DOCSLIB.ORG

Asexual Propagation of Plants Introduction - Asexual Propagation of Plants

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Asexual Propagation of Plants Introduction - Asexual Propagation of Plants ASEXUAL PROPAGATION OF PLANTS INTRODUCTION - ASEXUAL PROPAGATION OF PLANTS Asexual propagation has been widely used within the plant sciences as a method of maintaining genetic purity. Most of the uses have been within horticulture, although we do have examples in both forages and agronomic cropping systems. We have also found this to be an efficient method of maintaining some botanical varieties. When using asexual propagation, we are essentially producing clones. Clones are groups of plants that are identical to their parent (or donor) plant. We also use this process for plant types that can only be propagated asexually. Several classic examples of these are the Bartlett pear and the Red Delicious apple. The specific genetic composition has been asexually propagated for many years. Major methods of asexual propagation of stems and leaves are cuttings, layering, division, and grafting. We also find the production of specialized plant parts that allow for asexual propagation. One of the widely used plant parts are the production of modified stems. These can be found in the form of tubers, bulbs, rhizome , corms and stolons. Although less frequent, we do find the use of root tissue for plant propagation. LEARNING OUTCOMES 1. Understand the importance of economically important, asexually propagated species and the unique characteristics or each type of classification. 2. Be able to correctly use the terminology and identify the structures of the asexually propagated plant parts that are commonly found in horticultural species. 3. Learn the proper methods associated with asexually propagating economically important plant species. Advantages of vegetative reproduction Since higher levels of stored reserves are available throughout the year and the parent plant with its root system can absorb water from quite a wide area, two of the hazards of seed germination are reduced. Buds are produced in an environment where the parent is able to flourish, but many seeds dispersed from plants never reach a suitable situation for effective germination. Vegetative reproduction does not usually result in rapid and widespread distribution of offspring in the same way as seed dispersal, but tends to produce a dense clump of plants with little room for competitors between them. Such groups of plants are very persistent and, because of their buds and underground food stores, can still grow after their foliage has been destroyed by insects, fire, or cultivation. Those species regarded as weeds are difficult to eradicate, since even a small piece of an asexual propagule bearing a bud can give rise to a new colony (clone). The following sections will describe the diversity of methods and/or structures that can be used for the process of asexual reproduction. SEPERATION Separation is the propagation method in which these natural structures are simply removed from the parent plant and planted to grow on their own. Crown division is one method and one of the best methods to propagate herbaceous perennial plants (Figure 1). With this process, the plant is simply cut into sections with a knife. Individual growing points (shoots) that contain roots may then be used be used to form new plants. Some woody perennials that branch or sucker (adventitious shoots) from the main plant can also be reproduced in this way. A B C Figure 1. Example of an asexual propagation called separation: (A) Large, mature plant that can be separated into multiple shoots with adventitious roots, (B) several stems with roots that have been removed, and (C) new plant is potted. PROPAGATING PLANTS BY GRAFTING (OR BUDDING) Grafting and budding are used as one of the primary methods of propagating certain plants such as fruit trees (illustrated in Figure 2). Grafting is a horticultural technique whereby plant parts from one plant are attached onto those of another so that the two plant types join together. In most cases, one plant is selected for its root characteristics and this is called the stock or rootstock The other plant is selected for its vegetative characteristics such as stem, leaf, flower or fruit and is called the scion. LAYERING A simple method where the potential cutting(s) is (are) attached to the plant until the adventitious roots form is called layering (Figure 3). This is done by covering the developing rooting areas with some form of media such as soil , sand, or a potting mix. This allows for nutrients from the stock plant to supplement growth until the ‘cutting’ can be detached producing functional plants. A variation of this procedure is air layering (Figure 4). This is done by taking a stem and covering 1 – several nodes with a media until such a time that we get the formation