditions, seedling establishing naturally under such conditions are also most likely to be removed by ice or subsequent flooding. Seedlings establishing in higher topographic positions, in contrast, are subject to increased mortality and reduced shoot growth, resulting from reduced soil moisture. Rapid root extension following establishment allows P. deltoides seedlings to grow across a wide range of groundwater drawdown rates, and thus a variety of positions across a gradient of riparian soil moisture. Our results indicate that in coarse alluvial sands of low fertility, 47% of germinating P. deltoides seeds were able to survive in associated with a drawdown rate of 2.9 cm/d and a final water table depth of 80 cm.

  14. Fine root dynamics in a developing Populus deltoides plantation.

    Science.gov (United States)

    Kern, Christel C; Friend, Alexander L; Johnson, Jane M-F; Coleman, Mark D

    2004-06-01

    A closely spaced (1 x 1 m) cottonwood (Populus deltoides Bartr.) plantation was established to evaluate the effects of nutrient availability on fine root dynamics. Slow-release fertilizer (17:6:12 N,P,K plus micronutrients) was applied to 225-m(2) plots at 0, 50, 100 and 200 kg N ha(-1), and plots were monitored for two growing seasons. Fine root production, mortality, live root standing crop and life span were analyzed based on monthly minirhizotron observations. Fine root biomass was measured in soil cores. Fine root dynamics were controlled more by temporal, depth and root diameter factors than by fertilization. Cumulative fine root production and mortality showed strong seasonal patterns; production was greatest in the middle of the growing season and mortality was greatest after the growing season. Small diameter roots at shallow soil depths cycled more rapidly than larger or deeper roots. The strongest treatment effects were found in the most rapidly cycling roots. The standing crop of live roots increased with fertilizer treatment according to both minirhizotron and soil coring methods. However, production and mortality had unique treatment response patterns. Although cumulative mortality decreased in response to increased fertilization, cumulative production was intermediate at 0 kg N ha(-1), lowest with 50 kg N ha (-1), and highest with 200 kg N ha(-1). Aboveground growth responded positively to fertilization up to an application rate of 50 kg N ha(-1), but no further increases in growth were observed despite a threefold increase in application rate. Median fine root life span varied from 307 to over 700 days and increased with depth, diameter and nutrient availability.

  15. Sex-specific responses of Populus deltoides to defoliation

    Directory of Open Access Journals (Sweden)

    Li Shuxin

    2017-12-01

    Full Text Available There has been an increasing interest in understanding the differential effects of sexual dimorphism on plant stress responses. However, there is no clear pattern in the responses of the sexes to defoliation. In this study, the effects of different severity of artificial defoliation on biomass production, total nonstructural carbohydrate (NSC concentration, and photosynthetic rate (PN of male and female Populus deltoides were examined. We used half and full defoliation to observe the differences between the sexes in three harvest dates (1 week, 4 weeks, and 8 weeks after treatments. We hypothesized that female and male P. deltoides compared with an undefoliated control would have compensatory growth in response to defoliation treatments. Results showed that half and full defoliation reduced the growth of both sexes. Following half defoliation, root growth was reduced, especially in males, at T2 (4 weeks after defoliation and T3 (8 weeks after defoliation, while males showed an increase in height increment under the half defoliation compared with the nondefoliation treatments. By contrast, females were more negatively affected by defoliation than males in terms of biomass after 8 weeks. One week after defoliation, PN increased significantly in females and males under half defoliation (+30%, +32%, respectively and full defoliation (+58%, +56%, respectively. However, 8 weeks after defoliation, there was little difference in PN between defoliated and undefoliated female cuttings. Increases in stomatal conductance (gs and leaf nitrogen were observed under fully defoliated female and male cuttings. Moreover, males had less NSC concentrations following half defoliation compared with females. Our results indicate that leaf compensatory growth in male cuttings of P. deltoides was maintained by obtaining greater photosynthetic capacity, higher leaf nitrogen, and lower NSC concentration following half and full defoliation. Our results highlight that

  16. Effects of ozone on stomatal responses to environmental parameters (blue light, red light, CO2 and vapour pressure deficit) in three Populus deltoides × Populus nigra genotypes.

    Science.gov (United States)

    Dumont, Jennifer; Spicher, Fabien; Montpied, Pierre; Dizengremel, Pierre; Jolivet, Yves; Le Thiec, Didier

    2013-02-01

    The effect of ozone (O(3)) on stomatal regulation was studied in three Euramerican poplar genotypes (Populus deltoides × Populus nigra: Carpaccio, Cima and Robusta). The impact of O(3) on stomatal conductance responses to variations in blue light, red light, CO(2) concentration and vapour pressure deficit (VPD) was studied. Upon O(3) exposure, a sluggish response of stomatal movements was observed, characterized by slower reactions to increases in blue light intensity, CO(2) concentration and VPD, and lower amplitude of the response to variations in light intensity. That sluggish response should be taken into account in stomatal conductance models for phytotoxic ozone dose (POD(Y)) calculations. The speed of the response to variations in environmental parameters appears as a determining factor of genotype-related sensitivity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Simulated control in Aspen Dynamics for the production of limonene epoxide at pilot scale

    Directory of Open Access Journals (Sweden)

    Yeison Agudelo Arenas

    2016-12-01

    Full Text Available In this contribution is reported the study and analysis of the control system (simulated for the process of obtaining limonene epoxide. The modelling of the process at pilot scale was implemented in the software Aspen Plus from literature reports. Aspen Dynamics was used for the study of the process control. The model allows observing the behavior of the variables of interest in the process such as outflows from the distillation tower, heat duty, operating temperaturas and purity of the final product (limonene epoxide. The performance of the controllers (level, flow and temperature was evaluated by simulating disturbances (+30% in the feedstream to the process. Sensitivity analysis and preliminary design specifications allow to conclude that according to the simulations it is possible to obtain limonene epoxide (97,5% w/w with this system. The results of this work can be used for more detailed studies of the system, including experimental study designs that help to determine the operating point for the process variables which increase limonene epoxide production.

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

    Directory of Open Access Journals (Sweden)

    Sergey Yu. Popov

    2017-05-01

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

  19. Severe obesity: a growing health concern A.S.P.E.N. should not ignore.

    Science.gov (United States)

    Shikora, Scott A

    2005-01-01

    The definition of malnutrition in the published standards of the American Society of Parenteral and Enteral Nutrition (A.S.P.E.N.) is any derangement in the normal nutrition status and includes overnutrition, commonly referred to as obesity. The incidence of obesity is increasing and reaching epidemic proportions in the United States and even worldwide. This has significant financial impact as our society spends billions of dollars on fad diets, commercial weight-loss programs, nutrition and dietary supplements, prescription and over-the-counter medications, and health clubs. Another approximately dollars 100 billion are spent to treat the medical consequences of obesity. Currently, for those patients with intractable morbid obesity, defined as having a body mass index >40 kg/m2, surgery offers the only option for achieving meaningful and sustainable weight loss. The resultant weight loss dramatically improves health and decreases the cost of health care for these patients. Years of refinement in technology and the introduction of safer and less invasive procedures have dramatically reduced the short-term morbidities and long-term metabolic consequences of these procedures. This address will review the field of weight loss (bariatric) surgery and will offer a compelling request for A.S.P.E.N. to include obesity in its fabric.

  20. Development of an ASPEN PLUS physical property database for biofuels components

    Energy Technology Data Exchange (ETDEWEB)

    Wooley, R.J.; Putsche, V.

    1996-04-01

    Physical property data for many of the key components used in the simulation for the ethanol from lignocellulose process are not available in the standard ASPEN PLUS property databases. Indeed, many of the properties necessary to successfully simulate this process are not available anywhere. In addition, inputting the available properties into each simulation is awkward and tedious, and mistakes can be easily introduced when a long list of physical property equation parameters is entered. Therefore, one must evaluate the literature, estimate properties where necessary, and determine a set of consistent physical properties for all components of interest. The components must then be entered into an in-house NREL ASPEN PLUS database so they can be called on without being retyped into each specific simulation. The first phase of this work is complete. A complete set of properties for the currently identifiable important compounds in the ethanol process is attached. With this as the starting base the authors can continue to search for and evaluate new properties or have properties measured in the laboratory and update the central database.

  1. Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site

    Science.gov (United States)

    Rakesh Minocha; Stephanie Long; Subhash Minocha; Paula Marquardt; Neil Nelson; Mark. Kubiske

    2010-01-01

    This study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA). Since 1998, 12 experimental rings planted in 1997 underwent four different treatments: control; elevated CO2 (560 ppm); elevated O3 (1.5X ambient) and elevated CO2 (560 ppm) + O...

  2. The Rise of Netpolitik: How the Internet Is Changing International Politics and Diplomacy. A Report of the Annual Aspen Institute Roundtable on Information Technology (11th, Aspen, Colorado, August 1-4, 2002).

    Science.gov (United States)

    Bollier, David

    This document is an interpretive synthesis of the discussion at a conference sponsored by the Aspen Institute that sought to develop new ways to understand how the Internet is changing the powers of the nation-state, the conduct of international relations, and the definitions of nation security. This report examines how the Internet and other…

  3. Seedling competition between native Populus deltoides (Salicaceae) and exotic Tamarix ramosissima (Tamaricaceae) across water regimes and substrate types.

    Science.gov (United States)

    Sher, Anna A; Marshall, Diane L

    2003-03-01

    Populus deltoides subsp. wislizinii (Salicaceae), a cottonwood native to the Middle Rio Grande of New Mexico, must potentially compete against exotic Tamarix ramosissima (Tamaricaceae) during establishment after flooding. We investigated competitive interactions between seedlings of Tamarix and Populus in two substrates representing field textures and declining (i.e., draw-down) or stagnant water tables. The experiment was performed using a full-additive series design and interpreted with response surface models for each species. As reflected in both aboveground mass and height, Populus suppressed aboveground growth of Tamarix across all treatments, whereas competitive effects of Tamarix against Populus could only be seen at low Populus densities. Clay substrates with draw-down stimulated the greatest growth and created the most intense competitive environment for both species. Tamarix was competitively suppressed in every substrate tested, with the weakest response in sand with no draw-down, where growth of Populus was poorest. These results suggest that stream flow management that promotes Populus establishment could also aid in controlling Tamarix invasion across a range of substrates.

  4. Response to drought and salt stress in leaves of poplar (Populus alba × Populus glandulosa): expression profiling by oligonucleotide microarray analysis.

