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Sample records for leaf trait spectrum

  1. Testing models for the leaf economics spectrum with leaf and whole-plant traits in Arabidopsis thaliana.

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    Blonder, Benjamin; Vasseur, François; Violle, Cyrille; Shipley, Bill; Enquist, Brian J; Vile, Denis

    2015-05-08

    The leaf economics spectrum (LES) describes strong relationships between multiple functional leaf traits that determine resource fluxes in vascular plants. Five models have been proposed to explain these patterns: two based on patterns of structural allocation, two on venation networks and one on resource allocation to cell walls and cell contents. Here we test these models using data for leaf and whole-plant functional traits. We use structural equation modelling applied to multiple ecotypes, recombinant inbred lines, near isogenic lines and vascular patterning mutants of Arabidopsis thaliana that express LES trait variation. We show that a wide variation in multiple functional traits recapitulates the LES at the whole-plant scale. The Wright et al. (2004) model and the Blonder et al. (2013) venation network model cannot be rejected by data, while two simple models and the Shipley et al. (2006) allocation model are rejected. Venation networks remain a key hypothesis for the origin of the LES, but simpler explanations also cannot be ruled out.

  2. A plant economics spectrum in Mediterranean forests along environmental gradients: is there coordination among leaf, stem and root traits?

    NARCIS (Netherlands)

    Riva, de la E.G.; Tosto, A.; Perez-Ramos, I.M.; Navarro-Fernandez, C.M.; Olmos, M.; Anten, N.P.R.; Maranon, T.; Villar, R.

    2016-01-01

    Questions: Is there any evidence of coordination among leaf, stem and root traits, and thereby of the existence of a plant economics spectrum at the species and community level in Mediterranean forests? Are these traits related to plant size and seedmass? Location: Mediterranean forests and shrublan

  3. A plant economics spectrum in Mediterranean forests along environmental gradients: is there coordination among leaf, stem and root traits?

    NARCIS (Netherlands)

    Riva, de la E.G.; Tosto, A.; Perez-Ramos, I.M.; Navarro-Fernandez, C.M.; Olmos, M.; Anten, N.P.R.; Maranon, T.; Villar, R.

    2016-01-01

    Questions: Is there any evidence of coordination among leaf, stem and root traits, and thereby of the existence of a plant economics spectrum at the species and community level in Mediterranean forests? Are these traits related to plant size and seedmass? Location: Mediterranean forests and

  4. The worldwide leaf economics spectrum

    NARCIS (Netherlands)

    Wright, I.J.; Reich, P.B.; Westoby, M.; Ackerly, D.D.; Baruch, Z.; Bongers, F.J.J.M.; Cavender-Bares, J.; Chapin, T.; Cornelissen, J.H.C.; Diemer, M.; Flexas, J.; Garnier, E.; Groom, P.K.; Gulias, J.; Hikosaka, K.; Lamont, B.B.; Lee, T.; Lee, W.; Lusk, C.; Midgley, J.J.; Navas, M.L.; Niinements, Ü.; Oleksyn, J.; Osada, N.; Poorter, H.; Poot, P.; Prior, L.; Pyankov, V.I.; Roumet, C.; Thomas, S.C.; Tjoelker, M.G.; Veneklaas, E.J.; Villar, R.

    2004-01-01

    Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients

  5. Novel evidence for within-species leaf economics spectrum at multiple spatial scales

    Directory of Open Access Journals (Sweden)

    Yu-Kun eHu

    2015-10-01

    Full Text Available Leaf economics spectrum (LES, characterizing covariation among a suite of leaf traits relevant to carbon and nutrient economics, has been examined largely among species but hardly within species. In addition, very little attempt has been made to examine whether the existence of LES depends on spatial scales. To address these questions, we quantified the variation and covariation of four leaf economic traits (specific leaf area, leaf dry matter content, leaf nitrogen and phosphorus contents in a cosmopolitan wetland species (Phragmites australis at three spatial (inter-regional, regional and site scales across most of the species range in China. The species expressed large intraspecific variation in the leaf economic traits at all of the three spatial scales. It also showed strong covariation among the four leaf economic traits across the species range. The coordination among leaf economic traits resulted in LES at all three scales and the environmental variables determining variation in leaf economic traits were different among the spatial scales. Our results provide novel evidence for within-species LES at multiple spatial scales, indicating that resource trade-off could also constrain intraspecific trait variation mainly driven by climatic and/or edaphic differences.

  6. Maize YABBY genes drooping leaf1 and drooping leaf2 affect agronomic traits by regulating leaf architecture

    Science.gov (United States)

    Leaf architectural traits, such as length, width and angle, directly influence canopy structure and light penetration, photosynthate production and overall yield. We discovered and characterized a maize (Zea mays) mutant with aberrant leaf architecture we named drooping leaf1 (drl1), as leaf blades ...

  7. Leaf optical properties shed light on foliar trait variability at individual to global scales

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    Shiklomanov, A. N.; Serbin, S.; Dietze, M.

    2016-12-01

    Recent syntheses of large trait databases have contributed immensely to our understanding of drivers of plant function at the global scale. However, the global trade-offs revealed by such syntheses, such as the trade-off between leaf productivity and resilience (i.e. "leaf economics spectrum"), are often absent at smaller scales and fail to correlate with actual functional limitations. An improved understanding of how traits vary within communities, species, and individuals is critical to accurate representations of vegetation ecophysiology and ecological dynamics in ecosystem models. Spectral data from both field observations and remote sensing platforms present a potentially rich and widely available source of information on plant traits. In particular, the inversion of physically-based radiative transfer models (RTMs) is an effective and general method for estimating plant traits from spectral measurements. Here, we apply Bayesian inversion of the PROSPECT leaf RTM to a large database of field spectra and plant traits spanning tropical, temperate, and boreal forests, agricultural plots, arid shrublands, and tundra to identify dominant sources of variability and characterize trade-offs in plant functional traits. By leveraging such a large and diverse dataset, we re-calibrate the empirical absorption coefficients underlying the PROSPECT model and expand its scope to include additional leaf biochemical components, namely leaf nitrogen content. Our work provides a key methodological contribution as a physically-based retrieval of leaf nitrogen from remote sensing observations, and provides substantial insights about trait trade-offs related to plant acclimation, adaptation, and community assembly.

  8. Generality of leaf trait relationships: A test across six biomes

    Energy Technology Data Exchange (ETDEWEB)

    Reich, P.B. [Univ. of Minnesota, Saint Paul, MN (United States). Dept. of Forest Resources; Ellsworth, D.S. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science; Walters, M.B. [Michigan State Univ., East Lansing, MI (United States). Dept. of Forestry; Vose, J.M. [Forest Service, Otto, NC (United States). Coweeta Hydrological Lab.; Gresham, C. [Clemson Univ., Georgetown, SC (United States). Baruch Forest Inst.; Volin, J.C. [Florida Atlantic Univ., Davie, FL (United States). Div. of Science; Bowman, W.D. [Inst. of Arctic and Alpine Research, Boulder, CO (United States). Mountain Research Station]|[Univ. of Colorado, Boulder, CO (United States). Dept. of Evolutionary, Population, and Organismic Biology

    1999-09-01

    Convergence in interspecific leaf trait relationships across diverse taxonomic groups and biomes would have important evolutionary and ecological implications. Such convergence has been hypothesized to result from trade-offs that limit the combination of plant traits for any species. Here the authors address this issue by testing for biome differences in the slope and intercept of interspecific relationships among leaf traits: longevity, net photosynthetic capacity (A{sub max}), leaf diffusive conductance (G{sub S}), specific leaf area (SLA), and nitrogen (N) status, for more than 100 species in six distinct biomes of the Americas. The six biomes were: alpine tundra-subalpine forest ecotone, cold temperate forest-prairie ecotone, montane cool temperate forest, desert shrubland, subtropical forest, and tropical rain forest. Despite large differences in climate and evolutionary history, in all biomes mass-based leaf N (N{sub mass}), SLA, G{sub S}, and A{sub max} were positively related to one another and decreased with increasing leaf life span. The relationships between pairs of leaf traits exhibited similar slopes among biomes, suggesting a predictable set of scaling relationships among key leaf morphological, chemical, and metabolic traits that are replicated globally among terrestrial ecosystems regardless of biome or vegetation type. However, the intercept (i.e., the overall elevation of regression lines) of relationships between pairs of leaf traits usually differed among biomes. With increasing aridity across sites, species had greater A{sub max} for a given level of G{sub S} and lower SLA for any given leaf life span. Using principal components analysis, most variation among species was explained by an axis related to mass-based leaf traits (A{sub max}, N, and SLA) while a second axis reflected climate, G{sub S}, and other area-based leaf traits.

  9. The role of habitat filtering in the leaf economics spectrum and plant susceptibility to pathogen infection

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    Welsh, Miranda E; Cronin, James P.; Mitchell, Charles E.

    2016-01-01

    1.The Leaf Economics Spectrum (LES) describes global covariation in the traits of plant leaves. The LES is thought to arise from biophysical constraints and habitat filtering (ecological selection against unfit trait combinations along environmental gradients). However, the role of habitat filtering in generating the LES has not been tested experimentally.

  10. Evolution of the leaf economics spectrum in herbs: Evidence from environmental divergences in leaf physiology across Helianthus (Asteraceae).

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    Mason, Chase M; Donovan, Lisa A

    2015-10-01

    The leaf economics spectrum (LES) describes a major axis of plant functional trait variation worldwide, defining suites of leaf traits aligned with resource-acquisitive to resource-conservative ecological strategies. The LES has been interpreted to arise from leaf-level trade-offs among ecophysiological traits common to all plants. However, it has been suggested that the defining leaf-level trade-offs of the LES may not hold within specific functional groups (e.g., herbs) nor within many groups of closely related species, which challenges the usefulness of the LES paradigm across evolutionary scales. Here, we examine the evolution of the LES across 28 species of the diverse herbaceous genus Helianthus (the sunflowers), which occupies a wide range of habitats and climate variation across North America. Using a phylogenetic comparative approach, we find repeated evolution of more resource-acquisitive LES strategies in cooler, drier, and more fertile environments. We also find macroevolutionary correlations among LES traits that recapitulate aspects of the global LES, but with one major difference: leaf mass per area is uncorrelated with leaf lifespan. This indicates that whole-plant processes likely drive variation in leaf lifespan across Helianthus, rather than leaf-level trade-offs. These results suggest that LES patterns do not reflect universal physiological trade-offs at small evolutionary scales. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  11. Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

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    Roa-Fuentes, Lilia L; Templer, Pamela H; Campo, Julio

    2015-10-01

    Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

  12. Leafing patterns and leaf traits of four evergreen shrubs in the Patagonian Monte, Argentina

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    Campanella, María Victoria; Bertiller, Mónica B.

    2009-11-01

    We assessed leafing patterns (rate, timing, and duration of leafing) and leaf traits (leaf longevity, leaf mass per area and leaf-chemistry) in four co-occurring evergreen shrubs of the genus Larrea and Chuquiraga (each having two species) in the arid Patagonian Monte of Argentina. We asked whether species with leaves well-defended against water shortage (high LMA, leaf longevity, and lignin concentration, and low N concentration) have lower leaf production, duration of the leafing period, and inter-annual variation of leafing than species with the opposite traits. We observed two distinctive leafing patterns each related to one genus. Chuquiraga species produced new leaves concentrated in a massive short leafing event (5-48 days) while new leaves of Larrea species emerged gradually (128-258 days). Observed leafing patterns were consistent with simultaneous and successive leafing types previously described for woody plants. The peak of leaf production occurred earlier in Chuquiraga species (mid September) than in Larrea species (mid October-late November). Moreover, Chuquiraga species displayed leaves with the longest leaf lifespan, while leaves of Larrea species had the lowest LMA and the highest N and soluble phenolics concentrations. We also observed that only the leaf production of Larrea species increased in humid years. We concluded that co-occurring evergreen species in the Patagonian Monte displayed different leafing patterns, which were associated with some relevant leaf traits acting as plant defenses against water stress and herbivores. Differences in leafing patterns could provide evidence of ecological differentiation among coexisting species of the same life form.

  13. Leaf economics and hydraulic traits are decoupled in five species-rich tropical-subtropical forests.

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    Li, Le; McCormack, M Luke; Ma, Chengen; Kong, Deliang; Zhang, Qian; Chen, Xiaoyong; Zeng, Hui; Niinemets, Ülo; Guo, Dali

    2015-09-01

    Leaf economics and hydraulic traits are critical to leaf photosynthesis, yet it is debated whether these two sets of traits vary in a fully coordinated manner or there is room for independent variation. Here, we tested the relationship between leaf economics traits, including leaf nitrogen concentration and leaf dry mass per area, and leaf hydraulic traits including stomatal density and vein density in five tropical-subtropical forests. Surprisingly, these two suites of traits were statistically decoupled. This decoupling suggests that independent trait dimensions exist within a leaf, with leaf economics dimension corresponding to light capture and tissue longevity, and the hydraulic dimension to water-use and leaf temperature maintenance. Clearly, leaf economics and hydraulic traits can vary independently, thus allowing for more possible plant trait combinations. Compared with a single trait dimension, multiple trait dimensions may better enable species adaptations to multifarious niche dimensions, promote diverse plant strategies and facilitate species coexistence.

  14. Phenotypic selection on leaf ecophysiological traits in Helianthus

    NARCIS (Netherlands)

    Donovan, L.A.; Ludwig, F.; Rosenthal, D.R.; Rieseberg, L.H.; Dudley, S.A.

    2009-01-01

    Habitats that differ in soil resource availability are expected to differ for selection on resource-related plant traits. Here, we examined spatial and temporal variation in phenotypic selection on leaf ecophysiological traits for 10 Helianthus populations, including two species of hybrid origin, He

  15. Ontogeny strongly and differentially alters leaf economic and other key traits in three diverse Helianthus species.

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    Mason, Chase M; McGaughey, Sarah E; Donovan, Lisa A

    2013-10-01

    The leaf economics spectrum (LES) describes large cross-species variation in suites of leaf functional traits ranging from resource-acquisitive to resource-conservative strategies. Such strategies have been integral in explaining plant adaptation to diverse environments, and have been linked to numerous ecosystem processes. The LES has previously been found to be significantly modulated by climate, soil fertility, biogeography, growth form, and life history. One largely unexplored aspect of LES variation, whole-plant ontogeny, is investigated here using multiple populations of three very different species of sunflower: Helianthus annuus, Helianthus mollis, and Helianthus radula. Plants were grown under environmentally controlled conditions and assessed for LES and related traits at four key developmental stages, using recently matured leaves to standardize for leaf age. Nearly every trait exhibited a significant ontogenetic shift in one or more species, with trait patterns differing among populations and species. Photosynthetic rate, leaf nitrogen concentration, and leaf mass per area exhibited surprisingly large changes, spanning over two-thirds of the original cross-species LES variation and shifting from resource-acquisitive to resource-conservative strategies as the plants matured. Other traits being investigated in relation to the LES, such as leaf water content, pH, and vein density, also showed large changes. The finding that ontogenetic variation in LES strategy can be substantial leads to a recommendation of standardization by developmental stage when assessing 'species values' of labile traits for comparative approaches. Additionally, the substantial ontogenetic trait shifts seen within single individuals provide an opportunity to uncover the contribution of gene regulatory changes to variation in LES traits.

  16. Intraspecific Trait Variation and Coordination: Root and Leaf Economics Spectra in Coffee across Environmental Gradients.

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    Isaac, Marney E; Martin, Adam R; de Melo Virginio Filho, Elias; Rapidel, Bruno; Roupsard, Olivier; Van den Meersche, Karel

    2017-01-01

    Hypotheses on the existence of a universal "Root Economics Spectrum" (RES) have received arguably the least attention of all trait spectra, despite the key role root trait variation plays in resource acquisition potential. There is growing interest in quantifying intraspecific trait variation (ITV) in plants, but there are few studies evaluating (i) the existence of an intraspecific RES within a plant species, or (ii) how a RES may be coordinated with other trait spectra within species, such as a leaf economics spectrum (LES). Using Coffea arabica (Rubiaceae) as a model species, we measured seven morphological and chemical traits of intact lateral roots, which were paired with information on four key LES traits. Field collections were completed across four nested levels of biological organization. The intraspecific trait coefficient of variation (cv) ranged from 25 to 87% with root diameter and specific root tip density showing the lowest and highest cv, respectively. Between 27 and 68% of root ITV was explained by site identity alone for five of the seven traits measured. A single principal component explained 56.2% of root trait covariation, with plants falling along a RES from resource acquiring to conserving traits. Multiple factor analysis revealed significant orthogonal relationships between root and leaf spectra. RES traits were strongly orthogonal with respect to LES traits, suggesting these traits vary independently from one another in response to environmental cues. This study provides among the first evidence that plants from the same species differentiate from one another along an intraspecific RES. We find that in one of the world's most widely cultivated crops, an intraspecific RES is orthogonal to an intraspecific LES, indicating that above and belowground responses of plants to managed (or natural) environmental gradients are likely to occur independently from one another.

  17. Quantitative trait loci analysis of leaf morphology in rice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@The leaf morphology traits are important componem part of rice ideotype. The present study was conducted with a doubled haploid(DH) population of 117 lines derived from a cross between an indica variety, Zhaiyeqing 8(ZYQ 8) and a japonica variety, Jingxi 17(JX 17). The QTLs responsible for area, perimeter, length, width, and length/width of flag leaf, the second upside-down leaf, and the third upside-down leaf were surveyed and analyzed based on genetic linkage map of 243 molecular markers.

  18. Leaf habit and woodiness regulate different leaf economy traits at a given nutrient supply

    NARCIS (Netherlands)

    Ordonez, J.C.; Bodegom, van P.M.; Witte, J.P.M.; Bartholomeus, R.P.; Dobben, van H.F.; Aerts, R.

    2010-01-01

    The large variation in the relationships between environmental factors and plant traits observed in natural communities exemplifies the alternative solutions that plants have developed in response to the same environmental limitations. Qualitative attributes, such as growth form, woodiness, and leaf

  19. Global variability in leaf respiration in relation to climate, plant functional types and leaf traits

    NARCIS (Netherlands)

    Atkin, O.; Bloomfield, K.; Reich, P.B.; Tjoelker, M.G.; Asner, G.; Bonal, D.; Bönisch, G.; Poorter, L.

    2015-01-01

    Leaf dark respiration (R-dark) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of R-dark and associated leaf traits. Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwood

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

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

    2017-02-01

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

  1. Intraspecific relationships among wood density, leaf structural traits and environment in four co-occurring species of Nothofagus in New Zealand.

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    Sarah J Richardson

    Full Text Available Plant functional traits capture important variation in plant strategy and function. Recent literature has revealed that within-species variation in traits is greater than previously supposed. However, we still have a poor understanding of how intraspecific variation is coordinated among different traits, and how it is driven by environment. We quantified intraspecific variation in wood density and five leaf traits underpinning the leaf economics spectrum (leaf dry matter content, leaf mass per unit area, size, thickness and density within and among four widespread Nothofagus tree species in southern New Zealand. We tested whether intraspecific relationships between wood density and leaf traits followed widely reported interspecific relationships, and whether variation in these traits was coordinated through shared responses to environmental factors. Sample sites varied widely in environmental variables, including soil fertility (25-900 mg kg(-1 total P, precipitation (668-4875 mm yr(-1, temperature (5.2-12.4 °C mean annual temperature and latitude (41-46 °S. Leaf traits were strongly correlated with one another within species, but not with wood density. There was some evidence for a positive relationship between wood density and leaf tissue density and dry matter content, but no evidence that leaf mass or leaf size were correlated with wood density; this highlights that leaf mass per unit area cannot be used as a surrogate for component leaf traits such as tissue density. Trait variation was predicted by environmental factors, but not consistently among different traits; e.g., only leaf thickness and leaf density responded to the same environmental cues as wood density. We conclude that although intraspecific variation in wood density and leaf traits is strongly driven by environmental factors, these responses are not strongly coordinated among functional traits even across co-occurring, closely-related plant species.

  2. Identifying leaf traits that signal stress in TIR spectra

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    Buitrago Acevedo, Maria F.; Groen, Thomas A.; Hecker, Christoph A.; Skidmore, Andrew K.

    2017-03-01

    Plants under constant water and temperature stress experience a chain of reactions that in the long term alter their leaf traits (morphology, anatomy and chemistry). The use of these traits as proxies for assessing plant stress was so far mainly based on conventional laboratory methods, which are expensive and time-consuming. Remote sensing methods based on spectral changes can detect changes in pigments and productivity using the visible and near infrared. However, the use of infrared spectra, where changes in the spectra are associated with physical changes of the leaf, is still incipient. In this study plants of Rhododendron cf. catawbiense, were exposed to low temperatures and low soil water content during a six months experiment. The spectral response in the infrared region 1.4-16 μm, microstructural variables, leaf water content, leaf area and leaf molecules such as lignin and cellulose concentrations were measured in individual leaves after the period of stress. This study revealed that under cold conditions plants have most changes in leaf water content, lignin and cellulose concentrations and leaf area, while under drought conditions the most striking change is water loss. These leaf trait modifications are also correlated with changes in thermal infrared spectra, showing their potential as proxies for detecting plant stress in this species. A multinomial model allows the estimation of the stress treatments imposed on these plants from their infrared spectra. This model reveals a group of 15 bands in the SWIR and MWIR between 2.23 and 7.77 μm, which show relatively large changes, and had an overall accuracy of 87%. Finally, individual partial least squares regression models show that lignin, cellulose, leaf water content and leaf area are the leaf traits reacting significantly to long-term stress and that are also generating measurable changes in the infrared spectra. Although these models are based on laboratory data, the congruence of the identified

  3. Mechanisms behind the estimation of photosynthesis traits from leaf reflectance observations

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    Dechant, Benjamin; Cuntz, Matthias; Doktor, Daniel; Vohland, Michael

    2016-04-01

    Many studies have investigated the reflectance-based estimation of leaf chlorophyll, water and dry matter contents of plants. Only few studies focused on photosynthesis traits, however. The maximum potential uptake of carbon dioxide under given environmental conditions is determined mainly by RuBisCO activity, limiting carboxylation, or the speed of photosynthetic electron transport. These two main limitations are represented by the maximum carboxylation capacity, V cmax,25, and the maximum electron transport rate, Jmax,25. These traits were estimated from leaf reflectance before but the mechanisms underlying the estimation remain rather speculative. The aim of this study was therefore to reveal the mechanisms behind reflectance-based estimation of V cmax,25 and Jmax,25. Leaf reflectance, photosynthetic response curves as well as nitrogen content per area, Narea, and leaf mass per area, LMA, were measured on 37 deciduous tree species. V cmax,25 and Jmax,25 were determined from the response curves. Partial Least Squares (PLS) regression models for the two photosynthesis traits V cmax,25 and Jmax,25 as well as Narea and LMA were studied using a cross-validation approach. Analyses of linear regression models based on Narea and other leaf traits estimated via PROSPECT inversion, PLS regression coefficients and model residuals were conducted in order to reveal the mechanisms behind the reflectance-based estimation. We found that V cmax,25 and Jmax,25 can be estimated from leaf reflectance with good to moderate accuracy for a large number of species and different light conditions. The dominant mechanism behind the estimations was the strong relationship between photosynthesis traits and leaf nitrogen content. This was concluded from very strong relationships between PLS regression coefficients, the model residuals as well as the prediction performance of Narea- based linear regression models compared to PLS regression models. While the PLS regression model for V cmax,25

  4. Leaf traits are good predictors of plant performance across 53 rain forest species

    NARCIS (Netherlands)

    Poorter, L.; Bongers, F.J.J.M.

    2006-01-01

    We compared the leaf traits and plant performance of 53 co-occurring tree species in a semi-evergreen tropical moist forest community. The species differed in all leaf traits analyzed: leaf life span varied 11-fold among species, specific leaf area 5-fold, mass-based nitrogen 3-fold, mass-based assi

  5. The action spectrum in chloroplast translocation in multilayer leaf cells

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    Zbigniew Lechowski

    2015-01-01

    Full Text Available By measurement of light transmittance through a leaf as criterion of chloroplast translocation, the action spectrum of Ajuga reptans was established. In the spectrum obtained, a correction was introduced for leaf autoabsorption calculated on the basis of the Beer-Lambert law. The action spectrum has two maxima: at λ= 375 nm and λ= 481 nm. The range above 502 nm has no significant effect on chloroplast translocation. Comparison with other objects examined demonstrated that in multilayer leaf cells riboflavin seems also to be a photoreceptor active in this process.

  6. A second dimension to the leaf economics spectrum predicts edaphic habitat association in a tropical forest.

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    Jennifer L Baltzer

    Full Text Available BACKGROUND: Strong patterns of habitat association are frequent among tropical forest trees and contribute to the maintenance of biodiversity. The relation of edaphic differentiation to tradeoffs among leaf functional traits is less clear, but may provide insights into mechanisms of habitat partitioning in these species rich assemblages. METHODOLOGY/PRINCIPAL FINDINGS: We quantify the leaf economics spectrum (LES for 16 tree species within a Bornean forest characterized by highly pronounced habitat specialization. Our findings suggest that the primary axis of trait variation in light-limited, lowland tropical forests was identical to the LES and corresponds with the shade tolerance continuum. There was no separation with respect to edaphic variation along this primary axis of trait variation. However, a second orthogonal axis determined largely by foliar P concentrations resulted in a near-perfect separation of species occupying distinct soil types within the forest. CONCLUSIONS/SIGNIFICANCE: We suggest that this second axis of leaf trait variation represents a "leaf edaphic habitat spectrum" related to foliar P and potentially other nutrients closely linked to geological substrate, and may generally occur in plant communities characterized by strong edaphic resource gradients.

  7. Desirable leaf traits for hydrological reinforcement of soil

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    Boldrin D.

    2016-01-01

    Full Text Available Vegetation has an important influence on slope hydrology and hence slope stability via plant transpiration. Little is known about the relative merit of evergreen versus deciduous shrubs in maintaining suctions through the year. This study aims to quantify the soil-plant-water relations of two shrub species and to identify relevant plant traits that correlate with hydro-mechanical properties of vegetated soil. Corylus avellana L. (Hazel and Ilex aquifolium L. (Holly were chosen as contrasting deciduous and evergreen broadleaf species. For each species, three replicates were planted in separated pots of sandy loam soil. Each pot was irrigated until the soil was saturated and then was left to transpire for 20 days. Soil suction, leaf conductance to water vapour (gL and soil penetration resistance were recorded. After testing, some key plant traits were determined. It was found that Hazel dried soil faster than Holly. The mean suction induced by Hazel (82.9±1.5 kPa was 2.7 times greater than that induced by Holly (30.6±8.2 kPa, as Hazel has significantly higher gL and specific leaf area. Both suction and soil penetration resistance were strongly correlated with the total leaf area, but not the total leaf biomass.

  8. Temporal dynamics and leaf trait variability in Neotropical dry forests

    Science.gov (United States)

    Hesketh, Michael Sean

    This thesis explores the variability of leaf traits resulting from changes in season, ecosystem successional stage, and site characteristics. In chapter two, I present a review of the use of remote sensing analysis for the evaluation of Neotropical dry forests. Here, I stress the conclusion, drawn from studies on land cover characterization, biodiversity assessment, and evaluation of forest structural characteristics, that addressing temporal variability in spectral properties is an essential element in the monitoring of these ecosystems. Chapter three describes the effect of wet-dry seasonality on spectral classification of tree and liana species. Highly accurate classification (> 80%) was possible using data from either the wet or dry season. However, this accuracy decreased by a factor of ten when data from the wet season was classified using an algorithm trained on the dry, or vice versa. I also address the potential creation of a spectral taxonomy of species, but found that any clustering based on spectral properties resulted in markedly different arrangements in the wet and dry seasons. In chapter 4, I address the variation present in both physical and spectral leaf traits according to changes in forest successional stage at dry forest sites in Mexico and Costa Rica. I found significant differences in leaf traits between successional stages, but more strongly so in Costa Rica. This variability deceased the accuracy of spectral classification of tree species by a factor of four when classifying data using an algorithm trained on a different successional stage. Chapter 5 shows the influence of seasonality and succession on trait variability in Mexico. Differences in leaf traits between successional stages were found to be greater during the dry season, but were sufficient in both seasons to negatively influence spectral classification of tree species. Throughout this thesis, I show clear and unambiguous evidence of the variability of key physical and spectral

  9. Intraspecific growth and functional leaf trait responses to natural soil resource gradients for conifer species with contrasting leaf habit.

    Science.gov (United States)

    Walters, Michael B; Gerlach, John P

    2013-03-01

    Interspecific relationships among species mean leaf traits, performance and species resource/climate distributions help provide the foundation for a predictive, functionally based plant ecology. Intraspecific responses of leaf traits and performance to resource gradients and how these vary among species may be equally important but have received less attention. Here, we examine relationships between proxies of soil resource availability, leaf traits and growth (height at 25 years, SI25) for winter deciduous Larix decidua Mill. and evergreen Pinus resinosa Ait. trees distributed over soil resource gradients in the Great Lakes region of North America. We predicted that (i) leaf trait responses to soil resources within species will be similar to reported distributions of mean leaf traits over soil resource gradients among species; (ii) soil resource-related variation in leaf traits can help explain SI25; and (iii) SI25 will be greater for Larix than Pinus at higher soil resources and greater for Pinus than Larix at lower soil resources and this pattern will be associated with species differences in leaf trait responses to soil resources. Among the measured leaf traits (live N, Mg, Ca, K, P, and Mn, litter N, N resorption, carbon isotope discrimination, specific leaf area, lifespan), soil resources only impacted live and litter N for both species and K for Pinus. In turn, only the leaf traits responsive to soil resources affected SI25 in the expected manner. Larix had greater SI25 than Pinus across soil resource gradients and both species had similar growth and leaf trait sensitivities to resources. In summary: (i) several leaf traits reported to be associated with performance and edaphic distributions across species were, within species, unresponsive to nitrogen and water availability and unrelated to growth; (ii) leaf N showed high plasticity to soil resources and this plasticity was functionally relevant to growth over its entire range of response; (iii) large

  10. Combined use of leaf size and economics traits allows direct comparison of hydrophyte and terrestrial herbaceous adaptive strategies

    Science.gov (United States)

    Pierce, Simon; Brusa, Guido; Sartori, Matteo; Cerabolini, Bruno E. L.

    2012-01-01

    Background and Aims Hydrophytes generally exhibit highly acquisitive leaf economics. However, a range of growth forms is evident, from small, free-floating and rapidly growing Lemniden to large, broad-leaved Nymphaeiden, denoting variability in adaptive strategies. Traits used to classify adaptive strategies in terrestrial species, such as canopy height, are not applicable to hydrophytes. We hypothesize that hydrophyte leaf size traits and economics exhibit sufficient overlap with terrestrial species to allow a common classification of plant functional types, sensu Grime's CSR theory. Methods Leaf morpho-functional traits were measured for 61 species from 47 water bodies in lowland continental, sub-alpine and alpine bioclimatic zones in southern Europe and compared against the full leaf economics spectrum and leaf size range of terrestrial herbs, and between hydrophyte growth forms. Key Results Hydrophytes differed in the ranges and mean values of traits compared with herbs, but principal components analysis (PCA) demonstrated that both groups shared axes of trait variability: PCA1 encompassed size variation (area and mass), and PCA2 ranged from relatively dense, carbon-rich leaves to nitrogen-rich leaves of high specific leaf area (SLA). Most growth forms exhibited trait syndromes directly equivalent to herbs classified as R adapted, although Nymphaeiden ranged between C and SR adaptation. Conclusions Our findings support the hypothesis that hydrophyte adaptive strategy variation reflects fundamental trade-offs in economics and size that govern all plants, and that hydrophyte adaptive strategies can be directly compared with terrestrial species by combining leaf economics and size traits. PMID:22337079

  11. Do Individuals with Autism Spectrum Disorders Infer Traits from Behavior?

    Science.gov (United States)

    Ramachandran, Rajani; Mitchell, Peter; Ropar, Danielle

    2009-01-01

    Background: Traits and mental states are considered to be inter-related parts of theory of mind. Attribution research demonstrates the influential role played by traits in social cognition. However, there has been little investigation into how individuals with autism spectrum disorders (ASD) understand traits. Method: The ability of individuals…

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

    Science.gov (United States)

    Hajek, Peter; Hertel, Dietrich; Leuschner, Christoph

    2013-01-01

    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.

  13. Accumulation of three different sizes of particulate matter on plant leaf surfaces: Effect on leaf traits

    Directory of Open Access Journals (Sweden)

    Chen Xiaoping

    2015-01-01

    Full Text Available Plants not only improve air quality by adsorbing particulate matter (PM on leaf surfaces but can also be affected by their accumulation. In this study, a field investigation was performed in Wuhan, China, into the relationship between seven leaf traits and the accumulation of three different sizes of PM (PM11, PM2.5 and PM0.2 on leaves. The retention abilities of plant leaves with respect to the three sizes of PM differed significantly at different sites and species. The average PM retention capabilities of plant leaves and specific leaf area (SLA were significantly greater in a seriously polluted area, whereas the average values of chlorophyll a (Chl a, chlorophyll b (Chl b, total chlorophyll, carotenoid, pH and relative water content (RWC were greater at the control site. SLA significantly positively correlated with the size of PM, but Chl a, Chl b, total chlorophyll, RWC significantly negatively correlated with the size of PM, whereas the pH did not correlate significantly with the the PM fractions. Additionally, SLA was found to be affected by large particles (PM11, p<0.01; PM2.5 had a more obvious effect on plant leaf traits than the other PM (p<0.05. Overall, the findings from this study provide useful information regarding the selection of plants to reduce atmospheric pollution.

  14. High-Throughput Phenotyping of Maize Leaf Physiological and Biochemical Traits Using Hyperspectral Reflectance1[OPEN

    Science.gov (United States)

    Yendrek, Craig R.; Tomaz, Tiago; Montes, Christopher M.; Cao, Youyuan; Morse, Alison M.; Brown, Patrick J.; McIntyre, Lauren M.; Leakey, Andrew D.B.

    2017-01-01

    High-throughput, noninvasive field phenotyping has revealed genetic variation in crop morphological, developmental, and agronomic traits, but rapid measurements of the underlying physiological and biochemical traits are needed to fully understand genetic variation in plant-environment interactions. This study tested the application of leaf hyperspectral reflectance (λ = 500–2,400 nm) as a high-throughput phenotyping approach for rapid and accurate assessment of leaf photosynthetic and biochemical traits in maize (Zea mays). Leaf traits were measured with standard wet-laboratory and gas-exchange approaches alongside measurements of leaf reflectance. Partial least-squares regression was used to develop a measure of leaf chlorophyll content, nitrogen content, sucrose content, specific leaf area, maximum rate of phosphoenolpyruvate carboxylation, [CO2]-saturated rate of photosynthesis, and leaf oxygen radical absorbance capacity from leaf reflectance spectra. Partial least-squares regression models accurately predicted five out of seven traits and were more accurate than previously used simple spectral indices for leaf chlorophyll, nitrogen content, and specific leaf area. Correlations among leaf traits and statistical inferences about differences among genotypes and treatments were similar for measured and modeled data. The hyperspectral reflectance approach to phenotyping was dramatically faster than traditional measurements, enabling over 1,000 rows to be phenotyped during midday hours over just 2 to 4 d, and offers a nondestructive method to accurately assess physiological and biochemical trait responses to environmental stress. PMID:28049858

  15. Quantitative Trait Loci Mapping of Leaf Morphological Traits and Chlorophyll Content in Cultivated Tetraploid Cotton

    Institute of Scientific and Technical Information of China (English)

    Xian-Liang SONG; Wang-Zhen GUO; Zhi-Guo HAN; Tian-Zhen ZHANG

    2005-01-01

    Genetic mapping provides a powerful tool for quantitative trait loci (QTL) analysis at the molecular level. A simple sequence repeat (SSR) genetic map containing 590 markers and a BC1 population from two cultivated tetraploid cotton (Gossypium hirsutum L.) cultivars, namely TM-1 and Hai 7124 (G.barbadense L.), were used to map and analyze QTL using the composite interval mapping (CIM) method.Thirty one QTLs, 10 for lobe length, 13 for lobe width, six for lobe angle, and two for leaf chlorophyll content,were detected on 15 chromosomes or linkage groups at logarithm of odds (LOD) ≥ 2.0, of which 15 were found for leaf morphology at LOD ≥.3.0. The genetic effects of the QTL were estimated. These results are fundamental for marker-assisted selection (MAS) of these traits in tetraploid cotton breeding.

  16. Diurnal Leaf Starch Content: An Orphan Trait in Forage Legumes

    Directory of Open Access Journals (Sweden)

    Michael E. Ruckle

    2017-02-01

    Full Text Available Forage legumes have a relatively high biomass yield and crude protein content, but their grazed and harvested biomass lacks the high-energy carbohydrates required to meet the productivity potential of modern livestock breeds. Because of their low carbohydrate content, forage legume diets are typically supplemented with starch rich cereal grains or maize (Zea mays, leading to the disruption of local nutrient cycles. Although plant leaves were first reported to accumulate starch in a diurnal pattern over a century ago, leaf starch content has yet to be exploited as an agronomic trait in forage crops. Forage legumes such as red clover (Trifolium pratense have the genetic potential to accumulate up to one third of their leaf dry mass as starch, but this starch is typically degraded at night to support nighttime growth and respiration. Even when diurnal accumulation is considered with regard to the time the crop is harvested, only limited gains are realized due to environmental effects and post-harvest losses from respiration. Here we present original data for starch metabolism in red clover and place it in the broader context of other forage legumes such as, white clover (T. repens, and alfalfa (Medicago sativa. We review the application of recent advances in molecular breeding, plant biology, and crop phenotyping, to forage legumes to improve and exploit a potentially valuable trait for sustainable ruminant livestock production.

  17. Between-clone, between-leaf and within-leaf variation in leaf epidermis traits in Iris pumila clones

    Directory of Open Access Journals (Sweden)

    Miljković Danijela

    2013-01-01

    Full Text Available The goal of this study was to analyze variation and covariation in epidermal characteristics (epidermal cell density -ECD, stomata density - SD, and stomata index - SI on Iris pumila clones on between-clone, between-leaf and within-leaf levels. ECD (similar to the pattern previously observed for SD increased from the base to the top of leaf, while SI remained constant. Results of profile analyses indicated that clones, individual plants whitin clones (ramets, and three successive leaves on the same plant were not significantly different for examined characteristics, but genetic variation for position effect was detected (significant Zone x clone interaction. Results of the contrast analysis confirmed differences between the base and middle leaf positions for ECD (similar to those for SD as well as between clone variation for those differences. Observed differences between leaf zones and correlations between analyzed traits were mostly consistent with the expansion hypothesis of stomata differentiation. [Projekat Ministarstva nauke Republike Srbije, br. OI 173025

  18. Leaf morphological and anatomical traits from tropical to temperate coniferous forests: Mechanisms and influencing factors.

    Science.gov (United States)

    Tian, Miao; Yu, Guirui; He, Nianpeng; Hou, Jihua

    2016-01-22

    Leaf traits may reflect the adaptation mechanisms of plants to the environment. In this study, we investigated leaf morphological and anatomical traits in nine cold-temperate to tropical forests along a 4,200-km transect to test how they vary across latitudinal gradients. The results showed that leaf dry weight decreased (P < 0.05), while specific leaf area (SLA) increased (P < 0.05) with increasing latitude. Stomatal length and stomatal density did not change significantly, while stomatal pore area index increased (P < 0.05) with increasing latitude. The palisade-leaf mesophyll thickness ratio increased (P < 0.01), while the spongy-leaf mesophyll thickness ratio decreased, with increasing latitude (P < 0.01). Climate and leaf nutrients were the main factors that regulated leaf morphological and anatomical traits. Furthermore, we identified positive correlations between leaf area and leaf dry weight, leaf thickness and palisade mesophyll thickness, but negative correlations between stomatal length and stomatal density (all P < 0.01). The observed negative correlations represented the adaptive mechanisms of leaves through their morphological and anatomical traits. These findings provided new insights into the responses of leaf morphological and anatomical traits to climate changes and important parameters for future model optimization.

  19. Quantitative trait loci mapping for leaf length and leaf width in rice cv. IR64 derived lines.

    Science.gov (United States)

    Farooq, Muhammad; Tagle, Analiza G; Santos, Rizza E; Ebron, Leodegario A; Fujita, Daisuke; Kobayashi, Nobuya

    2010-06-01

    The present study was conducted to identify quantitative trait loci (QTLs) for leaf size traits in IR64 introgression lines (INLs). For this purpose, selected F(2) populations derived from crosses between recurrent parent IR64 and its derived INLs, unique for leaf length and leaf width, were used to confirm QTLs. A total of eight QTLs, mapped on three chromosomes, were identified for the four leaf size traits in six F(2) populations. A QTL for leaf length, qLLnpt-1, in HKL69 was identified around simple sequence repeat (SSR) marker RM3709 on chromosome 1. Two QTLs for flag leaf length, qFLLnpt-2 and qFLLnpt-4, in HFG39 were indentified on chromosomes 2 and 4, respectively. For flag leaf width, a QTL, qFLWnpt-4, in HFG39 was identified around RM17483 on chromosome 4. While another QTL for flag leaf width, qFLWnpt-1, in HFG27 was identified around RM3252 on chromosome 1. A QTL for leaf width, qLWnpt-2, in HKL75 was identified around RM7451 on chromosome 2. For leaf width, two QTLs, qLWnpt-4a, qLWnpt-4b, in HKL48 and HKL99 were identified around RM7208 and RM6909, respectively on chromosome 4. Results from this study suggest the possibilities to use marker-assisted selection and pyramiding these QTLs to improve rice water productivity.

  20. Size-dependent changes in leaf and wood chemical traits in two Caribbean rainforest trees.

    Science.gov (United States)

    Martin, Adam R; Thomas, Sean C

    2013-12-01

    Tree functional traits and their link to patterns of growth and demography are central to informing trait-based analyses of forest communities, and mechanistic models of forest dynamics. However, few data are available on how functional traits in trees vary through ontogeny, particularly in tropical species; and less is known about how patterns of size-dependent changes in traits may differ across species of contrasting life-history strategies. Here we describe size-dependent variation in seven leaf functional traits and four wood chemical traits, in two Dominican rainforest tree species (Dacryodes excelsa Vahl. and Miconia mirabilis (Aubl.) L.O. Williams), ranging from small saplings to the largest canopy trees. With one exception, all traits showed pronounced variation with tree size (diameter at breast height, DBH). Leaf mass per area (LMA), thickness and tissue density increased monotonically with DBH in both species. Leaf area, leaf nitrogen (N) and carbon (C) : nitrogen (N) ratios also varied significantly with DBH; however, these patterns were unimodal, with peak trait values preceding the DBH at reproductive onset in both species. Size-dependent changes in leaf structural traits (LMA and leaf thickness) were generally similar in both species, while traits associated with leaf-level investment in C gain (leaf area, leaf C : N ratio) showed contrasting ontogenetic trends between species. Wood starch concentration varied with DBH in both species, also showing unimodal patterns with peaks preceding size at reproductive onset. Wood C concentration increased linearly with DBH in both species, though significantly only in M. mirabilis. Size-dependent patterns in wood chemical traits were similar between both species. Our data demonstrate pronounced variation in functional traits through tree ontogeny, probably due to a combination of environmental factors and shifts in resource allocation. Such ontogenetic variation is comparable in magnitude with interspecific

  1. Photosynthetic responses to leaf surface wetness in tropical plant species of Costa Rica with varying leaf traits

    Science.gov (United States)

    Aparecido, L. M. T.; Moore, G. W.; Miller, G. R.; Cahill, A. T.

    2015-12-01

    Wet tropical forests are some of the environments with the greatest annual precipitation, but are also considered as the world's major carbon sink; however, literature postulates that phothsynthesis rates are inhibited while leaves are wet. Yet measurements of photosynthesis during wet conditions are challenging to obtain due to equipment limitations and the extreme complexity of canopy-atmosphere interactions in tropical environments. The objective of this study was to evaluate tropical species reactions to simulated leaf wetness and test the hypothesis that leaf wetness reduces rates of photosynthesis. In a central Costa Rica site with an average 4200 mm annual rainfall, we selected six tropical species with distinct leaf traits in which five sun-exposed leaf replicates from each species were subjected to gas exchange measurements using a LI-6400 IRGA (LICOR Inc., Lincoln, NE) under dry and wet/misted leaf conditions. Relationships between photosynthesis (As) and stomatal conductance (gs) with leaf to air temperature difference (DT), VPD, and relative humidity were evaluated using linear regression analysis. We found that the responses varied greatly among species, but all plants maintained a baseline of activity under wet leaf conditions, suggesting that abaxial leaf As was a significant percentage of total leaf As. Stachytarpheta jamaicens had an 18.7% reduction in As, while others, like Zamia skinneri, had a 7% increase in As. Tibouchina heteromalla showed a rapid stomatal recovery of 2 mins, while Carapa guianensis was slower with 7 mins. This variability between species suggests that leaf traits, such as presence or absence of trichomes, water repellency, vein distribution and size and leaf angle variation, may be critical for optimizing photosynthesis under wet conditions. Relative humidity and leaf temperature were the strongest secondary influences on As and gs under wet leaf conditions. While tropical vegetation-atmosphere interactions are complex, such

  2. Exotic or not, leaf trait dissimilarity modulates the effect of dominant species on mixed litter decomposition

    NARCIS (Netherlands)

    Finerty, Genevieve E.; de Bello, Francesco; Bílá, Karolína; Berg, Matty P.; Dias, André T C; Pezzatti, Gianni B.; Moretti, Marco

    2016-01-01

    It has long been recognized that leaf traits exert a crucial control on litter decomposition, a key process for nutrient cycling, and that invading species can greatly alter such soil processes via changes in mixed litter trait composition. Trait effects on ecosystem processes are hypothesized to op

  3. Modeling development and quantitative trait mapping reveal independent genetic modules for leaf size and shape.

    Science.gov (United States)

    Baker, Robert L; Leong, Wen Fung; Brock, Marcus T; Markelz, R J Cody; Covington, Michael F; Devisetty, Upendra K; Edwards, Christine E; Maloof, Julin; Welch, Stephen; Weinig, Cynthia

    2015-10-01

    Improved predictions of fitness and yield may be obtained by characterizing the genetic controls and environmental dependencies of organismal ontogeny. Elucidating the shape of growth curves may reveal novel genetic controls that single-time-point (STP) analyses do not because, in theory, infinite numbers of growth curves can result in the same final measurement. We measured leaf lengths and widths in Brassica rapa recombinant inbred lines (RILs) throughout ontogeny. We modeled leaf growth and allometry as function valued traits (FVT), and examined genetic correlations between these traits and aspects of phenology, physiology, circadian rhythms and fitness. We used RNA-seq to construct a SNP linkage map and mapped trait quantitative trait loci (QTL). We found genetic trade-offs between leaf size and growth rate FVT and uncovered differences in genotypic and QTL correlations involving FVT vs STPs. We identified leaf shape (allometry) as a genetic module independent of length and width and identified selection on FVT parameters of development. Leaf shape is associated with venation features that affect desiccation resistance. The genetic independence of leaf shape from other leaf traits may therefore enable crop optimization in leaf shape without negative effects on traits such as size, growth rate, duration or gas exchange.

  4. Facilitation promotes changes in leaf economics traits of a perennial forb.

    Science.gov (United States)

    García-Cervigón, Ana I; Linares, Juan Carlos; Aibar, Pablo; Olano, José M

    2015-09-01

    Optimal allocation of resources is crucial to maximize plant success. Plants modify their economic strategies by adjusting functional traits in response to shifts in environmental conditions. Facilitation has been recognized as a major biotic filter of trait distribution in communities, although the effect of facilitation on intraspecific variability has been scarcely explored. We evaluated intraspecific shifts in leaf functional traits of a perennial forb (Helleborus foetidus) in relation to the presence of a nurse plant (Juniperus sabina) in two sites with contrasting abiotic stress levels. The effects of abiotic (site) and biotic (juniper presence, microsite) environments on specific leaf area (SLA), leaf area (LA), lamina/petiole length ratio (LPR), intrinsic water use efficiency (iWUE) and leaf nutrient content (N, P and N:P) per mass were evaluated. Alleviation of drought stress associated with nurse plant presence was reflected in SLA, LA, LPR and iWUE at the high-stress site. Individuals growing in open areas showed more resource-conservative traits, supporting the argument that this strategy is advantageous in environments that limit opportunities for rapid carbon gain. Leaf nutrients were unrelated to other traits. The large amount of intraspecific variation in leaf functional traits related to facilitative processes highlights the importance of facilitation as a major source of plant trait variation. Both positive and negative biotic interactions, as well as intraspecific trait variability, should be considered in mechanistic models of plant communities' functional responses to environmental changes.

  5. Variation in leaf wettability traits along a tropical montane elevation gradient.

    Science.gov (United States)

    Goldsmith, Gregory R; Bentley, Lisa Patrick; Shenkin, Alexander; Salinas, Norma; Blonder, Benjamin; Martin, Roberta E; Castro-Ccossco, Rosa; Chambi-Porroa, Percy; Diaz, Sandra; Enquist, Brian J; Asner, Gregory P; Malhi, Yadvinder

    2017-05-01

    Leaf wetting is often considered to have negative effects on plant function, such that wet environments may select for leaves with certain leaf surface, morphological, and architectural traits that reduce leaf wettability. However, there is growing recognition that leaf wetting can have positive effects. We measured variation in two traits, leaf drip tips and leaf water repellency, in a series of nine tropical forest communities occurring along a 3300-m elevation gradient in southern Peru. To extend this climatic gradient, we also assembled published leaf water repellency values from 17 additional sites. We then tested hypotheses for how these traits should vary as a function of climate. Contrary to expectations, we found that the proportion of species with drip tips did not increase with increasing precipitation. Instead, drip tips increased with increasing temperature. Moreover, leaf water repellency was very low in our sites and the global analysis indicated high repellency only in sites with low precipitation and temperatures. Our findings suggest that drip tips and repellency may not solely reflect the negative effects of wetting on plant function. Understanding the drivers of leaf wettability traits can provide insight into the effects of leaf wetting on plant, community, and ecosystem function. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  6. Leaf Chemical and Structural Traits Control Variation in Leaf Litter Water Absorption

    Science.gov (United States)

    Talhelm, A. F.; Smith, A. M.

    2016-12-01

    The ability of plant litter to absorb moisture from precipitation or atmospheric humidity is well known to vary among plant species and is an important trait for wildland fire science, hydrology, and litter decomposition. This variation among species is thought to be function of litter physical and chemical traits, but there has been little systematic investigation of these relationships. To test the influence of chemical and structural traits on water absorption, we collected recently senesced leaves of 23 temperate species that represented a range of habitats and plant functional types and then quantified a suite of biochemical (gross energy, lignin, lipid, and ash content), elemental (C, N, O, and H %, C oxidation state), and structural (specific leaf area) characteristics as well as the maximum water absorption capacity of whole leaves and the amount of water vapor absorbed by whole leaves and finely-ground leaves. Maximum water absorption of whole leaves was positively related to both average C oxidation state (r = 0.55) and specific leaf area (r = 0.58) and negatively related to lignin (r = -0.67) and energy content (r = -0.57). The amount water vapor absorbed over an hour after being removed from a drying oven for whole leaves and ground leaves was positively correlated with tissue C oxidation state (r = 0.63, r = 0.53, respectively) and energy content (r = 0.41, r = 0.48). Because moist fuels release less energy when burned, our observation that litter energy content is linked to moisture absorption represents a mechanism that widens the gap between comparatively flammable and non-flammable species. Also, because lignin and lipid content were each positively correlated with energy content (r > 0.66) and negatively correlated with C oxidation state (r traits in water absorption could be used to help predict shifts in ecosystem function as plant communities reassemble as result of climate change. The views expressed in this work are those of the authors and

  7. Natural Variation of Leaf Thickness and Its Association to Yield Traits in indica Rice

    Institute of Scientific and Technical Information of China (English)

    LIU Chuan-guang; ZHOU Xin-qiao; CHEN Da-gang; LI Li-jun; LI Ju-chang; CHEN You-ding

    2014-01-01

    Leaf thickness is an important morphological trait in rice. Its association to the yield potential, as of now has not been documented because of the shortage of the equipment which could conveniently measure the leaf thickness in rice. In this study, the thickness of top three leaves of 208 cultivars had been determined by a nondestructive rice leaf thickness instrument for the research of the natural variation of leaves thickness and its association to yield traits inindica rice. The results showed that the lfag leaf was the thickest, and the 2nd leaf was thicker than the 3rd leaf. Analysis of variance indicated the existence of wide genetic diversity of leaf thickness among the investigatedindica rice genotypes. The tight correlation among the thicknesses of the top three leaves means that the leaf thickness traits share one genetic control system. Leaf thickness had a signiifcant positive correlation with leaf length and a positive correlation with leaf width, indicated that thicker leaf was beneifcial to increasing the single leaf area. The results of correlation analysis revealed that thicker leaf should be proiftable to the leaf erection, higher numbers of grains per panicle and higher grains weight per panicle. However, the signiifcantly negative correlation between leaf thickness and number of panicles per plant counteracted the proiftability from increased grains weight per panicle, so that the correlations of the thicknesses of the top three leaves to yield and biomass were positive but not signiifcantly. It has made great progress in the genetic improvement of leaves thickness in inbredindica rice breeding in Guangdong Province, China, since the 1990s.

  8. Predicting tree water use and drought tolerance from leaf traits in the Los Angeles urban ecosystem

    Science.gov (United States)

    John, G. P.; Scoffoni, C.; Sack, L.

    2013-12-01

    Urban green space provides a suite of valuable ecosystem services. In semiarid systems, like Los Angeles, trees rely primarily on irrigation water for transpiration. Managers may need to reduce irrigation associated with urban trees given climate change, urban expansion, and the steady decrease in available freshwater. While leaf and whole plant water relations have been extensively studied, we are only now gaining a detailed understanding of diverse leaf anatomical designs, and their use for predicting physiology and water use at landscape scale. For 50 diverse urban species, we quantified leaf anatomical and physiological traits important to tree drought tolerance and water use efficiency including turgor loss point, vein architecture, cellular anatomy, leaf mass per unit area, and petiole and leaf dimensions. We hypothesized detailed relationships to develop models relating leaf functional traits to tree water relations. These models provide key insights regarding the role of anatomical designs in leaf stress tolerance and water use efficiency. Additionally we predicted how traits measured at the leaf level would scale with existing data for individuals at the whole plant level. We tested our predictions by determining correlations between leaf level anatomical traits and drought tolerance. Additionally, we determined correlations between functional traits, physiology and water use, and the climate of origin for the urban species. Leaf level measurements will be valuable for rapid estimation of more difficult to measure whole plant water relations traits important at the landscape scale. The Los Angeles urban ecosystem can serve as a model for other semiarid system and provide more informed system wide water conservation strategies.

  9. Simple sequence repeat marker associated with a natural leaf defoliation trait in tetraploid cotton.

    Science.gov (United States)

    Abdurakhmonov, I Y; Abdullaev, A A; Saha, S; Buriev, Z T; Arslanov, D; Kuryazov, Z; Mavlonov, G T; Rizaeva, S M; Reddy, U K; Jenkins, J N; Abdullaev, A; Abdukarimov, A

    2005-01-01

    Cotton (Gossypium hirsutum L.) leaf defoliation has a significant ecological and economical impact on cotton production. Thus the utilization of a natural leaf defoliation trait, which exists in wild diploid cotton species, in the development of tetraploid cultivated cotton will not only be cost effective, but will also facilitate production of very high-grade fiber. The primary goal of our research was to tag loci associated with natural leaf defoliation using microsatellite markers in Upland cotton. The F2 populations developed from reciprocal crosses between the two parental cotton lines--AN-Boyovut-2 (2n = 52), a late leaf defoliating type, and Listopad Beliy (2n = 52), a naturally early leaf defoliating type--demonstrated that the naturally early leaf defoliation trait has heritability values of 0.74 and 0.84 in the reciprocal F2 population. The observed phenotypic segregation difference in reciprocal crosses suggested a minor cytoplasmic effect in the phenotypic expression of the naturally early leaf defoliation trait. Results from the Kruskal-Wallis (KW) nonparametric test revealed that JESPR-13 (KW = 6.17), JESPR-153 (KW = 9.97), and JESPR-178 (KW = 13.45) Simple sequence repeat (SSR) markers are significantly associated with natural leaf defoliation in the mapping population having stable estimates at empirically obtained critical thresholds (P < .05-.0001). JESPR-178 revealed the highest estimates (P < .0001) for association with the natural leaf defoliation trait, exceeding maximum empirical threshold values. JESPR-178 was assigned to the short arm of chromosome 18, suggesting indirectly that genes associated with natural leaf defoliation might be located on this chromosome. This microsatellite marker may have the potential for use to introgress the naturally early leaf defoliation quantitative trait loci (QTL) from the donor line Listopad Beliy to commercial varieties of cotton through marker-assisted selection programs.

  10. Correlated evolution of stem and leaf hydraulic traits in Pereskia (Cactaceae).

    Science.gov (United States)

    Edwards, Erika J

    2006-01-01

    Recent studies have demonstrated significant correlations between stem and leaf hydraulic properties when comparing across species within ecological communities. This implies that these traits are co-evolving, but there have been few studies addressing plant water relations within an explicitly evolutionary framework. This study tests for correlated evolution among a suite of plant water-use traits and environmental parameters in seven species of Pereskia (Cactaceae), using phylogenetically independent contrasts. There were significant evolutionary correlations between leaf-specific xylem hydraulic conductivity, Huber Value, leaf stomatal pore index, leaf venation density and leaf size, but none of these traits appeared to be correlated with environmental water availability; only two water relations traits - mid-day leaf water potentials and photosynthetic water use efficiency - correlated with estimates of moisture regime. In Pereskia, it appears that many stem and leaf hydraulic properties thought to be critical to whole-plant water use have not evolved in response to habitat shifts in water availability. This may be because of the extremely conservative stomatal behavior and particular rooting strategy demonstrated by all Pereskia species investigated. These results highlight the need for a lineage-based approach to understand the relative roles of functional traits in ecological adaptation.

  11. Light-dependent leaf trait variation in 43 tropical dry forest tree species

    NARCIS (Netherlands)

    Markesteijn, L.; Poorter, L.; Bongers, F.J.J.M.

    2007-01-01

    Our understanding of leaf acclimation in relation to irradiance of fully grown or juvenile trees is mainly based on research involving tropical wet forest species. We studied sun¿shade plasticity of 24 leaf traits of 43 tree species in a Bolivian dry deciduous forest. Sampling was confined to small

  12. Differences in leaf flammability, leaf traits and flammability-trait relationships between native and exotic plant species of dry sclerophyll forest.

    Science.gov (United States)

    Murray, Brad R; Hardstaff, Lyndle K; Phillips, Megan L

    2013-01-01

    The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dry-leaf flammability (time to ignition) between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignition was significantly faster in dry exotic leaves than in dry native leaves. There was no significant native-exotic difference in mean time to ignition for fresh leaves. The significantly higher fresh-leaf water content that was found in exotics, lost in the conversion from a fresh to dry state, suggests that leaf water provides an important buffering effect that leads to equivalent mean time to ignition in fresh exotic and native leaves. Exotic leaves were also significantly wider, longer and broader in area with significantly higher specific leaf area-but not thicker-than native leaves. We examined scaling relationships between leaf flammability and leaf size (leaf width, length, area, specific leaf area and thickness). While exotics occupied the comparatively larger and more flammable end of the leaf size-flammability spectrum in general, leaf flammability was significantly correlated with all measures of leaf size except leaf thickness in both native and exotic species such that larger leaves were faster to ignite. Our findings for increased flammability linked with larger leaf size in exotics demonstrate that exotic plant species have the potential to increase the spread of bushfires in dry sclerophyll forest.

  13. Differences in leaf flammability, leaf traits and flammability-trait relationships between native and exotic plant species of dry sclerophyll forest.

    Directory of Open Access Journals (Sweden)

    Brad R Murray

    Full Text Available The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dry-leaf flammability (time to ignition between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignition was significantly faster in dry exotic leaves than in dry native leaves. There was no significant native-exotic difference in mean time to ignition for fresh leaves. The significantly higher fresh-leaf water content that was found in exotics, lost in the conversion from a fresh to dry state, suggests that leaf water provides an important buffering effect that leads to equivalent mean time to ignition in fresh exotic and native leaves. Exotic leaves were also significantly wider, longer and broader in area with significantly higher specific leaf area-but not thicker-than native leaves. We examined scaling relationships between leaf flammability and leaf size (leaf width, length, area, specific leaf area and thickness. While exotics occupied the comparatively larger and more flammable end of the leaf size-flammability spectrum in general, leaf flammability was significantly correlated with all measures of leaf size except leaf thickness in both native and exotic species such that larger leaves were faster to ignite. Our findings for increased flammability linked with larger leaf size in exotics demonstrate that exotic plant species have the potential to increase the spread of bushfires in dry sclerophyll forest.

  14. Height-related changes in leaf photosynthetic traits in diverse Bornean tropical rain forest trees.

    Science.gov (United States)

    Kenzo, Tanaka; Inoue, Yuta; Yoshimura, Mitsunori; Yamashita, Megumi; Tanaka-Oda, Ayumi; Ichie, Tomoaki

    2015-01-01

    Knowledge of variations in morphophysiological leaf traits with forest height is essential for quantifying carbon and water fluxes from forest ecosystems. Here, we examined changes in leaf traits with forest height in diverse tree species and their role in environmental acclimation in a tropical rain forest in Borneo that does not experience dry spells. Height-related changes in leaf physiological and morphological traits [e.g., maximum photosynthetic rate (Amax), stomatal conductance (gs), dark respiration rate (Rd), carbon isotope ratio (δ(13)C), nitrogen (N) content, and leaf mass per area (LMA)] from understory to emergent trees were investigated in 104 species in 29 families. We found that many leaf area-based physiological traits (e.g., A(max-area), Rd, gs), N, δ(13)C, and LMA increased linearly with tree height, while leaf mass-based physiological traits (e.g., A(max-mass)) only increased slightly. These patterns differed from other biomes such as temperate and tropical dry forests, where trees usually show decreased photosynthetic capacity (e.g., A(max-area), A(max-mass)) with height. Increases in photosynthetic capacity, LMA, and δ(13)C are favored under bright and dry upper canopy conditions with higher photosynthetic productivity and drought tolerance, whereas lower R d and LMA may improve shade tolerance in lower canopy trees. Rapid recovery of leaf midday water potential to theoretical gravity potential during the night supports the idea that the majority of trees do not suffer from strong drought stress. Overall, leaf area-based photosynthetic traits were associated with tree height and the degree of leaf drought stress, even in diverse tropical rain forest trees.

  15. Coordination of Leaf Photosynthesis, Transpiration, and Structural Traits in Rice and Wild Relatives (Genus Oryza).

    Science.gov (United States)

    Giuliani, Rita; Koteyeva, Nuria; Voznesenskaya, Elena; Evans, Marc A; Cousins, Asaph B; Edwards, Gerald E

    2013-07-01

    The genus Oryza, which includes rice (Oryza sativa and Oryza glaberrima) and wild relatives, is a useful genus to study leaf properties in order to identify structural features that control CO(2) access to chloroplasts, photosynthesis, water use efficiency, and drought tolerance. Traits, 26 structural and 17 functional, associated with photosynthesis and transpiration were quantified on 24 accessions (representatives of 17 species and eight genomes). Hypotheses of associations within, and between, structure, photosynthesis, and transpiration were tested. Two main clusters of positively interrelated leaf traits were identified: in the first cluster were structural features, leaf thickness (Thick(leaf)), mesophyll (M) cell surface area exposed to intercellular air space per unit of leaf surface area (S(mes)), and M cell size; a second group included functional traits, net photosynthetic rate, transpiration rate, M conductance to CO(2) diffusion (g(m)), stomatal conductance to gas diffusion (g(s)), and the g(m)/g(s) ratio.While net photosynthetic rate was positively correlated with gm, neither was significantly linked with any individual structural traits. The results suggest that changes in gm depend on covariations of multiple leaf (S(mes)) and M cell (including cell wall thickness) structural traits. There was an inverse relationship between Thick(leaf) and transpiration rate and a significant positive association between Thick(leaf) and leaf transpiration efficiency. Interestingly, high g(m) together with high g(m)/g(s) and a low S(mes)/g(m) ratio (M resistance to CO(2) diffusion per unit of cell surface area exposed to intercellular air space) appear to be ideal for supporting leaf photosynthesis while preserving water; in addition, thick M cell walls may be beneficial for plant drought tolerance.

  16. Relationships among leaf functional traits, litter traits, and mass loss during early phases of leaf litter decomposition in 12 woody plant species.

    Science.gov (United States)

    Zukswert, Jenna M; Prescott, Cindy E

    2017-09-08

    Litter 'quality' or decomposability has historically been estimated through measuring chemical attributes, such as concentrations of nitrogen or 'lignin'. More recently, foliar functional traits, which may incorporate indications of the physical structures of tissues, have been found to correlate with litter mass loss rates. However, these traits may not be adequate to predict early rates of mass loss, in which two factors are crucial: the amount of material quickly lost through leaching, and the ease of access of decomposer organisms to the more labile tissues in the interior of the litter. We investigated relationships among physical and chemical traits in foliage and litter of 12 species native to British Columbia and then observed how these traits related to mass loss during the first 3 months (Phase I) and between 3 and 12 months (Phase II). Novel traits measured in this study include cuticle thickness, litter leaching loss, and litter water uptake. Foliar and litter traits both co-varied along spectra, but several chemical traits, such as nitrogen concentration, changed from foliage to litter, i.e., during senescence. Phase I mass loss was best predicted by leaching loss and traits relating to leaching, such as cuticle thickness and specific leaf area. Phase II mass loss was predicted by traits that may relate to decomposer access and activity, such as leaf dry matter content and foliar nitrogen. Physical traits predicted mass loss as well or better than chemical traits, suggesting that physical characteristics of litter are important in determining early rates of decomposition.

  17. C:N:P Stoichiometry and Leaf Traits of Halophytes in an Arid Saline Environment, Northwest China

    Science.gov (United States)

    Wang, Lilong; Zhao, Guanxiang; Li, Meng; Zhang, Mingting; Zhang, Lifang; Zhang, Xinfang; An, Lizhe; Xu, Shijian

    2015-01-01

    Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC), leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry) based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody) to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem. PMID:25798853

  18. C:N:P stoichiometry and leaf traits of halophytes in an arid saline environment, northwest China.

    Directory of Open Access Journals (Sweden)

    Lilong Wang

    Full Text Available Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC, leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem.

  19. C:N:P stoichiometry and leaf traits of halophytes in an arid saline environment, northwest China.

    Science.gov (United States)

    Wang, Lilong; Zhao, Guanxiang; Li, Meng; Zhang, Mingting; Zhang, Lifang; Zhang, Xinfang; An, Lizhe; Xu, Shijian

    2015-01-01

    Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC), leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry) based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody) to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem.

  20. Taxonomic identity, phylogeny, climate and soil fertility as drivers of leaf traits across Chinese grassland biomes.

    Science.gov (United States)

    He, Jin-Sheng; Wang, Xiangping; Schmid, Bernhard; Flynn, Dan F B; Li, Xuefei; Reich, Peter B; Fang, Jingyun

    2010-07-01

    Although broad-scale inter-specific patterns of leaf traits are influenced by climate, soil, and taxonomic identity, integrated assessments of these drivers remain rare. Here, we quantify these drivers in a field study of 171 plant species in 174 sites across Chinese grasslands, including the Tibetan Plateau, Inner Mongolia, and Xinjiang. General linear models were used to partition leaf trait variation. Of the total variation in leaf traits, on average 27% is due to taxonomic or phylogenetic differences among species within sites (pure species effect), 29% to variation among sites within species (pure site effect), 38% to joint effects of taxonomic and environmental factors (shared effect), and 6.2% to within-site and within-species variation. Examining the pure site effect, climate explained 7.8%, soil explained 7.4%, and climate and soil variables together accounted for 11%, leaving 18% of the inter-site variation due to factors other than climate or soil. The results do not support the hypothesis that soil fertility is the "missing link" to explain leaf trait variation unexplained by climatic factors. Climate- and soil-induced leaf adaptations occur mostly among species, and leaf traits vary little within species in Chinese grassland plants, despite strongly varying climate and soil conditions.

