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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 , |
Wilt Disease
A wilt disease is any number of diseases that affect the vascular system of plants. Attacks by fungi, bacteria, and nematodes can cause rapid killing of plants, large tree branches or even entire trees. Wilt diseases in woody plants tend to fall into two major categories, those that start with the branches and those that start with the roots. Those that start with the branches most often start with pathogens that feed on the leaves or bark, those that start with the roots start with wounding or direct entry by the pathogen into the roots, some are spread from one plant to another by way of root grafts. Pathogens that cause wilting diseases invade the vascular vessels and cause the xylem to fail to transport water to the foliage, thus causing wilting of stems and leaves. Wilt diseases Wilt diseases include: Bacterial wilt of cucurbits Bacterial wilt of cucurbits is cause by the bacteria ''Erwinia tracheiphila'', it affects cucumber, squash, muskmelon, pumpkin, gourds; certain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spicule (nematode)
In nematodes, spicules, also known as copulatory spicules, are needle-like mating structures found only in males. Male nematodes may have one or two spicules which serve to open the vulva of females and facilitate the transmission of sperm, although sperm is not transferred directly by or through the spicules.Chitwood, B. G. & Chitwood, M. B. (1950). Introduction to Nematology (Vol. 1). Baltimore: Monumental Printing Co. (Function of spicule: pages 123-124) The gubernaculum The paired gubernacula (from Ancient Greek κυβερνάω = pilot, steer) also called the caudal genital ligament, are embryonic structures which begin as undifferentiated mesenchyme attaching to the caudal end of the gonads (testes in male ... is another organ of the nematode male copulatory system which guides the spicules during copulation. References Nematode anatomy Animal male reproductive system {{nematode-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic of Korea) comprising its southern half. Korea consists of the Korean Peninsula, Jeju Island, and several minor islands near the peninsula. The peninsula is bordered by China to the northwest and Russia to the northeast. It is separated from Japan to the east by the Korea Strait and the Sea of Japan (East Sea). During the first half of the 1st millennium, Korea was divided between three states, Goguryeo, Baekje, and Silla, together known as the Three Kingdoms of Korea. In the second half of the 1st millennium, Silla defeated and conquered Baekje and Goguryeo, leading to the "Unified Silla" period. Meanwhile, Balhae formed in the north, superseding former Goguryeo. Unified Silla eventually collapsed into three separate states due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chamaecyparis Obtusa
''Chamaecyparis obtusa'' (Japanese cypress, hinoki cypress or hinoki; ja, 檜 or , ) is a species of cypress native to central Japan in East Asia, and widely cultivated in the temperate northern hemisphere for its high-quality timber and ornamental qualities, with many cultivars commercially available. Description It is a slow-growing tree which may reach tall with a trunk up to in diameter. The bark is dark red-brown. The leaves are scale-like, long, blunt tipped (obtuse), green above, and green below with a white stomatal band at the base of each scale-leaf. The cones are globose, in diameter, with 8–12 scales arranged in opposite pairs. Related species The plant is widespread in Japan. The related '' Chamaecyparis pisifera'' (sawara cypress) can be readily distinguished in its having pointed tips to the leaves and smaller cones. A similar cypress found on Taiwan is treated by different botanists as either a variety of this species (as ''Chamaecyparis obtusa'' va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptomeria
''Cryptomeria'' (literally "hidden parts") is a monotypic genus of conifer in the cypress family Cupressaceae, formerly belonging to the family Taxodiaceae. It includes only one species, ''Cryptomeria japonica'' ( syn. ''Cupressus japonica'' L.f.). It used to be considered by some to be endemic to Japan (see remark below under 'Endemism'), where it is known as . The tree is called Japanese cedar or Japanese redwood in English. It has been extensively introduced and cultivated for wood production on the Azores. Description ''Cryptomeria'' is a very large evergreen tree, reaching up to tall and trunk diameter, with red-brown bark which peels in vertical strips. The leaves are arranged spirally, needle-like, long; and the seed cones globular, diameter with about 20–40 scales. It is superficially similar to the related giant sequoia (''Sequoiadendron giganteum''), from which it can be differentiated by the longer leaves (under in the giant sequoia) and smaller cones ( in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Taeda
