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Japanese Oak Wilt
Japanese oak wilt (also called mortality of oak trees in Japan) is a fungal disease caused by ''Raffaelea quercivora'' fungus affecting by oak trees. In 1998, Japanese plant pathologists group was isolation, inoculation and reisolation the dead tree.Ito S., Kubono T., Sahasi N., Yamada T.(199Associated fungi with the mass mortality of oak trees ''Journal of the Japanese Forestry Society 80(3), 170-175.'' It is the first disease known that ''Raffaela'' fungus cause plant disease. Symptoms The first obvious symptom was that the leaves wilted, and many small holes appeared on the trunk. The leaves turned to red and died back quickly (1 or 2 weeks), and finally the tree died. If you cut the dead tree, you would discover the xylem had been discolored to brown. Mechanism The oak trees react plugging their xylem with gum and tyloses for blocking the fungus spreading.{{cite journal, url=http://ci.nii.ac.jp/naid/110002830776/en, author1=Kuroda, K. , author2=Yamada, T. , year=1996, title= D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raffaelea Quercivora
''Raffaelea quercivora'' is a species of fungus in the family Ophiostomataceae The Ophiostomataceae are a family of fungi in the Ascomycota, class Sordariomycetes. The family was circumscribed by J.A. Nannfeldt in 1932. Species in the family have a widespread distribution, and are typically found in temperate regions .... It causes Japanese oak wilt disease, and is spread by the ambrosia beetle ('' Platypus quercivorus''). It has small obovoid to pyriform sympodioconidia and slender, long conidiophores. The fungus has been isolated from the body surfaces and mycangia of the beetle. References Further reading * * * * * External links * Fungi described in 2002 Ophiostomatales {{Sordariomycetes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from the Ancient Greek word (''xylon''), meaning "wood"; the best-known xylem tissue is wood, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called ''vessels''. Xylem also contains two other type of cells: parenchyma and fibers. Xylem can be found: * in vascular bundles, present in non-woody plants and non-woody parts of woody plants * in secondary xylem, laid down by a meristem called the vascular cambium in woody plants * as part of a stelar arrangement n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tylose
Tyloses are outgrowths/extragrouth on parenchyma cells of xylem vessels of secondary heartwood. When the plant is stressed by drought or infection, tyloses will fall from the sides of the cells and "dam" up the vascular tissue to prevent further damage to the plant. Tyloses can aid in the process of making sapwood into heartwood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin tha ... in some hardwood trees, especially in trees with larger vessels. These blockages can be used in addition to gum plugs as soon as vessels become filled with air bubbles, and they help to form a stronger heartwood by slowing the progress of rot. References Plant anatomy {{botany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch Elm Disease
Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America, Europe, and New Zealand. In these regions it has devastated native populations of elms that did not have resistance to the disease. The name "Dutch elm disease" refers to its identification in 1921 and later in the Netherlands by Dutch phytopathologists Marie Beatrice Schol-Schwarz, Bea Schwarz and Christine Buisman, who both worked with professor Johanna Westerdijk. The disease affects species in the genera ''Ulmus'' and ''Zelkova''; therefore it is not specific to the Ulmus × hollandica, Dutch elm hybrid. Overview Dutch elm disease (DED) is caused by ascomycete microfungi. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bark Beetle
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus ''Scolytus'', namely the European elm bark beetle ''S. multistriatus'' and the large elm bark beetle ''S. scolytus'', which like the American elm bark beetle ''Hylurgopinus rufipes'', transmit Dutch elm disease fungi (''Ophiostoma''). The mountain pine beetle ''Dendroctonus ponderosae'', southern pine beetle ''Dendroctonus frontalis'', and their near relatives are major pests of conifer forests in North America. A similarly aggressive spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambrosia Beetle
Ambrosia beetles are beetles of the weevil subfamilies Scolytinae and Platypodinae ( Coleoptera, Curculionidae), which live in nutritional symbiosis with ambrosia fungi. The beetles excavate tunnels in dead, stressed, and healthy trees in which they cultivate fungal gardens, their sole source of nutrition. After landing on a suitable tree, an ambrosia beetle excavates a tunnel in which it releases spores of its fungal symbiont. The fungus penetrates the plant's xylem tissue, extracts nutrients from it, and concentrates the nutrients on and near the surface of the beetle gallery. Ambrosia fungi are typically poor wood degraders, and instead utilize less demanding nutrients. The majority of ambrosia beetles colonize xylem (sapwood and/or heartwood) of recently dead trees, but some attack stressed trees that are still alive, and a few species attack healthy trees.Hulcr, J. and Stelinski, L.L., 2017. The ambrosia symbiosis: From evolutionary ecology to practical management. Annu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurel Wilt
Laurel wilt, also called laurel wilt disease, is a vascular disease that is caused by the fungus ''Raffaelea lauricola'', which is transmitted by the invasive redbay ambrosia beetle, ''Xyleborus glabratus''. The disease affects and kills members of the laurel family. The avocado is perhaps the most commercially valuable plant affected by laurel wilt. Symptoms Symptoms of laurel wilt include wilted stems and leaves and dark streaking in the wood. Laurel wilt can spread in at least two ways: one is via the beetle's natural reproduction and migration. A second way is through the sale and transport of beetle-infested wood, a result of redbay's use as firewood and for outdoor grilling. Life cycle ''R. lauricola'' is symbiotic with ''X. glabratus''. It reproduces clonally and is vertically transmitted originally evolving from a sexual population of mutualists. This combination of traits and ancestral traits is common, however Dreaden et al 2019 finds ''R. lauricola'' to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pine Wilt
''Bursaphelenchus xylophilus'', commonly known as pine wood nematode or pine wilt nematode (PWN), is a species of nematode that infects trees in the ''Pinus'' genus of coniferous trees and causes the disease pine wilt.''Bursaphelenchus xylophilus''. Nemaplex. UC Davis. While native to North America, it spread in the early 20th century to and in the latter half of the century to other areas of , including , |
Oak Wilt
Oak wilt is a fungal disease caused by the organism ''Bretziella fagacearum'' that threatens ''Quercus'' spp. The disease is limited to the Midwestern and Eastern United States; first described in the 1940s in the Upper Mississippi River Valley. The pathogen penetrates xylem tissue, preventing water transport and causing disease symptoms. Symptoms generally consist of leaf discoloration, wilt, defoliation, and death. The disease is dispersed by insect vectors and to adjacent trees through underground root networks. However, human spread is the most consequential dispersal method. Moving firewood long distances can potentially transport diseases and invasive species. Disease Oak wilt is a devastating exotic disease, killing some trees rapidly in a single season. Oak wilt is an important disease in urban areas where trees are highly valued. The disease reduces property values because of the loss of trees and is economically costly to the property owner since they or the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudden Oak Death
James Green aka "Sudden" is a fictional character created by an English author Oliver Strange in the early 1930s as the hero of a series, originally published by George Newnes Books Ltd, set in the American Wild West era. Oliver Strange died in 1952, and the series was revived by Frederick H. Christian in the 1960s. Christian classified the books as "Piccadilly westerns", that is books written by English authors, simply drawing on the conventions the genre, with no first hand experience of America. The Sudden books are among the earliest and best-loved of the type. Sudden is portrayed as an intrepid and accurate gunfighter in search of two men who cheated his foster father. James Green earns the nickname "Sudden" because of his lightning speed with a gun. Sudden is portrayed as a stereotypical gunfighter: an intelligent and resourceful drifting cowboy who is respectful of the law, unwilling to use a gun unless absolutely necessary, humanitarian, brave, strong, and fair. The firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