    Science.gov (United States)

    Yoon, Seo-Kyung; Park, Eung-Jun; Choi, Young-Im; Bae, Eun-Kyung; Kim, Joon-Hyeok; Park, So-Young; Kang, Kyu-Suk; Lee, Hyoshin

    2014-11-01

    Drought and salt stresses are major environmental constraints on forest productivity. To identify genes responsible for stress tolerance, we conducted a genome-wide analysis in poplar (Populus alba × Populus glandulosa) leaves exposed to drought and salt (NaCl) stresses. We investigated gene expression at the mRNA level using oligonucleotide microarrays containing 44,718 genes from Populus trichocarpa. A total of 1604 and 1042 genes were up-regulated (≥2-fold; P value < 0.05) by drought and salt stresses, respectively, and 765 genes were up-regulated by both stresses. In addition, 2742 and 1685 genes were down-regulated by drought and salt stresses, respectively, and 1564 genes were down-regulated by both stresses. The large number of genes regulated by both stresses suggests that crosstalk occurs between the drought and salt stress responses. Most up-regulated genes were involved in functions such as subcellular localization, signal transduction, metabolism, and transcription. Among the up-regulated genes, we identified 47 signaling proteins, 65 transcription factors, and 43 abiotic stress-related genes. Several genes were modulated by only one of the two stresses. About 25% of the genes significantly regulated by these stresses are of unknown function, suggesting that poplar may provide an opportunity to discover novel stress-related genes. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  5. Dense genetic linkage maps of three Populus species (Populus deltoides, P. nigra and P. trichocarpa) based on AFLP and microsatellite markers.

    Science.gov (United States)

    Cervera, M T; Storme, V; Ivens, B; Gusmão, J; Liu, B H; Hostyn, V; Van Slycken, J; Van Montagu, M; Boerjan, W

    2001-06-01

    Populus deltoides, P. nigra, and P. trichocarpa are the most important species for poplar breeding programs worldwide. In addition, Populus has become a model for fundamental research on trees. Linkage maps were constructed for these three species by analyzing progeny of two controlled crosses sharing the same female parent, Populus deltoides cv. S9-2 x P. nigra cv. Ghoy and P. deltoides cv. S9-2 x P. trichocarpa cv. V24. The two-way pseudotestcross mapping strategy was used to construct the maps. Amplified fragment length polymorphism (AFLP) markers that segregated 1:1 were used to form the four parental maps. Microsatellites and sequence-tagged sites were used to align homoeologous groups between the maps and to merge linkage groups within the individual maps. Linkage analysis and alignment of the homoeologous groups resulted in 566 markers distributed over 19 groups for P. deltoides covering 86% of the genome, 339 markers distributed over 19 groups for P. trichocarpa covering 73%, and 369 markers distributed over 28 groups for P. nigra covering 61%. Several tests for randomness showed that the AFLP markers were randomly distributed over the genome.

  6. Surface fluxes and water balance of spatially varying vegetation within a small mountainous headwater catchment

    Directory of Open Access Journals (Sweden)

    G. N. Flerchinger

    2010-06-01

    Full Text Available Precipitation variability and complex topography often create a mosaic of vegetation communities in mountainous headwater catchments, creating a challenge for measuring and interpreting energy and mass fluxes. Understanding the role of these communities in modulating energy, water and carbon fluxes is critical to quantifying the variability in energy, carbon, and water balances across landscapes. The focus of this paper was: (1 to demonstrate the utility of eddy covariance (EC systems in estimating the evapotranspiration component of the water balance of complex headwater mountain catchments; and (2 to compare and contrast the seasonal surface energy and carbon fluxes across a headwater catchment characterized by large variability in precipitation and vegetation cover. Eddy covariance systems were used to measure surface fluxes over sagebrush (Artemesia arbuscula and Artemesia tridentada vaseyana, aspen (Populus tremuloides and the understory of grasses and forbs beneath the aspen canopy. Peak leaf area index of the sagebrush, aspen, and aspen understory was 0.77, 1.35, and 1.20, respectively. The sagebrush and aspen canopies were subject to similar meteorological forces, while the understory of the aspen was sheltered from the wind. Missing periods of measured data were common and made it necessary to extrapolate measured fluxes to the missing periods using a combination of measured and simulated data. Estimated cumulative evapotranspiratation from the sagebrush, aspen trees, and aspen understory were 384 mm, 314 mm and 185 mm. A water balance of the catchment indicated that of the 699 mm of areal average precipitation, 421 mm was lost to evapotranspiration, and 254 mm of streamflow was measured from the catchment; water balance closure for the catchment was within 22 mm. Fluxes of latent heat and carbon for all sites were minimal through the winter. Growing season fluxes of latent heat and carbon were consistently higher

  7. Litter Quality of Populus Species as Affected by Free-Air CO2

    NARCIS (Netherlands)

    Vermue, E.; Buurman, P.; Hoosbeek, M.R.

    2009-01-01

    The effect of elevated CO2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM) was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter

  8. Postglacial migration of Populus nigra L.: lessons learnt from chloroplast DNA

    NARCIS (Netherlands)

    Cottrell, J.E.; Krystufek, V.; Tabbener, H.E.; Milner, A.D.; Connolly, T.; Sing, L.; Fluch, S.; Burg, K.; Lefèvre, F.; Achard, P.; Bordács, S.; Gebhardt, K.; Vornam, B.; Smulders, M.J.M.; Vanden Broeck, A.H.; Slycken, Van J.; Storme, V.; Boerjan, W.; Castiglione, S.; Fossati, T.; Alba, N.; Agúndez, D.; Maestro, C.; Notivol, E.; Bovenschen, J.; Dam, van B.C.

    2005-01-01

    Eleven laboratories have collaborated to study chloroplast DNA (cpDNA) variation in black poplar (Populus nigra L.) across Europe in order to improve our understanding of the location of glacial refugia and the subsequent postglacial routes of recolonisation. A common analysis based on the

  9. Constitutively elevated salicylic acid levels alter photosynthesis and oxidative state but not growth in transgenic populus.

    Science.gov (United States)

    Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O; Nyamdari, Batbayar; Wilson, Mark C; Frost, Christopher J; Chen, Han-Yi; Babst, Benjamin A; Harding, Scott A; Tsai, Chung-Jui

    2013-07-01

    Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained.

  10. Differential interspecific incompatibility among Populus hybrids in sections Aigeiros Duby and Tacamahaca Spach

    Science.gov (United States)

    Assiti A. Mahama; Richard B. Hall; Ronald S. Zalesny

    2011-01-01

    In our previous Populus breeding, compatible crosses between P. maximowiczii A. Henry and P. deltoides Bartr. ex Marsh corroborated the potential of interspecific hybrids, despite low seed set. Our current objective was to test the range of incompatibility among intraspecific and interspecific crosses using...

  11. Chloride and sodium uptake potential over an entire rotation of Populus irrigated with landfill leachate

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny

    2009-01-01

    There is a need for information about the response of Populus genotypes to repeated application of high-salinity water and nutrient sources throughout an entire rotation. We have combined establishment biomass and uptake data with mid- and full-rotation growth data to project potential chloride (Cl−) and sodium (Na...

  12. Intercontinental divergence in the Populus-associated ectomycorrhizal fungus, Tricholoma populinum

    Science.gov (United States)

    L.C. Grubisha; N. Levsen; M.S. Olson; D.L. Taylor

    2012-01-01

    The ectomycorrhizal fungus Tricholoma populinum is host-specific with Populus species. T. populinum has wind-dispersed progagules and may be capable of long-distance dispersal. In this study, we tested the hypothesis of a panmictic population between Scandinavia and North America. DNA sequences from five...

  13. Characterization of Dof Transcription Factors and Their Responses to Osmotic Stress in Poplar (Populus trichocarpa).

    Science.gov (United States)

    Wang, Han; Zhao, Shicheng; Gao, Yuchi; Yang, Jingli

    2017-01-01

    The DNA-binding One Zinc Finger (Dof) genes are ubiquitous in many plant species and are especial transcription regulators that participate in plant growth, development and various procedures, including biotic and abiotic stress reactions. In this study, we identified 41 PtrDof members from Populus trichocarpa genomes and classified them into four groups. The conserved motifs and gene structures of some PtrDof genes belonging to the same subgroup were almost the same. The 41 PtrDof genes were dispersed on 18 of the 19 Populus chromosomes. Many key stress- or phytohormone-related cis-elements were discovered in the PtrDof gene promoter regions. Consequently, we undertook expression profiling of the PtrDof genes in leaves and roots in response to osmotic stress and abscisic acid. A total of seven genes (PtrDof14, 16, 25, 27, 28, 37 and 39) in the Populus Dof gene family were consistently upregulated at point in all time in the leaves and roots under osmotic and abscisic acid (ABA) stress. We observed that 12 PtrDof genes could be targeted by 15 miRNAs. Moreover, we mapped the cleavage site in PtrDof30 using the 5'RLM-RACE. The results showed that PtrDofs may have a role in resistance to abiotic stress in Populus trichocarpa.

  14. The response of Populus spp. to cadmium stress: chemical, morphological and proteomics study.

    Science.gov (United States)

    Marmiroli, Marta; Imperiale, Davide; Maestri, Elena; Marmiroli, Nelson

    2013-10-01

    Poplar (Populus) species are seen as candidates for removing heavy metal contamination from polluted soil. A bottom-up multidisciplinary approach was utilized to compare the performances of clones 58-861 and Poli (Populus nigra) and A4A, a Populus nigra × Populus deltoides hybrid to Cd toxicity. Qualitative and quantitative differences in their tolerance to Cd exposure and the uptake, accumulation and translocation of Cd were noted following the hydroponic exposure of rooted cuttings to 20 μM CdSO₄ for either 48 h or 14 d. Cadmium was less toxic for the hybrid clone A4A as compared to Poli and 58-861. Cd uptake and root to shoot translocation were determined by AAS, and its compartmentation was analyzed using SEM/EDX. A comparative proteomic approach was utilized to identify changes in proteins expression according to dose and time of exposure. Toxicity to Cd mainly influenced proteins related to general defense, stress response and carbohydrate metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Influence of irrigation and fertilization on transpiration and hydraulic properties of Populus deltoides

    Science.gov (United States)

    Lisa J. Samuelson; Thomas A. Stokes; Mark D. Coleman

    2007-01-01

    Long-term hydraulic acclimation to resource availability was explored in 3-year-old Populus deltoides Bartr. ex Marsh. clones by examining transpiration. leaf-specific hydraulic conductance (GL), canopy stomatal conductance (Gs) and leaf to sapwood area ratio (AL:Asi)n response to irrigation (13 and 551 mm in addition to ambient precipitation) and...