of adventitious roots. The stem can then be severed from the stock plant and establish a new cutting. Figure 2. Illustration of the grafting process with a separate rootstock and a scion. Figure 4. Illustration of the air layering process. Figure 3. Illustration of the layering process. CUTTINGS This method of asexual propagation is one of the most popular techniques due to the limited resources that are needed and it’s efficient use on various landscaping, fruit, and vegetable plants. A cutting is a vegetative plant part which is severed from the parent plant in order to produce a plant that is genetically identical to the donor (Figure 5). There are a number of various methods that fall under this classification. Cuttings may be taken at any time on herbaceous plants but may vary with perennial plants. At least one node should be below the media surface since many plant types will produce roots with this plant part, but some plants can root at the internodes. Some of the variation within this procedure are the tip cuttings (stem cutting which includes the terminal bud), cane cuttings (stems are cut into sections containing one or two nodes), or leaf cuttings (may be a whole leaf with or without the petiole or leaf sections). VEGETATIVE PLANT STRUCTURES Another major area is the natural production of vegetative plant structures that have the capacity to produce new plants. Asexual propagation, as mentioned earlier, is the best way to maintain some species, particularly an individual that best represents that species. Many of these vegetative structures are modified stems and include structures produced below the soil line (bulbs, corms, rhizomes, and tubers) and above the soil (stolons). Many of these serve as food storage areas for the plant. Each of the major types of vegetative plant structures will be described. STOLONS A stolon is a horizontal stem that can root and produce new adventitious roots (Figure 6). A term that is also used is a runner . Plants that produce stolons or runners are propagated by initiating the production of adventitious roots and then removing the plantlet from the maternal plant. Plantlets can also be initiated at the tips of stolons and form roots while still attached to the parent (spider plant) or detached and placed in a rooting medium. Examples: strawberry, spider plant, bermudagrass. BULBS Bulbs consist of very short stems with closely packed leaves arranged in concentric circles round the stem. The leaves are swollen with stored food e.g. onion (Figure 7). A terminal bud will produce the next A B C D E Figure 5. Examples of cuttings: stem cutting (A, B, &D) and a leaf cutting (C & E). A B C Figure 6. Examples of several plant types that reproduce asexually by means of a modified stem called a stolon: (A) strawberries showing a plant producing stolons and inset a stolon without the production of adventitious roots and a mature plantlet with adventitious roots. (B&C) A plantlet and a mature spider plant. year’s flowering shoot and the lateral (axillary) buds will produce new plants. There are also a number of flowering bulbs that are used in the horticultural industry. RHIZOMES Rhizomes are stems which grow horizontally under the ground. In some cases, the underground stems are swollen with food reserves. The terminal bud turns upwards to produce the vegetative shoot and A B A C D Figure 7. Example of a simple bulb (Allium cepa). A mature bulb (A) and a X-section (B) showing the modified leaves. An immature bulb (C) showing the production of adventitious roots and a X-section of the immature growth (D). the lateral buds may grow out to form new rhizomes. This tissue typically has stored reserves. At each node we find an axillary bud covered by a leaf scale. This tissue has the ability to produce a shoot and adventitious roots. If a rhizome is cut into pieces with at least one node, this may allow for the production of a new plant. A B C Figure 8. Examples of a rhizome producing plant. (A) A sedge (Cyperus spp.) producing a plant from the activity of a rhizome. (B) A rhizome from a johnsongrass plant (Sorghum halepense) with the individual rhizome with a functional plant with leaves and adventitious roots (C) and rhizomes with developing shoots prior to emergence. A B C Figure 9. An example of a bermudagrass plant that produces both a stolon (A) and a rhizome (B&C). TUBERS Tubers are thick, underground stems that develop at the end of rhizomes (Figure 10). The tuber has all the parts of a normal stem including nodes and internodes. The nodes are the ‘eyes’, and they are arranged around the tuber in a spiral fashion beginning on the end opposite the attachment point to the rhizome. A tuber will typically have a form of stored reserves in cells classified as parenchyma. The tuber is produced in one growing season and is a means of propagation. One of the best examples of a tuber is the potato (Solanum tuberosum).