  1. No evidence for leaf-trait dissimilarity effects on litter decomposition, fungal decomposers, and nutrient dynamics.

    Science.gov (United States)

    Frainer, André; Moretti, Marcelo S; Xu, Wenjing; Gessner, Mark O

    2015-02-01

    Biodiversity and ecosystem-functioning theory suggest that litter mixtures composed of dissimilar leaf species can enhance decomposition due to species trait complementarity. Here we created a continuous gradient of litter chemistry trait variability within species mixtures to assess effects of litter dissimilarity on three related processes in a natural stream: litter decomposition, fungal biomass accrual in the litter, and nitrogen and phosphorus immobilization. Litter from a pool of eight leaf species was analyzed for chemistry traits affecting decomposition (lignin, nitrogen, and phosphorus) and assembled in all of the 28 possible two-species combinations. Litter dissimilarity was characterized in terms of a range of trait-diversity measures, using Euclidean and Gower distances and dendrogram-based indices. We found large differences in decomposition rates among leaf species, but no significant relationships between decomposition rate of individual leaf species and litter trait dissimilarity, irrespective of whether decomposition was mediated by microbes alone or by both microbes and litter-consuming invertebrates. Likewise, no effects of trait dissimilarity emerged on either fungal biomass accrual or changes during decomposition of nitrogen or phosphorus concentrations in individual leaf species. In line with recent meta-analyses, these results provide support for the contention that litter diversity effects on decomposition, at least in streams, are less pronounced than effects on terrestrial primary productivity.

  2. Defining leaf traits linked to yield in short-rotation coppice Salix

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, K.M.; Taylor, Gail [Southampton Univ., School of Biological Sciences, Southampton (United Kingdom); Karp, A. [Bristol Univ., Long Ashton Research Station, Dept. of Agricultural Sciences, Bristol (United Kingdom)

    2004-05-01

    Short-rotation coppice Salix genotypes of differing biomass yields were studied over two growing seasons with the long-term aim of identifying traits definitive of high yield for the breeding of elite energy crops. In the first season, basic leaf and stem traits were measured in six Salix genotypes, to identify morphological characteristics associated with high biomass yields. Thereafter, S. viminalis L. 'L78183' (low yield) and the hybrid genotype S. schwerinii E. Wolf x S. viminalis L. 'Tora' (high yield) were compared. Maximum stem heights and stem diameters increased with biomass yield. 'Tora' produced more sylleptic branches on the leading stems than 'L78183'. Leaf traits differed significantly between the two genotypes: individual leaf area and cell number per leaf was greater in 'Tora' whereas cell area was greater in 'L78183' suggesting that final leaf areas were attained in 'Tora' through the production of many, small cells, and in 'L78183' through fewer, large cells. Leaf extension rates were higher in 'Tora' than 'L78183'. This result was mirrored for leaf production rate. Leaf area index, examined at two coppice stages, was higher in 'L78183' (values of 2.06 and 1.67) than in 'Tora' (maximum value 1.43) which had a very open canopy. Furthermore, A/C{sub i} analysis revealed the low-yielding genotype as the most photosynthetically efficient at the individual leaf level whereas light response curves suggest that 'Tora' utilised light more efficiently. The results presented in this study suggest that leaf extension rate, final leaf size and cell number per leaf may be indicative of yield, and may be useful as selection criteria for potentially high-yielding hybrids for biomass use. (Author)

  3. Speech spectrum's correlation with speakers' Eysenck personality traits.

    Science.gov (United States)

    Hu, Chao; Wang, Qiandong; Short, Lindsey A; Fu, Genyue

    2012-01-01

    The current study explored the correlation between speakers' Eysenck personality traits and speech spectrum parameters. Forty-six subjects completed the Eysenck Personality Questionnaire. They were instructed to verbally answer the questions shown on a computer screen and their responses were recorded by the computer. Spectrum parameters of /sh/ and /i/ were analyzed by Praat voice software. Formant frequencies of the consonant /sh/ in lying responses were significantly lower than that in truthful responses, whereas no difference existed on the vowel /i/ speech spectrum. The second formant bandwidth of the consonant /sh/ speech spectrum was significantly correlated with the personality traits of Psychoticism, Extraversion, and Neuroticism, and the correlation differed between truthful and lying responses, whereas the first formant frequency of the vowel /i/ speech spectrum was negatively correlated with Neuroticism in both response types. The results suggest that personality characteristics may be conveyed through the human voice, although the extent to which these effects are due to physiological differences in the organs associated with speech or to a general Pygmalion effect is yet unknown.

  4. Leaf trait response to nutrients and herbivore exclusion across a globally replicated grassland experiment

    Science.gov (United States)

    Firn, Jennifer

    2017-04-01

    Leaf trait response to nutrients and herbivore exclusion across a globally replicated grassland experiment Jennifer Firn1, James McGree2, Eric Lind3, Elizabeth Borer3, Eric Seabloom3, Lauren Sullivan3, Kimberly Lapierre4 and the Nutrient Network 1Queensland University of Technology (QUT), School of Earth, Environmental and Biological Sciences, Science and Engineering Faculty, Brisbane, QLD, 4001 Australia 2Queensland University of Technology (QUT), School of Mathematical Sciences, Science and Engineering Faculty, Brisbane, QLD, 4001 Australia 3Universtiy of Minnesota, Department of Ecology, Evolution, and Behavior, 1479 Gortner Avenue, 140 Gortner Laboratory, St. Paul, MN 55108 USA 4Department of integrative Biology, University of California, Berkeley, CA 94720 USA Functional trait research has developed with the aim of finding general patterns in how the function of plant assemblages changes with respect to different land-uses. Most studies have compared sites within and across regions with variations in land-use history, but not necessarily with standardized treatments in an experimental framework. The trends that have emerged from this research is that characteristics of leaf traits such as specific leaf area (SLA) correlate with carbon acquisition strategies known to influence ecosystem functioning. SLA has been found to represent a plant's investment in growing light-capturing area per dry mass content. Species with a relatively high SLA tend to have a higher rate of return on the resources invested into making tissue (cheaper leaves in terms of energy and resources needed to produce them) when compared to species with a lower SLA (more expensive leaves to produce). Few studies have examined quantitatively measured traits in an experimental framework. The Nutrient Network experiment, globally distributed experiment, presents a unique opportunity to examine the response of functional traits across grassland ecosystems characterised by a diverse range of

  5. Reading the Leaves' Palm: Leaf Traits and Herbivory along the Microclimatic Gradient of Forest Layers.

    Science.gov (United States)

    Stiegel, Stephanie; Entling, Martin H; Mantilla-Contreras, Jasmin

    2017-01-01

    Microclimate in different positions on a host plant has strong direct effects on herbivores. But little is known about indirect effects due to changes of leaf traits. We hypothesized that herbivory increases from upper canopy to lower canopy and understory due to a combination of direct and indirect pathways. Furthermore, we hypothesized that herbivory in the understory differs between tree species in accordance with their leaf traits. We investigated herbivory by leaf chewing insects along the vertical gradient of mixed deciduous forest stands on the broad-leaved tree species Fagus sylvatica L. (European beech) with study sites located along a 140 km long transect. Additionally, we studied juvenile Acer pseudoplatanus L. (sycamore maple) and Carpinus betulus L. (hornbeam) individuals within the understory as a reference of leaf traits in the same microclimate. Lowest levels of herbivory were observed in upper canopies, where temperatures were highest. Temperature was the best predictor for insect herbivory across forest layers in our study. However, the direction was opposite to the generally known positive relationship. Herbivory also varied between the three tree species with lowest levels for F. sylvatica. Leaf carbon content was highest for F. sylvatica and probably indicates higher amounts of phenolic defense compounds. We conclude that the effect of temperature must have been indirect, whereby the expected higher herbivory was suppressed due to unfavorable leaf traits (lower nitrogen content, higher toughness and carbon content) of upper canopy leaves compared to the understory.

  6. Leaf-trait plasticity and species vulnerability to climate change in a Mongolian steppe.

    Science.gov (United States)

    Liancourt, Pierre; Boldgiv, Bazartseren; Song, Daniel S; Spence, Laura A; Helliker, Brent R; Petraitis, Peter S; Casper, Brenda B

    2015-09-01

    Climate change is expected to modify plant assemblages in ways that will have major consequences for ecosystem functions. How climate change will affect community composition will depend on how individual species respond, which is likely related to interspecific differences in functional traits. The extraordinary plasticity of some plant traits is typically neglected in assessing how climate change will affect different species. In the Mongolian steppe, we examined whether leaf functional traits under ambient conditions and whether plasticity in these traits under altered climate could explain climate-induced biomass responses in 12 co-occurring plant species. We experimentally created three probable climate change scenarios and used a model selection procedure to determine the set of baseline traits or plasticity values that best explained biomass response. Under all climate change scenarios, plasticity for at least one leaf trait correlated with change in species performance, while functional leaf-trait values in ambient conditions did not. We demonstrate that trait plasticity could play a critical role in vulnerability of species to a rapidly changing environment. Plasticity should be considered when examining how climate change will affect plant performance, species' niche spaces, and ecological processes that depend on plant community composition.

  7. Responses of leaf traits to climatic gradients: adaptive variation versus compositional shifts

    Science.gov (United States)

    Meng, T.-T.; Wang, H.; Harrison, S. P.; Prentice, I. C.; Ni, J.; Wang, G.

    2015-09-01

    Dynamic global vegetation models (DGVMs) typically rely on plant functional types (PFTs), which are assigned distinct environmental tolerances and replace one another progressively along environmental gradients. Fixed values of traits are assigned to each PFT; modelled trait variation along gradients is thus driven by PFT replacement. But empirical studies have revealed "universal" scaling relationships (quantitative trait variations with climate that are similar within and between species, PFTs and communities); and continuous, adaptive trait variation has been proposed to replace PFTs as the basis for next-generation DGVMs. Here we analyse quantitative leaf-trait variation on long temperature and moisture gradients in China with a view to understanding the relative importance of PFT replacement vs. continuous adaptive variation within PFTs. Leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC) and nitrogen content of dry matter were measured on all species at 80 sites ranging from temperate to tropical climates and from dense forests to deserts. Chlorophyll fluorescence traits and carbon, phosphorus and potassium contents were measured at 47 sites. Generalized linear models were used to relate log-transformed trait values to growing-season temperature and moisture indices, with or without PFT identity as a predictor, and to test for differences in trait responses among PFTs. Continuous trait variation was found to be ubiquitous. Responses to moisture availability were generally similar within and between PFTs, but biophysical traits (LA, SLA and LDMC) of forbs and grasses responded differently from woody plants. SLA and LDMC responses to temperature were dominated by the prevalence of evergreen PFTs with thick, dense leaves at the warm end of the gradient. Nutrient (N, P and K) responses to climate gradients were generally similar within all PFTs. Area-based nutrients generally declined with moisture; Narea and Karea declined with temperature

  8. Modulation of Leaf Economic Traits and Rates by Soil Properties, at Global Scale

    Science.gov (United States)

    Maire, V.; Wright, I. J.; Reich, P. B.; Batjes, N. H., Jr.; van Bodegom, P. M.; Bhaskar, R.; Santiago, L. S.; Ellsworth, D.; Niinemets, U.; Cornwell, W.

    2014-12-01

    Photosynthesis can be construed as an economic process that optimises the costs of acquisition, transport and utilisation of two substitutable photosynthetic resources: water and nitrogen. The influence of soil fertility on photosynthetic rates and leaf 'economic' traits related with H2O and N costs is poorly quantified in higher plants in comparison with the effects of climate. We set out to address this situation by quantifying the unique and shared contributions to global leaf-trait variation from soils and climate. Using a trait dataset comprising 1509 species from 288 sites, with climate and soil data derived from global datasets, we quantified the effects of soil and climate properties on photosynthetic traits: light-saturated photosynthetic rate (Aarea), stomatal conductance to water vapour (gs), leaf N and P (Narea and Parea) and specific leaf area (SLA). We used mixed regression models, multivariate analyses and variance partitioning. Along a first dimension of soil fertility, soil pH covaried positively with measures of base status and climatic aridity, and negatively with soil organic C content. Along this dimension from low to high soil pH, Narea, Parea and Aarea increased and SLA decreased. Along an independent dimension of soil fertility, gs declined and Parea increased with soil available P (Pavail). Overall, soil variables were stronger predictors of leaf traits than were climate variables, except for SLA. Importantly, soils and climate were not redundant information to explain leaf trait variation but were not additive either. Shared effects of soil and climate dominated over their independent effects on Narea and Parea, while unique effects of soils dominated for Aarea and gs. Three environmental variables were key for explaining variation in leaf traits: soil pH and Pavail, and climatic aridity. Although the reliability of global soils datasets lags behind that of climate datasets our results nonetheless provide compelling evidence that both can

  9. Responses of leaf traits to climatic gradients: adaptive variation vs. compositional shifts

    Directory of Open Access Journals (Sweden)

    T.-T. Meng

    2015-05-01

    Full Text Available Dynamic global vegetation models (DGVMs typically rely on plant functional types (PFTs, which are assigned distinct environmental tolerances and replace one another progressively along environmental gradients. Fixed values of traits are assigned to each PFT; modelled trait variation along gradients is thus driven by PFT replacement. But empirical studies have revealed "universal" scaling relationships (quantitative trait variations with climate that are similar within and between species, PFTs and communities; and continuous, adaptive trait variation has been proposed to replace PFTs as the basis for next-generation DGVMs. Here we analyse quantitative leaf-trait variation on long temperature and moisture gradients in China with a view to understanding the relative importance of PFT replacement vs. continuous adaptive variation within PFTs. Leaf area (LA, specific leaf area (SLA, leaf dry matter content (LDMC and nitrogen content of dry matter were measured on all species at 80 sites ranging from temperate to tropical climates and from dense forests to deserts. Chlorophyll fluorescence traits and carbon, phosphorus and potassium contents were measured at 47 sites. Generalized linear models were used to relate log-transformed trait values to growing-season temperature and moisture indices, with or without PFT identity as a predictor, and to test for differences in trait responses among PFTs. Continuous trait variation was found to be ubiquitous. Responses to moisture availability were generally similar within and between PFTs, but biophysical traits (LA, SLA and LDMC of forbs and grasses responded differently from woody plants. SLA and LDMC responses to temperature were dominated by the prevalence of evergreen PFTs with thick, dense leaves at the warm end of the gradient. Nutrient (N, P and K responses to climate gradients were generally similar within all PFTs. Area-based nutrients generally declined with moisture; Narea and Karea declined with

  10. Quantitative trait locus analysis of leaf morphological characters, yield-related traits, and secondary metabolite contents in Eucommia ulmoides.

    Science.gov (United States)

    Li, Y; Wei, J K; Li, Z Q; Lei, A N; Liu, M H

    2015-12-22

    Eucommia ulmoides is cultivated for the production of eucommia rubber and Chinese herbal drugs. Molecular breeding methods, such as marker-assisted selection (MAS), have the potential to improve the efficiency of E. ulmoides breeding. Quantitative trait locus (QTL) analysis was applied to identify marker-trait associations for E. ulmoides using an F1 mapping population of 152 individuals derived from a cross between the wild genotype Xiaoye and the cultivar Qinzhong No. 1. A total of 78 QTLs were identified for 12 leaf traits involving morphology, yield, and secondary metabolites. Phenotypic variance explained by individual QTLs ranged from 10.4 to 53.3%. Fifteen QTL clusters, each harboring loci controlling at least two leaf traits, were detected across nine linkage groups. Co-location of these QTLs may be due to pleiotropy or linkage. Three main QTL regions for secondary metabolites were consistently identified each year. QTL information from this study furthers our understanding of the genetic architecture of these economically important traits and of MAS in E. ulmoides breeding.

  11. [Spectrum Variance Analysis of Tree Leaves Under the Condition of Different Leaf water Content].

    Science.gov (United States)

    Wu, Jian; Chen, Tai-sheng; Pan, Li-xin

    2015-07-01

    Leaf water content is an important factor affecting tree spectral characteristics. So Exploring the leaf spectral characteristics change rule of the same tree under the condition of different leaf water content and the spectral differences of different tree leaves under the condition of the same leaf water content are not only the keys of hyperspectral vegetation remote sensing information identification but also the theoretical support of research on vegetation spectrum change as the differences in leaf water content. The spectrometer was used to observe six species of tree leaves, and the reflectivity and first order differential spectrum of different leaf water content were obtained. Then, the spectral characteristics of each tree species leaves under the condition of different leaf water content were analyzed, and the spectral differences of different tree species leaves under the condition of the same leaf water content were compared to explore possible bands of the leaf water content identification by hyperspectral remote sensing. Results show that the spectra of each tree leaf have changed a lot with the change of the leaf water content, but the change laws are different. Leaf spectral of different tree species has lager differences in some wavelength range under the condition of same leaf water content, and it provides some possibility for high precision identification of tree species.

  12. Patterns in leaf morphological traits of Chinese woody plants and the application for paleoclimate reconstruction

    Science.gov (United States)

    Li, Yaoqi; Wang, Zhiheng

    2017-04-01

    Leaf morphological traits (LMTs) directly influence carbon-uptake and water-loss of plants in different habitats, and hence can be sensitive indicators of plant interaction with climate. The relationships between community-aggregated LMTs and their surrounding climate have been used to reconstruct paleoclimate. However, the uncertainties in its application remain poorly explored. Using distribution maps and LMTs data (leaf margin states, leaf length, leaf width, and length-width product/ratio) of 10480 Chinese woody dicots and dated family-level phylogenies, we demonstrated the variations of LMTs in geographical patterns, and analyzed their relationships with climate across different life-forms (evergreen and deciduous; trees, shrubs and lianas) and species quartiles with different family-ages. Results showed that from southern to northern China, leaves became shorter and narrower, while leaf length-width ratio increased and toothed-margin percentage decreased. Our results revealed great uncertainties in leaf margin-temperature relationships induced by life-form, precipitation and evolutionary history, and suggested that the widely-used method, leaf margin analysis, should be applied cautiously on paleotemperature reconstruction. Differently, mean leaf size responded tightly to spatial variations in annual evapotranspiration (AET) and primary productivity (GPP and NPP), and these relationships remained constant across different life-forms and evolutionary history, suggesting that leaf size could be a useful surrogate for paleo primary productivity.

  13. Effects of grazing on leaf traits and ecosystem functioning in Inner Mongolia grasslands: scaling from species to community

    Directory of Open Access Journals (Sweden)

    S. X. Zheng

    2010-03-01

    Full Text Available Understanding the mechanistic links between environmental drivers, human disturbance, plant functional traits, and ecosystem properties is a fundamental aspect of biodiversity-ecosystem functioning research. Recent studies have focused mostly on leaf-level traits or community-level weighted traits to predict species responses to grazing and the consequent change in ecosystem functioning. However, studies of leaf-level traits or community-level weighted traits seldom identify the mechanisms linking grazing impact on leaf traits to ecosystem functioning. Here, using a multi-organization-level approach, we examined the effects of grazing on leaf traits (i.e., leaf area, leaf dry mass and specific leaf area and ecosystem functioning across six communities of three vegetation types along a soil moisture gradient in the Xilin River Basin of Inner Mongolia grassland, China. Our results showed that the effects of grazing on leaf traits differed substantially when scaling up from leaf-level to species, functional group (i.e., life forms and water ecotype types, and community levels; and they also varied with vegetation type or site conditions. The effects of grazing on leaf traits diminished progressively along the hierarchy of organizational levels in the meadow, whereas the impacts were predominantly negative and the magnitude of the effects increased considerably at higher organizational levels in the typical steppe. Soil water and nutrient availability, functional trade-offs between leaf size and number of leaves per individual, and differentiation in avoidance and tolerance strategies among coexisting species are likely to be responsible for the observed responses of leaf traits to grazing at different levels of organization and among vegetation types. Our findings also demonstrate that, at both the functional group and community levels, standing aboveground biomass increased with leaf area and specific leaf area. Compared with the large changes in

  14. Leaf economics traits predict litter decomposition of tropical plants and differ among land use types

    NARCIS (Netherlands)

    Bakker, M.A.; Carreño Rocabado, G.; Poorter, L.

    2011-01-01

    1. Decomposition is a key ecosystem process that determines nutrient and carbon cycling. Individual leaf and litter characteristics are good predictors of decomposition rates within biomes worldwide, but knowledge of which traits are the best predictors for tropical species remains scarce. Also, the

  15. Insights into the differences in leaf functional traits of heterophyllous Syringa oblata under different light intensities

    Institute of Scientific and Technical Information of China (English)

    Hongguang Xiao; Congyan Wang; Jun Liu; Lei Wang; Daolin Du

    2015-01-01

    Many plants exhibit heterophylly; the spatially and temporally remarkable ontogenetic differences in leaf morphology may play an adaptative role in their success under diverse habitats. Thus, this study aimed to gain insights into differences in leaf functional traits of heterophyllous Syringa oblata Lindl., which has been widely used as an ornamental tree around the world under different light intensities in East China. No significant differences existed in specific leaf area (SLA) between lanceolate-and heart-shaped leaves. Differ-ences in the investment per unit of light capture surface area deployed between lanceolate-and heart-shaped leaves may be not obvious. This may be attributing to the fact that single leaf wet and dry weight of heart-shaped leaves were significantly higher than those of lanceolate leaves but leaf length and leaf thickness of heart-shaped leaves were significantly lower than those of lanceolate leaves. The SLA of shade trees was sig-nificantly higher than that of sun trees. The investment per unit of light capture surface of shade trees was lower than that of sun trees, making it possible to increase light capture and use efficiency in low-light environments. The phenotypic plas-ticity of most leaf functional traits of lanceolate leaves was higher than those of heart-shaped leaves because the former is the juvenile and the latter is the adult leaf shape during the process of phylogenetic development of S. oblate. The higher range of phenotypic plasticity of leaf thickness and leaf moisture for sun trees may be beneficial to obtain a more efficient control of water loss and nutrient deprivation in high-light environments, and the lower range of phenotypic plas-ticity of single leaf wet and dry weight, and SLA for shade trees may gain an advantage to increase resource (especially light) capture and use efficiency in low-light environments. In brief, the successfully ecological strategy of plants is to find an optimal mode for the trade

  16. Analysis of quantitative trait loci underlying the traits related to chlorophyll content of the flag leaf in rice

    Institute of Scientific and Technical Information of China (English)

    Guohua YANG; Sansi TU; Shaoqing LI; Lingling FENG; Jin KONG; Hui LI; Yangsheng LI

    2008-01-01

    A population of 117 doubled haploid (DH) lines derived from the cross of Zhaiyeqing 8 (indica) x Jingxi 17 (japonica) was employed to map quantitative trait loci (QTL) underlying four physiological traits related to chlorophyll contents of the flag leaf. There were significantly positive correlations among chlorophyll a, chlorophyll b and chlorophyll a+ b content. Chlorophyll a/b ratio was significantly negatively correlated with chlorophyll b content. These four traits were normally distributed with transgressive segregation, suggesting that they were controlled by multiple minor genes. A total of 11 QTLs were detected for the four traits and they lay on six chromosomes. Each of them explained 9.2%-19.6% of the phenotypic variations, respectively. Of these, two QTLs controlling chlorophyll a content were mapped on chromosomes 2 and 5; four QTLs underlying chlorophyll b content were mapped on chromosomes 2, 3, 5 and 9; three QTLs underlying chlorophyll a+b amount were mapped on chromosomes 3, 5 and 9; two QTLs under-lying chlorophyll a/b ratio were mapped on chromosomes 6 and 1 1. The intrinsic relationship among the four traits and the practical implication in rice breeding are discussed.

  17. Intraspecific leaf trait variability along a boreal-to-tropical community diversity gradient

    Science.gov (United States)

    Bastias, Cristina C.; Fortunel, Claire; Valladares, Fernando; Baraloto, Christopher; Benavides, Raquel; Cornwell, William; Markesteijn, Lars; de Oliveira, Alexandre A.; Sansevero, Jeronimo B. B.; Vaz, Marcel C.; Kraft, Nathan J. B.

    2017-01-01

    Disentangling the mechanisms that shape community assembly across diversity gradients is a central matter in ecology. While many studies have explored community assembly through species average trait values, there is a growing understanding that intraspecific trait variation (ITV) can also play a critical role in species coexistence. Classic biodiversity theory hypothesizes that higher diversity at species-rich sites can arise from narrower niches relative to species-poor sites, which would be reflected in reduced ITV as species richness increases. To explore how ITV in woody plant communities changes with species richness, we compiled leaf trait data (leaf size and specific leaf area) in a total of 521 woody plant species from 21 forest communities that differed dramatically in species richness, ranging from boreal to tropical rainforests. At each forest, we assessed ITV as an estimate of species niche breadth and we quantified the degree of trait overlap among co-occurring species as a measure of species functional similarity. We found ITV was relatively invariant across the species richness gradient. In addition, we found that species functional similarity increased with diversity. Contrary to the expectation from classic biodiversity theory, our results rather suggest that neutral processes or equalizing mechanisms can be acting as potential drivers shaping community assembly in hyperdiverse forests. PMID:28241033

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

    Science.gov (United States)

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

    2017-01-01

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

  19. Leaf structural traits of tropical woody species resistant to cement dust.

    Science.gov (United States)

    Siqueira-Silva, Advanio Inácio; Pereira, Eduardo Gusmão; Modolo, Luzia Valentina; Paiva, Elder Antonio Sousa

    2016-08-01

    Cement industries located nearby limestone outcrops in Brazil have contributed to the coating of cement dust over native plant species. However, little is known about the extent of the response of tropical woody plants to such environmental pollutant particularly during the first stages of plant development and establishment. This work focused on the investigation of possible alterations in leaf structural and ultrastructural traits of 5-month-old Guazuma ulmifolia Lam. (Malvaceae), 6-month-old Myracrodruon urundeuva Allemão (Anacardiaceae), and 9-month-old Trichilia hirta L. (Meliaceae) challenged superficially with cement dust during new leaf development. Leaf surface of plants, the soil or both (leaf plus soil), were treated (or not) for 60 days, under controlled conditions, with cement dust at 2.5 or 5.0 mg cm(-2). After exposure, no significant structural changes were observed in plant leaves. Also, no plant death was recorded by the end of the experiment. There was also some evidence of localized leaf necrosis in G. ulmifolia and T. hirta, leaf curling in M. urundeuva and T. hirta, and bulges formation on epidermal surface of T. hirta, after cement dust contact with plant shoots. All species studied exhibited stomata obliteration while T. hirta, in particular, presented early leaf abscission, changes in cellular relief, and organization and content of midrib cells. No significant ultrastructural alterations were detected under the experimental conditions studied. Indeed, mesophyll cells presented plastids with intact membrane systems. The high plant survival rates, together with mild morphoanatomic traits alterations in leaves, indicate that G. ulmifolia is more resistant to cement dust pollutant, followed by M. urundeuva and T. hirta. Thus, the three plant species are promising for being used to revegetate areas impacted by cement industries activities.

  20. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Science.gov (United States)

    Lundholm, Jeremy; Heim, Amy; Tran, Stephanie; Smith, Tyler

    2014-01-01

    Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies) for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that favor less

  1. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that

  2. Stem hydraulic traits and leaf water-stress tolerance are co-ordinated with the leaf phenology of angiosperm trees in an Asian tropical dry karst forest.

    Science.gov (United States)

    Fu, Pei-Li; Jiang, Yan-Juan; Wang, Ai-Ying; Brodribb, Tim J; Zhang, Jiao-Lin; Zhu, Shi-Dan; Cao, Kun-Fang

    2012-07-01

    The co-occurring of evergreen and deciduous angiosperm trees in Asian tropical dry forests on karst substrates suggests the existence of different water-use strategies among species. In this study it is hypothesized that the co-occurring evergreen and deciduous trees differ in stem hydraulic traits and leaf water relationships, and there will be correlated evolution in drought tolerance between leaves and stems. A comparison was made of stem hydraulic conductivity, vulnerability curves, wood anatomy, leaf life span, leaf pressure-volume characteristics and photosynthetic capacity of six evergreen and six deciduous tree species co-occurring in a tropical dry karst forest in south-west China. The correlated evolution of leaf and stem traits was examined using both traditional and phylogenetic independent contrasts correlations. It was found that the deciduous trees had higher stem hydraulic efficiency, greater hydraulically weighted vessel diameter (D(h)) and higher mass-based photosynthetic rate (A(m)); while the evergreen species had greater xylem-cavitation resistance, lower leaf turgor-loss point water potential (π(0)) and higher bulk modulus of elasticity. There were evolutionary correlations between leaf life span and stem hydraulic efficiency, A(m), and dry season π(0). Xylem-cavitation resistance was evolutionarily correlated with stem hydraulic efficiency, D(h), as well as dry season π(0). Both wood density and leaf density were closely correlated with leaf water-stress tolerance and A(m). The results reveal the clear distinctions in stem hydraulic traits and leaf water-stress tolerance between the co-occurring evergreen and deciduous angiosperm trees in an Asian dry karst forest. A novel pattern was demonstrated linking leaf longevity with stem hydraulic efficiency and leaf water-stress tolerance. The results show the correlated evolution in drought tolerance between stems and leaves.

  3. Leaf pH as a plant trait: species-driven rather than soil-driven variation

    National Research Council Canada - National Science Library

    Johannes H. C. Cornelissen; Florus Sibma; Richard S. P. Van Logtestijn; Rob A. Broekman; Ken Thompson

    2011-01-01

    .... But how robust is leaf pH as a species trait in the face of environmental variation? We hypothesized that inherent interspecific variation in leaf pH should be greater than phenotypic variation of given species in response to soil environments. 2...

  4. Effects of phylogeny, leaf traits, and the altitudinal distribution of host plants on herbivore assemblages on congeneric Acer species.

    Science.gov (United States)

    Nakadai, Ryosuke; Murakami, Masashi; Hirao, Toshihide

    2014-08-01

    Historical, niche-based, and stochastic processes have been proposed as the mechanisms that drive community assembly. In plant-herbivore systems, these processes can correspond to phylogeny, leaf traits, and the distribution of host plants, respectively. Although patterns of herbivore assemblages among plant species have been repeatedly examined, the effects of these factors among co-occurring congeneric host plant species have rarely been studied. Our aim was to reveal the process of community assembly for herbivores by investigating the effects of phylogeny, leaf traits, and the altitudinal distribution of closely related host plants of the genus Acer. We sampled leaf functional traits for 30 Acer species in Japan. Using a newly constructed phylogeny, we determined that three of the six measured leaf traits (leaf thickness, C/N ratio, and condensed tannin content) showed a phylogenetic signal. In a field study, we sampled herbivore communities on 14 Acer species within an elevation gradient and examined relationships between herbivore assemblages and host plants. We found that herbivore assemblages were significantly correlated with phylogeny, leaf traits, phylogenetic signals, and the altitudinal distribution of host plants. Our results indicate that the interaction between historical and current ecological processes shapes herbivore community assemblages.

  5. Key innovation or adaptive change? A test of leaf traits using Triodiinae in Australia.

    Science.gov (United States)

    Toon, A; Crisp, M D; Gamage, H; Mant, J; Morris, D C; Schmidt, S; Cook, L G

    2015-07-28

    The evolution of novel traits ("key innovations") allows some lineages to move into new environments or adapt to changing climates, whereas other lineages may track suitable habitat or go extinct. We test whether, and how, trait shifts are linked to environmental change using Triodiinae, C4 grasses that form the dominant understory over about 30% of Australia. Using phylogenetic and relaxed molecular clock estimates, we assess the Australian biogeographic origins of Triodiinae and reconstruct the evolution of stomatal and vascular bundle positioning. Triodiinae diversified from the mid-Miocene, coincident with the aridification of Australia. Subsequent niche shifts have been mostly from the Eremaean biome to the savannah, coincident with the expansion of the latter. Biome shifts are correlated with changes in leaf anatomy and radiations within Triodiinae are largely regional. Symplectrodia and Monodia are nested within Triodia. Rather than enabling biome shifts, convergent changes in leaf anatomy have probably occurred after taxa moved into the savannah biome-they are likely to have been subsequent adaptions rather than key innovations. Our study highlights the importance of testing the timing and origin of traits assumed to be phenotypic innovations that enabled ecological shifts.

  6. Effects of grazing on leaf traits and ecosystem functioning in Inner Mongolia grasslands: scaling from species to community

    Directory of Open Access Journals (Sweden)

    S. X. Zheng

    2009-10-01

    Full Text Available More attention has focused on using some easily measured plant functional traits to predict grazing influence on plant growth and ecosystem functioning. However, there has been much controversy on leaf traits response to grazing, thus more research should be conducted at the species level. Here we investigated the leaf area, leaf mass and specific leaf area (SLA of 263 species in eight grassland communities along a soil moisture gradient in the Xilin River Basin, a semiarid grassland of northern China, to explore the grazing effects on ecosystem functioning. Results demonstrated that grazing decreased the leaf area and leaf mass in more than 56% of species in the Xilin River Basin, however, responses of SLA to grazing varied widely between species. Grazing increased SLA in 38.4% of species, decreased SLA in 31.3% of species and had no effect on 30.3% of species. Annuals and biennials generally developed high SLA as grazing tolerance traits, while perennial graminoids developed low SLA as grazing avoidance traits. Considering the water ecotypes, the SLA-increased and SLA-unchanged species were dominated by hygrophytes and mesophytes, while the SLA-decreased species were dominated by xerophytes. At the community level, grazing decreased the mean leaf area index (LAI of six communities by 16.9%, leaf biomass by 35.2% and standing aboveground biomass (SAB by 35.0% in the Xilin River Basin, indicating that overgrazing greatly decreased the ecosystem functioning in the semi-arid grassland of northern China. Soil properties, especially fielding holding capacity and soil organic carbon and total nitrogen could mediate the negative grazing impacts. The results suggest SLA is a better leaf trait to reveal plant adaptability to grazing. Our findings have practical implications for range management and productivity maintenance in the semiarid grassland, and it is feasible to take some measures such as ameliorating soil water and nutrient availabilities to

  7. Leaf economic traits from fossils support a weedy habit for early angiosperms.

    Science.gov (United States)

    Royer, Dana L; Miller, Ian M; Peppe, Daniel J; Hickey, Leo J

    2010-03-01

    Many key aspects of early angiosperms are poorly known, including their ecophysiology and associated habitats. Evidence for fast-growing, weedy angiosperms comes from the Early Cretaceous Potomac Group, where angiosperm fossils, some of them putative herbs, are found in riparian depositional settings. However, inferences of growth rate from sedimentology and growth habit are somewhat indirect; also, the geographic extent of a weedy habit in early angiosperms is poorly constrained. Using a power law between petiole width and leaf mass, we estimated the leaf mass per area (LMA) of species from three Albian (110-105 Ma) fossil floras from North America (Winthrop Formation, Patapsco Formation of the Potomac Group, and the Aspen Shale). All LMAs for angiosperm species are low (240 g/m(2); mean = 291 g/m(2)). On the basis of extant relationships between LMA and other leaf economic traits such as photosynthetic rate and leaf lifespan, we conclude that these Early Cretaceous landscapes were populated with weedy angiosperms with short-lived leaves (success.

  8. Population-Level Differentiation in Growth Rates and Leaf Traits in Seedlings of the Neotropical Live Oak Quercus oleoides Grown under Natural and Manipulated Precipitation Regimes

    Directory of Open Access Journals (Sweden)

    Jose A. Ramírez-Valiente

    2017-05-01

    Full Text Available Widely distributed species are normally subjected to spatial heterogeneity in environmental conditions. In sessile organisms like plants, adaptive evolution and phenotypic plasticity of key functional traits are the main mechanisms through which species can respond to environmental heterogeneity and climate change. While extended research has been carried out in temperate species in this regard, there is still limited knowledge as to how species from seasonally-dry tropical climates respond to spatial and temporal variation in environmental conditions. In fact, studies of intraspecific genetically-based differences in functional traits are still largely unknown and studies in these ecosystems have largely focused on in situ comparisons where environmental and genetic effects cannot be differentiated. In this study, we tested for ecotypic differentiation and phenotypic plasticity in leaf economics spectrum (LES traits, water use efficiency and growth rates under natural and manipulated precipitation regimes in a common garden experiment where seedlings of eight populations of the neotropical live oak Quercus oleoides were established. We also examined the extent to which intraspecific trait variation was associated with plant performance under different water availability. Similar to interspecific patterns among seasonally-dry tropical tree species, live oak populations with long and severe dry seasons had higher leaf nitrogen content and growth rates than mesic populations, which is consistent with a “fast” resource-acquisition strategy aimed to maximize carbon uptake during the wet season. Specific leaf area (SLA was the best predictor of plant performance, but contrary to expectations, it was negatively associated with relative and absolute growth rates. This observation was partially explained by the negative association between SLA and area-based photosynthetic rates, which is contrary to LES expectations but similar to other recent

  9. Population-Level Differentiation in Growth Rates and Leaf Traits in Seedlings of the Neotropical Live Oak Quercus oleoides Grown under Natural and Manipulated Precipitation Regimes.

    Science.gov (United States)

    Ramírez-Valiente, Jose A; Center, Alyson; Sparks, Jed P; Sparks, Kimberlee L; Etterson, Julie R; Longwell, Timothy; Pilz, George; Cavender-Bares, Jeannine

    2017-01-01

    Widely distributed species are normally subjected to spatial heterogeneity in environmental conditions. In sessile organisms like plants, adaptive evolution and phenotypic plasticity of key functional traits are the main mechanisms through which species can respond to environmental heterogeneity and climate change. While extended research has been carried out in temperate species in this regard, there is still limited knowledge as to how species from seasonally-dry tropical climates respond to spatial and temporal variation in environmental conditions. In fact, studies of intraspecific genetically-based differences in functional traits are still largely unknown and studies in these ecosystems have largely focused on in situ comparisons where environmental and genetic effects cannot be differentiated. In this study, we tested for ecotypic differentiation and phenotypic plasticity in leaf economics spectrum (LES) traits, water use efficiency and growth rates under natural and manipulated precipitation regimes in a common garden experiment where seedlings of eight populations of the neotropical live oak Quercus oleoides were established. We also examined the extent to which intraspecific trait variation was associated with plant performance under different water availability. Similar to interspecific patterns among seasonally-dry tropical tree species, live oak populations with long and severe dry seasons had higher leaf nitrogen content and growth rates than mesic populations, which is consistent with a "fast" resource-acquisition strategy aimed to maximize carbon uptake during the wet season. Specific leaf area (SLA) was the best predictor of plant performance, but contrary to expectations, it was negatively associated with relative and absolute growth rates. This observation was partially explained by the negative association between SLA and area-based photosynthetic rates, which is contrary to LES expectations but similar to other recent intraspecific studies on

  10. Building relationships between plant traits and leaf spectra to reduce uncertainty in terrestrial ecosystem models

    Science.gov (United States)

    Lieberman-Cribbin, W.; Rogers, A.; Serbin, S.; Ely, K.

    2015-12-01

    Despite climate projections, there is uncertainty in how terrestrial ecosystems will respond to warming temperatures and increased atmospheric carbon dioxide concentrations. Earth system models are used to determine how ecosystems will respond in the future, but there is considerable variation in how plant traits are represented within these models. A potential approach to reducing uncertainty is the establishment of spectra-trait linkages among plant species. These relationships allow the accurate estimation of biochemical characteristics of plants from their shortwave spectral profiles. Remote sensing approaches can then be implemented to acquire spectral data and estimate plant traits over large spatial and temporal scales. This paper describes a greenhouse experiment conducted at Brookhaven National Laboratory in which spectra-trait relationships were investigated for 8 different plant species. This research was designed to generate a broad gradient in plant traits, using a range of species grown in different sized pots with different soil type. Fertilizer was also applied in different amounts to generate variation in plant C and N status that will be reflected in the traits measured, as well as the spectra observed. Leaves were sampled at different developmental stages to increase variation. Spectra and plant traits were then measured and a partial least-squares regression (PLSR) modeling approach was used to establish spectra-trait relationships. Despite the variability in growing conditions and plant species, our PLSR models could be used to accurately estimate plant traits from spectral signatures, yielding model calibration R2 and root mean square error (RMSE) values, respectively, of 0.85 and 0.30 for percent nitrogen by mass (Nmass%), R2 0.78 and 0.75 for carbon to nitrogen (C:N) ratio, 0.87 and 2.39 for leaf mass area (LMA), and 0.76 R2 and 15.16 for water (H2O) content. This research forms the basis for establishing new and more comprehensive spectra-trait

  11. Population variation and natural selection on leaf traits in cork oak throughout its distribution range

    Science.gov (United States)

    Ramírez-Valiente, José Alberto; Valladares, Fernando; Sánchez-Gómez, David; Delgado, Antonio; Aranda, Ismael

    2014-07-01

    A central issue in evolutionary biology is the exploration of functional trait variation among populations and the extent to which this variation has adaptive value. It was recently proposed that specific leaf area (SLA), leaf nitrogen concentration per mass (Nmass) and water use efficiency in cork oak play an important role in adaptation to water availability in the environment. In order to investigate this hypothesis, we explored, first, whether there was population-level variation in cork oak (Quercus suber) for these functional traits throughout its distribution range; if this were the case, it would be consistent with the hypothesis that different rainfall patterns have led to ecotypic differentiation in this species. Second, we studied whether the population-level variation matched short-term selection on these traits under different water availability conditions using two fitness components: survival and growth. We found high population-level differentiation in SLA and Nmass, with populations from dry places exhibiting the lowest values for SLA and Nmass. Likewise, reduced SLA had fitness benefits in terms of growth for plants under dry conditions. However, contrary to our expectations, we did not find any pattern of association between functional traits and survival in nine-year-old saplings despite considerable drought during one year of the study period. These results together with findings from the literature suggest that early stages of development are the most critical period for this species. Most importantly, these findings suggest that cork oak saplings have a considerable potential to cope with dry conditions. This capacity to withstand aridity has important implications for conservation of cork oak woodlands under the ongoing climate change.

  12. Differential effects of lichens versus liverworts epiphylls on host leaf traits in the tropical montane rainforest, Hainan Island, China.

    Science.gov (United States)

    Zhou, Lingyan; Liu, Fude; Yang, Wenjie; Liu, Hong; Shao, Hongbo; Wang, Zhongsheng; An, Shuqing

    2014-01-01

    Epiphylls widely colonize vascular leaves in moist tropical forests. Understanding the effects of epiphylls on leaf traits of host plants is critical for understanding ecological function of epiphylls. A study was conducted in a rain forest to investigate leaf traits of the host plants Photinia prunifolia colonized with epiphyllous liverworts and foliicolous lichens as well as those of uncolonized leaves. Our results found that the colonization of lichens significantly decreased leaf water content (LWC), chlorophyll (Chl) a and a + b content, and Chl a/b of P. prunifolia but increased Chl b content, while that of liverworts did not affect them as a whole. The variations of net photosynthetic rates (P n ) among host leaves colonized with different coverage of lichens before or after removal treatment (a treatment to remove epiphylls from leaf surface) were greater than that colonized with liverworts. The full cover of lichens induced an increase of light compensation point (LCP) by 21% and a decrease of light saturation point (LSP) by 54% for their host leaves, whereas that of liverworts displayed contrary effects. Compared with the colonization of liverworts, lichens exhibited more negative effects on the leaf traits of P. prunifolia in different stages of colonization. The results suggest that the responses of host leaf traits to epiphylls are affected by the epiphyllous groups and coverage, which are also crucial factors in assessing ecofunctions of epiphylls in tropical forests.

  13. Differential Effects of Lichens versus Liverworts Epiphylls on Host Leaf Traits in the Tropical Montane Rainforest, Hainan Island, China

    Directory of Open Access Journals (Sweden)

    Lingyan Zhou

    2014-01-01

    Full Text Available Epiphylls widely colonize vascular leaves in moist tropical forests. Understanding the effects of epiphylls on leaf traits of host plants is critical for understanding ecological function of epiphylls. A study was conducted in a rain forest to investigate leaf traits of the host plants Photinia prunifolia colonized with epiphyllous liverworts and foliicolous lichens as well as those of uncolonized leaves. Our results found that the colonization of lichens significantly decreased leaf water content (LWC, chlorophyll (Chl a and a + b content, and Chl a/b of P. prunifolia but increased Chl b content, while that of liverworts did not affect them as a whole. The variations of net photosynthetic rates (Pn among host leaves colonized with different coverage of lichens before or after removal treatment (a treatment to remove epiphylls from leaf surface were greater than that colonized with liverworts. The full cover of lichens induced an increase of light compensation point (LCP by 21% and a decrease of light saturation point (LSP by 54% for their host leaves, whereas that of liverworts displayed contrary effects. Compared with the colonization of liverworts, lichens exhibited more negative effects on the leaf traits of P. prunifolia in different stages of colonization. The results suggest that the responses of host leaf traits to epiphylls are affected by the epiphyllous groups and coverage, which are also crucial factors in assessing ecofunctions of epiphylls in tropical forests.

  14. Leaf morphology of 40 evergreen and deciduous broadleaved subtropical tree species and relationships to functional ecophysiological traits.

    Science.gov (United States)

    Kröber, W; Heklau, H; Bruelheide, H

    2015-03-01

    We explored potential of morphological and anatomical leaf traits for predicting ecophysiological key functions in subtropical trees. We asked whether the ecophysiological parameters stomatal conductance and xylem cavitation vulnerability could be predicted from microscopy leaf traits. We investigated 21 deciduous and 19 evergreen subtropical tree species, using individuals of the same age and from the same environment in the Biodiversity-Ecosystem Functioning experiment at Jiangxi (BEF-China). Information-theoretic linear model selection was used to identify the best combination of morphological and anatomical predictors for ecophysiological functions. Leaf anatomy and morphology strongly depended on leaf habit. Evergreen species tended to have thicker leaves, thicker spongy and palisade mesophyll, more palisade mesophyll layers and a thicker subepidermis. Over 50% of all evergreen species had leaves with multi-layered palisade parenchyma, while only one deciduous species (Koelreuteria bipinnata) had this. Interactions with leaf habit were also included in best multi-predictor models for stomatal conductance (gs ) and xylem cavitation vulnerability. In addition, maximum gs was positively related to log ratio of palisade to spongy mesophyll thickness. Vapour pressure deficit (vpd) for maximum gs increased with the log ratio of palisade to spongy mesophyll thickness in species having leaves with papillae. In contrast, maximum specific hydraulic conductivity and xylem pressure at which 50% loss of maximum specific xylem hydraulic conductivity occurred (Ψ50 ) were best predicted by leaf habit and density of spongy parenchyma. Evergreen species had lower Ψ50 values and lower maximum xylem hydraulic conductivities. As hydraulic leaf and wood characteristics were reflected in structural leaf traits, there is high potential for identifying further linkages between morphological and anatomical leaf traits and ecophysiological responses.

  15. Leaf traits and their interrelationship of 23 plant species in southeast of Keerqin Sandy Lands,China

    Institute of Scientific and Technical Information of China (English)

    Jinhuan LIU; Dehui ZENG; Don Koo LEE; Zhiping FAN; Lei ZHONG

    2008-01-01

    Six leaf traits,i.e.,fresh mass (FM),dry mass (DM),leaf dry matter content (DMC),area (AR),specific leaf area (SLA) and thickness (TH) from 23 plant species in the southeastern Keerqin Sandy Lands,China were measured.The results show that leaf traits of herbs were more diversified than those of shrubs and trees and aver-age SLA tended towards a decreasing trend from herbs to shrubs to trees.On the contrary,DMC and DM show an upward trend from herbs to shrubs to trees.No apparent difference was found in TH.Except for DM and TH,there were significant variations in SLA and DMC among three different growth forms.Moreover,a significant correla-tion was found between SLA and DMC.It is concluded that SLA and DMC could be used to predict species posi-tion along a resource use gradient.

  16. Phenotypic selection on leaf functional traits of two congeneric species in a temperate rainforest is consistent with their shade tolerance.

    Science.gov (United States)

    Gianoli, Ernesto; Saldaña, Alfredo

    2013-09-01

    Several studies across species have linked leaf functional traits with shade tolerance. Because evolution by natural selection occurs within populations, in order to explain those interspecific patterns it is crucial to examine variation of traits associated with shade tolerance and plant fitness at an intraspecific scale. In a southern temperate rainforest, two climbing plant species coexist but differ in shade tolerance. Whereas Luzuriaga radicans is most abundant in the shaded understory, L. polyphylla typically occurs in intermediate light environments. We carried out an intraspecific approach to test the hypothesis of differential selection patterns in relation to shade tolerance in these congeneric species. The probability of showing reproductive structures increased with specific leaf area (SLA) in L. polyphylla, and decreased with dark respiration in L. radicans. When reproductive output of fertile individuals was the fitness variable, we detected positive directional selection on SLA in L. polyphylla, and negative directional selection on dark respiration and positive directional selection on leaf size in L. radicans. Total light radiation differed between the microsites where the Luzuriaga species were sampled in the old-growth forest understory. Accordingly, L. radicans had a lower minimum light requirement and showed fertile individuals in darker microsites. L. radicans showed lower dark respiration, higher chlorophyll content, and greater leaf size and SLA than L. polyphylla. Results suggest that in more shade-tolerant species, established in the darker microsites, selection would favor functional traits minimizing carbon losses, while in less shade-tolerant species, plants displaying leaf traits enhancing light capture would be selected.

  17. Construction of a genetic linkage map and QTL analysis for some leaf traits in pear (Pyrus L .)

    Institute of Scientific and Technical Information of China (English)

    Wenying SUN; Yuxing ZHANG; Wenquan LE; Hai'e ZHANG

    2009-01-01

    The major incompatibility barriers to specific inbred lines and the long generation duration in Pyrus L. May hinder the Pyrus breeding process. A genetic linkage map provides the foundation for quantitative trait loci (QTL) mapping and molecular marker-assisted breeding. In this study, we constructed a genetic map with 145 F1 populations from a cross of two cultivars, Yali and Jingbaili, using AFLP and SSR markers. The map consisted of 18 linkage groups which included 402 genetic markers and covered 1395.9 cM, with an average genetic distance of 3.8 cM. The interval mapping was used to identify quantitative trait loci associated with four leaf agronomic traits in the F1 population. The results indicated that four QTLs were associated with leaf length, two QTLs with leaf width, two with leaf length/leaf width, and three with petiole length. The eleven QTLs were associated with 9.9%-48.5% of the phenotypic variation in different traits. It is considered that the map covers almost the whole genome, and molecular markers will be greatly helpful to the related breeding.

  18. A tale of two plasticities: leaf hydraulic conductances and related traits diverge for two tropical epiphytes from contrasting light environments.

    Science.gov (United States)

    North, Gretchen B; Browne, Marvin G; Fukui, Kyle; Maharaj, Franklin D R; Phillips, Carly A; Woodside, Walter T

    2016-07-01

    We compared the effects of different light environments on leaf hydraulic conductance (Kleaf ) for two congeneric epiphytes, the tank bromeliads Guzmania lingulata (L.) Mez and Guzmania monostachia (L.) Rusby ex Mez. They occur sympatrically at the study site, although G. monostachia is both wider ranging and typically found in higher light. We collected plants from two levels of irradiance and measured Kleaf as well as related morphological and anatomical traits. Leaf xylem conductance (Kxy ) was estimated from tracheid dimensions, and leaf conductance outside the xylem (Kox ) was derived from a leaky cable model. For G. monostachia, but not for G. lingulata, Kleaf and Kxy were significantly higher in high light conditions. Under both light conditions, Kxy and Kox were co-limiting for the two species, and all conductances were in the low range for angiosperms. With respect to hydraulic conductances and a number of related anatomical traits, G. monostachia exhibited greater plasticity than did G. lingulata, which responded to high light chiefly by reducing leaf size. The positive plasticity of leaf hydraulic traits in varying light environments in G. monostachia contrasted with negative plasticity in leaf size for G. lingulata, suggesting that G. monostachia may be better able to respond to forest conditions that are likely to be warmer and more disturbed in the future.

  19. Species-Specific Effects on Throughfall Kinetic Energy in Subtropical Forest Plantations Are Related to Leaf Traits and Tree Architecture.

    Science.gov (United States)

    Goebes, Philipp; Bruelheide, Helge; Härdtle, Werner; Kröber, Wenzel; Kühn, Peter; Li, Ying; Seitz, Steffen; von Oheimb, Goddert; Scholten, Thomas

    2015-01-01

    Soil erosion is a key threat to many ecosystems, especially in subtropical China where high erosion rates occur. While the mechanisms that induce soil erosion on agricultural land are well understood, soil erosion processes in forests have rarely been studied. Throughfall kinetic energy (TKE) is influenced in manifold ways and often determined by the tree's leaf and architectural traits. We investigated the role of species identity in mono-specific stands on TKE by asking to what extent TKE is species-specific and which leaf and architectural traits account for variation in TKE. We measured TKE of 11 different tree species planted in monocultures in a biodiversity-ecosystem-functioning experiment in subtropical China, using sand-filled splash cups during five natural rainfall events in summer 2013. In addition, 14 leaf and tree architectural traits were measured and linked to TKE. Our results showed that TKE was highly species-specific. Highest TKE was found below Choerospondias axillaris and Sapindus saponaria, while Schima superba showed lowest TKE. These species-specific effects were mediated by leaf habit, leaf area (LA), leaf pinnation, leaf margin, stem diameter at ground level (GD), crown base height (CBH), tree height, number of branches and leaf area index (LAI) as biotic factors and throughfall as abiotic factor. Among these, leaf habit, tree height and LA showed the highest effect sizes on TKE and can be considered as major drivers of TKE. TKE was positively influenced by LA, GD, CBH, tree height, LAI, and throughfall amount while it was negatively influenced by the number of branches. TKE was lower in evergreen, simple leaved and dentate leaved than in deciduous, pinnated or entire leaved species. Our results clearly showed that soil erosion in forest plantations can be mitigated by the appropriate choice of tree species.

  20. Species-Specific Effects on Throughfall Kinetic Energy in Subtropical Forest Plantations Are Related to Leaf Traits and Tree Architecture.

    Directory of Open Access Journals (Sweden)

    Philipp Goebes

    Full Text Available Soil erosion is a key threat to many ecosystems, especially in subtropical China where high erosion rates occur. While the mechanisms that induce soil erosion on agricultural land are well understood, soil erosion processes in forests have rarely been studied. Throughfall kinetic energy (TKE is influenced in manifold ways and often determined by the tree's leaf and architectural traits. We investigated the role of species identity in mono-specific stands on TKE by asking to what extent TKE is species-specific and which leaf and architectural traits account for variation in TKE. We measured TKE of 11 different tree species planted in monocultures in a biodiversity-ecosystem-functioning experiment in subtropical China, using sand-filled splash cups during five natural rainfall events in summer 2013. In addition, 14 leaf and tree architectural traits were measured and linked to TKE. Our results showed that TKE was highly species-specific. Highest TKE was found below Choerospondias axillaris and Sapindus saponaria, while Schima superba showed lowest TKE. These species-specific effects were mediated by leaf habit, leaf area (LA, leaf pinnation, leaf margin, stem diameter at ground level (GD, crown base height (CBH, tree height, number of branches and leaf area index (LAI as biotic factors and throughfall as abiotic factor. Among these, leaf habit, tree height and LA showed the highest effect sizes on TKE and can be considered as major drivers of TKE. TKE was positively influenced by LA, GD, CBH, tree height, LAI, and throughfall amount while it was negatively influenced by the number of branches. TKE was lower in evergreen, simple leaved and dentate leaved than in deciduous, pinnated or entire leaved species. Our results clearly showed that soil erosion in forest plantations can be mitigated by the appropriate choice of tree species.

  1. On the challenges of using field spectroscopy to measure the impact of soil type on leaf traits

    Science.gov (United States)

    Nunes, Matheus H.; Davey, Matthew P.; Coomes, David A.

    2017-07-01

    Understanding the causes of variation in functional plant traits is a central issue in ecology, particularly in the context of global change. Spectroscopy is increasingly used for rapid and non-destructive estimation of foliar traits, but few studies have evaluated its accuracy when assessing phenotypic variation in multiple traits. Working with 24 chemical and physical leaf traits of six European tree species growing on strongly contrasting soil types (i.e. deep alluvium versus nearby shallow chalk), we asked (i) whether variability in leaf traits is greater between tree species or soil type, and (ii) whether field spectroscopy is effective at predicting intraspecific variation in leaf traits as well as interspecific differences. Analysis of variance showed that interspecific differences in traits were generally much stronger than intraspecific differences related to soil type, accounting for 25 % versus 5 % of total trait variation, respectively. Structural traits, phenolic defences and pigments were barely affected by soil type. In contrast, foliar concentrations of rock-derived nutrients did vary: P and K concentrations were lower on chalk than alluvial soils, while Ca, Mg, B, Mn and Zn concentrations were all higher, consistent with the findings of previous ecological studies. Foliar traits were predicted from 400 to 2500 nm reflectance spectra collected by field spectroscopy using partial least square regression, a method that is commonly employed in chemometrics. Pigments were best modelled using reflectance data from the visible region (400-700 nm), while all other traits were best modelled using reflectance data from the shortwave infrared region (1100-2500 nm). Spectroscopy delivered accurate predictions of species-level variation in traits. However, it was ineffective at detecting intraspecific variation in rock-derived nutrients (with the notable exception of P). The explanation for this failure is that rock-derived elements do not have absorption

  2. Invasive species' leaf traits and dissimilarity from natives shape their impact on nitrogen cycling: a meta-analysis.

    Science.gov (United States)

    Lee, Marissa R; Bernhardt, Emily S; van Bodegom, Peter M; Cornelissen, J Hans C; Kattge, Jens; Laughlin, Daniel C; Niinemets, Ülo; Peñuelas, Josep; Reich, Peter B; Yguel, Benjamin; Wright, Justin P

    2017-01-01

    Many exotic species have little apparent impact on ecosystem processes, whereas others have dramatic consequences for human and ecosystem health. There is growing evidence that invasions foster eutrophication. We need to identify species that are harmful and systems that are vulnerable to anticipate these consequences. Species' traits may provide the necessary insights. We conducted a global meta-analysis to determine whether plant leaf and litter functional traits, and particularly leaf and litter nitrogen (N) content and carbon: nitrogen (C : N) ratio, explain variation in invasive species' impacts on soil N cycling. Dissimilarity in leaf and litter traits among invaded and noninvaded plant communities control the magnitude and direction of invasion impacts on N cycling. Invasions that caused the greatest increases in soil inorganic N and mineralization rates had a much greater litter N content and lower litter C : N in the invaded than the reference community. Trait dissimilarities were better predictors than the trait values of invasive species alone. Quantifying baseline community tissue traits, in addition to those of the invasive species, is critical to understanding the impacts of invasion on soil N cycling. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  3. Leaf habit does not determine the investment in both physical and chemical defences and pair-wise correlations between these defensive traits.

    Science.gov (United States)

    Moreira, X; Pearse, I S

    2017-05-01

    Plant life-history strategies associated with resource acquisition and economics (e.g. leaf habit) are thought to be fundamental determinants of the traits and mechanisms that drive herbivore pressure, resource allocation to plant defensive traits, and the simultaneous expression (positive correlations) or trade-offs (negative correlations) between these defensive traits. In particular, it is expected that evergreen species - which usually grow slower and support constant herbivore pressure in comparison with deciduous species - will exhibit higher levels of both physical and chemical defences and a higher predisposition to the simultaneous expression of physical and chemical defensive traits. Here, by using a dataset which included 56 oak species (Quercus genus), we investigated whether leaf habit of plant species governs the investment in both physical and chemical defences and pair-wise correlations between these defensive traits. Our results showed that leaf habit does not determine the production of most leaf physical and chemical defences. Although evergreen oak species had higher levels of leaf toughness and specific leaf mass (physical defences) than deciduous oak species, both traits are essentially prerequisites for evergreenness. Similarly, our results also showed that leaf habit does not determine pair-wise correlations between defensive traits because most physical and chemical defensive traits were simultaneously expressed in both evergreen and deciduous oak species. Our findings indicate that leaf habit does not substantially contribute to oak species differences in plant defence investment. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Autism spectrum traits in children with anxiety disorders

    NARCIS (Netherlands)

    van Steensel, F.J.A.; Bögels, S.M.; Wood, J.J.

    2013-01-01

    The aim of this study was to examine ASD traits in children with clinical anxiety in early development, as well as current manifestations. Parents of 42 children with an anxiety disorder (but no known diagnosis of ASD) and 42 typically developing children were interviewed using the Autism Diagnostic

  5. Autism Spectrum Traits in Children with Anxiety Disorders

    Science.gov (United States)

    van Steensel, Francisca J. A.; Bogels, Susan M.; Wood, Jeffrey J.

    2013-01-01

    The aim of this study was to examine ASD traits in children with clinical anxiety in early development, as well as current manifestations. Parents of 42 children with an anxiety disorder (but no known diagnosis of ASD) and 42 typically developing children were interviewed using the Autism Diagnostic Interview (ADI-R). They also completed…

  6. [Effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of western Sichuan, China].

    Science.gov (United States)

    Xu, Zhen-feng; Hu, Ting-xing; Zhang, Li; Zhang, Yuan-bin; Xian, Jun-ren; Wang, Kai-yun

    2009-01-01

    By using open-top chamber (OTC), the effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of Western Sichuan were studied. The results showed that comparing with the control, the mean air temperature at 1.2 m above the ground throughout S. eriostachya growth season in OTC increased by 2.9 degrees C, while the soil temperature at the depth of 5 cm only increased by 0.4 degrees C. The temperature increase in OTC made S. eriostachya budding advanced and defoliation postponed obviously, and the leaf life-span longer. The leaf and branch growth rates as well as the specific leaf area in OTC increased obviously, whereas the leaf nitrogen concentration decreased significantly. In OTC, the stomata conductance, net photosynthetic rate, photorespiration, and dark respiration rate of S. eriostachya all exhibited an increasing trend. It was suggested that S. eriostachya had stronger capability to adapt to warming, and, under the background of future global climate change, the elevation of S. eriostachya distribution in the timberline ecotone would be likely to ascend.

  7. Leaf mechanical resistance in plant trait databases: comparing the results of two common measurement methods.

    Science.gov (United States)

    Enrico, Lucas; Díaz, Sandra; Westoby, Mark; Rice, Barbara L

    2016-01-01

    The influence of leaf mechanical properties on local ecosystem processes, such as trophic transfer, decomposition and nutrient cycling, has resulted in a growing interest in including leaf mechanical resistance in large-scale databases of plant functional traits. 'Specific work to shear' and 'force to tear' are two properties commonly used to describe mechanical resistance (toughness or strength) of leaves. Two methodologies have been widely used to measure them across large datasets. This study aimed to assess correlations and standardization between the two methods, as measured by two widely used apparatuses, in order to inter-convert existing data in those global datasets. Specific work to shear (W(SS)) and force to tear (FT) were measured in leaves of 72 species from south-eastern Australia. The measurements were made including and excluding midribs. Relationships between the variables were tested by Spearman correlations and ordinary least square regressions. A positive and significant correlation was found between the methods, but coefficients varied according to the inclusion or exclusion of the midrib in the measurements. Equations for prediction varied according to leaf venation pattern. A positive and significant (r = 0·90, P resistance data obtained with both methodologies could be pooled together into a single coarser variable, using the equations provided in this paper. However, more detailed datasets of FT cannot be safely filled in with estimations based on W(SS), or vice versa. In addition, W(SS) values of green leaves can be predicted with good accuracy from W(SS) of rehydrated leaves of the same species. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Leaf anatomical traits which accommodate the facultative engagement of crassulacean acid metabolism in tropical trees of the genus Clusia.

    Science.gov (United States)

    Barrera Zambrano, V Andrea; Lawson, Tracy; Olmos, Enrique; Fernández-García, Nieves; Borland, Anne M

    2014-07-01

    Succulence and leaf thickness are important anatomical traits in CAM plants, resulting from the presence of large vacuoles to store organic acids accumulated overnight. A higher degree of succulence can result in a reduction in intercellular air space which constrains internal conductance to CO2. Thus, succulence presents a trade-off between the optimal anatomy for CAM and the internal structure ideal for direct C3 photosynthesis. This study examined how plasticity for the reversible engagement of CAM in the genus Clusia could be accommodated by leaf anatomical traits that could facilitate high nocturnal PEPC activity without compromising the direct day-time uptake of CO2 via Rubisco. Nine species of Clusia ranging from constitutive C3 through C3/CAM intermediates to constitutive CAM were compared in terms of leaf gas exchange, succulence, specific leaf area, and a range of leaf anatomical traits (% intercellular air space (IAS), length of mesophyll surface exposed to IAS per unit area, cell size, stomatal density/size). Relative abundances of PEPC and Rubisco proteins in different leaf tissues of a C3 and a CAM-performing species of Clusia were determined using immunogold labelling. The results indicate that the relatively well-aerated spongy mesophyll of Clusia helps to optimize direct C3-mediated CO2 fixation, whilst enlarged palisade cells accommodate the potential for C4 carboxylation and nocturnal storage of organic acids. The findings provide insight on the optimal leaf anatomy that could accommodate the bioengineering of inducible CAM into C3 crops as a means of improving water use efficiency without incurring detrimental consequences for direct C3-mediated photosynthesis.

  9. Phylogenetic spectrum and analysis of antibacterial activities of leaf extracts from plants of the genus Rhododendron.

    Science.gov (United States)

    Rezk, Ahmed; Nolzen, Jennifer; Schepker, Hartwig; Albach, Dirk C; Brix, Klaudia; Ullrich, Matthias S

    2015-03-18

    Plants are traditionally used for medicinal treatment of numerous human disorders including infectious diseases caused by microorganisms. Due to the increasing resistance of many pathogens to commonly used antimicrobial agents, there is an urgent need for novel antimicrobial compounds. Plants of the genus Rhododendron belong to the woody representatives of the family Ericaceae, which are typically used in a range of ethno-medical applications. There are more than one thousand Rhododendron species worldwide. The Rhododendron-Park Bremen grows plants representing approximately 600 of the known Rhododendron species, and thus enables research involving almost two thirds of all known Rhododendron species. Twenty-six bacterial species representing different taxonomic clades have been used to study the antimicrobial potential of Rhododendron leaf extracts. Agar diffusion assay were conducted using 80% methanol crude extracts derived from 120 Rhododendron species. Data were analyzed using principal component analysis and the plant-borne antibacterial activities grouped according the first and second principal components. The leaf extracts of 17 Rhododendron species exhibited significant growth-inhibiting activities against Gram-positive bacteria. In contrast, only very few of the leaf extracts affected the growth of Gram-negative bacteria. All leaf extracts with antimicrobial bioactivity were extracted from representatives of the subgenus Rhododendron, with 15 from the sub-section Rhododendron and two belonging to the section Pogonanthum. The use of bacterial multidrug efflux pump mutants revealed remarkable differences in the susceptibility towards Rhododendron leaf extract treatment. For the first time, our comprehensive study demonstrated that compounds with antimicrobial activities accumulate in the leaves of certain Rhododendron species, which mainly belong to a particular subgenus. The results suggested that common genetic traits are responsible for the production of

  10. Retrieval of forest leaf functional traits from HySpex imagery using radiative transfer models and continuous wavelet analysis

    Science.gov (United States)

    Ali, Abebe Mohammed; Skidmore, Andrew K.; Darvishzadeh, Roshanak; van Duren, Iris; Holzwarth, Stefanie; Mueller, Joerg

    2016-12-01

    Quantification of vegetation properties plays an important role in the assessment of ecosystem functions with leaf dry mater content (LDMC) and specific leaf area (SLA) being two key functional traits. For the first time, these two leaf traits have been estimated from the airborne images (HySpex) using the INFORM radiative transfer model and Continuous Wavelet Analysis (CWA). Ground truth data, were collected for 33 sample plots during a field campaign in July 2013 in the Bavarian Forest National Park, Germany, concurrent with the hyperspectral overflight. The INFORM model was used to simulate the canopy reflectance of the test site and the simulated spectra were transformed to wavelet features by applying CWA. Next, the top 1% strongly correlated wavelet features with the LDMC and SLA were used to develop predictive (regression) models. The two leaf traits were then retrieved using the CWA transformed HySpex imagery and the predictive models. The results were validated using R2 and the RMSE of the estimated and measured variables. Our results revealed strong correlations between six wavelet features and LDMC, as well as between four wavelet features and SLA. The wavelet features at 1741 nm (scale 5) and 2281 nm (scale 4) were the two most strongly correlated with LDMC and SLA respectively. The combination of all the identified wavelet features for LDMC yielded the most accurate prediction (R2 = 0.59 and RMSE = 4.39%). However, for SLA the most accurate prediction was obtained from the single most correlated feature: 2281 nm, scale 4 (R2 = 0.85 and RMSE = 4.90). Our results demonstrate the applicability of Continuous Wavelet Analysis (CWA) when inverting radiative transfer models, for accurate mapping of forest leaf functional traits.

