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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.
21

Propagação in vitro e aspectos anatômicos e ultraestruturais da calogênese em Campomanesia adamantium / Propagation in vitro and anatomic and ultraestructural aspects of callogenesis in Campomanesia adamantium

Rossato, Marieli 04 February 2015 (has links)
Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-03-10T19:58:47Z No. of bitstreams: 2 Dissertação - Marieli Rossato - 2015.pdf: 1478784 bytes, checksum: a2e927078a0e03d9ccd322d3fbb3c4bb (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-14T15:21:51Z (GMT) No. of bitstreams: 2 Dissertação - Marieli Rossato - 2015.pdf: 1478784 bytes, checksum: a2e927078a0e03d9ccd322d3fbb3c4bb (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-14T15:21:51Z (GMT). No. of bitstreams: 2 Dissertação - Marieli Rossato - 2015.pdf: 1478784 bytes, checksum: a2e927078a0e03d9ccd322d3fbb3c4bb (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The aim of this work was to obtain protocol for Gabirobeira propagation in vitro and characterize anatomical and ultrastructure calogenesis. In the first experiment, shoots were induced in vitro, using culture medium WPM (Wood Plant Medium) with differents concentrations of 6-benzilaminopurine (0; 0,25; 0,5; 1,0 and 2,0 mg L-1), in the influence or not active photosynthetically radiation. In the second experiment, root formation was induced using different concentration (0; 0,5; 1,0; 1,5 and 2,0 mg L-1) of indolbutyric acid (IBA), naphthaleneacetic acid (NAA) and indoleacetic acid (IAA). The experimental design was completely randomized with 5 repetitions (each replication consisted of three tubes), with the factorial 2x5 for shoot multiplication (two environments and five concentrations). In the third experiment, callus were induced in nodal segments using different concentrations (0; 1,0; 2,0 and 4,0 mg L-1) of IBA, NAA, IAA, 2,4-diclorofenoxiacetic and Picloram. The concentration indicated for shoot induction is 1,0 mg L-1 kept in the dark for elongation. On the rooting experiment was not possible develop protocol for root formation. Callus were induced in all concentrations, except in the control, but 1,0 mg L-1 de picloram was more efficient. Through the showth curve of callus anatomic cuts and ultrastructural analysis, we can infer that after 28 days the callus should be transferred to new media culture since during it was possible to visualize the formation of meristematic center highlighting the periphery. / Objetivou-se o desenvolvimento de protocolo de propagação in vitro de Gabirobeira a partir de segmentos nodais e caracterizar anatômica e ultraestruturalmente a calogênese. No primeiro experimento, brotações foram induzidas in vitro, utilizando-se meio de cultura WPM (Wood Plant Medium) com diferentes concentrações de 6-benzilaminopurina (0; 0,25; 0,5; 1,0 e 2,0 mg L-1), na presença ou não de radiação fotossinteticamente ativa. No segundo experimento, rizogênese foi induzida utilizando diferentes concentrações (0; 0,5; 1,0; 1,5 e 2,0 mg L-1) de ácido indolbutírico (AIB), ácido indolacético (AIA) e ácido naftalenoacético (ANA). O delineamento estatístico foi inteiramente casualizado com 5 repetições (cada repetição composta por 3 tubos) nos dois experimentos, sendo para as brotações esquema fatorial 2x5 (dois ambientes e cinco concentrações). No terceiro experimento, calos foram induzidos em segmentos nodais utilizando-se diferentes concentrações (0; 1,0; 2,0 e 4,0 mg L-1) de AIB, AIA, ANA, 2,4-diclorofenoxiaéctico e Picloram. A concentração indicada para indução de brotações é 1,0 mg L-1 de BAP mantida no escuro para que ocorra alongamento. Com os tratamentos testados não foi possível obter protocolo eficiente para rizogênese. Calos foram induzidos em todas as concentrações testadas, exceto na testemunha, porém 1,0 mg L-1 de picloram foi mais eficiente. Através da curva de crescimento do calo juntamente com as análises histoquímicas e ultraestruturais, é possível inferir que ao 28º dia os calos devem ser transferidos para novos meios de cultura, visto que durante este período é possível visualizar a formação de centro meristemático se destacando da periferia.
22

