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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= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raffaelea Quercivora
''Raffaelea quercivora'' is a species of fungus in the family Ophiostomataceae. 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 The term mycangium (pl., mycangia) is used in biology for special structures on the body of an animal that are adapted for the transport of symbiotic fungi (usually in spore form). This is seen in many xylophagous insects (e.g. horntails and bark ... of the beetle. References Further reading * * * * * External links * Fungi described in 2002 Ophiostomatales Fungus species {{Sordariomycetes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue (biology), tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts of the plants such as stems and leaves, but it also transports plant nutrition, nutrients. The word ''xylem'' is derived from the Ancient Greek word (), meaning "wood"; the best-known wood organism is plants, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cell (biology), 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''. Wood also contains two other type of cells: Ground tissue#Parenchyma, parenchyma and ground tissue#Fibres, fibers. Xylem can be found: * in vascular bundles, present in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tylose
In woody plants, a tylosis (plural: tyloses) is a bladder-like distension of a parenchyma cell into the lumen of adjacent vessels. The term tylosis summarises the physiological process and the resulting occlusion in the xylem of woody plants as response to injury or as protection from decay in heartwood. It is a key process in wall one of the compartmentalization of decay in trees (CODIT) and other woody plants. Anatomy Observed in section under a microscope, tyloses appear as balloon-like protrusions emanating from axial paratracheal parenchyma cells into xylem vessels through pits linking the two. In some types, there may be a distinct barrier between the tyloses emanating from the pits into the vessels, while they may be barely distinguishable in other cases. Tyloses Tyloses are outgrowths 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 vascula ... [...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 aggres ... [...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 or stressed trees into which they introduce fungal gardens, their sole source of nutrition. After landing on a suitable tree, an ambrosia beetle excavates a tunnel in which it releases 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-decay fungus, wood degraders, and instead utilize less demanding nutrients. Symbiotic fungi produce and detoxify ethanol, which is an attractant for ambrosia beetles and likely prevents growth of Antagonism (phytopathology), antagonistic pathogens and selects for other beneficial symbionts. The majority of ambrosia beetles colonize xylem (sapwood and/or heartwood) of recently dead trees, bu ... [...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 b ... [...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 eastern half of the United States, Central Texas, and Southern Ontario. 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 ... [...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 Gunfighters, also called gunslingers () or in the late 19th and early 20th century gunmen, were individuals in the American Old West who gained a reputation of being dangerous with a gun and participated in shootouts. Today, the term "gunslin ... in search of two men who cheated his foster father. James Green earns the nickname "Sudden" because of his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