Load more

Recommended publications
  • Relative Importance of Propagule Size and Propagule Number for Establishment of Non-Indigenous Species: a Stochastic Simulation Study
    Aquatic Invasions (2016) Volume 11, Issue 1: 101–110 DOI: http://dx.doi.org/10.3391/ai.2016.11.1.11 Open Access © 2016 The Author(s). Journal compilation © 2016 REABIC Research Article Relative importance of propagule size and propagule number for establishment of non-indigenous species: a stochastic simulation study 1,2 3 David Drolet * and Andrea Locke 1Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3 Canada 2Current address: Fisheries and Oceans Canada, Institut Maurice-Lamontagne, 850 route de la Mer, Mont-Joli, Québec, G5H 3Z4 Canada 3Department of Fisheries and Oceans Canada, Gulf Fisheries Centre, P.O. Box 5030, Moncton, New Brunswick, E1C 9B6 Canada E-mail: [email protected] (DD), [email protected] (AL) *Corresponding author Received: 11 February 2015 / Accepted: 23 September 2015 / Published online: 8 December 2015 Handling editor: Charles W. Martin Abstract Propagule pressure is emerging as the most consistent predictor of establishment in non-indigenous species. Increasing propagule size (the number of individuals arriving in a novel environment at one time) is thought to increase probability of establishment by counteracting demographic stochasticity and Allee effects. Increasing propagule number (the number of introduction events) is thought to increase probability of establishment by counteracting environmental stochasticity. However, the relative importance of these effects and the conditions under which one effect may become predominant is largely unexplored. We first used stochastic population simulations, with a constant number of immigrants distributed over varying numbers of introduction events, to determine the relative importance of propagule size and number on the probability of establishment.
    [Show full text]
  • Effects of Propagule Settlement Density and Adult Canopy on Survival of Recruits of Sargassum Spp. (Sargassaceae: Phaeophyta)
    MARINE ECOLOGY PROGRESS SERIES Vol. 103: 129-140, 1994 Published January 6 Mar. Ecol. Prog. Ser. Effects of propagule settlement density and adult canopy on survival of recruits of Sargassum spp. (Sargassaceae: Phaeophyta) Gary A. Kendrick* Department of Botany, University of Western Australia. Nedlands, Western Australia 6009, Australia ABSTRACT The effects of increased densities of settled propagules and the presence of adults on sur- vlval of recruits were lnvest~gatedto determine whether patterns of propagule settlement would pel- slst and be expressed as distribution of recruits for Sargassum spln~lllgeru~nS d~stlchun~and S poda- canthum in a subtidal mixed specles bed at Rottnest Island, Western Australia The effect of highei densities of settled propagules (recruit-recruit lnteractions) was studied uslng l~mestonesettlement plates seeded with known densities of propagules Density-dependent n~ortal~tyoccurred at settlement densities < 105 propagules m A large component of recruit mortality was density independent (57 "/;> of total mortality) Vanabllity in recruit survival at any one settlement density was also great Growth of recruits was negatively density dependent Two distinct sizes of recru~tswere observed (< 10 and > 10 mm in height) The effect of adult canopy (recruit-adult interactions) on recruit sur\ilval was stud- ied using a cleanng expenment where adult thalli were removed from 4 m2areas For the flrst 6 mo the presence of adults had llttle effect on recruit survival Aftei 6 mo, the presence of adults leduced recruit
    [Show full text]
  • Assessing the Relationship Between Propagule Pressure and Invasion Risk in Ballast Water
    ASSESSING THE RELATIONSHIP BETWEEN PROPAGULE PRESSURE AND INVASION RISK IN BALLAST WATER Committee on Assessing Numeric Limits for Living Organisms in Ballast Water Water Science and Technology Board Division on Earth and Life Studies THE NATIONAL ACADEMIES PRESS Washington, D.C. www.nap.edu PREPUBLICATION COPY THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the panel responsible for the report were chosen for their special competences and with regard for appropriate balance. Support for this study was provided by the EPA under contract no. EP-C-09-003, TO#11. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project. International Standard Book Number X-XXX-XXXXX-X Library of Congress Catalog Card Number XX-XXXXX Additional copies of this report are available from the National Academies Press, 500 5th Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu. Copyright 2011 by the National Academy of Sciences. All rights reserved. Printed in the United States of America. PREPUBLICATION COPY The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare.