Whole plant response to soil compaction : from field practices to mechanisms

Montagu, Kelvin D., University of Western Sydney, Hawkesbury, Faculty of Agriculture and Horticulture, School of Horticulture January 1995 (has links)
This thesis examines the growth response and inter-relationships between shoots and roots of plants grown in compact soil. In the field, two topsoil and two subsoil conditions were created with five vegetable crops sequentially grown. Between 6 and 12% of the root system grew in the compact subsoil, which had a soil strength of 3.1 c.f. 1.9 MPa in the loosened subsoil. Both the root length density (Lv) and the specific root length were lower in the compact subsoil (80% and 30%, respectively). This had no effect on shoot growth when water and nutrients were well supplied. Compensatory root growth in the lose soil above the compact subsoil occurred in broccoli plants. As a result plants grown in soil with or without a compact subsoil had a similar total root length but with altered root distribution. When the water and nitrogen supplied to the soil was reduced, the lower subsoil Lv in the compact subsoil did not restrict water or N acquisition. This was possibly due to a large increase in the specific uptake per unit length of root, by the fewer roots in the compact subsoil. Compared to the subsoil treatments, only small changes in topsoil physical properties occurred when tillage was ceased. From the field trials the proportion and time of root growth into compact soil appeared important in determining the plant response. In a series of split-root experiments (horizontal and vertical arrangements of compact and loose soil) compensatory root growth in the loose soil only occurred when the root system was exposed to horizontally compact soil When compensatory root growth did not occur shoot growth was reduced. This resulted in there being a close relationship between total root length and leaf area. Further test results support a direct effect of mechanical impedance on shoot growth with a rapid (within 10 minutes) and large (50%) reduction in leaf elongation occurring when roots were mechanically impeded. In the field only plants whose roots were totally exposed to compact soil had reduced shoot growth with very compact subsoil having no effect. / Doctor of Philosophy (PhD)
23

The effect of partial rootzone drying on the partitioning of dry matter, carbon, nitrogen and inorganic ions of grapevines.

Du Toit, Petrus Gerhardus January 2005 (has links)
Partial rootzone drying (PRD) is an irrigation management technique designed to reduce water use in grapevines without a decline in yield, thereby increasing water–use efficiency (measured as t/ML) (WUE). The principle of PRD is to keep part of the root system at a constant drying rate to produce soil-derived signals to above–ground plant organs to induce a physiological response. Major PRD effects include a reduced canopy size and greatly increased WUE with possible improvements in fruit quality. Although we have a good understanding of the hormonal physiology of PRD, little is known on the effect of PRD on partitioning of C, N and inorganic ions such as K. This thesis broadens our knowledge on the effects of PRD on grapevine field performance, growth and dry matter accumulation as well as its effects on physiology and biochemistry. In field experiments over 3 seasons, PRD reduced water use in grapevines without a significant decline in yield. PRD effects included reduced shoot growth and greatly increased WUE. Field–grown Cabernet Sauvignon, where the PRD grapevines were irrigated at half the control rate, and Shiraz where the PRD grapevines were irrigated at same rate as controls, confirmed that PRD is not simply an irrigation strategy that applies less water, rather it alters the way in which the plant responds to its environment, e.g. PRD alters the sensitivity of the stomatal response to atmospheric conditions and significantly influence enzymes that regulate nutrient accumulation and partitioning. PRD did not change the total amount of carbon and nitrogen on a whole plant basis. However, it caused a significant partitioning of carbon and nitrogen towards trunk, roots and fruit at the expense of shoot growth. This change in partitioning occurred as a result of altered activity of the enzymes controlling the assimilation of carbon and nitrogen. PRD significantly reduced nitrate reductase (NR) activity in grapevine leaves, which catalyses the first step in the assimilation of nitrate irrespective of the amount of water applied. The reduction in NR activity is correlated with the development of the PRD cycle and the associated reduction in stomatal conductance. PRD also significantly altered grapevine sucrolytic enzyme activity that regulate source:sink relationships. PRD showed transient increases in leaf sucrose phosphate synthase (SPS) activity (formation of sucrose) compared to control, but significantly reduced leaf neutral invertase (sucrose cleavage) and leaf starch content in both field and potted experiments. This may indicate an increased photosynthetic capacity and a reduction in its sink strength for sucrose in favor of organs such as fruit and roots. This hypothesis was reinforced by the fact that berries showed significantly higher levels in glucose and fructose early in the season. Berry sugar content and Brix at harvest however was unaffected. Although PRD had no significant effect on berry characteristics at harvest such as Brix and pH, it occasionally reduced per berry K+ content and increased total amino acid concentration that may lead to positive outcomes for wine quality. PRD–treated grapevine roots on the 'wet'– and 'drying'–sides differed greatly in enzyme activity and osmolality. PRD significantly increased osmolality in both wet and drying roots by increasing total osmolyte concentration that may facilitate the movement of water from wet to dry roots. The increases in osmolality were also associated with increased free polyamine production (spermidine and spermine) in PRD roots that may be related to increased root growth and density. / Thesis (Ph.D.)--School of Agriculture and Wine, 2005.
24