  11. Overlap of autistic and schizotypal traits in adolescents with Autism Spectrum Disorders.

    Science.gov (United States)

    Barneveld, Petra S; Pieterse, Jolijn; de Sonneville, Leo; van Rijn, Sophie; Lahuis, Bertine; van Engeland, Herman; Swaab, Hanna

    2011-03-01

    This study addresses the unraveling of the relationship between autism spectrum and schizophrenia spectrum traits in a population of adolescents with Autism Spectrum Disorders (ASD). Recent studies comparing isolated symptoms of both spectrum disorders as well as diagnostic criteria for each (DSM-IV-TR) suggest resemblances in the clinical phenotype. A group of 27 adolescents with ASD (11 to 18 years) and 30 typically developing adolescents, matched for age and gender, participated in this study. Within the ASD group 11 adolescents satisfied DSM-IV-TR criteria for schizotypal personality disorders. Autistic and schizotypal traits were identified by means of well validated questionnaires (Autism Questionnaire, AQ and Schizotypal Personality Questionnaire-Revised, SPQ). Significantly more schizotypal traits in adolescents with ASD were found than in typically developing controls. Besides high levels of negative symptoms, adolescents with ASD also displayed high levels of positive and disorganized symptoms. There appeared to be a relationship between the mean level of autistic symptoms and schizotypal traits, as well as specific associations between autistic symptoms and negative, disorganized and positive schizotypal symptoms within individuals. Schizotypal symptomatology in all sub dimensions that are reflected by the SPQ scores, was most prominently associated with attention switching problems of the autism symptoms from the AQ. These findings indicate that patients diagnosed with an ASD show schizophrenia spectrum traits in adolescence. Although other studies have provided empirical support for this overlap in diagnostic criteria between both spectrum disorders, the present findings add to the literature that behavioral overlap is not limited to negative schizotypal symptoms, but extends to disorganized and positive symptoms as well.

  12. Investigation of Autism Spectrum Disorder and Autistic Traits in an Adolescent Sample with Anorexia Nervosa

    Science.gov (United States)

    Postorino, Valentina; Scahill, Lawrence; De Peppo, Lavinia; Fatta, Laura Maria; Zanna, Valeria; Castiglioni, Maria Chiara; Gillespie, Scott; Vicari, Stefano; Mazzone, Luigi

    2017-01-01

    This study aimed to examine the presence of Autism Spectrum Disorder (ASD) in a sample of female adolescents with Anorexia Nervosa (AN) during the acute phase of illness. We also compare the level of autistic traits, social perception skills and obsessive-compulsive symptoms in four groups: AN, ASD, and two gender- and age-matched control groups.…

  13. Examining Autistic Traits in Children with ADHD: Does the Autism Spectrum Extend to ADHD?

    Science.gov (United States)

    Grzadzinski, Rebecca; Di Martino, Adriana; Brady, Emily; Mairena, Maria Angeles; O'Neale, Matthew; Petkova, Eva; Lord, Catherine; Castellanos, F. Xavier

    2011-01-01

    We examined to what extent increased parent reports of autistic traits in some children with Attention Deficit Hyperactivity Disorder (ADHD) are the result of ADHD-related symptoms or qualitatively similar to the core characteristics of autism spectrum disorders (ASD). Results confirm the presence of a subgroup of children with ADHD and elevated…

  14. Maladaptive personality traits increase subjectively during the course of schizophrenia spectrum disorders.

    Science.gov (United States)

    Schroeder, Katrin; Naber, Dieter; Huber, Christian G

    2014-04-01

    We assessed both current maladaptive personality traits (MPTs) and, retrospectively, premorbid MPTs in patients with schizophrenia spectrum disorders (SSDs). This was to examine whether the patients had the impression that their personality had changed and which traits were affected. We also wanted to determine whether the perceived changes could be explained by SSD psychopathology. MPTs were assessed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnoses, axis II disorders, screening questionnaire and interview, integrating questions on subjective estimation of premorbid MPTs in moderately ill SSD patients. Forty-five patients were included. Premorbid MPTs were remembered as significantly less pronounced than current MPTs for the whole spectrum of personality traits (p < 0.001). Antisocial traits had worsened significantly less (p < 0.001), and borderline and obsessive-compulsive traits had worsened significantly more (both p < 0.01) than the mean increase. Associations between MPT increase and SSD psychopathology were significant for schizotypal, avoidant, and depressive traits. According to the patients' retrospective assessment, MPTs increased through onset and course of SSDs. Memory bias, depressed mood, and SSD symptoms alone could not sufficiently explain these differences. Subjective MPT increase may play a role for the patients' concept of illness, quality of life, and adherence to therapeutic interventions. It should be addressed in SSD treatment.

  15. Reduced Accuracy and Sensitivity in the Perception of Emotional Facial Expressions in Individuals with High Autism Spectrum Traits

    Science.gov (United States)

    Poljac, Ervin; Poljac, Edita; Wagemans, Johan

    2013-01-01

    Autism spectrum disorder (ASD) is among other things characterized by specific impairments in emotion processing. It is not clear, however, to what extent the typical decline in affective functioning is related to the specific autistic traits. We employed "The Autism Spectrum-Quotient" (AQ) to quantify autistic traits in a group of 500…

  16. Characterization and Genetic Analysis of a Novel Rice Spotted-leaf Mutant HM47 with Broad-spectrum Resistance to Xanthomonas oryzae pv.oryzae(F)

    Institute of Scientific and Technical Information of China (English)

    Bao-Hua Feng; Yang Yang; Yong-Feng Shi; Hai-Chao Shen; Hui-Mei Wang; Qi-Na Huang; Xia Xu

    2013-01-01

    A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified.The mutant expressed hypersensitive response (HR)-like symptoms throughout its whole life from the first leaf to the flag leaf,without pathogen invasion.Initiation of the lesions was induced by light under natural summer field conditions.Expression of pathogenesis-related genes including PAL,PO-C1,POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type (WT).Disease reaction to Xanthomonas oryzae pv.oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested.An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions.Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene,tentatively named splHM47,flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4.Ten open reading frames are predicted,and all of them are expressed proteins.Isolation and validation of the putative genes are currently underway.

  17. Theory of mind impairment: a distinct trait-marker for schizophrenia spectrum disorders and bipolar disorder?

    Science.gov (United States)

    Bora, E; Yücel, M; Pantelis, C

    2009-10-01

    The aim of this study was to critically review the literature in order to determine if Theory of Mind (ToM) impairment can be considered a trait-marker for schizophrenia spectrum disorders and bipolar disorder (BD). After a thorough literature search, we reviewed the empirical studies investigating ToM impairments in remitted schizophrenia patients, first episode patients, subjects at high-risk (HR) for psychosis and first-degree relatives of schizophrenia patients. Studies investigating ToM impairment in other schizophrenia spectrum conditions, affective psychosis and BD were also reviewed. ToM abnormalities exist at onset and continue throughout the course of schizophrenia, persist into remission, and while less severe, are apparent in HR populations. Mentalizing impairments are also observed in other forms of psychotic illness and BD. Mentalizing impairment in schizophrenia spectrum disorders and BD might reflect underlying general cognitive deficits and residual symptom expression, rather than representing a specific trait-marker.

  18. Inheritance of the Pale-Green Leaf Marker and Sterility Trait in Photo-Thermo Sensitive Genic Male Sterile Rice

    Institute of Scientific and Technical Information of China (English)

    TIAN Zhen-tao; XUE Qing-zhong

    2003-01-01

    P/TGMS (photo-thermo sensitive genic male sterility) lines with pale-green leaf color have beendeveloped in japonica rice. The marker trait is used as an assistant selection in the production of the two-linessystem hybrid rice for the improvement of F1 seed purity. A joint inheritance study of both leaf color and malesterility is presented for P/TGMS line with pale-green leaf color. The segregation ratios for leaf color in the F2populations of the three crosses showed 13 : 3 and 15 : 1 at early and late sowing stages (April 26 and June23) respectively, implying that the leaf color is controlled by two genes with fertility gene as dominant. Steril-ity level is higher in the early sowing stage than that in the late sowing. The inducement of male sterility isclosely related to longer day-length and higher temperature at the developmental stages of young panicle. Thegenes to govern the leaf color and male fertility are inherited independently.

  19. Comparison of Leaf Sheath Transcriptome Profiles with Physiological Traits of Bread Wheat Cultivars under Salinity Stress.

    Science.gov (United States)

    Takahashi, Fuminori; Tilbrook, Joanne; Trittermann, Christine; Berger, Bettina; Roy, Stuart J; Seki, Motoaki; Shinozaki, Kazuo; Tester, Mark

    2015-01-01

    Salinity stress has significant negative effects on plant biomass production and crop yield. Salinity tolerance is controlled by complex systems of gene expression and ion transport. The relationship between specific features of mild salinity stress adaptation and gene expression was analyzed using four commercial varieties of bread wheat (Triticum aestivum) that have different levels of salinity tolerance. The high-throughput phenotyping system in The Plant Accelerator at the Australian Plant Phenomics Facility revealed variation in shoot relative growth rate and salinity tolerance among the four cultivars. Comparative analysis of gene expression in the leaf sheaths identified genes whose functions are potentially linked to shoot biomass development and salinity tolerance. Early responses to mild salinity stress through changes in gene expression have an influence on the acquisition of stress tolerance and improvement in biomass accumulation during the early "osmotic" phase of salinity stress. In addition, results revealed transcript profiles for the wheat cultivars that were different from those of usual stress-inducible genes, but were related to those of plant growth. These findings suggest that, in the process of breeding, selection of specific traits with various salinity stress-inducible genes in commercial bread wheat has led to adaptation to mild salinity conditions.

  20. Comparison of Leaf Sheath Transcriptome Profiles with Physiological Traits of Bread Wheat Cultivars under Salinity Stress.

    Directory of Open Access Journals (Sweden)

    Fuminori Takahashi

    Full Text Available Salinity stress has significant negative effects on plant biomass production and crop yield. Salinity tolerance is controlled by complex systems of gene expression and ion transport. The relationship between specific features of mild salinity stress adaptation and gene expression was analyzed using four commercial varieties of bread wheat (Triticum aestivum that have different levels of salinity tolerance. The high-throughput phenotyping system in The Plant Accelerator at the Australian Plant Phenomics Facility revealed variation in shoot relative growth rate and salinity tolerance among the four cultivars. Comparative analysis of gene expression in the leaf sheaths identified genes whose functions are potentially linked to shoot biomass development and salinity tolerance. Early responses to mild salinity stress through changes in gene expression have an influence on the acquisition of stress tolerance and improvement in biomass accumulation during the early "osmotic" phase of salinity stress. In addition, results revealed transcript profiles for the wheat cultivars that were different from those of usual stress-inducible genes, but were related to those of plant growth. These findings suggest that, in the process of breeding, selection of specific traits with various salinity stress-inducible genes in commercial bread wheat has led to adaptation to mild salinity conditions.

  1. Comparison of Leaf Sheath Transcriptome Profiles with Physiological Traits of Bread Wheat Cultivars under Salinity Stress

    KAUST Repository

    Takahashi, Fuminori

    2015-08-05

    Salinity stress has significant negative effects on plant biomass production and crop yield. Salinity tolerance is controlled by complex systems of gene expression and ion transport. The relationship between specific features of mild salinity stress adaptation and gene expression was analyzed using four commercial varieties of bread wheat (Triticum aestivum) that have different levels of salinity tolerance. The high-throughput phenotyping system in The Plant Accelerator at the Australian Plant Phenomics Facility revealed variation in shoot relative growth rate and salinity tolerance among the four cultivars. Comparative analysis of gene expression in the leaf sheaths identified genes whose functions are potentially linked to shoot biomass development and salinity tolerance. Early responses to mild salinity stress through changes in gene expression have an influence on the acquisition of stress tolerance and improvement in biomass accumulation during the early “osmotic” phase of salinity stress. In addition, results revealed transcript profiles for the wheat cultivars that were different from those of usual stress-inducible genes, but were related to those of plant growth. These findings suggest that, in the process of breeding, selection of specific traits with various salinity stress-inducible genes in commercial bread wheat has led to adaptation to mild salinity conditions.

  2. Biological and Geographical Sources of Variation in Leaf Economic and Hydraulic Traits Throughout the Los Angeles Megacity

    Science.gov (United States)

    Ibsen, P.; Arps, S.; Shiflett, S. A.; Jenerette, D.

    2015-12-01

    Leaf functional traits act as driving forces on each other, as well as being driven by abiotic factors. Leaf Nitrogen Content (LNC), Specific Leaf Area (SLA) and maximum conductance to water vapor (gwmax) are well researched, yet their relationship to each other and the climate is still not fully understood. Urban setting provides a unique look into trait relationships because of the high plant biodiversity, distribution of plants outside their native climate conditions, well-watered conditions that remove a key abiotic factor and soil nutrient availability varies due to atmospheric nitrogen deposition. We predict owing to these conditions, both LNC and gwmax will increase in across the climate gradient of the LA area. Ten tree species were sampled from green spaces across the L.A Megacity in three geographic areas of focus: coastal (Irvine), inland (Riverside) and desert (Palm Springs), exhibiting a gradient of increasing MAT, and nitrogen deposition peaking inland. Leaf samples were processed for N, and gwmax was quantified through stomatal characteristics. LNC increased between the coastal and inland region (mean diff. -0.324; p=0.007). For two case study species, gwmax in the genus' Jacaranda and Pyrus show a contrasting positive and negative correlation with LNC (Jacaranda: p=0.037, Pyrus: ptraits tradeoffs are dependent on the evolutionary characteristics of the species (Drought deciduous sub-tropical Jacaranda's large compound leaves, and average sampled SLA: 94.05; winter deciduous temperate Pyrus' simple leaf with average SLA: 61.78). The increase in N along one section of the gradient, but not the other, potentially shows the driving force of the N deposition may outweigh the forces of MAT. If the variation in driving forces behind economic and hydraulic traits can be identified, there will be a significant increase in the predictive power of how urban vegetation responds to climatic shifts.

  3. Identification and mapping of leaf, stem and stripe rust resistance quantitative trait loci and their interactions in durum wheat.

    Science.gov (United States)

    Singh, A; Pandey, M P; Singh, A K; Knox, R E; Ammar, K; Clarke, J M; Clarke, F R; Singh, R P; Pozniak, C J; Depauw, R M; McCallum, B D; Cuthbert, R D; Randhawa, H S; Fetch, T G

    2013-02-01

    Leaf rust (Puccinia triticina Eriks.), stripe rust (Puccinia striiformis f. tritici Eriks.) and stem rust (Puccinia graminis f. sp. tritici) cause major production losses in durum wheat (Triticum turgidum L. var. durum). The objective of this research was to identify and map leaf, stripe and stem rust resistance loci from the French cultivar Sachem and Canadian cultivar Strongfield. A doubled haploid population from Sachem/Strongfield and parents were phenotyped for seedling reaction to leaf rust races BBG/BN and BBG/BP and adult plant response was determined in three field rust nurseries near El Batan, Obregon and Toluca, Mexico. Stripe rust response was recorded in 2009 and 2011 nurseries near Toluca and near Njoro, Kenya in 2010. Response to stem rust was recorded in field nurseries near Njoro, Kenya, in 2010 and 2011. Sachem was resistant to leaf, stripe and stem rust. A major leaf rust quantitative trait locus (QTL) was identified on chromosome 7B at Xgwm146 in Sachem. In the same region on 7B, a stripe rust QTL was identified in Strongfield. Leaf and stripe rust QTL around DArT marker wPt3451 were identified on chromosome 1B. On chromosome 2B, a significant leaf rust QTL was detected conferred by Strongfield, and at the same QTL, a Yr gene derived from Sachem conferred resistance. Significant stem rust resistance QTL were detected on chromosome 4B. Consistent interactions among loci for resistance to each rust type across nurseries were detected, especially for leaf rust QTL on 7B. Sachem and Strongfield offer useful sources of rust resistance genes for durum rust breeding.

  4. Plant functional types are more efficient than climate in predicting spectrums of trait variation in evergreen angiosperm trees of tropical Australia and China

    Science.gov (United States)

    Togashi, H. F.; Prentice, I. C. C.; Atkin, O. K.; Bloomfield, K. J.; Bradford, M.; Weerasinghe, L. K.; Harrison, S. P.; Evans, B. J.; Liddell, M. J.; Wang, H.; Cao, K. F.; Fan, Z.

    2015-12-01

    The representation of Plant Functional Types (PFTs) in current generation of Dynamic Global Vegetation Models (DGVMs) is excessively simplistically. Key ecophysiological properties, such as photosynthesis biochemistry, are most times merely averaged and trade-off with other plant traits is often neglected. Validation of a PFT framework based in photosynthetic process is crucial to improve reliability of DGVMs. We present 431 leaf-biochemical and wood level measurements in evergreen angiosperm trees of tropical forests in Australia and China that were divided in four spectrums of plant trait variation: metabolic, structural, hydraulic and height dimensions. Plant traits divided in each of these dimensions adopt survival strategies reflected more clearly by trade-off within each spectrum, and in some extent across spectrums. Co-ordination theory (that Rubisco- and electron-transport limited rates of photosynthesis are co-limiting) and least-coast theory (that intercellular to ambient CO2 concentration minimizes the combined costs per unit carbon assimilation, regulating maximum height and wood density) expectations matched PFT (which takes in account canopy position and light access, and life spam) variation. Our findings suggest that climate (air moisture, air temperature, light) has lower power representing these dimensions, in comparison to the PFT framework.

  5. Functional traits drive the contribution of solar radiation to leaf litter decomposition among multiple arid-zone species.

    Science.gov (United States)

    Pan, Xu; Song, Yao-Bin; Liu, Guo-Fang; Hu, Yu-Kun; Ye, Xue-Hua; Cornwell, William K; Prinzing, Andreas; Dong, Ming; Cornelissen, Johannes H C

    2015-08-18

    In arid zones, strong solar radiation has important consequences for ecosystem processes. To better understand carbon and nutrient dynamics, it is important to know the contribution of solar radiation to leaf litter decomposition of different arid-zone species. Here we investigated: (1) whether such contribution varies among plant species at given irradiance regime, (2) whether interspecific variation in such contribution correlates with interspecific variation in the decomposition rate under shade; and (3) whether this correlation can be explained by leaf traits. We conducted a factorial experiment to determine the effects of solar radiation and environmental moisture for the mass loss and the decomposition constant k-values of 13 species litters collected in Northern China. The contribution of solar radiation to leaf litter decomposition varied significantly among species. Solar radiation accelerated decomposition in particular in the species that already decompose quickly under shade. Functional traits, notably specific leaf area, might predict the interspecific variation in that contribution. Our results provide the first empirical evidence for how the effect of solar radiation on decomposition varies among multiple species. Thus, the effect of solar radiation on the carbon flux between biosphere and atmosphere may depend on the species composition of the vegetation.

  6. Impact of Leaf Traits on Temporal Dynamics of Transpired Oxygen Isotope Signatures and Its Impact on Atmospheric Vapor.

    Science.gov (United States)

    Dubbert, Maren; Kübert, Angelika; Werner, Christiane

    2017-01-01

    Oxygen isotope signatures of transpiration (δ E ) are powerful tracers of water movement from plant to global scale. However, a mechanistic understanding of how leaf morphological/physiological traits effect δ E is missing. A laser spectrometer was coupled to a leaf-level gas-exchange system to measure fluxes and isotopic signatures of plant transpiration under controlled conditions in seven distinct species (Fagus sylvatica, Pinus sylvestris, Acacia longifolia, Quercus suber, Coffea arabica, Plantago lanceolata, Oxalis triangularis). We analyzed the role of stomatal conductance (gs ) and leaf water content (W) on the temporal dynamics of δ E following changes in relative humidity (rH). Changes in rH were applied from 60 to 30% and from 30 to 60%, which is probably more than covering the maximum step changes occurring under natural conditions. Further, the impact of gs and W on isotopic non-steady state isofluxes was analyzed. Following changes in rH, temporal development of δ E was well described by a one-pool modeling approach for most species. Isofluxes of δ E were dominantly driven by stomatal control on E, particularly for the initial period of 30 min following a step change. Hence, the deviation of isofluxes from isotopic steady state can be large, even though plants transpire near to isotopic steady state. Notably, not only transpiration rate and stomatal conductance, but also the leaf traits stomatal density (as a measure of gmax) and leaf water content are significantly related to the time constant (τ) and non-steady-state isofluxes. This might provide an easy-to-access means of a priori assumptions for the impact of isotopic non-steady-state transpiration in various ecosystems. We discuss the implications of our results from leaf to ecosystem scale.

  7. Impact of Leaf Traits on Temporal Dynamics of Transpired Oxygen Isotope Signatures and Its Impact on Atmospheric Vapor

    Science.gov (United States)

    Dubbert, Maren; Kübert, Angelika; Werner, Christiane

    2017-01-01

    Oxygen isotope signatures of transpiration (δE) are powerful tracers of water movement from plant to global scale. However, a mechanistic understanding of how leaf morphological/physiological traits effect δE is missing. A laser spectrometer was coupled to a leaf-level gas-exchange system to measure fluxes and isotopic signatures of plant transpiration under controlled conditions in seven distinct species (Fagus sylvatica, Pinus sylvestris, Acacia longifolia, Quercus suber, Coffea arabica, Plantago lanceolata, Oxalis triangularis). We analyzed the role of stomatal conductance (gs) and leaf water content (W) on the temporal dynamics of δE following changes in relative humidity (rH). Changes in rH were applied from 60 to 30% and from 30 to 60%, which is probably more than covering the maximum step changes occurring under natural conditions. Further, the impact of gs and W on isotopic non-steady state isofluxes was analyzed. Following changes in rH, temporal development of δE was well described by a one-pool modeling approach for most species. Isofluxes of δE were dominantly driven by stomatal control on E, particularly for the initial period of 30 min following a step change. Hence, the deviation of isofluxes from isotopic steady state can be large, even though plants transpire near to isotopic steady state. Notably, not only transpiration rate and stomatal conductance, but also the leaf traits stomatal density (as a measure of gmax) and leaf water content are significantly related to the time constant (τ) and non-steady-state isofluxes. This might provide an easy-to-access means of a priori assumptions for the impact of isotopic non-steady-state transpiration in various ecosystems. We discuss the implications of our results from leaf to ecosystem scale. PMID:28149303

  8. Validation and dissection of quantitative trait loci for leaf traits in interval RM4923-RM402 on the short arm of rice chromosome 6

    Indian Academy of Sciences (India)

    Bo Shen; Wei-Dong Yu; Jing-Hong Du; Ye-Yang Fan; Ji-Rong Wu; Jie-Yun Zhuang

    2011-04-01

    Validation and dissection of a QTL region for leaf traits in rice which has been reported in a number of independent studies were conducted. Three sets of near isogenic lines (NILs) were originated from a residual heterozygous line derived the indica cross Zhenshan 97B/Milyang 46. They were overlapping and totally covered a 4.2-Mb heterogenous region extending from RM4923 to RM402 on the short arm of rice chromosome 6. Each NIL set consisted of 10 maternal lines and 10 paternal lines. They were measured for the length, width, perimeter and area of the top three leaves and the number of spikelets per panicle, number of grains per panicle and grain weight per panicle. In NIL sets 6-4 and 6-7, differing in intervals RM4923-RM225 and RM19410-RM6119, respectively, significant variations with the enhancing alleles from the female parent ZS97 were shown for the length, perimeter and area except for the area of the third leaf from top in 6-4, but the effects were lower in 6-4 than in 6-7. No significant effects were detected for the three traits in the remaining NIL set. It was shown that flag leaf length (FLL) is the primary target of the QTLs detected. Two QTLs for FLL linked in repulsion phase were resolved, of which qFLL6.2 located in the 1.19-Mb interval RM3414-RM6917 had a major effect with the enhancing allele from Zhenshan 97B, and qFLL6.1 located in the 946.8-kb interval RM19350-RM19410 had a smaller effect with the enhancing allele from Milyang 46. The two QTLs also exerted pleiotropic effects on the yield traits.

  9. The spectrum of mutations controlling complex traits and the genetics of fitness in plants.

    Science.gov (United States)

    Falke, K Christin; Glander, Shirin; He, Fei; Hu, Jinyong; de Meaux, Juliette; Schmitz, Gregor

    2013-12-01

    Elucidating the molecular basis of natural variation in complex traits is the key for their effective management in crops or natural systems. This review focuses on plant variation. It will first, show that genetic modifications causing major alterations in polygenic phenotypes often hit targets within an array of 'candidate genes', second, present new methods that include mutations of all effect sizes, and help exhaustively describe the molecular systems underlying complex traits, and third, discuss recent findings regarding the role of epigenetic variants, which in plants are often maintained through both mitosis and meiosis. Exploring the whole spectrum of mutations controlling complex traits is made possible by the combination of genetic, genomic and epigenomic approaches.

  10. Dyspraxia and autistic traits in adults with and without autism spectrum conditions

    OpenAIRE

    Cassidy, Sarah; Hannant, Penelope; Tavassoli, Teresa; Allison, Carrie; Smith, Paula; Baron-Cohen, Simon

    2016-01-01

    Background Autism spectrum conditions (ASC) are frequently associated with motor coordination difficulties. However, no studies have explored the prevalence of dyspraxia in a large sample of individuals with and without ASC or associations between dyspraxia and autistic traits in these individuals. Methods Two thousand eight hundred seventy-one adults (with ASC) and 10,706 controls (without ASC) self-reported whether they have been diagnosed with dyspraxia. A subsample of participants then co...

  11. Positive Traits in the Bipolar Spectrum: The Space between Madness and Genius.

    Science.gov (United States)

    Greenwood, Tiffany A

    2017-02-01

    Bipolar disorder is a severe, lifelong mood disorder for which little is currently understood of the genetic mechanisms underlying risk. By examining related dimensional phenotypes, we may further our understanding of the disorder. Creativity has a historical connection with the bipolar spectrum and is particularly enhanced among unaffected first-degree relatives and those with bipolar spectrum traits. This suggests that some aspects of the bipolar spectrum may confer advantages, while more severe expressions of symptoms negatively influence creative accomplishment. Creativity is a complex, multidimensional construct with both cognitive and affective components, many of which appear to reflect a shared genetic vulnerability with bipolar disorder. It is suggested that a subset of bipolar risk variants confer advantages as positive traits according to an inverted-U-shaped curve with clinically unaffected allele carriers benefitting from the positive traits and serving to maintain the risk alleles in the population. The association of risk genes with creativity in healthy individuals (e.g., NRG1), as well as an overall sharing of common genetic variation between bipolar patients and creative individuals, provides support for this model. Current findings are summarized from a multidisciplinary perspective to demonstrate the feasibility of research in this area to reveal the mechanisms underlying illness.

  12. Quantitative trait loci for cell wall components in recombinant inbred lines of maize (Zea mays L.) II: leaf sheath tissue.

    Science.gov (United States)

    Krakowsky, M D; Lee, M; Coors, J G

    2006-02-01

    While maize silage is a significant feed component in animal production operations, little information is available on the genetic bases of fiber and lignin concentrations in maize, which are negatively correlated with digestibility. Fiber is composed largely of cellulose, hemicellulose and lignin, which are the primary components of plant cell walls. Variability for these traits in maize germplasm has been reported, but the sources of the variation and the relationships between these traits in different tissues are not well understood. In this study, 191 recombinant inbred lines of B73 (low-intermediate levels of cell wall components, CWCs) x De811 (high levels of CWCs) were analyzed for quantitative trait loci (QTL) associated with CWCs in the leaf sheath. Samples were harvested from plots at two locations in 1998 and one in 1999 and assayed for neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL). QTL were detected on all ten chromosomes, most in tissue specific clusters in concordance with the high genotypic correlations for CWCs within the same tissue. Adjustment of NDF for its subfraction, ADF, revealed that most of the genetic variation in NDF was probably due to variation in ADF. The low to moderate genotypic correlations for the same CWC across leaf sheath and stalk tissues indicate that some genes for CWCs may only be expressed in certain tissues. Many of the QTL herein were detected in other populations, and some are linked to candidate genes for cell wall carbohydrate biosynthesis.

  13. Callous unemotional traits, autism spectrum disorder symptoms and empathy in boys with oppositional defiant disorder or conduct disorder

    NARCIS (Netherlands)

    Pijper, Jarla; de Wied, Minet; van Rijn, Sophie; van Goozen, Stephanie; Swaab, Hanna; Meeus, W.H.J.

    2016-01-01

    This study examined additive and interactive effects of callous unemotional (CU) traits and autism spectrum disorders (ASD) symptoms in relation to trait empathy, in boys with oppositional defiant disorder (ODD) or conduct disorder (CD). Participants were 49 boys with ODD/CD, aged between 7-12 years

  14. Phenotypic plasticity and local adaptation in leaf ecophysiological traits of 13 contrasting cork oak populations under different water availabilities.

    Science.gov (United States)

    Ramírez-Valiente, Jose Alberto; Sánchez-Gómez, David; Aranda, Ismael; Valladares, Fernando

    2010-05-01

    Plants distributed across a wide range of environmental conditions are submitted to differential selective pressures. Long-term selection can lead to the development of adaptations to the local environment, generating ecotypic differentiation. Additionally, plant species can cope with this environmental variability by phenotypic plasticity. In this study, we examine the importance of both processes in coping with environmental heterogeneity in the Mediterranean sclerophyllous cork oak Quercus suber. For this purpose, we measured growth and key functional traits at the leaf level in 9-year-old plants across 2 years of contrasting precipitation (2005 and 2006) in a common garden. Plants were grown from acorns originated from 13 populations spanning a wide range of climates along the distribution range of the species. The traits measured were: leaf size (LS), specific leaf area (SLA), carbon isotope discrimination (Delta(13)C) and leaf nitrogen content per unit mass (N(mass)). Inter-population differences in LS, SLA and Delta(13)C were found. These differences were associated with rainfall and temperature at the sites of origin, suggesting local adaptation in response to diverging climates. Additionally, SLA and LS exhibited positive responses to the increase in annual rainfall. Year effect explained 28% of the total phenotypic variance in LS and 2.7% in SLA. There was a significant genotype x environment interaction for shoot growth and a phenotypic correlation between the difference in shoot growth among years and the annual mean temperature at origin. This suggests that populations originating from warm sites can benefit more from wet conditions than populations from cool sites. Finally, we investigated the relationships between functional traits and aboveground growth by several regression models. Our results showed that plants with lower SLA presented larger aboveground growth in a dry year and plants with larger leaf sizes displayed larger growth rates in both

  15. Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms.

    Science.gov (United States)

    Paradiso, Roberta; Arena, Carmen; De Micco, Veronica; Giordano, Maria; Aronne, Giovanna; De Pascale, Stefania

    2017-01-01

    The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs). However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L.) Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. 'Pr91m10' in closed nutrient film technique (NFT). Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control) plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm(2)), thicker palisade parenchyma (95.0 vs. 85.8 μm), and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%), compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP) was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO2 m(-2) s(-1) at the beginning of flowering). These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control); conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area) and seed yield (+36.9%) compared to control. Our results confirm that PGPMs may confer benefits in

  16. Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms

    Directory of Open Access Journals (Sweden)

    Roberta Paradiso

    2017-05-01

    Full Text Available The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs. However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L. Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. ‘Pr91m10’ in closed nutrient film technique (NFT. Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm2, thicker palisade parenchyma (95.0 vs. 85.8 μm, and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%, compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO2 m-2 s-1 at the beginning of flowering. These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control; conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area and seed yield (+36.9% compared to control. Our results confirm that PGPMs may confer benefits in

  17. Identification of sequence-related amplified polymorphism markers linked to the red leaf trait in ornamental kale (Brassica oleracea L. var. acephala).

    Science.gov (United States)

    Wang, Y S; Liu, Z Y; Li, Y F; Zhang, Y; Yang, X F; Feng, H

    2013-04-02

    Artistic diversiform leaf color is an important agronomic trait that affects the market value of ornamental kale. In the present study, genetic analysis showed that a single-dominant gene, Re (red leaf), determines the red leaf trait in ornamental kale. An F2 population consisting of 500 individuals from the cross of a red leaf double-haploid line 'D05' with a white leaf double-haploid line 'D10' was analyzed for the red leaf trait. By combining bulked segregant analysis and sequence-related amplified polymorphism technology, we identified 3 markers linked to the Re/re locus. A genetic map of the Re locus was constructed using these sequence-related amplified polymorphism markers. Two of the markers, Me8Em4 and Me8Em17, were located on one side of Re/re at distances of 2.2 and 6.4 cM, whereas the other marker, Me9Em11, was located on the other side of Re/re at a distance of 3.7 cM. These markers could be helpful for the subsequent cloning of the red trait gene and marker-assisted selection in ornamental kale breeding programs.

  18. Ampelometric Leaf Trait and SSR Loci Selection for a Multivariate Statistical Approach in Vitis vinifera L. Biodiversity Management.

    Science.gov (United States)

    Alba, Vittorio; Bergamini, Carlo; Genghi, Rosalinda; Gasparro, Marica; Perniola, Rocco; Antonacci, Donato

    2015-08-01

    High estimated heritability values were recently revealed for mature leaf traits in grape (Vitis vinifera L.), thus redeeming ampelography in the era of molecular markers. The "Organisation Internationale de la Vigne et du Vin (OIV)" set a list of hundreds of descriptors for grapevine in order to standardize ampelographic and ampelometric scores. Therefore, the selection and reduction of the number of OIV codes can represent a major goal for leaner biodiversity assessment studies. The identification of ampelometric traits associated with grape diversity allows to construct Classification Trees with chi squared automatic interaction detection (CHAID) algorithm, a stepwise model-fitting method that produces a tree diagram in which at each step the sample pool is splitted based on the independent variables statistically different for the dependent variable. A collection of 100 table and wine grapevines (Vitis vinifera L.) was characterized and evaluated by means of six microsatellites and twenty-two ampelometric traits on mature leaves. Nine ampelometric traits were selected by principal component analysis and employed to build the classification trees based on CHAID algorithm. The strategy can represent an effective tool for grape biodiversity management, right allocations, and identification of new grape genotypes, implemented by a further microsatellite investigation only when unsolved cases occur, allowing faster and cheaper results.

  19. Investigation of Autism Spectrum Disorder and Autistic Traits in an Adolescent Sample with Anorexia Nervosa.

    Science.gov (United States)

    Postorino, Valentina; Scahill, Lawrence; De Peppo, Lavinia; Fatta, Laura Maria; Zanna, Valeria; Castiglioni, Maria Chiara; Gillespie, Scott; Vicari, Stefano; Mazzone, Luigi

    2017-04-01

    This study aimed to examine the presence of Autism Spectrum Disorder (ASD) in a sample of female adolescents with Anorexia Nervosa (AN) during the acute phase of illness. We also compare the level of autistic traits, social perception skills and obsessive-compulsive symptoms in four groups: AN, ASD, and two gender- and age-matched control groups. Of the 30 AN participants, only three scored above the conventional ADOS-2 threshold for ASD. The AN participants were similar to their controls on autistic trait measures, and to the ASD group on obsessive-compulsive measures, and on theory of mind ability and affect recognition measures. Further longitudinal studies are needed in order to determine the association between these conditions.

  20. Reduced accuracy and sensitivity in the perception of emotional facial expressions in individuals with high autism spectrum traits

    NARCIS (Netherlands)

    Poljac, E.; Wagemans, J.P.

    2013-01-01

    Autism spectrum disorder (ASD) is among other things characterized by specific impairments in emotion processing. It is not clear, however, to what extent the typical decline in affective functioning is related to the specific autistic traits. We employed The Autism Spectrum-Quotient (AQ) to quantif

  1. Using the Autism-Spectrum Quotient to Measure Autistic Traits in Anorexia Nervosa: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Westwood, Heather; Eisler, Ivan; Mandy, William; Leppanen, Jenni; Treasure, Janet; Tchanturia, Kate

    2016-01-01

    Interest in the link between Autism Spectrum Disorder (ASD) and Anorexia Nervosa (AN) has led to estimates of the prevalence of autistic traits in AN. This systematic review and meta-analysis assessed the use of the Autism-Spectrum Quotient (AQ) or abbreviated version (AQ-10) to examine whether patients with AN have elevated levels of autistic…

  2. Scaling, propagating and mapping uncertainty in spectroscopy-derived foliar traits from the leaf to the image

    Science.gov (United States)

    Singh, A.; Serbin, S. P.; Kingdon, C.; Townsend, P. A.

    2013-12-01

    A major goal of remote sensing, and imaging spectroscopy in particular, is the development of generalizable algorithms to repeatedly and accurately map ecosystem properties such as canopy chemistry across space and time. Existing methods must therefore be tested across a range of measurement approaches to identify and overcome limits to the consistent retrieval of such properties from spectroscopic imagery. Here we illustrate a general approach for the estimation of key foliar biochemical and morphological traits from spectroscopic imagery derived from the AVIRIS instrument and the propagation of errors from the leaf to the image scale using partial least squares regression (PLSR) techniques. Our method involves the integration of three types of data representing different scales of observation: At the image scale, the images were normalized for atmospheric, illumination and BRDF effects. Spectra from field plot locations were extracted from the 51AVIRIS images and were averaged when the field plot was larger than a single pixel. At the plot level, the scaling was conducted using multiple replicates (1000) derived from the leaf-level uncertainty estimates to generate plot-level estimates with their associated uncertainties. Leaf-level estimates of foliar traits (%N, %C, %Fiber, %Cellulose, %Lignin, LMA) were scaled to the canopy based on relative species composition of each plot. Image spectra were iteratively split into 50/50 randomized calibration-validation datasets and multiple (500) trait-predictive PLSR models were generated, this time sampling from within the plot-level uncertainty distribution. This allowed the propagation of uncertainty from the leaf-level dependent variables to the plot level, and finally to models built using AVIRIS image spectra. Moreover, this method allows us to generate spatially explicit maps of uncertainty in our sampled traits. Both LMA and %N PLSR models had a R2 greater than 0.8, root mean square errors (RMSEs) for both

  3. Leaf traits show different relationships with shade tolerance in moist versus dry tropical forests

    NARCIS (Netherlands)

    Poorter, L.

    2009-01-01

    ¿ Shade tolerance is the central paradigm for understanding forest succession and dynamics, but there is considerable debate as to what the salient features of shade tolerance are, whether adult leaves show similar shade adaptations to seedling leaves, and whether the same leaf adaptations are found

  4. The relationship between carers' report of autistic traits and clinical diagnoses of autism spectrum disorders in adults with intellectual disability.

    Science.gov (United States)

    Bhaumik, Sabyasachi; Tyrer, Freya; Barrett, Mary; Tin, Nyunt; McGrother, Catherine W; Kiani, Reza

    2010-01-01

    It is often difficult to determine the triad of impairments and whether autistic features are the consequence of intellectual impairment or autism spectrum disorders in people with intellectual disability (ID). The aim of the current study was to investigate the relationship between carer-reported autistic traits and independent diagnoses of autism spectrum disorders (ASD). Data were collected on carers' subjective report of autistic traits and clinical diagnoses of ASD. Of 1145 adults with ID identified, 220 (19%) individuals had a diagnosis of ASD, and 778 (68%) individuals had at least one autistic trait. Optimal sensitivity and specificity were achieved with two or more autistic traits (sensitivity 63%; specificity 79%) and the positive predictive value increased substantially as the number of autistic traits increased. However, a significant proportion of individuals with ID who did not have a diagnosis of ASD also displayed autistic traits. Our findings suggest that in the absence of other measures, the presence of autistic traits can serve as a useful proxy measure for ASD in research (and/or clinical settings). However, although information on autistic traits may help healthcare practitioners to identify people with possible ASD, it cannot be used alone to make a formal diagnosis.

  5. Genetic control and combining ability of flag leaf area and relative water content traits of bread wheat cultivars under drought stress condition

    Directory of Open Access Journals (Sweden)

    Golparvar Ahmad Reza

    2013-01-01

    Full Text Available In order to compare mode of inheritance, combining ability, heterosis and gene action in genetic control of traits flag leaf area, relative water content and grain filling rate of bread wheat under drought stress, a study was conducted on 8 cultivars using of Griffing’s method2 in fixed model. Mean square of general combining ability was significant also for all traits and mean square of specific combining ability was significant also for all traits except relative water content of leaf which show importance of both additive and dominant effects of genes in heredity of these traits under stress. GCA to SCA mean square ratio was significant for none of traits. Results of this study showed that non additive effects of genes were more important than additive effect for all traits. According to results we can understand that genetic improvement of mentioned traits will have low genetic efficiency by selection from the best crosses of early generations. Then it is better to delay selection until advanced generations and increase in heritability of these traits.

  6. Quantitative Variation in Water-Use Efficiency across Water Regimes and Its Relationship with Circadian, Vegetative, Reproductive, and Leaf Gas-Exchange Traits

    Institute of Scientific and Technical Information of China (English)

    Christine E. Edwards; Brent E. Ewers; C. Robertson McClung; Ping Lou; Cynthia Weinig

    2012-01-01

    Drought limits light harvesting,resulting in lower plant growth and reproduction.One trait important for plant drought response is water-use efficiency (WUE).We investigated (1) how the joint genetic architecture of WUE,reproductive characters,and vegetative traits changed across drought and well-watered conditions,(2) whether traits with distinct developmental bases (e.g.leaf gas exchange versus reproduction) differed in the environmental sensitivity of their genetic architecture,and (3) whether quantitative variation in circadian period was related to drought response in Brassica rapa.Overall,WUE increased in drought,primarily because stomatal conductance,and thus water loss,declined more than carbon fixation.Genotypes with the highest WUE in drought expressed the lowest WUE in well-watered conditions,and had the largest vegetative and floral organs in both treatments.Thus,large changes in WUE enabled some genotypes to approach vegetative and reproductive trait optima across environments.The genetic architecture differed for gas-exchange and vegetative traits across drought and well-watered conditions,but not for floral traits.Correlations between circadian and leaf gas-exchange traits were significant but did not vary across treatments,indicating that circadian period affects physiological function regardless of water availability.These results suggest that WUE is important for drought tolerance in Brassica rapa and that artificial selection for increased WUE in drought will not result in maladaptive expression of other traits that are correlated with WUE.

  7. Canopy position affects the relationships between leaf respiration and associated traits in a tropical rainforest in Far North Queensland.

    Science.gov (United States)

    Weerasinghe, Lasantha K; Creek, Danielle; Crous, Kristine Y; Xiang, Shuang; Liddell, Michael J; Turnbull, Matthew H; Atkin, Owen K

    2014-06-01

    We explored the impact of canopy position on leaf respiration (R) and associated traits in tree and shrub species growing in a lowland tropical rainforest in Far North Queensland, Australia. The range of traits quantified included: leaf R in darkness (RD) and in the light (RL; estimated using the Kok method); the temperature (T)-sensitivity of RD; light-saturated photosynthesis (Asat); leaf dry mass per unit area (LMA); and concentrations of leaf nitrogen (N), phosphorus (P), soluble sugars and starch. We found that LMA, and area-based N, P, sugars and starch concentrations were all higher in sun-exposed/upper canopy leaves, compared with their shaded/lower canopy and deep-shade/understory counterparts; similarly, area-based rates of RD, RL and Asat (at 28 °C) were all higher in the upper canopy leaves, indicating higher metabolic capacity in the upper canopy. The extent to which light inhibited R did not differ significantly between upper and lower canopy leaves, with the overall average inhibition being 32% across both canopy levels. Log-log RD-Asat relationships differed between upper and lower canopy leaves, with upper canopy leaves exhibiting higher rates of RD for a given Asat (both on an area and mass basis), as well as higher mass-based rates of RD for a given [N] and [P]. Over the 25-45 °C range, the T-sensitivity of RD was similar in upper and lower canopy leaves, with both canopy positions exhibiting Q10 values near 2.0 (i.e., doubling for every 10 °C rise in T) and Tmax values near 60 °C (i.e., T where RD reached maximal values). Thus, while rates of RD at 28 °C decreased with increasing depth in the canopy, the T-dependence of RD remained constant; these findings have important implications for vegetation-climate models that seek to predict carbon fluxes between tropical lowland rainforests and the atmosphere.

  8. Fast-growing Acer rubrum differs from slow-growing Quercus alba in leaf, xylem and hydraulic trait coordination responses to simulated acid rain.

    Science.gov (United States)

    Medeiros, Juliana S; Tomeo, Nicholas J; Hewins, Charlotte R; Rosenthal, David M

    2016-08-01

    We investigated the effects of historic soil chemistry changes associated with acid rain, i.e., reduced soil pH and a shift from nitrogen (N)- to phosphorus (P)-limitation, on the coordination of leaf water demand and xylem hydraulic supply traits in two co-occurring temperate tree species differing in growth rate. Using a full-factorial design (N × P × pH), we measured leaf nutrient content, water relations, leaf-level and canopy-level gas exchange, total biomass and allocation, as well as stem xylem anatomy and hydraulic function for greenhouse-grown saplings of fast-growing Acer rubrum (L.) and slow-growing Quercus alba (L.). We used principle component analysis to characterize trait coordination. We found that N-limitation, but not P-limitation, had a significant impact on plant water relations and hydraulic coordination of both species. Fast-growing A. rubrum made hydraulic adjustments in response to N-limitation, but trait coordination was variable within treatments and did not fully compensate for changing allocation across N-availability. For slow-growing Q. alba, N-limitation engendered more strict coordination of leaf and xylem traits, resulting in similar leaf water content and hydraulic function across all treatments. Finally, low pH reduced the propensity of both species to adjust leaf water relations and xylem anatomical traits in response to nutrient manipulations. Our data suggest that a shift from N- to P-limitation has had a negative impact on the water relations and hydraulic function of A. rubrum to a greater extent than for Q. alba We suggest that current expansion of A. rubrum populations could be tempered by acidic N-deposition, which may restrict it to more mesic microsites. The disruption of hydraulic acclimation and coordination at low pH is emphasized as an interesting area of future study.

  9. 不同尺度生态学中植物叶性状研究概述%Research Advances of Plant Leaf Traits at Different Ecology Scales

    Institute of Scientific and Technical Information of China (English)

    毛伟; 李玉霖; 张铜会; 赵学勇; 黄迎新; 宋琳琳

    2012-01-01

    植物叶性状与植物个体、群落、生态系统功能的基本行为和功能具有密切相关性,可反映植物适应环境变化所形成的生存对策。目前有关叶性状的研究非常多,从不同尺度(个体尺度、功能群尺度、群落尺度和区域及全球尺度)对叶的性状进行了研究。个体尺度叶性状的研究着重于揭示单个或多个植物种叶性状对不同环境因子(如温度、土壤水分等)的响应;不同功能群之间植物性状的分异表明环境因子对功能群而言存在选择压力(如低氮),但在功能群内部,选择压力较弱;随群落结构的改变,群落叶性状平均值和建群种叶性状均存在显著变化;大尺度(区域和全球)的研究有助于定量化阐述叶性状分异规律及其与气候等环境因子之间的相关性。目前的研究没有从机理上阐述清楚植物叶性状对环境因子的响应、群落构建过程中植物叶性状的指示作用、叶性状分异的生物地理格局等,在未来的研究中应予以更多关注。%Plant leaf traits are associated with fundamental behavior and function of plant individual,community,and ecosystem.It can reflect plant survival strategy response to different environmental factors.We synthesize the research advance on leaf traits at different ecology scale,such as individual scale,functional group scale,community scale and global scale.Individual scale focuses on the leaf traits response to environment factor or muti-factors,such as temperature,soil moisture and soil nutrient.The differences of leaf traits occur among different functional groups,it probably is an outcome of environment selection,and the selective pressure is relatively weak within each group.As the community structure changes,the leaf traits average value of the community and the leaf traits of the dominate species also changes.Studies at large-scale reveal that high level of trait disparity is observed within community

  10. 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

  11. Systems-level Proteomics of Two Ubiquitous Leaf Commensals Reveals Complementary Adaptive Traits for Phyllosphere Colonization.

    Science.gov (United States)

    Müller, Daniel B; Schubert, Olga T; Röst, Hannes; Aebersold, Ruedi; Vorholt, Julia A

    2016-10-01

    Plants are colonized by a diverse community of microorganisms, the plant microbiota, exhibiting a defined and conserved taxonomic structure. Niche separation based on spatial segregation and complementary adaptation strategies likely forms the basis for coexistence of the various microorganisms in the plant environment. To gain insights into organism-specific adaptations on a molecular level, we selected two exemplary community members of the core leaf microbiota and profiled their proteomes upon Arabidopsis phyllosphere colonization. The highly quantitative mass spectrometric technique SWATH MS was used and allowed for the analysis of over two thousand proteins spanning more than three orders of magnitude in abundance for each of the model strains. The data suggest that Sphingomonas melonis utilizes amino acids and hydrocarbon compounds during colonization of leaves whereas Methylobacterium extorquens relies on methanol metabolism in addition to oxalate metabolism, aerobic anoxygenic photosynthesis and alkanesulfonate utilization. Comparative genomic analyses indicates that utilization of oxalate and alkanesulfonates is widespread among leaf microbiota members whereas, aerobic anoxygenic photosynthesis is almost exclusively found in Methylobacteria. Despite the apparent niche separation between these two strains we also found a relatively small subset of proteins to be coregulated, indicating common mechanisms, underlying successful leaf colonization. Overall, our results reveal for two ubiquitous phyllosphere commensals species-specific adaptations to the host environment and provide evidence for niche separation within the plant microbiota.

  12. QTL analysis of leaf photosynthesis rate and related physiological traits in Brassica napus

    Institute of Scientific and Technical Information of China (English)

    YAN Xing-ying; QU Cun-min; LI Jia-na; CHEN Li; LIU Lie-zhao

    2015-01-01

    Rapeseed (Brassica napus L.) oil is the crucial source of edible oil in China. In addition, it can become a major renewable and sustainable feedstock for biodiesel production in the future. It is known that photosynthesis products are the primary sources for dry matter accumulation in rapeseed. Therefore, increasing the photosynthetic efifciency is desirable for the raise of rapeseed yield. The objective of the present study was to identify the genetic mechanism of photosynthesis based on the description of relationships between different photosynthetic traits and their quantitative trait loci (QTL) by using a recombinant inbred line (RIL) population with 172 lines. Speciifcal y, correlation analysis in this study showed that internal CO2 concentration has negative correlations with other three physiological traits under two different stages. Total y, 11 and 12 QTLs of the four physiological traits measured at the stages 1 and 2 were detected by using a high-density single nu-cleotidepolymorphism (SNP) markers linkage map with composite interval mapping (CIM), respectively. Three co-localized QTLs on A03 were detected at stage 1 with 5, 5, and 10%of the phenotypic variation, respectively. Other two co-localized QTLs were located on A05 at stage 2, which explained up to 12 and 5%of the phenotypic variation, respectively. The results are beneifcial for our understanding of genetic control of photosynthetic physiological characterizations and improvement of rapeseed yield in the future.

  13. Multiyear Multiseasonal Changes in Leaf and Canopy Traits Measured by AVIRIS over Ecosystems with Different Functional Type Characteristics Through the Progressive California Drought 2013-2015

    Science.gov (United States)

    Ustin, S.; Roth, K. L.; Huesca, M.; Casas, A.; Adeline, K.; Drewry, D.; Koltunov, A.; Ramirez, C.

    2015-12-01

    Given the known heterogeneity in ecological processes within plant communities in California, we questioned whether the concept of conventional plant functional types (cPFTs) was adequate to characterize the functionality of the dominant species in these communities. We examined seasonal (spring, summer, fall) airborne AVIRIS and MASTER imagery collected during three years of progressive drought in California, and airborne LiDAR acquired once, for ecosystems that represent a wide range of plant functional types, from annual agriculture and herbaceous perennial wetlands, to forests and shrublands, including broadleaf deciduous and evergreen species and conifer species. These data were used to determine the extent to which changes in canopy chemistry could be detected, quantified, and related to leaf and canopy traits that are indicators of physiological functioning (water content, Leaf Mass Area, total C, N, and pigments (chlorophyll a, b, and carotenoids). At the canopy scale we measured leaf area index, and for forests — species, height, canopy area, DBH, deciduous or evergreen, broadleaf or needleleaf, and gap size. Strong correlations between leaf and canopy traits were predictable and quantifiable from spectroscopy data. Key structural properties of canopy height, biomass and complexity, a measure of spatial and vertical heterogeneity, were predicted by AVIRIS and validated against LiDAR data. Our data supports the hypothesis that optical sensors provide more detailed information about the distribution and variability in leaf and canopy traits related to plant functionality than cPFTs.

  14. Yield, fruit quality traits and leaf nutrient concentration of sapodilla cv ‘Prolific’ grafted onto 16 rootstocks in Puerto Rico

    Science.gov (United States)

    Research on sapodilla has been very limited. A field study was conducted to determine the yield potential, fruit quality traits, leaf nutrient composition and scion/rootstock compatibility of cultivar ‘Prolific’ grafted onto 16 sapodilla rootstocks. For this purpose cultivars ‘Adelaide’, ‘Arcilago’...

  15. Influence of Autism Traits and Executive Functioning on Quality of Life in Children with an Autism Spectrum Disorder

    OpenAIRE

    2015-01-01

    Children with Autism Spectrum Disorders (ASDs) often experience a low Quality of Life (QoL). We studied if IQ, early language development, current autism traits, and daily Executive Functions (EFs) are related to QoL in children (aged 8-12 years) with ASD (N = 120) and typically developing (TD) children (N = 76). Children with ASD showed a lower QoL than TD children. This lower QoL was related to higher levels of autism traits and EF deficits. Moreover, specific autism traits and EFs were rel...

  16. What range of trait levels can the Autism-Spectrum Quotient (AQ) measure reliably? An item response theory analysis.

    Science.gov (United States)

    Murray, Aja Louise; Booth, Tom; McKenzie, Karen; Kuenssberg, Renate

    2016-06-01

    It has previously been noted that inventories measuring traits that originated in a psychopathological paradigm can often reliably measure only a very narrow range of trait levels that are near and above clinical cutoffs. Much recent work has, however, suggested that autism spectrum disorder traits are on a continuum of severity that extends well into the nonclinical range. This implies a need for inventories that can capture individual differences in autistic traits from very high levels all the way to the opposite end of the continuum. The Autism-Spectrum Quotient (AQ) was developed based on a closely related rationale, but there has, to date, been no direct test of the range of trait levels that the AQ can reliably measure. To assess this, we fit a bifactor item response theory model to the AQ. Results suggested that AQ measures moderately low to moderately high levels of a general autistic trait with good measurement precision. The reliable range of measurement was significantly improved by scoring the instrument using its 4-point response scale, rather than dichotomizing responses. These results support the use of the AQ in nonclinical samples, but suggest that items measuring very low and very high levels of autistic traits would be beneficial additions to the inventory. (PsycINFO Database Record

  17. Identification of Quantitative Trait Loci and Water Environmental Interactions for Developmental Behaviors of Leaf greenness in Wheat

    Directory of Open Access Journals (Sweden)

    Delong eYang

    2016-03-01

    Full Text Available The maintenance of leaf greenness in wheat, highly responsible for yield potential and resistance to drought stress, has been proved to be quantitatively inherited and susceptible to interact with environments by traditional genetic analysis. In order to further dissect the developmental genetic behaviors of flag leaf greenness under terminal drought, unconditional and conditional QTL mapping strategies were performed with a mixed linear model in a 120 F8-derived recombinant inbred lines (RILs from two Chinese common wheat cultivars (Longjian 19 × Q9086 in different water environments. A total of 65 additive QTLs (A-QTLs and 42 pairs of epistatic QTLs (AA-QTLs were identified as distribution on almost all 21 chromosomes except 5A, explaining from 0.24 to 3.29 % of the phenotypic variation. Of these, 22 A-QTLs and 25 pairs of AA-QTLs were common in two sets of mapping methods but the others differed. These putative QTLs were essentially characteristic of time- and environmentally-dependent expression patterns. Indeed some loci were expressed at two or more stages, while no single QTL was continually active through whole measuring duration. More loci were detected in early growth periods but most of QTL × water environment interactions (QEIs happened in mid-anaphase, where drought stress was more conducted with negative regulation on QTL expressions. Compared to other genetic components, epistatic effects and additive QEIs effects could be predominant in regulating phenotypic variations during the ontogeny of leaf greenness. Several QTL cluster regions were suggestive of tight linkage or expression pleiotropy in the inheritance of these traits. Some reproducibly-expressed QTLs or common loci consistent with previously detected would be useful to the genetic improvement of staygreen types in wheat through MAS, especially in water-deficit environments.

  18. What is the prevalence of autism spectrum disorder and ASD traits in psychosis? A systematic review.

    Science.gov (United States)

    Kincaid, Debbie L; Doris, Michael; Shannon, Ciaran; Mulholland, Ciaran

    2017-01-07

    There is increasing evidence to suggest both a symptomatic overlap and a clinically significant degree of co-occurrence between Autism Spectrum Disorders (ASD) and psychotic disorders such as schizophrenia but the nature of such relationships remain unclear. We reviewed the literature reporting prevalence rates of Autistic-like Traits (ALTs) and ASD in populations with a diagnosis of schizophrenia or other psychotic disorder. A search of three large databases was conducted and from this seven studies met the criteria for inclusion. The point prevalence rates for ALTs ranged from 9.6% to 61%, whilst the prevalence rates for diagnosed ASD ranged from <1% to 52% across outpatient and inpatient populations. This suggests that prevalence rates of ALTs and ASD in psychosis populations are much higher than in the general population. This has important implications regarding future research, and clinical implications in terms of ensuring that patients receive the most appropriate diagnosis and treatment.

  19. [INVITED] Non-intrusive optical imaging of face to probe physiological traits in Autism Spectrum Disorder

    Science.gov (United States)

    Samad, Manar D.; Bobzien, Jonna L.; Harrington, John W.; Iftekharuddin, Khan M.

    2016-03-01

    Autism Spectrum Disorders (ASD) can impair non-verbal communication including the variety and extent of facial expressions in social and interpersonal communication. These impairments may appear as differential traits in the physiology of facial muscles of an individual with ASD when compared to a typically developing individual. The differential traits in the facial expressions as shown by facial muscle-specific changes (also known as 'facial oddity' for subjects with ASD) may be measured visually. However, this mode of measurement may not discern the subtlety in facial oddity distinctive to ASD. Earlier studies have used intrusive electrophysiological sensors on the facial skin to gauge facial muscle actions from quantitative physiological data. This study demonstrates, for the first time in the literature, novel quantitative measures for facial oddity recognition using non-intrusive facial imaging sensors such as video and 3D optical cameras. An Institutional Review Board (IRB) approved that pilot study has been conducted on a group of individuals consisting of eight participants with ASD and eight typically developing participants in a control group to capture their facial images in response to visual stimuli. The proposed computational techniques and statistical analyses reveal higher mean of actions in the facial muscles of the ASD group versus the control group. The facial muscle-specific evaluation reveals intense yet asymmetric facial responses as facial oddity in participants with ASD. This finding about the facial oddity may objectively define measurable differential markers in the facial expressions of individuals with ASD.

  20. The Influence of Personality Traits on Emotion Expression in Bulimic Spectrum Disorders: A Pilot Study.

    Science.gov (United States)

    Giner-Bartolomé, Cristina; Steward, Trevor; Wolz, Ines; Jiménez-Murcia, Susana; Granero, Roser; Tárrega, Salomé; Fernández-Formoso, José Antonio; Soriano-Mas, Carles; Menchón, José M; Fernández-Aranda, Fernando

    2016-07-01

    Facial expressions are critical in forming social bonds and in signalling one's emotional state to others. In eating disorder patients, impairments in facial emotion recognition have been associated with eating psychopathology severity. Little research however has been carried out on how bulimic spectrum disorder (BSD) patients spontaneously express emotions. Our aim was to investigate emotion expression in BSD patients and to explore the influence of personality traits. Our study comprised 28 BSD women and 15 healthy controls. Facial expressions were recorded while participants played a serious video game. Expressions of anger and joy were used as outcome measures. Overall, BSD participants displayed less facial expressiveness than controls. Among BSD women, expressions of joy were positively associated with reward dependence, novelty seeking and self-directedness, whereas expressions of anger were associated with lower self-directedness. Our findings suggest that specific personality traits are associated with altered emotion facial expression in patients with BSD. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

  1. Are autistic traits measured equivalently in individuals with and without an autism spectrum disorder? An invariance analysis of the Autism Spectrum Quotient Short Form.

    Science.gov (United States)

    Murray, Aja L; Booth, Tom; McKenzie, Karen; Kuenssberg, Renate; O'Donnell, Michael

    2014-01-01

    It is common to administer measures of autistic traits to those without autism spectrum disorders (ASDs) with, for example, the aim of understanding autistic personality characteristics in non-autistic individuals. Little research has examined the extent to which measures of autistic traits actually measure the same traits in the same way across those with and without an ASD. We addressed this question using a multi-group confirmatory factor invariance analysis of the Autism Quotient Short Form (AQ-S: Hoekstra et al. in J Autism Dev Disord 41(5):589-596, 2011) across those with (n = 148) and without (n = 168) ASD. Metric variance (equality of factor loadings), but not scalar invariance (equality of thresholds), held suggesting that the AQ-S measures the same latent traits in both groups, but with a bias in the manner in which trait levels are estimated. We, therefore, argue that the AQ-S can be used to investigate possible causes and consequences of autistic traits in both groups separately, but caution is due when combining or comparing levels of autistic traits across the two groups.

  2. Quantitative trait loci analysis of chlorophyll content for flag leaf in rice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Chlorophyll contents are one of important physiological traits, which affect photosynthesis in plants. There were significant differences in chlorophyll contents between Zhaiyeqing 8(ZYQ 8), an indica variety and Jingxi 17(JX 17), a japonica variety (Table 1). In 117 DH lines of the cross of ZYQ 8/ JX 17, these parameters distributed conTwo neutral alleles of improving male gamete abortion in indica-japonica hybrid rice LU Chuangen and ZOU Jiangshi, Jiangsu Acad of Agri Sci, Nanjing 210014, China

  3. Community assembly and functional leaf traits mediate precipitation use efficiency of alpine grasslands along environmental gradients on the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Shaowei Li

    2016-11-01

    Full Text Available The alpine grasslands on the Tibetan Plateau are sensitive and vulnerable to climate change. However, it is still unknown how precipitation use efficiency (PUE, the ratio of aboveground net primary productivity (ANPP to precipitation, is related to community assembly of plant species, functional groups or traits for the Tibetan alpine grasslands along actual environmental gradients. We conducted a multi-site field survey at grazing-excluded pastures across meadow, steppe and desert-steppe to measure aboveground biomass (AGB in August, 2010. We used species richness (SR, the Shannon diversity index, and cover-weighted functional group composition (FGC of 1-xerophytes, 2-mesophytes, and 3-hygrophytes to describe community assembly at the species level; and chose community-level leaf area index (LAIc, specific leaf area (SLAc, and species-mixed foliar δ13C to quantify community assembly at the functional trait level. Our results showed that PUE decreased with increasing accumulated active temperatures (AccT when daily temperature average is higher than 5 °C, but increased with increasing climatic moisture index (CMI, which was demined as the ratio of growing season precipitation (GSP to AccT. We also found that PUE increased with increasing SR, the Shannon diversity index, FGC and LAIc, decreased with increasing foliar δ13C, and had no relation with SLAc at the regional scale. Neither soil total nitrogen (STN nor organic carbon has no influence on PUE at the regional scale. The community assembly of the Shannon index, LAIc and SLAc together accounted for 46.3% of variance in PUE, whilst CMI accounted for 47.9% of variance in PUE at the regional scale. This implies that community structural properties and plant functional traits can mediate the sensitivity of alpine grassland productivity in response to climate change. Thus, a long-term observation on community structural and functional changes is recommended for better understanding the response

  4. Sex Differences in the Default Mode Network with Regard to Autism Spectrum Traits: A Resting State fMRI Study.

    Directory of Open Access Journals (Sweden)

    Minyoung Jung

    Full Text Available Autism spectrum traits exist on a continuum and are more common in males than in females, but the basis for this sex difference is unclear. To this end, the present study draws on the extreme male brain theory, investigating the relationship between sex difference and the default mode network (DMN, both known to be associated with autism spectrum traits. Resting-state functional magnetic resonance imaging (MRI was carried out in 42 females (mean age ± standard deviation, 22.4 ± 4.2 years and 43 males (mean age ± standard deviation, 23.8 ± 3.9 years with typical development. Using a combination of different analyses (viz., independent component analysis (ICA, fractional amplitude of low-frequency fluctuation (fALFF, regional homogeneity (ReHo, and seed-based analyses, we examined sex differences in the DMN and the relationship to autism spectrum traits as measured by autism-spectrum quotient (AQ scores. We found significant differences between female and male subjects in DMN brain regions, with seed-based analysis revealing a significant negative correlation between default-mode resting state functional connectivity of the anterior medial prefrontal cortex seed (aMPFC and AQ scores in males. However, there were no relationships between DMN sex differences and autism spectrum traits in females. Our findings may provide important insight into the skewed balance of functional connectivity in males compared to females that could serve as a potential biomarker of the degree of autism spectrum traits in line with the extreme male brain theory.

  5. Sheldon spectrum and the plankton paradox: two sides of the same coin-a trait-based plankton size-spectrum model.

    Science.gov (United States)

    Cuesta, José A; Delius, Gustav W; Law, Richard

    2017-05-25

    The Sheldon spectrum describes a remarkable regularity in aquatic ecosystems: the biomass density as a function of logarithmic body mass is approximately constant over many orders of magnitude. While size-spectrum models have explained this phenomenon for assemblages of multicellular organisms, this paper introduces a species-resolved size-spectrum model to explain the phenomenon in unicellular plankton. A Sheldon spectrum spanning the cell-size range of unicellular plankton necessarily consists of a large number of coexisting species covering a wide range of characteristic sizes. The coexistence of many phytoplankton species feeding on a small number of resources is known as the Paradox of the Plankton. Our model resolves the paradox by showing that coexistence is facilitated by the allometric scaling of four physiological rates. Two of the allometries have empirical support, the remaining two emerge from predator-prey interactions exactly when the abundances follow a Sheldon spectrum. Our plankton model is a scale-invariant trait-based size-spectrum model: it describes the abundance of phyto- and zooplankton cells as a function of both size and species trait (the maximal size before cell division). It incorporates growth due to resource consumption and predation on smaller cells, death due to predation, and a flexible cell division process. We give analytic solutions at steady state for both the within-species size distributions and the relative abundances across species.

  6. Influence of autism traits and executive functioning on quality of life in children with an autism spectrum disorder

    NARCIS (Netherlands)

    de Vries, M.; Geurts, H.

    2015-01-01

    Children with Autism Spectrum Disorders (ASDs) often experience a low Quality of Life (QoL). We studied if IQ, early language development, current autism traits, and daily Executive Functions (EFs) are related to QoL in children (aged 8-12 years) with ASD (N = 120) and typically developing (TD)

  7. Parents' State and Trait Anxiety: Relationships with Anxiety Severity and Treatment Response in Adolescents with Autism Spectrum Disorders

    Science.gov (United States)

    Conner, Caitlin M.; Maddox, Brenna B.; White, Susan W.

    2013-01-01

    Comorbid anxiety is common among children with Autism Spectrum Disorder (ASD), and parents of children with ASD are more likely to have anxiety disorders. This study investigated the relationship between parents' state and trait anxiety and parent-reported internalizing and externalizing symptoms among adolescents (n = 30) with ASD, as well…

  8. Influence of autism traits and executive functioning on quality of life in children with an autism spectrum disorder

    NARCIS (Netherlands)

    de Vries, M.; Geurts, H.