    [Show full text]
  • Arbuscular Mycorrhizal Propagule Densities Respond Rapidly to Ponderosa Pine Restoration Treatments
    Journal of Applied Blackwell Science, Ltd Ecology 2003 Arbuscular mycorrhizal propagule densities respond 40, 101–110 rapidly to ponderosa pine restoration treatments JULIE E. KORB*†, NANCY C. JOHNSON‡ and W. W. COVINGTON* *Ecological Restoration Institute, College of Ecosystem Science and Management, Northern Arizona University, Flagstaff, AZ 86011, USA; †Biology Department, Fort Lewis College, Durango, CO 81301, USA; and ‡Environmental and Biological Sciences and the Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011, USA Summary 1. Mycorrhizae form a critical link between above-ground plants and the soil system by influencing plant nutrition, nutrient cycling and soil structure. Understanding how mycorrhizae respond to disturbances may lead to important advances in interpreting above-ground plant recovery. 2. The inoculum potential for arbuscular mycorrhizae (AM) and ectomycorrhizal (EM) fungi was investigated in thinned-only, thinned and prescribed burned (both restoration treatments) and unthinned and unburned control stands in northern Arizona ponderosa pine forests. The relationships between mycorrhizal fungal propagule densities and plant community and soil properties were quantified. 3. The relative amount of infective propagules of AM fungi was significantly higher in samples collected from both restoration treatments than their paired controls (unthinned and unburned stands). In contrast, the same restoration treatments had no significant effect on the relative amount of infective propagules of EM fungi. 4. The relative amount of infective propagules of AM fungi was significantly positively correlated with graminoid cover and herbaceous understorey species richness and negatively correlated with overstorey tree canopy cover and litter cover. 5. Synthesis and applications. These results indicate that population densities of AM fungi can rapidly increase following restoration treatments in northern Arizona pon- derosa pine forests.
    [Show full text]
  • Running Head 'Biology of Mangroves'
    BIOLOGY OF MANGROVES AND MANGROVE ECOSYSTEMS 1 Biology of Mangroves and Mangrove Ecosystems ADVANCES IN MARINE BIOLOGY VOL 40: 81-251 (2001) K. Kathiresan1 and B.L. Bingham2 1Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai 608 502, India 2Huxley College of Environmental Studies, Western Washington University, Bellingham, WA 98225, USA e-mail [email protected] (correponding author) 1. Introduction.............................................................................................. 4 1.1. Preface........................................................................................ 4 1.2. Definition ................................................................................... 5 1.3. Global distribution ..................................................................... 5 2. History and Evolution ............................................................................. 10 2.1. Historical background ................................................................ 10 2.2. Evolution.................................................................................... 11 3. Biology of mangroves 3.1. Taxonomy and genetics.............................................................. 12 3.2. Anatomy..................................................................................... 15 3.3. Physiology ................................................................................. 18 3.4. Biochemistry ............................................................................. 20 3.5. Pollination
    [Show full text]
  • Dispersal Modes of Free-Living, Aquatic Nematodes
    Hydrobiologia (2020) 847:3519–3547 https://doi.org/10.1007/s10750-020-04373-0 (0123456789().,-volV)( 0123456789().,-volV) REVIEW PAPER The ability to get everywhere: dispersal modes of free-living, aquatic nematodes Christoph Ptatscheck . Walter Traunspurger Received: 30 January 2020 / Revised: 30 July 2020 / Accepted: 1 August 2020 / Published online: 11 August 2020 Ó The Author(s) 2020 Abstract Nematodes colonize almost all aquatic parthenogenetic reproduction, nematodes are effective habitats worldwide. Despite their small size, restricted pioneers with the ability to (re)colonize new or locomotion and lack of pelagic larvae, they can reach disturbed habitats or rebalance already existing even isolated habitats within a short time. In this communities. review, we examine the underlying dispersal modes, considering their active movement in substrates and Keywords Meiofauna paradox Á Rafting Á water, their drift by water and wind, rafting, zoochory Zoochory Á Drifting Á Wind dispersal Á Locomotion as well as human-mediated vectors. These modes are limited by morphology and habitat structure, ecolog- ical factors and especially by hydrodynamics. Active dispersal is effective over short distances, but with Introduction increasing water-flow velocity, passive dispersal modes, which enable long-range transfer, become Nematodes are the most abundant metazoans in the important. In fact, the transport of nematodes over biosphere and colonize nearly all aquatic and semi- thousands of kilometers via ship water tanks and by aquatic habitats worldwide. They can be found in hitchhiking on sea turtles has been documented. permanent lotic and lentic surface waters, such as Overland dispersal vectors include wind and birds lakes and streams, and in the seabed.