  16. Genome-wide analysis of lectin receptor-like kinases in Populus.

    Science.gov (United States)

    Yang, Yongil; Labbé, Jessy; Muchero, Wellington; Yang, Xiaohan; Jawdy, Sara S; Kennedy, Megan; Johnson, Jenifer; Sreedasyam, Avinash; Schmutz, Jeremy; Tuskan, Gerald A; Chen, Jin-Gui

    2016-09-01

    Receptor-like kinases (RLKs) belong to a large protein family with over 600 members in Arabidopsis and over 1000 in rice. Among RLKs, the lectin receptor-like kinases (LecRLKs) possess a characteristic extracellular carbohydrate-binding lectin domain and play important roles in plant development and innate immunity. There are 75 and 173 LecRLKs in Arabidopsis and rice, respectively. However, little is known about LecRLKs in perennial woody plants. Here we report the genome-wide analysis of classification, domain architecture and expression of LecRLKs in the perennial woody model plant Populus. We found that the LecRLK family has expanded in Populus to a total of 231, including 180 G-type, 50 L-type and 1 C-type LecRLKs. Expansion of the Populus LecRLKs (PtLecRLKs) occurred partially through tandem duplication. Based on domain architecture and orientation features, we classified PtLecRLKs into eight different classes. RNA-seq-based transcriptomics analysis revealed diverse expression patterns of PtLecRLK genes among leaves, stems, roots, buds and reproductive tissues and organs. This study offers a comprehensive view of LecRLKs in the perennial woody model plant Populus and provides a foundation for functional characterization of this important family of receptor-like kinases.

  17. Bulked segregant analysis identifies molecular markers linked to Melampsora medusae resistance in Populus deltoides

    Science.gov (United States)

    G. M. Tabor; Thomas L. Kubisiak; N. B. Klopfenstein; R. B. Hall; Henry S. McNabb

    2000-01-01

    In the north central United States, leaf rust caused by Melampsora medusae is a major disease problem on Populus deltoides. In this study we identified molecular markers linked to a M. medusae resistance locus (Lrd1) that was segregating 1:1 within an intraspecific P. deltoides...

  18. Selecting and utilizing Populus and Salix for landfill covers: implications for leachate irrigation

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Edmund O. Bauer

    2007-01-01

    The success of using Populus and Salix for phytoremediation has prompted further use of leachate as a combination of irrigation and fertilization for the trees. A common protocol for such efforts has been to utilize a limited number of readily-available genotypes with decades of deployment in other applications, such as fiber or...

  19. Latitudinal variation in cold hardiness in introduced Tamarix and native Populus

    Science.gov (United States)

    Native woody plants often demonstrate inherited latitudinal variation in cold hardiness. How long does it take for such variation to evolve in introduced species? We compared cold hardiness in the native plains cottonwood (Populus deltoides subsp. monilifera) and the introduced saltcedar (Tamarix ra...

  20. Use of belowground growing degree days to predict rooting of dormant hardwood cuttings of Populus

    Science.gov (United States)

    R.S., Jr. Zalesny; E.O. Bauer; D.E. Riemenschneider

    2004-01-01

    Planting Populus cuttings based on calendar days neglects soil temperature extremes and does not promote rooting based on specific genotypes. Our objectives were to: 1) test the biological efficacy of a thermal index based on belowground growing degree days (GDD) across the growing period, 2) test for interactions between belowground GDD and clones,...

  1. RepPop: a database for repetitive elements in Populus trichocarpa

    Directory of Open Access Journals (Sweden)

    Xu Ying

    2009-01-01

    Full Text Available Abstract Background Populus trichocarpa is the first tree genome to be completed, and its whole genome is currently being assembled. No functional annotation about the repetitive elements in the Populus trichocarpa genome is currently available. Results We predicted 9,623 repetitive elements in the Populus trichocarpa genome, and assigned functions to 3,075 of them (31.95%. The 9,623 repetitive elements cover ~40% of the current (partially assembled genome. Among the 9,623 repetitive elements, 668 have copies only in the contigs that have not been assigned to one of the 19 chromosome while the rest all have copies in the partially assembled chromosomes. Conclusion All the predicted data are organized into an easy-to-use web-browsable database, RepPop. Various search capabilities are provided against the RepPop database. A Wiki system has been set up to facilitate functional annotation and curation of the repetitive elements by a community rather than just the database developer. The database RepPop will facilitate the assembling and functional characterization of the Populus trichocarpa genome.

  2. The Populus homeobox gene ARBORKNOX2 regulates cell differentiation during secondary growth

    Science.gov (United States)

    Juan Du; Shawn D. Mansfield; Andrew T. Groover

    2009-01-01

    The stem cells of the vascular cambium divide to produce daughter cells, which in turn divide before undergoing differentiation during the radial growth of woody stems. The genetic regulation of these developmental events is poorly understood, however. We report here the cloning and functional characterization of a Populus class-I KNOX...

  3. Influence of Populus Genotype on Gene Expression by the Wood Decay Fungus Phanerochaete chrysosporium

    Science.gov (United States)

    Jill Gaskell; Amber Marty; Michael Mozuch; Philip J. Kersten; Sandra Splinter Bondurant; Grzegorz Sabat; Ali Azarpira; John Ralph; Oleksandr Skyba; Shawn D. Mansfield; Robert A. Blanchette; Dan Cullen

    2014-01-01

    We examined gene expression patterns in the lignin-degrading fungus Phanerochaete chrysosporium when it colonizes hybrid poplar (Populus alba tremula) and syringyl (S)-rich transgenic derivatives. Acombination ofmicroarrays and liquid chromatography- tandem mass spectrometry (LC-MS/MS) allowed detection of a total of 9,959 transcripts and 793...

  4. Carbon allocation and nitrogen acquisition in a developing Populus deltoides plantation

    Science.gov (United States)

    Mark D. Coleman; Alexander L. Friend; Christel C. Kern

    2004-01-01

    We established Populus deltoides Bartr. stands differing in nitrogen (N) availability and tested if: (1) N-induced carbon (C) allocation could be explained by developmental allocation controls; and (2) N uptake per unit root mass, i.e., specific N-uptake rate, increased with N availability. Closely spaced (1 x 1 m) stands were treated with 50, 100...

  5. Expression of a SK2-type dehydrin gene from Populus euphratica in ...

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... A dehydrin gene, isolated from cDNA library established from the root of Populus euphratica, was ... Dehydrins are group II (D-11 family) of the late ... of these genes to investigate whether it would enhance drought tolerance in transgenic tree. In this paper, we isolated one SK2-typed dehydrin gene.

  6. Drought effects on leaf abscission and leaf production in Populus clones

    Science.gov (United States)

    Stephen G. Pallardy; Julie L. Rhoads

    1997-01-01

    Leaf abscission and foliation responses to water stress were studied in potted plants of five Populus clones grown in a greenhouse. As predawn leaf water potential (Ψ1) fell to -3 MPa, drought-induced leaf abscission increased progressively to 30% for data pooled across clones. As predawn Ψ1...

  7. Environmental Influences on Wood Chemistry and Density of Populus and Loblolly Pine

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, G.A.

    2006-08-11

    The objectives of the study are to: (1) determine the degree to which physical and chemical wood properties vary in association with environmental and silvicultural practices in Populus and loblolly pine and (2) develop and verify species-specific empirical models in an effort to create a framework for understanding environmental influences on wood quality.

  8. Gibberellin-associated cisgenes modify growth, stature and wood properties in Populus

    Science.gov (United States)

    We studied the effects on plant growth from insertion of five cisgenes involved in gibberellic acid metabolism or signaling. We cloned intact genomic copies of GA20ox7, GA2ox2, RGL1_1, RGL1_2, and GAI1 genes from the genome sequenced Populus trichocarpa clone Nisqually-1, transformed them into Popul...

  9. Evaluation of Populus and Salix continuously irrigated with landfill leachate II. Soils and early tree development

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Edmund O. Bauer

    2007-01-01

    Soil contaminant levels and early tree growth data are helpful for assessing phytoremediation systems. Populus (DN17, DN182, DN34, NM2, and NM6) and Salix (94003, 94012, S287, S566, and SX61) genotypes were irrigated with landfill leachate or municipal water and tested for differences in 1) element concentrations (P, K, Ca, Mg, S,...

  10. Evaluation of Populus and Salix continuously irrigated with landfill leachate I. Genotype-specific elemental phytoremediation

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Edmund O. Bauer

    2007-01-01

    There is a need for the identification and selection of specific tree genotypes that can sequester elements from contaminated soils, with elevated rates of uptake. We irrigated Populus (DN17, DN182, DN34, NM2, NM6) and Salix (94003, 94012, S287, S566, SX61) genotypes planted in large soil-filled containers with landfill leachate or...

  11. Identification of quantitative trait loci and candidate genes for cadmium tolerance in Populus

    Energy Technology Data Exchange (ETDEWEB)

    Induri, Brahma R [West Virginia University; Ellis, Danielle R [West Virginia University; Slavov, Goncho T. [West Virginia University; Yin, Tongming [ORNL; Zhang, Xinye [ORNL; Tuskan, Gerald A [ORNL; DiFazio, Steven P [West Virginia University

    2012-01-01

    Understanding genetic variation for the response of Populus to heavy metals like cadmium (Cd) is an important step in elucidating the underlying mechanisms of tolerance. In this study, a pseudo-backcross pedigree of Populus trichocarpa Torr. & Gray and Populus deltoides Bart. was characterized for growth and performance traits after Cd exposure. A total of 16 quantitative trait loci (QTL) at logarithm of odds (LOD) ratio 2.5 were detected for total dry weight, its components and root volume. Major QTL for Cd responses were mapped to two different linkage groups and the relative allelic effects were in opposing directions on the two chromosomes, suggesting differential mechanisms at these two loci. The phenotypic variance explained by Cd QTL ranged from 5.9 to 11.6% and averaged 8.2% across all QTL. A whole-genome microarray study led to the identification of nine Cd-responsive genes from these QTL. Promising candidates for Cd tolerance include an NHL repeat membrane-spanning protein, a metal transporter and a putative transcription factor. Additional candidates in the QTL intervals include a putative homolog of a glutamate cysteine ligase, and a glutathione-S-transferase. Functional characterization of these candidate genes should enhance our understanding of Cd metabolism and transport and phytoremediation capabilities of Populus.