    2015-01-01

    Children with Autism Spectrum Disorders (ASDs) often experience a low Quality of Life (QoL). We studied if IQ, early language development, current autism traits, and daily Executive Functions (EFs) are related to QoL in children (aged 8-12 years) with ASD (N = 120) and typically developing (TD) chil

  9. Parents' State and Trait Anxiety: Relationships with Anxiety Severity and Treatment Response in Adolescents with Autism Spectrum Disorders

    Science.gov (United States)

    Conner, Caitlin M.; Maddox, Brenna B.; White, Susan W.

    2013-01-01

    Comorbid anxiety is common among children with Autism Spectrum Disorder (ASD), and parents of children with ASD are more likely to have anxiety disorders. This study investigated the relationship between parents' state and trait anxiety and parent-reported internalizing and externalizing symptoms among adolescents (n = 30) with ASD, as well…

  10. Personality Traits, Autobiographical Memory and Knowledge of Self and Others: A Comparative Study in Young People with Autism Spectrum Disorder

    Science.gov (United States)

    Robinson, Sally; Howlin, Patricia; Russell, Ailsa

    2017-01-01

    The relationship between dissociable components of autobiographical memory (e.g. semantic personality traits and episodic memory retrieval) and other cognitive skills that are proposed to enable one to develop a sense of self (e.g. introspection) have not previously been explored for children with autism spectrum disorder. This study compared…

  11. Influence of autism traits and executive functioning on quality of life in children with an autism spectrum disorder

    NARCIS (Netherlands)

    de Vries, M.; Geurts, H.

    2015-01-01

    Children with Autism Spectrum Disorders (ASDs) often experience a low Quality of Life (QoL). We studied if IQ, early language development, current autism traits, and daily Executive Functions (EFs) are related to QoL in children (aged 8-12 years) with ASD (N = 120) and typically developing (TD) chil

  12. Using the Autism-Spectrum Quotient to Measure Autistic Traits in Anorexia Nervosa: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Westwood, Heather; Eisler, Ivan; Mandy, William; Leppanen, Jenni; Treasure, Janet; Tchanturia, Kate

    2016-03-01

    Interest in the link between Autism Spectrum Disorder (ASD) and Anorexia Nervosa (AN) has led to estimates of the prevalence of autistic traits in AN. This systematic review and meta-analysis assessed the use of the Autism-Spectrum Quotient (AQ) or abbreviated version (AQ-10) to examine whether patients with AN have elevated levels of autistic traits. Seven studies were identified and subsequent meta-analysis indicated that those with AN appear to have significant difficulties of a manner characteristic of ASD, relative to controls. Whilst this analysis supports previous indications of higher prevalence of ASD in AN, the aetiology of these traits remains unclear. Studies using more robust clinical measures of ASD within AN are needed to confirm what self-report measures appear to show.

  13. Do the Traits of Autism-Spectrum Overlap with Those of Schizophrenia or Obsessive-Compulsive Disorder in the General Population?

    Science.gov (United States)

    Wakabayashi, Akio; Baron-Cohen, Simon; Ashwin, Chris

    2012-01-01

    Social and communicative deficits, restricted interests and repetitive behaviors are diagnostic features of autism spectrum disorders (ASD). The present study examined the relationship between autistic characteristics and schizophrenia-spectrum traits as well as between autistic characteristics and obsessive-compulsive traits in typically…

  14. Low temperature wheat germplasm and its leaf photosynthetic traits and structure characteristics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Songwu; MIAO Fang; WANG Changfa

    2004-01-01

    Low temperature germplasm with constant low plant temperature was found in the nature through a long-time observation on wheat canopy temperature and traits; correspondingly, high temperature germplasm with constant high plant temperature also exists. Compared with the high temperature germplasm, the chlorophyll content and the net photosynthetic rate of the three functional leaves on the top of the low temperature wheat germplasm are higher and the structure tends to be more complicated, which is characterized by smaller mesophyll cells and more closely arranged cell layers, more and denser chloroplasts with thick stroma, more granas and well developed grana lamellae, a larger vascular bundle area with smaller interspace. All these characteristics embody the consistency of structure and function and provide the theoretical bases for looking for and cultivating the new low temperature materials in agricultural practice.

  15. Enhanced monsoon precipitation and nitrogen deposition affect leaf traits and photosynthesis differently in spring and summer in the desert shrub Larrea tridentata.

    Science.gov (United States)

    Barker, D H; Vanier, C; Naumburg, E; Charlet, T N; Nielsen, K M; Newingham, B A; Smith, S D

    2006-01-01

    Leaf-level CO2 assimilation (A(area)) can largely be predicted from stomatal conductance (g(s)), leaf morphology (SLA) and nitrogen (N) content (N(area)) in species across biomes and functional groups. The effects of simulated global change scenarios, increased summer monsoon rain (+H2O), N deposition (+N) and the combination (+H2O +N), were hypothesized to affect leaf trait-photosynthesis relationships differently in the short- and long-term for the desert shrub Larrea tridentata. During the spring, +H2O and +H2O +N plants had lower A(area) and g(s), but similar shoot water potential (Psi(shoot)) compared with control and +N plants; differences in A(area) were attributed to lower leaf N(area) and g(s). During the summer, +H2O and +H2O +N plants displayed higher A(area) than control and +N plants, which was attributed to higher Psi(shoot), g(s) and SLA. Throughout the year, A(area) was strongly correlated with g(s) but weakly correlated with leaf N(area) and SLA. We concluded that increased summer monsoon had a stronger effect on the performance of Larrea than increased N deposition. In the short term, the +H2O and +H2O +N treatments were associated with increasing A(area) in summer, but also with low leaf N(area) and lower A(area) in the long term the following spring.

  16. Identification of quantitative trait loci for the dead leaf rate and the seedling dead rate under alkaline stress in rice

    Institute of Scientific and Technical Information of China (English)

    Dongling Qi; Guizhen Guo; Myung-chul Lee; Junguo Zhang; Guilan Cao; Sanyuan Zhang; Seok-cheol Suh; Qingyang Zhou; Longzhi Han

    2008-01-01

    The quantitative trait loci (QTLs) for the dead leaf rate (DLR) and the dead seedling rate (DSR) at the different rice growing periods after transplanting under alkaline stress were identified using an F2:3 population, which included 200 individuals and lines derived from a cross betweea two japonica rice cultivars Gaochan 106 and Changbai 9 with microsatellite markers. The DLR detected at 20 days to 62 days after transplanting under alkaline stress showed continuous normal or near normal distributions in F3 lines, which was the quantita-tive trait controlled by multiple genes. The DSR showed a continuous distribution with 3 or 4 peaks and was the quantitative trait con-trolled by main and multiple genes when rice was grown for 62 days after transplanting under alkaline stress. Thirteen QTLs associated with DLR were detected at 20 days to 62 days after transplanting under alkaline stress. Among these, qDLR9-2 located in RM5786-RMI60 on chromosome 9 was detected at 34 days, 41 days, 48 days, 55 days, and 62 days, respectively; qDLR4 located in RM3524-RM3866 on chromosome 4 was detected at 34 days, 41 days, and 48 days, respectively; qDLR7-1 located in RM3859-RM320 on chromosome 7 was detected at 20 days and 27 days; and qDLR6-2 in RM1340-RM5957 on chromosome 6 was detected at 55 days and 62 days, respectively. The alleles of both qDLR9-2 and qDLR4 were derived from alkaline sensitive parent "Gaochan 106". The alleles of both qDLR7-1 and qDLR6-2 were from alkaline tolerant parent Changbai 9. These geue actions showed dominance and over dominance primarily. Six QTLs associated with DSR were detected at 62 days after transplanting under alkaline stress. Among these, qDSR6-2 and qDSR8 were located in RM1340-RM5957 on chromosome 6 and in RM3752-RM404 on chromosome 8, respectively, which were asso-ciated with DSR and accounted for 20.32% and 18.86% of the observed phenotypic variation, respectively; qDSR11-2 and qDSR11-3 were located in RM536-RM479 and RM2596-RM286 on

  17. Effects of atmospheric CO2 concentration, irradiance, and soil nitrogen availability on leaf photosynthetic traits of Polygonum sachalinense around natural CO2 springs in northern Japan.

    Science.gov (United States)

    Osada, Noriyuki; Onoda, Yusuke; Hikosaka, Kouki

    2010-09-01

    Long-term exposure to elevated CO2 concentration will affect the traits of wild plants in association with other environmental factors. We investigated multiple effects of atmospheric CO2 concentration, irradiance, and soil N availability on the leaf photosynthetic traits of a herbaceous species, Polygonum sachalinense, growing around natural CO2 springs in northern Japan. Atmospheric CO2 concentration and its interaction with irradiance and soil N availability affected several leaf traits. Leaf mass per unit area increased and N per mass decreased with increasing CO2 and irradiance. Leaf N per area increased with increasing soil N availability at higher CO2 concentrations. The photosynthetic rate under growth CO2 conditions increased with increasing irradiance and CO2, and with increasing soil N at higher CO2 concentrations. The maximal velocity of ribulose 1,5-bisphosphate carboxylation (V (cmax)) was affected by the interaction of CO2 and soil N, suggesting that down-regulation of photosynthesis at elevated CO2 was more evident at lower soil N availability. The ratio of the maximum rate of electron transport to V (cmax) (J (max)/V (cmax)) increased with increasing CO2, suggesting that the plants used N efficiently for photosynthesis at high CO2 concentrations by changes in N partitioning. To what extent elevated CO2 influenced plant traits depended on other environmental factors. As wild plants are subject to a wide range of light and nutrient availability, our results highlight the importance of these environmental factors when the effects of elevated CO2 on plants are evaluated.

  18. Influence of Autism Traits and Executive Functioning on Quality of Life in Children with an Autism Spectrum Disorder

    Science.gov (United States)

    de Vries, Marieke; Geurts, Hilde

    2015-01-01

    Children with Autism Spectrum Disorders (ASDs) often experience a low Quality of Life (QoL). We studied if IQ, early language development, current autism traits, and daily Executive Functions (EFs) are related to QoL in children (aged 8-12 years) with ASD (N = 120) and typically developing (TD) children (N = 76). Children with ASD showed a lower…

  19. Two alternative recessive quantitative trait loci influence resistance to spring black stem and leaf spot in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Oliver Richard P

    2008-03-01

    Full Text Available Abstract Background Knowledge of the genetic basis of plant resistance to necrotrophic pathogens is incomplete and has been characterised in relatively few pathosystems. In this study, the cytology and genetics of resistance to spring black stem and leaf spot caused by Phoma medicaginis, an economically important necrotrophic pathogen of Medicago spp., was examined in the model legume M. truncatula. Results Macroscopically, the resistant response of accession SA27063 was characterised by small, hypersensitive-like spots following inoculation while the susceptible interaction with accessions A17 and SA3054 showed necrotic lesions and spreading chlorosis. No unique cytological differences were observed during early infection (2 populations segregating for resistance to spring black stem and leaf spot were established between SA27063 and the two susceptible accessions, A17 and SA3054. The cross between SA27063 and A17 represented a wider cross than between SA27063 and SA3054, as evidenced by higher genetic polymorphism, reduced fertility and aberrant phenotypes of F2 progeny. In the SA27063 × A17 F2 population a highly significant quantitative trait locus (QTL, LOD = 7.37; P Phoma medicaginis one (rnpm1 genetically mapped to the top arm of linkage group 4 (LG4. rnpm1 explained 33.6% of the phenotypic variance in the population's response to infection depicted on a 1–5 scale and was tightly linked to marker AW256637. A second highly significant QTL (LOD = 6.77; P rnpm2, was located on the lower arm of LG8 in the SA27063 × SA3054 map. rnpm2 explained 29.6% of the phenotypic variance and was fine mapped to a 0.8 cM interval between markers h2_16a6a and h2_21h11d. rnpm1 is tightly linked to a cluster of Toll/Interleukin1 receptor-nucleotide binding site-leucine-rich repeat (TIR-NBS-LRR genes and disease resistance protein-like genes, while no resistance gene analogues (RGAs are apparent in the genomic sequence of the reference accession A17 at the

  20. Autistic traits in male and female students and individuals with high functioning autism spectrum disorders measured by the Polish version of the Autism-Spectrum Quotient.

    Directory of Open Access Journals (Sweden)

    Ewa Pisula

    Full Text Available So far no standardized screening instrument for autism spectrum disorders for adults has been developed in Poland. The main aim of the study was to explore the properties of the Polish version of the Autism-Spectrum Quotient (AQ, especially its reliability and discriminating power. The second purpose was to establish whether the pattern of sex and area of study differences in the amount of autistic traits found in other countries also exist in Poland. The groups in the study included students (n = 2819, adults with ASD (n = 60 and a non-clinical sample (n = 60 matched with the ASD group for age, sex, education and place of residence. The Polish version of AQ proved to be reliable, although--as in studies conducted in other countries--the internal consistency coefficients for subscales (with exception for social skill were low. ASD diagnosis was the most powerful determinant of AQ scores. Sex differences in autistic traits and a relationship between autistic traits and area of study were found.

  1. Leaf traits and photosynthetic responses of Betula pendula saplings to a range of ground-level ozone concentrations at a range of nitrogen loads.

    Science.gov (United States)

    Harmens, Harry; Hayes, Felicity; Sharps, Katrina; Mills, Gina; Calatayud, Vicent

    2017-04-01

    Ground-level ozone (O3) concentrations and atmospheric nitrogen (N) deposition rates have increased strongly since the 1950s. Rising ground-level O3 concentrations and atmospheric N deposition both affect plant physiology and growth, however, impacts have often been studied in isolation rather than in combination. In addition, studies are often limited to a control treatment and one or two elevated levels of ozone and/or nitrogen supply. In the current study, three-year old Betula pendula saplings were exposed to seven different O3 profiles (24h mean O3 concentration of 36-68ppb in 2013, with peaks up to an average of 105ppb) in precision-controlled hemispherical glasshouses (solardomes) and four different N loads (10, 30, 50 or 70kgNha(-1)y(-1)) in 2012 and 2013. Here we report on the effects of enhanced O3 concentrations and N load on leaf traits and gas exchange in leaves of varying age and developmental stage in 2013. The response of leaf traits to O3 (but not N) vary with leaf developmental stage. For example, elevated O3 did not affect the chlorophyll content of the youngest fully expanded leaf, but it reduced the chlorophyll content and photosynthetic parameters in aging leaves, relatively more so later than earlier in the growing season. Elevated O3 enhanced the N content of senesced leaves prior to leaf fall, potentially affecting subsequent N cycling in the soil. Enhanced N generally stimulated the chlorophyll content and photosynthetic capacity. Whilst elevated O3 reduced the light-saturated rate of photosynthesis (Asat) in aging leaves, it did not affect stomatal conductance (gs). This suggests that photosynthesis and gs are not closely coupled at elevated O3 under-light saturating conditions. We did not observe any interactions between O3 and N regarding photosynthetic parameters (Vc,max, Jmax, Asat), chlorophyll content, gs, N content in senesced leaves and leaf number. Hence, the sensitivity of these leaf traits to O3 in young silver birch trees is

  2. Crown traits of coniferous trees and their relation to shade tolerance can differ with leaf type: a biophysical demonstration using computed tomography scanning data.

    Science.gov (United States)

    Dutilleul, Pierre; Han, Liwen; Valladares, Fernando; Messier, Christian

    2015-01-01

    Plant light interception and shade tolerance are intrinsically related in that they involve structural, morphological and physiological adaptations to manage light capture for photosynthetic utilization, in order to sustain survival, development and reproduction. At the scale of small-size trees, crown traits related to structural geometry of branching pattern and space occupancy through phyllotaxis can be accurately evaluated in 3D, using computed tomography (CT) scanning data. We demonstrate this by scrutinizing the crowns of 15 potted miniature conifers of different species or varieties, classified in two groups based on leaf type (10 needlelike, 5 scalelike); we also test whether mean values of crown traits measured from CT scanning data and correlations with a shade tolerance index (STI) differ between groups. Seven crown traits, including fractal dimensions (FD1: smaller scales, FD2: larger scales) and leaf areas, were evaluated for all 15 miniature conifers; an average silhouette-to-total-area ratio was also calculated for each of the 10 needlelike-leaf conifers. Between-group differences in mean values are significant (P < 0.05) for STI, FD1, FD2, and the average leaf area displayed (ĀD). Between-group differences in sign and strength of correlations are observed. For example, the correlation between STI and FD1 is negative and significant (P < 0.10) for the needlelike-leaf group, but is positive and significant (P < 0.05) for the miniature conifers with scalelike leaves, which had lower STI and higher FD1 on average in our study; the positive correlation between STI and ĀD is significant (P < 0.05) for the scalelike-leaf group, and very moderate for the needlelike-leaf one. A contrasting physical attachment of the leaves to branches may explain part of the between-group differences. Our findings open new avenues for the understanding of fundamental plant growth processes; the information gained could be included in a multi-scale approach to tree crown

  3. A Comparative Study of Proteolytic Mechanisms during Leaf Senescence of Four Genotypes of Winter Oilseed Rape Highlighted Relevant Physiological and Molecular Traits for NRE Improvement

    Directory of Open Access Journals (Sweden)

    Alexandra Girondé

    2015-12-01

    Full Text Available Winter oilseed rape is characterized by a low N use efficiency related to a weak leaf N remobilization efficiency (NRE at vegetative stages. By investigating the natural genotypic variability of leaf NRE, our goal was to characterize the relevant physiological traits and the main protease classes associated with an efficient proteolysis and high leaf NRE in response to ample or restricted nitrate supply. The degradation rate of soluble proteins and D1 protein (a thylakoid-bound protein were correlated to N remobilization, except for the genotype Samouraï which showed a low NRE despite high levels of proteolysis. Under restricted nitrate conditions, high levels of soluble protein degradation were associated with serine, cysteine and aspartic proteases at acidic pH. Low leaf NRE was related to a weak proteolysis of both soluble and thylakoid-bound proteins. The results obtained on the genotype Samouraï suggest that the timing between the onset of proteolysis and abscission could be a determinant. The specific involvement of acidic proteases suggests that autophagy and/or senescence-associated vacuoles are implicated in N remobilization under low N conditions. The data revealed that the rate of D1 degradation could be a relevant indicator of leaf NRE and might be used as a tool for plant breeding.

  4. Resource quality affects weapon and testis size and the ability of these traits to respond to selection in the leaf-footed cactus bug, Narnia femorata.

    Science.gov (United States)

    Sasson, Daniel A; Munoz, Patricio R; Gezan, Salvador A; Miller, Christine W

    2016-04-01

    The size of weapons and testes can be central to male reproductive success. Yet, the expression of these traits is often extremely variable. Studies are needed that take a more complete organism perspective, investigating the sources of variation in both traits simultaneously and using developmental conditions that mimic those in nature. In this study, we investigated the components of variation in weapon and testis sizes using the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae) on three natural developmental diets. We show that the developmental diet has profound effects on both weapon and testis expression and scaling. Intriguingly, males in the medium-quality diet express large weapons but have relatively tiny testes, suggesting complex allocation decisions. We also find that heritability, evolvability, and additive genetic variation are highest in the high-quality diet for testis and body mass. This result suggests that these traits may have an enhanced ability to respond to selection during a small window of time each year when this diet is available. Taken together, these results illustrate that normal, seasonal fluctuations in the nutritional environment may play a large role in the expression of sexually selected traits and the ability of these traits to respond to selection.

  5. mizer: an R package for multispecies, trait-based and community size spectrum ecological modelling

    DEFF Research Database (Denmark)

    Scott, Finlay; Blanchard, Julia L.; Andersen, Ken Haste

    2014-01-01

    1. Size spectrum ecological models are representations of a community of individuals which grow and change trophic level. A key emergent feature of these models is the size spectrum; the total abundance of all individuals that scales negatively with size. The models we focus on are designed...

  6. Autistic Traits in Couple Dyads as a Predictor of Anxiety Spectrum Symptoms

    Science.gov (United States)

    Lau, Winnie Yu-Pow; Gau, Susan Shur-Fen; Chiu, Yen-Nan; Wu, Yu-Yu

    2014-01-01

    The link between parental autistic tendency and anxiety symptoms was studied in 491 Taiwanese couples raising biological children with autism spectrum disorders (ASDs). Parental autistic tendency as measured by Autism Spectrum Quotient (AQ) was associated with anxiety symptoms across all domains. Large effect sizes were found in social phobia and…

  7. Leaf-trait responses to irrigation of the endemic fog-oasis tree Myrcianthes ferreyrae: can a fog specialist benefit from regular watering?

    Science.gov (United States)

    Ramírez, David A; Balaguer, Luis; Mancilla, Rosa; González, Virginia; Coaguila, Daniel; Talavera, Carmelo; Villegas, Luis; Ortega, Aldo; Jiménez, Percy; Moreno, José M

    2012-01-01

    Myrcianthes ferreyrae is an endemic, endangered species, with a small number of individuals located only in hyperarid, fog-oases known as lomas along the Peruvian desert in southern Peru, where fog is the main source of water. Following centuries of severe deforestation, reforestation with this native species was conducted in the Atiquipa lomas, Arequipa-Perú. On five slopes, five 2-year-old seedlings were irrigated monthly with water trapped by raschel-mesh fog collectors, supplementing natural rainfall with 0, 20, 40, 60 and 80 mm month(-1) from February to August 2008. We measured plant growth, increment in basal diameter, height and five leaf traits: leaf mass area (LMA), leaf carbon isotope composition (δ(13)C), nitrogen per leaf area, total leaf carbon and stomatal density; which are indicative of the physiological changes resulting from increased water supply. Plant growth rates, estimated from the variation of either shoot basal diameter or maximum height, were highly correlated with total biomass. Only LMA and δ(13)C were higher in irrigated than in control plants, but we found no further differences among irrigation treatments. This threshold response suggests an on-off strategy fitted to exploit pulses of fog water, which are always limited in magnitude in comparison with natural rain. The absence of a differential response to increased water supply is in agreement with the low phenotypic plasticity expected in plants from very stressful environments. Our results have practical implications for reforestation projects, since irrigating with 20 mm per month is sufficient to achieve the full growth capacity of this species.

  8. Interactive effects of supplemental UV-B and temperature in European aspen seedlings: Implications for growth, leaf traits, phenolic defense and associated organisms.

    Science.gov (United States)

    Randriamanana, Tendry R; Lavola, Anu; Julkunen-Tiitto, Riitta

    2015-08-01

    Past studies reveal opposite effects of elevated UV-B and temperature on plant growth and concentrations of UV-B absorbing compounds, yet few studies have dealt with the combined and interactive effects of these two climate change factors on woody dioecious plants. We investigated the interactive effects of UV-B and temperature treatments on growth, leaf traits and phenolic concentrations in Populus tremula L. (European aspen) seedlings. We also considered the consequences of these effects on their associated organisms: herbivorous insects, rust pathogens, the presence of endophytic fungi and whether or not the responses differ between genders and genotypes. Supplemental temperature and UV-B were modulated to +2 °C and +30.77% above ambient conditions, respectively. Warming increased growth, photosynthesis and foliar nitrogen concentration but reduced leaf thickness and phenolic concentrations. On the other hand, supplemental UV-B increased total phenolic glycosides, mainly flavonols and phenolic acids, and partially counteracted the positive effects of warming on growth. Fast growing genotypes were less susceptible to the growth-reducing effect of combined UVB + T, less infected with rust disease and less prone to insect damage probably due to their higher salicylate and lower nitrogen concentrations. Under ambient temperature, the males of European aspen were taller and had bigger leaves than the females, while under elevated temperature, females grew bigger and, under UV-B, had more tremulacin than males. The multiple interactive effects of UV-B and temperature on growth, leaf traits and phenolic compounds, highlight the importance of multifactor experiments as a realistic predictor of plant responses to climate change.

  9. Comparison of leaf functional traits in different forest communities in Mt. Dongling of Beijing%东灵山地区不同森林群落叶功能性状比较

    Institute of Scientific and Technical Information of China (English)

    宝乐; 刘艳红

    2009-01-01

    Plant functional trait has been a hot topic in ecological research in recent years. Of which leaf functional trait is most closely related with biomass, resource acquisition and utilization, and resource use efficiency of plants. In this study, relationships among different leaf functional traits and between leaf functional traits and topographic factors were studied in Mt. Dongling of Beijing, and comparisons of leaf functional traits were made among different forest communities. Pearson Correlation analysis showed that leaf dry matter content (LDMC) was negatively correlated with specific leaf area (SLA),leaf nitrogen content (LNC),leaf phosphorus content (LPC)and leaf kalium content (LKC);Leaf size was positively correlated with leaf thickness;SLA had positive correlation with LNC, LPC and LKC;LNC had positive correlation with LPC and LKC;LPC was positively correlated with LKC. Based on grey relational grade analysis, elevation was the most influential topographic factor for leaf size, LNC and LKC;LDMC and leaf thickness was most affected by steepness of slope;and slope position affected SLA and LPC the most. According to the SLA and LDMC of tree layer, the five communities can be classified into three groups: the first group consists of Betula dahurica and Populus davidiana, the second group contains mainly Quercus liaotungensis, and the third group consists of Juglans mandshurica and Tilia mandshurica. The community classification is consistent with the classification by dominant plants of the zonal vegetation, LDMC and SLA are the leaf functional traits that reflect the differences between communities best.%植物功能性状(plant functional trait)是近年来生态学研究的热点.其中叶功能性状(leaf functional trait)与植株生物量和植物对资源的获得、利用及利用效率的关系最为密切.研究了东灵山地区叶功能性状之间的关系、叶功能性状与地形因子的关系,并对不同群落叶功能

  10. Relationship between leaf litter identity, expression of cytochrome P450 genes and life history traits of Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Kim, Chang-Hyun; Muturi, Ephantus J

    2012-04-01

    The role of toxic component of leaf litter in mediating the outcome of mosquito species interactions is not well documented. To examine the effect of leaf litter toxins on mosquito performance and interspecific interactions, we reared monospecific and heterospecific cultures of Aedes aegypti L. and Aedes albopictus Skuse larvae in microcosms with one of five leaf species and measured the expression of five cytochrome P450 genes and life history traits of the two mosquito species. For both mosquito species, survival to adulthood was significantly higher in black alder, black walnut, and cypress infusion compared to sugar maple and eastern white pine infusion. In pine but not in other leaf treatments, the presence of A. albopictus had significant positive effects on A. aegypti wing length and development time to adulthood. A. albopictus from heterospecific cultures were larger than those from monospecific cultures and were smaller and took longer to develop in pine and sugar maple infusions than in the other infusions. Up regulation of CYP6Z6 and CYP9M9 in A. aegypti and A. albopictus respectively appeared to be closely associated with the deleterious effects of sugar maple infusion on mosquito performance as was the down regulation of CYP6N12 (in A. aegypti) and lack of induction of CYP6Z6 and CYP9M9 (in A. aegypti and A. albopictus respectively) in pine infusion. Results suggest that metabolic capabilities that enable the two species to tolerate natural xenobiotics are associated with a fitness cost. Published by Elsevier B.V.

  11. The spectrum of the non-rapid eye movement sleep electroencephalogram following total sleep deprivation is trait-like.

    Science.gov (United States)

    Tarokh, Leila; Rusterholz, Thomas; Achermann, Peter; Van Dongen, Hans P A

    2015-08-01

    The sleep electroencephalogram (EEG) spectrum is unique to an individual and stable across multiple baseline recordings. The aim of this study was to examine whether the sleep EEG spectrum exhibits the same stable characteristics after acute total sleep deprivation. Polysomnography (PSG) was recorded in 20 healthy adults across consecutive sleep periods. Three nights of baseline sleep [12 h time in bed (TIB)] following 12 h of wakefulness were interleaved with three nights of recovery sleep (12 h TIB) following 36 h of sustained wakefulness. Spectral analysis of the non-rapid eye movement (NREM) sleep EEG (C3LM derivation) was used to calculate power in 0.25 Hz frequency bins between 0.75 and 16.0 Hz. Intraclass correlation coefficients (ICCs) were calculated to assess stable individual differences for baseline and recovery night spectra separately and combined. ICCs were high across all frequencies for baseline and recovery and for baseline and recovery combined. These results show that the spectrum of the NREM sleep EEG is substantially different among individuals, highly stable within individuals and robust to an experimental challenge (i.e. sleep deprivation) known to have considerable impact on the NREM sleep EEG. These findings indicate that the NREM sleep EEG represents a trait.

  12. The influence of affective empathy and autism spectrum traits on empathic accuracy

    NARCIS (Netherlands)

    Aan Het Rot, Marije; Hogenelst, Koen

    2014-01-01

    Autism spectrum disorder is characterized by interpersonal deficits and has been associated with limited cognitive empathy, which includes perspective taking, theory of mind, and empathic accuracy (EA). The capacity for affective empathy may also be impaired. In the present study we aimed to determi

  13. Trait and Ability Emotional Intelligence in Adolescents with and without Autism Spectrum Disorder

    Science.gov (United States)

    Boily, Roxanne; Kingston, Sydney E.; Montgomery, Janine M.

    2017-01-01

    Social-emotional impairments are considered core symptoms of Autism Spectrum Disorder (ASD). Although numerous interventions have been developed to remediate the social deficits in children with ASD, few have been designed to meet the needs of youth. Given research demonstrating relations between emotional intelligence (EI) and social outcomes in…

  14. The influence of affective empathy and autism spectrum traits on empathic accuracy

    NARCIS (Netherlands)

    Aan Het Rot, Marije; Hogenelst, Koen

    2014-01-01

    Autism spectrum disorder is characterized by interpersonal deficits and has been associated with limited cognitive empathy, which includes perspective taking, theory of mind, and empathic accuracy (EA). The capacity for affective empathy may also be impaired. In the present study we aimed to

  15. The influence of affective empathy and autism spectrum traits on empathic accuracy

    NARCIS (Netherlands)

    Aan Het Rot, Marije; Hogenelst, Koen

    2014-01-01

    Autism spectrum disorder is characterized by interpersonal deficits and has been associated with limited cognitive empathy, which includes perspective taking, theory of mind, and empathic accuracy (EA). The capacity for affective empathy may also be impaired. In the present study we aimed to determi

  16. Leaf-fracture properties correlated with nutritional traits in nine Australian seagrass species: implications for susceptibility to herbivory

    NARCIS (Netherlands)

    de los Santos, C.B.; Brun, F.G.; Onoda, Y.; Cambridge, M.L.; Bouma, T.J.; Vergara, J.J.; Pérez-Lloréns, J.L.

    2012-01-01

    Seagrasses are exposed to the constant risk of structural damage due to abiotic factors, such as waves and currents, and biotic factors, e. g. herbivory. Leaf mechanical resistance is therefore essential in protecting plants from structural failure and may also have ecological consequences. For exam

  17. Weak coordination among petiole, leaf, vein, and gas-exchange traits across 41 Australian angiosperm species and its possible implications

    Science.gov (United States)

    Background and Aims Close coordination between leaf gas exchange and maximal hydraulic supply has been reported across diverse plant life-forms. However, recent reports suggest that this relationship may become weak or break down completely within the angiosperms. Methods To examine this possi...

  18. Photosynthetic traits of five neotropical rainforest tree species: interactions between light response curves and leaf-to-air vapour pressure deficit

    Directory of Open Access Journals (Sweden)

    Marcelo Schramm Mielke

    2005-09-01

    Full Text Available Measurements of leaf gas exchange at different photosynthetic photon flux density (PPFD levels were conducted in order to compare the photosynthetic traits of five neotropical rainforest tree species, with a special emphasis on empirical mathematical models to estimate the light response curve parameters incorporating the effects of leaf-to-air vapour pressure deficit (D on the saturated photosynthetic rate (Amax. All empirical mathematical models seemed to provide a good estimation of the light response parameters. Comparisons of the leaf photosynthetic traits between different species needed to select an appropriate model and indicated the microenvironmental conditions when the data were collected. When the vapour pressure deficit inside the chamber was not controlled, the incorporation of linear or exponencial functions that explained the effects of D on leaf gas exchange, was a very good method to enhance the performance of the models.Medições das trocas gasosas foliares em diferentes níveis do densidade de fluxo de fótons fotossintéticamente ativos (PPFD foram realizadas com o objetivo de comparar as características fotossintéticas de cinco espécies arbóreas de florestas úmidas neotropicais, com especial ênfase em modelos matemáticos empíricos para estimativa de parâmetros derivados das curvas de resposta à radiação luminosa e dos efeitos da diferença de pressão de vapor entre a folha e o ar (D na taxa fotossintética em saturação luminosa (Amax. Os modelos analisados proporcionaram boas estimativas para os parâmetros derivados das curvas de resposta à radiação luminosa. Comparações entre as características fotossintéticas de diferentes espécies devem sempre considerar os modelos utilizados, seguidas de indicações pormenorizadas das condições microambientais no momento em que os dados foram coletados. Quando a diferença de pressão de vapor não for controlada artificialmente durante as medições, a

  19. Autistic traits in couple dyads as a predictor of anxiety spectrum symptoms.

    Science.gov (United States)

    Lau, Winnie Yu-Pow; Gau, Susan Shur-Fen; Chiu, Yen-Nan; Wu, Yu-Yu

    2014-11-01

    The link between parental autistic tendency and anxiety symptoms was studied in 491 Taiwanese couples raising biological children with autism spectrum disorders (ASDs). Parental autistic tendency as measured by Autism Spectrum Quotient (AQ) was associated with anxiety symptoms across all domains. Large effect sizes were found in social phobia and post traumatic stress disorders for both parents, and in general anxiety disorder and agoraphobia for mothers. These associations were irrespective of child's autistic tendency, spouse's AQ scores and the couples' compatibility in their autistic tendency. Perceived family support and parental education moderated the link but not child's autistic severity. Research and clinical implications regarding psychiatric vulnerability of parents of children with ASD were drawn and discussed.

  20. Identiifcation and Genetic Analysis of a Novel Rice Spotted-Leaf Mutant with Broad-Spectrum Resistance to Xanthomonas oryzae pv. oryzae

    Institute of Scientific and Technical Information of China (English)

    SHEN Hai-chao; SHI Yong-feng; FENG Bao-hua; WANG Hui-mei; XU Xia; HUANG Qi-na; LÜ Xiang-guang; WU Jian-li

    2014-01-01

    A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were signiifcantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was signiifcantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1 023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was ifnally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identiifed near the chromosomal region.

  1. Leaf functional traits of different forest communities in Ziwuling Mountains of Loess Plateau%黄土高原子午岭不同森林群落叶功能性状

    Institute of Scientific and Technical Information of China (English)

    李宏伟; 王孝安; 郭华; 王世雄; 夏菲

    2012-01-01

    对黄土高原子午岭地区5种主要森林群落中重要值>0.1的物种叶功能性状进行了比较,结果表明:1)叶干物质含量(LDMC)与比叶面积(SLA)呈负相关;SLA与叶厚度(LT)呈负相关,但与叶氮含量(LNC)和叶磷含量(LPC)呈正相关;LT与LNC、LPC和叶钾含量( LKC)呈负相关;LNC、LPC和LKC三者之间均呈正相关.2)坡位是影响叶大小(LS)、LT、LNC和LKC的主要地形因子,海拔对LPC和SLA的影响最大,而坡向则是影响LDMC的主要因子.因此,叶功能性状之间所呈现的特征及其对立地条件的适应都表现出了植物的生态策略.3)各群落间的乔木层叶功能性状均有显著差异,灌木层的叶功能性状无显著差异,而草本层除了LDMC无显著差异(P>0.05)外,其他叶功能性状均有显著差异,说明群落的叶功能性状的大小取决于群落内物种的叶功能性状及其重要值.%A comparative study was made on the leaf functional traits of the plant species whose importance value is >0. 1 in five main forest communities in Ziwuling Mountains of the Loess Plateau. For the test plant species, their leaf dry matter content ( LDMC) had significant nega-tive correlation with specific leaf area ( SLA) , SAL was significantly negatively correlated with leaf thickness ( LT) but positively correlated with leaf nitrogen content ( LNC) and leaf phosphor-us content (LPC) , LT was significantly negatively correlated with LNC, LPC, and leaf potassium content (LKC) , and there were significant positive correlations among LKC, LPC, and LNC. Slope position was the main terrain factor affecting leaf size, LT, and LNC, elevation had greater effects on LPC and SLA, while slope direction was the main factor affecting LDMC. The relation-ships among the leaf functional traits and the adaptation of the leaf functional traits to terrain fac-tors showed the ecological strategy of the plant species. The leaf functional traits of the plant spe-cies in tree layers of

  2. Effect of dietary supplement of sugar beet, neem leaf, linseed and coriander on growth performance and carcass trait of Vanaraja chicken

    Directory of Open Access Journals (Sweden)

    Punita Kumari

    2014-09-01

    Full Text Available Aim: This study was planned to investigate the effect of sugar beet, neem leaf, linseed and coriander on growth parameters such as feed intake, body weight gain, feed conversion ratio (FCR, performance index (PI, and carcass characteristics in broiler birds. Materials and Methods: The experiment was conducted for a period of 42 days on Vanaraja strain of broiler birds. Different dietary supplement such as sugar beet meal, neem leaf meal, linseed meal and coriander seed meal were used in the basal diet. All day-old 150 male chicks were individually weighed and distributed into five groups having 30 birds in each. Each group was further sub-divided into triplicates having 10 birds in each. Group T1served as control and rest groups T2, T3, T4 and T5 as treatment groups. Birds in T1 group were fed basal ration only, however, T2 , T3, T4 and T5 groups were fed basal ration mixed with 2.5% sugar beet meal, neem leaf meal, linseed meal, and coriander seed meal individually, respectively. Results: Broilers supplemented with herbs/spices showed improvement in growth attributes and carcass characteristics. Broilers fed with herbs at the rate of 2.5% had higher feed intake except sugar beet and coriander seed meal fed group. The body weight and weight gain was also significantly (p0.05 affected. Average giblet percentage of all supplemented groups were significantly (p<0.05 higher than control and was found to be highest in neem leaf meal fed group. Average by-product percentage was found to be highest in linseed fed group. Conclusion: Various herbs such as sugar beet, neem leaf, linseed and coriander seed meals affected the growth performance, and carcass trait showed positive inclination toward supplemented groups in broilers. The exact mode of action of these herbs/spices is still not clear, however, one or more numbers of active compounds present in these supplements may be responsible.

  3. Spectrum

    DEFF Research Database (Denmark)

    Høgfeldt Hansen, Leif

    2016-01-01

    The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum.......The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum....

  4. Does investment in leaf defenses drive changes in leaf economic strategy? A focus on whole-plant ontogeny.

    Science.gov (United States)

    Mason, Chase M; Donovan, Lisa A

    2015-04-01

    Leaf defenses have long been studied in the context of plant growth rate, resource availability, and optimal investment theory. Likewise, one of the central modern paradigms of plant ecophysiology, the leaf economics spectrum (LES), has been extensively studied in the context of these factors across ecological scales ranging from global species data sets to temporal shifts within individuals. Despite strong physiological links between LES strategy and leaf defenses in structure, function, and resource investment, the relationship between these trait classes has not been well explored. This study investigates the relationship between leaf defenses and LES strategy across whole-plant ontogeny in three diverse Helianthus species known to exhibit dramatic ontogenetic shifts in LES strategy, focusing primarily on physical and quantitative chemical defenses. Plants were grown under controlled environmental conditions and sampled for LES and defense traits at four ontogenetic stages. Defenses were found to shift strongly with ontogeny, and to correlate strongly with LES strategy. More advanced ontogenetic stages with more conservative LES strategy leaves had higher tannin activity and toughness in all species, and higher leaf dry matter content in two of three species. Modeling results in two species support the conclusion that changes in defenses drive changes in LES strategy through ontogeny, and in one species that changes in defenses and LES strategy are likely independently driven by ontogeny. Results of this study support the hypothesis that leaf-level allocation to defenses might be an important determinant of leaf economic traits, where high investment in defenses drives a conservative LES strategy.

  5. Change in hydraulic properties and leaf traits of a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Directory of Open Access Journals (Sweden)

    B. Schuldt

    2010-11-01

    Full Text Available In a throughfall displacement experiment on Sulawesi, Indonesia, three 0.16 ha stands of a premontane perhumid rainforest were exposed to a two-year soil desiccation period that reduced the soil moisture in the upper soil layers beyond the conventional wilting point. About 25 variables, including leaf morphological and chemical traits, stem diameter growth and hydraulic properties of the xylem in the trunk and terminal twigs, were investigated in trees of the tall-growing tree species Castanopsis acuminatissima (Fagaceae by comparing desiccated roof plots with nearby control plots. We tested the hypotheses that this tall and productive species is particularly sensitive to drought, and the exposed upper sun canopy is more affected than the shade canopy. Hydraulic conductivity in the xylem of terminal twigs normalised to vessel lumen area was reduced by 25%, leaf area-specific conductivity by 10–33% during the desiccation treatment. Surprisingly, the leaves present at the end of the drought treatment were significantly larger, but not smaller in the roof plots, though reduced in number (about 30% less leaves per unit of twig sapwood area, which points to a drought effect on the leaf bud formation while the remaining leaves may have profited from a surplus of water. Mean vessel diameter and axial conductivity in the outermost xylem of the trunk were significantly reduced and wood density increased, while annual stem diameter increment decreased by 26%. In contradiction to our hypotheses, (i we found no signs of major damage to the C. acuminatissima trees nor to any other drought sensitivity of tall trees, and (ii the exposed upper canopy was not more drought susceptible than the shade canopy.

  6. Neural Bases of Theory of Mind in Children with Autism Spectrum Disorders and Children with Conduct Problems and Callous-Unemotional Traits

    Science.gov (United States)

    O'Nions, Elizabeth; Sebastian, Catherine L.; McCrory, Eamon; Chantiluke, Kaylita; Happé, Francesca; Viding, Essi

    2014-01-01

    Individuals with autism spectrum disorders (ASD) have difficulty understanding other minds (Theory of Mind; ToM), with atypical processing evident at both behavioural and neural levels. Individuals with conduct problems and high levels of callous-unemotional (CU) traits (CP/HCU) exhibit reduced responsiveness to others' emotions and difficulties…

  7. Heterogeneity of subclinical autistic traits among parents of children with autism spectrum disorder: Identifying the broader autism phenotype with a data-driven method.

    Science.gov (United States)

    Bora, Emre; Aydın, Aydan; Saraç, Tuğba; Kadak, Muhammed Tayyib; Köse, Sezen

    2017-02-01

    Clinical diagnosis of autism spectrum disorder (ASD) can be conceptualized as the extreme end of the distribution of subclinical autistic traits related to genetic susceptibility factors (broad autism phenotype (BAP)) in the general population. Subclinical autistic traits are significantly more common among unaffected first-degree relatives of probands with autism. However, there is a significant heterogeneity of autistic traits in family members of individuals with ASD and severity of autistic traits are not significantly different from controls in the majority of these relatives. The current study investigated the heterogeneity of autistic traits using latent class analysis (LCA) of the Autism Spectrum Quotient (AQ) ratings of 673 parents of children with ASD and 147 parents of typically developing children. Two distinct subgroups, including a "low-scoring" and a "high-scorer (BAP)" groups, were found. In comparison to control parents, a significantly larger proportion (21.1% vs. 7.5%) of parents of ASD were members of BAP group. Communication subscale made a distinctive contribution to the separation of high and low-scoring groups (d = 2.77). Further studies investigating neurobiological and genetic biomarkers and stability of these two subgroups over time are important for understanding the nature of autistic traits in the general population. Autism Res 2017, 10: 321-326. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  8. LEAF TRAITS AND PLASTIC POTENTIAL OF PLANT SPECIES IN A LIGHT-EDAPHIC GRADIENT FROM RESTINGA IN SOUTHERN BRAZIL

    Directory of Open Access Journals (Sweden)

    João Carlos Ferreira Melo Júnior

    2015-11-01

    Full Text Available ABSTRACTRestinga formations grow on sandy spits of coastal plains, an environment whose conditions limit the growth and development of vegetal species. Studies on restinga gradients are good examples of how plants acclimate to restrictive environments. This work compares three woody species co-occurring in four vegetations of a restinga from Southern Brazil. It pinpoints morpho-anatomical attributes that favor the survival of species faced with spatial variability of soil and light conditions. Results indicate that they respond differently to environmental variables on different scales. The plastic response of morphological attributes is more marked than that of anatomical ones. Varronia curassavica and Dodonaea viscosa showed more xeromorphic features on the more stressful restinga formations while Symphyopappus casarettoi varied between xerophyte to mesophyte forms along the gradient. Individual height, fresh and dry leaf masses, leaf area, specific leaf mass and area, leaf density, and water content are particularly noteworthy. These responses are strategies allowing the studied species to survive in restinga environment with highly variable soil nutrient, water availability, and light conditions. The environmental conditions are important features that modulate de plant morphology along the gradient. Keywords: coastal vegetation, leaf morphology, leaf anatomy, light and soil conditions.RESUMENRestinga (o cordón litoral es una formación que se desarrolla en cordones arenosos de planícies litorales. Este ambiente presenta condiciones limitantes al crecimiento y desarrollo de las especies vegetales. Estudios en gradientes de restinga son buenos ejemplos de como las plantas se aclimatan a las condiciones ambientales restrictivas. Este trabajo tuvo como objetivo comparar tres especies leñosas co-ocurrentes en cuatro fisonomías de una restinga del sur de Brasil, buscando conocer los atributos morfo-anatómicos que favorecen la sobrevivencia

  9. Asperger syndrome and schizophrenia: Overlap of self-reported autistic traits using the Autism-spectrum Quotient (AQ).

    Science.gov (United States)

    Lugnegård, Tove; Hallerbäck, Maria Unenge; Gillberg, Christopher

    2015-05-01

    In clinical practice, the differential diagnosis of Asperger syndrome (AS) versus schizophrenia can be a challenge. Some self-report instruments-such as the Autism-spectrum Quotient (AQ)-have been portrayed as proxies for the diagnosis of AS. However, it has not been demonstrated to what extent autistic traits-as measured by the AQ-separate AS from schizophrenia. To examine the AS-schizophrenia discriminating ability of the AQ. The AQ is a 50-item self-administered questionnaire (with score range 0-50) for measuring "autistic traits" in adults. Here, it was completed by 136 individuals: 36 with schizophrenic psychosis, 51 with AS and 49 non-clinical comparison cases. A receiver operating characteristic (ROC) analysis for the total AQ score was performed to examine the discriminating power of the instrument. Both individuals with schizophrenia and individuals with AS scored significantly higher on AQ than the non-clinical group. The mean total AQ score (± standard deviation) of the AS group (26.7 ± 8.9; range 9-44) was significantly higher than that of the schizophrenia group (22.7 ± 6.2; range 10-35) (P = 0.041). However, when using the full Likert scale for scoring, the difference did not reach significance. In the ROC analysis of total AQ scores for AS versus schizophrenia, the area under the curve (AUC) was 0.65 (P = 0.02). Although mean AQ scores separated AS and schizophrenia at a group comparison level, significant overlap of AQ scores across the two diagnostic groups clearly reduces the discriminating power of the AQ in the separation of schizophrenia from AS.

  10. 沙地生境和平茬年限对沙柳叶功能特征的影响%Effects of sandy land water habitat and years after rejuvenation pruning on leaf functional traits of Salix psammophila

    Institute of Scientific and Technical Information of China (English)

    张萍萍; 李秧秧; 邵明安

    2011-01-01

    研究了毛乌素沙地南缘水滨边丘间地和干旱丘顶两种生境下沙柳平茬后不同年限(1、2、3~4和5~6年)对沙柳叶片光合气体交换、水分利用效率、结构特性及氮、磷养分含量等叶功能特征的影响.结果表明:水滨边丘间地沙柳叶片的净光合速率、气孔导度、瞬时和长期水分利用效率均高于丘顶,但N、P养分含量低于丘顶;两种生境下沙柳的叶结构性状无显著差异.干旱生境下沙柳主要通过增加养分含量、降低光合和水分利用来生存.随平茬年限增加,叶片净光合速率和气孔导度显著下降,氮含量和瞬时水分利用效率亦呈下降趋势,且二者之间呈显著正相关;平茬后1年的叶面积最高,比叶质量和叶干物质含量最低,此后比叶质量增加,叶面积和干物质含量不变;叶结构性状与光合及养分特性之间无显著相关性.叶光合活性和氮含量的下降是沙柳随平茬年限增加而衰败的重要原因.%This paper studied the effects of habitats (riparian inter-dune and dry top dune) and years after rejuvenation pruning (1, 2, 3-4, and 5-6 years) on the leaf functional traits (gas ex-change, water use efficiency, structural traits, and N and P contents) of Salix psammophila growing in the southern edge of Mu Us Sandy Land. In the habitat of riparian inter-dune, the leaf net photo-synthetic rate, stomatal conductance, and instantaneous and long-term water use efficiencies were all higher, while the leaf N and P contents were lower, as compared with those in the habitat of dry top dune. No significant differences were observed in the leaf structural traits between the two habi-tats , suggesting that S. psammophila could survive in a dry habitat by the strategies of increasing nutrient uptake and decreasing photosynthesis and water use. With the increasing years after rejuve-nation pruning, the leaf net photosynthetic rate and stomatal conductance decreased significantly

  11. Trait-level temporal lobe hypoactivation to social exclusion in unaffected siblings of children and adolescents with autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Danielle Z. Bolling

    2015-06-01

    Full Text Available Social exclusion elicits powerful feelings of negative affect associated with rejection. Additionally, experiencing social exclusion reliably recruits neural circuitry associated with emotion processing. Recent work has demonstrated abnormal neural responses to social exclusion in children and adolescents with autism spectrum disorders (ASD. However, it remains unknown to what extent these abnormalities are due to atypical social experiences versus genetic predispositions to atypical neural processing. To address this question, the current study investigated brain responses to social exclusion compared to a baseline condition of fair play in unaffected siblings of youth with ASD using functional magnetic resonance imaging. We identified common deviations between unaffected siblings and ASD probands that might represent trait-level abnormalities in processing Social Exclusion vs. Fair Play, specifically in the right anterior temporoparietal junction extending into posterior superior temporal sulcus. Thus, hypoactivation to Social Exclusion vs. Fair Play in this region may represent a shared genetic vulnerability to developing autism. In addition, we present evidence supporting the idea that one's status as an unaffected sibling moderates the relationship between IQ and neural activation to Social Exclusion vs. Fair Play in anterior cingulate cortex. These results are discussed in the context of previous literature on neural endophenotypes of autism.

  12. Trait-level temporal lobe hypoactivation to social exclusion in unaffected siblings of children and adolescents with autism spectrum disorders.

    Science.gov (United States)

    Bolling, Danielle Z; Pelphrey, Kevin A; Vander Wyk, Brent C

    2015-06-01

    Social exclusion elicits powerful feelings of negative affect associated with rejection. Additionally, experiencing social exclusion reliably recruits neural circuitry associated with emotion processing. Recent work has demonstrated abnormal neural responses to social exclusion in children and adolescents with autism spectrum disorders (ASD). However, it remains unknown to what extent these abnormalities are due to atypical social experiences versus genetic predispositions to atypical neural processing. To address this question, the current study investigated brain responses to social exclusion compared to a baseline condition of fair play in unaffected siblings of youth with ASD using functional magnetic resonance imaging. We identified common deviations between unaffected siblings and ASD probands that might represent trait-level abnormalities in processing Social Exclusion vs. Fair Play, specifically in the right anterior temporoparietal junction extending into posterior superior temporal sulcus. Thus, hypoactivation to Social Exclusion vs. Fair Play in this region may represent a shared genetic vulnerability to developing autism. In addition, we present evidence supporting the idea that one's status as an unaffected sibling moderates the relationship between IQ and neural activation to Social Exclusion vs. Fair Play in anterior cingulate cortex. These results are discussed in the context of previous literature on neural endophenotypes of autism.

  13. The Leaf Functional Traits and their Correlation Analysis of Three Seedlings of Magnoliaceae%3种木兰科植物幼苗叶片功能性状及关联性分析

    Institute of Scientific and Technical Information of China (English)

    李超; 赵广东; 史作民; 王兵; 邓宗富; 夏晨; 王财英; 陈和东

    2016-01-01

    研究了中亚热带木兰科乐昌含笑( Micheliachapensls)、深山含笑( Micheliamaudiae)和观光木( Tsoongioden-dronodorum)2年生幼苗在生长季节的叶厚度、比叶面积、叶干物质含量、叶氮浓度、叶磷浓度和叶氮磷比6种叶片性状的种间差异及其相关性。结果表明:(1)3树种的6个叶片性状表现出了一定的种间差异性,观光木比叶面积、叶干物质含量、叶氮磷比最大,叶氮浓度最高;乐昌含笑叶干物质含量最小,叶氮浓度、叶磷浓度最低;深山含笑叶磷浓度最高,比叶面积、叶氮磷比最小,但3树种叶片的叶厚度无显著性差异( P>0.1)。(2)3树种叶片的叶厚度与叶干物质含量极显著正相关( P<0.01),比叶面积与叶氮浓度显著正相关( P<0.05);叶干物质含量与叶磷浓度显著正相关( P<0.05);叶氮浓度与叶磷浓度极显著正相关( P<0.01)。(3)3树种叶片氮磷比均在9~12,且差异显著( P<0.05)。研究结果显示,3种木兰科树种幼苗叶片的6种功能性状表现出了一定的种间差异性,但同一功能性状的大小顺序和种间差异的显著性不同;同时所有树种幼苗叶片各功能性状间的相关性及其显著程度不同。%Interspecific differences in leaf thickness,specific leaf area,leaf dry matter content,leaf nitrogen concentration,leaf phosphorus concentration,ratio of leaf nitrogen and phosphorus concentration and their corre-lation of Micheliachapensls,Micheliamaudiae and Tsoongiodendronodorum two-year seedlings of Magnoliaceae in the mid-subtropical zone of China in the growing season were investigated.The results were as follows:(1) The six leaf trait indicators of the three trees exhibited a certain interspecific difference,among the three tree seedlings,the specific leaf area,leaf dry matter content and ratio of leaf nitrogen and phosphorus concentration of

  14. Cognitive and affective empathy in children with conduct problems: additive and interactive effects of callous-unemotional traits and autism spectrum disorders symptoms.

    Science.gov (United States)

    Pasalich, Dave S; Dadds, Mark R; Hawes, David J

    2014-11-30

    Callous-unemotional (CU) traits and autism spectrum disorders (ASD) symptoms are characterized by problems in empathy; however, these behavioral features are rarely examined together in children with conduct problems. This study investigated additive and interactive effects of CU traits and ASD symptoms in relation to cognitive and affective empathy in a non-ASD clinic-referred sample. Participants were 134 children aged 3 to 9 years (M=5.60; 79% boys) with oppositional defiant/conduct disorder, and their parents. Clinicians, teachers, and parents reported on dimensions of child behavior, and parental reports of family dysfunction and direct observations of parental warmth/responsiveness assessed quality of family relationships. Results from multiple regression analysis showed that, over and above the effects of child conduct problem severity and quality of family relationships, both ASD symptoms and CU traits were uniquely associated with deficits in cognitive empathy. Moreover, CU traits demonstrated an independent association with affective empathy, and this relationship was moderated by ASD symptoms. That is, there was a stronger negative association between CU traits and affective empathy at higher versus lower levels of ASD symptoms. These findings suggest including both CU traits and ASD-related social impairments in models delineating the atypical development of empathy in children with conduct problems.

  15. Towards a worldwide wood economics spectrum.

    Science.gov (United States)

    Chave, Jerome; Coomes, David; Jansen, Steven; Lewis, Simon L; Swenson, Nathan G; Zanne, Amy E

    2009-04-01

    Wood performs several essential functions in plants, including mechanically supporting aboveground tissue, storing water and other resources, and transporting sap. Woody tissues are likely to face physiological, structural and defensive trade-offs. How a plant optimizes among these competing functions can have major ecological implications, which have been under-appreciated by ecologists compared to the focus they have given to leaf function. To draw together our current understanding of wood function, we identify and collate data on the major wood functional traits, including the largest wood density database to date (8412 taxa), mechanical strength measures and anatomical features, as well as clade-specific features such as secondary chemistry. We then show how wood traits are related to one another, highlighting functional trade-offs, and to ecological and demographic plant features (growth form, growth rate, latitude, ecological setting). We suggest that, similar to the manifold that tree species leaf traits cluster around the 'leaf economics spectrum', a similar 'wood economics spectrum' may be defined. We then discuss the biogeography, evolution and biogeochemistry of the spectrum, and conclude by pointing out the major gaps in our current knowledge of wood functional traits.

  16. Species adaptive strategies and leaf economic relationships across serpentine and non-serpentine habitats on Lesbos, eastern Mediterranean.

    Directory of Open Access Journals (Sweden)

    George C Adamidis

    Full Text Available Shifts in species' traits across contrasting environments have the potential to influence ecosystem functioning. Plant communities on unusually harsh soils may have unique responses to environmental change, through the mediating role of functional plant traits. We conducted a field study comparing eight functional leaf traits of seventeen common species located on both serpentine and non-serpentine environments on Lesbos Island, in the eastern Mediterranean. We focused on species' adaptive strategies across the two contrasting environments and investigated the effect of trait variation on the robustness of core 'leaf economic' relationships across local environmental variability. Our results showed that the same species followed a conservative strategy on serpentine substrates and an exploitative strategy on non-serpentine ones, consistent with the leaf economic spectrum predictions. Although considerable species-specific trait variability emerged, the single-trait responses across contrasting environments were generally consistent. However, multivariate-trait responses were diverse. Finally, we found that the strength of relationships between core 'leaf economic' traits altered across local environmental variability. Our results highlight the divergent trait evolution on serpentine and non-serpentine communities and reinforce other findings presenting species-specific responses to environmental variation.

  17. Coordination of physiological and structural traits in Amazon forest trees

    Science.gov (United States)

    Patiño, S.; Fyllas, N. M.; Baker, T. R.; Paiva, R.; Quesada, C. A.; Santos, A. J. B.; Schwarz, M.; Ter Steege, H.; Phillips, O. L.; Lloyd, J.

    2012-02-01

    Many plant traits covary in a non-random manner reflecting interdependencies associated with "ecological strategy" dimensions. To understand how plants integrate their structural and physiological investments, data on leaf and leaflet size and the ratio of leaf area to sapwood area (ΦLS) obtained for 1020 individual trees (encompassing 661 species) located in 52 tropical forest plots across the Amazon Basin were incorporated into an analysis utilising existing data on species maximum height (Hmax), seed size, leaf mass per unit area (MA), foliar nutrients and δ13C, and branch xylem density (ρx). Utilising a common principal components approach allowing eigenvalues to vary between two soil fertility dependent species groups, five taxonomically controlled trait dimensions were identified. The first involves primarily cations, foliar carbon and MA and is associated with differences in foliar construction costs. The second relates to some components of the classic "leaf economic spectrum", but with increased individual leaf areas and a higher ΦLS newly identified components for tropical tree species. The third relates primarily to increasing Hmax and hence variations in light acquisition strategy involving greater MA, reductions in ΦLS and less negative δ13C. Although these first three dimensions were more important for species from high fertility sites the final two dimensions were more important for low fertility species and were associated with variations linked to reproductive and shade tolerance strategies. Environmental conditions influenced structural traits with ρx of individual species decreasing with increased soil fertility and higher temperatures. This soil fertility response appears to be synchronised with increases in foliar nutrient concentrations and reductions in foliar [C]. Leaf and leaflet area and ΦLS were less responsive to the environment than ρx. Thus, although genetically determined foliar traits such as those associated with leaf

  18. 中梁山石灰岩山地30种主要植物叶片性状研究%Leaf Traits of Main Plants on Limestone Area in Zhongliang Mountain

    Institute of Scientific and Technical Information of China (English)

    刘宏伟; 王微; 左娟; 陶建平

    2014-01-01

    为探讨生长在喀斯特石灰岩山地植物叶片性状适应特征,在重庆中梁山海石公园选取乔、灌、草三种生活型植物共30种,分别测定其叶干质量(mLDMC )、比叶面积(SLA)、叶pH、叶碳质量(mLCC )、叶氮质量(mLNC )和叶碳氮比等六个叶片性状因子.结果表明:不同叶片性状因子变异系数不同,其中,植物 mLDMC 、SLA和mLNC变异较大,分别为28.7%,50.8%和21.4%;mLDMC和 SLA在不同生活型植物中存在显著差异,与乔木和灌木相比,草本具有较低的mLDMC和较大的 SLA ,而乔木和灌木在两者之间差异不显著;所有叶片性状因子中,植物mLDMC和 SLA呈显著负相关,其他因子间没有显著相关性.可见,mLDMC和 SLA是植物资源利用分类轴上划分植物类群的最佳指标,石灰岩地区不同生活型植物叶片性状不同,这是植物和环境相互选择综合作用的结果.%To explore the adaptive feature of plant leaf traits in Karst limestone area ,30 species of three life forms ,namely ,trees ,shrubs and herbs from Zhongling mountain in Chongqing city of Southwest China have been selected and their leaf dry matter content (mLDMC ) ,specific leaf area(SLA) ,leaf pH ,leaf carbon concentration(mLCC ) ,leaf nitrogen concentration (mLNC ) and leaf carbon nitrogen ratio (C/N) measured . The results show that the coefficient of variation differed between different leaf traits and a large variation has been observed in mLDMC and SLA being 28 .7% ,0 .8% ,1 .4% ,respectively .mLDMC and SLA differed significantly among three life forms .Compared with trees and shrubs ,herbs have lower mLDMC and higher SLA ,but no significant difference is observed between trees and shrubs .mLDMC and SLA are significantly negatively correlated of all leaf traits .However ,there is no significant correlation among other leaf traits . It is concluded that mLDMC and SL A could be used to predict the plant

  19. Different brain responses during empathy in autism spectrum disorders versus conduct disorder and callous-unemotional traits.

    Science.gov (United States)

    Klapwijk, Eduard T; Aghajani, Moji; Colins, Olivier F; Marijnissen, Godfried M; Popma, Arne; van Lang, Natasja D J; van der Wee, Nic J A; Vermeiren, Robert R J M

    2016-06-01

    Deficits in empathy are reported in autism spectrum disorders (ASD) and also underlie antisocial behavior of individuals with conduct disorder and callous-unemotional traits (CD/CU+). Many studies suggest that individuals with ASD are typically impaired in cognitive aspects of empathy, and individuals with CD/CU+ typically in affective aspects. In the current study, we compared the neural correlates of cognitive and affective aspects of empathy between youth with ASD and youth with CD/CU+. Functional magnetic resonance imaging (fMRI) was used to assess boys with ASD (N = 23), boys with CD/CU+ (N = 23), and typically developing (TD) boys (N = 33), aged 15-19 years. Angry and fearful faces were presented and participants were asked to either infer the emotional state from the face (other-task; emotion recognition) or to judge their own emotional response to the face (self-task; emotional resonance). During emotion recognition, boys with ASD showed reduced responses compared to the other groups in the ventromedial prefrontal cortex (vmPFC). During emotional resonance, the CD/CU+ and ASD groups showed reduced amygdala responses compared to the TD controls, boys with ASD showed reduced responses in bilateral hippocampus, and the CD/CU+ boys showed reduced responses in the inferior frontal gyrus (IFG) and anterior insula (AI). Results suggest differential abnormal brain responses associated with specific aspects of empathic functioning in ASD and CD/CU+. Decreased amygdala responses in ASD and CD/CU+ might point to impaired emotion processing in both disorders, whereas reduced vmPFC responses suggest problems in processing cognitive aspects of empathy in ASD. Reduced IFG/AI responses, finally, suggest decreased emotional resonance in CD/CU+. © 2015 Association for Child and Adolescent Mental Health.

  20. Effects of elevated CO{sub 2} and temperature on photosynthesis and leaf traits of an understory dwarf bamboo in subalpine forest zone, China

    Energy Technology Data Exchange (ETDEWEB)

    Yongping Li; Yuanbin Zhang; Xiaolu Zhang; Chunyang Li [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Korpelainenc, H. [Univ. of Helsinki. Dept. of Agricultural Sciences, Helsinki (Finland); Berningerd, F. [Univ. of Helsinki. Dept. of Forest Sciences, Helsinki (Finland)

    2013-06-01

    The dwarf bamboo (Fargesia rufa Yi), growing understory in subalpine dark coniferous forest, is one of the main foods for giant panda, and it influences the regeneration of subalpine coniferous forests in southwestern China. To investigate the effects of elevated CO{sub 2}, temperature and their combination, the dwarf bamboo plantlets were exposed to two CO{sub 2} regimes (ambient and double ambient CO{sub 2} concentration) and two temperatures (ambient and +2.2 deg. C) in growth chambers. Gas exchange, leaf traits and carbohydrates concentration were measured after the 150-day experiment. Elevated CO{sub 2} significantly increased the net photosynthetic rate (A{sub net}), intrinsic water-use efficiency (WUE{sub i}) and carbon isotope composition ({delta}{sup 13}C) and decreased stomatal conductance (g{sub s}) and total chlorophyll concentration based on mass (Chl{sub m}) and area (Chl{sub a}). On the other hand, elevated CO{sub 2} decreased specific leaf area (SLA), which was increased by elevated temperature. Elevated CO{sub 2} also increased foliar carbon concentration based on mass (C{sub m}) and area (C{sub a}), nitrogen concentration based on area (N{sub a}), carbohydrates concentration (i.e. sucrose, sugar, starch and non-structural carbohydrates) and the slope of the A{sub net}-N{sub a} relationship. However, elevated temperature decreased C{sub m}, C{sub a} and N{sub a}. The combination of elevated CO{sub 2} and temperature hardly affected SLA, C{sub m}, C{sub a}, N{sub m}, N{sub a}, Chl{sub m} and Chl{sub a}. Variables A{sub net} and N{sub a} had positive linear relationships in all treatments. Our results showed that photosynthetic acclimation did not occur in dwarf bamboo at elevated CO{sub 2} and it could adjust physiology and morphology to enable the capture of more light, to increase WUE and improve nutritional conditions. (Author)

  1. Sheldon Spectrum and the Plankton Paradox: Two Sides of the Same Coin. A trait-based plankton size-spectrum model

    CERN Document Server

    Cuesta, José A; Law, Richard

    2016-01-01

    The Sheldon spectrum describes a remarkable regularity in aquatic ecosystems: the biomass density as a function of logarithmic body mass is approximately constant over many orders of magnitude. While size-spectrum models have explained this phenomenon for assemblages of multicellular organisms, this paper introduces a species-resolved size-spectrum model to explain the phenomenon in unicellular plankton. A Sheldon spectrum spanning the cell-size range of unicellular plankton necessarily consists of a large number of coexisting species covering a wide range of characteristic sizes. The coexistence of many phytoplankton species feeding on a small number of resources is known as the Paradox of the Plankton. Our model resolves the paradox by showing that coexistence is facilitated by the allometric scaling of four physiological rates. Two of the allometries have empirical support, the remaining two emerge from predator-prey interactions exactly when the abundances follow a Sheldon spectrum. Our plankton model is ...

  2. 3种阔叶幼苗叶片形态特征的季节变化%Seasonal Change of Leaf Trait of Three Broadleaf Seedlings

    Institute of Scientific and Technical Information of China (English)

    彭耀强; 薛立; 潘澜; 刘斌; 许鹏波

    2011-01-01

    为了了解叶形态变化的规律,为苗木培育提供理论依据,笔者通过测定黎蒴、火力楠、枫香3种幼苗叶片的长度、宽度、叶面积和叶干重的方法,对这3种幼苗叶长和叶宽的相关性、叶面积与干重的相关性、比叶重的季节变化进行研究.结果表明:叶长和叶宽呈极显著正相关,黎蒴和枫香的叶长与叶宽相关性随季节变化,而火力楠的规律性不强.新叶和老叶的面积与干重极显著相关.新叶的比叶重上半年变化较大,下半年变化平缓,一般2-4月出现最低值;上半年新叶的比叶重比老叶低,下半年两者相近.3种阔叶幼苗叶片的相似性和比叶重随季节发生变化,幼苗叶片干物质的积累随叶面积的扩大而增加,叶片千重与叶面积的相关性与树种和叶龄有关.%The methods of determining leaf length, leaf width, leaf area and leaf dry weight were used in seedlings of Castanopsis fissa, Michelia macclurei and Liquidambar formosana in order to understand change of their leaf shape and supply a theory basis for these seedlings culture, the correlations between leaf length and leaf width as well as between leaf area and leaf dry weight, and seasonal change of specific leaf weight (SLW) were studied in the three seedlings.The very significant correlation existed between leaf length and leaf width of the three seedlings.The month change of correlative coefficients of C.fissa and L.formosana seedlings was intimate with seasonal change, whereas that of M.macclurei seedlings was not regular.There were significant positive correlations between leaf area of young leaves and their leaf dry weight as well as between leaf area of old leaves and their leaf dry weight.The correlation between leaf dry weight and leaf area was correlative.The SLW change was great in the first half year and small in the second half year for young leaves.The SLW of young leaves was generally smaller than old leaves in the first half year

  3. The times they are a-changin': seasonal variations of leaf spectra in relation with leaf biochemical and biophysical properties

    Science.gov (United States)

    Yang, X.; Tang, J.; Mustard, J. F.