    [Show full text]
  • Propagule Dispersal Determines Mangrove Zonation at Intertidal and Estuarine Scales
    Article Propagule Dispersal Determines Mangrove Zonation at Intertidal and Estuarine Scales Wenqing Wang, Xiaofei Li and Mao Wang * Key Laboratory of the Coastal and Wetland Ecosystems, Ministry of Education, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China; [email protected] (W.W.); [email protected] (X.L.) * Correspondence: [email protected]; Tel.: +86-136-6603-7893 Received: 1 February 2019; Accepted: 7 March 2019; Published: 10 March 2019 Abstract: Propagule dispersal has generally been recognized as a vital factor affecting the spatial structure of tropical forest plants. However, available research shows that this hypothesis does not apply to mangrove species the propagules of which are dispersed by water. Due to the lack of comprehensive and quantitative information as well as the high spatio-temporal heterogeneity of the mangrove environment, the exact factors affecting the spatial structure of mangrove forests are poorly understood. To assess this, we selected a mangrove estuary with high mangrove species richness that experiences great changes in water salinity. After investigating the zonation of mature mangrove individuals across tides and the estuary, we measured the size and initial specific gravity of the propagules and then selected the eight most common species from which to observe the changes in specific gravity, buoyancy, and root initiation during dispersal at different sites with different water salinity regimes. The relationships among distribution patterns, propagule establishment, and dispersal behavior were investigated. We found that mangrove propagule dispersal is not a passively buoyant process controlled by water currents. During dispersal, mangrove propagules can actively adjust their specific gravity and root initiation.
    [Show full text]
  • Factors Limiting the Intertidal Distribution of the Mangrove
    Oecologia (2003) 135:110-121 DOI 10.1007/s00442-002-1167-2 James A. Allen * Ken W. Krauss * Robert D. Hauff Factorslimiting the intertidaldistribution of the mangrovespecies Xylocarpusgranatum Received: 28 October 2002 / Accepted: 27 November 2002 / Published online: 1 February2003 ? Springer-Verlag2003 Abstract The tree species Xylocarpus granatum is com- important, especially relative to a potential contribution to monly described as occurring in the upper intertidal zone secondary stress mortality. Other factors may ultimately of mangrove forests, but mature trees are occasionally prove to be more critical, such as physiological effects of found at lower elevations. In the Utwe River basin, on the salinity on seed germination, effects of tides on seed Pacific island of Kosrae, we investigated the relative dispersal and rooting, or differential herbivory on importance of several biotic and abiotic factors that may seedlings. control the intertidal distribution of X. granatum. Factors we evaluated included differential seed predation across Keywords Kosrae Federated States of Micronesia the lower, mid, and upper intertidal zones and seedling Seed predation. Salinity tolerance Flood tolerance responses to salinity, tidal flooding, and shade. Seed predation was 22.4% over the first 34 days and varied little among zones or in gaps versus under the forest Introduction canopy. By day 161, there were still no differences in seed mortality, but a significant difference was found in Patterns of mangrove tree species zonation have been the seedling establishment, with much greater establishment subject of scientific interest for many decades (Watson in the upper intertidal plots. X. granatum seedlings in a 1928; Davis 1940; Egler 1950; Macnae 1968; Chapman greenhouse experiment exhibited greater growth in 1976).
    [Show full text]
  • Vegetative Propagules
    Glime, J. M. 2017. Adaptive Strategies: Vegetative Propagules. Chapt. 4-10. In: Glime, J. M. Bryophyte Ecology. Volume 1. 4-10-1 Physiological Ecology. Ebook sponsored by Michigan Technological University and the International Association of Bryologists. Last updated 24 April 2021 and available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>. CHAPTER 4-10 ADAPTIVE STRATEGIES: VEGETATIVE PROPAGULES TABLE OF CONTENTS Vegetative Reproduction ................................................................................................................................... 4-10-2 Adaptations ....................................................................................................................................................... 4-10-8 Fragmentation ................................................................................................................................................... 4-10-8 Leaves and Stems ..................................................................................................................................... 4-10-10 Regenerants .............................................................................................................................................. 4-10-14 Protonemata ............................................................................................................................................. 4-10-14 Perianths ..................................................................................................................................................