Paprastųjų uosių (Fraxinus excelsior L.), besiskiriančių džiūvimo laipsniu, palikuonių išauginimas in vitro ir genetinės įvairovės įvertinimas / In vitro cultivation and genetic research of common ash (Fraxinus excelsior L.) seedlings descended from the trees with different drying rates

Masiokas, Andrius 21 June 2010 (has links)
Darbo objektas – Alyvmedinių (Oleaceae) šeimos uosinių (Fraxinus) genties medis - paprastasis uosis (Fraxinus excelsior L.). Darbo tikslas – Išauginti in vitro paprastųjų uosių (Fraxinus excelsior L.), besiskiriančių džiūvimo laipsniu, palikuonis ir atlikti genetinės įvairovės įvertinimą. Darbo metodai – regeneravusių mikroūglių įvertinimas, palikuonių DNR nustatymas. Darbo rezultatai. Atlikus tyrimus įvertintos paprastojo uosio išauginimo in vitro sąlygos ir nustatyta genetinė įvairovė. Eksplantų sterilinimui tikslinga naudoti aseptinių tirpalų kombinaciją su „ACE“ ir AgNO3 0,2 proc., kad užtikrinti gyvybingų ir be užkrato eksplantų išlikimą. Aktyviausiai mikroūgliai regeneravo WPM (Woody Plant Medium) terpėje, kurios pH 5,0. Gyvybingiausi regenerantai atitinka mažiausiai pažeistą uosį pagal džiūvimo laipsnį. Sveikiausio genotipo uosių ex vitro sąlygomis adaptavosi 92 proc., labiausiai pažeisto - 53 proc. Tirtų dviejų paprastojo uosio individų turėjo skirtingus APPD fenotipus su naudotais dviem informatyviais pradmenimis. / The research object. – Oleaceae (Oleaceae) family of Ash (Fraxinus) tree of the genus - ash (Fraxinus excelsior L.). The aims of the study – Grown in vitro for common ash (Fraxinus excelsior L.), distinguished by the degree of drying, and a descendant of the genetic diversity assessment. Methods – regenerant microshoots evaluation of DNA detection. The results. After the tests evaluated in plain ash grown in vitro conditions and the genetic diversity. For explants sterile appropriate to use a combination of aseptic solutions with ACE and 0.2 percent AgNO3. to ensure the viability and survival of the explants without contamination. The most active shoots regenerate WPM (Woody Plant Medium) medium with pH 5.0. The most lively regenerants the least damaged ash according to the degree of drying. Healthiest genotype ashes of ex vitro specialized 92 percent. The most damaged - 53 percent. The results from two-ordinary ash individuals had different phenotypes APPD to use two informative primers.
25

Recirculating hydroponic systems : evaluating cuttings yield and rooting ability of cold tolerant eucalyptus hybrids.

Wallis, Jacqueline Tanya. January 2004 (has links)
In South Africa, clonal forestry of Eucalyptus and its hybrids has been implemented to increase the productivity on existing forestry lands and marginal sites and to facilitate the production of desired fibre types for timber processing operations. The cold-tolerant Eucalyptus grandis x E. nitens hybrids have produced consistently high yields, and are propagated clonally with limited success via a macro-cutting system currently in use for other hybrid species. The heart of vegetative propagation operations is the clonal hedge and its management, and nutrition in particular, is an important element of any vegetative propagation programme. However, achieving and sustaining an optimum nutritional balance in macrohedges is difficult in practice and, in order to accurately predetermine the optimum plant nutrition required all year round and to ensure optimal levels of rooting, a more controllable nutrient environment is essential. Hydroponics may facilitate this control of nutrition. At the same time it may be possible to manipulate the system to determine accurately what levels of each nutrient may contribute to the highest rooting and more importantly allow forest nursery managers to maintain those levels in a practical manner. The main aims of the present work were to obtain and compare cuttings and rooting yields from hydro-ramets in different hydroponic substrates and systems and to investigate the possible roles of essential nutrients on those parameters. Modified Nutrient Film Technique (NFT), ebb-and-flow and aeroponic tables were used in this study. The former consisted of eight individual gutters, allowing for eight different substrates to be tested simultaneously. One gutter was set up as an unmodified NFT table and the other seven gutters had gravel, Leca, peat, perlite, perlite: vermiculite mix, Rockwool® and sand as substrates; all were supplied with the same nutrient solution. Three commercial clones were used throughout these trials: GN107, GN156 and NHOO. Rooting results and data from plant elemental analyses indicated that certain elements (Ca, Cu, Zn, Mn and B) appeared to play a more important role in rooting than others (N, P, K, Mg, Na and Fe). It was also found that when comparing the hydroponic systems, the substrate and / or method of irrigation affected the availability and uptake of different nutrients, which in turn affected the rooting of coppice collected from those ramets. The rooting performance of coppice from the eight different substrates tested in the NFT system was compared. Within each of the four harvests undertaken, both clone and substrate had a significant effect on the rooting performance. However, when the four harvests were compared, only harvest number/time had a significant effect on the rooting performance of the cuttings derived from the hydro-hedges . For both the ebb-and-flow and aeroponics systems (where there was no substrate), only the clone had a significant effect on the rooting performance. In addition to this, the plants from the ebb-and-flow system produced the highest number of cuttings to be placed overall (7.9 cuttings per mother plant per harvest) while those from the gravel substrate had the highest rooting percentage overall (26.9 %). When combining these two factors into a success rate, the perlite substrate rated highest (1.7 rooted cuttings per mother plant per harvest). From a cost efficiency perspective, perlite was the most cost effective substrate, as it required the least initial capital outlay to produce one million rooted clones per year from a hydroponics system (R6 533 655). The plants in the perlite substrate also produced the highest number (6 700) of rooted cuttings per year from 1 000 mother plants with a low cost per plant (R2.33 per rooted plant). / Thesis (M.Sc.)-University of KwaZulu- Natal, Durban, 2004.
26

