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Cleistogamy
Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, peas, and pansies, this behavior is most widespread in the grass family. However, the largest genus of cleistogamous plants is ''Viola''. The more common opposite of cleistogamy, or "closed marriage", is called chasmogamy, or "open marriage". Virtually all plants that produce cleistogamous flowers also produce chasmogamous ones.Meeuse, Bastiaan and Sean Morris. 1984. The sex life of flowers. New York, NY: Facts on File Publishers. pp 110-111. The principal advantage of cleistogamy is that it requires fewer plant resources to produce seeds than does chasmogamy, because development of petals, nectar and large amounts of pollen is not required. This efficiency makes cleistogamy particularly useful for seed production on unfavorable sites or adverse conditions. ''Impatiens capensis,'' for example, has been o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chasmogamy
Chasmogamy, is a plant reproductive mechanism in which pollination occurs in chasmogamous flowers. Chasmogamous flowers are commonly showy with open petals encircling exposed reproductive parts. Chasmogamous stems from Greek for "open marriage", named after the open arrangement of floral structures. Once chasmogamous flowers have reached maturity, they unfurl and their stamens and/or style are made available for pollination. Although some plant species possess self-fertilizing chasmogamous flowers, most chasmogamous flowers are cross-pollinated by biotic (e.g. insects) or abiotic (e.g. wind) agents. Chasmogamous flowers that are cross-pollinated have the advantage of sexual reproduction between two different parents, resulting in sexual recombination and genetically distinct seeds. These distinct seeds increase genetic diversity of the plant population and reduce inbreeding depression and deleterious alleles. Seeds produced by chasmogamous flowers that are cross-pollinated, may a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-pollination
Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to the stigma of the same flower; in geitonogamy, pollen is transferred from the anther of one flower to the stigma of another flower on the same flowering plant, or from microsporangium to ovule within a single ( monoecious) gymnosperm. Some plants have mechanisms that ensure autogamy, such as flowers that do not open (cleistogamy), or stamens that move to come into contact with the stigma. The term selfing that is often used as a synonym, is not limited to self-pollination, but also applies to other types of self-fertilization. Occurrence Few plants self-pollinate without the aid of pollen vectors (such as wind or insects). The mechanism is seen most often in some legumes such as peanuts. In another legume, soybeans, the flowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peanut
The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible seeds. It is widely grown in the tropics and subtropics, important to both small and large commercial producers. It is classified as both a grain legume and, due to its high oil content, an oil crop. World annual production of shelled peanuts was 44 million tonnes in 2016, led by China with 38% of the world total. Atypically among legume crop plants, peanut pods develop underground (geocarpy) rather than above ground. With this characteristic in mind, the botanist Carl Linnaeus gave peanuts the specific epithet ''hypogaea'', which means "under the earth." The peanut belongs to the botanical family Fabaceae (or Leguminosae), commonly known as the legume, bean, or pea family. Like most other legumes, peanuts harbor symbiotic nitrogen-fixing bacteria in root nodules. The capacity to fix nitrogen means peanuts require less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pansy
The garden pansy (''Viola'' × ''wittrockiana'') is a type of large-flowered hybrid plant cultivated as a garden flower. It is derived by hybridization from several species in the section ''Melanium'' ("the pansies") of the genus ''Viola'', particularly '' Viola tricolor'', a wildflower of Europe and western Asia known as heartsease. It is sometimes known as ''Viola tricolor'' var. ''hortensis'', but this scientific name is ambiguous. While ''Viola tricolor'' var. ''hortensis'' Groenland & Rümpler is a synonym of ''Viola'' × ''wittrockiana'', ''Viola tricolor'' var. ''hortensis'' DC. refers to a horticultural variety of wild pansy ('' Viola tricolor'' without interspecific hybridization) that had been illustrated in ''Flora Danica'' in 1777 before the existence of ''Viola'' × ''wittrockiana''. The chromosome number of ''Viola'' × ''wittrockiana'' is 2n = 44–52, with most cultivars being 2n = 48. The flower is in diameter and has two slightly overlapping upper petals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viola (plant)
''Viola'' is a genus of flowering plants in the violet family Violaceae. It is the largest genus in the family, containing between 525 and 600 species. Most species are found in the temperate Northern Hemisphere; however, some are also found in widely divergent areas such as Hawaii, Australasia, and the Andes. Some ''Viola'' species are perennial plants, some are annual plants, and a few are small shrubs. Many species, varieties and cultivars are grown in gardens for their ornamental flowers. In horticulture the term pansy is normally used for those multi-colored, large-flowered cultivars which are raised annually or biennially from seed and used extensively in bedding. The terms viola and violet are normally reserved for small-flowered annuals or perennials, including the wild species. Description Annual or perennial caulescent or acaulescent (with or without a visible plant stem above the ground) herbs, shrubs or very rarely treelets. In acaulescent taxa the foliage and f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impatiens Capensis