    2013-12-01

    Leaf traits such as chlorophyll concentration, leaf mass per area (LMA), and mesophyll cell area exposed to the internal area space per leaf area (Ames/A) are key biochemical or biophysical properties to understand the vegetation functioning. Measurements of leaf spectra provided a non-destructive way to estimate those parameters. Many studies have linked leaf spectra with some of leaf traits successfully, but the understanding of spectra-traits relationship is still limited in the following aspects: (1) how does the ability of spectra to estimate leaf traits change (or not) throughout the growing season? (2) How to quantify leaf internal structure with leaf spectra? (3) What are the leaf traits that contribute to the structure parameter in leaf reflectance model such as PROSPECT? To answer the questions above, we conducted weekly measurements of leaf spectra, leaf biochemical properties (chlorophyll, carotenoids, water, and total carbon and nitrogen) and biophysical properties (LMA and internal structures) during the growing seasons of year 2011 and 2012. We found that leaf traits express themselves in the leaf spectra at different wavelengths; the relationships between spectra and leaf traits vary throughout the season. Leaf internal structure parameters are mostly related to the near-infrared reflectance. The structure parameter (N) in PROSPECT is related to the Ames/A, LMA, and water content. Our results have broad implications for using hyperspectral imagers/sensors to monitor vegetations that have clear seasonal patterns.

  4. Decoupled leaf and stem economics in rain forest trees.

    Science.gov (United States)

    Baraloto, Christopher; Timothy Paine, C E; Poorter, Lourens; Beauchene, Jacques; Bonal, Damien; Domenach, Anne-Marie; Hérault, Bruno; Patiño, Sandra; Roggy, Jean-Christophe; Chave, Jerome

    2010-11-01

    Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by integrating data on functional traits for 13 448 leaves and wood tissues from 4672 trees representing 668 species of Neotropical trees. Strong correlations amongst traits previously defined as the leaf economics spectrum reflect a tradeoff between investments in productive leaves with rapid turnover vs. costly physical leaf structure with a long revenue stream. A second axis of variation, the 'stem economics spectrum', defines a similar tradeoff at the stem level: dense wood vs. high wood water content and thick bark. Most importantly, these two axes are orthogonal, suggesting that tradeoffs operate independently at the leaf and at the stem levels. By simplifying the multivariate ecological strategies of tropical trees into positions along these two spectra, our results provide a basis to improve global vegetation models predicting responses of tropical forests to global change.

  5. Physiological responses to social and nonsocial stimuli in neurotypical adults with high and low levels of autistic traits: implications for understanding nonsocial drive in autism spectrum disorders.

    Science.gov (United States)

    Singleton, Clarence J; Ashwin, Chris; Brosnan, Mark

    2014-12-01

    Researchers have suggested that the two primary cognitive features of autism spectrum disorder (ASD), a drive toward nonsocial processing and a reduced drive toward social processing, may be unrelated to each other in the neurotypical (NT) population and may therefore require separate explanations. Drive toward types of processing may be related to physiological arousal to categories of stimuli, such as social (e.g., faces) or nonsocial (e.g., trains). This study investigated how autistic traits in an NT population might relate to differences in physiological responses to nonsocial compared with social stimuli. NT participants were recruited to examine these differences in those with high vs. low degrees of ASD traits. Forty-six participants (21 male, 25 female) completed the Autism Spectrum Quotient (AQ) to measure ASD traits before viewing a series of 24 images while skin conductance response (SCR) was recorded. Images included six nonsocial, six social, six face-like cartoons, and six nonsocial (relating to participants' personal interests). Analysis revealed that those with a higher AQ had significantly greater SCR arousal to nonsocial stimuli than those with a low AQ, and the higher the AQ, the greater the difference between SCR arousal to nonsocial and social stimuli. This is the first study to identify the relationship between AQ and physiological response to nonsocial stimuli, and a relationship between physiological response to both social and nonsocial stimuli, suggesting that physiological response may underlie the atypical drive toward nonsocial processing seen in ASD, and that at the physiological level at least the social and nonsocial in ASD may be related to one another.

  6. Leaf traits and gas exchange in saplings of native tree species in the Central Amazon Características foliares e trocas gasosas em arvoretas de espécies nativas da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Keila Rego Mendes

    2010-12-01

    Full Text Available Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA, leaf thickness (LT, and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season and August (dry season of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax and stomatal conductance (g s, and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]. Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot and leaf anatomy (leaf thickness.Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA, espessura da folha (LT e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos

  7. The fungal symbiont of Acromyrmex leaf-cutting ants expresses the full spectrum of genes to degrade cellulose and other plant cell wall polysaccharides.

    Science.gov (United States)

    Grell, Morten N; Linde, Tore; Nygaard, Sanne; Nielsen, Kåre L; Boomsma, Jacobus J; Lange, Lene

    2013-12-28

    The fungus gardens of leaf-cutting ants are natural biomass conversion systems that turn fresh plant forage into fungal biomass to feed the farming ants. However, the decomposition potential of the symbiont Leucocoprinus gongylophorus for processing polysaccharides has remained controversial. We therefore used quantifiable DeepSAGE technology to obtain mRNA expression patterns of genes coding for secreted enzymes from top, middle, and bottom sections of a laboratory fungus-garden of Acromyrmex echinatior leaf-cutting ants. A broad spectrum of biomass-conversion-relevant enzyme genes was found to be expressed in situ: cellulases (GH3, GH5, GH6, GH7, AA9 [formerly GH61]), hemicellulases (GH5, GH10, CE1, GH12, GH74), pectinolytic enzymes (CE8, GH28, GH43, PL1, PL3, PL4), glucoamylase (GH15), α-galactosidase (GH27), and various cutinases, esterases, and lipases. In general, expression of these genes reached maximal values in the bottom section of the garden, particularly for an AA9 lytic polysaccharide monooxygenase and for a GH5 (endocellulase), a GH7 (reducing end-acting cellobiohydrolase), and a GH10 (xylanase), all containing a carbohydrate binding module that specifically binds cellulose (CBM1). Although we did not directly quantify enzyme abundance, the profile of expressed cellulase genes indicates that both hydrolytic and oxidative degradation is taking place. The fungal symbiont of Acromyrmex leaf-cutting ants can degrade a large range of plant polymers, but the conversion of cellulose, hemicellulose, and part of the pectin occurs primarily towards the end of the decomposition process, i.e. in the bottom section of the fungus garden. These conversions are likely to provide nutrients for the fungus itself rather than for the ants, whose colony growth and reproductive success are limited by proteins obtained from ingesting fungal gongylidia. These specialized hyphal tips are hardly produced in the bottom section of fungus gardens, consistent with the ants

  8. Effects of grazing disturbance on leaf traits and their interrelationships of plants in desert steppe%放牧干扰对荒漠草原植物叶性状及其相互关系的影响

    Institute of Scientific and Technical Information of China (English)

    安慧

    2012-01-01

    This paper studied the effects of grazing disturbance on the specific leaf area (SLA), leaf dry matter content (LDMC), leaf area, and leaf dry mass of dominant plant species Cynan-chum komarovii, Euphorbia esula, Glycyrrhiza uralensis, and Lespedeza potaninii in desert steppe of Ningxia, Northwest China, aimed to approach the responses and adaptation strategies of different plant species in desert steppe to the environmental change. With the decrease of grazing intensity, the specific leaf area (SLA) of the four dominant species presented a decreasing trend. Under different grazing intensities, the SLA of the four dominant species had significant differences, while the LDMC didn' t. There existed definite differences in the interrelationships of leaf traits among different plant species. For C. komarovii and G. uralensis, there was a significant negative relationship between SLA and LDMC, for E. esula and L. potaninii, there was a positive relationship between the two parameters. The changes in the leaf traits in response to grazing intensity suggested that the SLA could be more sensitive to the environmental change than LDMC, and the SLA could be used as an indicator of resources use strategies of plants in desert steppe environments.%以宁夏退化荒漠草原优势植物牛心朴子、乳浆大戟、甘草和牛枝子为对象,分析放牧干扰对植物的比叶面积(specific leaf area,SLA)、叶干物质含量(leaf dry matter content,LDMC)、叶面积和叶干质量等叶性状的影响,探讨荒漠草原生态系统中不同物种对环境改变的响应和适应对策.结果表明:随着放牧强度的降低,牛心朴子、乳浆大戟、甘草和牛枝子的SLA总体呈显著降低的趋势;SLA在不同放牧强度间差异显著,而LDMC则无显著差异.不同植物的叶性状相关性存在差异,牛心朴子和甘草的SLA和LDMC呈显著负相关,而乳浆大戟和牛枝子的SLA和LDMC呈正相关.牛心朴子、甘草、乳浆大戟和牛枝子

  9. 祁连山北坡霸王枝-叶性状关系的个体大小差异%Plant size differences with twig and leaf traits ofZygophyllum xanthoxylumin the northern slope of Qilian Mountains, China

    Institute of Scientific and Technical Information of China (English)

    杜晶; 赵成章; 宋清华; 史元春; 王继伟; 陈静

    2016-01-01

    枝与叶片权衡关系的个体大小差异性,是物种形成不同冠层结构充分利用空间资源的一种策略,有利于植株通过构型调整自身的光合效率和增强竞争力。在祁连山北坡荒漠草地,根据体积将霸王(Zygophyllum xanthoxylum)分为3个大小等级(I级:(植株体积的立方根(d)≤60 cm)、II级(60 cm 120 cm)),采用标准化主轴估计方法,研究了不同大小等级霸王种群枝长度与叶面积、叶数量的生长关系。结果表明:随着植株大小等级增大,霸王的枝长度、叶面积、枝横截面积逐渐增大,叶数量呈逐渐减小趋势;霸王枝长度的增长速度大于或等于叶面积的增长速度,枝长度的增加速度大于叶数量的增加速度;随着个体大小等级的增加,霸王枝长度与叶面积的异速斜率、枝长度与叶数量回归方程的y轴截距均显著减小,即植株叶面积与枝长度比值、叶数量的投入均显著降低。为提高资源利用效率,霸王小个体植株倾向于短枝上着生大量的小叶,大个体植株趋向于长枝上着生少量的大叶,随植株大小等级增加,叶面积增加而叶数量降低,对小枝的资源配置具有一定的影响。%Aims Understanding the effects of plant size on the trade-off between twigs and leaves is important for revealing strategies of plants forming different canopy structure, making full use of space resources, and enhancing their photosynthetic efficiency and competitiveness with adjusting plant configuration. Our objective was to study how twig and leaf traits ofZygophyllum xanthoxylum depended on size in the northern slope of Qilian Mountains, China. MethodsThe study was conducted in a desert grassland on the northern slope of the Qilian Mountains, Gansu Province, China. A transect was laid out horizontally along latitudinal direction, and three sample plots were set up along the transect at the interval of 50 m. Community traits

  10. Autistic Traits, ADHD Symptoms, Neurological Soft Signs and Regional Cerebral Blood Flow in Adults with Autism Spectrum Disorders

    Science.gov (United States)

    Manouilenko, Irina; Pagani, Marco; Stone-Elander, Sharon; Odh, Richard; Brolin, Fredrik; Hatherly, Robert; Jacobsson, Hans; Larsson, Stig A.; Bejerot, Susanne

    2013-01-01

    The resting regional cerebral blood flow (rCBF) patterns related to co-occurring symptoms such as inattention, hyperactivity, neurological soft signs and motor problems have not yet been disclosed in autism spectrum disorders (ASD). In this study thirteen adults with ASD and ten matched neurotypical controls underwent PET. The scores of rating…

  11. 广西多穗柯叶片性状变异及幼苗生长量研究%Variation of leaf traits and seedling growth of Lithocarpus polystachyus in Guangxi

    Institute of Scientific and Technical Information of China (English)

    曾祥艳; 陈金艳; 廖健明; 李建林; 马锦林

    2015-01-01

    plant resources in Guangxi.To provide certain reference for early selecting the superior germplasm,seeds from such four origins as Bama,Napo,Debao and Tianlin County were col-lected and sowed through ascertain difference of leaf morphology index and growth index in seedling plants between different origins of L .polystachyus in Guangxi,for nursing seedlings respectively,and tracking to survey and deter-mine the leaf traits and growth of seedlings aged one,and then compared the degree of variation of leaf area,leaf length,leaf width,leaf thickness,vein spacing,leaf fresh weight,leaf dry matter content,specific leaf area,leaf tissue density,the relative contents of chlorophyll,leaf water retention,plant height,ground diameter,dry weight per plant,taproot length,root dry weight per plant,leaf dry weight per plant between different origins of plants,and further to analyze the correlation between leaf traits and growth of seedling.The results were as follows:(1)There were a lot of differences in leaf traits and seedling growth among different origins,in which the length,width,LAI (leaf-area-index),veins distance,fresh weight,dry weight,tissue density of leaves and mean height,diameter, whole dry weight,root length,root dry weight of individual seedling from Bama were significantly higher than those from Napo,Debao and Tianlin.Mean biomass of individual seedling from Bama was one to two times as much as those from other three origins.Analysis from leaf water holding ability and net growth rate showed that the drought tolerance of seedlings from Bama were higher than those from three other origins.In conclusion,Bama could be con-sidered as a superior provenance on a preliminary basis;(2)The growth peak of L .polystachyus was in August in Guangxi,the plant height and the ground diameter growed significantly at this time.In order to obtain the largest ac-cumulation of seedling growth,some proposal that strengthen the water management,adjust the suitable conditions of field water

  12. Characteristics and Relationships of Foliar Water and Leaf Functional Traits of Desert Plants%荒漠植物叶片水分和功能性状特征及其相互关系

    Institute of Scientific and Technical Information of China (English)

    李善家; 苏培玺; 张海娜; 周紫鹃; 解婷婷

    2013-01-01

    Selected 14 dominant desert plant species in the middle reaches of Heihe River Basin, and 8 foliar water and leaf functional traits including stable carbon isotope composition (δ13C), total water content (TWO), relative water content (RWC), dry weight water content (DWWC), leaf dry matter content (LDMC), leaf water potential (LWP), specific leaf area (SLA) and specific leaf volume (SLV) were measured, studying on the characteristics and relationships of leaf functional traits of desert plants, and finding typical and crucial leaf functional traits which reflect plant adaptations to the harsh environment. The present results showed that foliar δ13C values of C4 plants ranged from -18%~15‰, including Salsola passerina, Haloxylon ammodendron and Calligo-num mongolicum, and foliar δ13C values of the other C3 plants ranged from -29‰~24‰. Among them, δ13C values of Hedysarum scoparium and Reaumuria soongorica exhibited the minimum and maximum values of -28.34‰and -24.63‰, respectively. The relationship between the traits obtained from C3 plants revealed that SLV was significantly negatively correlated with LDMC (P<0.0l), and positively correlated with TWC and DWWC (P<0.01). SLA was negatively correlated with LDMC (P=0.02), and δ13C was negatively correlated with LWP (P<0.01). SLV may serve as a key index of the characteristics of leaf traits of desert plants. Both the characteristics of leaf water content and functional traits and the responses to habitats demonstrate ecological strategies and adaptive ways of desert plants.%选取黑河流域中游荒漠区14种优势植物,测定了8个叶片水分与功能性状指标:稳定碳同位素组成(δ13C)、总含水量(TWC)、相对含水量(RWC)、干重含水量(DWWC)、叶干物质含量(LDMC)、叶片水势(LWP)、比叶面积(SLA)、比叶体积(SLV),探讨荒漠植物叶片水分与功能性状的特征以及相互之间的内在联系,探寻反映荒漠植物适应严酷环境的典型

  13. Testing functional trait-based mechanisms underpinning plant responses to grazing and linkages to ecosystem functioning in grasslands

    Directory of Open Access Journals (Sweden)

    S. X. Zheng

    2014-09-01

    Full Text Available Abundant evidence has shown that grazing alters plant functional traits, ecological strategies, community structure, and ecosystem functioning of grasslands. Few studies, however, have examined how plant responses to grazing are mediated by resource availability and functional group identity. We test functional trait-based mechanisms underlying the responses of different life forms to grazing and linkages to ecosystem functioning along a soil moisture gradient in the Inner Mongolia grassland. A principal component analysis (PCA based on 9 traits × 276 species matrix showed that the plant size spectrum (i.e., individual biomass, leaf economics spectrum (leaf N content and leaf density, and light competition spectrum (height and stem-leaf biomass ratio distinguished plant species responses to grazing. The three life forms exhibited differential strategies as indicated by trait responses to grazing. The annuals and biennials adopted grazing-tolerant strategies associated with high growth rate, reflected by high leaf N content and specific leaf area. The perennial grasses exhibited grazing-tolerant strategies associated with great regrowth capacity and high palatability scores, whereas perennial forbs showed grazing-avoidant strategies with short stature and low palatability scores. In addition, the dominant perennial bunchgrasses exhibited mixed tolerance–resistance strategies to grazing and mixed acquisitive–conservative strategies in resource utilization. Grazing increased the relative abundance of perennial forbs with low palatability in the wet and fertile meadow, but it promoted perennial grasses with high palatability in the dry and infertile typical steppe. Our findings suggest that the effects of grazing on plant functional traits are dependent on both the abiotic (e.g., soil moisture and biotic (e.g., plant functional group identity and composition factors. Grazing-induced shifts in functional group composition are largely dependent

  14. Testing functional trait-based mechanisms underpinning plant responses to grazing and linkages to ecosystem functioning in grasslands

    Science.gov (United States)

    Zheng, S. X.; Li, W. H.; Lan, Z. C.; Ren, H. Y.; Wang, K. B.; Bai, Y. F.

    2014-09-01

    Abundant evidence has shown that grazing alters plant functional traits, ecological strategies, community structure, and ecosystem functioning of grasslands. Few studies, however, have examined how plant responses to grazing are mediated by resource availability and functional group identity. We test functional trait-based mechanisms underlying the responses of different life forms to grazing and linkages to ecosystem functioning along a soil moisture gradient in the Inner Mongolia grassland. A principal component analysis (PCA) based on 9 traits × 276 species matrix showed that the plant size spectrum (i.e., individual biomass), leaf economics spectrum (leaf N content and leaf density), and light competition spectrum (height and stem-leaf biomass ratio) distinguished plant species responses to grazing. The three life forms exhibited differential strategies as indicated by trait responses to grazing. The annuals and biennials adopted grazing-tolerant strategies associated with high growth rate, reflected by high leaf N content and specific leaf area. The perennial grasses exhibited grazing-tolerant strategies associated with great regrowth capacity and high palatability scores, whereas perennial forbs showed grazing-avoidant strategies with short stature and low palatability scores. In addition, the dominant perennial bunchgrasses exhibited mixed tolerance-resistance strategies to grazing and mixed acquisitive-conservative strategies in resource utilization. Grazing increased the relative abundance of perennial forbs with low palatability in the wet and fertile meadow, but it promoted perennial grasses with high palatability in the dry and infertile typical steppe. Our findings suggest that the effects of grazing on plant functional traits are dependent on both the abiotic (e.g., soil moisture) and biotic (e.g., plant functional group identity and composition) factors. Grazing-induced shifts in functional group composition are largely dependent on resource

  15. Measuring feeding traits of a range of litter-consuming terrestrial snails : Leaf litter consumption, faeces production and scaling with body size

    NARCIS (Netherlands)

    Astor, Tina; Lenoir, Lisette; Berg, Matty P.

    2015-01-01

    Plant litter decomposition is an essential ecosystem function that contributes to energy and nutrient cycling above- and belowground. Terrestrial gastropods can affect this process in various ways: they consume and fragment leaf litter and create suitable habitats for microorganisms through the prod

  16. 西藏紫花针茅叶功能性状沿降水梯度的变化%Variations in leaf functional traits of Stipa purpurea along a rainfall gradient in Xizang, China

    Institute of Scientific and Technical Information of China (English)

    胡梦瑶; 张林; 罗天祥; 沈维

    2012-01-01

    Aims Stipa purpurea is the dominant species in alpine arid and semi-arid grasslands on the Tibetan Plateau. Our objectives are to determine if this species exhibits a strategy shift in its specific leaf area (SLA) to nitrogen (N) concentration relationship along a rainfall gradient and to detect possible effects of environmental factors on related leaf traits.Methods We investigated variations in leaf traits of S. Purpurea associated with climatic and soil factors along an east-west transect with a rainfall gradient (69-479 mm) but similar altitudes (4 300-4 700 m). Five locations from east to west are Damxung, Namco, Gerze, Mount Qomolangma and Rutog. We measured SLA, mass- and area-based leaf N concentration (Nmass, Narea), leaf density and thickness and soil total N along the transect. Important findings In pooled data, SLA and Nmass varied little with the growing season mean temperature and precipitation and the soil total N concentration. The SLA-Nmass relationship in S. Purpurea did not shift between the semi-humid areas (ratio of rainfall to evaporation > 0.11) and the arid and semi-arid areas (ratio < 0.11), although there was a positive correlation between SLA and Nmass across the five locations. Variation in SLA was mainly determined by leaf density in the semi-humid areas and by leaf thickness in the arid and semi-arid areas; both were negatively correlated with SLA. With increasing temperature or declining precipitation, leaf density decreased and leaf thickness increased, leading to non-significant relationships between SLA and climatic factors. The increase of leaf density in the semi-humid areas was correlated with the increase of Narea, but the increase of leaf thickness in the arid and semi-arid areas did not lead to change of Narea, resulting in unchanged Narea along the rainfall gradient. A positive correlation was detected between aboveground biomass and Narea in S. Purpurea, indicating that increased Narea may increase plant productivity. Our

  17. Fungal Root Microbiome from Healthy and Brittle Leaf Diseased Date Palm Trees (Phoenix dactylifera L.) Reveals a Hidden Untapped Arsenal of Antibacterial and Broad Spectrum Antifungal Secondary Metabolites.

    Science.gov (United States)

    Mefteh, Fedia B; Daoud, Amal; Chenari Bouket, Ali; Alenezi, Faizah N; Luptakova, Lenka; Rateb, Mostafa E; Kadri, Adel; Gharsallah, Neji; Belbahri, Lassaad

    2017-01-01

    In this study, we aimed to explore and compare the composition, metabolic diversity and antimicrobial potential of endophytic fungi colonizing internal tissues of healthy and brittle leaf diseased (BLD) date palm trees (Phoenix dactylifera L.) widely cultivated in arid zones of Tunisia. A total of 52 endophytic fungi were isolated from healthy and BLD roots of date palm trees, identified based on internal transcribed spacer-rDNA sequence analysis and shown to represent 13 species belonging to five genera. About 36.8% of isolates were shared between healthy and diseased root fungal microbiomes, whereas 18.4 and 44.7% of isolates were specific to healthy and BLD root fungal microbiomes, respectively. All isolates were able to produce at least two of the screened enzymes including amylase, cellulase, chitinase, pectinase, protease, laccase and lipase. A preliminary screening of the isolates using disk diffusion method for antibacterial activity against four Gram-positive and three Gram-negative bacteria and antifungal activities against three phytopathogenic fungi indicated that healthy and BLD root fungal microbiomes displayed interesting bioactivities against examined bacteria and broad spectrum bioactivity against fungal pathogens. Some of these endophytic fungi (17 isolates) were fermented and their extracts were evaluated for antimicrobial potential against bacterial and fungal isolates. Results revealed that fungal extracts exhibited antibacterial activities and were responsible for approximately half of antifungal activities against living fungi. These results suggest a strong link between fungal bioactivities and their secondary metabolite arsenal. EtOAc extracts of Geotrichum candidum and Thielaviopsis punctulata originating from BLD microbiome gave best results against Micrococcus luteus and Bacillus subtilis with minimum inhibitory concentration (MIC, 0.78 mg/mL) and minimum bactericidal concentration (6.25 mg/mL). G. candidum gave the best result against

  18. Fungal Root Microbiome from Healthy and Brittle Leaf Diseased Date Palm Trees (Phoenix dactylifera L.) Reveals a Hidden Untapped Arsenal of Antibacterial and Broad Spectrum Antifungal Secondary Metabolites

    Science.gov (United States)

    Mefteh, Fedia B.; Daoud, Amal; Chenari Bouket, Ali; Alenezi, Faizah N.; Luptakova, Lenka; Rateb, Mostafa E.; Kadri, Adel; Gharsallah, Neji; Belbahri, Lassaad

    2017-01-01

    In this study, we aimed to explore and compare the composition, metabolic diversity and antimicrobial potential of endophytic fungi colonizing internal tissues of healthy and brittle leaf diseased (BLD) date palm trees (Phoenix dactylifera L.) widely cultivated in arid zones of Tunisia. A total of 52 endophytic fungi were isolated from healthy and BLD roots of date palm trees, identified based on internal transcribed spacer-rDNA sequence analysis and shown to represent 13 species belonging to five genera. About 36.8% of isolates were shared between healthy and diseased root fungal microbiomes, whereas 18.4 and 44.7% of isolates were specific to healthy and BLD root fungal microbiomes, respectively. All isolates were able to produce at least two of the screened enzymes including amylase, cellulase, chitinase, pectinase, protease, laccase and lipase. A preliminary screening of the isolates using disk diffusion method for antibacterial activity against four Gram-positive and three Gram-negative bacteria and antifungal activities against three phytopathogenic fungi indicated that healthy and BLD root fungal microbiomes displayed interesting bioactivities against examined bacteria and broad spectrum bioactivity against fungal pathogens. Some of these endophytic fungi (17 isolates) were fermented and their extracts were evaluated for antimicrobial potential against bacterial and fungal isolates. Results revealed that fungal extracts exhibited antibacterial activities and were responsible for approximately half of antifungal activities against living fungi. These results suggest a strong link between fungal bioactivities and their secondary metabolite arsenal. EtOAc extracts of Geotrichum candidum and Thielaviopsis punctulata originating from BLD microbiome gave best results against Micrococcus luteus and Bacillus subtilis with minimum inhibitory concentration (MIC, 0.78 mg/mL) and minimum bactericidal concentration (6.25 mg/mL). G. candidum gave the best result against

  19. Modeling terrestrial carbon and water dynamics across climatic gradients: does plant trait diversity matter?

    Science.gov (United States)

    Pappas, Christoforos; Fatichi, Simone; Burlando, Paolo

    2016-01-01

    Plant trait diversity in many vegetation models is crudely represented using a discrete classification of a handful of 'plant types' (named plant functional types; PFTs). The parameterization of PFTs reflects mean properties of observed plant traits over broad categories ignoring most of the inter- and intraspecific plant trait variability. Taking advantage of a multivariate leaf-trait distribution (leaf economics spectrum), as well as documented plant drought strategies, we generate an ensemble of hypothetical species with coordinated attributes, rather than using few PFTs. The behavior of these proxy species is tested using a mechanistic ecohydrological model that translates plant traits into plant performance. Simulations are carried out for a range of climates representative of different elevations and wetness conditions in the European Alps. Using this framework we investigate the sensitivity of ecosystem response to plant trait diversity and compare it with the sensitivity to climate variability. Plant trait diversity leads to highly divergent vegetation carbon dynamics (fluxes and pools) and to a lesser extent water fluxes (transpiration). Abiotic variables, such as soil water content and evaporation, are only marginally affected. These results highlight the need for revising the representation of plant attributes in vegetation models. Probabilistic approaches, based on observed multivariate whole-plant trait distributions, provide a viable alternative.

  20. Variations in Stable Carbon Isotope Composition and Leaf Traits of Picea schrenkiana var. tianschanica along an Altitude Gradient in Tianshan Mountains, Northwest China

    Directory of Open Access Journals (Sweden)

    Huiwen Zhang

    2014-01-01

    Full Text Available To understand the morphological and physiological responses of leaves to changes in altitudinal gradients, we examined ten morphological and physiological characteristics in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that LA, SD, LPC, and LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla + b, LDMC, LMA, and Narea varied nonlinearly with changes in altitude. With elevation below 2100 m, LNC, Narea, and Chla + b increased, while LDMC and LMA decreased with increasing altitude. When altitude was above 2100 m, these properties showed the opposite patterns. Leaf δ13C was positively correlated with Narea and LNC and negatively correlated with SD and LA, suggesting that leaf δ13C was indirectly controlled by physiological and morphological adjustments along altitudinal gradients. Based on the observed maximum values in LNC, Narea, Chla + b, and LA and the minimum values in LMA and LDMC at the elevation of 2100 m, suggesting higher photosynthetic capacity and greater potential for fast growth under superior optimum zone, we concluded that the best growing elevation for P. schrenkiana var. tianschanica in the Tianshan Mountains was approximately 2100 m.

  1. Tissue-level leaf toughness, but not lamina thickness, predicts sapling leaf lifespan and shade tolerance of tropical tree species

    NARCIS (Netherlands)

    Kitajima, K.; Poorter, L.

    2010-01-01

    Leaf toughness is thought to enhance physical defense and leaf lifespan. Here, we evaluated the relative importance of tissue-level leaf traits vs lamina thickness, as well as their ontogenetic changes, for structure-level leaf toughness and regeneration ecology of 19 tropical tree species. We

  2. Morphological and Physiological Traits of Leaf in Different Drought Resistant Peanut Cultivars%不同抗旱性花生品种的叶片形态及生理特性

    Institute of Scientific and Technical Information of China (English)

    厉广辉; 张昆; 刘风珍; 刘丹丹; 万勇善

    2014-01-01

    [Objective]The main purpose of this paper was to screen leaf traits related to drought resistance, explore the methods of traits index evaluation, and to reveal drought resistance mechanisms of different peanut cultivars. [Method] The drought resistance was studied in twelve peanut cultivars under drought stress and normal irrigation in a pot experiment at seedling stage and a pool culture experiment at pod setting stage. Keeping the water treatments by using weighing at seedling stage and supplemental irrigation based on testing soil moisture at pod setting stage with rain-shedding during drought stress. Leaf morphological and physiological traits including organization structure, thickness, specific leaf weight (SLW), leaf area per plant (PLA), photosynthetic rate (Pn), chlorophyll content under the conditions of normal water supply and drought stress at seedling stage were tested, and the relationship between those traits and drought resistance was studied. Drought resistances of cultivars were scored with drought coefficient of biomass at seedling stage and yield at pod setting stage. Drought resistance mechanisms of leaf were evaluated by traits index.[Result]The results by two years experiments showed that, under drought stress, the drought resistance coefficients of different peanut cultivars were significantly different. Drought resistance at seedling and pod-setting stages was basically identical. According to yield-drought resistance coefficient, twelve peanut cultivars could be divided into 3 grads:high-resistance, including A596, Shanhua 11 and Rugaoxiyangsheng; mid-resistance, including Huayu 20, Nongda 818, Haihua 1, Shanhua 9 and 79266;weak-resistance, including ICG6848, Baisha1016, Hua17 and Penglaiyiwohou. Water stress changed organization structure in leaves, functional leaf area, PLA, Gs, Pn and Tr were reduced, but SLW of peanuts was increased under soil drought stress. A significant difference in leaf traits among peanut cultivars with

  3. Quantitative trait loci for flowering time and morphological traits in multiple populations of Brassica rapa

    NARCIS (Netherlands)

    Lou, P.; Jianjun Zhao, Jianjun; Kim, J.S.; Shen, Shuxing; Pino del Carpio, D.; Song, Xiaofei; Jin, M.; Vreugdenhil, D.; Wang, Xiaowu; Koornneef, M.; Bonnema, A.B.

    2007-01-01

    Wide variation for morphological traits exists in Brassica rapa and the genetic basis of this morphological variation is largely unknown. Here is a report on quantitative trait loci (QTL) analysis of flowering time, seed and pod traits, growth-related traits, leaf morphology, and turnip formation in

  4. Quantitative trait loci for flowering time and morphological traits in multiple populations of Brassica rapa

    NARCIS (Netherlands)

    Lou, P.; Jianjun Zhao, Jianjun; Kim, J.S.; Shen, Shuxing; Pino del Carpio, D.; Song, Xiaofei; Jin, M.; Vreugdenhil, D.; Wang, Xiaowu; Koornneef, M.; Bonnema, A.B.

    2007-01-01

    Wide variation for morphological traits exists in Brassica rapa and the genetic basis of this morphological variation is largely unknown. Here is a report on quantitative trait loci (QTL) analysis of flowering time, seed and pod traits, growth-related traits, leaf morphology, and turnip formation in

  5. Adult nutrition, but not inbreeding, affects male primary sexual traits in the leaf-footed cactus bug Narnia femorata (Hemiptera: Coreidae).

    Science.gov (United States)

    Joseph, Paul N; Sasson, Daniel A; Allen, Pablo E; Somjee, Ummat; Miller, Christine W

    2016-07-01

    Adverse conditions may be the norm rather than the exception in natural populations. Many populations experience poor nutrition on a seasonal basis. Further, brief interludes of inbreeding can be common as population density fluctuates and because of habitat fragmentation. Here, we investigated the effects of poor nutrition and inbreeding on traits that can be very important to reproductive success and fitness in males: testes mass, sperm concentration, and sperm viability. Our study species was Narnia femorata, a species introduced to north-central Florida in the 1950s. This species encounters regular, seasonal changes in diet that can have profound phenotypic effects on morphology and behavior. We generated inbred and outbred individuals through a single generation of full-sibling mating or outcrossing, respectively. All juveniles were provided a natural, high-quality diet of Opuntia humifusa cactus cladode with fruit until they reached adulthood. New adult males were put on a high- or low-quality diet for at least 21 days before measurements were taken. As expected, the low-quality diet led to significantly decreased testes mass in both inbred and outbred males, although there were surprisingly no detectable effects on sperm traits. We did not find evidence that inbreeding affected testes mass, sperm concentration, and sperm viability. Our results highlight the immediate and overwhelming effects of nutrition on testes mass, while suggesting that a single generation of inbreeding might not be detrimental for primary sexual traits in this particular population.

  6. 氮肥水平对不同穗型水稻品种叶片性状的影响%Effect of Different Nitrogen Treatments on Rice Leaf Traits of Different Panicle Type Cultivars

    Institute of Scientific and Technical Information of China (English)

    刘丽霞; 李海波

    2011-01-01

    以直立穗型水稻品种辽粳5号和弯曲穗型水稻品种丰锦为试验材料,研究不同氮肥水平时不同穗型水稻品种叶片性状的影响.结果表明,增施氮肥导致水稻叶面积的增加,增加了个体的光合面积,但是气孔密度明显减小,净光合速率和叶绿素含量显著增大.随着施氮量的增多,不同穗型品种的蒸腾速率和气孔导度都明显下降,且肥力对弯穗型品种的蒸腾速率和气孔导度的影响远比对直穗型品种的影响明显.比叶重不同品种存在显著差异,其大小由品种特性决定.%The leaf traits of different panicle types Japonica rice varieties under two nitrogen levels (zero and high) was studied by using erect panicle type cultivars Laiojing 5 and curved panicle type cultivar Toyonishiki as materials. The results showed that, with the increase of rate of nitrogen fertilization leaf area of different varieties increased; and photosynthetic area of plant increased while stomatal density obviously reduced; and net photosynthetic rate and chlorophyll content increased remarkably. Transpiration rate and gas diffusion conductivity of different panicle type cultivars decreased obviously with the increasing of the application amount of nitrogen, and the effect of the application amount of nitrogen on transpiration rate and gas diffusion conductivity of curved panicle type variety was far higher than that of erect panicle type cultivar. There were significant difference in specific leaf weight of different cultivars and specific leaf weight was mainly decided by cultivars.

  7. Fine Mapping of Carbon Assimilation Rate 8, a Quantitative Trait Locus for Flag Leaf Nitrogen Content, Stomatal Conductance and Photosynthesis in Rice

    Science.gov (United States)

    Adachi, Shunsuke; Yoshikawa, Kazuaki; Yamanouchi, Utako; Tanabata, Takanari; Sun, Jian; Ookawa, Taiichiro; Yamamoto, Toshio; Sage, Rowan F.; Hirasawa, Tadashi; Yonemaru, Junichi

    2017-01-01

    Increasing the rate of leaf photosynthesis is one important approach for increasing grain yield in rice (Oryza sativa). Exploiting the natural variation in CO2 assimilation rate (A) between rice cultivars using quantitative genetics is one promising means to identify genes contributing to higher photosynthesis. In this study, we determined precise location of Carbon Assimilation Rate 8 (CAR8) by crossing a high-yielding indica cultivar with a Japanese commercial cultivar. Fine mapping suggested that CAR8 encodes a putative Heme Activator Protein 3 (OsHAP3) subunit of a CCAAT-box-binding transcription factor called OsHAP3H. Sequencing analysis revealed that the indica allele of CAR8 has a 1-bp deletion at 322 bp from the start codon, resulting in a truncated protein of 125 amino acids. In addition, CAR8 is identical to DTH8/Ghd8/LHD1, which was reported to control rice flowering date. The increase of A is largely due to an increase of RuBP regeneration rate via increased leaf nitrogen content, and partially explained by reduced stomatal limitation via increased stomatal conductance relative to A. This allele also increases hydraulic conductivity, which would promote higher stomatal conductance. This indicates that CAR8 affects multiple physiological aspects relating to photosynthesis. The detailed analysis of molecular functions of CAR8 would help to understand the association between photosynthesis and flowering and demonstrate specific genetic mechanisms that can be exploited to improve photosynthesis in rice and potentially other crops. PMID:28197156

  8. Using plant traits to explain plant-microbe relationships involved in nitrogen acquisition.

    Science.gov (United States)

    Cantarel, Amélie A M; Pommier, Thomas; Desclos-Theveniau, Marie; Diquélou, Sylvain; Dumont, Maxime; Grassein, Fabrice; Kastl, Eva-Maria; Grigulis, Karl; Laîné, Philippe; Lavorel, Sandra; Lemauviel-Lavenant, Servane; Personeni, Emmanuelle; Schloter, Michael; Poly, Franck

    2015-03-01

    It has long been recognized that plant species and soil microorganisms. are tightly linked, but understanding how different species vary in their effects on soil is currently limited. In this study, we identified those. plant characteristics (identity, specific functional traits, or resource acquisition strategy) that were the best predictors of nitrification and denitrification processes. Ten plant populations representing eight species collected from three European grassland sites were chosen for their contrasting plant trait values and resource acquisition strategies. For each individual plant, leaf and root traits and the associated potential microbial activities (i.e., potential denitrification rate [DEA], maximal nitrification rate [NEA], and NH4+ affinity of the microbial community [NHScom]) were measured at two fertilization levels under controlled growth conditions. Plant traits were powerful predictors of plant-microbe interactions, but relevant plant traits differed in relation to the microbial function studied. Whereas denitrification was linked to the relative growth rate of plants, nitrification was strongly correlated to root trait characteristics (specific root length, root nitrogen concentration, and plant affinity for NH4+) linked to plant N cycling. The leaf economics spectrum (LES) that commonly serves as an indicator of resource acquisition strategies was not correlated to microbial activity. These results suggest that the LES alone is not a good predictor of microbial activity, whereas root traits appeared critical in understanding plant-microbe interactions.

  9. Change in hydraulic properties and leaf traits in a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Directory of Open Access Journals (Sweden)

    B. Schuldt

    2011-08-01

    Full Text Available A large-scale replicated throughfall exclusion experiment was conducted in a pre-montane perhumid rainforest in Sulawesi (Indonesia exposing the trees for two years to pronounced soil desiccation. The lack of regularly occurring dry periods and shallow rooting patterns distinguish this experiment from similar experiments conducted in the Amazonian rainforest. We tested the hypotheses that a tree's sun canopy is more affected by soil drought than its shade crown, making tall trees particularly vulnerable even under a perhumid climate, and that extended drought periods stimulate an acclimation in the hydraulic system of the sun canopy. In the abundant and tall tree species Castanopsis acuminatissima (Fagaceae, we compared 31 morphological, anatomical, hydraulic and chemical variables of leaves, branches and the stem together with stem diameter growth between drought and control plots.

    There was no evidence of canopy dieback. However, the drought treatment led to a 30 % reduction in sapwood-specific hydraulic conductivity of sun canopy branches, possibly caused by the formation of smaller vessels and/or vessel filling by tyloses. Drought caused an increase in leaf size, but a decrease in leaf number, and a reduction in foliar calcium content. The δ13C and δ18O signatures of sun canopy leaves gave no indication of a permanent down-regulation of stomatal conductance during the drought, indicating that pre-senescent leaf shedding may have improved the water status of the remaining leaves. Annual stem diameter growth decreased during the drought, while the density of wood in the recently produced xylem increased in both the stem and sun canopy branches (marginally significant. The sun canopy showed a more pronounced drought response than the shade crown indicating that tall trees with a large sun canopy are more vulnerable to drought stress.

    We conclude that the extended drought prompted a number of

  10. Change in hydraulic properties and leaf traits in a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Science.gov (United States)

    Schuldt, B.; Leuschner, C.; Horna, V.; Moser, G.; Köhler, M.; van Straaten, O.; Barus, H.

    2011-08-01

    A large-scale replicated throughfall exclusion experiment was conducted in a pre-montane perhumid rainforest in Sulawesi (Indonesia) exposing the trees for two years to pronounced soil desiccation. The lack of regularly occurring dry periods and shallow rooting patterns distinguish this experiment from similar experiments conducted in the Amazonian rainforest. We tested the hypotheses that a tree's sun canopy is more affected by soil drought than its shade crown, making tall trees particularly vulnerable even under a perhumid climate, and that extended drought periods stimulate an acclimation in the hydraulic system of the sun canopy. In the abundant and tall tree species Castanopsis acuminatissima (Fagaceae), we compared 31 morphological, anatomical, hydraulic and chemical variables of leaves, branches and the stem together with stem diameter growth between drought and control plots. There was no evidence of canopy dieback. However, the drought treatment led to a 30 % reduction in sapwood-specific hydraulic conductivity of sun canopy branches, possibly caused by the formation of smaller vessels and/or vessel filling by tyloses. Drought caused an increase in leaf size, but a decrease in leaf number, and a reduction in foliar calcium content. The δ13C and δ18O signatures of sun canopy leaves gave no indication of a permanent down-regulation of stomatal conductance during the drought, indicating that pre-senescent leaf shedding may have improved the water status of the remaining leaves. Annual stem diameter growth decreased during the drought, while the density of wood in the recently produced xylem increased in both the stem and sun canopy branches (marginally significant). The sun canopy showed a more pronounced drought response than the shade crown indicating that tall trees with a large sun canopy are more vulnerable to drought stress. We conclude that the extended drought prompted a number of medium- to long-term responses in the leaves, branches and the trunk

  11. 干旱和湿润生境中主要优势树种叶片功能性状的比较%Comparison on leaf functional traits of main dominant woody species in wet and dry habitats

    Institute of Scientific and Technical Information of China (English)

    董廷发; 冯玉龙; 类延宝; 张丽坤

    2012-01-01

    Three key leaf functional traits [ leaf dry mass per area (LMA), leaf nitrogen concentration per unit mass (Nmass), and mass-based maximum photosynthetic rate (Amass) ] were measured in 31 woody species from tropical lowland rain forest with high rainfall and from dry-hot valley savanna with low rainfall in southern Yunnan. The results indicated that LMA was 46. 88 - 178.63 and 45. 35-93.16 g · m-2, Amass was 48. 12-176. 65 and 71.38-265.76 nmol · g-1 · s-1, and Nmass was 11.8-36.71 and 12.98-31.78 mg · g-1 in the dry savanna and the wet rain forest, respectively. At the community level, Amass was lower but LMA was higher in the plants of dry habitat than in wet habitat. Nmass was not significantly different between the plants from the two habitats. LMA was negatively associated with Nmass and Amass, in dry habitat; Amass and Nmass were positively associated in both habitats. Our results indicated that correlations among the traits of plants from the same habitat converged although adaptive strategies were different among species. The adaptive strategies of dominant species changed from faster returns on investments in dry mass in wet habitat to slower return to high resource-use efficiency in dry habitat.%以云南南部的沟谷雨林(湿润生境)和干热河谷萨瓦纳(savanna)稀树灌丛(干旱生境)中共31种主要优势木本植物为材料,研究了叶片主要功能性状单位面积叶干重(LMA)、单位干重氮含量(Nmass)和单位干重最大净光合速率(Amass)在2个生境中的差异及各性状间的关系.结果表明:在物种水平上,干旱和湿润生境中各树种的LMA值分别为46.88~178.63和45.35 ~ 93.16 g·m-2;Amass值分别为48.12~176.65和71.38~265.76nmol· g-1·s-1;Nmass值分别为11.8 ~36.71和12.98 ~31.78 mg·g-1;在群落水平上,干旱生境中LMA显著高于湿润生境,而Amass显著低于湿润生境,Nmass在2个生境中差异不显著;在群落尺度上,干旱生境中LMA与Nmass

  12. The photosynthetic capacity in 35 ferns and fern allies: mesophyll CO2 diffusion as a key trait.

    Science.gov (United States)

    Tosens, Tiina; Nishida, Keisuke; Gago, Jorge; Coopman, Rafael Eduardo; Cabrera, Hernán Marino; Carriquí, Marc; Laanisto, Lauri; Morales, Loreto; Nadal, Miquel; Rojas, Roke; Talts, Eero; Tomas, Magdalena; Hanba, Yuko; Niinemets, Ülo; Flexas, Jaume

    2016-03-01

    Ferns and fern allies have low photosynthetic rates compared with seed plants. Their photosynthesis is thought to be limited principally by physical CO2 diffusion from the atmosphere to chloroplasts. The aim of this study was to understand the reasons for low photosynthesis in species of ferns and fern allies (Lycopodiopsida and Polypodiopsida). We performed a comprehensive assessment of the foliar gas-exchange and mesophyll structural traits involved in photosynthetic function for 35 species of ferns and fern allies. Additionally, the leaf economics spectrum (the interrelationships between photosynthetic capacity and leaf/frond traits such as leaf dry mass per unit area or nitrogen content) was tested. Low mesophyll conductance to CO2 was the main cause for low photosynthesis in ferns and fern allies, which, in turn, was associated with thick cell walls and reduced chloroplast distribution towards intercellular mesophyll air spaces. Generally, the leaf economics spectrum in ferns follows a trend similar to that in seed plants. Nevertheless, ferns and allies had less nitrogen per unit DW than seed plants (i.e. the same slope but a different intercept) and lower photosynthesis rates per leaf mass area and per unit of nitrogen.

  13. Responses of leaf functional traits and nitrogen and phosphorus stoichiometry in Abies fabiri seedlings in Gongga Mountain to simulated nitrogen deposition%峨眉冷杉幼苗叶片功能特征及其N、P化学计量比对模拟大气氮沉降的响应

    Institute of Scientific and Technical Information of China (English)

    羊留冬; 王根绪; 杨阳; 杨燕

    2012-01-01

    Abies fabiri is one of the dominant conifers in the subalpine area of western Sichuan Province, Southwest China. Taking A. Fabiri seedlings as test materials, this paper studied their leaf functional traits and N and P stoichiometry under effects of simulated nitrogen deposition. To simulate nitrogen deposition, ammonium nitrate solution (50 kg N ? Hm-2? A-1) was weekly sprayed over the growth season (from May to October) of 2009 and 2010. After the two growth seasons, the total biomass, leaf dry weigh, leaf mass ratio, leaf N and P concentrations, and leaf N:P ratio of the seedlings under ammonium nitrate spraying increased by 11. 29% , 46. 70% , 41.40% , 37. 30% , 22. 33% and 6. 43% , respectively, while specific leaf area (SLA) de creased by 6. 61% , as compared with the control. There existed significant differences in the leaf dry weigh, leaf mass ratio, leaf N concentration, and leaf N : P ratio between ammonium nitrate spraying and the control, and the leaf dry weight had a strong linear correlation with leaf N con centration. The total biomass, leaf dry weight, leaf N and P concentrations, and leaf N : P ratio of seedlings under ammonium nitrate spraying were higher in the second growth season than in the first growth season. This study demonstrated that nitrogen deposition promoted the leaf growth of A. Fabiri seedlings significantly, and increased the leaf N and P concentrations and leaf N : P ratio. However, the variation of leaf N : P ratio under nitrogen supply suggested that the seedling growth was still limited by the shortage of N supply. It was suggested that A. Fabiri seedlings had cumulative effect for N.%通过人工施氮模拟大气氮沉降,研究了施氮对峨眉冷杉(Abies fabiri)幼苗叶片功能特征、氮和磷含量及其化学计量比的影响,以及幼苗对氮素的积累效应.结果表明:经过2个生长季节的施氮处理(2009年和2010年,N2)幼苗的总生物量、叶干重、叶重比、叶片氮和磷含量及

  14. The energetic and carbon economic origins of leaf thermoregulation.

    Science.gov (United States)

    Michaletz, Sean T; Weiser, Michael D; McDowell, Nate G; Zhou, Jizhong; Kaspari, Michael; Helliker, Brent R; Enquist, Brian J

    2016-08-22

    Leaf thermoregulation has been documented in a handful of studies, but the generality and origins of this pattern are unclear. We suggest that leaf thermoregulation is widespread in both space and time, and originates from the optimization of leaf traits to maximize leaf carbon gain across and within variable environments. Here we use global data for leaf temperatures, traits and photosynthesis to evaluate predictions from a novel theory of thermoregulation that synthesizes energy budget and carbon economics theories. Our results reveal that variation in leaf temperatures and physiological performance are tightly linked to leaf traits and carbon economics. The theory, parameterized with global averaged leaf traits and microclimate, predicts a moderate level of leaf thermoregulation across a broad air temperature gradient. These predictions are supported by independent data for diverse taxa spanning a global air temperature range of ∼60 °C. Moreover, our theory predicts that net carbon assimilation can be maximized by means of a trade-off between leaf thermal stability and photosynthetic stability. This prediction is supported by globally distributed data for leaf thermal and photosynthetic traits. Our results demonstrate that the temperatures of plant tissues, and not just air, are vital to developing more accurate Earth system models.

  15. Agronomic Traits and Wheat Leaf Rust Resistance of Ten Turkey Wheat Accessions%土耳其8个小麦品种农艺性状及抗叶锈性分析

    Institute of Scientific and Technical Information of China (English)

    刘彦慧; 赵轩宇; 杨文香; 刘大群

    2012-01-01

    为确定8个来自土耳其的普通小麦品种在我国的应用前景,对其进行全生育期农艺性状观察,并利用44个以Thatcher为背景的近等基因系(单基因系)作为已知基因的鉴别寄主,接种8个小麦叶锈菌致病型进行苗期抗叶锈基因推导,结合成株期抗病鉴定,初步明确了这些品种(系)的抗性和可能携带的抗病基因.利用20个与Lr基因紧密连锁或共分离的分子标记,对8个土耳其小麦品种进行抗叶锈病基因的进一步鉴定.推测YJ000900中可能含有Lr1、Lr3、Lr17、Lr20;YJ000906中可能含有Lr1、Lr17、Lr20;YJ000901、YJ000902、YJ000904、YJ000905、YJ000907中可能含有Lr1;8个材料中均不含Lr9、Lr19、Lr20、Lr21、Lr24、Lr26、Lr28、Lr29、Lr34、Lr35、Lr37、Lr38和Lr47基因.结果表明,来自土耳其的8个小麦材料具有较差的抗叶锈性、抗寒和抗倒伏能力,而且产量低,不适宜于太规模推广种植,也不能作为我国小麦抗叶锈的抗源使用.%To evaluate the leaf rust resistance and the application prospect of eight wheat cultivars from Turkey, the agronomic traits were surveyed in whole growth period for two years and forty-four near isogenic lines (or single gene lines) in Thatcher background with known wheat leaf rust resistance genes were used as differential hosts. All genotypes were inoculated with eight pathotypes of Puccinina triticina at seedling stage. The results indicated that Lr1 ,Lr3,Lr17,Lr20 and some unknown resistance genes might present in the 8 accessions. As revealed by 20 molecular markers closely linked or co-segregated with part of the known Lr genes,the 8 accessions from Turkey were postulated to carry 4 resistance genes, such as Lr1 , Lr3 , Lr1 7 and Lr20 in YJ000900 , Lr1 , Lr1 7 and Lr2O in YJ000906,Lr7 in YJ000901 , YJ000902 , Y J000904 , Y J000905 and YJ000907. However, Lr9 , Lr19, Lr20,Lr21, Lr24 , Lr26 ,Lr28 ,Lr29 ,Lr34 ,Lr35, Lr37,Lr38 and Lr47 were not detected in the 8 accessions

  16. Interspecific Difference and Geographic Variance in Leaf Trait of Fenghuang Dancong Tea Cultivars in Eastern Guangdong Province%广东凤凰单枞茶树品种(系)叶片主要性状的种间差异和地域变异研究

    Institute of Scientific and Technical Information of China (English)

    王桔红; 庄东红; 马瑞君; 吴泽容

    2014-01-01

    对广东潮州凤凰山区不同地域的50种凤凰单枞茶树品系的叶缘锯齿数、侧脉数、叶形、叶绿素含量、叶面积(LA)、叶干物质量(LDMC)、比叶面积(SLA)等叶片形态和功能性状进行了比较研究,并对不同海拔地带的12种凤凰单枞茶树主要叶片性状进行了地域变异研究。结果显示,50种凤凰茶树叶片形状为卵圆形至长卵形(叶形指数1.99~3.16),叶绿素含量平均为64.348(SPAD测定读数),平均单叶面积24.237 cm2,叶干物质含量40.65%,比叶面积80.947 cm2·g-1。50种凤凰单枞茶树的叶面积变异最大(变异系数为21.12%),比叶面积变异次之(18.3%),叶形状(9.8%)和叶绿素含量(10.4%)变异较小,叶干物质含量变异最小(5.9%);南馥茶园的兰花香、柚花香、宋种、八仙、桂花香、夜来香、蜜兰香等品系叶片单位面积合成的有机物质较多,对外界资源有效利用率较高;南馥茶园的玉兰香、水仙、姜花香、杨梅叶和区山塘茶园的玉兰香等品系叶片单位面积合成的有机物较少,对外界资源有效利用率较低;高海拔地带的部分凤凰单枞茶树具有叶面积大、叶干物质含量少、比叶面积大、叶绿素含量多的趋势,表明种植地域的海拔对凤凰单枞茶树叶片性状有较大影响。%Leaf traits are basic and important characters in the ecological strategies of plants. In this paper, leaf traits including leaf vein, serration of leaf margin, index of leaf shape, chlorophyll content, leaf area (LA), leaf dry matter content (LDMC), specific leaf area (SLA) of 50 Fenghuang Dancong tea cultivars in eastern Guangdong were investigated, and while geographic variance in leaf trait of 12 tea cultivars from three altitudes were detected to provide basic information for cultivation of Fenghuang Dancong tea. The results showed that the leaf shape was from ovate to long ovate (index of

  17. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  18. Inferring climate from angiosperm leaf venation networks.

    Science.gov (United States)

    Blonder, Benjamin; Enquist, Brian J

    2014-10-01

    Leaf venation networks provide an integrative linkage between plant form, function and climate niche, because leaf water transport underlies variation in plant performance. Here, we develop theory based on leaf physiology that uses community-mean vein density to predict growing season temperature and atmospheric CO2 concentration. The key assumption is that leaf water supply is matched to water demand in the local environment. We test model predictions using leaves from 17 temperate and tropical sites that span broad climatic gradients. We find quantitative agreement between predicted and observed climate values. We also highlight additional leaf traits that may improve predictions. Our study provides a novel approach for understanding the functional linkages between functional traits and climate that may improve the reconstruction of paleoclimate from fossil assemblages.

  19. NARROW LEAF 7 controls leaf shape mediated by auxin in rice

    NARCIS (Netherlands)

    Fujino, Kenji; Matsuda, Yasuyuki; Ozawa, Kenjirou; Nishimura, Takeshi; Koshiba, Tomokazu; Fraaije, Marco W.; Sekiguchi, Hiroshi

    2008-01-01

    Elucidation of the genetic basis of the control of leaf shape could be of use in the manipulation of crop traits, leading to more stable and increased crop production. To improve our understanding of the process controlling leaf shape, we identified a mutant gene in rice that causes a significant de

  20. Experimental evidence that the Ornstein-Uhlenbeck model best describes the evolution of leaf litter decomposability.

    Science.gov (United States)

    Pan, Xu; Cornelissen, Johannes H C; Zhao, Wei-Wei; Liu, Guo-Fang; Hu, Yu-Kun; Prinzing, Andreas; Dong, Ming; Cornwell, William K

    2014-09-01

    Leaf litter decomposability is an important effect trait for ecosystem functioning. However, it is unknown how this effect trait evolved through plant history as a leaf 'afterlife' integrator of the evolution of multiple underlying traits upon which adaptive selection must have acted. Did decomposability evolve in a Brownian fashion without any constraints? Was evolution rapid at first and then slowed? Or was there an underlying mean-reverting process that makes the evolution of extreme trait values unlikely? Here, we test the hypothesis that the evolution of decomposability has undergone certain mean-reverting forces due to strong constraints and trade-offs in the leaf traits that have afterlife effects on litter quality to decomposers. In order to test this, we examined the leaf litter decomposability and seven key leaf traits of 48 tree species in the temperate area of China and fitted them to three evolutionary models: Brownian motion model (BM), Early burst model (EB), and Ornstein-Uhlenbeck model (OU). The OU model, which does not allow unlimited trait divergence through time, was the best fit model for leaf litter decomposability and all seven leaf traits. These results support the hypothesis that neither decomposability nor the underlying traits has been able to diverge toward progressively extreme values through evolutionary time. These results have reinforced our understanding of the relationships between leaf litter decomposability and leaf traits in an evolutionary perspective and may be a helpful step toward reconstructing deep-time carbon cycling based on taxonomic composition with more confidence.

  1. 青藏高原东缘披针叶黄华叶片形态特征对海拔变化的响应%Response of leaf morphology traits of Thermopsis lanceolata to elevation gradient in the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    武瑞鑫; 邵新庆; 钟梦莹; 潘多; 李超群; 张德罡

    2016-01-01

    In order to reveal the responding mechanism of leaf morphology traits of Thermopsis lanceolata to altitude gradient in the Qinghai-Tibet Plateau,the paper reported the changes of leaf length,leaf width,leaf are-a,leaf perimeter,leaf thickness,leaf dry mass,specific leaf weight and specific leaf area of Thermopsis lanceolata under different altitude gradient,and analyzed the response pattern of leaf morphology traits to altitude gradi-ent.The results showed that soil water content,soil total N content and soil total organic matter increased with altitude increase.The leaf thickness in low altitude was higher than that in high altitude (P <0.05 );the leaf length,leaf width,leaf area and leaf perimeter decreased with the altitude increase.Altitude had significantly correlation with soil water content,pH,total N and total organic matter (P <0.05);the leaf length and leaf area were mainly effected by pH and these had significant correlation with soil water content,pH and total organic matter (P <0.05);Leaf thickness mainly effected by light intensity (R=0.641,P <0.05)and it negatively cor-related with altitude,light intensity and soil total N (P <0.05);the leaf biomass was mainly effected by air tem-perature,especially by soil water content (R=0.856,P <0.01)and it had significantly correlation with soil wa-ter content (P <0.05 ).Thermopsis lanceolata reduced the leaf size and leaf thickness to adapte environment change,the leaf showed miniaturization with the altitude increase.%为揭示青藏高原地区披针叶黄华叶片形态特征对海拔梯度的响应机制,研究了不同海拔梯度对披针叶黄华叶长、叶宽、叶面积、叶周长、叶厚、叶干重、比叶重和比叶面积的影响,分析了披针叶黄华叶片形态特征对海拔的响应规律。结果表明:随着海拔的升高,土壤含水量、全氮含量和有机质增加;低海拔地区披针叶黄华的叶厚显著高于高海拔的地区;叶长、

  2. Some traits of low temperature germplasm wheat under extremely unfavorable weather conditions

    Institute of Scientific and Technical Information of China (English)

    张嵩午; 王长发; 冯佰利; 苗芳; 周春菊; 张荣萍

    2001-01-01

    Through a long-term observation on the canopy temperature and some traits of wheat the temperature germplasm of wheat was found to result in the wheats having either a high or a low plant temperature. Under normal weather conditions, the wheat having a low temperature germplasm (LTG) demonstrated several advantageous physiologi-cal and agronomic traits than those having a high temperature germplasm (HTG). Under the extremely unfavorableweather conditions, such as rainy weather or severe drought, LTG wheat still could maintain its superiority to HTG wheat in physiological and agronomic traits including leaf functional duration, chlorophyll content, malondialdehyde content, transpiration rate, net photosynthesis rate, root vitality and kernel plumpness. The wide adaptability of LTG wheat to awide range of meteoro-ecological conditions could provide a valuable germplasm in breeding of good strains with broad-spectrum stress resistance.

  3. LeafJ: an ImageJ plugin for semi-automated leaf shape measurement.

    Science.gov (United States)

    Maloof, Julin N; Nozue, Kazunari; Mumbach, Maxwell R; Palmer, Christine M

    2013-01-21

    High throughput phenotyping (phenomics) is a powerful tool for linking genes to their functions (see review and recent examples). Leaves are the primary photosynthetic organ, and their size and shape vary developmentally and environmentally within a plant. For these reasons studies on leaf morphology require measurement of multiple parameters from numerous leaves, which is best done by semi-automated phenomics tools. Canopy shade is an important environmental cue that affects plant architecture and life history; the suite of responses is collectively called the shade avoidance syndrome (SAS). Among SAS responses, shade induced leaf petiole elongation and changes in blade area are particularly useful as indices. To date, leaf shape programs (e.g. SHAPE, LAMINA, LeafAnalyzer, LEAFPROCESSOR) can measure leaf outlines and categorize leaf shapes, but can not output petiole length. Lack of large-scale measurement systems of leaf petioles has inhibited phenomics approaches to SAS research. In this paper, we describe a newly developed ImageJ plugin, called LeafJ, which can rapidly measure petiole length and leaf blade parameters of the model plant Arabidopsis thaliana. For the occasional leaf that required manual correction of the petiole/leaf blade boundary we used a touch-screen tablet. Further, leaf cell shape and leaf cell numbers are important determinants of leaf size. Separate from LeafJ we also present a protocol for using a touch-screen tablet for measuring cell shape, area, and size. Our leaf trait measurement system is not limited to shade-avoidance research and will accelerate leaf phenotyping of many mutants and screening plants by leaf phenotyping.

  4. Relationship of Leaf Photosynthetic Characteristics and Root Physiological Traits with Grain Yield in Super Rice%超级稻叶片光合特性和根系生理性状与产量的关系

    Institute of Scientific and Technical Information of China (English)

    付景; 陈露; 黄钻华; 王志琴; 杨建昌

    2012-01-01

    为阐明超级稻产量形成机制,以4个超级稻品种[两优培九和Ⅱ优084(杂交籼稻)、淮稻9号和武粳15(粳稻)]为材料,2个高产品种[汕优63(杂交籼稻)和扬辐粳8号(粳稻)]为对照,观测了不同生育时期叶片光合性状和根系生理性状的变化特点.结果表明,4个超级稻品种的平均总颖花量和产量较两个对照品种分别高出43.5%和16.1%,但超级稻的结实率较对照品种低15.3个百分点.超级稻品种在生育前期叶片中叶绿素a含量、叶绿素b含量、总叶绿索含量、类胡萝卜素含量、光合速率、蒸腾速率、气孔导度和根系中单位干重根系活力、每株根系活力、总根系吸收面积、活跃吸收面积和比表面积均高于对照品种,而在生育后期以上性状指标下降速率大于各自对照品种,直至齐穗后20 d前以上性状指标均小于各自对照品种.说明超级稻强大的产量库容与其生育前中期较强的叶片光合能力和较好的根系生理性状密切相关,生育后期叶片光合能力和根系生理活性下降快导致其结实率下降,从而限制了其产量潜力的发挥.提高生育后期特别是结实后期根系生理活性是进一步提高超级稻产量的重要途径.%The success in super rice breeding has been considered as a great progress in rice production in China. This study aimed to understand the mechanism underlying the yield formation of super rice. Four super rice cultivars, Liangyoupeijiu and Ilyou 084 (indica hybrids), Huaidao 9 and Wujing 15 (japonica), and two elite check cultivars, Shanyou 63 (Mica hybrids) and Yangfujing 8 (japonica), were grown in field. Leaf photosynthetic characteristics and root physiological traits were investigated at different growth stages. The results showed that average total spilcelet number and grain yield of the four super rice cultivars were 43.5% and 16.1%, respectively, more than those of two elite check cultivars, but the seed

  5. Leaf structure traits and their correlation of five tree seedlings of Fagaceae family%壳斗科五树种幼苗叶片结构型性状及其相关关系

    Institute of Scientific and Technical Information of China (English)

    赵广东; 李超; 史作民; 王兵; 邓宗富; 陈和东; 夏晨

    2016-01-01

    After sand reservoir in the condition of low temperature and cultivation in the greenhouse of the collected seeds, 5 tree species (Castanopsis fargesii, C. sclerophylla, Castanea henryi, C. mollissima and Quercus acutissima) seedlings of Fagaceae family in the mid-subtropical zone of China were transplanted into the common garden. The leaf size, leaf thick-ness, specific leaf area, leaf dry matter content, leaf nitrogen concentration, leaf phosphorus concentration, ratio of leaf ni-trogen and phosphorus concentration and their correlation of two-year old seedlings in the growing season were investigated in this paper. The results were as follows:(1)The leaf size and specific leaf area of Castanea henryi were the maximum, its leaf nitrogen concentration was the highest and its leaf dry matter content was the lowest. The leaf size of Castanopsis fargesii was the minimum, its leaf nitrogen concentration and leaf phosphorus concentration were the lowest. The leaf thickness and specific leaf area of C. sclerophylla was the minimum and its leaf dry matter content was the highest. For C. mollissima seed-lings, the leaf thickness was the minimum. In the meanwhile, there was no significant difference of the ratio of leaf nitrogen and phosphorus concentration among the 5 tree seedlings. (2)Pearson and linear regression analysis indicated that leaf sizes of the 5 tree seedlings were in a highly significant positive correlation with leaf nitrogen concentration(P0.1)。(2)Pearson相关和线性回归分析表明,壳斗科5树种幼苗的叶面积与叶氮浓度极显著正相关( P<0.01),并与比叶面积显著正相关( P<0.05);叶厚度与比叶面积极显著负相关( P<0.01),其与叶干物质含量显著正相关(P<0.05);比叶面积与叶干物质含量极显著负相关(P<0.01),并与叶氮浓度极显著正相关( P<0.01),同时与叶磷浓度显著负相关( P<0.05);叶氮浓度与叶干物质含量、叶磷浓度分别为显著负相关( P<0.05)

  6. Relationships between phyllosphere bacterial communities and plant functional traits in a neotropical forest.

    Science.gov (United States)

    Kembel, Steven W; O'Connor, Timothy K; Arnold, Holly K; Hubbell, Stephen P; Wright, S Joseph; Green, Jessica L

    2014-09-23

    The phyllosphere--the aerial surfaces of plants, including leaves--is a ubiquitous global habitat that harbors diverse bacterial communities. Phyllosphere bacterial communities have the potential to influence plant biogeography and ecosystem function through their influence on the fitness and function of their hosts, but the host attributes that drive community assembly in the phyllosphere are poorly understood. In this study we used high-throughput sequencing to quantify bacterial community structure on the leaves of 57 tree species in a neotropical forest in Panama. We tested for relationships between bacterial communities on tree leaves and the functional traits, taxonomy, and phylogeny of their plant hosts. Bacterial communities on tropical tree leaves were diverse; leaves from individual trees were host to more than 400 bacterial taxa. Bacterial communities in the phyllosphere were dominated by a core microbiome of taxa including Actinobacteria, Alpha-, Beta-, and Gammaproteobacteria, and Sphingobacteria. Host attributes including plant taxonomic identity, phylogeny, growth and mortality rates, wood density, leaf mass per area, and leaf nitrogen and phosphorous concentrations were correlated with bacterial community structure on leaves. The relative abundances of several bacterial taxa were correlated with suites of host plant traits related to major axes of plant trait variation, including the leaf economics spectrum and the wood density-growth/mortality tradeoff. These correlations between phyllosphere bacterial diversity and host growth, mortality, and function suggest that incorporating information on plant-microbe associations will improve our ability to understand plant functional biogeography and the drivers of variation in plant and ecosystem function.