  12. Avian use of successional cottonwood (Populus deltoides) woodlands along the middle Missouri River

    Science.gov (United States)

    Mark A. Rumble; John E. Gobeille

    2004-01-01

    Cottonwood (Populus deltoides) woodlands are important habitats for birds. Yet, little is known of the relations between bird habitat and succession in these woodlands. We studied the bird community in cottonwood woodlands from early to late seral stages along the Missouri River in central South Dakota from 1990 to 1992 to describe quantitative...

  13. Molecular genetic analysis of black poplar (Populus nigra L.) along Dutch rivers

    NARCIS (Netherlands)

    Arens, P.; Coops, H.; Jansen, J.; Vosman, B.

    1998-01-01

    The genetic structure of remaining black poplar (Populus nigra) trees on the banks of the Dutch Rhine branches was investigated using the AFLP technique. In total, 143 trees, including one P. deltoides and some P. x euramericana, were analysed using six AFLP primer combinations which generated 319

  14. Anatomy and dry weight yields of two Populus clones grown under intensive culture.

    Science.gov (United States)

    John B. Crist; David H. Dawson

    1975-01-01

    Two Populus clones grown for short rotations at three dense planting spacings produced some extremely high yields of material of acceptable quality. However, variation in yields and quality illustrates that selection of genetic material and the cultured regime under which a species is growth are significant factors that must be determined in maximum-yield systems....

  15. Cryopreservation of Populus trichocarpa and Salix using dormant buds with recovery by grafting or direct rooting

    Science.gov (United States)

    Populus trichocarpa and Salix can be successfully cryopreserved by using dormant scions as the source explants. These scions (either at their original moisture content of 48 to 60% or dried to 30%) were slowly cooled to –35 degree Celsius, transferred to the vapor phase of liquid nitrogen (LNV,-160...

  16. Genome structure and emerging evidence of an incipient sex chromosome in Populus

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Tongming [ORNL; DiFazio, Stephen P [West Virginia University; Gunter, Lee E [ORNL; Zhang, Xinye [ORNL; Sewell, Mitchell [ORNL; Woolbright, Dr. Scott [North Arizona University; Allan, Dr. Gery [North Arizona University; Kelleher, Colin [University of British Columbia, Vancouver; Douglas, Carl [University of British Columbia, Vancouver; Wang, Prof. Mingxiu [Nanjing Forestry University, China; Tuskan, Gerald A [ORNL

    2008-01-01

    The genus Populus consists of dioecious woody species with largely unknown genetic mechanisms for gender determination. We have discovered genetic and genomic features in the peritelomeric region of chromosome XIX that suggest this region of the Populus genome is in the process of developing characteristics of a sex chromosome. We have identified a gender-associated locus that consistently maps to this region. Furthermore, comparison of genetic maps across multiple Populus families reveals consistently distorted segregation within this region. We have intensively characterized this region using an F1 interspecific cross involving the female genotype that was used for genome sequencing. This region shows suppressed recombination and high divergence between the alternate haplotypes, as revealed by dense map-based genome assembly using microsatellite markers. The suppressed recombination, distorted segregation, and haplotype divergence were observed only for the maternal parent in this cross. Furthermore, the progeny of this cross showed a strongly male-biased sex ratio, in agreement with Haldane's rule that postulates that the heterogametic sex is more likely to be absent, rare, or sterile in interspecific crosses. Together, these results support the role of chromosome XIX in sex determination and suggest that sex determination in Populus occurs through a ZW system in which the female is the heterogametic gender.

  17. Recent advances in research of some pest problems of hybrid populus in Michigan and Wisconsin

    Science.gov (United States)

    Lincoln M. Moore; Louis F. Wilson

    1983-01-01

    Hybrid Populus clones were examined for impact from and resistance to attack from several insects and diseases. Cottonwood leaf beetle, poplar-and-willow borer, and Septoria canker were most injurious. The spotted poplar aphid and poplar-gall saperda, even when abundant, caused only minor impact. The tarnished plant bug, a newly identified pest of...

  18. Clonal variation in lateral and basal rooting of Populus irrigated with landfill leachate

    Science.gov (United States)

    R.S. Zalesny Jr.; J.A. Zalesny

    2011-01-01

    Successful establishment and productivity of Populus depends upon adventitious rooting from: 1) lateral roots that develop from either preformed or induced primordia and 2) basal roots that differentiate from callus at the base of the cutting in response to wounding. Information is needed for phytotechnologies about the degree to which ...

  19. Semi-Interpenetrating polymer network hydrogels based on aspen hemicellulose and chitosan: Effect of crosslinking sequence on hydrogel properties

    Science.gov (United States)

    Muzaffer Ahmet Karaaslan; Mandla A. Tshabalala; Gisela. Buschle-Diller

    2012-01-01

    Semi-interpenetrating network hydrogel films were prepared using hemicellulose and chemically crosslinked chitosan. Hemicellulose was extracted from aspen by using a novel alkaline treatment and characterized by HPSEC, and consisted of a mixture of high and low molecular weight polymeric fractions. HPLC analysis of the acid hydrolysate of the hemicellulose showed that...

  20. Assessment of aspen ecosystem vulnerability to climate change for the Uinta-Wasatch-Cache and Ashley National Forests, Utah

    Science.gov (United States)

    Janine Rice; Tim Bardsley; Pete Gomben; Dustin Bambrough; Stacey Weems; Allen Huber; Linda A. Joyce

    2017-01-01

    Aspen ecosystems are valued because they add biodiversity and ecological value to the landscape. They provide rich and productive habitats and increase aesthetic value. Climate change poses the risk of altering and disrupting these ecosystems, and it may worsen the effects of non-climate stressors. To provide scientific information for land managers facing the...

  1. Species richness has not increased after long-term protection from grazing on sagebrush, aspen and tall forb rangelands

    Science.gov (United States)

    W. A. Laycock; Dale Bartos; Keith Klement

    2001-01-01

    Recent conservation biology and environmental literature contains claims that livestock grazing has caused and continues to cause reduction in species diversity on Western rangelands, especially public rangelands. This paper present quantitative data on species richness (number of species) inside and outside 24 long-term exclosures; 8 exclosures in aspen vegetation in...

  2. Using aspen for artist stretcher frames: adding value through quality service, direct marketing, and careful material selection

    Science.gov (United States)

    Chris. Polson

    2001-01-01

    Aspen wood, when carefully selected and kiln dried, makes excellent stock for artist stretcher frames. Direct marketing techniques including the Internet and word of mouth give access to national markets, providing a more diverse and stable customer base for operations from a rural area. High-quality service, as shown by product performance and rapid order fulfillment...

  3. Aging in a long-lived clonal tree.

    Directory of Open Access Journals (Sweden)

    Dilara Ally

    2010-08-01

    Full Text Available From bacteria to multicellular animals, most organisms exhibit declines in survivorship or reproductive performance with increasing age ("senescence". Evidence for senescence in clonal plants, however, is scant. During asexual growth, we expect that somatic mutations, which negatively impact sexual fitness, should accumulate and contribute to senescence, especially among long-lived clonal plants. We tested whether older clones of Populus tremuloides (trembling aspen from natural stands in British Columbia exhibited significantly reduced reproductive performance. Coupling molecular-based estimates of clone age with male fertility data, we observed a significant decline in the average number of viable pollen grains per catkin per ramet with increasing clone age in trembling aspen. We found that mutations reduced relative male fertility in clonal aspen populations by about 5.8 x 10(-5 to 1.6 x 10(-3 per year, leading to an 8% reduction in the number of viable pollen grains, on average, among the clones studied. The probability that an aspen lineage ultimately goes extinct rises as its male sexual fitness declines, suggesting that even long-lived clonal organisms are vulnerable to senescence.

  4. Transcriptomic analysis of Clostridium thermocellum Populus hydrolysate-tolerant mutant strain shows increased cellular efficiency in response to Populus hydrolysate compared to the wild type strain.

    Science.gov (United States)

    Linville, Jessica L; Rodriguez, Miguel; Brown, Steven D; Mielenz, Jonathan R; Cox, Chris D

    2014-08-16

    The thermophilic, anaerobic bacterium, Clostridium thermocellum is a model organism for consolidated processing due to its efficient fermentation of cellulose. Constituents of dilute acid pretreatment hydrolysate are known to inhibit C. thermocellum and other microorganisms. To evaluate the biological impact of this type of hydrolysate, a transcriptomic analysis of growth in hydrolysate-containing medium was conducted on 17.5% v/v Populus hydrolysate-tolerant mutant (PM) and wild type (WT) strains of C. thermocellum. In two levels of Populus hydrolysate medium (0% and 10% v/v), the PM showed both gene specific increases and decreases of gene expression compared to the wild-type strain. The PM had increased expression of genes in energy production and conversion, and amino acid transport and metabolism in both standard and 10% v/v Populus hydrolysate media. In particular, expression of the histidine metabolism increased up to 100 fold. In contrast, the PM decreased gene expression in cell division and sporulation (standard medium only), cell defense mechanisms, cell envelope, cell motility, and cellulosome in both media. The PM downregulated inorganic ion transport and metabolism in standard medium but upregulated it in the hydrolysate media when compared to the WT. The WT differentially expressed 1072 genes in response to the hydrolysate medium which included increased transcription of cell defense mechanisms, cell motility, and cellulosome, and decreased expression in cell envelope, amino acid transport and metabolism, inorganic ion transport and metabolism, and lipid metabolism, while the PM only differentially expressed 92 genes. The PM tolerates up to 17.5% v/v Populus hydrolysate and growth in it elicited 489 genes with differential expression, which included increased expression in energy production and conversion, cellulosome production, and inorganic ion transport and metabolism and decreased expression in transcription and cell defense mechanisms. These

  5. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

    Science.gov (United States)

    Tian, Feng-Xia; Zang, Jian-Lei; Wang, Tan; Xie, Yu-Li; Zhang, Jin; Hu, Jian-Jun

    2015-01-01

    Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

  6. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

    Directory of Open Access Journals (Sweden)

    Feng-Xia Tian

    Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

  7. Identification of Quantitative Trait Loci (QTL) and Candidate Genes for Cadmium Tolerance in Populus

    Energy Technology Data Exchange (ETDEWEB)

