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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

INFLUENCE OF BENZYLADENINE ON SHOOT FORCING AND TISSUE CULTURE OF JUGLANS NIGRA L. AND QUERCUS RUBRA L.

Holsinger, Andrew Craig 01 January 2008 (has links)
Shoot production and in vitro performance of Juglans nigra L and Quercus rubra L. was studied where 0, 3, 10, 30, or 100mM benzyladenine (BA) in a 20% white exterior latex paint diluted with deionized water were applied separately to 40 cm branch segments to determine the most effective concentration of benzyladenine on bud break and shoot growth. Softwood shoot production was maximized in the harvest months of March and April for J. nigra. Softwood shoot production was maximized in the harvest months of April and August for Q. rubra. Both shoot number and shoot length of softwood shoots decreased linearly with increasing BA concentrations applied to the branch segments of both species. Shoot production also decreased for both species during the dormant season September-December. The softwood shoots were surface disinfested and established on either 0 or 5µM Long Preece medium. When all BA treated softwood shoots were compared to the controls, the BA in the medium caused a significant increase in the number of shoots produced by explants obtained from the branch segments painted with BA. Painting with BA also increased shoot production in vitro, only if BA was also in the medium. Nodal explants cultured on 5µM LP medium taken from softwood shoots forced from branch segments painted with 3mM BA produced more shoots than any other BA concentration applied to branch segments except nodal explants on 5µM LP medium taken from softwood shoots forced from branch segments painted with 30mM BA.
2

Homeopatiškai paruošti preparatai iš Juglans nigra L. kevalo: biologiškai aktyvių junginių analizė ir antioksidacinio aktyvumo tyrimas / Homeopatically produced preparation from Juglans nigra L. shell: the analysis of biologically active compounds and the antioxidant activity study

Peleckytė, Urtė 01 July 2014 (has links)
Homeopatiniais vadinami preparatai, kurie yra pagaminti iš homeopatinių žaliavų, naudojant homeopatinės gamybos procedūras. Biologiniam homeopatinių preparatų aktyvumui tirti mokslininkai naudoja tuos pačius tyrimų metodus, kaip ir kitų rūšių cheminiams preparatams [32]. Šiam tyrimui pasirinkta homeopatinė juodojo riešuto (Juglans nigra L.) kevalo tinktūra ir jos D1 bei C1 praskiedimai – tai nedidelio laipsnio skiediniai, kuriuose veikliąsias medžiagas dar galima įdentifikuoti ir koncentracijas bei biologinį aktyvumą vertinti turimais tyrimo metodais. Mokslinės literatūros šaltiniuose skelbiama, jog juodojo riešuto kevale yra devynios pagrindinės cheminės medžiagos [29]. Nustatyta, jog riešuto viena iš pagrindinių veikliųjų medžagų yra juglonas, kuris turi citotoksinių savybių prieš melonomos, kepenų, plaučių, širdies, kraujo ląsteles [25,28,38,39]. Kadangi mokslinių tyrimų su preparatais, pagamintais iš juodojo riešuto, atlikta nedaug, todėl buvo pasirinkta ištirti polifenolinių junginių, juglono kiekį pagamintuose tirpaluose bei nustatyti jų antioksidacines savybes. Darbo tikslas: Homeopatiškai paruošti iš juodojo riešuto kevalo pradinę tinktūrą ir jos D1 bei C1 praskiedimus, ištirti polifenolinių junginių, juglono kiekį ir įvertinti antioksidantinį aktyvumą. Metodai: Pagaminta pradinė homeopatinė tinktūra (urtinktūra) ir jos skiediniai pagal Homeopatijos farmakopėjos reikalavimus (HAB 2000, 3a taisyklė). Spektrofotometriškai nustatytas polifenolinių junginių... [toliau žr. visą tekstą] / Preparations referred to as homoeopathic are those made of homoeopathic raw materials using homoeopathic manufacturing procedures. In order to measure biological activity of homoeopathic preparations scientists use the same investigation methods as with other kinds of chemical products [30]. For this study homoeopathic tincture of black walnut (Juglans nigra L.) shell and its D1and C1 dilutions have been selected as these produce low-grade solutions in which active substances still can be identified and concentrations as well as bioactivity can be assessed by available methods of testing. The scientific literature sources state that the black walnut shell contains nine basic chemical substances [29]. It is found that one of the basic active ingredients is juglone which possesses cytotoxic properties effective against melanoma, the liver, lung, heart and blood cells. [25,28,38,39]. As the studies of black walnut preparations are not so common, we have chosen to investigate the juglone amount and polyphenolic compounds in solutions and to measure their antioxidant properties. The aim of the research: To produce homoeopathically original tincture of the black walnut shell and its D1 and C1 dilutions, to explore polyphenolic compounds, the level of juglone and evaluate their antioxidant activity. The methodology: Original homoeopathic tincture (urtincture) and its solutions were produced following the specification of Homoeopathy Pharmacopoeia (HAB 2000, rule 3a)... [to full text]
3