  7. Effects of long-term nitrogen addition on photosynthetic characteristics and leaf traits of Stipa baicalensis in Inner Mongolia,China%贝加尔针茅光合特征与叶片功能特性对长期氮添加的响应

    Institute of Scientific and Technical Information of China (English)

    刘红梅; 李洁; 皇甫超河; 陈新微; 杨殿林

    2016-01-01

    以贝加尔针茅草甸草原建群种贝加尔针茅为研究对象,通过一个连续6年氮添加野外控制试验,设置5个氮素处理:N0(0 kg N/hm2)、N30(30 kg N/hm2)、N50(50 kg N/hm2)、N100(100 kg N/hm2)、N150(150 kg N/hm2),探讨氮沉降变化对贝加尔针茅种群光合特性与叶片功能特性变化规律及其影响因子。结果表明,氮素添加变化显著影响贝加尔针茅的净光合速率等光合特性,氮素添加处理净光合速率(net photosynthetic rate,Pn )、气孔导度(stomatal conductance,Gs )、蒸腾速率(transpiration rate,Tr )、光合氮利用效率(photosynthetic nitrogen use effi-ciency,PNUE)和光合能量利用效率(photosynthetic energy use efficiency,PEUE)均低于或显著低于无氮素添加处理。氮素添加处理叶片比叶面积(specific leaf area,SLA)、叶片 N 含量(leaf N content,N mass )、建成成本(leaf construction cost,CC mass )、叶片 N∶P 均高于或显著高于无氮素添加处理。相关分析表明,5个氮素处理的 Pn 与Gs 、Tr 、PNUE、PEUE、叶片 P 含量(leaf P content,P mass )、土壤 N ∶P 呈显著正相关,与叶片比叶面积(SLA)、N mass 、CC mass 、土壤含水量、土壤 pH 值呈极显著负相关;叶片 N mass 与 SLA、CC mass 、土壤 N∶P 呈显著正相关,与PNUE、PEUE、P mass 、土壤含水量、土壤 pH 值呈显著负相关。综合以上研究表明,长期氮添加会降低贝加尔针茅净光合速率、养分利用效率,提高叶片建成成本和叶片 N∶P,土壤含水量和土壤 pH 值是引起这种改变发生的主要因子。%Atmospheric nitrogen deposition is an important component phenomenon of global change,and in-duces a series of ecological problems.We conducted a field manipulation experiment to study the photosynthet-ic response and change in leaf functional traits after long-term nitrogen addition in

  8. Variação temporal de características morfológicas de folhas em dez espécies do Parque Nacional da Restinga de Jurubatiba, Macaé, RJ, Brasil Temporal variation of morphological leaf traits in ten species from Restinga of Jurubatiba National Park, Macaé, Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Bruno Henrique Pimentel Rosado

    2007-09-01

    Full Text Available Ordenar espécies em relação a um contínuo de variação de características foliares pode ser útil para inferir sobre a suscetibilidade de uma comunidade a alterações na disponibilidade de recursos e/ou condições ambientais ao longo do tempo. Dez espécies lenhosas de restinga foram acompanhadas quanto à variação temporal de atributos morfológicos foliares. Folhas de dez espécies de restinga foram coletadas nos meses de fevereiro, abril e agosto ao longo de três anos para caracterização da variação temporal da massa de folha por unidade de área (MFA, suculência (SUC, espessura (ESP e densidade (DEN. As espécies apresentaram uma tendência de valores mais elevados para as características estudadas nos meses mais secos. A partir da comparação sazonal e interanual da MFA, SUC, ESP e DEN sugerimos que a natureza das respostas das plantas à heterogeneidade temporal na disponibilidade de água foi convergente, independentemente do padrão fenológico de produção foliar e filogenia. Portanto, a similaridade observada entre as espécies na dinâmica temporal dos atributos foliares indica a disponibilidade hídrica como um fator determinante para o sucesso na ocupação das planícies arenosas costeiras do norte fluminense.Ranking species in relation to a continuum of leaf-trait variation can be useful to infer community susceptibility to changes in resource availability and/or environmental conditions over time. Leaves of ten woody restinga species were sampled in February, April and August over a period of 3 years to characterize temporal variability of leaf mass per area (LMA, succulence (SUC, thickness (THI and density (DEN. The species showed a trend toward higher leaf-trait values in dry months during the three-year study. Based on seasonal and interannual comparison of LMA, SUC, THI and DEN we suggest that plant responses to temporal heterogeneity in water availability were convergent, independent of leaf phenological

  9. METHODS OF BIOMONITORING IN URBAN ENVIRONMENT: LEAF AREA AND FRACTAL DIMENSION

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2015-12-01

    Full Text Available In urban conditions, we investigated several leaf traits (leaf area, specific leaf area, fractal dimension and specific leaf weight on Taraxacum officinale, Tilia tomentosa, Aesculus hippocastanum and Ambrosia artemisiifolia. The analyzed organs were mature leaves, on the first indications of senescence. This study used an exact, inexpensive and efficient in terms of costs alternative methods for determining the leaf parameters. On the other hand, this paper presents an application of the leaf area and fractal dimension in the analysis of leaf shape. Our results show that leaf area and fractal dimension are sensitive parameters that can be effectively used in biomonitoring.

  10. Genetic control of leaf curl in maize.

    Science.gov (United States)

    Entringer, G C; Guedes, F L; Oliveira, A A; Nascimento, J P; Souza, J C

    2014-03-17

    Among the many implications of climatic change on agriculture, drought is expected to continue to have a major impact on agribusinesses. Leaf curling is an anatomical characteristic that might be potentially used to enhance plant tolerance to water deficit. Hence, we aimed to study the genetic control of leaf curl in maize. From 2 contrasting inbred lines for the trait, generations F1, F2, and the backcrosses were obtained. All of these generations were evaluated in a randomized block design with 2 replicates. Leaf curl samples were collected from 3 leaves above the first ear at the tasseling stage, and quantified by dividing the width of the leaf blade with natural curling against its extended width. The mean and variance components were estimated by the weighted least square method. It was found that the trait studied has predominance of the additive effects, with genetic control being attributed to few genes that favor selection and exhibit minimal influence from the environment.

  11. Phylloseptin-PBa—A Novel Broad-Spectrum Antimicrobial Peptide from the Skin Secretion of the Peruvian Purple-Sided Leaf Frog (Phyllomedusa Baltea Which Exhibits Cancer Cell Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Yuantai Wan

    2015-12-01

    Full Text Available Antimicrobial peptides from amphibian skin secretion display remarkable broad-spectrum antimicrobial activity and are thus promising for the discovery of new antibiotics. In this study, we report a novel peptide belonging to the phylloseptin family of antimicrobial peptides, from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea, which was named Phylloseptin-PBa. Degenerate primers complementary to putative signal peptide sites of frog skin peptide precursor-encoding cDNAs were designed to interrogate a skin secretion-derived cDNA library from this frog. Subsequently, the peptide was isolated and identified using reverse phase HPLC and MS/MS fragmentation. The synthetic replicate was demonstrated to have activity against S. aureus, E. coli and C. albicans at concentrations of 8, 128 and 8 mg/L, respectively. In addition, it exhibited anti-proliferative activity against the human cancer cell lines, H460, PC3 and U251MG, but was less active against a normal human cell line (HMEC. Furthermore, a haemolysis assay was performed to assess mammalian cell cytotoxicity of Phylloseptin-PBa. This peptide contained a large proportion of α-helical domain, which may explain its antimicrobial and anticancer activities.

  12. Barley Leaf Area and Leaf Growth Rates Are Maximized during the Pre-Anthesis Phase

    Directory of Open Access Journals (Sweden)

    Ahmad M. Alqudah

    2015-04-01

    Full Text Available Leaf developmental traits are an important component of crop breeding in small-grain cereals. Surprisingly, little is known about the genetic basis for the differences in barley (Hordeum vulgare L. leaf development. The two barley row-type classes, i.e., two- and six-rowed, show clear-cut differences in leaf development. To quantify these differences and to measure the genetic component of the phenotypic variance for the leaf developmental differences in both row-type classes we investigated 32 representative spring barley accessions (14 two- and 18 six-rowed accessions under three independent growth conditions. Leaf mass area is lower in plants grown under greenhouse (GH conditions due to fewer, smaller, and lighter leaf blades per main culm compared to pot- and soil-grown field plants. Larger and heavier leaf blades of six-rowed barley correlate with higher main culm spike grain yield, spike dry weight, and harvest index; however, smaller leaf area (LA in two-rowed barley can be attributed to more spikes, tillers, and biological yield (aboveground parts. In general, leaf growth rate was significantly higher between awn primordium and tipping stages. Moderate to very high broad-sense heritabilities (0.67–0.90 were found under all growth conditions, indicating that these traits are predominantly genetically controlled. In addition, our data suggests that GH conditions are suitable for studying leaf developmental traits. Our results also demonstrated that LA impacts single plant yield and can be reconsidered in future breeding programs. Six-rowed spike 1 (Vrs1 is the major determinate of barley row-types, the differences in leaf development between two- and six-rowed barleys may be attributed to the regulation of Vrs1 in these two classes, which needs further testing.

  13. Plant functional traits predict green roof ecosystem services.

    Science.gov (United States)

    Lundholm, Jeremy; Tran, Stephanie; Gebert, Luke

    2015-02-17

    Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

  14. Freshwater Biological Traits Database (Traits)

    Science.gov (United States)

    The traits database was compiled for a project on climate change effects on river and stream ecosystems. The traits data, gathered from multiple sources, focused on information published or otherwise well-documented by trustworthy sources.

  15. Measuring autistic traits in the general population: a systematic review of the Autism-Spectrum Quotient (AQ) in a nonclinical population sample of 6,900 typical adult males and females.

    Science.gov (United States)

    Ruzich, Emily; Allison, Carrie; Smith, Paula; Watson, Peter; Auyeung, Bonnie; Ring, Howard; Baron-Cohen, Simon

    2015-01-01

    The Autism-Spectrum Quotient (AQ) is a self-report measure of autistic traits. It is frequently cited in diverse fields and has been administered to adults of at least average intelligence with autism and to nonclinical controls, as well as to clinical control groups such as those with schizophrenia, prosopagnosia, anorexia, and depression. However, there has been no empirical systematic review of the AQ since its inception in 2001. The present study reports a comprehensive systematic review of the literature to estimate a reliable mean AQ score in individuals without a diagnosis of an autism spectrum condition (ASC), in order to establish a reference norm for future studies. A systematic search of computerized databases was performed to identify studies that administered the AQ to nonclinical participant samples representing the adult male and female general population. Inclusion was based on a set of formalized criteria that evaluated the quality of the study, the usage of the AQ, and the population being assessed. After selection, 73 articles, detailing 6,934 nonclinical participants, as well as 1,963 matched clinical cases of ASC (from available cohorts within each individual study), were analyzed. Mean AQ score for the nonclinical population was 16.94 (95% CI 11.6, 20.0), while mean AQ score for the clinical population with ASC was found to be 35.19 (95% CI 27.6, 41.1). In addition, in the nonclinical population, a sex difference in autistic traits was found, although no sex difference in AQ score was seen in the clinical ASC population. These findings have implications for the study of autistic traits in the general population. Here, we confirm previous norms with more rigorous data and for the first time establish average AQ scores based on a systematic review, for populations of adult males and females with and without ASC. Finally, we advise future researchers to avoid risk of bias by carefully considering the recruitment strategy for both clinical and

  16. Leaf structure and production trait of wild tea (Camellia sinensis) from Fusui county%扶绥野生茶树叶片结构与生产性状分析

    Institute of Scientific and Technical Information of China (English)

    邱勇娟; 李火坤; 陈佳; 李凤英; 赖兆荣; 覃秀菊

    2015-01-01

    Objective]The leaf structure of wild tea (Camellia sinensis) was anatomized and analyzed to provide references for high-quality tea production,identification of breeding sources,and cultivation of tea in Guangxi Province.[Method]The anatomy structures of leaves from 9 strains of wild tea from Fusui of Guangxi were studied via paraffin section and optical microtechnique to compare the anti-adversity, potential productivity, tea-making suitability,and greenness-keeping. [Result]The results showed that there was significant variation in anatomy structures of leaves, pro-duction-increase trait and productivity characteristics among 9 wild tea strains. The thickness of the upper epidermic cells ranged from 19.31 to 26.26 μm,while the mesophyll from 189.47 to 335.37 μm,spongy tissue from 121.04 to 238.32 μm,and productivity index from 1268.96 to 3105.60, respectively. Variance analysis showed that the differ-ences in structural characteristics and production index among different strains reached extremely significant level (P<0.01). The resistance states were the strongest in Gubiao 7 and 8, and the productions were the highest in Gubiao 8 and 6 , and the most appropriate ones for black tea were Gubiao 8 and 1 . [Conclusion]The leaves of 9 strains of Fusui wild tea are partial drought type structure, having strong ability of drought resistance , cold resistance and resis-tance to diseases and pests. Owing to their superior comprehensive traits, Gubiao 1,6,7 and 8 should be further iden-tified as top materials for tea breeding.%【目的】解剖、分析野生茶树叶片结构特征,为广西优质茶叶生产、种质资源鉴定和新品种选育提供参考依据。【方法】以广西扶绥9个野生茶树株系叶片为材料,采用改良石蜡切片方法制片、光学显微镜观察,分析和比较其抗逆性、潜在生产力、适制性和持嫩性等生产性状。【结果】9个野生茶树株系的叶片结构特征、丰产性状与制红茶

  17. Advances in remote sensing of vegetation function and traits

    KAUST Repository

    Houborg, Rasmus

    2015-07-09

    Remote sensing of vegetation function and traits has advanced significantly over the past half-century in the capacity to retrieve useful plant biochemical, physiological and structural quantities across a range of spatial and temporal scales. However, the translation of remote sensing signals into meaningful descriptors of vegetation function and traits is still associated with large uncertainties due to complex interactions between leaf, canopy, and atmospheric mediums, and significant challenges in the treatment of confounding factors in spectrum-trait relations. This editorial provides (1) a background on major advances in the remote sensing of vegetation, (2) a detailed timeline and description of relevant historical and planned satellite missions, and (3) an outline of remaining challenges, upcoming opportunities and key research objectives to be tackled. The introduction sets the stage for thirteen Special Issue papers here that focus on novel approaches for exploiting current and future advancements in remote sensor technologies. The described enhancements in spectral, spatial and temporal resolution and radiometric performance provide exciting opportunities to significantly advance the ability to accurately monitor and model the state and function of vegetation canopies at multiple scales on a timely basis.

  18. Complex bioclimatic and soil gradients shape leaf trait variation in Embothrium coccineum (Proteaceae among austral forests in Patagonia Gradientes bioclimáticos y edáficos modelan la variación en caracteres foliares de Embothrium coccineum (Proteaceae en los bosques australes de la Patagonia

    Directory of Open Access Journals (Sweden)

    CINTIA P SOUTO

    2009-06-01

    Full Text Available Patterns of trait variation may be adaptive when vary in relation to an environmental gradient. In particular, leaf traits can affect productivity and competitive ability. We identify patterns of leaf size and shape variation with environmental heterogeneity in one of the most widespread tree species within temperate South America: Embothrium coccineum (Proteaceae. We collected leaf specimens and composite soil samples from 35 populations between 38° and 55° S latitude in Patagonia, covering a wide range of mean annual precipitation (MAP and mean annual temperature (MAT. At each location, we measured nine morphological traits, some of which were cross correlated hence we focus on a smaller number of representative traits. We hypothesized that leaf area (LA, dry mass (DM, and specific leaf area (SLA would increase, and that leaf shape (SF would be more elongated, with increasing temperature, precipitation, and soil nutrient availability. We also expected growing season climate to be more closely associated with leaf traits than mean annual metrics. We used bivariate and backward stepwise multiple regressions to analyse the dependence of morphological traits with climatic and edaphic metrics. LA and DM increased with increasing summer rainfall or winter temperature, as hypothesized. Opposite to our hypothesis, LA and DM decreased with increasing summer temperature suggesting that in terms of leaf size, E. coccineum may sense summer conditions largely as an increasing aridity stressful gradient. Surprisingly, SLA increased with increasingly warm or dry summers. SF was related positively to MAT and negatively to MAP, suggesting that under more benign western climate regimes E. coccineum leaves tend to be elongated. Across sites, LA and DM increased with soil organic carbon and available phosphorus, and decreased with soil nitrogen and exchangeable cations. The opposite pattern was observed for SLA. Biologically meaningful climate metrics and soil

  19. Plant traits determine forest flammability

    Science.gov (United States)

    Zylstra, Philip; Bradstock, Ross

    2016-04-01

    Carbon and nutrient cycles in forest ecosystems are influenced by their inherent flammability - a property determined by the traits of the component plant species that form the fuel and influence the micro climate of a fire. In the absence of a model capable of explaining the complexity of such a system however, flammability is frequently represented by simple metrics such as surface fuel load. The implications of modelling fire - flammability feedbacks using surface fuel load were examined and compared to a biophysical, mechanistic model (Forest Flammability Model) that incorporates the influence of structural plant traits (e.g. crown shape and spacing) and leaf traits (e.g. thickness, dimensions and moisture). Fuels burn with values of combustibility modelled from leaf traits, transferring convective heat along vectors defined by flame angle and with plume temperatures that decrease with distance from the flame. Flames are re-calculated in one-second time-steps, with new leaves within the plant, neighbouring plants or higher strata ignited when the modelled time to ignition is reached, and other leaves extinguishing when their modelled flame duration is exceeded. The relative influence of surface fuels, vegetation structure and plant leaf traits were examined by comparing flame heights modelled using three treatments that successively added these components within the FFM. Validation was performed across a diverse range of eucalypt forests burnt under widely varying conditions during a forest fire in the Brindabella Ranges west of Canberra (ACT) in 2003. Flame heights ranged from 10 cm to more than 20 m, with an average of 4 m. When modelled from surface fuels alone, flame heights were on average 1.5m smaller than observed values, and were predicted within the error range 28% of the time. The addition of plant structure produced predicted flame heights that were on average 1.5m larger than observed, but were correct 53% of the time. The over-prediction in this

  20. Cedar leaf oil poisoning

    Science.gov (United States)

    Cedar leaf oil is made from some types of cedar trees. Cedar leaf oil poisoning occurs when someone swallows this substance. ... The substance in cedar leaf oil that can be harmful is thujone (a hydrocarbon).

  1. Quantitative trait loci for yield and morphological traits in maize under drought stress

    Directory of Open Access Journals (Sweden)

    Nikolić Ana

    2011-01-01

    Full Text Available Drought is one of the most important factors contributing to crop yield loss. In order to develop maize varieties with drought tolerance, it is necessary to explore the genetic basis. Mapping quantitative trait loci (QTL that control the yield and associate agronomic traits is one way of understanding drought genetics. QTLs associated with grain yield (GY, leaf width (LW3, LW4 plant height (PH, ear height (EH, leaf number (NL, tassel branch number (TBN and tassel length (TL were studied with composite interval mapping. A total of 43 QTLs were detected, distributed on all chromosomes, except chromosome 9. Phenotypic variability determined for the identified QTLs for all the traits was in the range from 20.99 to 87.24%. Mapping analysis identified genomic regions associated with two traits in a manner that was consistent with phenotypic correlation among traits, supporting either pleiotropy or tight linkage among QTLs.

  2. Leaf Collection Posting Log

    Data.gov (United States)

    Montgomery County of Maryland — This dataset contains leaf collection dates for area and subarea where leaf collection service is provided by Montgomery County Department of Transportation. Update...

  3. 灰绿藜叶特性对光照、营养和萌发时间的响应%Response of leaf traits of Chenopodium glaucum L. to light,nutrition,germination time

    Institute of Scientific and Technical Information of China (English)

    李勤; 黄迎新; 干友民

    2012-01-01

    @@%研究了不同光照、营养、萌发时间下灰绿藜的比叶面积(specific leaf area,SLA)和叶干物质含量(leaf dry matter content,LDMC)的变化.结果表明,除营养对LDMC外,不同条件对SLA和LDMC都影响显著(P<0.01);早萌发对灰绿藜生长更有利;与许多研究结果一样,低营养下SLA小,高营养下SLA大;叶片的SLA与LDMC之间呈显著负相关.

  4. QTL Analysis of Major Agronomic Traits in Soybean

    Institute of Scientific and Technical Information of China (English)

    CHEN Qing-shan; ZHANG Zhong-chen; LIU Chun-yan; XIN Da-wei; QIU Hong-mei; SHAN Da-peng; SHAN Cai-yun; HU Guo-hua

    2007-01-01

    Soybean is a main crop, and most agronomic traits of soybean are quantitative; therefore, there is very important studying and applying value to locating these traits. A F2:10 RIL population containing 154 lines, derived from the cross between Charleston as female and Dongnong 594 as male parent, were used in this experiment. A genetic linkage map was constructed with 164 SSR primers, which were screened with the two parents and amplified on the 154 lines. 12 agronomic traits different between the two parents were investigated, and QTLs of all the traits were analyzed using the software Windows QTL Cartographer V2.0. The agronomic traits included quality traits: protein content, oil content, and content of protein and oil; yield traits: pods per plant, seed weight per plant, arnd 100 seeds weight; and other agronomic traits: plant height, days to maturity, branches, nod number in main stem, average leaf length, and average leaf width. The results showed that 68 QTLs in total were found for the 12 agronomic traits. The number of QTLs per trait varied from 3 for the average leaf width to 11 for 100 seeds weight and plant height, and was 5.8 on average. Good accordance was seen in many QTLs between the results of this study and the results obtained by other similar studies; therefore, these QTLs may be valuable for molecular marker assistant selection in soybean. In this study, 68 major QTLs of 12 important traits of soybean were analyzed.

  5. Whitefly resistance traits derived from the wild tomato Solanum pimpinellifolium affect the preference and feeding behavior of Bemisia tabaci and reduce the spread of Tomato yellow leaf curl virus.

    Science.gov (United States)

    Rodríguez-López, M J; Garzo, E; Bonani, J P; Fereres, A; Fernández-Muñoz, R; Moriones, E

    2011-10-01

    Breeding of tomato genotypes that limit whitefly (Bemisia tabaci) access and feeding might reduce the spread of Tomato yellow leaf curl virus (TYLCV), a begomovirus (genus Begomovirus, family Geminiviridae) that is the causal agent of tomato yellow leaf curl disease. TYLCV is restricted to the phloem and is transmitted in a persistent manner by B. tabaci. The tomato breeding line ABL 14-8 was developed by introgressing type IV leaf glandular trichomes and secretion of acylsucroses from the wild tomato Solanum pimpinellifolium accession TO-937 into the genetic background of the whitefly- and virus-susceptible tomato cultivar Moneymaker. Results of preference bioassays with ABL 14-8 versus Moneymaker indicated that presence of type IV glandular trichomes and the production of acylsucrose deterred the landing and settling of B. tabaci on ABL 14-8. Moreover, electrical penetration graph studies indicated that B. tabaci adults spent more time in nonprobing activities and showed a reduced ability to start probing. Such behavior resulted in a reduced ability to reach the phloem. The superficial type of resistance observed in ABL 14-8 against B. tabaci probing significantly reduced primary and secondary spread of TYLCV.

  6. 施用保水剂对4种绿化植物叶片结构和功能性状的影响%Effects of Different Rate of Super Absorbent Polymer on Leaf Structural and Functional Traits of 4 Greening Plants

    Institute of Scientific and Technical Information of China (English)

    有祥亮; 沈烈英; 曹海东; 秦勇惠; 郗金标

    2014-01-01

    与CK相比,施用保水剂对‘紫花’海棠、乌桕、红叶石楠、梓树叶片的结构性状(叶面积、叶绿素含量、比叶面积、气孔导度)和功能性状(光合速率、蒸腾速率、水分利用效率)均有显著影响。4种供试植物在高温干旱环境下,0.1%用量保水剂能显著改善叶片结构和功能性状。而随保水剂用量的继续增加,4种植物的叶性状变化趋势并不一致,其中在0.2%保水剂用量下,红叶石楠和梓树叶面积、叶绿素含量、比叶面积、气孔导度、光合速率、蒸腾速率继续显著高于CK或0.1%用量,在0.3%用量下,2种植物上述指标大多接近于0.2%用量,而‘紫花’海棠和乌桕在0.2%~0.3%用量下已显著下降到接近CK水平。这表明,红叶石楠和梓树比‘紫花’海棠和乌桕较能适应水分较多的环境。而‘紫花’海棠和乌桕水分利用效率在CK条件下显著增大,则表明两者较能适应干旱环境。4种植物比叶面积在CK和不同保水剂用量下的显著变化表现出适宜水分条件下植物获取资源促进生长的能力和水分胁迫下的适应性。%This study was conducted to investigate effects of different rate of super absorbent polymer (SAP) on leaf structural and functional traits of 4 greening plants (i.e. Malus‘Purple’, Sapium sebiferum, Photinia × fraseri, Catalpa bignonioides). The results showed that the SAP had significant effect on the leaf structural traits (such as leaf area, chlorophyll content, specific leaf area and Gs) and functional traits (such as Pn, Tr and WUE) of Malus‘Purple’, Sapium sebiferum, Photinia × fraser and Catalpa bignonioides. 0.1% SAP content added to the soil could remarkably improve leaf structural and functional traits of the 4 greening plants. Applied with 0.2% SAP content, Photinia × fraser and Catalpa bignonioides had higher leaf area, chlorophyll content, specific leaf area, Gs, Pn and Tr than that of

  7. Effects of Different Tillage Methods on the Photosynthetic Traits of Maize Leaf%不同耕作方式对玉米叶片冠层光合特性的影响

    Institute of Scientific and Technical Information of China (English)

    刘武仁; 郑金玉; 罗洋; 郑洪兵; 李瑞平; 李伟堂; 李征; 胡庆生; 杨秀梅

    2012-01-01

    以郑单958为试验材料,在已经定位研究28年留茬深松(DT)、免耕(NT)、翻耕(PT)和传统耕法(CT)的基础上,探讨不同耕作方式对玉米叶片光合特性的影响.结果表明,不同耕作方式下玉米叶片的净光合速率(Pn)处理间存在差异,DT处理比NT、PT和CT分别高8.78%、25.50%和48.13%,NT处理比PT和CT分别高15.38%和16.00%,PT处理比CT高0.54%,DT和NT处理分别与CT差异达显著水平(p<0.05),其他处理间差异不显著(2010年);气孔导度(Gs)、胞间二氧化碳浓度(Ci)、蒸腾速率(Tr)和水分利用效率(WUE)处理间存在差异,差异不显著.%Zhengdan958 was chosen as experiment material, the impacts of long-term (28 years) deep tillage with high stubble, no-tillage, plow tillage and conventional tillage on maize photosynthesis were assessed. The test results showed that there were different leaf photosynthesis rates of maize among different tillage, leaf photosynthesis rates on deep tillage(DT) 8.78%, 25.50% and 48.13% higher than on on-tillage(NT), plow tillage(PT) and conventional tillage (CT). Similarly, leaf photosynthesis rates on NT were 15.38% higher than on PT and CT. Besides, leaf photosynthesis rates on plow tillage were 0.54% higher than on conventional tillage. However, Gs, Ci, Tr and WUE of maize leaf were different among tillage, but, there were not significant.

  8. Leaf phenology and its associated traits in the wintergreen species Aristotelia chilensis (Mol. Stuntz (Elaeocarpaceae Fenología foliar y sus caracteres asociados en la especie invierno-verde Aristotelia chilensis (Mol. Stuntz (Elaeocarpaceae

    Directory of Open Access Journals (Sweden)

    MARÍA ANGÉLICA DAMASCOS

    2001-12-01

    Full Text Available The post-summer leaf demography of the wintergreen species Aristotelia chilensis growing near San Carlos de Bariloche, Argentina, is described. Its specific leaf mass (SLM, g m-2 is compared to that of the deciduous and evergreen species of the Andean-Patagonian forests and to that of other communities abroad. The pattern of leaf emergence is intermediate, with leaf flush in spring (basal cohort, BC, followed by successive unfolding of the remaining leaves (distal cohort, DC during summer. The senescence of the BC occurs mainly in autumn, with a loss of 11-31 % of its SLM. The DC falls synchronously in mid-spring and the SLM loss in winter is 10-13 %. The SLM of A. chilensis (103.6 ± 6.2 g m-2 is intermediate when compared to the general mean values of deciduous (73.7 ± 15.9 g m-2 and evergreen species (154.8 ± 45.8 g m-2. The SLM of deciduous and evergreen species of three different forests near San Carlos de Bariloche varied significantly at the end of the growing season while that of A. chilensis showed more constant values. The periodicity of leaf production and senescence in A. chilensis allows the maintenance of one leaf cohort throughout the year, covering the carbon demand for flowering and leaf production in spring. This differentiates the deciduous from the wintergreen species, despite their similar mean leaf life span values, while the evergreen species have a longer leaf turnover. Considering the conditions for growth in each studied forest, the leaf life span was not the only factor determining the SLM value. This variable would also depend on multiple stresses that may act during the ontogenesis and evolution of the leaves in each phenological groupSe describe la demografía foliar después del verano de la especie invierno-verde Aristotelia chilensis, creciendo cerca de la ciudad de San Carlos de Bariloche, Argentina. Se compara su peso específico foliar (SLM, g m-2 con los valores de especies deciduas y siempreverdes de los

  9. Using plant functional traits to guide restoration: A case study in California coastal grassland

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Corbin, Jeffrey; Krupa, Monica

    2011-01-01

    ) amendments and (2) disturbance in the form of mowing. We measured height, specific leaf area, leaf thickness and leaf density from individuals of 39 species in the control and C addition plots, and supplemented these trait values with database information on growth form, lifespan, nitrogen-fixing ability...

  10. Linking leaf veins to growth and mortality rates: an example from a subtropical tree community.

    Science.gov (United States)

    Iida, Yoshiko; Sun, I-Fang; Price, Charles A; Chen, Chien-Teh; Chen, Zueng-Sang; Chiang, Jyh-Min; Huang, Chun-Lin; Swenson, Nathan G

    2016-09-01

    A fundamental goal in ecology is to link variation in species function to performance, but functional trait-performance investigations have had mixed success. This indicates that less commonly measured functional traits may more clearly elucidate trait-performance relationships. Despite the potential importance of leaf vein traits, which are expected to be related to resource delivery rates and photosynthetic capacity, there are few studies, which examine associations between these traits and demographic performance in communities. Here, we examined the associations between species traits including leaf venation traits and demographic rates (Relative Growth Rate, RGR and mortality) as well as the spatial distributions of traits along soil environment for 54 co-occurring species in a subtropical forest. Size-related changes in demographic rates were estimated using a hierarchical Bayesian approach. Next, Kendall's rank correlations were quantified between traits and estimated demographic rates at a given size and between traits and species-average soil environment. Species with denser venation, smaller areoles, less succulent, or thinner leaves showed higher RGR for a wide range of size classes. Species with leaves of denser veins, larger area, cheaper construction costs or thinner, or low-density wood were associated with high mortality rates only in small size classes. Lastly, contrary to our expectations, acquisitive traits were not related to resource-rich edaphic conditions. This study shows that leaf vein traits are weakly, but significantly related to tree demographic performance together with other species traits. Because leaf traits associated with an acquisitive strategy such as denser venation, less succulence, and thinner leaves showed higher growth rate, but similar leaf traits were not associated with mortality, different pathways may shape species growth and survival. This study suggests that we are still not measuring some of key traits related to

  11. Do general patterns of leaf thermoregulation hold in the tropics?

    Science.gov (United States)

    Michaletz, S. T.; Blonder, B.; Chambers, J.; Enquist, B. J.; Faybishenko, B.; Grossiord, C.; Jardine, K.; Negron Juarez, R. I.; Varadharajan, C.; McDowell, N. G.; Detto, M.; Wolfe, B.

    2016-12-01

    Leaf temperature is a critical driver of plant and ecosystem functioning because it governs rates of photosynthesis and transpiration. While leaf temperatures are often assumed to equal ambient air temperatures, recent studies show that leaves thermoregulate, so they are warmer than air in cool temperatures and cooler than air in warm temperatures. This pattern appears to be general across diverse plant taxa and boreal-to-subtropical air temperature gradients. However, one exception to the general pattern may be the tropics, where scant data suggest that daytime leaf temperatures are always warmer and increase at a faster rate than air temperature, possibly because transpiration and latent heat fluxes are limited by high relative humidity. In this talk, we evaluate tropical leaf thermoregulation using new data from the DOE Next Generation Ecosystem Experiments-Tropics project and a recent analytical energy budget model for leaf temperature. The model expresses leaf temperature as a linear function of air temperature, several additional meteorological variables, and several leaf functional traits. We examine patterns of tropical leaf thermoregulation and identify the relative importance of meteorological variables and leaf traits in driving these patterns. Our results demonstrate that the temperatures of plant tissues, and not just air, are vital to developing more accurate earth system models.

  12. Altitudinal variation of leaf traits of Quercus baronii in Yunqiu Mountain%云丘山不同海拔梯度橿子栎叶性特征研究

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    在吕梁山南段云丘山,以橿子栎为主要研究对象,采用野外调查和室内实验相结合的方法,对比叶面积(SLA)、叶面积(LA)、叶干物质含量(LDMC)、叶长宽比(L/W)、叶绿素含量(Chl)以及叶氮含量等有代表性的指标进行分析.结果表明:(1)随着海拔梯度的增加,橿子栎 L/W、Chl、SLA、LA、单位面积的叶氮含量(N area )、单位重量的叶氮含量(N mass )、叶饱和鲜重和叶干重均呈先上升后下降的趋势,在海拔1180 m 处有最大值;LDMC 与海拔呈显著负相关(P <0.05);(2)橿子栎 LA 与 SLA 和 N mass 呈极显著正相关关系(P <0.01),与 LDMC 呈显著负相关关系(P <0.05),与 N area呈极显著负相关关系(P <0.01);(3)橿子栎叶片 SLA与 L/W 呈显著正相关(P <0.05),与 N mass 呈极显著正相关关系(P <0.01),橿子栎叶片 SLA 与 LDMC 和N area呈显著负相关关系(P <0.05);(4)橿子栎 LDMC 与 N area 呈显著正相关(P <0.05).通过对云丘山景区橿子栎叶片性状随海拔变化规律的研究,可以探索橿子栎叶片性状与海拔梯度变化的关系以及最适生长环境,从而为景区橿子栎林的保护和抚育提供理论依据,为合理开发橿子栎林资源提供基础资料.%Combining field investigation and indoor experiments of Quercus baronii in Yunqiu scenic spot of south Lüliang Mountain,some representative indicators such as specific leaf area (SLA),leaf area (LA),leaf dry matter content (LDMC),leaf aspect ratio (L/W),chlorophyll content (Chl),and leaf nitrogen content were performed and analyzed.The results were as follows:(1)As elevation gradient rises up,Q.baronii aspect ratio,Chlorophyll,SLA, LA,N area ,N mas ,saturated fresh and dry weight,all of their indicators had a first-increase-and-then-decrease trend and their peak value appeared at the altitude of 1 180 m;however,LDMC had a significant negative correlation (P <0.05) with the

  13. Ecological Impact of Climate Change on Leaf Economic Strategies Across the Paleocene- Eocene Thermal Maximum, Bighorn Basin, Wyoming

    Science.gov (United States)

    Royer, D. L.; Currano, E. D.; Wilf, P.; Wing, S. L.; Labandeira, C. C.; Lovelock, E. C.

    2007-12-01

    Deciphering the ecological impacts of climate change is a key priority for paleontologists and ecologists alike. An important ecological metric in vegetated settings is the leaf economics spectrum, which represents an adaptive continuum running from rapid resource acquisition to maximized resource retention. This spectrum is comprised of a large number of coordinated traits, including leaf mass per area (LMA), leaf lifespan, photosynthetic rate, nutrient concentration, and palatability to herbivores. Here we apply a recently developed technique for reconstructing LMA to a suite of four isotaphonomic fossil plant sites spanning the Paleocene-Eocene thermal maximum (PETM) in the Bighorn Basin, Wyoming, USA. This technique is based on the biomechanical scaling between petiole width and leaf mass, and it has been calibrated with 65 present-day sites from five continents and tested on two well-known Eocene fossil localities (Bonanza, Utah and Republic, Washington). There are no significant differences in LMA among plants across the PETM. This stasis is present despite a backdrop of extreme climate change during the PETM in this region, including a three-to-four-fold increase in atmospheric CO2, an ~5 °C rise in temperature, and possible drying. Moreover, quantitative measurements of insect herbivory show, on average, a two-fold increase during the PETM relative to before and after the event. We interpret our results to suggest that leaf-economic relationships can, in some situations, partially decouple. More specifically, our documented increase in insect herbivory during the PETM with no concomitant decrease in LMA implies that during this interval less carbon was being captured by plants per unit of investment. Because the rate and magnitude of climate change during the PETM is similar to present-day anthropogenic changes, our results may provide clues for predictions of ecological impacts in the near future.

  14. Linking hydraulic traits to tropical forest function in a size-structured and trait-driven model (TFS v.1-Hydro)

    Science.gov (United States)

    Christoffersen, Bradley O.; Gloor, Manuel; Fauset, Sophie; Fyllas, Nikolaos M.; Galbraith, David R.; Baker, Timothy R.; Kruijt, Bart; Rowland, Lucy; Fisher, Rosie A.; Binks, Oliver J.; Sevanto, Sanna; Xu, Chonggang; Jansen, Steven; Choat, Brendan; Mencuccini, Maurizio; McDowell, Nate G.; Meir, Patrick

    2016-11-01

    Forest ecosystem models based on heuristic water stress functions poorly predict tropical forest response to drought partly because they do not capture the diversity of hydraulic traits (including variation in tree size) observed in tropical forests. We developed a continuous porous media approach to modeling plant hydraulics in which all parameters of the constitutive equations are biologically interpretable and measurable plant hydraulic traits (e.g., turgor loss point πtlp, bulk elastic modulus ɛ, hydraulic capacitance Cft, xylem hydraulic conductivity ks,max, water potential at 50 % loss of conductivity for both xylem (P50,x) and stomata (P50,gs), and the leaf : sapwood area ratio Al : As). We embedded this plant hydraulics model within a trait forest simulator (TFS) that models light environments of individual trees and their upper boundary conditions (transpiration), as well as providing a means for parameterizing variation in hydraulic traits among individuals. We synthesized literature and existing databases to parameterize all hydraulic traits as a function of stem and leaf traits, including wood density (WD), leaf mass per area (LMA), and photosynthetic capacity (Amax), and evaluated the coupled model (called TFS v.1-Hydro) predictions, against observed diurnal and seasonal variability in stem and leaf water potential as well as stand-scaled sap flux. Our hydraulic trait synthesis revealed coordination among leaf and xylem hydraulic traits and statistically significant relationships of most hydraulic traits with more easily measured plant traits. Using the most informative empirical trait-trait relationships derived from this synthesis, TFS v.1-Hydro successfully captured individual variation in leaf and stem water potential due to increasing tree size and light environment, with model representation of hydraulic architecture and plant traits exerting primary and secondary controls, respectively, on the fidelity of model predictions. The plant

  15. Genetic control of the leaf angle and leaf orientation value as revealed by ultra-high density maps in three connected maize populations.

    Directory of Open Access Journals (Sweden)

    Chunhui Li

    Full Text Available Plant architecture is a key factor for high productivity maize because ideal plant architecture with an erect leaf angle and optimum leaf orientation value allow for more efficient light capture during photosynthesis and better wind circulation under dense planting conditions. To extend our understanding of the genetic mechanisms involved in leaf-related traits, three connected recombination inbred line (RIL populations including 538 RILs were genotyped by genotyping-by-sequencing (GBS method and phenotyped for the leaf angle and related traits in six environments. We conducted single population quantitative trait locus (QTL mapping and joint linkage analysis based on high-density recombination bin maps constructed from GBS genotype data. A total of 45 QTLs with phenotypic effects ranging from 1.2% to 29.2% were detected for four leaf architecture traits by using joint linkage mapping across the three populations. All the QTLs identified for each trait could explain approximately 60% of the phenotypic variance. Four QTLs were located on small genomic regions where candidate genes were found. Genomic predictions from a genomic best linear unbiased prediction (GBLUP model explained 45±9% to 68±8% of the variation in the remaining RILs for the four traits. These results extend our understanding of the genetics of leaf traits and can be used in genomic prediction to accelerate plant architecture improvement.

  16. Evolutionary Position and Leaf Toughness Control Chemical Transformation of Litter, and Drought Reinforces This Control: Evidence from a Common Garden Experiment across 48 Species

    OpenAIRE

    Xu Pan; Yao-Bin Song; Can Jiang; Guo-Fang Liu; Xue-Hua Ye; Xiu-Fang Xie; Yu-Kun Hu; Wei-Wei Zhao; Lijuan Cui; Johannes H. C. Cornelissen; Ming Dong; Andreas Prinzing

    2015-01-01

    Plant leaf litter is an important source of soil chemicals that are essential for the ecosystem and changes in leaf litter chemical traits during decomposition will determine the availability of multiple chemical elements recycling in the ecosystem. However, it is unclear whether the changes in litter chemical traits during decomposition and their similarities across species can be predicted, respectively, using other leaf traits or using the phylogenetic relatedness of the litter species. He...

  17. Global Climatic Controls On Leaf Size

    Science.gov (United States)

    Wright, I. J.; Prentice, I. C.; Dong, N.; Maire, V.

    2015-12-01

    Since the 1890s it's been known that the wet tropics harbour plants with exceptionally large leaves. Yet the observed latitudinal gradient of leaf size has never been fully explained: it is still unclear which aspects of climate are most important for understanding geographic trends in leaf size, a trait that varies many thousand-fold among species. The key is the leaf-to-air temperature difference, which depends on the balance of energy inputs (irradiance) and outputs (transpirational cooling, losses to the night sky). Smaller leaves track air temperatures more closely than larger leaves. Widely cited optimality-based theories predict an advantage for smaller leaves in dry environments, where transpiration is restricted, but are silent on the latitudinal gradient. We aimed to characterize and explain the worldwide pattern of leaf size. Across 7900 species from 651 sites, here we show that: large-leaved species predominate in wet, hot, sunny environments; smaller-leaved species typify hot, sunny environments only when arid; small leaves are required to avoid freezing in high latitudes and at high elevation, and to avoid overheating in dry environments. This simple pattern was unclear in earlier, more limited analyses. We present a simple but robust, fresh approach to energy-balance modelling for both day-time and night-time leaf-to-air temperature differences, and thus risk of overheating and of frost damage. Our analysis shows night-chilling is important as well as day-heating, and simplifies leaf temperature modelling. It provides both a framework for modelling leaf size constraints, and a solution to one of the oldest conundrums in ecology. Although the path forward is not yet fully clear, because of its role in controlling leaf temperatures we suggest that climate-related leaf size constraints could usefully feature in the next generation of land ecosystem models.

  18. Apparent over-investment in leaf venation relaxes leaf morphological constraints on photosynthesis in arid habitats

    Science.gov (United States)

    de Boer, Hugo; Drake, Paul; Veneklaas, Erik

    2017-04-01

    The close relationship between leaf water status and stomatal conductance implies that the hydraulic architecture of leaves poses an important constraint on transpiration, specifically in arid environments with high evaporative demands. However, it remains uncertain how morphological, hydraulic and photosynthetic traits are coordinated to achieve optimal leaf functioning in arid environments. Critical is that leaf veins supply the mesophyll with water that evaporates when stomata are open to allow CO2 uptake for photosynthesis. Theoretical analyses suggest that water is optimally distributed in the mesophyll when the lateral distance between veins (dx) is equal to the distance from these veins to the epidermis (dy), expressed as dx:dy≈1. Although this theory is supported by observations on many derived angiosperms, we hypothesize that plants in arid environments may reduce dx:dy below unity owing to climate-specific functional adaptations of increased leaf thickness and increased vein density. To test our hypothesis we assembled leaf hydraulic, morphological and photosynthetic traits of 68 species from the Eucalyptus and Corymbia genera (termed eucalypts) along an aridity gradient in southwestern Australia. We inferred the potential gas exchange advantage of reducing dx beyond dy using a model that links leaf morphology and hydraulics to photosynthesis. Our observations reveal that eucalypts in arid environments have thick amphistomatous leaves with high vein densities, resulting in dx:dy ratios that range from 1.6 to 0.15 along the aridity gradient. Our model suggests that as leaves become thicker, the effect of reducing dx beyond dy is to offset the reduction in leaf gas exchange that would result from maintaining dx:dy at unity. This apparent over-investment in leaf venation may be explained from the selective pressure of aridity, under which traits associated with long leaf lifespan, high hydraulic and thermal capacitances, and high potential rates of leaf

  19. Multivariate identification of plant functional response and effect traits in an agricultural landscape.

    Science.gov (United States)

    Pakeman, Robin J

    2011-06-01

    Plant functional traits have been proposed as a linkage between the environmental control of vegetation and ecosystem function. Identification of traits that mediate the response of plant species to the environment is well established, but the identification of effect traits and the linkage between the two sets is less developed. This was attempted for a study of eight contrasting land uses in a marginal agricultural landscape where data on vegetation, management controls of the disturbance regime, and soil characteristics, including nitrogen release, were measured simultaneously with measures of ecosystem function such as litter decomposition rates and primary productivity on 30 sites. Trait data were assembled from databases, and an iterative multivariate approach using the three table (species, trait, environment) method RLQ was employed to identify a parsimonious set of traits that predict plant species responses to the environment and a parsimonious set of traits that link vegetation to ecosystem function. The lists of response and effect traits were similar, and where differences were observed, traits were usually highly correlated with at least one trait in the other list. This approach identified a small number of traits (canopy height, leaf dry matter content, leaf size, and specific leaf area) that provide a means of linking vegetation responses to environmental change with changes in ecosystem function. Other response traits included vegetative spread strategy, start of flowering, and seed terminal velocity, but within the system studied these traits were all significantly correlated to the traits shared between the response and effect lists.

  20. Leaf function in tropical rain forest canopy trees: the effect of light on leaf morphology and physiology in different-sized trees

    NARCIS (Netherlands)

    Rijkers, T.

    2000-01-01

    In this thesis the effect of constant and fluctuating light availability on several leaf traits was studied for naturally growing trees of different sizes, i.e . from sapling to adult canopy tree, of five species in a tropical rain forest in French Guiana. Leaf acclimation responses were examined th

  1. Leaf traits and tree rings suggest different water-use and carbon assimilation strategies by two co-occurring Quercus species in a Mediterranean mixed-forest stand in Tuscany, Italy.

    Science.gov (United States)

    Tognetti, Roberto; Cherubini, Paolo; Marchi, Susanna; Raschi, Antonio

    2007-12-01

    We compared the water-use characteristics of co-occurring mature Quercus cerris L. and Quercus pubescens Willd. trees growing in resource-limited (mainly water) hilly habitats in Tuscany, Italy. The species differed in their distribution along soil water gradients and in their access to, and use of, water, even though the study year was wetter than average, though with a summer drought. Compared with Q. cerris, Q. pubescens had greater access to soil water (less negative predawn water potentials) and a more conservative water-use strategy based on its relatively low stomatal conductance, high instantaneous water-use efficiency, less negative midday water potential and high soil-to-leaf hydraulic conductance. Quercus cerris had less conservative water-use characteristics than Q. pubescens, exhibiting relatively high stomatal conductance, low instantaneous water-use efficiency, more negative midday water potentials and low soil-to-leaf hydraulic conductance; however, Q. cerris had higher photosynthetic rates than Q. pubescens. Photosynthesis and stomatal conductance were positively correlated in both species. Although a strong correlation between ring widths and precipitation patterns was not found, some dry periods influenced ring-width growth. Quercus pubescens has always grown faster than Q. cerris, probably because of more efficient water use, although stand dynamics (driven by exogenous disturbance factors, including coppicing, browsing and competition) cannot be excluded. Ring-width variability, as well as tree-ring growth in dry years, which should be unaffected by stand dynamics, were higher in Q. pubescens than in Q. cerris. Moreover, Q. pubescens recovered completely after the drought in the seventies, even showing higher tree-ring growth than in the recent past, whereas Q. cerris showed a minor growth decline followed by a recovery to values comparable with those observed before the 1970s drought. Beginning in the early eighties, tree-ring growth decreased

  2. Intraspecific trait variation drives functional responses of old-field plant communities to nutrient enrichment.

    Science.gov (United States)

    Siefert, Andrew; Ritchie, Mark E

    2016-05-01

    Environmental changes are expected to shift the distribution of functional trait values in plant communities through a combination of species turnover and intraspecific variation. The strength of these shifts may depend on the availability of individuals with trait values adapted to new environmental conditions, represented by the functional diversity (FD) of existing community residents or dispersal from the regional species pool. We conducted a 3-year nutrient- and seed-addition experiment in old-field plant communities to examine the contributions of species turnover and intraspecific variation to community trait shifts, focusing on four key plant functional traits: vegetative height, leaf area, specific leaf area (SLA), and leaf dry matter content (LDMC). We further examined the influence of initial FD and seed availability on the strength of these shifts. Community mean height, leaf area, and SLA increased in response to fertilization, and these shifts were driven almost entirely by intraspecific variation. The strength of intraspecific shifts in height and leaf area was positively related to initial intraspecific FD in these traits. Intraspecific trait responses to fertilization varied among species, with species of short stature displaying stronger shifts in SLA and LDMC but weaker shifts in leaf area. Trait shifts due to species turnover were generally weak and opposed intraspecific responses. Seed addition altered community taxonomic composition but had little effect on community trait shifts. These results highlight the importance of intraspecific variation for short-term community functional responses and demonstrate that the strength of these responses may be mediated by community FD.

  3. Variations of leaf N, P concentrations in shrubland biomes across northern China: phylogeny, climate and soil

    Directory of Open Access Journals (Sweden)

    X. Yang

    2015-11-01

    Full Text Available Concentrations of leaf nitrogen (N and phosphorus (P are key leaf traits in ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on trees and grasses, leaving the knowledge gap for the stoichiometric patterns of shrubs. In this study, we explored the intra- and interspecific variations of leaf N and P concentration in relation to climate, soil property and evolutionary history based on 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China expanding 46.1° (86.7–132.8° E in longitude and 19.8° (32.6–52.4° N in latitude. The results showed that leaf N concentration decreased with precipitation, leaf P concentration decreased with temperature and increased with precipitation and soil P concentration. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentration was less conserved than leaf N concentration. At community level, climates explained more interspecific, while soil nutrient explained more intraspecific, variation of leaf nutrient concentrations. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits.

  4. Variations of leaf N, P concentrations in shrubland biomes across northern China: phylogeny, climate and soil

    Science.gov (United States)

    Yang, X.; Chi, X.; Ji, C.; Liu, H.; Ma, W.; Mohhammat, A.; Shi, Z.; Wang, X.; Yu, S.; Yue, M.; Tang, Z.

    2015-11-01

    Concentrations of leaf nitrogen (N) and phosphorus (P) are key leaf traits in ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on trees and grasses, leaving the knowledge gap for the stoichiometric patterns of shrubs. In this study, we explored the intra- and interspecific variations of leaf N and P concentration in relation to climate, soil property and evolutionary history based on 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China expanding 46.1° (86.7-132.8° E) in longitude and 19.8° (32.6-52.4° N) in latitude. The results showed that leaf N concentration decreased with precipitation, leaf P concentration decreased with temperature and increased with precipitation and soil P concentration. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentration was less conserved than leaf N concentration. At community level, climates explained more interspecific, while soil nutrient explained more intraspecific, variation of leaf nutrient concentrations. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits.

  5. Quantitative trait locus analysis of multiple agronomic traits in the model legume Lotus japonicus.

    Science.gov (United States)

    Gondo, Takahiro; Sato, Shusei; Okumura, Kenji; Tabata, Satoshi; Akashi, Ryo; Isobe, Sachiko

    2007-07-01

    The first quantitative trait locus (QTL) analysis of multiple agronomic traits in the model legume Lotus japonicus was performed with a population of recombinant inbred lines derived from Miyakojima MG-20 x Gifu B-129. Thirteen agronomic traits were evaluated in 2004 and 2005: traits of vegetative parts (plant height, stem thickness, leaf length, leaf width, plant regrowth, plant shape, and stem color), flowering traits (flowering time and degree), and pod and seed traits (pod length, pod width, seeds per pod, and seed mass). A total of 40 QTLs were detected that explained 5%-69% of total variation. The QTL that explained the most variation was that for stem color, which was detected in the same region of chromosome 2 in both years. Some QTLs were colocated, especially those for pod and seed traits. Seed mass QTLs were located at 5 locations that mapped to the corresponding genomic positions of equivalent QTLs in soybean, pea, chickpea, and mung bean. This study provides fundamental information for breeding of agronomically important legume crops.

  6. Evaluating the Importance of Plant Functional Traits: the Subalpine and Alpine

    Science.gov (United States)

    Sanchez, A.; Smith, W. K.

    2011-12-01

    Over the past several decades, researchers have attempted to characterize plant groups according to traits that are considered functional, i.e. contributing significantly to fitness. Due to the complexity of measuring fitness, the capability for photosynthetic carbon gain is often used as a proxy. Thus, this approach correlates structural differences to photosynthetic performance, especially those differences that are known to be associated with photosynthesis, are easily measured and inexpensive. At the often sharp boundary between the subalpine forest and alpine community (treeline ecotone), plant structural traits change dramatically, i.e. tall evergreen trees give way abruptly to low-stature shrubs, grasses, forbs, and herbs. Yet, the differences in functional traits, so abundant in the literature for a variety of species and communities, have not been compared contiguous communities such as the subalpine forest and alpine. Can differences in functional traits already identified in the literature also be used to characterize species of these two contrasting communities? Or are there other traits that are most functional and/or, possibly, unique to each community and not the most popular traits reported so far in the literature. Also, does the community structure itself help determine functional traits? For example, the top ten most frequently studied traits (145 total papers from approximately 63 different refereed journals) considered functional include the following (% of the 145 publications): specific leaf area or mass (SLA or SLM 39%), plant height (36%), leaf nitrogen content (34%), leaf size (19%), leaf area (16%), leaf photosynthetic performance (15%), leaf dry matter content (LDMC 15%), leaf mass per unit leaf area (LMA 15%), leaf thickness (15%), and seed mass (14%). In addition, another 120 traits were mentioned as functional, although all fell below a 14% citation rate. Particular focus was placed on this group due to the possibility that they might

  7. Co-ordination in morphological leaf traits of early diverging angiosperms is maintained following exposure to experimental palaeo-atmospheric conditions of sub-ambient O2 and elevated CO2

    Directory of Open Access Journals (Sweden)

    Christiana Evans-Fitz.Gerald

    2016-09-01

    Full Text Available In order to be successful in a given environment a plant should invest in a vein network and stomatal distribution that ensures balance between both water supply and demand. Vein density (Dv and stomatal density (SD have been shown to be strongly positively correlated in response to a range of environmental variables in more recently evolved plant species, but the extent of this relationship has not been confirmed in earlier diverging plant lineages. In order to examine the effect of a changing atmosphere on the relationship between Dv and SD, five early-diverging plant species representing two different reproductive plant grades were grown for seven months in a palaeo-treatment comprising an O2:CO2 ratio that has occurred multiple times throughout plant evolutionary history. Results show a range of species-specific Dv and SD responses to the palaeo-treatment, however we show that the strong relationship between Dv and SD under modern ambient atmospheric composition is maintained following exposure to the palaeo-treatment. This suggests strong inter-specific co-ordination between vein and stomatal traits for our study species even under relatively extreme environmental change. This co-ordination supports existing plant function proxies that use the distance between vein endings and stomata (Dm to infer plant palaeo-physiology.

  8. Co-ordination in Morphological Leaf Traits of Early Diverging Angiosperms Is Maintained Following Exposure to Experimental Palaeo-atmospheric Conditions of Sub-ambient O2 and Elevated CO2

    Science.gov (United States)

    Evans-Fitz.Gerald, Christiana; Porter, Amanda S.; Yiotis, Charilaos; Elliott-Kingston, Caroline; McElwain, Jennifer C.

    2016-01-01

    In order to be successful in a given environment a plant should invest in a vein network and stomatal distribution that ensures balance between both water supply and demand. Vein density (Dv) and stomatal density (SD) have been shown to be strongly positively correlated in response to a range of environmental variables in more recently evolved plant species, but the extent of this relationship has not been confirmed in earlier diverging plant lineages. In order to examine the effect of a changing atmosphere on the relationship between Dv and SD, five early-diverging plant species representing two different reproductive plant grades were grown for 7 months in a palaeo-treatment comprising an O2:CO2 ratio that has occurred multiple times throughout plant evolutionary history. Results show a range of species-specific Dv and SD responses to the palaeo-treatment, however, we show that the strong relationship between Dv and SD under modern ambient atmospheric composition is maintained following exposure to the palaeo-treatment. This suggests strong inter-specific co-ordination between vein and stomatal traits for our study species even under relatively extreme environmental change. This co-ordination supports existing plant function proxies that use the distance between vein endings and stomata (Dm) to infer plant palaeo-physiology. PMID:27695464

  9. Palm Functional Traits: which traits matter and how do we measure them?

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Balslev, Henrik; Barfod, Anders S.

    role of palms in tropical forest ecosystems. We review data availability for palms for four traits that are commonly used in functional plant ecology: specific leaf area (SLA), wood density, seed size, and maximum height. We suggest that palm functional ecology is impeded by some of the standard...... allow capturing leaf economics across large parts of the palm family with reasonable amounts of time and money....... functional traits being difficult to measure (e.g. SLA) or interpret (e.g. wood density). We show that an SLA measure can be easily obtained from dried specimens, and discuss the problems and opportunities of this approach compared to whole-leaf SLA measurements. Measuring SLA from herbarium samples may...

  10. Paleotemperature proxies from leaf fossils reinterpreted in light of evolutionary history.

    Directory of Open Access Journals (Sweden)

    Stefan A Little

    Full Text Available Present-day correlations between leaf physiognomic traits (shape and size and climate are widely used to estimate paleoclimate using fossil floras. For example, leaf-margin analysis estimates paleotemperature using the modern relation of mean annual temperature (MAT and the site-proportion of untoothed-leaf species (NT. This uniformitarian approach should provide accurate paleoclimate reconstructions under the core assumption that leaf-trait variation principally results from adaptive environmental convergence, and because variation is thus largely independent of phylogeny it should be constant through geologic time. Although much research acknowledges and investigates possible pitfalls in paleoclimate estimation based on leaf physiognomy, the core assumption has never been explicitly tested in a phylogenetic comparative framework. Combining an extant dataset of 21 leaf traits and temperature with a phylogenetic hypothesis for 569 species-site pairs at 17 sites, we found varying amounts of non-random phylogenetic signal in all traits. Phylogenetic vs. standard regressions generally support prevailing ideas that leaf-traits are adaptively responding to temperature, but wider confidence intervals, and shifts in slope and intercept, indicate an overall reduced ability to predict climate precisely due to the non-random phylogenetic signal. Notably, the modern-day relation of proportion of untoothed taxa with mean annual temperature (NT-MAT, central in paleotemperature inference, was greatly modified and reduced, indicating that the modern correlation primarily results from biogeographic history. Importantly, some tooth traits, such as number of teeth, had similar or steeper slopes after taking phylogeny into account, suggesting that leaf teeth display a pattern of exaptive evolution in higher latitudes. This study shows that the assumption of convergence required for precise, quantitative temperature estimates using present-day leaf traits is not

  11. Using plant functional traits to guide restoration: A case study in California coastal grassland

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Corbin, Jeffrey; Krupa, Monica

    2011-01-01

    ) amendments and (2) disturbance in the form of mowing. We measured height, specific leaf area, leaf thickness and leaf density from individuals of 39 species in the control and C addition plots, and supplemented these trait values with database information on growth form, lifespan, nitrogen-fixing ability...... and seed mass.   Consistent with theoretical predictions, C addition favored short, large-seeded and nitrogen-fixing species, while mowing benefitted short species with high specific leaf area. However, native and exotic species did not differ in any of the measured traits, and neither group benefitted...

  12. Contrasting effects of intraspecific trait variation on trait-based niches and performance of legumes in plant mixtures.

    Directory of Open Access Journals (Sweden)

    Christiane Roscher

    Full Text Available Niche differentiation, assumed to be a key mechanism of species coexistence, requires that species differ in their functional traits. So far it remains unclear to which extent trait plasticity leads to niche shifts of species at higher plant diversity, thereby increasing or decreasing niche overlap between species. To analyse this question it is convenient to measure niches indirectly via the variation in resource-uptake traits rather than directly via the resources used. We provisionally call these indirectly measured niches trait-based niches. We studied shoot- and leaf-morphological characteristics in seven legume species in monoculture and multi-species mixture in experimental grassland. Legume species varied in the extent of trait variation in response to plant diversity. Trait plasticity led to significant shifts in species niches in multiple dimensions. Single-species niches in several traits associated with height growth and filling of canopy space were expanded, while other niche dimensions were compressed or did not change with plant diversity. Niche separation among legumes decreased in dimensions related to height growth and space filling, but increased in dimensions related to leaf size and morphology. The total extent of occupied niche space was larger in mixture than in the combined monocultures for dimensions related to leaf morphology and smaller for dimensions related to whole-plant architecture. Taller growth, greater space filling and greater plasticity in shoot height were positively, while larger values and greater plasticity in specific leaf area were negatively related with increased performance of species in mixture. Our study shows that trait variation in response to plant diversity shifts species niches along trait axes. Plastically increased niche differentiation is restricted to niche dimensions that are apparently not related to size-dependent differences between species, but functional equivalence (convergence in

  13. Contrasting effects of intraspecific trait variation on trait-based niches and performance of legumes in plant mixtures.

    Science.gov (United States)

    Roscher, Christiane; Schumacher, Jens; Schmid, Bernhard; Schulze, Ernst-Detlef

    2015-01-01

    Niche differentiation, assumed to be a key mechanism of species coexistence, requires that species differ in their functional traits. So far it remains unclear to which extent trait plasticity leads to niche shifts of species at higher plant diversity, thereby increasing or decreasing niche overlap between species. To analyse this question it is convenient to measure niches indirectly via the variation in resource-uptake traits rather than directly via the resources used. We provisionally call these indirectly measured niches trait-based niches. We studied shoot- and leaf-morphological characteristics in seven legume species in monoculture and multi-species mixture in experimental grassland. Legume species varied in the extent of trait variation in response to plant diversity. Trait plasticity led to significant shifts in species niches in multiple dimensions. Single-species niches in several traits associated with height growth and filling of canopy space were expanded, while other niche dimensions were compressed or did not change with plant diversity. Niche separation among legumes decreased in dimensions related to height growth and space filling, but increased in dimensions related to leaf size and morphology. The total extent of occupied niche space was larger in mixture than in the combined monocultures for dimensions related to leaf morphology and smaller for dimensions related to whole-plant architecture. Taller growth, greater space filling and greater plasticity in shoot height were positively, while larger values and greater plasticity in specific leaf area were negatively related with increased performance of species in mixture. Our study shows that trait variation in response to plant diversity shifts species niches along trait axes. Plastically increased niche differentiation is restricted to niche dimensions that are apparently not related to size-dependent differences between species, but functional equivalence (convergence in height growth) rather

  14. Leaf thickness controls variation in leaf mass per area (LMA) among grazing-adapted grasses in Serengeti.

    Science.gov (United States)

    Griffith, Daniel M; Quigley, Kathleen M; Anderson, T Michael

    2016-08-01

    Leaf mass per area (LMA) is a primary plant functional trait that represents the cost of constructing a leaf. Ultimately, plants modify LMA by altering leaf thickness (LT), leaf dry matter content (LDMC), or both. While LMA can be modified through both of these constituents, studies of LMA have found that there is variation in whether LT or LDMC changes are responsible for LMA-and the relationships change depending on the species or functional groups being compared. In this study, we used a phylogenetic framework to determine that evolutionary shifts in LMA are driven by LT, and not LDMC, among 45 Serengeti grass species. We considered two alternative hypotheses that could result in evolutionary correlation of LMA on LT but not LDMC: either (1) LT is more labile than LDMC-and is therefore a less costly means to change LMA or (2) LDMC is tightly coupled to a different dimension of leaf variation (e.g., leaf hydraulics), leaving LT as the source of variation in LMA. LT was not more labile than LDMC, leading us to conclude that the evolution of LMA has been shaped by LT because LDMC is responding to other demands on leaf physiology. We speculate that leaf hydraulics provide this constraint on LDMC. The decoupling of LDMC from LT may allow plants to better optimize resource allocation in ecosystems where gradients in light competition, herbivory, and aridity place competing demands on leaf economics.

  15. Taxonomy and remote sensing of leaf mass per area (LMA) in humid tropical forests

    Science.gov (United States)

    Gregory P. Asner; Roberta E. Martin; Raul Tupayachi; Ruth Emerson; Paola Martinez; Felipe Sinca; George V.N. Powell; S. Joseph Wright; Ariel E. Lugo

    2011-01-01

    Leaf mass per area (LMA) is a trait of central importance to plant physiology and ecosystem function, but LMA patterns in the upper canopies of humid tropical forests have proved elusive due to tall species and high diversity. We collected top-of-canopy leaf samples from 2873 individuals in 57 sites spread across the Neotropics, Australasia, and Caribbean and Pacific...

  16. Plant trait-species abundance relationships vary with environmental properties in subtropical forests in eastern china.

    Directory of Open Access Journals (Sweden)

    En-Rong Yan

    Full Text Available Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N and phosphorus (P contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA, leaf N concentration (LN, and total leaf area per twig size (TLA were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests.

  17. Variations of leaf N and P concentrations in shrubland biomes across northern China: phylogeny, climate, and soil

    Science.gov (United States)

    Yang, Xian; Chi, Xiulian; Ji, Chengjun; Liu, Hongyan; Ma, Wenhong; Mohhammat, Anwar; Shi, Zhaoyong; Wang, Xiangping; Yu, Shunli; Yue, Ming; Tang, Zhiyao

    2016-08-01

    Concentrations of leaf nitrogen (N) and phosphorus (P) are two key traits of plants for ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on the stoichiometric patterns of trees and grasses, leaving a significant knowledge gap for shrubs. In this study, we explored the intraspecific and interspecific variations of leaf N and P concentrations in response to the changes in climate, soil property, and evolutionary history. We analysed 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China encompassing 46.1° (86.7-132.8° E) in longitude and 19.8° (32.6-52.4° N) in latitude. Leaf N concentrations decreased with precipitation, while leaf P concentrations decreased with temperature and increased with precipitation and soil total P concentrations. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentrations were less conserved than leaf N concentrations. At the community level, climate explained more interspecific variation of leaf nutrient concentrations, while soil nutrients explained most of the intraspecific variation. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits. New patterns were discovered using our observations on specific regions and vegetation types, which improved our knowledge of broad biogeographic patterns of leaf chemical traits.

  18. Modeling leaf venation morphogenesis

    CERN Document Server

    Laguna, M F; Jagla, E A

    2007-01-01

    We explore the possibility that the formation of leaf venation patterns is driven by mechanical instabilities in the growing leaf. In contrast to the prevalent canalization hypothesis based on polar auxin transport, mechanical instabilities lead very naturally to hierarchical patterns with an abundant number of closed loops as they exists in almost every leaf venation. We propose a continuum model where the vein formation is driven by a mechanical collapse of the mesophyll layer in the growing leaf, and present a numerical study of this model using a phase field approach. The results show the same qualitative features as real venation patterns and, furthermore, have the same statistical properties.