    Induri, Brahma R [West Virginia University; Ellis, Danielle R [West Virginia University; Slavov, Gancho [West Virginia University; Yin, Tongming [ORNL; Muchero, Wellington [ORNL; Tuskan, Gerald A [ORNL; DiFazio, Stephen P [West Virginia University

    2012-01-01

    Knowledge of genetic variation in response of Populus to heavy metals like cadmium (Cd) is an important step in understanding the underlying mechanisms of tolerance. In this study, a pseudo-backcross pedigree of Populus trichocarpa and Populus deltoides was characterized for Cd exposure. The pedigree showed significant variation for Cd tolerance thus enabling the identification of relatively tolerant and susceptible genotypes for intensive characterization. A total of 16 QTLs at logarithm of odds (LOD) ratio > 2.5, were found to be associated with total dry weight, its components, and root volume. Four major QTLs for total dry weight were mapped to different linkage groups in control (LG III) and Cd conditions (LG XVI) and had opposite allelic effects on Cd tolerance, suggesting that these genomic regions were differentially controlled. The phenotypic variation explained by Cd QTL for all traits under study varied from 5.9% to 11.6% and averaged 8.2% across all QTL. Leaf Cd contents also showed significant variation suggesting the phytoextraction potential of Populus genotypes, though heritability of this trait was low (0.22). A whole-genome microarray study was conducted by using two genotypes with extreme responses for Cd tolerance in the above study and differentially expressed genes were identified. Candidate genes including CAD2 (CADMIUM SENSITIVE 2), HMA5 (HEAVY METAL ATPase5), ATGTST1 (Arabidopsis thaliana Glutathione S-Transferase1), ATGPX6 (Glutathione peroxidase 6), and ATMRP 14 (Arabidopsis thaliana Multidrug Resistance associated Protein 14) were identified from QTL intervals and microarray study. Functional characterization of these candidate genes could enhance phytoremediation capabilities of Populus.

  8. The Potential of Aspen Clonal Forestry in Alberta: Breeding Regions and Estimates of Genetic Gain from Selection

    Science.gov (United States)

    Gylander, Tim; Hamann, Andreas; Brouard, Jean S.; Thomas, Barb R.

    2012-01-01

    Background Aspen naturally grows in large, single-species, even-aged stands that regenerate clonally after fire disturbance. This offers an opportunity for an intensive clonal forestry system that closely emulates the natural life history of the species. In this paper, we assess the potential of genetic tree improvement and clonal deployment to enhance the productivity of aspen forests in Alberta. We further investigate geographic patterns of genetic variation in aspen and infer forest management strategies under uncertain future climates. Methodology/Principal Findings Genetic variation among 242 clones from Alberta was evaluated in 13 common garden trials after 5–8 growing seasons in the field. Broad-sense heritabilities for height and diameter at breast height (DBH) ranged from 0.36 to 0.64, allowing 5–15% genetic gains in height and 9–34% genetic gains in DBH. Geographic partitioning of genetic variance revealed predominant latitudinal genetic differentiation. We further observed that northward movement of clones almost always resulted in increased growth relative to local planting material, while southward movement had a strong opposite effect. Conclusion/Significance Aspen forests are an important natural resource in western Canada that is used for pulp and oriented strandboard production, accounting for ∼40% of the total forest harvest. Moderate to high broad-sense heritabilities in growth traits suggest good potential for a genetic tree improvement program with aspen. Significant productivity gains appear possible through clonal selection from existing trials. We propose two breeding regions for Alberta, and suggest that well-tested southern clones may be used in the northern breeding region, accounting for a general warming trend observed over the last several decades in Alberta. PMID:22957006

  9. Response Surface Methodology and Aspen Plus Integration for the Simulation of the Catalytic Steam Reforming of Ethanol

    Directory of Open Access Journals (Sweden)

    Bernay Cifuentes

    2017-01-01

    Full Text Available The steam reforming of ethanol (SRE on a bimetallic RhPt/CeO2 catalyst was evaluated by the integration of Response Surface Methodology (RSM and Aspen Plus (version 9.0, Aspen Tech, Burlington, MA, USA, 2016. First, the effect of the Rh–Pt weight ratio (1:0, 3:1, 1:1, 1:3, and 0:1 on the performance of SRE on RhPt/CeO2 was assessed between 400 to 700 °C with a stoichiometric steam/ethanol molar ratio of 3. RSM enabled modeling of the system and identification of a maximum of 4.2 mol H2/mol EtOH (700 °C with the Rh0.4Pt0.4/CeO2 catalyst. The mathematical models were integrated into Aspen Plus through Excel in order to simulate a process involving SRE, H2 purification, and electricity production in a fuel cell (FC. An energy sensitivity analysis of the process was performed in Aspen Plus, and the information obtained was used to generate new response surfaces. The response surfaces demonstrated that an increase in H2 production requires more energy consumption in the steam reforming of ethanol. However, increasing H2 production rebounds in more energy production in the fuel cell, which increases the overall efficiency of the system. The minimum H2 yield needed to make the system energetically sustainable was identified as 1.2 mol H2/mol EtOH. According to the results of the integration of RSM models into Aspen Plus, the system using Rh0.4Pt0.4/CeO2 can produce a maximum net energy of 742 kJ/mol H2, of which 40% could be converted into electricity in the FC (297 kJ/mol H2 produced. The remaining energy can be recovered as heat.

  10. The potential of aspen clonal forestry in Alberta: breeding regions and estimates of genetic gain from selection.

    Directory of Open Access Journals (Sweden)

    Tim Gylander

    Full Text Available BACKGROUND: Aspen naturally grows in large, single-species, even-aged stands that regenerate clonally after fire disturbance. This offers an opportunity for an intensive clonal forestry system that closely emulates the natural life history of the species. In this paper, we assess the potential of genetic tree improvement and clonal deployment to enhance the productivity of aspen forests in Alberta. We further investigate geographic patterns of genetic variation in aspen and infer forest management strategies under uncertain future climates. METHODOLOGY/PRINCIPAL FINDINGS: Genetic variation among 242 clones from Alberta was evaluated in 13 common garden trials after 5-8 growing seasons in the field. Broad-sense heritabilities for height and diameter at breast height (DBH ranged from 0.36 to 0.64, allowing 5-15% genetic gains in height and 9-34% genetic gains in DBH. Geographic partitioning of genetic variance revealed predominant latitudinal genetic differentiation. We further observed that northward movement of clones almost always resulted in increased growth relative to local planting material, while southward movement had a strong opposite effect. CONCLUSION/SIGNIFICANCE: Aspen forests are an important natural resource in western Canada that is used for pulp and oriented strandboard production, accounting for ~40% of the total forest harvest. Moderate to high broad-sense heritabilities in growth traits suggest good potential for a genetic tree improvement program with aspen. Significant productivity gains appear possible through clonal selection from existing trials. We propose two breeding regions for Alberta, and suggest that well-tested southern clones may be used in the northern breeding region, accounting for a general warming trend observed over the last several decades in Alberta.

  11. Altering carbon allocation in hybrid poplar (Populus alba × grandidentata) impacts cell wall growth and development

    National Research Council Canada - National Science Library

    Unda, Faride; Kim, Hoon; Hefer, Charles; Ralph, John; Mansfield, Shawn D

    ... s) that function as transport carbohydrates in the phloem, as storage compounds in sink tissues and as soluble metabolites that combat both abiotic and biotic stress in several plant species. Hybrid poplar (Populus alba × grandidentata...

  12. Modeling of the Sulfuric Acid and Sulfur Trioxide Decomposer using Aspen Plus

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong Un; Park, G. C. [Seoul National University, Seoul (Korea, Republic of); Kim, C. S.; Yoo, T. H.; Hong, S. D.; Kim, Y. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    A hydrogen production system using VHTR, which was combined with a Sulfur-Iodine (SI) thermochemical cycle, is a good candidate for massive hydrogen production. It is being investigated for Nuclear Hydrogen Development and Demonstration (NHDD) project in Korea Atomic Energy Research Institute. The SI thermo-chemical cycle is a good promise for the economical and eco-friendly hydrogen production. In SI cycle, the decomposition of a sulfuric acid is main concern for the material corrosion and mechanical stress on high temperature and pressure operation condition. KAERI has designed and constructed a small-scale gas loop that included sulfuric acid experimental facilities as a secondary loop. The main objectives of the loop are to monitor and validate the performances of NHDD component such as the Process Heat Exchanger (PHE) and sulfuric acid decomposer. In this paper, we discussed the results of the modeling of the sulfuric acid and sulfur trioxide decomposer using Aspen plus process simulator

  13. A simulation study of Solid Oxide fuel cell for IGCC power generation using Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Kim, Hyung Taek

    2010-01-01

    operating conditions and using diverse fuels. The SOFC stack model developed using the chemical process flow sheet simulator Aspen Plus which is of equilibrium type and is based on Gibbs free energy minimization. The SOFC model performs heat and mass balances and considers the ohmic, activation......The solid oxide fuel cell (SOFC) is a promising technology for electricity generation. Sulfur free syngas from the gas cleaning unit serves as a fuel for SOFC in IGFC (Integrated gasification Fuel cell) power plant. It converts the chemical energy of the fuel gas directly to electric energy...... and therefore, very high efficiencies can be achieved. The high operating temperature of the SOFC also provides excellent possibilities for cogeneration application. The outputs from SOFC can be utilized by HRSG which helps to drive steam generator. Recent developments in modeling techniques has resulted...

  14. Aspen Global Change Institute: 25 Years of Interdisciplinary Global Change Science

    Energy Technology Data Exchange (ETDEWEB)

    Meehl, Gerald A.; Moss, Richard

    2016-11-01

    Global environmental changes such as climate change result from the interaction of human and natural systems. Research to understand these changes and options for addressing them requires the physical, environmental, and social sciences, as well as engineering and other applied fields. In this essay, we describe how the Aspen Global Change Institute (AGCI) has provided leadership in global change science over the past 25 years—in particular how it has contributed to the integration of the natural and social sciences needed to research the drivers of change, Earth system response, natural and human system impacts, and options for risk management. We illustrate the ways the history of AGCI has been intertwined with the evolution of global change science as it has become an increasingly interdisciplinary endeavor.