''Pinus taeda'', commonly known as loblolly pine, is one of several pines native to the Southeastern United States, from East Texas to Florida, and north to southern New Jersey. The wood industry classifies the species as a southern yellow pine. U.S. Forest Service surveys found that loblolly pine is the second-most common species of tree in the United States, after red maple. For its timber, the pine species is regarded as the most commercially important tree in the Southeastern U.S. The common name loblolly is given because the pine species is found mostly in lowlands and swampy areas. Loblolly pine is the first among over 100 species of ''Pinus'' to have its complete genome sequenced. As of March 2014, it was the organism having the largest sequenced genome size. Its genome, with 22 billion base pairs, is seven times larger than that of humans. As of 2018, assembly of the axolotl genome (32Gb) displaced loblolly pine as the largest assembled genome. The loblolly pine was sel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jack Pine
Jack pine (''Pinus banksiana'') is an eastern North American pine. Its native range in Canada is east of the Rocky Mountains from the Mackenzie River in the Northwest Territories to Cape Breton Island in Nova Scotia, and the north-central and northeast of the United States from Minnesota to Maine, with the southernmost part of the range just into northwest Indiana and northwest Pennsylvania. It is also known as grey pine and scrub pine. In the far west of its range, ''Pinus banksiana'' hybridizes readily with the closely related lodgepole pine (''Pinus contorta''). The species epithet ''banksiana'' is after the English botanist Sir Joseph Banks. Description ''Pinus banksiana'' ranges from in height. Some jack pines are shrub-sized, due to poor growing conditions. They do not usually grow perfectly straight, resulting in an irregular shape similar to pitch pine (''Pinus rigida''). This pine often forms pure stands on sandy or rocky soil. It is fire-adapted to stand- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Densiflora
''Pinus densiflora'', also called the Japanese red pine, the Japanese pine, or Korean red pine, is a species of pine tree native to East Asia. Distribution and habitat ''P. densiflora'' has a home range that includes Japan, the Korean Peninsula, northeastern China (Heilongjiang, Jilin, Liaoning, Shandong) and the extreme southeast of Russia (in Siberia, southern Primorsky Krai). Description The leaves are needle-like, long, with two per fascicle. The cones are long. It is closely related to Scots pine, differing in the longer, slenderer leaves which are mid-green without the glaucous-blue tone of Scots pine. This pine has become a popular ornamental and has several cultivars, but in the winter it becomes yellowish. The height of this tree is . The plant prefers full sun on well-drained, slightly acidic soil. Cultivation In Japan it is known as and . It is widely cultivated in Japan both for timber production and as an ornamental tree, and plays an important part in the classic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyushu
is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surrounding islands. Kyushu has a land area of and a population of 14,311,224 in 2018. In the 8th-century Taihō Code reforms, Dazaifu was established as a special administrative term for the region. Geography The island is mountainous, and Japan's most active volcano, Mount Aso at , is on Kyushu. There are many other signs of tectonic activity, including numerous areas of hot springs. The most famous of these are in Beppu, on the east shore, and around Mt. Aso in central Kyushu. The island is separated from Honshu by the Kanmon Straits. Being the nearest island to the Asian continent, historically it is the gateway to Japan. The total area is which makes it the 37th largest island in the world. It's slightly larger than Taiwan island . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bordered by the state of Texas to the west, Arkansas to the north, Mississippi to the east, and the Gulf of Mexico to the south. A large part of its eastern boundary is demarcated by the Mississippi River. Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska and its boroughs). The state's capital is Baton Rouge, and its largest city is New Orleans, with a population of roughly 383,000 people. Some Louisiana urban environments have a multicultural, multilingual heritage, being so strongly influenced by a mixture of 18th century Louisiana French, Dominican Creole, Spanish, French Canadian, Acadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longleaf Pine
The longleaf pine (''Pinus palustris'') is a pine species native to the Southeastern United States, found along the coastal plain from East Texas to southern Virginia, extending into northern and central Florida. In this area it is also known as "yellow pine" or "long leaf yellow pine", although it is properly just one out of a number of species termed yellow pine. It reaches a height of and a diameter of . In the past, before extensive logging, they reportedly grew to with a diameter of . The tree is a cultural symbol of the Southern United States, being the official state tree of Alabama. Contrary to popular belief, this particular species of pine is not officially the state tree of North Carolina. Description The bark is thick, reddish-brown, and scaly. The leaves are dark green and needle-like, and occur in bundles of mainly three, sometimes two or four, especially in seedlings. They often are twisted and in length. A local race of ''P. palustris'' in a cove near Rockin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