Effects of Black Walnut and Honey Locust on Forage Growth, Soil Water, and Soil Quality Indicators

DeBruyne, Scott Alexander 30 March 2009 (has links)
The goal of this research was to determine the interactions between forage and tree components of a silvopasture system. Two studies were performed on adjacent sites established in 1995 at Virginia Tech's Kentland Research Farm. The objectives of the studies were to: 1. Determine the influence of honey locust and black walnut silvopastures on indicators of soil quality when compared to open pasture. 2. Determine if silvopasture systems changed forage mass production and soil water compared to open pastures. The study on soil quality indicators was performed in a previously grazed silvopasture. Samples were collected from the upper 15 cm of soil at three distances from the tree rows. Total N (p= 0.0219), total C (p= 0.0216), extractable P (p= 0.063), extractable K (p= 0.0347) and microbial organic C (p= 0.0255) were greater in honey locust silvopastures. The highest concentration of soil nutrients and best soil physical and chemical properties were observed 1.5 m from the tree stem. Forage growth and soil water were measured in silvopastures in 2006 and 2007. In 2006 there was higher forage growth in the black walnut and honey locust than beneath 70% shade cloth. In 2007, with a 50% shade cloth, forage growth was similar in all treatments. Initial soil water content was highest under shade cloth in 2006. In 2007 the rate of soil drying was lowest beneath the shade cloth. The presence of trees did not negatively effect forage growth and silvopasture systems improved the soil quality indicators compared to open pasture. / Master of Science
4

Analyses of ribosomal DNA internal transcribed spacer sequences from Juglans nigra and leaf-associated fungi in Zoar Valley, NY

Ragozine, Vincent Kyle 06 June 2008 (has links)
No description available.
5

Variabilité morphologique et architecture de deux espèces de noyers : Juglans regia L., Juglans nigra L. et de deux noyers hybrides interspecifiques

Sabatier, Sylvie 14 December 1999 (has links) (PDF)
L'analyse architecturale et l'analyse statistique de la morphologie des pousses annuelles ont permis de caractériser les modes de croissance (préformation, néoformation et polycyclisme) et de ramification des Noyers au cours de leur développement. Les Noyers étudiés sont Juglans regia, Juglans nigra et de deux de leurs hybrides interspécifiques, Juglans major 209 x Juglans regia et Juglans nigra 23 x Juglans regia. Au cours du développement des Noyers, l'évolution des valeurs des paramètres de croissance et de ramification s'effectue de manière précise selon des gradients morphogénétiques connus. Les variations morphologiques interspécifiques reposent essentiellement sur la répartition des rameaux sur les pousses annuelles végétatives et sur la direction de croissance des branches sur le jeune arbre. Elles sont dues à la structure des modules et au moment d'expression de la réitération immédiate, processus déterminant l'édification de la cime, sur l'arbre adulte. Les facteurs du milieu modifient de manière quantitative les étapes de différenciation morphologiques spécifiques. La connaissance de critères morphologiques susceptibles d'être sous contrôle génétique est essentiel en amélioration et sélection des arbres. Les caractèristiques morphologiques des pousses annuelles évoluent de manière précise et ordonnée en fonction de la position architecturale et au cours de l'ontogènie des arbres. Ces résultats peuvent être la base d'une meilleur connaissance des bases physiologiques de l'architecture de l'arbre.
6