    [Show full text]
  • Marine Ecology Progress Series 524:95
    Vol. 524: 95–106, 2015 MARINE ECOLOGY PROGRESS SERIES Published March 30 doi: 10.3354/meps11206 Mar Ecol Prog Ser Impact of landscape structure on propagule dispersal in mangrove forests T. Van der Stocken1,2,*, D. J. R. De Ryck1,2, B. Vanschoenwinkel1, E. Deboelpaep1, T. J. Bouma3, F. Dahdouh-Guebas1,2, N. Koedam1 1Laboratory of Plant Biology and Nature Management, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium 2Laboratory of Systems Ecology and Resource Management, Université Libre de Bruxelles (ULB), Av. F.D. Roosevelt 50, CPI 264/1, 1050 Brussels, Belgium 3Department of Spatial Ecology, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 140, 4400 AC Yerseke, The Netherlands ABSTRACT: Although many riparian and semi-aquatic plant species disperse via water currents, little is known about how this process interacts with the landscape matrix. In mangroves, the dense aerial root network could act as a strong dispersal barrier for the morphologically diverse propag- ules found in these trees. In this study, we combined field and laboratory experiments to test the effect of root density, propagule morphology and hydrodynamic variables on retention rates and trajectories of the propagules of 4 common species. Overall, flume experiments showed that larger propagules were more frequently retained than smaller ones. For the larger propa gules, retention rates increased with increasing obstacle density in the landscape matrix. In elongated propagules, intraspecific variation was linked to floating orientation. Experimental wave action and increased water flow velocity reduced retention. Dispersal in the field was constrained by major tidal cur- rents and experiments confirmed less retention of smaller propagules, which moved farther than larger ones.
    [Show full text]
  • And Long-Term Effects of Disturbance and Propagule Pressure on a Biological Invasion
    Journal of Ecology 2008, 96, 68–77 doi: 10.1111/j.1365-2745.2007.01319.x ShorBlackwell Publishing Ltd t- and long-term effects of disturbance and propagule pressure on a biological invasion Kevin H. Britton-Simmons* and Karen C. Abbott† Department of Ecology and Evolution, The University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA Summary 1. Invading species typically need to overcome multiple limiting factors simultaneously in order to become established, and understanding how such factors interact to regulate the invasion process remains a major challenge in ecology. 2. We used the invasion of marine algal communities by the seaweed Sargassum muticum as a study system to experimentally investigate the independent and interactive effects of disturbance and propagule pressure in the short term. Based on our experimental results, we parameterized an integrodifference equation model, which we used to examine how disturbances created by different benthic herbivores influence the longer term invasion success of S. muticum. 3. Our experimental results demonstrate that in this system neither disturbance nor propagule input alone was sufficient to maximize invasion success. Rather, the interaction between these processes was critical for understanding how the S. muticum invasion is regulated in the short term. 4. The model showed that both the size and spatial arrangement of herbivore disturbances had a major impact on how disturbance facilitated the invasion, by jointly determining how much space-limitation was alleviated and how readily disturbed areas could be reached by dispersing propagules. 5. Synthesis. Both the short-term experiment and the long-term model show that S.
    [Show full text]
  • Risk Analysis for Phytophthora Ramorum, a Newly Recognised Pathogen Threat to Europe and the Cause of Sudden Oak Death in the USA (Acronym - RAPRA) Claire Sansford, A
    Risk analysis for Phytophthora ramorum, a newly recognised pathogen threat to Europe and the cause of Sudden Oak Death in the USA (Acronym - RAPRA) Claire Sansford, A. J. Inman, R. Baker, Susan Frankel, J. de Gruyter, Claude Husson, Hella Kehlenbeck, G. Kessel, E. Moralejo, M. Steeghs, et al. To cite this version: Claire Sansford, A. J. Inman, R. Baker, Susan Frankel, J. de Gruyter, et al.. Risk analysis for Phytophthora ramorum, a newly recognised pathogen threat to Europe and the cause of Sudden Oak Death in the USA (Acronym - RAPRA). [Contract] auto-saisine. 2009, 310 p. hal-01245979 HAL Id: hal-01245979 https://hal.archives-ouvertes.fr/hal-01245979 Submitted on 17 Dec 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. EU Sixth Framework Project Contract Number 502672 Risk Analysis of Phytophthora ramorum , a Newly Recognised Pathogen Threat to Europe and the Cause of Sudden Oak Death in the USA (Acronym – RAPRA) PRIORITY 8.1.B.1 POLICY-ORIENTED RESEARCH SPECIFIC TARGETTED RESEARCH PROJECT – RAPRA Deliverable Report D28 Report on the risk of entry, establishment, spread and socio-economic loss and environmental impact and the appropriate level of management for Phytophthora ramorum for the EU Date of Report: 26 th February 2009 (Previous versions: 21 st November 2008; 23 rd January 2009) CONTENTS Page no.
    [Show full text]