''Impatiens capensis'', the orange jewelweed, common jewelweed, spotted jewelweed, jewelweed, spotted touch-me-not, or orange balsam, is an annual plant in the family Balsaminaceae that is native to North America. It is common in bottomland soils, ditches, and along creeks, often growing side by side with its less common relative, yellow jewelweed (''I. pallida''). Description Jewelweed is an herbaceous plant that grows tall and blooms from late spring to early fall. The flowers are orange (sometimes blood orange or rarely yellow) with a three-lobed corolla; one of the calyx lobes is colored similarly to the corolla and forms a hooked conical spur at the back of the flower. Plants may also produce non-showy cleistogamous flowers, which do not require cross-pollination. It often branches extensively. The round stems are glabrous (smooth) and succulent, and semi-translucent, with swollen or darkened nodes on some plants. The leaves, which measure up to long and across, are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are posi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA replication, DNA or viral replication, mitosis, or meiosis or other types of DNA repair#DNA damage, damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (DNA repair#Translesion synthesis, translesion synthesis). Mutations may also result from Insertion (genetics), insertion or Deletion (genetics), deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetically Modified Organism
A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in a way that "does not occur naturally by mating and/or natural recombination". A wide variety of organisms have been genetically modified (GM), from animals to plants and microorganisms. Genes have been transferred within the same species, across species (creating transgenic organisms), and even across kingdoms. New genes can be introduced, or endogenous genes can be enhanced, altered, or knocked out. Creating a genetically modified organism is a multi-step process. Genetic engineers must isolate the gene they wish to insert into the host organism and combine it with other genetic elements, including a promoter and terminator region and often a selectable marker. A number of techniques ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapeseed
Rapeseed (''Brassica napus ''subsp.'' napus''), also known as rape, or oilseed rape, is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed, which naturally contains appreciable amounts of erucic acid. The term ''canola'' denotes a group of rapeseed cultivars which were bred to have very low levels of erucic acid and are especially prized for use as human and animal food. Rapeseed is the third-largest source of vegetable oil and the second-largest source of protein meal in the world. Description ''Brassica napus'' grows to in height with hairless, fleshy, pinnatifid and glaucous lower leaves which are stalked whereas the upper leaves have no petioles. ''Brassica napus'' can be distinguished from ''Brassica nigra'' by the upper leaves which do not clasp the stem, and from ''Brassica rapa'' by its smaller petals which are less than across. Rapeseed flowers are bright yellow and about across. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Flow
In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent allele frequencies and therefore can be considered a single effective population. It has been shown that it takes only "one migrant per generation" to prevent populations from diverging due to drift. Populations can diverge due to selection even when they are exchanging alleles, if the selection pressure is strong enough. Gene flow is an important mechanism for transferring genetic diversity among populations. Migrants change the distribution of genetic diversity among populations, by modifying allele frequencies (the proportion of members carrying a particular variant of a gene). High rates of gene flow can reduce the genetic differentiation between the two groups, increasing homogeneity. For this reason, gene flow has been thought to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Co-Extra
Co-Extra was an EU-funded research programme on ''co-ex''istence and ''tra''ceability of genetically modified crops and their edible derivatives that ran from 2005-2009. It was granted €13.5 million under the Sixth Framework Programme of the European Union, and is conducted by more than 200 scientists in 52 organisations in 18 countries. Research goals The research programme studied and validated biological containment One use of the concept of biocontainment is related to laboratory biosafety and pertains to microbiology laboratories in which the physical containment of pathogenic organisms or agents (bacteria, viruses, and toxins) is required, usually by is ... methods, forged supply chain organisations, and provided practical tools and methods for implementing co-existence between GMO-based (i.e., based on the use of genetically modified organisms) and non-GMO-based supply chains. With regard to supporting cost-effective documentary traceability, Co-Extra was aimed at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