The development of in vitro rooting systems for cold-tolerant Eucalyptus grandis x nitens clones and the assessment of the hydraulic efficiency of roots produced by in vitro vs. cutting propagation.

Mokotedi, Mompe Edward Oscar. January 1999 (has links)
Hybrid clones of the fast-growing Eucalyptus grandis and cold-tolerant E. nitens (GN clones) have been identified by the South African Forestry Industry as being highly suitable for plantations in cold-dry marginal areas. However, one of the main problems regarding their propagation is the difficulty in rooting of cuttings, both in vitro and ex vitro. The aims of this investigation, therefore, were (1) to develop widely applicable and efficient in vitro rooting system(s) for these commercially important clones, and (2) to assess some physiological characteristics of the roots produced. Adventitious shoots (15-20 mm in length) were obtained (l0 shoots/explant) from axillary buds on Murashige and Skoog's (MS) medium containing 0.01 mg.l-1 NAA, 0.01 mg.l-1 IBA and 0.2 g.l-1 FAP. The effect of various medium components, as well as modification of culture environment on in vitro rooting, were investigated. The highest rooting frequencies in clones GN121 (75%) and GN107 (65%) were achieved on l/4 MS with additional 0.22 g.l-1 CaCl2..2H2O and 0.18 g.1-1 MgS04.7H2O, 0.1 mg.l-1 IBA, 0.1 mg.l-1 biotin, 0.1 mg.l-1 calcium pantothenate, 15 g.1-1 sucrose and 4 g.l-1 Gelrite. Best culture conditions were an initial 72-hours dark incubation followed by a 16-hours day/8-hours night photoperiod at a PPFD of 37 µmol.m-2.s-1 and 23°C day/21°C night for seven days, after which the PPFD was increased to 66 µmol.m-2.s-1 at 27°C day/21°C night for 18 days. Towards the development of a more widely applicable in vitro rooting protocol for GN clones, the use of Agrobacterium rhizogenes strains was investigated. Production of transgenic roots was observed on carrot discs and shoots from seedlings of Eucalyptus grandis and E. nitens, but not on shoots of GN clones. Therefore, a method needs to be established for the successful transfer and integration of the Ri plasmid of Agrobacterium into the hybrid plant genome for induction of transgenic roots. The quality of roots produced in vitro and from cuttings was assessed by examination of root anatomy and hydraulic characteristics. Adventitious roots were prepared for measurement of hydraulic conductivity by detopping explants, then filtered, acidified distilled water was drawn through undisturbed potted root systems under partial vacuum, causing no damage to the roots. Initial studies showed that tissue culture-derived roots exhibited a higher specific root mass hydraulic conductivity than those derived from cuttings (6.46 x 10-6 vs. 3.06 X 10-6 g.kPa-1.s-1.g-1 dry root), probably due to root architecture. Curves relating vulnerability to water potential were constructed and both types of roots showed vulnerability to cavitation at high water potentials. Differences were also observed in staining reactions (safranin and fastgreen) which might suggest differences in presence and level of secondary metabolites in these roots at the juvenile stage. Applications of the developed protocols and future research strategies are discussed. / Thesis (M.Sc.)-University of Natal, Durban, 1999.
27