  19. Leaf expansion and biomass allocation in wild wheat (Aegilops) species

    NARCIS (Netherlands)

    Bultynck, L.J.A. (Lieve Jenny Alfons)

    2002-01-01

    Fast expansion of leaf area is an important trait to select for in cereal crop species, especially in arid environments. It is associated with higher crop water-use efficiency, higher above-ground biomass production and yield, and increased competitive ability. This thesis examined the physiological

  20. Características anatômicas da lâmina foliar e do colmo de gramíneas forrageiras tropicais, em função do nível de inserção no perfilho, da idade e da estação de crescimento Anatomical traits of leaf blade and stem of tropical forage grasses, according to level of insertion on the grass tiller, age and season of growth

    Directory of Open Access Journals (Sweden)

    Domingos Sávio Campos Paciullo

    2002-04-01

    proportion of epidermis, xylem, phloem, parenchyma bundle sheath, sclerenchyma, stem parenchyma and leaf blade mesophyll were estimated. The thickness of cell wall of metaxylem vessels and sclerenchyma were evaluated. Leaf tissue proportion changed neither with age nor season of growth; thickness of leaf sclerenchyma cell wall was the only trait to change with age. Leaf from the top layer showed higher proportion of sclerenchyma, parenchyma bundle sheath and xylem as well as thicker cell wall in sclerenchyma and metaxylem; while leaves from the bottom layer had higher proportion of mesophyll and thinner sclerenchyma and metaxylem cell walls. While the parenchyma proportion of the stem decreased, the relative area of the sclerenchyma and the cell wall thickness increased as the plant aged. These traits showed greater values in summer samples.

  1. Nutrient resorption is associated with leaf vein density and growth performance of dipterocarp tree species

    NARCIS (Netherlands)

    Zhang, J.L.; Zhang, S.B.; Chen, Y.J.; Zhang, Y.P.; Poorter, L.

    2015-01-01

    1.Nutrient resorption is important for the nutrient budget of plants, but little is known about which plant traits mediate nutrient resorption, how resorption efficiency is associated with other leaf traits and whether nutrient resorption has an impact on plant growth. 2.In this study, 17 dipterocar

  2. Leaf hydraulic conductance varies with vein anatomy across A rabidopsis thaliana wild-type and leaf vein mutants

    NARCIS (Netherlands)

    Caringella, M.A.; Bongers, F.J.; Sack, L.

    2015-01-01

    Leaf venation is diverse across plant species and has practical applications from paleobotany to modern agriculture. However, the impact of vein traits on plant performance has not yet been tested in a model system such as Arabidopsis thaliana. Previous studies analysed cotyledons of A. thaliana vei

  3. Trait values, not trait plasticity, best explain invasive species' performance in a changing environment.

    Science.gov (United States)

    Matzek, Virginia

    2012-01-01

    The question of why some introduced species become invasive and others do not is the central puzzle of invasion biology. Two of the principal explanations for this phenomenon concern functional traits: invasive species may have higher values of competitively advantageous traits than non-invasive species, or they may have greater phenotypic plasticity in traits that permits them to survive the colonization period and spread to a broad range of environments. Although there is a large body of evidence for superiority in particular traits among invasive plants, when compared to phylogenetically related non-invasive plants, it is less clear if invasive plants are more phenotypically plastic, and whether this plasticity confers a fitness advantage. In this study, I used a model group of 10 closely related Pinus species whose invader or non-invader status has been reliably characterized to test the relative contribution of high trait values and high trait plasticity to relative growth rate, a performance measure standing in as a proxy for fitness. When grown at higher nitrogen supply, invaders had a plastic RGR response, increasing their RGR to a much greater extent than non-invaders. However, invasive species did not exhibit significantly more phenotypic plasticity than non-invasive species for any of 17 functional traits, and trait plasticity indices were generally weakly correlated with RGR. Conversely, invasive species had higher values than non-invaders for 13 of the 17 traits, including higher leaf area ratio, photosynthetic capacity, photosynthetic nutrient-use efficiency, and nutrient uptake rates, and these traits were also strongly correlated with performance. I conclude that, in responding to higher N supply, superior trait values coupled with a moderate degree of trait variation explain invasive species' superior performance better than plasticity per se.

  4. Plant functional traits have globally consistent effects on competition.

    Science.gov (United States)

    Kunstler, Georges; Falster, Daniel; Coomes, David A; Hui, Francis; Kooyman, Robert M; Laughlin, Daniel C; Poorter, Lourens; Vanderwel, Mark; Vieilledent, Ghislain; Wright, S Joseph; Aiba, Masahiro; Baraloto, Christopher; Caspersen, John; Cornelissen, J Hans C; Gourlet-Fleury, Sylvie; Hanewinkel, Marc; Herault, Bruno; Kattge, Jens; Kurokawa, Hiroko; Onoda, Yusuke; Peñuelas, Josep; Poorter, Hendrik; Uriarte, Maria; Richardson, Sarah; Ruiz-Benito, Paloma; Sun, I-Fang; Ståhl, Göran; Swenson, Nathan G; Thompson, Jill; Westerlund, Bertil; Wirth, Christian; Zavala, Miguel A; Zeng, Hongcheng; Zimmerman, Jess K; Zimmermann, Niklaus E; Westoby, Mark

    2016-01-14

    Phenotypic traits and their associated trade-offs have been shown to have globally consistent effects on individual plant physiological functions, but how these effects scale up to influence competition, a key driver of community assembly in terrestrial vegetation, has remained unclear. Here we use growth data from more than 3 million trees in over 140,000 plots across the world to show how three key functional traits--wood density, specific leaf area and maximum height--consistently influence competitive interactions. Fast maximum growth of a species was correlated negatively with its wood density in all biomes, and positively with its specific leaf area in most biomes. Low wood density was also correlated with a low ability to tolerate competition and a low competitive effect on neighbours, while high specific leaf area was correlated with a low competitive effect. Thus, traits generate trade-offs between performance with competition versus performance without competition, a fundamental ingredient in the classical hypothesis that the coexistence of plant species is enabled via differentiation in their successional strategies. Competition within species was stronger than between species, but an increase in trait dissimilarity between species had little influence in weakening competition. No benefit of dissimilarity was detected for specific leaf area or wood density, and only a weak benefit for maximum height. Our trait-based approach to modelling competition makes generalization possible across the forest ecosystems of the world and their highly diverse species composition.

  5. Leaf Size in Swietenia

    Science.gov (United States)

    Charles B. Briscoe; F. Bruce. Lamb

    1962-01-01

    A study was made of the putative hybrid of bigleaf and small-leaf mahoganies. Initial measurements indicated that bigleaf mahogany can be distinguished from small-leaf mahogany by gross measurements of leaflets. Isolated mother trees yield typical progeny. Typical mother trees in mixed stands yield like progeny plus, usually, mediumleaf progeny. Mediumleaf mother trees...

  6. Seasonal changes in birch leaf chemistry: are there trade-offs between leaf growth and accumulation of phenolics?

    Science.gov (United States)

    Riipi, Marianna; Ossipov, Vladimir; Lempa, Kyösti; Haukioja, Erkki; Koricheva, Julia; Ossipova, Svetlana; Pihlaja, Kalevi

    2002-02-01

    Several plant-herbivore hypotheses are based on the assumption that plants cannot simultaneously allocate resources to growth and defence. We studied seasonal patterns in allocation to growth and putatively defensive compounds by monitoring several chemical and physical traits in the leaves of mountain birch from early June (budburst) to late September (leaf senescence). We found significant seasonal changes in all measured characteristics, both in terms of concentrations (mg g(-1)) and amounts (mg leaf(-1)). Changes were very rapid in the spring, slow in the middle of the season, and there was another period of fast changes in the senescing leaves. Co-occurring changes in physical leaf traits and concentrations of several compounds indicated a seasonal decline in foliage suitability for herbivores. Concentrations of protein and free amino acids declined through the growing season whereas individual sugars showed variable seasonal patterns. The seasonal trends of phenolic groups differed drastically: concentrations of soluble proanthocyanidins increased through the season, whereas cell wall-bound proanthocyanidins, gallotannins and flavonoid glycosides declined after an initial increase in young leaves. We failed to find proof that the seasonal accumulation of phenolics would have been seriously compromised by leaf or shoot growth, as assumed by the growth/differentiation balance hypothesis and the protein competition model hypothesis. On the contrary, there was a steady increase in the total amount of phenolics per leaf even during the most active leaf growth.

  7. Plant Thermoregulation: Energetics, Trait-Environment Interactions, and Carbon Economics.

    Science.gov (United States)

    Michaletz, Sean T; Weiser, Michael D; Zhou, Jizhong; Kaspari, Michael; Helliker, Brent R; Enquist, Brian J

    2015-12-01

    Building a more predictive trait-based ecology requires mechanistic theory based on first principles. We present a general theoretical approach to link traits and climate. We use plant leaves to show how energy budgets (i) provide a foundation for understanding thermoregulation, (ii) explain mechanisms driving trait variation across environmental gradients, and (iii) guide selection on functional traits via carbon economics. Although plants are often considered to be poikilotherms, the data suggest that they are instead limited homeotherms. Leaf functional traits that promote limited homeothermy are adaptive because homeothermy maximizes instantaneous and lifetime carbon gain. This theory provides a process-based foundation for trait-climate analyses and shows that future studies should consider plant (not only air) temperatures.

  8. Leaf hydraulic conductance varies with vein anatomy across Arabidopsis thaliana wild-type and leaf vein mutants.

    Science.gov (United States)

    Caringella, Marissa A; Bongers, Franca J; Sack, Lawren

    2015-12-01

    Leaf venation is diverse across plant species and has practical applications from paleobotany to modern agriculture. However, the impact of vein traits on plant performance has not yet been tested in a model system such as Arabidopsis thaliana. Previous studies analysed cotyledons of A. thaliana vein mutants and identified visible differences in their vein systems from the wild type (WT). We measured leaf hydraulic conductance (Kleaf ), vein traits, and xylem and mesophyll anatomy for A. thaliana WT (Col-0) and four vein mutants (dot3-111 and dot3-134, and cvp1-3 and cvp2-1). Mutant true leaves did not possess the qualitative venation anomalies previously shown in the cotyledons, but varied quantitatively in vein traits and leaf anatomy across genotypes. The WT had significantly higher mean Kleaf . Across all genotypes, there was a strong correlation of Kleaf with traits related to hydraulic conductance across the bundle sheath, as influenced by the number and radial diameter of bundle sheath cells and vein length per area. These findings support the hypothesis that vein traits influence Kleaf , indicating the usefulness of this mutant system for testing theory that was primarily established comparatively across species, and supports a strong role for the bundle sheath in influencing Kleaf .

  9. Principal Component Analysis of Some Quantitative and Qualitative Traits in Iranian Spinach Landraces

    Directory of Open Access Journals (Sweden)

    Mohebodini Mehdi

    2017-08-01

    Full Text Available Landraces of spinach in Iran have not been sufficiently characterised for their morpho-agronomic traits. Such characterisation would be helpful in the development of new genetically improved cultivars. In this study 54 spinach accessions collected from the major spinach growing areas of Iran were evaluated to determine their phenotypic diversity profile of spinach genotypes on the basis of 10 quantitative and 9 qualitative morpho-agronomic traits. High coefficients of variation were recorded in some quantitative traits (dry yield and leaf area and all of the qualitative traits. Using principal component analysis, the first four principal components with eigen-values more than 1 contributed 87% of the variability among accessions for quantitative traits, whereas the first four principal components with eigen-values more than 0.8 contributed 79% of the variability among accessions for qualitative traits. The most important relations observed on the first two principal components were a strong positive association between leaf width and petiole length; between leaf length and leaf numbers in flowering; and among fresh yield, dry yield and petiole diameter; a near zero correlation between days to flowering with leaf width and petiole length. Prickly seeds, high percentage of female plants, smooth leaf texture, high numbers of leaves at flowering, greygreen leaves, erect petiole attitude and long petiole length are important characters for spinach breeding programmes.

  10. Palm Functional Traits: which traits matter and how do we measure them?

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Balslev, Henrik; Barfod, Anders S.

    as our ability to predict the consequences of environmental change. At the same time, palms have emerged as a model group for tropical forest community ecology, macroecology and biogeography. However, the functional ecology of palms is relatively little explored, which is unfortunate given the important...... role of palms in tropical forest ecosystems. We review data availability for palms for four traits that are commonly used in functional plant ecology: specific leaf area (SLA), wood density, seed size, and maximum height. We suggest that palm functional ecology is impeded by some of the standard...... allow capturing leaf economics across large parts of the palm family with reasonable amounts of time and money....

  11. Foundation species influence trait-based community assembly.

    Science.gov (United States)

    Schöb, Christian; Butterfield, Bradley J; Pugnaire, Francisco I

    2012-11-01

    Here, we incorporate facilitation into trait-based community assembly theory by testing two mutually compatible facilitative mechanisms: changes in the environmental filter, causing either an increase in the range of trait values (i.e. a range expansion effect) and/or a shift in trait distributions (i.e. a range shift effect); and changes in trait spacing, suggesting an effect on niche differentiation. We analyzed the distribution of three functional traits - leaf dry matter content, specific leaf area and lateral spread - of plant communities dominated by a cushion-forming foundation species at four sites differing in elevation and aspect. We found support for environmental filtering and niche differentiation mechanisms by cushions, with filtering effects (in particular range shifts) increasing with environmental severity at higher elevation. The effect size of cushions on trait distribution was similar to that of environmental gradients caused by elevation and aspect. The consideration of intraspecific trait variability improved the detection of cushion effects on trait distributions. Our results highlight the importance of facilitation in the modification of taxonomic and functional diversity of ecological communities, and indicate that facilitation can occur through combined effects on environmental filtering and niche differentiation, with strong environmental context dependence of each mechanism.

  12. Dominant Gene cplsr1 Corresponding to Premature Leaf Senescence Resistance in Cotton (Gossypium hirsutum L.)

    Institute of Scientific and Technical Information of China (English)

    Jingqing Zhao; Tengfei Jiang; Zhi Liu; Wenwei Zhang; Guiliang Jian; Fangjun Qi

    2012-01-01

    Cotton (Gossypium hirsutum L.) premature leaf senescence-resistant inbred XLZ33 and senescencesusceptible inbred lines XLZ13 were selected and crossed to produce F1,F1-reciprocal,F2 and BC1 generations for evaluation of leaf senescence process and inheritance.The results showed that leaf senescence processes for XLZ13 and XLZ33 were obviously different and leaf senescence traits could be distinguished between the two parents at particular periods of cotton growth.Inheritance anlysis for the cotton premature leaf senescence resistant trait further showed that the segregation in the F2 fit a 3:1 ratio inheritance pattern,with resistance being dominant.The backcross of F1 to the susceptible parent produced a 1:1 ratio,confirming that cotton premature leaf senescence resistant trait was from a single gene.The single dominant gene controlling cotton premature leaf senescence resistance in XLZ33 was named as cotton premature leaf senescence resistance 1,with the symbol cplsr1.

  13. Leaf growth is conformal

    CERN Document Server

    Alim, Karen; Shraiman, Boris I; Boudaoud, Arezki

    2016-01-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour.

  14. Leaf growth is conformal

    Science.gov (United States)

    Alim, Karen; Armon, Shahaf; Shraiman, Boris I.; Boudaoud, Arezki

    2016-10-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour.

  15. Biplot analysis of trait relations of spinach (Spinacia oleracea L. landraces

    Directory of Open Access Journals (Sweden)

    Sabaghnia Naser

    2016-01-01

    Full Text Available Interest in growing winter spinach (Spinacia oleracea L. in Iran is increasing due to its good nutritional potential returns relative to other vegetable crops. The objectives of this research were to investigate the interrelationships among different traits of spinach and to evaluate different Iranian spinach landraces with application of the genotype × trait (GT biplot methodology in visualizing research data. 81 spinach landraces were grown during 2-years according to randomized complete block design with four replications. Ranking of the genotypes based on the ideal entry revealed that genotypes G1, G20, G7, G8, G9, G27, G49 G70 and G79 were higher in the measured traits and could be good candidates for improving most of the measured traits. Ranking of traits for the leaf yield showed that petiole diameter, petiole length, leaf numbers at flowering, 1000-seed weight and root dry weight were the most discriminating traits which influence spinach leaf yield at both years. There were 9 winning genotypes and 4 which-won-where patterns at the first year while there were 8 winning genotypes and 4 which-won-where patterns at the second year. As a result, the findings from our study are as follows: (i traits leaf numbers at flowering, leaf length, leaf width, leaf area, petiole diameter and petiole length could be as selection indices for spinach leaf yield improvement, (ii genotypes G1, G20, G7, G8, G9, G27, G49 G70, and G79 were the most favorable and is thus recommended for commercial release or incorporating in breeding programs; (iii the GT biplot method can be used to identify superior genotypes in other crops and in other parts of the world.

  16. Path analysis of the productive traits in Sorghum species

    Directory of Open Access Journals (Sweden)

    Ikanović Jela

    2011-01-01

    Full Text Available This research studied the phenotypic correlation coefficients between three Sorghum species, namely forage sorghum S. bicolor Moench. (c. NS-Džin, Sudan grass S. sudanense L. (c. Zora and interspecies hybrid S. bicolor x S. sudanense (c. Siloking. The analyses were performed on plant material samples taken from the first cutting, when plants were in the beginning phase of tasseling. The following morphologic traits were studied: plant height, number of leaves per plant, stem leaf weight and mean stem weight. Additionally, their direct and indirect effect on dependent variable green biomass yield was analyzed, for which path coefficients were calculated. This method enables more quality and full insight into relations existing among the studied traits, more precise establishment of cause-effect connections among them, as well as to separate direct from indirect effects of any particular trait on dependent variable, being biomass yield in this case. The analysis of phenotypic coefficients revealed differences in direct and indirect effect of certain traits on dependent variable. Sudan grass had the highest stem (2.281 m and most leaves per plant (7.917. Forage sorghum had the largest leaf weight per plant (49.05 g, while interspecies hybrid had the highest mean stem weight (80.798 g. Variations of these morphologic traits among species were found to be significant and very significant. Morphologic traits - stem height and weight significantly affected sorghum green biomass yield. Leaf number and leaf portion in total biomass were negatively correlated with yield. Cultivars differed significantly regarding morphologic and productive traits. Sudan grass had the lowest green biomass yield, while forage sorghum and interspecies hybrid had significant yield increase.

  17. Quantitative genetic analysis indicates natural selection on leaf phenotypes across wild tomato species (Solanum sect. Lycopersicon; Solanaceae).

    Science.gov (United States)

    Muir, Christopher D; Pease, James B; Moyle, Leonie C

    2014-12-01

    Adaptive evolution requires both raw genetic material and an accessible path of high fitness from one fitness peak to another. In this study, we used an introgression line (IL) population to map quantitative trait loci (QTL) for leaf traits thought to be associated with adaptation to precipitation in wild tomatoes (Solanum sect. Lycopersicon; Solanaceae). A QTL sign test showed that several traits likely evolved under directional natural selection. Leaf traits correlated across species do not share a common genetic basis, consistent with a scenario in which selection maintains trait covariation unconstrained by pleiotropy or linkage disequilibrium. Two large effect QTL for stomatal distribution colocalized with key genes in the stomatal development pathway, suggesting promising candidates for the molecular bases of adaptation in these species. Furthermore, macroevolutionary transitions between vastly different stomatal distributions may not be constrained when such large-effect mutations are available. Finally, genetic correlations between stomatal traits measured in this study and data on carbon isotope discrimination from the same ILs support a functional hypothesis that the distribution of stomata affects the resistance to CO2 diffusion inside the leaf, a trait implicated in climatic adaptation in wild tomatoes. Along with evidence from previous comparative and experimental studies, this analysis indicates that leaf traits are an important component of climatic niche adaptation in wild tomatoes and demonstrates that some trait transitions between species could have involved few, large-effect genetic changes, allowing rapid responses to new environmental conditions.

  18. Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances

    Directory of Open Access Journals (Sweden)

    Florian eFort

    2015-02-01

    Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.

  19. The hebridological analysis of productivity traits in pea hybrids

    Directory of Open Access Journals (Sweden)

    Світлана Володимирівна Коблай

    2015-09-01

    Full Text Available To study the nature of inheritance of quantitative traits that influence productivity of pea hybrids were obtained first and second generations for which sample and varieties with different leaf morphotype are served as parental form. As the results of hybridological analysis it is determined the degree of domination and revealed the heterosis combinations

  20. Combining Abilities of Agronomic and Morphological Traits in Burley Tobacco

    Directory of Open Access Journals (Sweden)

    Jasminka Butorac

    2000-09-01

    Full Text Available Two-year investigations (1998-1999 of diallel crosses with four parent cultivars of burley tobacco (TN 86, Saturn, Bs 92, Bols 100 and their six F1 hybrids were carried out at the experimental field of Tobacco Institute Zagreb in Pitomača. The trial was set up according to the RCBD in four replications. Standard agrotehnics for this tobacco type were applied in tobacco growing. The goal of these investigation was to estimate on specific genetic materials the values of parent genotypes as combiners and the best specific cross combinations for agronomic (yield, price and income and morphological traits (topping height, leaf number, days to flowering, leaf length, leaf width and leaf area and internode length. Significant differences between parents and F1 hybrids were found for all investigation traits and years according to analysis of variance. Significant general and specific combining ability were also estimated for all investigation traits, except of specific combining ability for price in both investigation years. According to the GCA/SCA ratio, a higher GCA values were estimated for most traits. The cultivars TN 86 and Bs 92 were the best general combiners, while TN 86 x Bs 92, TN 86 x Bols 100 i Bs 92 x Bols 100 were the best specific combinations in both investigation years.

  1. Productive leaf functional traits of Chinese savanna species.

    NARCIS (Netherlands)

    Zhang, J.L.; Poorter, L.; Cao, K.F.

    2012-01-01

    The river valleys in Southwest China are characterized by a dry–hot climate and relatively rich soils, and host valley-type savannas that are dominated by deciduous species. However, little is known about the ecological adaptations of Chinese savanna plants to the local environments. We hypothesize

  2. Generality of leaf traits relationships of dominant species along the ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... secondary succession, reaching the lowest point in the early forest community. The Nm and Chl ... Studies on a range of ecosystems have shown that deciduous ... vegetations belong to the north warm temperate zone and the.

  3. Using Plant Functional Traits and Phylogenies to Understand Patterns of Plant Community Assembly in a Seasonal Tropical Forest in Lao PDR.

    Science.gov (United States)

    Satdichanh, Manichanh; Millet, Jérôme; Heinimann, Andreas; Nanthavong, Khamseng; Harrison, Rhett D

    2015-01-01

    Plant functional traits reflect different evolutionary responses to environmental variation, and among extant species determine the outcomes of interactions between plants and their environment, including other plant species. Thus, combining phylogenetic and trait-based information can be a powerful approach for understanding community assembly processes across a range of spatial scales. We used this approach to investigate tree community composition at Phou Khao Khouay National Park (18°14'-18°32'N; 102°38'- 102°59'E), Laos, where several distinct forest types occur in close proximity. The aim of our study was to examine patterns of plant community assembly across the strong environmental gradients evident at our site. We hypothesized that differences in tree community composition were being driven by an underlying gradient in soil conditions. Thus, we predicted that environmental filtering would predominate at the site and that the filtering would be strongest on sandier soil with low pH, as these are the conditions least favorable to plant growth. We surveyed eleven 0.25 ha (50x50 m) plots for all trees above 10 cm dbh (1221 individual trees, including 47 families, 70 genera and 123 species) and sampled soils in each plot. For each species in the community, we measured 11 commonly studied plant functional traits covering both the leaf and wood economic spectrum traits and we reconstructed a phylogenetic tree for 115 of the species in the community using rbcL and matK sequences downloaded from Genebank (other species were not available). Finally we compared the distribution of trait values and species at two scales (among plots and 10x10m subplots) to examine trait and phylogenetic community structures. Although there was strong evidence that an underlying soil gradient was determining patterns of species composition at the site, our results did not support the hypothesis that the environmental filtering dominated community assembly processes. For the

  4. Using Plant Functional Traits and Phylogenies to Understand Patterns of Plant Community Assembly in a Seasonal Tropical Forest in Lao PDR.

    Directory of Open Access Journals (Sweden)

    Manichanh Satdichanh

    Full Text Available Plant functional traits reflect different evolutionary responses to environmental variation, and among extant species determine the outcomes of interactions between plants and their environment, including other plant species. Thus, combining phylogenetic and trait-based information can be a powerful approach for understanding community assembly processes across a range of spatial scales. We used this approach to investigate tree community composition at Phou Khao Khouay National Park (18°14'-18°32'N; 102°38'- 102°59'E, Laos, where several distinct forest types occur in close proximity. The aim of our study was to examine patterns of plant community assembly across the strong environmental gradients evident at our site. We hypothesized that differences in tree community composition were being driven by an underlying gradient in soil conditions. Thus, we predicted that environmental filtering would predominate at the site and that the filtering would be strongest on sandier soil with low pH, as these are the conditions least favorable to plant growth. We surveyed eleven 0.25 ha (50x50 m plots for all trees above 10 cm dbh (1221 individual trees, including 47 families, 70 genera and 123 species and sampled soils in each plot. For each species in the community, we measured 11 commonly studied plant functional traits covering both the leaf and wood economic spectrum traits and we reconstructed a phylogenetic tree for 115 of the species in the community using rbcL and matK sequences downloaded from Genebank (other species were not available. Finally we compared the distribution of trait values and species at two scales (among plots and 10x10m subplots to examine trait and phylogenetic community structures. Although there was strong evidence that an underlying soil gradient was determining patterns of species composition at the site, our results did not support the hypothesis that the environmental filtering dominated community assembly processes

  5. Trait-Based Community Assembly along an Elevational Gradient in Subalpine Forests: Quantifying the Roles of Environmental Factors in Inter- and Intraspecific Variability.

    Directory of Open Access Journals (Sweden)

    Ya-Huang Luo

    Full Text Available Understanding how communities respond to environmental variation is a central goal in ecology. Plant communities respond to environmental gradients via intraspecific and/or interspecific variation in plant functional traits. However, the relative contribution of these two responses to environmental factors remains poorly tested. We measured six functional traits (height, leaf thickness, specific leaf area (SLA, leaf carbon concentration (LCC, leaf nitrogen concentration (LNC and leaf phosphorus concentration (LPC for 55 tree species occurring at five elevations across a 1200 m elevational gradient of subalpine forests in Yulong Mountain, Southwest China. We examined the relative contribution of interspecific and intraspecific traits variability based on community weighted mean trait values and functional diversity, and tested how different components of trait variation respond to different environmental axes (climate and soil variables. Species turnover explained the largest amount of variation in leaf morphological traits (leaf thickness and SLA across the elevational gradient. However, intraspecific variability explained a large amount of variation (49.3%-76.3% in three other traits (height, LNC and LPC despite high levels of species turnover. The detection of limiting similarity in community assembly was improved when accounting for both intraspecific and interspecific variability. Different components of trait variation respond to different environmental axes, especially soil water content and climatic variables. Our results indicate that intraspecific variation is critical for understanding community assembly and evaluating community response to environmental change.

  6. Evolutionary Position and Leaf Toughness Control Chemical Transformation of Litter, and Drought Reinforces This Control: Evidence from a Common Garden Experiment across 48 Species.

    Science.gov (United States)

    Pan, Xu; Song, Yao-Bin; Jiang, Can; Liu, Guo-Fang; Ye, Xue-Hua; Xie, Xiu-Fang; Hu, Yu-Kun; Zhao, Wei-Wei; Cui, Lijuan; Cornelissen, Johannes H C; Dong, Ming; Prinzing, Andreas

    2015-01-01

    Plant leaf litter is an important source of soil chemicals that are essential for the ecosystem and changes in leaf litter chemical traits during decomposition will determine the availability of multiple chemical elements recycling in the ecosystem. However, it is unclear whether the changes in litter chemical traits during decomposition and their similarities across species can be predicted, respectively, using other leaf traits or using the phylogenetic relatedness of the litter species. Here we examined the fragmentation levels, mass losses, and the changes of 10 litter chemical traits during 1-yr decomposition under different environmental conditions (within/above surrounding litter layer) for 48 temperate tree species and related them to an important leaf functional trait, i.e. leaf toughness. Leaf toughness could predict the changes well in terms of amounts, but poorly in terms of concentrations. Changes of 7 out of 10 litter chemical traits during decomposition showed a significant phylogenetic signal notably when litter was exposed above surrounding litter. These phylogenetic signals in element dynamics were stronger than those of initial elementary composition. Overall, relatively hard-to-measure ecosystem processes like element dynamics during decomposition could be partly predicted simply from phylogenies and leaf toughness measures. We suggest that the strong phylogenetic signals in chemical ecosystem functioning of species may reflect the concerted control by multiple moderately conserved traits, notably if interacting biota suffer microclimatic stress and spatial isolation from ambient litter.

  7. Evolutionary Position and Leaf Toughness Control Chemical Transformation of Litter, and Drought Reinforces This Control: Evidence from a Common Garden Experiment across 48 Species.

    Directory of Open Access Journals (Sweden)

    Xu Pan

    Full Text Available Plant leaf litter is an important source of soil chemicals that are essential for the ecosystem and changes in leaf litter chemical traits during decomposition will determine the availability of multiple chemical elements recycling in the ecosystem. However, it is unclear whether the changes in litter chemical traits during decomposition and their similarities across species can be predicted, respectively, using other leaf traits or using the phylogenetic relatedness of the litter species. Here we examined the fragmentation levels, mass losses, and the changes of 10 litter chemical traits during 1-yr decomposition under different environmental conditions (within/above surrounding litter layer for 48 temperate tree species and related them to an important leaf functional trait, i.e. leaf toughness. Leaf toughness could predict the changes well in terms of amounts, but poorly in terms of concentrations. Changes of 7 out of 10 litter chemical traits during decomposition showed a significant phylogenetic signal notably when litter was exposed above surrounding litter. These phylogenetic signals in element dynamics were stronger than those of initial elementary composition. Overall, relatively hard-to-measure ecosystem processes like element dynamics during decomposition could be partly predicted simply from phylogenies and leaf toughness measures. We suggest that the strong phylogenetic signals in chemical ecosystem functioning of species may reflect the concerted control by multiple moderately conserved traits, notably if interacting biota suffer microclimatic stress and spatial isolation from ambient litter.

  8. Intraspecific variability and reaction norms of forest understory plant species traits

    Science.gov (United States)

    Burton, Julia I.; Perakis, Steven; McKenzie, Sean C.; Lawrence, Caitlin E.; Puettmann, Klaus J.

    2017-01-01

    Trait-based models of ecological communities typically assume intraspecific variation in functional traits is not important, though such variation can change species trait rankings along gradients in resources and environmental conditions, and thus influence community structure and function.We examined the degree of intraspecific relative to interspecific variation, and reaction norms of 11 functional traits for 57 forest understory plant species, including: intrinsic water-use efficiency (iWUE), Δ15N, 5 leaf traits, 2 stem traits and 2 root traits along gradients in light, nitrogen, moisture and understory cover.Our results indicate that interspecific trait variation exceeded intraspecific variation by at least 50% for most, but not all traits. Intraspecific variation in Δ15N, iWUE, leaf nitrogen content and root traits was high (47-70%) compared with most leaf traits and stem traits (13-38%).Δ15N varied primarily along gradients in abiotic conditions, while light and understory cover were relatively less important. iWUE was related primarily to light transmission, reflecting increases in photosynthesis relative to stomatal conductance. Leaf traits varied mainly as a function of light availability, with some reaction norms depending on understory cover. Plant height increased with understory cover, while stem specific density was related primarily to light. Resources, environmental conditions and understory cover did not contribute strongly to the observed variation in root traits.Gradients in resources, environmental conditions and competition all appear to control intraspecific variability in most traits to some extent. However, our results suggest that species cross-over (i.e., trait rank reversals) along the gradients measured here are generally not a concern.Intraspecific variability in understory plant species traits can be considerable. However, trait data collected under a narrow range of environmental conditions appears sufficient to establish species

  9. Relative contribution of soil, management and traits to co-variations of multiple ecosystem properties in grasslands.

    Science.gov (United States)

    Gos, Pierre; Loucougaray, Grégory; Colace, Marie-Pascale; Arnoldi, Cindy; Gaucherand, Stéphanie; Dumazel, Daphné; Girard, Lucie; Delorme, Sarah; Lavorel, Sandra

    2016-04-01

    Ecological intensification promotes the better use of ecosystem functioning for agricultural production and as a provider of additional regulation and cultural services. We investigated the mechanisms underpinning potential ecological intensification of livestock production in the Vercors mountains (France). We quantified the variations in seven ecosystem properties associated with key ecosystem services: above-ground biomass production at first harvest, fodder digestibility, plant species richness, soil organic matter content, soil carbon content, total microbial biomass and soil bacteria:fungi ratio across 39 grassland plots representing varying management types and intensity. Our analyses confirmed joint effects of management, traits and soil abiotic parameters on variations in ecosystem properties, with the combination of management and traits being most influential. The variations explained by traits were consistent with the leaf economics spectrum model and its implications for ecosystem functioning. The observed independence between ecosystem properties relevant to production (forage biomass, digestibility and nutrient turnover) on the one hand and soil stocks (organic matter, carbon and microbial stocks) on the other hand suggests that an intensification of fodder production might be compatible with the preservation of the soil capital. We highlight that appropriate choices regarding various practices, such as the first date of grazing or mowing being dependent on soil moisture, have important consequences on a number of ecosystem properties relevant for ecosystem services and may influence biodiversity patterns. Such avenues for ecological intensification should be considered as part of further landscape- and farm-scale analyses of the relationships between farm functioning and ecosystem services.

  10. Kaolin-based foliar reflectant and water deficit influence Malbec leaf and berry temperature, pigments, and photosynthesis

    Science.gov (United States)

    The effects of a kaolin-based foliar reflectant on traits of commercial interest in the red-skinned wine grape cultivar Malbec (Vitis vinifera L.) were evaluated over three growing seasons by measuring the surface temperatures of leaves and clusters, leaf-level assimilation, leaf and berry pigment c...

  11. Quantitative gene-gene and gene-environment mapping for leaf shape variation using tree-based models

    Science.gov (United States)

    Leaf shape traits have long been a focus of many disciplines, but searching for complex genetic and environmental interactive mechanisms regulating leaf shape variation has not yet been well developed. The question of the respective roles of gene and environment and how they interplay to modulate l...

  12. Uncertainty quantified trait predictions

    Science.gov (United States)

    Fazayeli, Farideh; Kattge, Jens; Banerjee, Arindam; Schrodt, Franziska; Reich, Peter

    2015-04-01

    Functional traits of organisms are key to understanding and predicting biodiversity and ecological change, which motivates continuous collection of traits and their integration into global databases. Such composite trait matrices are inherently sparse, severely limiting their usefulness for further analyses. On the other hand, traits are characterized by the phylogenetic trait signal, trait-trait correlations and environmental constraints, all of which provide information that could be used to statistically fill gaps. We propose the application of probabilistic models which, for the first time, utilize all three characteristics to fill gaps in trait databases and predict trait values at larger spatial scales. For this purpose we introduce BHPMF, a hierarchical Bayesian extension of Probabilistic Matrix Factorization (PMF). PMF is a machine learning technique which exploits the correlation structure of sparse matrices to impute missing entries. BHPMF additionally utilizes the taxonomic hierarchy for trait prediction. Implemented in the context of a Gibbs Sampler MCMC approach BHPMF provides uncertainty estimates for each trait prediction. We present comprehensive experimental results on the problem of plant trait prediction using the largest database of plant traits, where BHPMF shows strong empirical performance in uncertainty quantified trait prediction, outperforming the state-of-the-art based on point estimates. Further, we show that BHPMF is more accurate when it is confident, whereas the error is high when the uncertainty is high.

  13. Canonical Correlation between the Leaf Quality Indicators of "Moderate Aroma" Flue-cured Tobacco

    Institute of Scientific and Technical Information of China (English)

    Lin; MENG; Yuangang; DAI; Chengdong; WANG; Shusheng; WANG; Wenjing; SONG; Yuanhua; WU; Yimin; XU

    2015-01-01

    In order to find out the correlation between tobacco quality evaluation indicators in China’s traditional " moderate aroma" tobaccoproducing areas and simplify the tobacco quality evaluation indicators,we evaluate the appearance quality and smoking quality of 143 flue-cured tobacco leaf samples in China’s " moderate aroma" tobacco-producing areas,test the physical traits and chemical component,and analyze the canonical correlation between four quality evaluation indicators. The results show that there is significant or extremely significant canonical correlation between four evaluation indicators( tobacco smoking quality,chemical component,appearance quality and physical trait quality); the cumulative variance contribution rate of evaluation indicators is in the order of chemical component( 69. 17%) > appearance quality( 68. 76%) > physical traits( 64. 13%); appearance quality is most closely related to physical traits( 93. 84%). The individual indicators for tobacco quality evaluation make different contribution to the correlation between quality evaluation indicators. The chemical component evaluation indicators mainly include total sugar and ratio of total sugar to betaine; sensory taste indicators mainly include aroma volume,smoke concentration,irritation and softness degree; physical trait evaluation indicators mainly include leaf weight,leaf length and leaf density; appearance quality indicators mainly include leaf organizational structure,color,maturity and identity. Studies have shown that in the large-scale ecoregion,using canonical correlation analysis to simplify tobacco quality evaluation indicators is feasible.

  14. Características produtivas e digestibilidade da farinha de folhas de mandioca em dietas de frangos de corte com e sem adição de enzimas Productive traits and digestibility of cassava leaf meal in broiler diets with or without addition of enzymes

    Directory of Open Access Journals (Sweden)

    Hunaldo Oliveira Silva

    2000-06-01

    Full Text Available Experimentos foram realizados a fim de determinar a digestibilidade (Experimento 1 e o efeito da inclusão de farinha de folhas de mandioca (FFM com e sem a adição de complexos multienzimáticos (CME em dietas de frangos de corte machos (Experimento 2, de linhagem Hubbard. Os CME utilizados foram compostos de Energex (beta-glucanase, pectinase, hemicelulase e Bio-Feed Alpha (beta-glucanase, amilase. No Experimento 1, utilizaram-se aves com 21 dias de idade, com o nível de inclusão 0-41,67% de FFM, para medir o coeficiente de digestibilidade da energia bruta e fibra bruta (CDEB/CDFB e determinar os valores de energia metabolizável aparente e corrigida (EMA/EMAn. No Experimento 2, utilizaram-se aves de 1-21 dias de idade, com níveis de inclusão de 0-10,34% de FFM, para avaliar o consumo médio de ração (CMR, o ganho de peso médio (GPM e a conversão alimentar média (CAM. No Experimento 1, houve diferença para os valores do CDEB, CDFB, EMA e EMAn, ocorrendo diminuição na digestibilidade, à medida que se elevaram os níveis de inclusão de FFM na dieta basal. Com a adição dos CME, evidenciou-se melhora nas características analisadas. A determinação dos valores de EMA e EMAn foram de 1697 e 1694 kcal/kg/MS FFM, respectivamente. No Experimento 2, o nível de maior inclusão de FFM foi o que apresentou o pior resultado para as características CMR, GPM e CAM, enquanto o nível 5,17% de FFM não prejudicou o desempenho dos animais. A adição do CME não melhorou o valor nutritivo da FFM.Experiments were carried out to determine the digestibility (Experiment 1 and the effect of the inclusion of cassava leaf meal (CLM with and without the addition of multi-enzyme complexes (MEC in male broiler diets (Experiment 2 of the Hubbard strain. The MECs used were made up of Energex (beta-glucanase, pectinase, hemicellulose and Bio-Feed Alpha (beta-glucanase, amylase. In Experiment 1, birds with 21 days of age were used, with the level of

  15. Association mapping for phenology and plant architecture in maize shows higher power for developmental traits compared with growth influenced traits.

    Science.gov (United States)

    Bouchet, S; Bertin, P; Presterl, T; Jamin, P; Coubriche, D; Gouesnard, B; Laborde, J; Charcosset, A

    2017-03-01

    Plant architecture, phenology and yield components of cultivated plants have repeatedly been shaped by selection to meet human needs and adaptation to different environments. Here we assessed the genetic architecture of 24 correlated maize traits that interact during plant cycle. Overall, 336 lines were phenotyped in a network of 9 trials and genotyped with 50K single-nucleotide polymorphisms. Phenology was the main factor of differentiation between genetic groups. Then yield components distinguished dents from lower yielding genetic groups. However, most of trait variation occurred within group and we observed similar overall and within group correlations, suggesting a major effect of pleiotropy and/or linkage. We found 34 quantitative trait loci (QTLs) for individual traits and six for trait combinations corresponding to PCA coordinates. Among them, only five were pleiotropic. We found a cluster of QTLs in a 5 Mb region around Tb1 associated with tiller number, ear row number and the first PCA axis, the latter being positively correlated to flowering time and negatively correlated to yield. Kn1 and ZmNIP1 were candidate genes for tillering, ZCN8 for leaf number and Rubisco Activase 1 for kernel weight. Experimental repeatabilities, numbers of QTLs and proportion of explained variation were higher for traits related to plant development such as tillering, leaf number and flowering time, than for traits affected by growth such as yield components. This suggests a simpler genetic determinism with larger individual QTL effects for the first category.

  16. Functional trait responses to grazing are mediated by soil moisture and plant functional group identity.

    Science.gov (United States)

    Zheng, Shuxia; Li, Wenhuai; Lan, Zhichun; Ren, Haiyan; Wang, Kaibo

    2015-12-11

    Abundant evidence has shown that grazing alters plant functional traits, community structure and ecosystem functioning of grasslands. Few studies, however, have tested how plant responses to grazing are mediated by resource availability and plant functional group identity. We examined the effects of grazing on functional traits across a broad range of species along a soil moisture gradient in Inner Mongolia grassland. Our results showed that trait syndromes of plant size (individual biomass) and shoot growth (leaf N content and leaf density) distinguished plant species responses to grazing. The effects of grazing on functional traits were mediated by soil moisture and dependent on functional group identity. For most species, grazing decreased plant height but increased leaf N and specific leaf area (SLA) along the moisture gradient. Grazing enhanced the community-weighted attributes (leaf NCWM and SLACWM), which were triggered mainly by the positive trait responses of annuals and biennials and perennial grasses, and increased relative abundance of perennial forbs. Our results suggest that grazing-induced species turnover and increased intraspecific trait variability are two drivers for the observed changes in community weighted attributes. The dominant perennial bunchgrasses exhibited mixed tolerance-resistance strategies to grazing and mixed acquisitive-conservative strategies in resource utilization.

  17. Identifying plant traits: a key aspect for suitable species selection in ecological restoration of semiarid slopes

    Science.gov (United States)

    Bochet, Esther; García-Fayos, Patricio

    2017-04-01

    In the context of ecological restoration, one of the greatest challenges for practitioners and scientists is to select suitable species for revegetation purposes. In semiarid environments where restoration projects often fail, little attention has been paid so far to the contribution of plant traits to species success. The objective of this study was to (1) identify plant traits associated with species success on four roadside situations along an erosion-productivity gradient, and (2) to provide an ecological framework for selecting suitable species on the basis of their morphological and functional traits, applied to semiarid environments. We analyzed the association of 10 different plant traits with species success of 296 species surveyed on the four roadside situations in a semiarid region (Valencia, Spain). Plant traits included general plant traits (longevity, woodiness) and more specific root-, seed- and leaf-related traits (root type, sprouting ability, seed mucilage, seed mass, seed susceptibility to removal, specific leaf area and leaf dry matter content). All of them were selected according to the prevailing limiting ecogeomorphological processes acting along the erosion-productivity gradient. We observed strong shifts along the erosion-productivity gradient in the traits associated to species success. At the harshest end of the gradient, the most intensely eroded and driest one, species success was mainly associated to seed resistance to removal by runoff and to resistance to drought. At the opposite end of the gradient, the most productive one, species success was associated to a competitive-ruderal plant strategy (herbaceous successful species with high specific leaf area and low leaf dry matter content). Our study provides an ecologically-based approach for selecting suitable native species on the basis or their morphological and functional traits and supports a differential trait-based selection of species as regards roadslope type and aspect. In

  18. Sexuality and Gender Role in Autism Spectrum Disorder: A Case Control Study

    OpenAIRE

    Susanne Bejerot; Eriksson, Jonna M.

    2014-01-01

    The 'extreme male brain theory of autism' describes an extreme male pattern of cognitive traits defined as strong systemising abilities paired with empathising weaknesses in autism spectrum disorder. However, beyond these cognitive traits, clinical observations have suggested an ambiguous gender-typed pattern regarding several sexually dimorphic traits. The aim of the present study was to investigate if patterns of non-cognitive sexually dimorphic traits differed between the autism spectrum d...

  19. Leaf size serves as a proxy for xylem vulnerability to cavitation in plantation trees.

    Science.gov (United States)

    Schreiber, Stefan G; Hacke, Uwe G; Chamberland, Sabrina; Lowe, Christopher W; Kamelchuk, David; Bräutigam, Katharina; Campbell, Malcolm M; Thomas, Barb R

    2016-02-01

    Hybrid poplars are an important renewable forest resource known for their high productivity. At the same time, they are highly vulnerable to water stress. Identifying traits that can serve as indicators for growth performance remains an important task, particularly under field conditions. Understanding which trait combinations translate to improved productivity is key in order to satisfy the demand for poplar wood in an uncertain future climate. In this study, we compared hydraulic and leaf traits among five hybrid poplar clones at 10 plantations in central Alberta. We also assessed the variation of these traits between 2- to 3-year-old branches from the lower to mid-crown and current-year long shoots from the mid to upper crown. Our results showed that (1) hybrid poplars differed in key hydraulic parameters between branch type, (2) variation of hydraulic traits among clones was relatively large for some clones and less for others, and (3) strong relationships between measured hydraulic traits, such as vessel diameter, cavitation resistance, xylem-specific and leaf-specific conductivity and leaf area, were observed. Our results suggest that leaf size could serve as an additional screening tool when selecting for drought-tolerant genotypes in forest management and tree improvement programmes.

  20. Auxin transport inhibitor induced low complexity petiolated leaves and sessile leaf-like stipules and architectures of heritable leaf and stipule mutants in Pisum sativum suggest that its simple lobed stipules and compound leaf represent ancestral forms in angiosperms.

    Science.gov (United States)

    Kumar, Arvind; Sharma, Vishakha; Khan, Moinuddin; Hindala, Mali Ram; Kumar, Sushil

    2013-04-01

    In angiosperms, leaf and stipule architectures are inherited species-specific traits. Variation in leaf and stipule sizes, and forms result from the interaction between abiotic and biotic stimuli, and gene regulatory network(s) that underlie the leaf and stipule developmental programme(s). Here, correspondence between variation in leaf and stipule architectures described for extant angiosperms and that induced mutationally and by imposition of stress in model angiosperm species, especially in Pisum sativum, was detected. Following inferences were drawn from the observations. (i) Several leaf forms in P. sativum have origin in fusion of stipule and leaf primordia. Perfoliate (and amplexicaul and connate) simple sessile leaves and sessile adnate leaves are the result of such primordial fusions. Reversal of changes in the gene regulatory network responsible for fusion products are thought to restore original stipule and leaf conditions. (ii) Compound leaf formation in several different model plants, is a result of promotion of pathways for such condition by gene regulatory networks directed by KNOx1 and LEAFY transcription factors or intercalation of the gene networks directed by them. (iii) Gene regulatory network for compound leaves in P. sativum when mutated generates highly complex compound leaves on one hand and simple leaves on other hand. These altered conditions are mutationally reversible. (vi) Simple leaves in model plants such as Arabidopsis thaliana despite overexpression of KNOx1 orthologues do not become compound. (v) All forms of leaves, including simple leaf, probably have origins in a gene regulatory network of the kind present in P. sativum.

  1. [The analysis of the causes of variability of the relationship between leaf dry mass and area in plants].

    Science.gov (United States)

    Vasfilov, S P

    2011-01-01

    The lamina dry mass: area ratio (LMA - Leaf Mass per Area) is a quite variable trait. Leaf dry mass consists of symplast mass (a set of all leaf protoplasts) and apoplast mass (a set of all cell walls in a leaf). The ratio between symplast and apoplast masses is positively related to any functional trait of leaf calculated per unit of dry mass. The value of this ratio is defined by cells size and their number per unit of leaf area, number of mesophyll cells layers and their differentiation between palisade and spongy ones, and also by density of cells packing. The LMA value is defined by leaf thickness and density. The extent and direction of variability in both leaf traits define the extent and direction of variability in LMA. Negative correlation between leaf thickness and density reduces the level of LMA variability. As a consequence of this correlation the following pattern emerges: the thinner a leaf, the denser it is. Changes in the traits that define the LMA value take place both within a species under the influence of environmental factors and between species that differ in leaf structure and functions. Light is the most powerful environmental factor that influences the LMA, increase in illumination leading to increase in LMA. This effect occurs during leaf growth at the expense of structural changes associated with the reduction of symplast/apoplast mass ratio. Under conditions of intense illumination, LMA may increase due to accumulation of starch. With regard to the majority of leaf functions, the mass of starch may be ascribed to apoplast. Starch accumulation in leaves is observed also under conditions of elevated CO2 concentration in the air. Under high illumination, however, LMA increases also due to increased apoplast contribution to leaf dry mass. Scarce mineral nutrition leads to LMA increase due to lowering of growth zones demands for phothosyntates and, therefore, to increase in starch content of leaves. High level of mineral nutrition during

  2. A single gene controls leaf background color in caladium (Araceae) and is tightly linked to genes for leaf main vein color, spotting and rugosity

    Science.gov (United States)

    Cao, Zhe; Sui, Shunzhao; Yang, Qian; Deng, Zhanao

    2017-01-01

    Modern cultivated caladiums (Caladium×hortulanum) are grown for their long-lasting and colorful leaves. Understanding the mode of inheritance for caladium leaf characteristics is critical for plant breeders to select appropriate parents, predict progeny performance, estimate breeding population sizes needed, and increase breeding efficiencies. This study was conducted to determine the mode of inheritance of two leaf background colors (lemon and green) in caladium and to understand their relationships with four other important leaf characteristics including leaf shape, main vein color, spotting, and rugosity. Seven caladium cultivars and three breeding lines were used as parents in 19 crosses, and their progeny were phenotyped for segregation of leaf traits. Results showed that the two leaf background colors are controlled by a single nuclear locus, with two alleles, LEM and lem, which control the dominant lemon and the recessive green leaf background color, respectively. The lemon-colored cultivar ‘Miss Muffet’ and breeding lines UF-52 and UF-53 have a heterozygous genotype LEMlem. Chi-square tests showed that the leaf background color locus LEM is independent from the leaf shape locus F, but is tightly linked to three loci (S, V and RLF) controlling leaf spotting, main vein color, and rugosity in caladium. A linkage map that consists of four loci controlling major caladium leaf characteristics and extends ~15 cM was developed based on the observed recombination frequencies. This is the first report on the mode of inheritance of leaf background colors in caladium and in the Araceae family. The information gained in this study will be very useful for caladium breeding and study of the inheritance of leaf colors in other ornamental aroids, an important group of ornamental plants in the world. PMID:28101369

  3. Changes of leaf morphological, anatomical structure and carbon isotope ratio with the height of the Wangtian tree (Parashorea chinensis) in Xishuangbanna, China.

    Science.gov (United States)

    He, Chun-Xia; Li, Ji-Yue; Zhou, Ping; Guo, Ming; Zheng, Quan-Shui

    2008-02-01

    Leaf morphological and anatomical structure and carbon isotope ratio (delta13C) change with increasing tree height. To determine how tree height affects leaf characteristics, we measured the leaf area, specific leaf mass (ratio of leaf mass to leaf area [LMA]), thickness of the total leaf, cuticle, epidermis, palisade and sponge mesophyll, stomata traits and delta13C at different heights of Parashorea chinensis with methods of light and scanning electron microscopy (SEM) and isotope-ratio mass spectrometry. The correlation and stepwise regression between tree height and leaf structure traits were carried out with SPSS software. The results showed that leaf structures and delta13C differed significantly along the tree height gradient. The leaf area, thickness of sponge mesophyll and size of stomata decreased with increasing height, whereas the thickness of lamina, palisade mesophyll, epidermis, and cuticle, ratios of palisade to spongy thickness, density of stomata and vascular bundles, LMA and delta13C increased with tree height. Tree height showed a significant relationship with all leaf indices and the most significant relationship was with epidermis thickness, leaf area, cuticle thickness, delta13C. The delta13C value showed a significantly positive relationship with LMA (R = 0.934). Our results supported the hypothesis that the leaf structures exhibited more xeromorphic characteristics with the increasing gradient of tree height.

  4. Changes of Leaf Morphological, Anatomical Structure and Carbon Isotope Ratio with the Height of the Wangtian Tree (Parashorea chinensis) in Xishuangbanna, China

    Institute of Scientific and Technical Information of China (English)

    Chun-Xia He; Ji-Yue Li; Ping Zhou; Ming Guo; Quan-Shui Zheng

    2008-01-01

    Leaf morphological and anatomical structure and carbon isotope ratio (δ13C) change with increasing tree height. To determine how tree height affects leaf characteristics, we measured the leaf area, specific leaf mass (ratio of leaf mass to leaf area [LMA]), thickness of the total leaf, cuticle, epidermis, palisade and sponge mesophyll, stomata traits and δ13C at different heights of Parashorea chinensis with methods of light and scanning electron microscopy (SEM) and isotope-ratio mass spectrometry. The correlation and stepwise regression between tree height and leaf structure traits were carried out with SPSS software. The results showed that leaf structures and δ13C differed significantly along the tree height gradient. The leaf area, thickness of sponge mesophyll and size of stomata decreased with increasing height, whereas the thickness of lamina, palisade mesophyll, epidermis, and cuticle, ratios of palisade to spongy thickness, density of stomata and vascular bundles, LMA and δ13C increased with tree height. Tree height showed a significant relationship with all leaf Indices and the most significant relationship was with epidermis thickness, leaf area, cuticle thickness, δ13C. The δ13C value showed a significantly positive relationship with LMA (R = 0.934). Our results supported the hypothesis that the leaf structures exhibited more xeromorphic characteristics with the increasing gradient of tree height.

  5. Variation in species-level plant functional traits over wetland indicator status categories

    Science.gov (United States)

    McCoy-Sulentic, Miles E.; Kolb, Thomas E.; Merritt, David M.; Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel A.

    2017-01-01

    Wetland indicator status (WIS) describes the habitat affinity of plant species and is used in wetland delineations and resource inventories. Understanding how species-level functional traits vary across WIS categories may improve designations, elucidate mechanisms of adaptation, and explain habitat optima and niche. We investigated differences in species-level traits of riparian flora across WIS categories, extending their application to indicate hydrologic habitat. We measured or compiled data on specific leaf area (SLA), stem specific gravity (SSG), seed mass, and mature height of 110 plant species that occur along the Colorado River in Grand Canyon, Arizona. Additionally, we measured leaf δ13C, δ15N, % carbon, % nitrogen, and C/N ratio of 56 species with C3 photosynthesis. We asked the following: (i) How do species-level traits vary over WIS categories? (ii) Does the pattern differ between herbaceous and woody species? (iii) How well do multivariate traits define WIS categories? (iv) Which traits are correlated? The largest trait differences among WIS categories for herbaceous species occurred for SSG, seed mass, % leaf carbon and height, and for woody species occurred for height, SSG, and δ13C. SSG increased and height decreased with habitat aridity for both woody and herbaceous species. The δ13C and hence water use efficiency of woody species increased with habitat aridity. Water use efficiency of herbaceous species increased with habitat aridity via greater occurrence of C4 grasses. Multivariate trait assemblages differed among WIS categories. Over all species, SLA was correlated with height, δ13C, % leaf N, and C/N; height was correlated with SSG and % leaf C; SSG was correlated with % leaf C. Adaptations of both herbaceous and woody riparian species to wet, frequently inundated habitats include low-density stem tissue. Adaptations to drier habitats in the riparian zone include short, high-density cavitation-resistant stem tissue, and high water use

  6. Traits traded off

    NARCIS (Netherlands)

    Rueffler, Claus

    2006-01-01

    The course of evolution is restricted by constraints. A special type of constraint is a trade-off where different traits are negatively correlated. In this situation a mutant type that shows an improvement in one trait suffers from a decreased performance through another trait. In a fixed fitness la

  7. LEAF MICROMOPHOMETRY OF PALICOUREA RIGIDA KUNTH. (RUBIACEAE FROM BRAZILIAN CERRADO AND CAMPO RUPESTRE ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    Manuel Losada Gavilanes

    2016-06-01

    Full Text Available The objective of this work was to evaluate qualitative and quantitative leaf anatomical traits of Palicourea rigida Kunth. (Rubiaceae species occurring in the Brazilian Cerrado and Campo Rupestre ecosystems. Anatomical analysis was performed in fresh or fixed leaves processed with usual plant microtechnique. Leaves showed uniseriate epidermis in petiole and leaf blade which contains uniseriate nonglandular tricomes (tector type occurring only over the vascular bundles. Likewise, paracytic stomata were found only in abaxial side of the leaf surface. The mesophyll contains uniseriate palisade parenchyma and multiseriate spongy parenchyma (nine layers which showed cells with different morphology and size. Crystal idoblasts of different types were observed in both the petiole and leaf blade. Collateral vascular bundles were found both in the petiole and leaf blade. Leaf venation type was pinnate, campylodromous or brochydodromous. The micromorphometric analysis showed significant differences from plants of different environments for all leaf characteristics and Cerrado plants showed higher means for all evaluated traits. Therefore, the influence of environments may had modulated morphological responses in P. rigida, since no difference was found in the type or distribution of leaf tissues in Cerrado or Campo Rupestre.

  8. Patterns of leaf morphology and leaf N content in relation to winter temperatures in three evergreen tree species

    Science.gov (United States)

    Mediavilla, Sonia; Gallardo-López, Victoria; González-Zurdo, Patricia; Escudero, Alfonso

    2012-09-01

    The competitive equilibrium between deciduous and perennial species in a new scenario of climate change may depend closely on the productivity of leaves along the different seasons of the year and on the morphological and chemical adaptations required for leaf survival during the different seasons. The aim of the present work was to analyze such adaptations in the leaves of three evergreen species ( Quercus ilex, Q. suber and Pinus pinaster) and their responses to between-site differences in the intensity of winter harshness. We explore the hypothesis that the harshness of winter would contribute to enhancing the leaf traits that allow them to persist under conditions of stress. The results revealed that as winter harshness increases a decrease in leaf size occurs in all three species, together with an increase in the content of nitrogen per unit leaf area and a greater leaf mass per unit area, which seems to be achieved only through increased thickness, with no associated changes in density. P. pinaster was the species with the most intense response to the harshening of winter conditions, undergoing a more marked thickening of its needles than the two Quercus species. Our findings thus suggest that lower winter temperatures involve an increase in the cost of leaf production of evergreen species, which must be taken into account in the estimation of the final cost and benefit balance of evergreens. Such cost increases would be more pronounced for those species that, like P. pinaster, show a stronger response to the winter cold.

  9. Chemical constituents of Cinnamomum septentrionale leaf litter and its allelopathic activity on the growth of maize (Zea mays).

    Science.gov (United States)

    Yang, Shanshan; Hu, Hongling; Hu, Tingxing; Wang, Qian; Ye, Mao; Luo, Jie; Peng, Yong; Zhang, Ruyi

    2017-06-01

    A pot experiment was conducted to study the effect of decomposing Cinnamomum septentrionale leaf litter on the growth of maize. In this study, the morphological traits of maize were significantly inhibited when the leaf litter amount reached or exceeded 40 g per pot; Furthermore, during the early growth stage or with a large amount of litter addition, the pigment contents were inhibited by C. septentrionale leaf litter. Gas chromatography-mass spectrometry was used to determine the volatile substances of leaf litter and 34 compounds were identified, several of which were reported to be phytotoxic. In conclusion, the leaf litter of C. septentrionale showed a strong allelopathic effect on the growth of maize. Thus, it is better to avoid the growing of maize under or near the C. septentrionale plantation unless the leaf litter could be eliminated in time or other effective leaf litter processing methods could be implemented.

  10. Asian Eocene monsoons as revealed by leaf architectural signatures

    Science.gov (United States)

    Spicer, Robert A.; Yang, Jian; Herman, Alexei B.; Kodrul, Tatiana; Maslova, Natalia; Spicer, Teresa E. V.; Aleksandrova, Galina; Jin, Jianhua

    2016-09-01

    The onset and development of the Asian monsoon systems is a topic that has attracted considerable research effort but proxy data limitations, coupled with a diversity of definitions and metrics characterizing monsoon phenomena, have generated much debate. Failure of geological proxies to yield metrics capable of distinguishing between rainfall seasonality induced by migrations of the Inter-tropical Convergence Zone (ITCZ) from that attributable to topographically modified seasonal pressure reversals has frustrated attempts to understand mechanisms underpinning monsoon development and dynamics. Here we circumvent the use of such single climate parameter metrics in favor of detecting directly the distinctive attributes of different monsoon regimes encoded in leaf fossils. Leaf form adapts to the prevailing climate, particularly under the extreme seasonal stresses imposed by monsoons, so it is likely that fossil leaves carry a unique signature of past monsoon regimes. Leaf form trait spectra obtained from fossils from Eocene basins in southern China were compared with those seen in modern leaves growing under known climate regimes. The fossil leaf trait spectra, including those derived from previously published fossil floras from northwestern India, were most similar to those found in vegetation exposed to the modern Indonesia-Australia Monsoon (I-AM), which is largely a product of seasonal migrations of the ITCZ. The presence of this distinctive leaf physiognomic signature suggests that although a monsoon climate existed in Eocene time across southern Asia the characteristics of the modern topographically-enhanced South Asia Monsoon had yet to develop. By the Eocene leaves in South Asia had become well adapted to an I-AM type regime across many taxa and points to the existence of a pervasive monsoon climate prior to the Eocene. No fossil trait spectra typical of exposure to the modern East Asia monsoon were seen, suggesting the effects of this system in southern

  11. Examining variation in the leaf mass per area of dominant species across two contrasting tropical gradients in light of community assembly.

    Science.gov (United States)

    Neyret, Margot; Bentley, Lisa Patrick; Oliveras, Imma; Marimon, Beatriz S; Marimon-Junior, Ben Hur; Almeida de Oliveira, Edmar; Barbosa Passos, Fábio; Castro Ccoscco, Rosa; Dos Santos, Josias; Matias Reis, Simone; Morandi, Paulo S; Rayme Paucar, Gloria; Robles Cáceres, Arturo; Valdez Tejeira, Yolvi; Yllanes Choque, Yovana; Salinas, Norma; Shenkin, Alexander; Asner, Gregory P; Díaz, Sandra; Enquist, Brian J; Malhi, Yadvinder

    2016-08-01

    Understanding variation in key functional traits across gradients in high diversity systems and the ecology of community changes along gradients in these systems is crucial in light of conservation and climate change. We examined inter- and intraspecific variation in leaf mass per area (LMA) of sun and shade leaves along a 3330-m elevation gradient in Peru, and in sun leaves across a forest-savanna vegetation gradient in Brazil. We also compared LMA variance ratios (T-statistics metrics) to null models to explore internal (i.e., abiotic) and environmental filtering on community structure along the gradients. Community-weighted LMA increased with decreasing forest cover in Brazil, likely due to increased light availability and water stress, and increased with elevation in Peru, consistent with the leaf economic spectrum strategy expected in colder, less productive environments. A very high species turnover was observed along both environmental gradients, and consequently, the first source of variation in LMA was species turnover. Variation in LMA at the genus or family levels was greater in Peru than in Brazil. Using dominant trees to examine possible filters on community assembly, we found that in Brazil, internal filtering was strongest in the forest, while environmental filtering was observed in the dry savanna. In Peru, internal filtering was observed along 80% of the gradient, perhaps due to variation in taxa or interspecific competition. Environmental filtering was observed at cloud zone edges and in lowlands, possibly due to water and nutrient availability, respectively. These results related to variation in LMA indicate that biodiversity in species rich tropical assemblages may be structured by differential niche-based processes. In the future, specific mechanisms generating these patterns of variation in leaf functional traits across tropical environmental gradients should be explored.

  12. Differences in functional traits between invasive and native Amaranthus species under different forms of N deposition

    Science.gov (United States)

    Wang, Congyan; Zhou, Jiawei; Liu, Jun; Jiang, Kun

    2017-08-01

    Differences in functional traits between invasive and native plant species are believed to determine the invasion success of the former. Increasing amounts of anthropogenic nitrogen (N) are continually deposited into natural ecosystems, which may change the relative occurrence of the different N deposition forms (such as NH4-N, NO3-N, and CO(NH2)2-N) naturally deposited. Under high N deposition scenarios, some invasive species may grow faster, gaining advantage over native species. In a greenhouse experiment, we grew invasive and native Amaranthus species from seed both alone and in competition under simulated N enriched environments with different forms of N over 3 months. Then, we measured different leaf traits (i.e., plant height, leaf length, leaf width, leaf shape index, specific leaf area (SLA), and leaf chlorophyll and N concentrations). Results showed that the competition intensity between A. retroflexus and A. tricolor decreased under N deposition. This may be due to the large functional divergence between A. retroflexus and A. tricolor under simulated N deposition. Phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus were significantly lower than in A. tricolor. The lower range of phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may indicate a fitness cost for plastic functional traits under adverse environments. The restricted phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may also stabilize leaf construction costs and the growth rate. Meanwhile, the two Amaranthus species possessed greater plasticity in leaf N concentration under NO3-N fertilization, which enhanced their competitiveness.

  13. Global variability in leaf respiration in relation to climate, plant functional types and leaf traits

    Science.gov (United States)

    Owen K. Atkin; Keith J. Bloomfield; Peter B. Reich; Mark G. Tjoelker; Gregory P. Asner; Damien Bonal; Gerhard Bonisch; Matt G. Bradford; Lucas A. Cernusak; Eric G. Cosio; Danielle Creek; Kristine Y. Crous; Tomas F. Domingues; Jeffrey S. Dukes; John J. G. Egerton; John R. Evans; Graham D. Farquhar; Nikolaos M. Fyllas; Paul P. G. Gauthier; Emanuel Gloor; Teresa E. Gimeno; Kevin L. Griffin; Rossella Guerrieri; Mary A. Heskel; Chris Huntingford; Franc_oise Yoko Ishida; Jens Kattge; Hans Lambers; Michael J. Liddell; Jon Lloyd; Christopher H. Lusk; Roberta E. Martin; Ayal P. Maksimov; Trofim C. Maximov; Yadvinder Malhi; Belinda E. Medlyn; Patrick Meir; Lina M. Mercado; Nicholas Mirotchnick; Desmond Ng; Ulo Niinemets; Odhran S. O’Sullivan; Oliver L. Phillips; Lourens Poorter; Pieter Poot; I. Colin Prentice; Norma Salinas; Lucy M. Rowland; Michael G. Ryan; Stephen Sitch; Martijn Slot; Nicholas G. Smith; Matthew H. Turnbull; Mark C. VanderWel; Fernando Valladares; Erik J. Veneklaas; Lasantha K. Weerasinghe; Christian Wirth; Ian J. Wright; Kirk R. Wythers; Jen Xiang; Shuang Xiang; Joana Zaragoza-Castells

    2015-01-01

    A challenge for the development of terrestrial biosphere models (TBMs) and associated land surface components of Earth system models (ESMs) is improving representation of carbon (C) exchange between terrestrial plants and the atmosphere, and incorporating biological variation arising from diversity in plant functional types (PFTs) and climate (Sitch et al.,...

  14. phenoVein - A tool for leaf vein segmentation and analysis

    OpenAIRE

    Bühler, J.; Rishmawi, L.; Pflugfelder, D.; Huber, G; Scharr, H.; Hülskamp, M; Koornneef, M.; Schurr, U; Jahnke, S.

    2015-01-01

    Precise measurements of leaf vein traits are an important aspect of plant phenotyping for ecological and genetic research. Here, we present a powerful and user-friendly image analysis tool named phenoVein. It is dedicated to automated segmenting and analyzing of leaf veins in images acquired with different imaging modalities (microscope, macrophotography, etc.), including options for comfortable manual correction. Advanced image filtering emphasizes veins from the background and compensates f...

  15. phenoVein - A software tool for leaf vein segmentation and analysis

    OpenAIRE

    Bühler, Jonas; Rishmawi, Louai; Pflugfelder, Daniel; Huber, Gregor; Scharr, Hanno; Hülskamp, Martin; Koornneef, Maarten; SCHURR, ULRICH; Jahnke, Siegfried

    2015-01-01

    phenoVein is a software tool dedicated to automated segmenting and analyzing images of leaf veins. It includes comfortable manual correction features. Advanced image filtering automatically emphasizes veins from background and compensates for local brightness inhomogeneities. Phenotypical leaf vein traits being calculated are total vein density, vein lengths and widths and skeleton graph statistics. For determination of vein widths, a model based vein edge estimation approach has been impleme...

