Elm Disease Research Articles

Dutch elm disease

Dutch elm disease

Dutch elm disease

The Dutch elm disease (DED) pathogen infects the vascular tissues of elms and disrupts their water t…

ALIEN INVASIVE PATHOGENS: THE MAJOR THREAT TO OUR FOREST ECOSYSTEMS IN A TIME OF RAPID CLIMATE CHANGE

Forest ecosystems face unprecedented challenges from the rising rate of influx of alien invasive pests and pathogens resulting from increased global trade. Moreover, climate change predictions suggest that many additional alien pests and pathogens may become problems in forests as temperatures increase and rainfall patterns change. Recent indications of the potential for pathogens to transfer between hosts and the inter-specific hybridisation possible between related pathogens increase concerns over the possibility of escalations in damage in the future. Why are these organisms such a threat? Using examples drawn from wide-scale environmental damage caused to tree populations and forest ecosystems in Europe and elsewhere in the world, in this talk, we will illustrate the potential of alien pathogens to reduce biodiversity, alter ecosystems beyond recognition and impact on human requirements of forests. Classic examples of devastation by alien invasive pathogens affecting trees include Dutch elm disease, caused by Ophiostoma novo-ulmi, Jarrah dieback caused by Phytophthora cinnamomi, canker stain disease of Platanus caused by Ceratocystis platani, and white pine blister rust arising from accidental trans-Atlantic transfer of Cronartium ribicola. Many other examples exist in Europe and elsewhere in the world. Each of these pathogens still causes severe ecosystem damage in areas of introduction. Recent findings obtained from the application of state-of-the-art tools in molecular biology are reshaping our knowledge of alien invasive pathogens. The advent of these molecular biological techniques has greatly enhanced our ability to analyse aspects related to the biology, taxonomy, hidden biodiversity and temporal and spatial structuring of genetic diversity in organisms. Molecular diagnostic assays have resulted in improved detection methods for pests and pathogens based on molecular profiles, that are essential for accurate and rapid detection and enhanced understanding of the pathways of dispersal locally and internationally. This information greatly increases the reliability of pest risk assessment procedures and the development of phytosanitary measures aimed at eradicating, containing or managing these pests. The possibility of regulating the ‘plants for planting’ pathway, one of the major routes through which alien invasive problems are now entering and being dispersed in Europe, will be discussed.

Noble Hardwoods. EUFORGEN Genetic Conservation Network

The EUFORGEN network on noble hardwoods was established in 1996 and formulated at its first meeting the objective as follows: Identification of minimum gene conservation activities in the long term from a European perspective. A more specific formulation of the objective is: To safeguard the evolutionary potential of a species. Another objective valid for wild relatives of domesticated fruit tree species is to preserve their present genetic constitution. Since the genetic knowledge is scanty for most noble hardwoods the gene conservation methods have to a large extent be based on educated guesses about genetic differentiation among populations as well as the dynamics of the populations. For most commonly occurring species the in situ version of the Multiple Population Breeding System (MPBS) is suggested. MPBS means that the gene resource population is split into 20-30 subpopulations, each with an effective population size of at least 50 trees. Species with wide pollen dispersal will have the lower number of populations whereas species with limited pollen dispersal require more populations. Gene conservation in low hedges of elms is a method that prevents the attacks of the vector of the serious Dutch elm disease. For rarely occurring species establishment of clone archives to increase the effective population size is suggested. In most cases there will be no funding for such an expensive gene conservation. For these cases delivery of seedlings free of charge is an alternative. Many of the rarely occurring species are secondary species in an ecosystem and as such suffer from competition from climax species. Alleviation of this competition by thinning of the competing species is useful. The recommendations by the network should be regarded as a minimum from a European perspective and each country can complement with more gene resource populations.

Dutch elm disease

Dutch elm disease

Die mogliche Verbreitung des »UImensterbens« durch Wurzel-verwachsungen bei Ulmus carpinifolia Gled.

Possible spread of »elm disease« in Ulmus carpinifolia Gled. through root grafts. In a stand of elms (Ulmus carpinifolia Gled.), nearly all the trees were joined in groups of various sizes by “connecting roots”.

PHOTOGRAPHY USED IN BATTLE WITH ELM DISEASE

School Science and MathematicsVolume 73, Issue 5 p. 397-397 PHOTOGRAPHY USED IN BATTLE WITH ELM DISEASE First published: May 1973 https://doi.org/10.1111/j.1949-8594.1973.tb09063.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume73, Issue5May 1973Pages 397-397 RelatedInformation

Chemical Analysis of the Cell Wall of Ceratocystis Ulmi

(1964). Chemical Analysis of the Cell Wall of Ceratocystis Ulmi. Mycologia: Vol. 56, No. 5, pp. 738-744.

Elm Disease

ELM disease has been a serious pest in Britain during the last score of years. The Forestry Commission has issued Leaflet No. 19 (London : H.M. Stationery Office, 1947), which is an up-to-date account of what is known at present about this disease, the life-histories of the associated bark beetles, and control measures.

Studies in the genus Ustulina with special reference to Parasitism : V. A disease of elm ( Ulmus campestris sm.) caused by Ustulina

1. A diseased elm was investigated with the object of showing that Ustulina was responsible for the disease, and of continuing an attempt to establish the status of this fungus as a pathogen of timber trees in temperate regions. 2. The causal organism was isolated and found to be solely Ustulina . This was confirmed by reinfection and subsequent reisolation. 3. The stem and roots of the tree were sectioned and examined to determine the nature and extent of the disease. 4. Microscopic examination of the wood showed that the type of disintegration of the wood elements compared closely with that of the lime and that the final result of decay was almost identical in both. 5. The distribution of the mycelium and hyphal penetration is briefly commented on. 6. This elm disease is compared with the lime disease and it is concluded that Ustulina vulgaris is capable of causing a white rot of elm.

"Action Now" Imperative, as Elm Disease Menace Grows

"Action Now" Imperative, as Elm Disease Menace Grows