  15. ASPEN plus modelling of air–steam gasification of biomass with sorbent enabled CO2 capture

    Directory of Open Access Journals (Sweden)

    S. Rupesh

    2016-06-01

    Full Text Available The work deals with the modelling and simulation of carbon dioxide capture in air–steam gasification of saw dust using ASPEN Plus process simulator. The proposed quasi-steady state model incorporates pyrolysis, tar cracking and char conversion using existing experimental data. Prediction accuracy of the developed model is validated by comparing with available experimental results. Effects of CaO addition in air–steam gasification are analysed through key operating parameters such as gasification temperature, equivalence ratio, steam to biomass ratio and gasification efficiency. Maximum H2 mole fraction of 31.17% is obtained at a temperature of 900 K, equivalence ratio of 0.25, and steam to biomass ratio and sorbent to biomass ratio of unity. The H2 and CO2 mole fractions are found to be increased and decreased by 28.10% and 42.6%, respectively, when compared with the corresponding non- sorbent case.

  16. Simulation and validation of chemical-looping combustion using ASPEN plus

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ling [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States); Zhang, Zheming; Agarwal, Ramesh K. [Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States)

    2013-07-01

    Laboratory-scale experimental studies have demonstrated that Chemical-Looping Combustion (CLC) is an advanced technology which holds great potential for high-efficiency low-cost carbon capture. The generated syngas in CLC is subsequently oxidized to CO2 and H2O by reaction with an oxygen carrier. In this paper, process-level models of CLC are established in ASPEN Plus code for detailed simulations. The entire CLC process, from the beginning of coal gasification to reduction and oxidation of the oxygen carrier is modeled. The heat content of each major component such as fuel and air reactors and air/flue gas heat exchangers is carefully examined. Large amount of energy is produced in the fuel reactor, but energy needs to be supplied to the air reactor. The overall performance and efficiency of the modeled CLC systems are also evaluated.

  17. Genome-wide association implicates numerous genes and pleiotropy underlying ecological trait variation in natural populations of Populus trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    McKown, Athena [University of British Columbia, Vancouver; Klapste, Jaroslav [University of British Columbia, Vancouver; Guy, Robert [University of British Columbia, Vancouver; Geraldes, Armando [University of British Columbia, Vancouver; Porth, Ilga [University of British Columbia, Vancouver; Hannemann, Jan [University of Victoria, Canada; Friedmann, Michael [University of British Columbia, Vancouver; Muchero, Wellington [ORNL; Tuskan, Gerald A [ORNL; Ehlting, Juergen [University of Victoria, Canada; Cronk, Quentin [University of British Columbia, Vancouver; El-Kassaby, Yousry [University of British Columbia, Vancouver; Mansfield, Shawn [University of British Columbia, Vancouver; Douglas, Carl [University of British Columbia, Vancouver

    2014-01-01

    To uncover the genetic basis of phenotypic trait variation, we used 448 unrelated wild accessions of black cottonwood (Populus trichocarpa Torr. & Gray) from natural populations throughout western North America. Extensive information from large-scale trait phenotyping (with spatial and temporal replications within a common garden) and genotyping (with a 34K Populus SNP array) of all accessions were used for gene discovery in a genome-wide association study (GWAS).

  18. Basal area growth for aspen suckers under simulated browsing on Cedar Mountain, southern Utah, western United States of America

    Science.gov (United States)

    K. Tshireletso; J. C. Malechek; D. L. Bartos

    2010-01-01

    The objective of the study was to determine the effects of season and intensity of clipping using simulated browsing on suckers' (Populus tremulaides Michx.) basal area growth on Cedar Mountain, Southern Utah, Western United States of America. Three randomly selected stands measuring 70 m x 70 m were clear-felled in mid-July, 2005, and fenced. Simulated browsing...

  19. Comprehensive Analysis of NAC Domain Transcription Factor Gene Family in Populus trichocarpa

    Science.gov (United States)

    2010-01-01

    Background NAC (NAM, ATAF1/2 and CUC2) domain proteins are plant-specific transcriptional factors known to play diverse roles in various plant developmental processes. NAC transcription factors comprise of a large gene family represented by more than 100 members in Arabidopsis, rice and soybean etc. Recently, a preliminary phylogenetic analysis was reported for NAC gene family from 11 plant species. However, no comprehensive study incorporating phylogeny, chromosomal location, gene structure, conserved motifs, and expression profiling analysis has been presented thus far for the model tree species Populus. Results In the present study, a comprehensive analysis of NAC gene family in Populus was performed. A total of 163 full-length NAC genes were identified in Populus, and they were phylogeneticly clustered into 18 distinct subfamilies. The gene structure and motif compositions were considerably conserved among the subfamilies. The distributions of 120 Populus NAC genes were non-random across the 19 linkage groups (LGs), and 87 genes (73%) were preferentially retained duplicates that located in both duplicated regions. The majority of NACs showed specific temporal and spatial expression patterns based on EST frequency and microarray data analyses. However, the expression patterns of a majority of duplicate genes were partially redundant, suggesting the occurrence of subfunctionalization during subsequent evolutionary process. Furthermore, quantitative real-time RT-PCR (RT-qPCR) was performed to confirm the tissue-specific expression patterns of 25 NAC genes. Conclusion Based on the genomic organizations, we can conclude that segmental duplications contribute significantly to the expansion of Populus NAC gene family. The comprehensive expression profiles analysis provides first insights into the functional divergence among members in NAC gene family. In addition, the high divergence rate of expression patterns after segmental duplications indicates that NAC genes in

  20. Genome resequencing in Populus: Revealing large-scale genome variation and implications on specialized-trait genomics

    Energy Technology Data Exchange (ETDEWEB)

    Muchero, Wellington [ORNL; Labbe, Jessy L [ORNL; Priya, Ranjan [University of Tennessee, Knoxville (UTK); DiFazio, Steven P [West Virginia University, Morgantown; Tuskan, Gerald A [ORNL

    2014-01-01

    To date, Populus ranks among a few plant species with a complete genome sequence and other highly developed genomic resources. With the first genome sequence among all tree species, Populus has been adopted as a suitable model organism for genomic studies in trees. However, far from being just a model species, Populus is a key renewable economic resource that plays a significant role in providing raw materials for the biofuel and pulp and paper industries. Therefore, aside from leading frontiers of basic tree molecular biology and ecological research, Populus leads frontiers in addressing global economic challenges related to fuel and fiber production. The latter fact suggests that research aimed at improving quality and quantity of Populus as a raw material will likely drive the pursuit of more targeted and deeper research in order to unlock the economic potential tied in molecular biology processes that drive this tree species. Advances in genome sequence-driven technologies, such as resequencing individual genotypes, which in turn facilitates large scale SNP discovery and identification of large scale polymorphisms are key determinants of future success in these initiatives. In this treatise we discuss implications of genome sequence-enable technologies on Populus genomic and genetic studies of complex and specialized-traits.

  1. Productivity, water-use efficiency and tolerance to moderate water deficit correlate in 33 poplar genotypes from a Populus deltoides x Populus trichocarpa F1 progeny.

    Science.gov (United States)

    Monclus, R; Villar, M; Barbaroux, C; Bastien, C; Fichot, R; Delmotte, F M; Delay, D; Petit, J-M; Bréchet, C; Dreyer, E; Brignolas, F

    2009-11-01

    Genotypic variability for productivity, water-use efficiency and leaf traits in 33 genotypes selected from an F1 progeny of Populus deltoides Bartr. ex Marsh x Populus trichocarpa L. was explored under optimal and moderate water-deficit conditions. Saplings of the 33 genotypes were grown in a two-plot open field at INRA Orléans (France) and coppiced every year. A moderate water deficit was induced during two successive years on one plot by withholding irrigation, while the second one remained irrigated (control). Stem biomass and leaf structure (e.g., specific leaf area and leaf area) were measured in 2004 and 2005 and functional leaf traits (e.g., carbon isotope discrimination, Delta) were measured only in 2004. Tolerance to water deficit was estimated at genotype level as the ability to limit losses in biomass production in water deficit versus control trees. Stem biomass, leaf structure and Delta displayed a significant genotypic variability whatever the irrigation regime. For all traits, genotype ranks remained stable across years for similar irrigation conditions. Carbon isotope discrimination scaled negatively with productivity and leaf nitrogen content in controls. The most productive genotypes were the least tolerant to moderate water deficit. No relationship was evidenced between Delta and the level of tolerance to water deficit. The relationships between traits evidenced in this collection of P. deltoides x P. trichocarpa F1 genotypes contrast with the ones that were previously detected in a collection of P. deltoides x Populus nigra L. cultivars tested in the same field trial.

  2. Transformation of poplar (Populus alba) plastids and expression of foreign proteins in tree chloroplasts.

    Science.gov (United States)

    Okumura, Satoru; Sawada, Machiko; Park, Yong Woo; Hayashi, Takahisa; Shimamura, Masaki; Takase, Hisabumi; Tomizawa, Ken-Ichi

    2006-10-01

    Plastid transformation offers several unique advantages compared with nuclear genome transformation, such as high level of transgene expression within plastids, expressing multiple transgenes as operons, lack of position effect due to site-specific transgene integration, and reducing risks of gene flow via pollen due to maternal inheritance of the plastid genome. Plastid transformation has been applied to several herbal species, but as yet there are no applications to tree species. We report here the first successful plastid transformation in a tree species, Populus alba. A vector for plastid transformation of poplar (Populus alba) was constructed, which carried the spectinomycin resistance gene and the green fluorescence protein gene as marker genes. In the regenerated shoots, the site-specific integration of foreign genes and the establishment of a high homoplastomic state were confirmed. Immunoblot analysis and histological observations corroborated the accumulation of green fluorescence protein in chloroplasts. The establishment of a plastid transformation system in poplar provides a novel tool for tree biotechnology.

  3. Cytogenetic Analysis of Populus trichocarpa - Ribosomal DNA, Telomere Repeat Sequence, and Marker-selected BACs

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Gunter, Lee E [ORNL; DiFazio, Stephen P [West Virginia University

    2009-01-01

    The 18S-28S rDNA and 5S rDNA loci in Populus trichocarpa were localized using fluorescent in situ hybridization (FISH). Two 18S-28S rDNA sites and one 5S rDNA site were identified and located at the ends of 3 different chromosomes. FISH signals from the Arabidopsis -type telomere repeat sequence were observed at the distal ends of each chromosome. Six BAC clones selected from 2 linkage groups based on genome sequence assembly (LG-I and LG-VI) were localized on 2 chromosomes, as expected. BACs from LG-I hybridized to the longest chromosome in the complement. All BAC positions were found to be concordant with sequence assembly positions. BAC-FISH will be useful for delineating each of the Populus trichocarpa chromosomes and improving the sequence assembly of this model angiosperm tree species.