Veiksniai, lemiantys Sedum L. pridėtinių ūglių formavimąsi in vitro / Factors determining adventitious shoot formation in vitro in Sedum L

Klimaitienė, Erika 13 June 2012 (has links)
Magistrantūros studijų baigiamajame darbe pateikiama šilokų pridėtinių ūglių regeneracija lapų segmentų kultūroje, priklausomai nuo genotipo ir augimo reguliatorių maitinamojoje terpėje. Darbo objektas – Sedum rupestre ‛Angeline’, Sedum reflexum ‛Cristatum’, Sedum fosterianum ‛Elegans’, Sedum maximum ‛Autumn Joy’ lapų audiniai. Darbo metodai: izoliuoti eksplantai auginti Murashige ir Skoog (MS) maitinamojoje terpėje su skirtingais augimo reguliatorių kiekiais. Susiformavę pridėtiniai ūgliai įšaknydinti MS maitinamojoje terpėje su skirtingais augimo reguliatorių kiekiais. Vertintas ūglių susiformavimo dažnis (%), ūglių kiekis iš eksplanto (vnt.) ir įsišaknijimo dažnis (%). Darbo rezultatai. Veislių ‛Elegans’ ir ‛Cristatum’ ūglių susiformavimo dažnį labiausiai skatino 0,75 mg l-1 BAP. Veislės ‛Angeline’ didžiausias ūglių susiformavimo dažnis nustatytas terpėje, papildytoje 3,0 mg l-1 BAP. Veislės ‛Autum joy’ izoliuoti lapo segmentai 100 % dažniu ūglius formavo terpėse su 3,0 mg l-1 BAP + 0,5 mg l-1 NAR ir 4,0 mg l-1 BAP + 0,5 mg l-1 NAR. Veislės ‛Elegans’ didžiausias ūglių kiekis eksplantui gautas terpėje papildytoje 0,75 mg l-1 BAP. Veislės ‛Angeline’ daugiausia ūglių iš eksplanto susiformavo terpėse su 0,75 mg l-1 BAP ir 3,0 mg l-1 BAP. Terpėje, papildytoje 3,0 mg l-1 BAP gautas didžiausias veislės ‛Cristatum’ ūglių kiekis vienam eksplantui. Veislės ‛Autum joy’ eksplantai daugiausia ūglių suformavo terpėse, papildytose 3,0 mg l-1 BAP + 0,5 mg l-1 NAR ir 4,0 mg l-1 BAP + 0,5... [toliau žr. visą tekstą] / The master work presents orpine adventitious shoots regeneration in leaves segments cultures, depending on genotype and growth regulators in the culture medium. Object of the work – Sedum rupestre ‛Angeline’, Sedum reflexum ‛Cristatum’, Sedum fosterianum ‛Elegans’, Sedum maximum ‛Autumn Joy’ leaves tissues. Method of the work – isolated explants were growing on Murashige ir Skoog (MS) nutrition medium with different content of growth regulators. Adventitious shoots were transferred to MS culture medium for rhizogenesis induction. Shoots formation frequency, number of shoots per explant and rooting frequency were evaluated. The results of work. The highest shoots formation frequency of orpine varieties ‛Elegans’ and ‛Cristatum’ has been obtained under influence of 0.75 mg l-1 BAP. The 3.0 mg l-1 BAP concentration in culture medium resulted in highest shoots regeneration frequency of variety ‛Angeline’. All isolated explants of ‛Autum joy’ formed adventitious shoots in the medium supplemented with 3.0 mg l-1 BAP + 0.5 mg l-1 NAA and 4.0 mg l-1 BAP + 0.5 mg l-1 NAA. While 0.75 mg l-1 BAP in culture medium stimulated shoots formation frequency of variety ‛Elegans’. The highest shoots number per explant of variety ‛Angeline’ has been establishing in medium with 0.75 mg l-1 BAP and 3.0 mg l-1 BAP. Medium supplemented with 3.0 mg l-1 BAP resulted in highest shoots number per explant of ‛Cristatum’. Explants of variety ‛Autum joy’ highest shoots number per explant formed in medium... [to full text]
28

Effects of irradiation and temperature on shoot growth and development in Blue holly (Ilex x meserveae) /

Kosiba, Andrea, January 2005 (has links) (PDF)
Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.
29

Root-to-shoot communication in response to drought : a comparison of four central hardwood tree species /

Loewenstein, Nancy J., January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 185-200). Also available on the Internet.
30

Root-to-shoot communication in response to drought a comparison of four central hardwood tree species /

Loewenstein, Nancy J., January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 185-200). Also available on the Internet.

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