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Tachibana Orange
The tachibana orange (''Citrus'' × ''tachibana'', or ''Citrus reticulata'' subsp. ''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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Taxonomic Information System
The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagency group within the US federal government, involving several US federal agencies, and has now become an international body, with Canadian and Mexican government agencies participating. The database draws from a large community of taxonomic experts. Primary content staff are housed at the Smithsonian National Museum of Natural History and IT services are provided by a US Geological Survey facility in Denver. The primary focus of ITIS is North American species, but many biological groups exist worldwide and ITIS collaborates with other agencies to increase its global coverage. Reference database ITIS provides an automated reference database of scientific and common names for species. it contains over 839,000 scientific names, synonyms, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposable Element
A transposable element (TE), also transposon, or jumping gene, is a type of mobile genetic element, a nucleic acid sequence in DNA that can change its position within a genome. The discovery of mobile genetic elements earned Barbara McClintock a Nobel Prize in 1983. There are at least two classes of TEs: Class I TEs or retrotransposons generally function via reverse transcription, while Class II TEs or DNA transposons encode the protein transposase, which they require for insertion and excision, and some of these TEs also encode other proteins. Discovery by Barbara McClintock Barbara McClintock discovered the first TEs in maize (''Zea mays'') at the Cold Spring Harbor Laboratory in New York. McClintock was experimenting with maize plants that had broken chromosomes. In the winter of 1944–1945, McClintock planted corn kernels that were self-pollinated, meaning that the silk (style) of the flower received pollen from its own anther. These kernels came from a long line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus
''Citrus'' is a genus of flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, mandarins, lemons, grapefruits, pomelos, and limes. ''Citrus'' is native to South Asia, East Asia, Southeast Asia, Melanesia, and Australia. Indigenous people in these areas have used and domesticated various species since ancient times. Its cultivation first spread into Micronesia and Polynesia through the Austronesian expansion (–1500 BCE). Later, it was spread to the Middle East and the Mediterranean () via the incense trade route, and from Europe to the Americas. Renowned for their highly fragrant aromas and complex flavor, citrus are among the most popular fruits in cultivation. With a propensity to hybridize between species, making their taxonomy complicated, there are numerous varieties encompassing a wide range of appearance and fruit flavors. Evolution Evolutionary history The large cit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Dispersal
Oceanic dispersal is a type of biological dispersal that occurs when Terrestrial animal, 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 (Year#SI prefix multipliers, Ma), and South America, which was isolated for much of the Cenozoic. Both lan ... [...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 ice age called Quaternary glaciation. Individual pulses of cold climate within an ice age are termed '' glacial periods'' (''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, the term ''ice age'' is defined by the presence of extensive ice sheets in the northern and southern hemispheres. By this definition, the current Holocene epoch is an interglacial period of an ice age. The accumulation of anthropogenic greenhouse gases is projected to delay the next glacial period. History of research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from 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 () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...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 Former land bridges * The Bassian Plain, which linked Australia to Tasmania * The Antarctic Land Bridge, which connected South America, Antarctica, and Australia during the Late Cretaceous and Early Paleogene * 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 * GAARlandia, a hypothesized land bridge which potentially connected the Greater Antilles with South America d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after India, representing 17.4% of the world population. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land across an area of nearly , making it the list of countries and dependencies by area, third-largest country by land area. The country is divided into 33 Province-level divisions of China, province-level divisions: 22 provinces of China, provinces, 5 autonomous regions of China, autonomous regions, 4 direct-administered municipalities of China, municipalities, and 2 semi-autonomous special administrative regions. Beijing is the country's capital, while Shanghai is List of cities in China by population, its most populous city by urban area and largest financial center. Considered one of six ... [...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 their branches, the mountains run west to east . There are trough basins in the Nanling; most of the western basins in Nanling Mountains are composed of limestone, where karst regions are located. Most of the eastern basins are made up of red sandstone, where danxia landform areas are found. The Nanling are boundaries between the four provinces of Guangdong, Guangxi, Hunan and Jiangxi, and also the cultural boundaries. To the south of the mountains are Lingnan culture areas.ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apomixis
In botany, apomixis is asexual development of seed or embryo without fertilization. However, other definitions include replacement of the seed by a plantlet or replacement of the flower by bulbils. Apomictically produced offspring are genetically identical to the parent plant, except in nonrecurrent apomixis. Its etymology is Greek for "away from" + "mixing". Normal asexual reproduction of plants, such as propagation from cuttings or leaves, has never been considered to be apomixis. In contrast to parthenocarpy, which involves seedless fruit formation without fertilization, apomictic fruits have viable seeds containing a proper embryo, with asexual origin. In flowering plants, the term "apomixis" is 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomelo
The pomelo ( ; or pummelo, ''Citrus maxima''), also known as a shaddock, is the largest citrus fruit. It is an ancestor of several cultivated citrus species, including the bitter orange and 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 eaten and used for festive occasions throughout Southeast and East Asia. As with the grapefruit, phytochemicals in the pomelo have the potential for drug interactions. Description The pomelo tree may be tall, with a trunk, often rather crooked, that is thick, and low-hanging, irregular branches. The petioles (leaf stalks) are distinctly winged. The leaves are alternate, ovate or elliptic in shape and long; they are leathery and dull green above, hairy beneath. The flowers – single or in clusters – are fragrant and yellow-white in color. The fruit is large, in diameter, round or somewhat pear-shaped. Its weight varies by cultivar fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandarin Orange
A mandarin orange (''Citrus reticulata''), often simply called mandarin, is a small, rounded citrus tree fruit. Treated as a distinct species of orange, it is usually eaten plain or in fruit salads. The mandarin is small and oblate, unlike the roughly spherical sweet orange (which is a mandarin- pomelo hybrid). The taste is sweeter and stronger than the common orange. A ripe mandarin orange is firm to slightly soft, heavy for its size, and pebbly-skinned. The peel is thin and loose, with little white mesocarp, so they are usually easier to peel and to split into segments. Hybrids have these traits to lesser degrees. The mandarin orange is tender and is damaged easily by cold. It can be grown in tropical and subtropical areas. According to genetic studies, the wild mandarin was one of the original citrus species; through breeding or natural hybridization, it is the ancestor of many hybrid citrus cultivars. With the citron and pomelo, it is the ancestor of the most commerci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