  4. Biochemical basis of drought tolerance in hybrid Populus grown under field production conditions. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Tschaplinski, T.J.; Tuskan, G.A. [Oak Ridge National Lab., TN (United States); Wierman, C. [Boise Cascade Corp., Wallula, WA (United States)

    1997-04-01

    The purpose of this cooperative effort was to assess the use of osmotically active compounds as molecular selection criteria for drought tolerance in Populus in a large-scale field trial. It is known that some plant species, and individuals within a plant species, can tolerate increasing stress associated with reduced moisture availability by accumulating solutes. The biochemical matrix of such metabolites varies among species and among individuals. The ability of Populus clones to tolerate drought has equal value to other fiber producers, i.e., the wood products industry, where irrigation is used in combination with other cultural treatments to obtain high dry weight yields. The research initially involved an assessment of drought stress under field conditions and characterization of changes in osmotic constitution among the seven clones across the six moisture levels. The near-term goal was to provide a mechanistic basis for clonal differences in productivity under various irrigation treatments over time.

  5. Genome-wide identification, classification, and expression analysis of 14-3-3 gene family in Populus.

    Science.gov (United States)

    Tian, Fengxia; Wang, Tan; Xie, Yuli; Zhang, Jin; Hu, Jianjun

    2015-01-01

    In plants, 14-3-3 proteins are encoded by a large multigene family and are involved in signaling pathways to regulate plant development and protection from stress. Although twelve Populus 14-3-3s were identified based on the Populus trichocarpa genome V1.1 in a previous study, no systematic analysis including genome organization, gene structure, duplication relationship, evolutionary analysis and expression compendium has been conducted in Populus based on the latest P. trichocarpa genome V3.0. Here, a comprehensive analysis of Populus 14-3-3 family is presented. Two new 14-3-3 genes were identified based on the latest P. trichocarpa genome. In P. trichocarpa, fourteen 14-3-3 genes were grouped into ε and non-ε group. Exon-intron organizations of Populus 14-3-3s are highly conserved within the same group. Genomic organization analysis indicated that purifying selection plays a pivotal role in the retention and maintenance of Populus 14-3-3 family. Protein conformational analysis indicated that Populus 14-3-3 consists of a bundle of nine α-helices (α1-α9); the first four are essential for formation of the dimer, while α3, α5, α7, and α9 form a conserved peptide-binding groove. In addition, α1, α3, α5, α7, and α9 were evolving at a lower rate, while α2, α4, and α6 were evolving at a relatively faster rate. Microarray analyses showed that most Populus 14-3-3s are differentially expressed across tissues and upon exposure to various stresses. The gene structures and their coding protein structures of Populus 14-3-3s are highly conserved among group members, suggesting that members of the same group might also have conserved functions. Microarray and qRT-PCR analyses showed that most Populus 14-3-3s were differentially expressed in various tissues and were induced by various stresses. Our investigation provided a better understanding of the complexity of the 14-3-3 gene family in poplars.

  6. Effects of elevated CO2 leaf diets on gypsy moth (Lepidoptera: Lymantriidae) respiration rates.

    Science.gov (United States)

    Foss, Anita R; Mattson, William J; Trier, Terry M

    2013-06-01

    Elevated levels of CO2 affect plant growth and leaf chemistry, which in turn can alter host plant suitability for insect herbivores. We examined the suitability of foliage from trees grown from seedlings since 1997 at Aspen FACE as diet for the gypsy moth (Lymantria dispar L.) Lepidoptera: Lymantriidae: paper birch (Betula papyrifera Marshall) in 2004-2005, and trembling aspen (Populus tremuloides Michaux) in 2006-2007, and measured consequent effects on larval respiration. Leaves were collected for diet and leaf chemistry (nutritional and secondary compound proxies) from trees grown under ambient (average 380 ppm) and elevated CO2 (average 560 ppm) conditions. Elevated CO2 did not significantly alter birch or aspen leaf chemistry compared with ambient levels with the exception that birch percent carbon in 2004 and aspen moisture content in 2006 were significantly lowered. Respiration rates were significantly higher (15-59%) for larvae reared on birch grown under elevated CO2 compared with ambient conditions, but were not different on two aspen clones, until larvae reached the fifth instar, when those consuming elevated CO2 leaves on clone 271 had lower (26%) respiration rates, and those consuming elevated CO2 leaves on clone 216 had higher (36%) respiration rates. However, elevated CO2 had no apparent effect on the respiration rates of pupae derived from larvae fed either birch or aspen leaves. Higher respiration rates for larvae fed diets grown under ambient or elevated CO2 demonstrates their lower efficiency of converting chemical energy of digested food stuffs extracted from such leaves into their biosynthetic processes.

  7. Monitoring ethylene and oxygen emission during water stress of Populus alba leaves

    Science.gov (United States)

    Acosta-Avalos, D.; Alvarado-Gil, J. J.; Vargas, H.

    2005-06-01

    Photoacoustic techniques were used to analyze the emission of ethylene and photosynthetic oxygen, as function of time, in water stressed leaves of poplar (Populus alba). Oxygen evolution was measured using the OPC technique, with an electret microphone as the photoacoustic cell. Ethylene emission was measured using an intracavity photoacoustic cell inside a CO2 laser. The results obtained could be used in studies of stomatal closure dynamics or photosynthetic activity.

  8. Identification and Biochemical Characterization of Four Wood-Associated Glucuronoxylan Methyltransferases in Populus

    Science.gov (United States)

    Yuan, Youxi; Teng, Quincy; Zhong, Ruiqin; Ye, Zheng-Hua

    2014-01-01

    Wood is one of the promising bioenergy feedstocks for lignocellulosic biofuel production. Understanding how wood components are synthesized will help us design strategies for better utilization of wood for biofuel production. One of the major wood components is xylan, in which about 10% of xylosyl residues are substituted with glucuronic acid (GlcA) side chains. All the GlcA side chains of xylan in wood of Populus trichocarpa are methylated, which is different from Arabidopsis xylan in which about 60% of GlcA side chains are methylated. Genes responsible for methylation of GlcA side chains in Populus xylan have not been identified. Here, we report genetic and biochemical analyses of four DUF579 domain-containing proteins, PtrGXM1, PtrGXM2, PtrGXM3 and PtrGXM4, from Populus trichocarpa and their roles in GlcA methylation in xylan. The PtrGXM genes were found to be highly expressed in wood-forming cells and their encoded proteins were shown to be localized in the Golgi. When overexpressed in the Arabidopsis gxm1/2/3 triple mutant, PtrGXMs were able to partially complement the mutant phenotypes including defects in glucuronoxylan methyltransferase activity and GlcA methylation in xylan, indicating that PtrGXMs most likely function as glucuronoxylan methyltransferases. Direct evidence was provided by enzymatic analysis of recombinant PtrGXM proteins showing that they possessed a methyltransferase activity capable of transferring the methyl group onto GlcA-substituted xylooligomers. Kinetic analysis showed that PtrGXMs exhibited differential affinities toward the GlcA-substituted xylooligomer acceptor with PtrGXM3 and PtrGXM4 having 10 times higher Km values than PtrGXM1 and PtrGXM2. Together, these findings indicate that PtrGXMs are methyltransferases mediating GlcA methylation in Populus xylan during wood formation. PMID:24523868

  9. Molecular Evolution of Trehalose-6-Phosphate Synthase (TPS) Gene Family in Populus, Arabidopsis and Rice

    Science.gov (United States)

    Yang, Hai-Ling; Liu, Yan-Jing; Wang, Cai-Ling; Zeng, Qing-Yin

    2012-01-01

    Trehalose-6-phosphate synthase (TPS) plays important roles in trehalose metabolism and signaling. Plant TPS proteins contain both a TPS and a trehalose-6-phosphate phosphatase (TPP) domain, which are coded by a multi-gene family. The plant TPS gene family has been divided into class I and class II. A previous study showed that the Populus, Arabidopsis, and rice genomes have seven class I and 27 class II TPS genes. In this study, we found that all class I TPS genes had 16 introns within the protein-coding region, whereas class II TPS genes had two introns. A significant sequence difference between the two classes of TPS proteins was observed by pairwise sequence comparisons of the 34 TPS proteins. A phylogenetic analysis revealed that at least seven TPS genes were present in the monocot–dicot common ancestor. Segmental duplications contributed significantly to the expansion of this gene family. At least five and three TPS genes were created by segmental duplication events in the Populus and rice genomes, respectively. Both the TPS and TPP domains of 34 TPS genes have evolved under purifying selection, but the selective constraint on the TPP domain was more relaxed than that on the TPS domain. Among 34 TPS genes from Populus, Arabidopsis, and rice, four class I TPS genes (AtTPS1, OsTPS1, PtTPS1, and PtTPS2) were under stronger purifying selection, whereas three Arabidopsis class I TPS genes (AtTPS2, 3, and 4) apparently evolved under relaxed selective constraint. Additionally, a reverse transcription polymerase chain reaction analysis showed the expression divergence of the TPS gene family in Populus, Arabidopsis, and rice under normal growth conditions and in response to stressors. Our findings provide new insights into the mechanisms of gene family expansion and functional evolution. PMID:22905132

  10. Morphological study of the leaves of two European black poplar (Populus nigra L.) populations in Slovenia

    OpenAIRE

    Jarni, Kristjan; Vaupotič, Urška; Božič, Gregor; Brus, Robert

    2010-01-01

    Background and Purpose: Conservation efforts across Europe and a substantial lack of information regarding the present status of black poplar (Populus nigra L.) in Slovenia led us to conduct this research. The objectives were to determine the presence of preserved native black poplar in Slovenia, to evaluate the variation within and between two selected populations, and to evaluate the condition of these populations, which is important for enabling their long-term gene pool conservation. ...

  11. A role for stomata in regulating water use efficiency in Populus ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... The. cDNA of Populus×euramericana clones, PdERECTA, was cloned using a systematic reverse transcriptase (RT)-PCR-based strategy. cDNA syntheses were performed using the mRNA selective PCR. Ver.1.1 kit (TaKaRa). The cDNA was amplified using the TaKaRa Ex. Taq kit in a 50 µl volume, with 35 ...