  16. Leaf anatomy and photosynthesis

    NARCIS (Netherlands)

    Berghuijs, H.N.C.

    2016-01-01

    Keywords: CO2 diffusion, C3 photosynthesis, mesophyll conductance, mesophyll resistance, re-assimilation, photorespiration, respiration, tomato Herman Nicolaas Cornelis Berghuijs (2016). Leaf anatomy and photosynthesis; unravelling the CO2 diffusion pathway in C3 leaves. PhD thesis. Wageningen Unive

  17. Light drives vertical gradients of leaf morphology in a sugar maple (Acer saccharum) forest.

    Science.gov (United States)

    Coble, Adam P; Cavaleri, Molly A

    2014-02-01

    Leaf mass per area (LMA, g m(-2)) is an essential trait for modeling canopy function due to its strong association with photosynthesis, respiration and leaf nitrogen. Leaf mass per area, which is influenced by both leaf thickness and density (LMA = thickness × density), generally increases from the bottom to the top of tree canopies, yet the mechanisms behind this universal pattern are not yet resolved. For decades, the light environment was assumed to be the most influential driver of within-canopy variation in LMA, yet recent evidence has shown hydrostatic gradients to be more important in upper canopy positions, especially in tall evergreen trees in temperate and tropical forests. The aim of this study was to disentangle the importance of various environmental drivers on vertical LMA gradients in a mature sugar maple (Acer saccharum Marshall) forest. We compared LMA, leaf density and leaf thickness relationships with height, light and predawn leaf water potential (ΨPre) within a closed and an exposed canopy to assess leaf morphological traits at similar heights but different light conditions. Contrary to our expectations and recent findings in the literature, we found strong evidence that light was the primary driver of vertical gradients in leaf morphology. At similar heights (13-23 m), LMA was greater within the exposed canopy than the closed canopy, and light had a stronger influence over LMA compared with ΨPre. Light also had a stronger influence over both leaf thickness and density compared with ΨPre; however, the increase in LMA within both canopy types was primarily due to increasing leaf thickness with increasing light availability. This study provides strong evidence that canopy structure and crown exposure, in addition to height, should be considered as a parameter for determining vertical patterns in LMA and modeling canopy function.

  18. Predicting plants -modeling traits as a function of environment

    Science.gov (United States)

    Franklin, Oskar

    2016-04-01

    A central problem in understanding and modeling vegetation dynamics is how to represent the variation in plant properties and function across different environments. Addressing this problem there is a strong trend towards trait-based approaches, where vegetation properties are functions of the distributions of functional traits rather than of species. Recently there has been enormous progress in in quantifying trait variability and its drivers and effects (Van Bodegom et al. 2012; Adier et al. 2014; Kunstler et al. 2015) based on wide ranging datasets on a small number of easily measured traits, such as specific leaf area (SLA), wood density and maximum plant height. However, plant function depends on many other traits and while the commonly measured trait data are valuable, they are not sufficient for driving predictive and mechanistic models of vegetation dynamics -especially under novel climate or management conditions. For this purpose we need a model to predict functional traits, also those not easily measured, and how they depend on the plants' environment. Here I present such a mechanistic model based on fitness concepts and focused on traits related to water and light limitation of trees, including: wood density, drought response, allocation to defense, and leaf traits. The model is able to predict observed patterns of variability in these traits in relation to growth and mortality, and their responses to a gradient of water limitation. The results demonstrate that it is possible to mechanistically predict plant traits as a function of the environment based on an eco-physiological model of plant fitness. References Adier, P.B., Salguero-Gómez, R., Compagnoni, A., Hsu, J.S., Ray-Mukherjee, J., Mbeau-Ache, C. et al. (2014). Functional traits explain variation in plant lifehistory strategies. Proc. Natl. Acad. Sci. U. S. A., 111, 740-745. Kunstler, G., Falster, D., Coomes, D.A., Hui, F., Kooyman, R.M., Laughlin, D.C. et al. (2015). Plant functional traits

  19. Heterochrony underpins natural variation in Cardamine hirsuta leaf form

    Science.gov (United States)

    Cartolano, Maria; Pieper, Bjorn; Lempe, Janne; Tattersall, Alex; Huijser, Peter; Tresch, Achim; Darrah, Peter R.; Hay, Angela; Tsiantis, Miltos

    2015-01-01

    A key problem in biology is whether the same processes underlie morphological variation between and within species. Here, by using plant leaves as an example, we show that the causes of diversity at these two evolutionary scales can be divergent. Some species like the model plant Arabidopsis thaliana have simple leaves, whereas others like the A. thaliana relative Cardamine hirsuta bear complex leaves comprising leaflets. Previous work has shown that these interspecific differences result mostly from variation in local tissue growth and patterning. Now, by cloning and characterizing a quantitative trait locus (QTL) for C. hirsuta leaf shape, we find that a different process, age-dependent progression of leaf form, underlies variation in this trait within species. This QTL effect is caused by cis-regulatory variation in the floral repressor ChFLC, such that genotypes with low-expressing ChFLC alleles show both early flowering and accelerated age-dependent changes in leaf form, including faster leaflet production. We provide evidence that this mechanism coordinates leaf development with reproductive timing and may help to optimize resource allocation to the next generation. PMID:26243877

  20. Leaf structural diversity is related to hydraulic capacity in tropical rain forest trees.

    Science.gov (United States)

    Sack, Lawren; Frole, Kristen

    2006-02-01

    The hydraulic resistance of the leaf (R1) is a major bottleneck in the whole plant water transport pathway and may thus be linked with the enormous variation in leaf structure and function among tropical rain forest trees. A previous study found that R1 varied by an order of magnitude across 10 tree species of Panamanian tropical lowland rain forest. Here, correlations were tested between R1 and 24 traits relating to leaf venation and mesophyll structure, and to gross leaf form. Across species, R1 was related to both venation architecture and mesophyll structure. R1 was positively related to the theoretical axial resistivity of the midrib, determined from xylem conduit numbers and dimensions, and R1 was negatively related to venation density in nine of 10 species. R1 was also negatively related to both palisade mesophyll thickness and to the ratio of palisade to spongy mesophyll. By contrast, numerous leaf traits were independent of R1, including area, shape, thickness, and density, demonstrating that leaves can be diverse in gross structure without intrinsic trade-offs in hydraulic capacity. Variation in both R1-linked and R1-independent traits related strongly to regeneration irradiance, indicating the potential importance of both types of traits in establishment ecology.

  1. The Hidden Complexity of Mendelian Traits across Natural Yeast Populations

    Directory of Open Access Journals (Sweden)

    Jing Hou

    2016-07-01

    Full Text Available Mendelian traits are considered to be at the lower end of the complexity spectrum of heritable phenotypes. However, more than a century after the rediscovery of Mendel’s law, the global landscape of monogenic variants, as well as their effects and inheritance patterns within natural populations, is still not well understood. Using the yeast Saccharomyces cerevisiae, we performed a species-wide survey of Mendelian traits across a large population of isolates. We generated offspring from 41 unique parental pairs and analyzed 1,105 cross/trait combinations. We found that 8.9% of the cases were Mendelian. Further tracing of causal variants revealed background-specific expressivity and modified inheritances, gradually transitioning from Mendelian to complex traits in 30% of the cases. In fact, when taking into account the natural population diversity, the hidden complexity of traits could be substantial, confounding phenotypic predictability even for simple Mendelian traits.

  2. Leaf photosynthetic rate of tropical ferns is evolutionarily linked to water transport capacity.

    Science.gov (United States)

    Zhang, Shi-Bao; Sun, Mei; Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

    2014-01-01

    Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns.

  3. Plant morphometric traits and climate gradients in northern China: a meta-analysis using quadrat and flora data.

    Science.gov (United States)

    Meng, Ting-Ting; Ni, Jian; Harrison, Sandy P

    2009-11-01

    The collection of field data on plant traits is time consuming and this makes it difficult to examine changing patterns of traits along large-scale climate gradients. The present study tests whether trait information derived from regional floras can be used in conjunction with pre-existing quadrat data on species presence to derive meaningful relationships between specific morphometric traits and climate. Quadrat records were obtained for 867 species in 404 sites from northern China (38-49 degrees N, 82-132 degrees E) together with information on the presence/absence of key traits from floras. Bioclimate parameters for each site were calculated using the BIOME3 model. Principal component analysis and correlation analysis were conducted to determine the most important climate factors. The Akaike Information Criterion was used to select the best relationship between each trait and climate. Canonical correspondence analysis was used to explore the relationships between climate and trait occurrence. The changing abundance of life form, leaf type, phenology, photosynthetic pathway, leaf size and several other morphometric traits are determined by gradients in plant-available moisture (as measured by the ratio of actual to potential evapotranspiration: alpha), growing-season temperature (as measured by growing degree-days on a 0 degrees base: GDD(0)) or a combination of these. Different plant functional types (PFTs, as defined by life form, leaf type and phenology) reach maximum abundance in distinct areas of this climate space: for example, evergreen trees occur in the coldest, wettest environments (GDD(0) 0.38), and deciduous scale-leaved trees occur in drier, warmer environments than deciduous broad-leaved trees. Most leaf-level traits show similar relationships with climate independently of PFT: for example, leaf size in all PFTs increases as the environment becomes wetter and cooler. However, some traits (e.g. petiole length) display different relationships with

  4. Can adaptive modulation of traits to urban environments facilitate Ricinus communis L. invasiveness?

    Science.gov (United States)

    Goyal, Neha; Pardha-Saradhi, P; Sharma, Gyan P

    2014-11-01

    This paper addresses the phenotypic variation among Ricinus communis L. populations in four urban habitat types (road verges, garbage dumps, construction debris, and natural area) in Delhi, India, by evaluating important traits such as plant height, basal circumference, seeds per plant, seed size, seed weight, specific leaf area, and reproductive index. An important biochemical marker, proline, considered as a good plant performance indicator under stress was also quantified in leaves of R. communis to evaluate its response in different habitats. Interestingly, the species showed significant variation in plant height, specific leaf area, seed size, seed weight, and leaf proline content in different habitat types. Leaf proline content was positively related to plant height, specific leaf area, and seed size while negatively related to the total number of seeds/plant. Interestingly, reproductive index, calculated as a ratio of the total number of seeds to the plant height also showed a negative relation with leaf proline content. Results indicated that R. communis exhibits adaptive modulation of growth, reproductive traits, and leaf proline content in various urban habitats which contributes to invasiveness, range expansion, and establishment of the species. The study also gives evidence of how morphological and physiological traits could directly affect invasiveness of R. communis.

  5. FishTraits Database

    Science.gov (United States)

    Angermeier, Paul L.; Frimpong, Emmanuel A.

    2009-01-01

    The need for integrated and widely accessible sources of species traits data to facilitate studies of ecology, conservation, and management has motivated development of traits databases for various taxa. In spite of the increasing number of traits-based analyses of freshwater fishes in the United States, no consolidated database of traits of this group exists publicly, and much useful information on these species is documented only in obscure sources. The largely inaccessible and unconsolidated traits information makes large-scale analysis involving many fishes and/or traits particularly challenging. FishTraits is a database of >100 traits for 809 (731 native and 78 exotic) fish species found in freshwaters of the conterminous United States, including 37 native families and 145 native genera. The database contains information on four major categories of traits: (1) trophic ecology, (2) body size and reproductive ecology (life history), (3) habitat associations, and (4) salinity and temperature tolerances. Information on geographic distribution and conservation status is also included. Together, we refer to the traits, distribution, and conservation status information as attributes. Descriptions of attributes are available here. Many sources were consulted to compile attributes, including state and regional species accounts and other databases.

  6. Continuous within-plant variation as a source of intraspecific functional diversity: Patterns, magnitude, and genetic correlates of leaf variability in Helleborus foetidus (Ranunculaceae)

    National Research Council Canada - National Science Library

    Herrera, Carlos M; Medrano, Mónica; Bazaga, Pilar

    2015-01-01

    .... For the perennial Helleborus foetidus, we measured functional leaf traits to quantify the contribution of within-plant variation to intraspecific functional variance and evaluate whether within-plant...

  7. Carbon dynamics in aboveground biomass of co-dominant plant species: related rather to leaf life span than to species

    Science.gov (United States)

    Ostler, Ulrike; Schleip, Inga; Lattanzi, Fernando A.; Schnyder, Hans

    2016-04-01

    This study investigates the role of individual organisms in whole ecosystem carbon (C) fluxes. It is currently unknown if different plant community members share the same or different kinetics of C pools in aboveground biomass, thereby adding (or not) variability to the first steps in ecosystem C cycling. We assessed the residence times in metabolic and non-metabolic (or structural) C pools and the allocation pattern of assimilated C in aboveground plant parts of four co-existing, co-dominant species from different functional groups in a temperate grassland community. For this purpose continuous, 14-16 day long 13CO2/12CO2-labeling experiments were performed in Sept. 2006, May 2007 and Sept. 2007, and the tracer kinetics were analysed with compartmental modeling. In all experimental periods, the species shared vastly similar residence times in metabolic C (5-8 d). In contrast, the residence times in non-metabolic C ranged from 20 to 58 d (except one outlier) and the fraction of fixed C allocated to the non-metabolic pool from 7 to 45%. These variations in non-metabolic C kinetics were not systematically associated with species or experimental periods, but exhibited close relationships with (independent estimates of) leaf life span, particularly in the grasses. This adds new meaning to leaf life span as a functional trait in the leaf and plant economics spectrum and its implication for C cycle studies in grassland and also forest systems. As the four co-dominant species accounted for ~80% of total community shoot biomass, we should also expect that the observed similarities in pool kinetics and allocation will scale up to similar relationships at the community level.

  8. Evolutionary changes in correlations among functional traits in Ceanothus in response to Mediterranean conditions

    Directory of Open Access Journals (Sweden)

    T. M. Hardig

    2006-06-01

    Full Text Available Ceanothus is a widely speciated genus with two sections that differ markedly in size, patterns of biomass allocation and reproductive strategies. On greenhouse-grown seedlings we tested whether divergence occurred in single traits or in suites of traits, and whether taxonomic affinity or the ability to fix nitrogen (N influenced the relationships among functional traits. Species of the subgenus Cerastes differed from species in the subgenus Ceanothus in the following characteristics: reproduction by seed rather than primarily resprouting, high rates of photosynthesis and high stomatal conductance, thick leaves, low root allocation, and high leaf allocation. Correlations of traits across the entire genus showed positive correlations among traits that maximize photosynthesis and tradeoffs between root allocation and carbon gain patterns frequently observed in other broad taxonomic comparisons. Trait correlations differed between the two subgenera (divergence in allocation-photosynthesis tradeoffs in Ceanothus and divergence of growth-related traits in Cerastes. Similarly, N-fixers, which were distributed broadly between the two subgenera, differed in trait correlations (primarily among traits related to photosynthesis from non-fixers (primarily among traits related to growth and allocation. These results indicate that 1 divergence in genus Ceanothus was associated with changes in entire suite of traits, rather than independent changes in individual traits and 2 evolution occurring under different environmental or nutritional circumstances alters the suites of traits exhibited by plants.

  9. Genome Wide Single Locus Single Trait, Multi-Locus and Multi-Trait Association Mapping for Some Important Agronomic Traits in Common Wheat (T. aestivum L.).

    Science.gov (United States)

    Jaiswal, Vandana; Gahlaut, Vijay; Meher, Prabina Kumar; Mir, Reyazul Rouf; Jaiswal, Jai Prakash; Rao, Atmakuri Ramakrishna; Balyan, Harindra Singh; Gupta, Pushpendra Kumar

    2016-01-01

    Genome wide association study (GWAS) was conducted for 14 agronomic traits in wheat following widely used single locus single trait (SLST) approach, and two recent approaches viz. multi locus mixed model (MLMM), and multi-trait mixed model (MTMM). Association panel consisted of 230 diverse Indian bread wheat cultivars (released during 1910-2006 for commercial cultivation in different agro-climatic regions in India). Three years phenotypic data for 14 traits and genotyping data for 250 SSR markers (distributed across all the 21 wheat chromosomes) was utilized for GWAS. Using SLST, as many as 213 MTAs (p ≤ 0.05, 129 SSRs) were identified for 14 traits, however, only 10 MTAs (~9%; 10 out of 123 MTAs) qualified FDR criteria; these MTAs did not show any linkage drag. Interestingly, these genomic regions were coincident with the genomic regions that were already known to harbor QTLs for same or related agronomic traits. Using MLMM and MTMM, many more QTLs and markers were identified; 22 MTAs (19 QTLs, 21 markers) using MLMM, and 58 MTAs (29 QTLs, 40 markers) using MTMM were identified. In addition, 63 epistatic QTLs were also identified for 13 of the 14 traits, flag leaf length (FLL) being the only exception. Clearly, the power of association mapping improved due to MLMM and MTMM analyses. The epistatic interactions detected during the present study also provided better insight into genetic architecture of the 14 traits that were examined during the present study. Following eight wheat genotypes carried desirable alleles of QTLs for one or more traits, WH542, NI345, NI170, Sharbati Sonora, A90, HW1085, HYB11, and DWR39 (Pragati). These genotypes and the markers associated with important QTLs for major traits can be used in wheat improvement programs either using marker-assisted recurrent selection (MARS) or pseudo-backcrossing method.

  10. Genome Wide Single Locus Single Trait, Multi-Locus and Multi-Trait Association Mapping for Some Important Agronomic Traits in Common Wheat (T. aestivum L..

    Directory of Open Access Journals (Sweden)

    Vandana Jaiswal

    Full Text Available Genome wide association study (GWAS was conducted for 14 agronomic traits in wheat following widely used single locus single trait (SLST approach, and two recent approaches viz. multi locus mixed model (MLMM, and multi-trait mixed model (MTMM. Association panel consisted of 230 diverse Indian bread wheat cultivars (released during 1910-2006 for commercial cultivation in different agro-climatic regions in India. Three years phenotypic data for 14 traits and genotyping data for 250 SSR markers (distributed across all the 21 wheat chromosomes was utilized for GWAS. Using SLST, as many as 213 MTAs (p ≤ 0.05, 129 SSRs were identified for 14 traits, however, only 10 MTAs (~9%; 10 out of 123 MTAs qualified FDR criteria; these MTAs did not show any linkage drag. Interestingly, these genomic regions were coincident with the genomic regions that were already known to harbor QTLs for same or related agronomic traits. Using MLMM and MTMM, many more QTLs and markers were identified; 22 MTAs (19 QTLs, 21 markers using MLMM, and 58 MTAs (29 QTLs, 40 markers using MTMM were identified. In addition, 63 epistatic QTLs were also identified for 13 of the 14 traits, flag leaf length (FLL being the only exception. Clearly, the power of association mapping improved due to MLMM and MTMM analyses. The epistatic interactions detected during the present study also provided better insight into genetic architecture of the 14 traits that were examined during the present study. Following eight wheat genotypes carried desirable alleles of QTLs for one or more traits, WH542, NI345, NI170, Sharbati Sonora, A90, HW1085, HYB11, and DWR39 (Pragati. These genotypes and the markers associated with important QTLs for major traits can be used in wheat improvement programs either using marker-assisted recurrent selection (MARS or pseudo-backcrossing method.

  11. Arabidopsis onset of leaf death mutants identify a regulatory pathway controlling leaf senescence

    NARCIS (Netherlands)

    Jing, Hai-Chun; Sturre, Marcel J.G.; Hille, Jacques; Dijkwel, Paul P.

    2002-01-01

    The onset of leaf senescence is controlled by leaf age and ethylene can promote leaf senescence within a specific age window. We exploited the interaction between leaf age and ethylene and isolated mutants with altered leaf senescence that are named as onset of leaf death (old) mutants. Early leaf

  12. Leaf hydraulic vulnerability influences species' bioclimatic limits in a diverse group of woody angiosperms.

    Science.gov (United States)

    Blackman, Chris J; Brodribb, Tim J; Jordan, Gregory J

    2012-01-01

    The ability of plants to maintain water flow through leaves under water stress-induced tension (assessed as the leaf hydraulic vulnerability; P50(leaf)) is intimately linked with survival. We examined the significance of P50(leaf) as an adaptive trait in influencing the dry-end distributional limits of cool temperate woody angiosperm species. We also examined differences in within-site variability in P50(leaf) between two high-rainfall montane rainforest sites in Tasmania and Peru, respectively. A significant relationship between P50(leaf) and the 5th percentile of mean annual rainfall across each species distribution was found in Tasmania, suggesting that P50(leaf) influences species climatic limits. Furthermore, a strong correlation between P50(leaf) and the minimum rainfall availability was found using five phylogenetically independent species pairs in wet and dry evergreen tree species, suggesting that rainfall is an important selective agent in the evolution of leaf hydraulic vulnerability. Greater within-site variability in P50(leaf) was found among dominant montane rainforest species in Tasmania than in Peru and this result is discussed within the context of differences in spatial and temporal environmental heterogeneity and parochial historical ecology.

  13. Harnessing Genetic Variation in Leaf Angle to Increase Productivity of Sorghum bicolor.

    Science.gov (United States)

    Truong, Sandra K; McCormick, Ryan F; Rooney, William L; Mullet, John E

    2015-11-01

    The efficiency with which a plant intercepts solar radiation is determined primarily by its architecture. Understanding the genetic regulation of plant architecture and how changes in architecture affect performance can be used to improve plant productivity. Leaf inclination angle, the angle at which a leaf emerges with respect to the stem, is a feature of plant architecture that influences how a plant canopy intercepts solar radiation. Here we identify extensive genetic variation for leaf inclination angle in the crop plant Sorghum bicolor, a C4 grass species used for the production of grain, forage, and bioenergy. Multiple genetic loci that regulate leaf inclination angle were identified in recombinant inbred line populations of grain and bioenergy sorghum. Alleles of sorghum dwarf-3, a gene encoding a P-glycoprotein involved in polar auxin transport, are shown to change leaf inclination angle by up to 34° (0.59 rad). The impact of heritable variation in leaf inclination angle on light interception in sorghum canopies was assessed using functional-structural plant models and field experiments. Smaller leaf inclination angles caused solar radiation to penetrate deeper into the canopy, and the resulting redistribution of light is predicted to increase the biomass yield potential of bioenergy sorghum by at least 3%. These results show that sorghum leaf angle is a heritable trait regulated by multiple loci and that genetic variation in leaf angle can be used to modify plant architecture to improve sorghum crop performance.

  14. Plant trait variation along an altitudinal gradient in mediterranean high mountain grasslands: controlling the species turnover effect.

    Science.gov (United States)

    Pescador, David S; de Bello, Francesco; Valladares, Fernando; Escudero, Adrián

    2015-01-01

    Assessing changes in plant functional traits along gradients is useful for understanding the assembly of communities and their response to global and local environmental drivers. However, these changes may reflect the effects of species composition (i.e. composition turnover), species abundance (i.e. species interaction), and intra-specific trait variability (i.e. species plasticity). In order to determine the relevance of the latter, trait variation can be assessed under minimal effects of composition turnover. Nine sampling sites were established along an altitudinal gradient in a Mediterranean high mountain grassland community with low composition turnover (Madrid, Spain; 1940 m-2419 m). Nine functional traits were also measured for ten individuals of around ten plant species at each site, for a total of eleven species across all sites. The relative importance of different sources of variability (within/between site and intra-/inter-specific functional diversity) and trait variation at species and community level along the considered gradients were explored. We found a weak individual species response to altitude and other environmental variables although in some cases, individuals were smaller and leaves were thicker at higher elevations. This lack of species response was most likely due to greater within- than between-site species variation. At the community level, inter-specific functional diversity was generally greater than the intra-specific component except for traits linked to leaf element content (leaf carbon content, leaf nitrogen content, δ13C and δ15N). Inter-specific functional diversity decreased with lower altitude for four leaf traits (specific leaf area, leaf dry matter content, δ13C and δ15N), suggesting trait convergence between species at lower elevations, where water shortage may have a stronger environmental filtering effect than colder temperatures at higher altitudes. Our results suggest that, within a vegetation type encompassing

  15. Relationships between nutrient-related plant traits and combinations of soil N and P fertility measures.

    Directory of Open Access Journals (Sweden)

    Yuki Fujita

    Full Text Available Soil fertility and nutrient-related plant functional traits are in general only moderately related, hindering the progress in trait-based prediction models of vegetation patterns. Although the relationships may have been obscured by suboptimal choices in how soil fertility is expressed, there has never been a systematic investigation into the suitability of fertility measures. This study, therefore, examined the effect of different soil fertility measures on the strength of fertility-trait relationships in 134 natural plant communities. In particular, for eight plot-mean traits we examined (1 whether different elements (N or P have contrasting or shared influences, (2 which timescale of fertility measures (e.g. mineralization rates for one or five years has better predictive power, and (3 if integrated fertility measures explain trait variation better than individual fertility measures. Soil N and P had large mutual effects on leaf nutrient concentrations, whereas they had element-specific effects on traits related to species composition (e.g. Grime's CSR strategy. The timescale of fertility measures only had a minor impact on fertility-trait relationships. Two integrated fertility measures (one reflecting overall fertility, another relative availability of soil N and P were related significantly to most plant traits, but were not better in explaining trait variation than individual fertility measures. Using all fertility measures together, between-site variations of plant traits were explained only moderately for some traits (e.g. 33% for leaf N concentrations but largely for others (e.g. 66% for whole-canopy P concentration. The moderate relationships were probably due to complex regulation mechanisms of fertility on traits, rather than to a wrong choice of fertility measures. We identified both mutual (i.e. shared and divergent (i.e. element-specific and stoichiometric effects of soil N and P on traits, implying the importance of explicitly

  16. Relationships between nutrient-related plant traits and combinations of soil N and P fertility measures.

    Science.gov (United States)

    Fujita, Yuki; van Bodegom, Peter M; Witte, Jan-Philip M

    2013-01-01

    Soil fertility and nutrient-related plant functional traits are in general only moderately related, hindering the progress in trait-based prediction models of vegetation patterns. Although the relationships may have been obscured by suboptimal choices in how soil fertility is expressed, there has never been a systematic investigation into the suitability of fertility measures. This study, therefore, examined the effect of different soil fertility measures on the strength of fertility-trait relationships in 134 natural plant communities. In particular, for eight plot-mean traits we examined (1) whether different elements (N or P) have contrasting or shared influences, (2) which timescale of fertility measures (e.g. mineralization rates for one or five years) has better predictive power, and (3) if integrated fertility measures explain trait variation better than individual fertility measures. Soil N and P had large mutual effects on leaf nutrient concentrations, whereas they had element-specific effects on traits related to species composition (e.g. Grime's CSR strategy). The timescale of fertility measures only had a minor impact on fertility-trait relationships. Two integrated fertility measures (one reflecting overall fertility, another relative availability of soil N and P) were related significantly to most plant traits, but were not better in explaining trait variation than individual fertility measures. Using all fertility measures together, between-site variations of plant traits were explained only moderately for some traits (e.g. 33% for leaf N concentrations) but largely for others (e.g. 66% for whole-canopy P concentration). The moderate relationships were probably due to complex regulation mechanisms of fertility on traits, rather than to a wrong choice of fertility measures. We identified both mutual (i.e. shared) and divergent (i.e. element-specific and stoichiometric) effects of soil N and P on traits, implying the importance of explicitly

  17. Leaf anatomy and photosynthesis

    OpenAIRE

    Berghuijs, H.N.C.

    2016-01-01

    Keywords: CO2 diffusion, C3 photosynthesis, mesophyll conductance, mesophyll resistance, re-assimilation, photorespiration, respiration, tomato Herman Nicolaas Cornelis Berghuijs (2016). Leaf anatomy and photosynthesis; unravelling the CO2 diffusion pathway in C3 leaves. PhD thesis. Wageningen University, Wageningen, The Netherlands, with summaries in English and Dutch. 286 pages Optimizing photosynthesis can contribute to improving crop yield, which is necessary to meet the increasing global...

  18. Allozyme gene diversities in some leaf beetles (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Krafsur, E S

    1999-08-01

    Gene diversity at allozyme loci was investigated in the bean leaf beetle, Ceratoma trifurcata Forster; the elm leaf beetle, Xanthogaleruca luteola (Muller); the cottonwood leaf beetle, Chrysomela scripta Fabricus; the western corn rootworm, Diabrotica virgifera virgifera LeConte; the southern corn rootworm, also called the spotted cucumber beetle, D. undecimpunctata howardi Baker; the northern corn rootworm, D. barberi Smith and Lawrence; and the Colorado potato beetle, Leptinotarsa decemlineata (Say). Six of these species are economically important pests of crops and display adaptive traits that may correlate with genetic diversity. Gene diversity H(E) in bean leaf beetles was 17.7 +/- 4.0% among 32 loci. In western corn rootworms, H(E) = 4.8 +/- 2.0% among 36 loci, and in spotted cucumber beetles, H(E) = 11.9 +/- 2.7% among 39 loci. Diversity among 27 loci was 10.5 +/- 4.3% in the Colorado potato beetle. The data were compared with gene diversity estimates from other leaf beetle species in which heterozygosities varied from 0.3 to 21% and no correlation was detected among heterozygosities, geographic ranges, or population densities. Distributions of single-locus heterozygosities were consistent with selective neutrality of alleles.

  19. Photosynthesis in developing leaf of juveniles and adults of three Mediterranean species with different growth forms.

    Science.gov (United States)

    Chondrogiannis, Christos; Grammatikopoulos, George

    2016-12-01

    Leaf development is influenced by almost all the prevailing environmental conditions as well as from the conditions at the time of bud formation. Furthermore, the growth form of a plant determines the leaf longevity and subsequently the investment in biomass and the internal structure of the mesophyll. Therefore, photosynthetic traits of a growing leaf, though, partly predetermined, should also acclimate to temporal changes during developmental period. In addition, the age of the plant can affect photosynthesis of the growing leaf, yet, in the majority of studies, the age is associated to the size of the plant. To test if the reproductive status of the plant affects the time kinetics of the photosynthetic capacity of a growing leaf and the relative contribution of the plants' growth form to the whole procedure, field measurements were conducted in juveniles (prereproductive individuals) and adults (fully reproductive individuals) of an evergreen sclerophyllous shrub (Nerium oleander), a semi-deciduous dimorphic shrub (Phlomis fruticosa), and a winter deciduous tree with pre-leafing flowering (Cercis siliquastrum). PSII structural and functional integrity was progressively developed in all species, but already completed, only some days after leaf expansion in P. fruticosa. Developing leaf as well as fully developed leaf in adults of C. siliquastrum showed enhanced relative size of the pool of final PSI electron acceptors. Photosynthetic traits between juveniles and adults of P. fruticosa were similar, though the matured leaf of adults exhibited lower transpiration rates and improved water-use efficiency than that of juveniles. Adults of the evergreen shrub attained higher CO2 assimilation rate than juveniles in matured leaf which can be attributed to higher electron flow devoted to carboxylation, and lower photorespiration rate. The reproductive phase of the plant seemed to be involved in modifications of the PSII and PSI functions of the deciduous tree, in

  20. Understanding soil erosion process within herbaceous vegetative hedges using plant functional traits approach in North-West Europe

    Science.gov (United States)

    Kervroëdan, Léa; Armand, Romain; Saunier, Mathieu; Faucon, Michel-Pierre

    2017-04-01

    Runoff and soil erosion induce major environmental and economic damages. Concentrated runoff control by aboveground plant biomass in upstream areas constitutes a key feature to reduce runoff and soil erosion in Western Europe (WE). Indeed, aboveground plant biomass can reduce runoff and soil erosion respectively by increasing hydraulic roughness and trapping sediments. However, studies of plant effect on runoff reduction are usually based on the taxonomical characterisation of species and do not refer to effect of aboveground plant functional traits. Plant functional traits approach allows to understand ecosystem processes and quantify services. Traits effect could vary depending on hydrological processes (i.e., discharge) and their aggregation could have a synergetic effect on hydraulic roughness and erosion reduction. In this study, objectives are to i) examine effects of aboveground plant functional traits of herbaceous hedges on hydraulic roughness; ii) test the effects of their aggregation on hydraulic roughness. Seven aboveground functional traits were measured on 14 indigenous plant species from North-West Europe with a high morphological variability (stem and leaf densities; stem diameter, stiffness and dry matter content; leaf area and specific leaf area (SLA)). Those species are perennial herbaceous caespitose or comprising dry biomass in winter. Effects of plant functional traits and their abundance within the community on hydraulic roughness were examined using a runoff simulator at four discharges. Furthermore, the effect of plant functional diversity was analysed using four monospecific (mono-trait) conditions compared to multispecific (multi-traits) conditions. Results showed traits and their abundance influence hydraulic roughness. Indeed, leaf density and leaf area (traits), as well as plant community weighted stem, leaf and shoot areas, stem diameter and SLA are significantly correlated to hydraulic roughness. Moreover, leaf density and leaf area

  1. 丝栗栲、苦槠和青冈幼苗叶片功能性状对增温和施氮的响应1)%Responses of Leaf Functional Traits of Castanopis s fargesii, Castanpo sis sclerophylla an d Cyclobalanopsis glauca Seedlings to Warming and Nitrogen Addition under Artificial Control Conditions

    Institute of Scientific and Technical Information of China (English)

    王致远; 赵广东; 王兵; 邓宗富; 夏晨; 罗嘉东; 王财英

    2014-01-01

    warming , nitrogen fertilizer and their interaction on specific leaf area , leaf nitrogen content per unit mass , leaf nitrogen content per unit area and leaf dry matter content of Castanopsis fargesii, Castanopsis sclerophylla and Cyclobalanopsis glauca seedings, the dominant species of evergreen broad-leaved forest in the mid-subtropical zone.From January 2012 to January 2013, the mean air temperature, the mean soil temperature at 5 cm and 20 cm depths were enhanced by 1.22℃, 1.05℃and 0.65℃.However, the mean air relative humidity, the mean soil volume water content at 5 cm and 20 cm depths were 7.07%, 7.02%and 5.52%lower than that in the control area , respectively .In the condition of warming , the leaf dry matter content was higher than that of the control area, while the specific leaf area and leaf nitrogen content per unit mass were opposite .The nitrogen addition led to the in-crease of leaf nitrogen content per unit mass , leaf nitrogen content per unit area and leaf dry matter content and the de-crease of specific leaf area .The specific leaf area , leaf nitrogen content per unit mass , leaf nitrogen content per unit area and leaf dry matter content responses of Castanopsis fargesii, Castanopsis sclerophylla and Cyclobalanopsis glauca to war-ming and nitrogen interaction were different .The independent effect of warming and nitrogen on the specific leaf area of Castanopsis fargesii was lower than that of their interactions , and the interactions on the specific leaf area of Castanopsis sclerophylla were similar to the independent nitrogen, but there was no significant effect on the specific leaf area of Castan-opsis fargesii.The response of three seedlings leaf nitrogen content per unit mass to warming and nitrogen was basically con -sistent irrespective of the effects of their independent and interactive .The independent and interactive effects of warming and nitrogen to the leaf nitrogen content per unit area of Castanopsis sclerophylla were similar

  2. Leaf hydraulic conductance for a tank bromeliad: axial and radial pathways for moving and conserving water.

    Science.gov (United States)

    North, Gretchen B; Lynch, Frank H; Maharaj, Franklin D R; Phillips, Carly A; Woodside, Walter T

    2013-01-01

    Epiphytic plants in the Bromeliaceae known as tank bromeliads essentially lack stems and absorptive roots and instead take up water from reservoirs formed by their overlapping leaf bases. For such plants, leaf hydraulic conductance is plant hydraulic conductance. Their simple strap-shaped leaves and parallel venation make them suitable for modeling leaf hydraulic conductance based on vasculature and other anatomical and morphological traits. Plants of the tank bromeliad Guzmania lingulata were investigated in a lowland tropical forest in Costa Rica and a shaded glasshouse in Los Angeles, CA, USA. Stomatal conductance to water vapor and leaf anatomical variables related to hydraulic conductance were measured for both groups. Tracheid diameters and numbers of vascular bundles (veins) were used with the Hagen-Poiseuille equation to calculate axial hydraulic conductance. Measurements of leaf hydraulic conductance using the evaporative flux method were also made for glasshouse plants. Values for axial conductance and leaf hydraulic conductance were used in a model based on leaky cable theory to estimate the conductance of the radial pathway from the vein to the leaf surface and to assess the relative contributions of both axial and radial pathways. In keeping with low stomatal conductance, low stomatal density, low vein density, and narrow tracheid diameters, leaf hydraulic conductance for G. lingulata was quite low in comparison with most other angiosperms. Using the predicted axial conductance in the leaky cable model, the radial resistance across the leaf mesophyll was predicted to predominate; lower, more realistic values of axial conductance resulted in predicted radial resistances that were closer to axial resistance in their impact on total leaf resistance. Tracer dyes suggested that water uptake through the tank region of the leaf was not limiting. Both dye movement and the leaky cable model indicated that the leaf blade of G. lingulata was structurally and

  3. OSCILLATOR: A system for analysis of diurnal leaf growth using infrared photography combined with wavelet transformation

    Directory of Open Access Journals (Sweden)

    Bours Ralph

    2012-08-01

    Full Text Available Abstract Background Quantification of leaf movement is an important tool for characterising the effects of environmental signals and the circadian clock on plant development. Analysis of leaf movement is currently restricted by the attachment of sensors to the plant or dependent upon visible light for time-lapse photography. The study of leaf growth movement rhythms in mature plants under biological relevant conditions, e.g. diurnal light and dark conditions, is therefore problematic. Results Here we present OSCILLATOR, an affordable system for the analysis of rhythmic leaf growth movement in mature plants. The system contains three modules: (1 Infrared time-lapse imaging of growing mature plants (2 measurement of projected distances between leaf tip and plant apex (leaf tip tracking growth-curves and (3 extraction of phase, period and amplitude of leaf growth oscillations using wavelet analysis. A proof-of-principle is provided by characterising parameters of rhythmic leaf growth movement of different Arabidopsis thaliana accessions as well as of Petunia hybrida and Solanum lycopersicum plants under diurnal conditions. The amplitude of leaf oscillations correlated to published data on leaf angles, while amplitude and leaf length did not correlate, suggesting a distinct leaf growth profile for each accession. Arabidopsis mutant accession Landsberg erecta displayed a late phase (timing of peak oscillation compared to other accessions and this trait appears unrelated to the ERECTA locus. Conclusions OSCILLATOR is a low cost and easy to implement system that can accurately and reproducibly quantify rhythmic growth of mature plants for different species under diurnal light/dark cycling.

  4. Plastic traits of an exotic grass contribute to its abundance but are not always favourable.

    Directory of Open Access Journals (Sweden)

    Jennifer Firn

    Full Text Available In herbaceous ecosystems worldwide, biodiversity has been negatively impacted by changed grazing regimes and nutrient enrichment. Altered disturbance regimes are thought to favour invasive species that have a high phenotypic plasticity, although most studies measure plasticity under controlled conditions in the greenhouse and then assume plasticity is an advantage in the field. Here, we compare trait plasticity between three co-occurring, C(4 perennial grass species, an invader Eragrostis curvula, and natives Eragrostis sororia and Aristida personata to grazing and fertilizer in a three-year field trial. We measured abundances and several leaf traits known to correlate with strategies used by plants to fix carbon and acquire resources, i.e. specific leaf area (SLA, leaf dry matter content (LDMC, leaf nutrient concentrations (N, C:N, P, assimilation rates (Amax and photosynthetic nitrogen use efficiency (PNUE. In the control treatment (grazed only, trait values for SLA, leaf C:N ratios, Amax and PNUE differed significantly between the three grass species. When trait values were compared across treatments, E. curvula showed higher trait plasticity than the native grasses, and this correlated with an increase in abundance across all but the grazed/fertilized treatment. The native grasses showed little trait plasticity in response to the treatments. Aristida personata decreased significantly in the treatments where E. curvula increased, and E. sororia abundance increased possibly due to increased rainfall and not in response to treatments or invader abundance. Overall, we found that plasticity did not favour an increase in abundance of E. curvula under the grazed/fertilized treatment likely because leaf nutrient contents increased and subsequently its' palatability to consumers. E. curvula also displayed a higher resource use efficiency than the native grasses. These findings suggest resource conditions and disturbance regimes can be manipulated to

  5. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits.

    Science.gov (United States)

    Biazzi, Elisa; Nazzicari, Nelson; Pecetti, Luciano; Brummer, E Charles; Palmonari, Alberto; Tava, Aldo; Annicchiarico, Paolo

    2017-01-01

    Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3-0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits

  6. A potential role of flag leaf potassium in conferring tolerance to drought-induced leaf senescence in barley

    Directory of Open Access Journals (Sweden)

    Seyed A. Hosseini

    2016-02-01

    Full Text Available Terminal drought stress decreases crop yields by inducing abscisic acid (ABA and premature leaf senescence. As potassium (K is known to interfere with ABA homeostasis we addressed the question whether there is genetic variability regarding the role of K nutrition in ABA homeostasis and drought tolerance. To compare their response to drought stress, two barley lines contrasting in drought-induced leaf senescence were grown in a pot experiment under high and low K supply for the analysis of flag leaves from the same developmental stage. Relative to the drought-sensitive line LPR, the line HPR retained more K in its flag leaves under low K supply and showed delayed flag leaf senescence under terminal drought stress. High K retention was further associated with a higher leaf water status, a higher concentration of starch and other primary carbon metabolites. With regard to ABA homeostasis, HPR accumulated less ABA but higher levels of the ABA degradation products phaseic acid and dehydro-phaseic acid. Under K deficiency this went along with higher transcript levels of ABA8’-HYDROXYLASE, encoding a key enzyme in ABA degradation. The present study provides evidence for a positive impact of the K nutritional status on ABA homeostasis and carbohydrate metabolism under drought stress. We conclude that genotypes with a high K nutritional status in the flag leaf show superior drought tolerance by promoting ABA degradation but attenuating starch degradation which delays flag leaf senescence. Flag leaf K levels may thus represent a useful trait for the selection of drought-tolerant barley cultivars.

  7. Sickle Cell Trait

    Science.gov (United States)

    ... Websites About Us Information For… Media Policy Makers Sickle Cell Trait Language: English (US) Español (Spanish) Recommend on Facebook Tweet Share Compartir Get Screened for Sickle Cell Trait Did you know there’s more than one way ...

  8. Correlations between insect resistance and horticultural traits in potatoes

    Directory of Open Access Journals (Sweden)

    Velci Queiroz de Souza

    2006-01-01

    Full Text Available The objective of this study was to determine relationships between insect resistance and some horticulturaltraits and the implications on selection. A potato population of 11 clonal families derived from crosses between insect resistantand genotypes adapted to the southern region of Brazil was used. The following traits were evaluated: plant size and vigor,incidence of insect attacks on leaves and tubers, tuber yield and appearance components. Phenotypic and genotypic correlationsbetween leaf and tuber resistance were not significant for the population, while phenotypic correlations between the tworesistance types were significant for individual families, with exception of the family originated from the cross involving‘ND263-32’. The incidence of insect attacks on tubers was significantly correlated with tuber yield and appearance in familiesderived from crosses of ‘NYL235-4’. The manifold correlations of leaf resistance with horticultural traits for all families weresignificant and unfavorable.

  9. The reciprocal relationship between competition and intraspecific trait variation

    DEFF Research Database (Denmark)

    A Bennett, Jonathan; Riibak, Kersti; Tamme, Riin

    2016-01-01

    to both intra- and interspecific competition, frequently affecting competitive hierarchies. Intraspecific competition was lower for species that limited competition-induced increases in root allocation and had less variability in this trait overall. Interspecific competition was lower for species...... with larger leaves and lower specific leaf area than their neighbours. Switching to more stress tolerant strategies by increasing root diameter and leaf tissue density also reduced competition. However, dissimilarity in root tissue density also minimized competition, consistent with limiting similarity......1.Trait differences among plants are expected to influence the outcome of competition; competition should be strongest between similar species (or individuals) under limiting similarity, and between dissimilar species within competitive hierarchies. These hypotheses are often used to infer...

  10. Effects of Water Volume and Nitrogen Fertilization on Yield and Quality Traits of Air-cured Burley Tobacco (Nicotianatabacum L.

    Directory of Open Access Journals (Sweden)

    Ascione S

    2014-12-01

    Full Text Available Based on a two-year field trial in the region of Campania (Southern Italy the effects of water volume and nitrogen fertilization on the yield and quality of Burley tobacco (Nicotianatabacum L. were investigated with reference to the following traits: cured leaf yield, price index, yield value, leaf area, specific leaf weight, burning capacity, color parameters, total alkaloid, nitrate and chloride leaf content. The experimental design was a factorial comparison among three water volumes (40, 80 and 120% evapotranspiration (ET, four nitrogen fertilization levels (0, 80, 160 and 240 kg ha-1 and two genotypes (cv TN86 and the hybrid R7-11. The yield of cured leaves rose with the increase in water and nitrogen availability, albeit at a decreasing rate. With the increase in water volume, the price index, burning capacity, specific leaf weight, total alkaloid and nitrate content decreased, while leaf area and chloride content increased. Up to a rate of 160 kg ha-1, nitrogen fertilization increased the price index, yield value, burning capacity, leaf area, specific leaf weight, total alkaloid and nitrates, and reduced leaf chloride content especially at 40% ET water volume. Both, nitrogen fertilization and water volume had little influence on leaf color. The year had considerable effects on yield, leaf area and color parameters, with higher values in the rainier season. In the two years, genotype TN86 showed higher stability for yield and yield value, lower alkaloid and higher nitrate content in the leaf than the R7-11 hybrid.

  11. Zellweger Spectrum

    Science.gov (United States)

    ... severe defect, resulting in essentially nonfunctional peroxisomes. This phenomenon produces the range of severity of the disorders. How is the Zellweger Spectrum Diagnosed? The distinctive shape of the head and face of a child born with one of the diseases of the ...

  12. Comparing Leaf and Root Insertion

    Directory of Open Access Journals (Sweden)

    Jaco Geldenhuys

    2010-07-01

    Full Text Available We consider two ways of inserting a key into a binary search tree: leaf insertion which is the standard method, and root insertion which involves additional rotations. Although the respective cost of constructing leaf and root insertion binary search trees trees, in terms of comparisons, are the same in the average case, we show that in the worst case the construction of a root insertion binary search tree needs approximately 50% of the number of comparisons required by leaf insertion.

  13. Antimicrobial activity of commercial Olea europaea (olive) leaf extract.

    Science.gov (United States)

    Sudjana, Aurelia N; D'Orazio, Carla; Ryan, Vanessa; Rasool, Nooshin; Ng, Justin; Islam, Nabilah; Riley, Thomas V; Hammer, Katherine A

    2009-05-01

    The aim of this research was to investigate the activity of a commercial extract derived from the leaves of Olea europaea (olive) against a wide range of microorganisms (n=122). Using agar dilution and broth microdilution techniques, olive leaf extract was found to be most active against Campylobacter jejuni, Helicobacter pylori and Staphylococcus aureus [including meticillin-resistant S. aureus (MRSA)], with minimum inhibitory concentrations (MICs) as low as 0.31-0.78% (v/v). In contrast, the extract showed little activity against all other test organisms (n=79), with MICs for most ranging from 6.25% to 50% (v/v). In conclusion, olive leaf extract was not broad-spectrum in action, showing appreciable activity only against H. pylori, C. jejuni, S. aureus and MRSA. Given this specific activity, olive leaf extract may have a role in regulating the composition of the gastric flora by selectively reducing levels of H. pylori and C. jejuni.

  14. Comparative leaf development in angiosperms.

    Science.gov (United States)

    Tsukaya, Hirokazu

    2014-02-01

    Recent accumulation of our knowledge on basic leaf development mechanisms in model angiosperm species has allowed us to pursue evolutionary development (evo/devo) studies of various kinds of leaf development. As a result, unexpected findings and clues have been unearthed aiding our understanding of the mechanisms involved in the diversity of leaf morphology, although the covered remain limited. In this review, we highlight recent findings of diversified leaf development in angiosperms. Copyright © 2013 The Author. Published by Elsevier Ltd.. All rights reserved.

  15. Increasing leaf vein density by mutagenesis: laying the foundations for C4 rice.

    Directory of Open Access Journals (Sweden)

    Aryo B Feldman

    Full Text Available A high leaf vein density is both an essential feature of C4 photosynthesis and a foundation trait to C4 evolution, ensuring the optimal proportion and proximity of mesophyll and bundle sheath cells for permitting the rapid exchange of photosynthates. Two rice mutant populations, a deletion mutant library with a cv. IR64 background (12,470 lines and a T-DNA insertion mutant library with a cv. Tainung 67 background (10,830 lines, were screened for increases in vein density. A high throughput method with handheld microscopes was developed and its accuracy was supported by more rigorous microscopy analysis. Eight lines with significantly increased leaf vein densities were identified to be used as genetic stock for the global C4 Rice Consortium. The candidate population was shown to include both shared and independent mutations and so more than one gene controlled the high vein density phenotype. The high vein density trait was found to be linked to a narrow leaf width trait but the linkage was incomplete. The more genetically robust narrow leaf width trait was proposed to be used as a reliable phenotypic marker for finding high vein density variants in rice in future screens.

  16. Leaf gas films, underwater photosynthesis and plant species distributions in a flood gradient

    NARCIS (Netherlands)

    Winkel, Anders; Visser, Eric J W; Colmer, Timothy D.; Brodersen, Klaus P.; Voesenek, Laurentius A C J; Sand-Jensen, Kaj; Pedersen, Ole

    2016-01-01

    Traits for survival during flooding of terrestrial plants include stimulation or inhibition of shoot elongation, aerenchyma formation and efficient gas exchange. Leaf gas films form on superhydrophobic cuticles during submergence and enhance underwater gas exchange. The main hypothesis tested was th

  17. The altitudinal patterns of leaf C∶N∶P stoichiometry are regulated by plant growth form, climate and soil on Changbai Mountain, China.

    Science.gov (United States)

    Zhao, Ning; He, Nianpeng; Wang, Qiufeng; Zhang, Xinyu; Wang, Ruili; Xu, Zhiwei; Yu, Guirui

    2014-01-01

    Understanding the geographic patterns and potential drivers of leaf stoichiometry is critical for modelling the nutrient fluxes of ecosystems and to predict the responses of ecosystems to global changes. This study aimed to explore the altitudinal patterns and potential drivers of leaf C∶N∶P stoichiometry. We measured the concentrations of leaf C, N and P in 175 plant species as well as soil nutrient concentrations along an altitudinal transect (500-2300 m) on the northern slope of Changbai Mountain, China to explore the response of leaf C∶N∶P stoichiometry to plant growth form (PGF), climate and soil. Leaf C, N, P and C∶N∶P ratios showed significant altitudinal trends. In general, leaf C and C∶N∶P ratios increased while leaf N and P decreased with elevation. Woody and herbaceous species showed different responses to altitudinal gradients. Trees had the largest variation in leaf C, C∶N and C∶P ratios, while herbs showed the largest variation in leaf N, P and N∶P ratio. PGF, climate and soil jointly regulated leaf stoichiometry, explaining 17.6% to 52.1% of the variation in the six leaf stoichiometric traits. PGF was more important in explaining leaf stoichiometry variation than soil and climate. Our findings will help to elucidate the altitudinal patterns of leaf stoichiometry and to model ecosystem nutrient cycling.

  18. 7 CFR 29.2528 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.2528 Section 29.2528 Agriculture Regulations...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2528 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  19. 7 CFR 29.3033 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  20. 7 CFR 29.3525 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  1. Leaf growth of contrasting Poa species

    NARCIS (Netherlands)

    Fiorani, Fabio

    2002-01-01

    In the grass genus Poa a wide variation in final leaf size and leaf growth rate exists. In this thesis leaf growth was analyzed at different levels. At the cellular level, inherent variation in leaf elongation rate and final leaf size was correlated to the length of the elongation zone and to merist

  2. 7 CFR 29.1028 - Leaf.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.1028 Section 29.1028 Agriculture Regulations... Type 92) § 29.1028 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf....

  3. Aridity induces super-optimal investment in leaf venation by Eucalyptus and Corymbia

    Science.gov (United States)

    Drake, Paul L.; de Boer, Hugo J.; Price, Charles A.; Veneklaas, Erik J.

    2016-04-01

    The close relationship between leaf water status and stomatal conductance implies that the hydraulic architecture of leaves poses an important constraint on carbon uptake, specifically in arid environments with high evaporative demands. However, it remains uncertain how morphological, hydraulic and photosynthetic traits are coordinated to achieve optimal leaf functioning in arid environments. Zwieniecki and Boyce (2014) proposed a generic framework on the hydraulic architecture of leaves based on the argument that water is optimally distributed when the lateral distance between neighboring water transport veins (dx) is approximately equal to the distance from these veins to the epidermis (dy), expressed as dx:dy ≈1. Many derived angiosperms realize this optimal hydraulic architecture by closely coordinating leaf vein density with leaf thickness and the lateral position of veins inside the leaf. Zwieniecki and Boyce (2014) further suggested that over-investment in veins (dx:dy photosynthetic traits of 65 species (401 individuals) within the widely distributed and closely related genera Eucalyptus and Corymbia along a 2000-km-long aridity gradient in Western Australia (see Schulze et al., 2006). We inferred the potential functional benefit of reducing dx beyond dy using a semi-empirical model that links leaf morphology and hydraulics to photosynthesis. Our results reveal that Eucalyptus and Corymbia evolved extremely high vein densities in addition to thick amphistomatous leaf morphologies along the natural aridity gradient resulting in dx:dy ratios ranging between 0.8 and 0.08. We propose that as the thickness of amphistomatous leaves increases, the effect of reducing dx beyond dy is to offset the reduction in photosynthesis that would result from the theoretical optimal architecture of dx:dy ≈1. Our model quantified the resulting relative gain in photosynthesis at 10% to 15%, which could provide a crucial gas exchange advantage. We conclude that aridity

  4. Genetic diversity of upland rice germplasm in Malaysia based on quantitative traits.

    Science.gov (United States)

    Sohrabi, M; Rafii, M Y; Hanafi, M M; Siti Nor Akmar, A; Latif, M A

    2012-01-01

    Genetic diversity is prerequisite for any crop improvement program as it helps in the development of superior recombinants. Fifty Malaysian upland rice accessions were evaluated for 12 growth traits, yield and yield components. All of the traits were significant and highly significant among the accessions. The higher magnitudes of genotypic and phenotypic coefficients of variation were recorded for flag leaf length-to-width ratio, spikelet fertility, and days to flowering. High heritability along with high genetic advance was registered for yield of plant, days to flowering, and flag leaf length-to-width ratio suggesting preponderance of additive gene action in the gene expression of these characters. Plant height showed highly significant positive correlation with most of the traits. According to UPGMA cluster analysis all accessions were clustered into six groups. Twelve morphological traits provided around 77% of total variation among the accessions.

  5. Genetic Diversity of Upland Rice Germplasm in Malaysia Based on Quantitative Traits

    Directory of Open Access Journals (Sweden)

    M. Sohrabi

    2012-01-01

    Full Text Available Genetic diversity is prerequisite for any crop improvement program as it helps in the development of superior recombinants. Fifty Malaysian upland rice accessions were evaluated for 12 growth traits, yield and yield components. All of the traits were significant and highly significant among the accessions. The higher magnitudes of genotypic and phenotypic coefficients of variation were recorded for flag leaf length-to-width ratio, spikelet fertility, and days to flowering. High heritability along with high genetic advance was registered for yield of plant, days to flowering, and flag leaf length-to-width ratio suggesting preponderance of additive gene action in the gene expression of these characters. Plant height showed highly significant positive correlation with most of the traits. According to UPGMA cluster analysis all accessions were clustered into six groups. Twelve morphological traits provided around 77% of total variation among the accessions.

  6. Quantifying multi-dimensional functional trait spaces of trees: empirical versus theoretical approaches

    Science.gov (United States)

    Ogle, K.; Fell, M.; Barber, J. J.

    2016-12-01

    Empirical, field studies of plant functional traits have revealed important trade-offs among pairs or triplets of traits, such as the leaf (LES) and wood (WES) economics spectra. Trade-offs include correlations between leaf longevity (LL) vs specific leaf area (SLA), LL vs mass-specific leaf respiration rate (RmL), SLA vs RmL, and resistance to breakage vs wood density. Ordination analyses (e.g., PCA) show groupings of traits that tend to align with different life-history strategies or taxonomic groups. It is unclear, however, what underlies such trade-offs and emergent spectra. Do they arise from inherent physiological constraints on growth, or are they more reflective of environmental filtering? The relative importance of these mechanisms has implications for predicting biogeochemical cycling, which is influenced by trait distributions of the plant community. We address this question using an individual-based model of tree growth (ACGCA) to quantify the theoretical trait space of trees that emerges from physiological constraints. ACGCA's inputs include 32 physiological, anatomical, and allometric traits, many of which are related to the LES and WES. We fit ACGCA to 1.6 million USFS FIA observations of tree diameters and heights to obtain vectors of trait values that produce realistic growth, and we explored the structure of this trait space. No notable correlations emerged among the 496 trait pairs, but stepwise regressions revealed complicated multi-variate structure: e.g., relationships between pairs of traits (e.g., RmL and SLA) are governed by other traits (e.g., LL, radiation-use efficiency [RUE]). We also simulated growth under various canopy gap scenarios that impose varying degrees of environmental filtering to explore the multi-dimensional trait space (hypervolume) of trees that died vs survived. The centroid and volume of the hypervolumes differed among dead and live trees, especially under gap conditions leading to low mortality. Traits most predictive

  7. The Role of Seagrass Traits in Mediating Zostera noltei Vulnerability to Mesograzers.

    Science.gov (United States)

    Martínez-Crego, Begoña; Arteaga, Pedro; Tomas, Fiona; Santos, Rui

    2016-01-01

    Understanding how intra-specific differences in plant traits mediate vulnerability to herbivores of relevant habitat-forming plants is vital to attain a better knowledge on the drivers of the structure and functioning of ecosystems. Such studies, however, are rare in seagrass-mesograzer systems despite the increasingly recognized relevance of mesograzers as seagrass consumers. We investigated the role and potential trade-offs of multiple leaf traits in mediating the vulnerability of the seagrass Zostera noltei to different mesograzer species, the amphipod Gammarus insensibilis and the isopod Idotea chelipes. We worked with plants from two different meadows for which contrasting chemical and structural traits were expected based on previous information. We found that plants with high vulnerability to mesograzers (i.e. those preferred and subjected to higher rates of leaf area loss) had not only higher nitrogen content and lower C:N, fibre, and phenolics, but also tender and thinner leaves. No trade-offs between chemical and structural traits of the seagrass were detected, as they were positively correlated. When leaf physical structure was removed using agar-reconstituted food, amphipod preference towards high-susceptibility plants disappeared; thus indicating that structural rather than chemical traits mediated the feeding preference. Removal of plant structure reduced the size of isopod preference to less than half, indicating a stronger contribution of structural traits (> 50%) but combined with chemical/nutritional traits in mediating the preference. We then hypothesized that the high environmental nutrient levels recorded in the meadow exhibiting high susceptibility modulate the differences observed between meadows in seagrass traits. To test this hypothesis, we exposed low-vulnerability shoots to eutrophic nutrient levels in a 6-week enrichment experiment. Nutrient enrichment increased Z. noltei nitrogen content and lowered C:N, fibre, and phenolics, but had

  8. The Role of Seagrass Traits in Mediating Zostera noltei Vulnerability to Mesograzers.

    Directory of Open Access Journals (Sweden)

    Begoña Martínez-Crego

    Full Text Available Understanding how intra-specific differences in plant traits mediate vulnerability to herbivores of relevant habitat-forming plants is vital to attain a better knowledge on the drivers of the structure and functioning of ecosystems. Such studies, however, are rare in seagrass-mesograzer systems despite the increasingly recognized relevance of mesograzers as seagrass consumers. We investigated the role and potential trade-offs of multiple leaf traits in mediating the vulnerability of the seagrass Zostera noltei to different mesograzer species, the amphipod Gammarus insensibilis and the isopod Idotea chelipes. We worked with plants from two different meadows for which contrasting chemical and structural traits were expected based on previous information. We found that plants with high vulnerability to mesograzers (i.e. those preferred and subjected to higher rates of leaf area loss had not only higher nitrogen content and lower C:N, fibre, and phenolics, but also tender and thinner leaves. No trade-offs between chemical and structural traits of the seagrass were detected, as they were positively correlated. When leaf physical structure was removed using agar-reconstituted food, amphipod preference towards high-susceptibility plants disappeared; thus indicating that structural rather than chemical traits mediated the feeding preference. Removal of plant structure reduced the size of isopod preference to less than half, indicating a stronger contribution of structural traits (> 50% but combined with chemical/nutritional traits in mediating the preference. We then hypothesized that the high environmental nutrient levels recorded in the meadow exhibiting high susceptibility modulate the differences observed between meadows in seagrass traits. To test this hypothesis, we exposed low-vulnerability shoots to eutrophic nutrient levels in a 6-week enrichment experiment. Nutrient enrichment increased Z. noltei nitrogen content and lowered C:N, fibre, and

  9. Variability of leaf characteristics in different pedunculate oak genotypes (Ouercus robur L

    Directory of Open Access Journals (Sweden)

    Nikolić Nataša P.

    2006-01-01

    Full Text Available The objective of this study was to determine genotype influences on pedunculate oak's leaf traits: leaf area, specific leaf area (leaf area per unit of leaf mass, concentration of photosynthetic pigments, rates of photosynthesis and respiration, and nutrient concentrations (nitrogen phosphorus, potassium, calcium, and sodium. Leaf samples were taken from seventeen Q. robur genotypes originating from clonal seed orchard Banov Brod (Srem, Vojvodina, Serbia. Leaf area of the studied genotypes ranged from 248.4 to 628.8 cm2, SLA from 109.4 to 160.7 cm2 dry matter-1, rates of photosynthesis and respiration from 6.98 to 20.32 and from 6.73 to 14.65 µmol O2 m-2 s-1, respectively. The leaves of genotype 35 contained the highest concentration of photosynthetic pigments, while the lowest were recorded in genotype 29. The following pattern of nutrient concentrations was obtained for the studied genotypes: N>Ca>K>P>Na. Genotype variability of P K, Ca, and Na concentrations was more pronounced when compared with nitrogen. Estimated quantitative differences are the consequence of interaction of certain genotype and common environmental conditions for all trees. These results will provide information on intraspecific variation of the studied leaf characteristics.

  10. Differentially phased leaf growth and movements in Arabidopsis depend on coordinated circadian and light regulation.

    Science.gov (United States)

    Dornbusch, Tino; Michaud, Olivier; Xenarios, Ioannis; Fankhauser, Christian

    2014-10-01

    In contrast to vastly studied hypocotyl growth, little is known about diel regulation of leaf growth and its coordination with movements such as changes in leaf elevation angle (hyponasty). We developed a 3D live-leaf growth analysis system enabling simultaneous monitoring of growth and movements. Leaf growth is maximal several hours after dawn, requires light, and is regulated by daylength, suggesting coupling between growth and metabolism. We identify both blade and petiole positioning as important components of leaf movements in Arabidopsis thaliana and reveal a temporal delay between growth and movements. In hypocotyls, the combination of circadian expression of PHYTOCHROME INTERACTING FACTOR4 (PIF4) and PIF5 and their light-regulated protein stability drives rhythmic hypocotyl elongation with peak growth at dawn. We find that PIF4 and PIF5 are not essential to sustain rhythmic leaf growth but influence their amplitude. Furthermore, EARLY FLOWERING3, a member of the evening complex (EC), is required to maintain the correct phase between growth and movement. Our study shows that the mechanisms underlying rhythmic hypocotyl and leaf growth differ. Moreover, we reveal the temporal relationship between leaf elongation and movements and demonstrate the importance of the EC for the coordination of these phenotypic traits.

  11. Detection of quantitative trait loci for carcass composition traits in pigs

    Directory of Open Access Journals (Sweden)

    Renard Christine

    2002-11-01

    Full Text Available Abstract A quantitative trait locus (QTL analysis of carcass composition data from a three-generation experimental cross between Meishan (MS and Large White (LW pig breeds is presented. A total of 488 F2 males issued from six F1 boars and 23 F1 sows, the progeny of six LW boars and six MS sows, were slaughtered at approximately 80 kg live weight and were submitted to a standardised cutting of the carcass. Fifteen traits, i.e. dressing percentage, loin, ham, shoulder, belly, backfat, leaf fat, feet and head weights, two backfat thickness and one muscle depth measurements, ham + loin and back + leaf fat percentages and estimated carcass lean content were analysed. Animals were typed for a total of 137 markers covering the entire porcine genome. Analyses were performed using a line-cross (LC regression method where founder lines were assumed to be fixed for different QTL alleles and a half/full sib (HFS maximum likelihood method where allele substitution effects were estimated within each half-/full-sib family. Additional analyses were performed to search for multiple linked QTL and imprinting effects. Significant gene effects were evidenced for both leanness and fatness traits in the telomeric regions of SSC 1q and SSC 2p, on SSC 4, SSC 7 and SSC X. Additional significant QTL were identified for ham weight on SSC 5, for head weight on SSC 1 and SSC 7, for feet weight on SSC 7 and for dressing percentage on SSC X. LW alleles were associated with a higher lean content and a lower fat content of the carcass, except for the fatness trait on SSC 7. Suggestive evidence of linked QTL on SSC 7 and of imprinting effects on SSC 6, SSC 7, SSC 9 and SSC 17 were also obtained.

  12. (TECTONA GRANDIS LEAF POWDER

    Directory of Open Access Journals (Sweden)

    Yash Mishra

    2015-01-01

    Full Text Available In this study, the adsorption potential of Teak (Tectona grandis leaf powder (TLP toremove Methylene blue (MB and Malachite Green (MG dye molecules from aqueoussolution was investigated. Batch experiments were conducted to evaluate the influenceof operational parameters such as, pH (2−9, adsorbent dosage (1−7 g/L, contact time(15−150 minutes and initial dye concentration (20−120 mg/L at stirring speed of 150rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4%and 95.1% was achieved for MB and MG dye, respectively. The experimentalequilibrium data were analysed using Langmuir, Freundlich and Temkin isothermmodels and it was found that, it fitted well to the Freundlich isotherm model. Thesurface structure and morphology of the adsorbent was characterized using scanningelectron microscopy (SEM and the presence of functional groups and its interactionwith the dye molecules were analysed using Fourier transform infrared spectroscopy(FTIR. Based on the investigation, it has been demonstrated that the teak leaf powderhas good potential for effective adsorption of methylene blue and malachite green dye.

  13. The artificial leaf.

    Science.gov (United States)

    Nocera, Daniel G

    2012-05-15

    To convert the energy of sunlight into chemical energy, the leaf splits water via the photosynthetic process to produce molecular oxygen and hydrogen, which is in a form of separated protons and electrons. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into spatially separated electron-hole pairs. The holes of this wireless current are captured by the oxygen evolving complex (OEC) of photosystem II (PSII) to oxidize water to oxygen. The electrons and protons produced as a byproduct of the OEC reaction are captured by ferrodoxin of photosystem I. With the aid of ferrodoxin-NADP(+) reductase, they are used to produce hydrogen in the form of NADPH. For a synthetic material to realize the solar energy conversion function of the leaf, the light-absorbing material must capture a solar photon to generate a wireless current that is harnessed by catalysts, which drive the four electron/hole fuel-forming water-splitting reaction under benign conditions and under 1 sun (100 mW/cm(2)) illumination. This Account describes the construction of an artificial leaf comprising earth-abundant elements by interfacing a triple junction, amorphous silicon photovoltaic with hydrogen- and oxygen-evolving catalysts made from a ternary alloy (NiMoZn) and a cobalt-phosphate cluster (Co-OEC), respectively. The latter captures the structural and functional attributes of the PSII-OEC. Similar to the PSII-OEC, the Co-OEC self-assembles upon oxidation of an earth-abundant metal ion from 2+ to 3+, may operate in natural water at room temperature, and is self-healing. The Co-OEC also activates H(2)O by a proton-coupled electron transfer mechanism in which the Co-OEC is increased by four hole equivalents akin to the S-state pumping of the Kok cycle of PSII. X-ray absorption spectroscopy studies have established that the Co-OEC is a structural relative of Mn(3)CaO(4)-Mn cubane of the PSII-OEC, where Co replaces Mn and the cubane is extended in a

  14. Extending