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Tachibana Orange
The tachibana orange (''Citrus tachibana,'' or ''Citrus reticulata tachibana'') is a variety of mandarin orange, a citrus fruit. They grow wild in the forests of Japan and are referred to in the poetry of the early Japanese and Ryukyu Islands kingdoms. and Supplement The Tanaka System assigns them their own species, while the Swingle System places them in the same species with other mandarin oranges. Genomic analysis has shown tachibana oranges to be a constellation of distinct natural F1 hybrids that cross the pure Ryukyu Island mandarin '' C. ryukyuensis'' with mainland Asian '' C. reticulata'' that was itself a hybrid of northern and southern subspecies, but also contained some prior Ryukyu mandarin introgression. They lack the pomelo introgression found in the closely-related domesticated mandarin oranges of mainland Asia, though they have a mainland-mandarin-derived transposable element insertion that causes them to reproduce asexually by apomixis, unlike their sexually-rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plantae
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the abilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus Ryukyuensis
''Citrus ryukyuensis'' is a newly characterized wild citrus species native to the Ryukyus and adjacent islands, most closely related to the mainland mandarin orange, ''C. reticulata''. As with other citrus, it is a member of the Rutaceae family. The Ryukyu and mainland species have diverged for more than 2 million years, and unlike the mainland mandarin, the Ryukyu mandarin reproduces sexually. Its hybridization with the mainland species has given rise to the unique mandarin hybrids of the islands. Discovery and characterization Previous genetic studies that characterized the mandarin oranges of the Asian mainland left unexplained the unusual genetic characteristics of those from Japan and nearby islands. A followup study designed at filling this gap in understanding produced an unexpected result, the identification of a pure wild species of mandarin, the hybridization of which with the mainland species has given rise to multiple distinct mandarin orange hybrid clusters. Because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Dispersal
Oceanic dispersal is a type of biological dispersal that occurs when terrestrial organisms transfer from one land mass to another by way of a sea crossing. Island hopping is the crossing of an ocean by a series of shorter journeys between islands, as opposed to a single journey directly to the destination. Often this occurs via large rafts of floating vegetation such as are sometimes seen floating down major rivers in the tropics and washing out to sea, occasionally with animals trapped on them. Dispersal via such a raft is sometimes referred to as a rafting event. Colonization of land masses by plants can also occur via long-distance oceanic dispersal of floating seeds. History Rafting has played an important role in the colonization of isolated land masses by mammals. Prominent examples include Madagascar, which has been isolated for ~120 million years ( Ma), and South America, which was isolated for much of the Cenozoic. Both land masses, for example, appear to have receiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation. Individual pulses of cold climate within an ice age are termed '' glacial periods'' (or, alternatively, ''glacials, glaciations, glacial stages, stadials, stades'', or colloquially, ''ice ages''), and intermittent warm periods within an ice age are called '' interglacials'' or ''interstadials''. In glaciology, ''ice age'' implies the presence of extensive ice sheets in both northern and southern hemispheres. By this definition, Earth is currently in an interglacial period—the Holocene. The amount of anthropogenic greenhouse gases emitted into Earth's oceans and atmosphere is predicted to prevent the next glacial period for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the two reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Bridge
In biogeography, a land bridge is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonize new lands. A land bridge can be created by marine regression, in which sea levels fall, exposing shallow, previously submerged sections of continental shelf; or when new land is created by plate tectonics; or occasionally when the sea floor rises due to post-glacial rebound after an ice age. Prominent examples * Adam's Bridge (also known as Rama Setu), connecting India and Sri Lanka * The Bassian Plain, which linked Australia and Tasmania * The Bering Land Bridge (aka Beringia), which intermittently connected Alaska (Northern America) with Siberia (North Asia) as sea levels rose and fell under the effect of ice ages * East Asia’s former unnamed landmass, During the last Ice Age, which ended approximately 15,000 years ago, Japanese Archipelago was connected to the main continent through several land bridges, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanling Mountains
The Nanling (), also known as the Wuling (), is a major mountain range in Southern China that separates the Pearl River Basin from the Yangtze Valley and serves as the dividing line between south and central subtropical zones. The main range of Nanling Mountains stretch west to east about from Guilin and Hezhou of the eastern Guangxi to Ganzhou of the southern Jiangxi, north to south about from Yongzhou and Chenzhou of the southern Hunan to Qingyuan and Shaoguan of the northern Guangdong; With its branches, the whole mountains run west to east . There are trough basins in the Nanling, the most of the western basins in Nanling Mountains are composed of limestone, where karst regions are located. the most of the eastern basins are made up of red sandstone, where are danxia landform areas. The Nanling are boundaries between the four provinces of Guangdong, Guangxi, Hunan and Jiangxi, and also the cultural boundaries, on the south of the mountains are Lingnan culture area.a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apomixis
In botany, apomixis is asexual reproduction without fertilization. Its etymology is Greek for "away from" + "mixing". This definition notably does not mention meiosis. Thus "normal asexual reproduction" of plants, such as propagation from cuttings or leaves, has never been considered to be apomixis, but replacement of the seed by a plantlet or replacement of the flower by bulbils were categorized as types of apomixis. Apomictically produced offspring are genetically identical to the parent plant. Some authors included all forms of asexual reproduction within apomixis, but that generalization of the term has since died out. In flowering plants, the term "apomixis" is commonly used in a restricted sense to mean agamospermy, i.e., clonal reproduction through seeds. Although agamospermy could theoretically occur in gymnosperms, it appears to be absent in that group. Apogamy is a related term that has had various meanings over time. In plants with independent gametophytes (notably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposable Element
A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transposition often results in duplication of the same genetic material. Barbara McClintock's discovery of them earned her a Nobel Prize in 1983. Its importance in personalized medicine is becoming increasingly relevant, as well as gaining more attention in data analytics given the difficulty of analysis in very high dimensional spaces. Transposable elements make up a large fraction of the genome and are responsible for much of the mass of DNA in a eukaryotic cell. Although TEs are selfish genetic elements, many are important in genome function and evolution. Transposons are also very useful to researchers as a means to alter DNA inside a living organism. There are at least two classes of TEs: Class I TEs or retrotransposons generally functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomelo
The pomelo ( ), ''Citrus maxima'', is the largest citrus fruit from the family Rutaceae and the principal ancestor of the grapefruit. It is a natural, non-hybrid, citrus fruit, native to Southeast Asia. Similar in taste to a sweet grapefruit, the pomelo is commonly consumed and used for festive occasions throughout Southeast Asia. As with the grapefruit, phytochemicals in the pomelo have the potential for drug interactions. Etymology and common names According to the Oxford English Dictionary, the etymology of the word "pomelo" is uncertain. It may be derived from Dutch ''pompelmoes''. Its botanical name, ''Citrus maxima'', means "the biggest citrus". In English, the word "pomelo" (also spelled pummelo, pumelo, pomello, pommelo) has become the more common name, although "pomelo" has historically been used for grapefruit. After introduction to Barbados by 'Captain Shaddock' of the East India Company (apparently Philip Chaddock, who visited the island in the late 1640s), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introgression
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species. Introgression also differs from simple hybridization. Simple hybridization results in a relatively even mixture; gene and allele frequencies in the first generation will be a uniform mix of two parental species, such as that observed in mules. Introgression, on the other hand, results in a complex, highly variable mixture of genes, and may only involve a minimal percentage of the donor genome. Definition Introgression or introgressive hybridi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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