  12. Inducing triploids and tetraploids with high temperatures in Populus sect. Tacamahaca.

    Science.gov (United States)

    Guo, Liqin; Xu, Wenting; Zhang, Yan; Zhang, Jinfeng; Wei, Zunzheng

    2017-02-01

    This study is the first to report that triploids and tetraploids have been successfully produced through embryo sac and zygotic embryo chromosome doubling with high temperatures in P. simonii Carr. and its hybrid. A new synthetic polyploid induced by hybridization with unreduced gametes and heterozygotic embryo chromosome doubling can effectively combine polyploidy and heterosis, which can provide two major breeding advantages. In Populus, successfully creating and cultivating new polyploid varieties have economic and ecological production value. This was the first successful study in which embryo sac and zygotic embryo chromosome doubling was induced using high temperatures to produce triploids and tetraploids in Populus simonii Carr. and its hybrid, P. simonii × P. nigra var. Italica, of Populus sect. Tacamahaca. The relationship between flower bud morphological characteristics (time after pollination) and female meiotic stage (embryo sac and zygotic embryo development) was established to guide the induction treatment period. In the resulting progeny, 37 triploids and 12 tetraploids were obtained and identified using flow cytometry. The optimal temperatures for embryo sac and zygotic embryo chromosome doubling were 38 and 41 °C, respectively. Cytogenetic analysis revealed that 66-72 h after pollination (HAP), a period characterized by a high proportion of one-nucleate and two-nucleate embryo sacs, was the optimal period for embryo sac chromosome doubling. For zygotic embryo chromosome doubling, 168 HAP was the optimal induction period, as there was a high proportion of two-cell and four-cell proembryos. The results indicate that inducing embryo sac and zygotic embryo chromosome doubling is an ideal method for producing polyploids. The methods for inducing polyploids and for evaluating ploidy and offspring with different ploidies and heterozygosity in this study will be useful for genetic research and Populus breeding programmes.

  13. Cytogenetic Analysis of Populus trichocarpa - Ribosomal DNA, Telomere Repeat Sequence, and Marker-selected BACs

    Science.gov (United States)

    M.N. lslam-Faridi; C.D. Nelson; S.P. DiFazio; L.E. Gunter; G.A. Tuskan

    2009-01-01

    The 185-285 rDNA and 55 rDNA loci in Populus trichocarpa were localized using fluorescent in situ hybridization (FISH). Two 185-285 rDNA sites and one 55 rDNA site were identified and located at the ends of 3 different chromosomes. FISH signals from the Arabidopsis-type telomere repeat sequence were observed at the distal ends of each chromosome. Six BAC clones...

  14. PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

    OpenAIRE

    Qiang Zhao; Junwen Pu; Shulei Mao; Guibo Qi

    2010-01-01

    To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED) was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp con...

  15. Intra-annual growth and mortality of four Populus clones in pure and mixed plantings

    Science.gov (United States)

    Warren D. Devine; Constance A. Harrington; Dean S. DeBell

    2010-01-01

    Intra-annual growth rates were assessed during 3 years for four Populus clones grown in pure and mixed clonal stands at square spacings of 0.5, 1.0, and 1.5 m in western Washington, USA. Height growth rate peaked in August, except at the 0.5-m spacing where it peaked in July and June in years 2 and 3, respectively. Diameter growth rate generally...

  16. Admixture mapping of quantitative traits in Populus hybrid zones: power and limitations

    Science.gov (United States)

    Lindtke, D; González-Martínez, S C; Macaya-Sanz, D; Lexer, C

    2013-01-01

    Uncovering the genetic architecture of species differences is of central importance for understanding the origin and maintenance of biological diversity. Admixture mapping can be used to identify the number and effect sizes of genes that contribute to the divergence of ecologically important traits, even in taxa that are not amenable to laboratory crosses because of their long generation time or other limitations. Here, we apply admixture mapping to naturally occurring hybrids between two ecologically divergent Populus species. We map quantitative trait loci for eight leaf morphological traits using 77 mapped microsatellite markers from all 19 chromosomes of Populus. We apply multivariate linear regression analysis allowing the modeling of additive and non-additive gene action and identify several candidate genomic regions associated with leaf morphology using an information-theoretic approach. We perform simulation studies to assess the power and limitations of admixture mapping of quantitative traits in natural hybrid populations for a variety of genetic architectures and modes of gene action. Our results indicate that (1) admixture mapping has considerable power to identify the genetic architecture of species differences if sample sizes and marker densities are sufficiently high, (2) modeling of non-additive gene action can help to elucidate the discrepancy between genotype and phenotype sometimes seen in interspecific hybrids, and (3) the genetic architecture of leaf morphological traits in the studied Populus species involves complementary and overdominant gene action, providing the basis for rapid adaptation of these ecologically important forest trees. PMID:23860234

  17. Isolation and characterization of cDNAs encoding leucoanthocyanidin reductase and anthocyanidin reductase from Populus trichocarpa.

    Directory of Open Access Journals (Sweden)

    Lijun Wang

    Full Text Available Proanthocyanidins (PAs contribute to poplar defense mechanisms against biotic and abiotic stresses. Transcripts of PA biosynthetic genes accumulated rapidly in response to infection by the fungus Marssonina brunnea f.sp. multigermtubi, treatments of salicylic acid (SA and wounding, resulting in PA accumulation in poplar leaves. Anthocyanidin reductase (ANR and leucoanthocyanidin reductase (LAR are two key enzymes of the PA biosynthesis that produce the main subunits: (+-catechin and (--epicatechin required for formation of PA polymers. In Populus, ANR and LAR are encoded by at least two and three highly related genes, respectively. In this study, we isolated and functionally characterized genes PtrANR1 and PtrLAR1 from P. trichocarpa. Phylogenetic analysis shows that Populus ANR1 and LAR1 occurr in two distinct phylogenetic lineages, but both genes have little difference in their tissue distribution, preferentially expressed in roots. Overexpression of PtrANR1 in poplar resulted in a significant increase in PA levels but no impact on catechin levels. Antisense down-regulation of PtrANR1 showed reduced PA accumulation in transgenic lines, but increased levels of anthocyanin content. Ectopic expression of PtrLAR1 in poplar positively regulated the biosynthesis of PAs, whereas the accumulation of anthocyanin and flavonol was significantly reduced (P<0.05 in all transgenic plants compared to the control plants. These results suggest that both PtrANR1 and PtrLAR1 contribute to PA biosynthesis in Populus.

  18. Soil nitrogen limitation does not impact nighttime water loss in Populus.

    Science.gov (United States)

    Howard, Ava R; Donovan, Lisa A

    2010-01-01

    Nighttime transpirational water loss from C(3) trees occurs without carbon gain and is both common and substantial. However, the magnitude of this water loss varies and a better understanding of the environmental factors driving this variation is needed. We investigated the response of nighttime conductance (g(night)) and transpiration (E(night)) to soil nitrogen limitation. We used instantaneous gas exchange measurements in greenhouse studies of Populus angustifolia James (narrowleaf cottonwood) and Populus balsamifera L. spp. trichocarpa (Torr. & A. Gray ex Hook.) Brayshaw (black cottonwood). g(night) for sufficiently watered plants ranged from 0.045 to 0.308 mol m(-2) s(-1) for P. balsamifera and 0.037 to 0.188 mol m(-2) s(-1) for P. angustifolia, which was much larger than minimum leaf conductance (g(min); up to 0.005 mol m(-2) s(-1) in the dark). Long-term nitrogen limitation sufficient to substantially reduce biomass did not affect g(night) or E(night) when potentially confounding water stress effects were eliminated. We conclude that nighttime water loss from two Populus species is large and although it is under stomatal control is not regulated at night in response to soil nitrogen availability.

  19. Genome-Wide Identification of the Invertase Gene Family in Populus.

    Science.gov (United States)

    Chen, Zhong; Gao, Kai; Su, Xiaoxing; Rao, Pian; An, Xinmin

    2015-01-01

    Invertase plays a crucial role in carbohydrate partitioning and plant development as it catalyses the irreversible hydrolysis of sucrose into glucose and fructose. The invertase family in plants is composed of two sub-families: acid invertases, which are targeted to the cell wall and vacuole; and neutral/alkaline invertases, which function in the cytosol. In this study, 5 cell wall invertase genes (PtCWINV1-5), 3 vacuolar invertase genes (PtVINV1-3) and 16 neutral/alkaline invertase genes (PtNINV1-16) were identified in the Populus genome and found to be distributed on 14 chromosomes. A comprehensive analysis of poplar invertase genes was performed, including structures, chromosome location, phylogeny, evolutionary pattern and expression profiles. Phylogenetic analysis indicated that the two sub-families were both divided into two clades. Segmental duplication is contributed to neutral/alkaline sub-family expansion. Furthermore, the Populus invertase genes displayed differential expression in roots, stems, leaves, leaf buds and in response to salt/cold stress and pathogen infection. In addition, the analysis of enzyme activity and sugar content revealed that invertase genes play key roles in the sucrose metabolism of various tissues and organs in poplar. This work lays the foundation for future functional analysis of the invertase genes in Populus and other woody perennials.

  20. Gene Structures, Classification, and Expression Models of the DREB Transcription Factor Subfamily in Populus trichocarpa

    Science.gov (United States)

    Chen, Yunlin; Zhang, Haizhen; Mao, Xuliang; Li, Chenghao

    2013-01-01

    We identified 75 dehydration-responsive element-binding (DREB) protein genes in Populus trichocarpa. We analyzed gene structures, phylogenies, domain duplications, genome localizations, and expression profiles. The phylogenic construction suggests that the PtrDREB gene subfamily can be classified broadly into six subtypes (DREB A-1 to A-6) in Populus. The chromosomal localizations of the PtrDREB genes indicated 18 segmental duplication events involving 36 genes and six redundant PtrDREB genes were involved in tandem duplication events. There were fewer introns in the PtrDREB subfamily. The motif composition of PtrDREB was highly conserved in the same subtype. We investigated expression profiles of this gene subfamily from different tissues and/or developmental stages. Sixteen genes present in the digital expression analysis had high levels of transcript accumulation. The microarray results suggest that 18 genes were upregulated. We further examined the stress responsiveness of 15 genes by qRT-PCR. A digital northern analysis showed that the PtrDREB17, 18, and 32 genes were highly induced in leaves under cold stress, and the same expression trends were shown by qRT-PCR. Taken together, these observations may lay the foundation for future functional analyses to unravel the biological roles of Populus' DREB genes. PMID:24324388