Etude écophysiologique de l'endurcissement au gel des arbres

Poirier, Magali 26 September 2008 (has links) (PDF)
L'impact des conditions estivales de croissance (défoliation, stress hydrique, carence azotée) sur la résistance au gel des différents organes de l'arbre, en liaison ave c leur statut carboné, a été étudié chez le noyer (Juglans regia). La comparaison de plusieurs méthodes estimant la résistance au gel montre que GélistaTM, une nouvelle technique pour estimer l'endurcissement au gel à partir des variations de diamètre des rameaux, indique seulement une gamme de sensibilité au gel. Le test de fuite des électrolytes montre une plus grande sensibilité dans la détermination de la température de résistance au gel. Ensuite, l'étude des corrélations entre le LT50 et les différentes variables (sucres solubles, humidité pondérale et moyenne des températures minimales journalières sur les 15 jours qui précèdent le prélèvement) a permis de construire un modèle simple pouvant prédire le niveau de résistance au gel des rameaux d'un an pour deux variétés de noyers adultes (Franquette et NG38). L'étude du développement aérien végétatif montre que le potentiel d'adaptation (plasticité morphologique) des arbres aux contraintes culturales est plus faible en fin de saison estivale de croissance. Les traitements ont eu un impact sur la structure, la biomasse totale et structurale, ainsi que sur les réserves glucidiques. En général, les traitements ont provoqué une diminution plus ou moins forte de la mise en réserve glucidique dans les différents organes. Par ailleurs, l'analyse des impacts des conditions estivales de croissance sur la résistance au gel a mis en évidence une correlation forte et négative entre le LT50 et la teneur en GFS dans les organes aériens. Pour les organes souterrains, elle existe également mais elle est plus faible. Enfin, pour les rameaux de l'année, l'ensemble des résultats obtenu sur de jeunes noyers en conteneur a été vérifié sur des noyers adultes.
7

<b>HYPERSPECTRAL CHARACTERIZATION OF FOREST HEALTH</b>

Sylvia Park (19203892) 26 July 2024 (has links)
<p dir="ltr">Reflectance spectroscopy has been increasingly used in forestry due to its ability to rapidly, efficiently, and non-destructively detect tree stress, enabling timely and cost-effective forest management decisions. This dissertation synthesizes three studies and five experiments to understand and improve our ability to use spectral data to estimate a variety of foliar physiochemical traits and identify spectral responses in multi-stress environments, thus, advancing our understanding and application of hyperspectral data in forest management.</p><p dir="ltr">The first study seeks to refine the hyperspectral approach to monitoring tree stress by selecting optimal wavelength ranges to enhance the estimation of foliar traits, such as CO<sub>2</sub> assimilation rate, specific leaf area, leaf water content, and concentrations of foliar nitrogen, sugars, and gallic acid. The study revealed that model performance varied significantly across the different wavelength ranges tested and consistently, including longer wavelength regions improved trait estimation for all traits modeled. This research also established a framework for discovering novel or previously unknown absorption features associated with functional traits, thereby laying the groundwork for expanded spectral applications. This advancement enables the estimation of diverse foliar traits and facilitates detailed stress detection in trees.</p><p dir="ltr">The second study focuses on assessing the effectiveness of hyperspectral data in estimating foliar functional trait responses to various biotic and abiotic stressors and to differentiate those stressors in black walnut (<i>Juglans nigra </i>L.) and red oak (<i>Quercus rubra</i> L.) seedlings. We demonstrated that spectral data can reliably estimate a wide range of foliar traits, highlighting its potential as a surrogate for reference data in understanding plant responses to stress. This research revealed that spectral leaf predictions can effectively provide stress-specific insights into tree physiochemical responses to biotic and abiotic stressors.</p><p dir="ltr">The third study explores the application of hyperspectral reflectance to identify drought-induced foliar responses in black walnut seedlings during their initial field establishment. Chemometric models developed from greenhouse experiments were applied to spectral data collected in the field to assess their transferability and accuracy in predicting various leaf traits under drought stress. Using only spectral data, we demonstrated that seedlings show distinct spectral responses to past and ongoing drought stress, with varying degrees depending on seed provenances. This research aims to provide practical insights for utilizing spectral analysis in real-world conditions and understanding the challenges of using spectral tools in the field.</p><p dir="ltr">Collectively, this dissertation demonstrates the robust potential of hyperspectral reflectance technology in advancing the monitoring of tree health. By optimizing spectral range selection, reliably estimating tree foliar traits under stress conditions, differentiating various stressors in controlled environments, and effectively detecting current and past drought stress in field conditions, this research offers valuable insights for improving forest health monitoring and management strategies in response to environmental challenges.</p>

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